{"name":"缝纫机装配调试专项职业能力题库","level":"不分级","org":"人力资源和社会保障部门","count":300,"questions":[{"id":1,"type":"single","stem":"工业平缝机装配时，针杆下端面与针板平面之间的距离应通过什么零件来调整","options":["针杆连接柱的夹紧螺钉","针杆曲柄上的油孔","压脚杆调节螺钉","送布牙偏心轮"],"answer":[0],"explanation":"知识点是针杆高度调整。针杆连接柱夹紧螺钉松开后可上下移动针杆，从而改变针杆下端面与针板平面的距离，正确项对；针杆曲柄油孔只负责润滑，不能改变针杆高度；压脚杆调节螺钉控制压脚压力而非针杆高度；送布牙偏心轮负责送布牙高度，与针杆高度无关。","tier":"进阶"},{"id":2,"type":"single","stem":"平缝机试缝时出现上线浮在布料下面、底线露出布面的现象，最可能的原因是","options":["夹线器压力过大","梭皮螺钉拧得过紧","挑线簧弹力过弱","旋梭勾线时间过早"],"answer":[2],"explanation":"知识点是线迹张力平衡。上线浮在下面说明上线张力小于底线张力，挑线簧弹力过弱使上线收线不足，正确项对；夹线器压力过大会使上线更紧，现象相反；梭皮螺钉过紧是底线变紧，与上线松不符；旋梭勾线时间过早影响跳针而非线迹浮线。","tier":"进阶"},{"id":3,"type":"single","stem":"工业包缝机装配后试车，发现上弯针与下弯针在交叉处相碰，正确的调整部位是","options":["上弯针夹紧螺钉和弯针座","压脚压力调节螺母","送布牙前后位置螺钉","针杆高度调节螺钉"],"answer":[0],"explanation":"知识点是包缝机弯针配合。上弯针夹紧螺钉和弯针座可改变上弯针的前后、左右位置，消除与下弯针的碰撞，正确项对；压脚压力调节螺母控制压料力，与弯针碰撞无关；送布牙前后位置螺钉调送布量；针杆高度调节螺钉调针杆高低。","tier":"挑战"},{"id":4,"type":"single","stem":"装配平缝机下轴时，下轴轴向窜动量应控制在什么范围","options":["0.01～0.04mm","0.1～0.3mm","0.5～0.8mm","1.0～1.5mm"],"answer":[0],"explanation":"知识点是下轴轴向间隙。下轴轴向窜动量应为0.01～0.04mm，过大影响旋梭勾线稳定，正确项对；0.1～0.3mm偏大易引起旋梭轴向窜动；0.5～0.8mm明显过大；1.0～1.5mm属严重超差。","tier":"基础"},{"id":5,"type":"single","stem":"装配平缝机挑线杆时，挑线杆过线孔出现毛刺，正确的处理方法是","options":["用细油石或金相砂纸修光过线孔","用粗锉刀快速去毛刺","用锤子轻敲过线孔边缘","涂一层黄油覆盖毛刺"],"answer":[0],"explanation":"知识点是过线部位表面质量。过线孔毛刺会割断缝线，应用细油石或金相砂纸修光，正确项对；粗锉刀会留下更粗痕迹；锤子敲击会变形；涂黄油不能消除毛刺且污染缝线。","tier":"基础"},{"id":6,"type":"single","stem":"平缝机装配完成后进行空运转试验，通常要求连续运转多长时间并检查温升和噪声","options":["约5分钟","约30分钟","约2小时","约8小时"],"answer":[1],"explanation":"知识点是空运转试验规范。平缝机装配后一般空运转约30分钟，检查各轴承温升和噪声是否正常，正确项对；5分钟太短来不及观察温升；2小时和8小时属长时间耐久试验，不是常规空运转要求。","tier":"基础"},{"id":7,"type":"single","stem":"工业平缝机装配时，针杆下端面与针板平面的距离应调整到多少","options":["7mm","10mm","15mm","20mm"],"answer":[0],"explanation":"知识点：针杆高度基准。平缝机针杆下端面到针板平面标准距离约7mm，保证机针下死点时能形成正常线环。10mm偏大，线环形成时机过晚；15mm明显超出常规范围，会导致跳针；20mm完全无法形成有效线环。","tier":"基础"},{"id":8,"type":"single","stem":"平缝机旋梭与机针的配合中，机针从下死点回升多少时旋梭尖应到达机针中心线","options":["1.5mm","2.2mm","3.0mm","4.0mm"],"answer":[1],"explanation":"知识点：旋梭勾线时机。机针回升约2.2mm时旋梭尖到达机针中心线是标准勾线时机。1.5mm回升量偏小，线环尚未充分形成；3.0mm回升量偏大，旋梭尖可能勾不到线环；4.0mm时线环已收缩变形，勾线失败率极高。","tier":"基础"},{"id":9,"type":"single","stem":"工业平缝机装配后试缝出现布料背面线迹浮线，面线张力正常，最可能的原因是","options":["旋梭定位钩间隙过大","底线张力过小","挑线簧弹力过大","针距调节盘松动"],"answer":[1],"explanation":"知识点：线迹形成与张力配合。背面浮线通常是底线张力不足，底线被面线拉过布料。旋梭定位钩间隙过大影响勾线稳定性，不直接造成背面浮线；挑线簧弹力过大会使面线收线过紧，表现为正面浮线；针距调节盘松动影响针距均匀度而非线迹松紧。","tier":"进阶"},{"id":10,"type":"single","stem":"装配高速包缝机时，上弯针与下弯针的交叉间隙应调整为","options":["0.5~1.0mm","1.5~2.0mm","2.5~3.0mm","3.5~4.0mm"],"answer":[0],"explanation":"知识点：包缝机弯针配合。上下弯针交叉时标准间隙为0.5~1.0mm，保证两者能可靠交接缝线。1.5~2.0mm间隙过大，缝线交接时容易脱钩；2.5~3.0mm和3.5~4.0mm间隙远超标准，弯针无法正常勾线，会直接跳针。","tier":"基础"},{"id":11,"type":"single","stem":"工业平缝机送布牙高度调整时，送布牙上升到最高点时露出针板平面的标准高度是","options":["0.3~0.5mm","0.8~1.0mm","1.5~2.0mm","2.5~3.0mm"],"answer":[1],"explanation":"知识点：送布牙高度标准。送布牙最高点露出针板0.8~1.0mm是常规标准，能保证送布力又不刮伤布料。0.3~0.5mm露出过少，送布无力易打滑；1.5~2.0mm露出过多，薄料会起皱、厚料送布不稳；2.5~3.0mm严重超差，送布牙会顶起压脚造成送料异常。","tier":"基础"},{"id":12,"type":"single","stem":"平缝机运转时出现周期性刺耳金属摩擦声，用手转动上轮感觉某角度阻力明显增大，最应优先检查的部位是","options":["旋梭与梭壳的配合间隙","挑线杆与挑线簧的安装","针杆与上下套筒的润滑","压脚与送布牙的啮合"],"answer":[0],"explanation":"知识点：运转异响与阻力判断。周期性摩擦声且某角度阻力增大，通常是旋梭与梭壳间隙不当或旋梭内部有异物。挑线簧问题表现为张力波动而非周期性摩擦；针杆缺油表现为持续干涩声；压脚与送布牙啮合异常表现为送料不畅而非转轮阻力。","tier":"进阶"},{"id":13,"type":"single","stem":"装配绷缝机时，弯针前后运动行程的调整目的是保证","options":["弯针能穿过机针线环并形成缝线交接","弯针能避开针板边缘防止碰撞","弯针能带动缝料向前输送","弯针能压住缝料防止跳动"],"answer":[0],"explanation":"知识点：绷缝机弯针运动功能。弯针前后运动行程调整的核心目的是使弯针尖准确穿过机针形成的线环，完成缝线交接。避开针板边缘是行程限位的基本要求而非调整目的；带动缝料输送是送布牙功能；压住缝料是压脚功能。","tier":"基础"},{"id":14,"type":"single","stem":"平缝机在缝制薄料时出现布料被送布牙啃出齿痕，送布牙高度正常，应优先调整","options":["减小送布牙前后行程","降低压脚压力","增大面线张力","调快缝纫速度"],"answer":[1],"explanation":"知识点：压脚压力与送布配合。薄料出现齿痕通常是压脚压力过大，使送布牙齿尖压入布料。减小送布牙前后行程影响针距而非齿痕；增大面线张力会加剧布料收缩起皱；调快缝纫速度不会改善齿痕，反而可能加重。","tier":"基础"},{"id":15,"type":"single","stem":"某平缝机在低速试缝正常，高速运转时出现跳针，旋梭勾线时机和针杆高度均已校准，下一步应重点检查","options":["机针是否弯曲或针尖变钝","缝线是否穿过挑线簧","梭壳是否装入旋梭","针板螺钉是否拧紧"],"answer":[0],"explanation":"知识点：高速跳针的常见原因。低速正常高速跳针，在勾线时机和针杆高度已校准的前提下，最常见原因是机针弯曲或针尖磨损，高速时线环形成不稳定。缝线未穿过挑线簧会导致收线异常而非仅高速跳针；梭壳未装入则完全无法缝纫；针板螺钉未拧紧表现为振动和噪音。","tier":"进阶"},{"id":16,"type":"single","stem":"装配工业包缝机时，操作者发现下弯针尖与机针的间隙为0.3mm，按标准应调整为","options":["0.05~0.1mm","0.15~0.2mm","0.5~0.8mm","1.0~1.5mm"],"answer":[0],"explanation":"知识点：包缝机弯针与机针间隙标准。下弯针尖与机针间隙应为0.05~0.1mm，间隙过大会导致弯针勾不到机针线环。0.15~0.2mm偏大，薄料易跳针；0.5~0.8mm明显过大，缝线交接不可靠；1.0~1.5mm完全无法正常勾线。","tier":"挑战"},{"id":17,"type":"single","stem":"工业平缝机装配后，针杆在下死点时，针尖与针板孔中心的偏移量应控制在什么范围内","options":["0～0.1mm","0.3～0.5mm","0.8～1.0mm","1.5～2.0mm"],"answer":[0],"explanation":"知识点：针杆与针板孔的同心度要求。正确项对：针尖须正对针板孔中心，偏移过大会导致断针、跳针，标准控制在0～0.1mm。错误项错在：0.3～0.5mm偏大，实际作业中会造成机针碰擦针板孔边缘；0.8～1.0mm已明显偏心，送布时容易断针；1.5～2.0mm属严重偏移，机针无法正常穿刺缝料。","tier":"基础"},{"id":18,"type":"single","stem":"平缝机旋梭与机针的配合时机中，当机针从下死点回升多少距离时，旋梭梭尖应到达机针中心线","options":["0.5mm","2.2mm","5.0mm","8.0mm"],"answer":[1],"explanation":"知识点：旋梭勾线时机的调整。正确项对：机针从下死点回升约2.2mm时梭尖应到达针中心线，此时针孔上方形成最佳线环。错误项错在：0.5mm时机针回升不足，线环尚未形成；5.0mm回升过大，线环已扭曲变形；8.0mm机针已回升过高，旋梭无法勾住线环。","tier":"基础"},{"id":19,"type":"single","stem":"工业包缝机在装配时，若上弯针与下弯针的交叉间隙过小，最容易引发下列哪种故障","options":["弯针相互碰撞磨损","线迹张力过紧","针距忽大忽小","压脚压力不足"],"answer":[0],"explanation":"知识点：包缝机弯针配合间隙。正确项对：上下弯针交叉处需留0.05～0.1mm间隙，过小会直接碰撞磨损。错误项错在：线迹张力过紧由夹线器调节决定，与弯针间隙无关；针距忽大忽小源于送布牙与压脚配合；压脚压力不足由压簧调节控制。","tier":"基础"},{"id":20,"type":"single","stem":"平缝机送布牙露出针板平面的高度，在缝制中厚料时应调整到多少","options":["0.3～0.5mm","0.8～1.0mm","1.5～2.0mm","2.5～3.0mm"],"answer":[1],"explanation":"知识点：送布牙高度与缝料厚度的匹配。正确项对：中厚料通常调至0.8～1.0mm，既保证送布有力又不刮伤缝料。错误项错在：0.3～0.5mm适合薄料，中厚料会送布打滑；1.5～2.0mm过高，会造成缝料起皱和噪音；2.5～3.0mm严重过高，送布牙会刮破缝料。","tier":"基础"},{"id":21,"type":"single","stem":"绷缝机在调试时发现线迹背面出现浮线，而正面线迹正常，最应先检查的部位是","options":["上弯针的勾线时机","下弯针的线张力","压脚的提升高度","针板的孔径尺寸"],"answer":[1],"explanation":"知识点：绷缝机浮线故障的排查顺序。正确项对：背面浮线多因下弯针线张力过松，应先检查其夹线器。错误项错在：上弯针勾线时机异常会同时影响正反面线迹；压脚提升高度影响压料不影响线张力；针板孔径过大会引起跳针而非浮线。","tier":"挑战"},{"id":22,"type":"single","stem":"装配工业缝纫机时，主轴与上轴采用同步带传动，若同步带张紧度过松，运转中最可能出现的现象是","options":["缝纫速度偏高","针距不稳定和噪音增大","电机电流下降","压脚压力减弱"],"answer":[1],"explanation":"知识点：同步带张紧度对传动精度的影响。正确项对：张紧过松会使带齿跳齿，导致针距不稳、噪音增大。错误项错在：缝纫速度由电机转速决定；电机电流会因打滑反而波动或上升；压脚压力由独立压簧调节，与同步带无关。","tier":"基础"},{"id":23,"type":"single","stem":"在装配平缝机挑线杆组件时，挑线杆过线孔出现毛刺，正确的处理方式是","options":["用细油石或金相砂纸修磨抛光","用粗锉刀修整后直接装配","涂少量润滑油后继续装配","用锤子轻敲使毛刺压平"],"answer":[0],"explanation":"知识点：过线部位表面质量要求。正确项对：过线孔毛刺须用细油石或金相砂纸修磨抛光，避免割断缝线。错误项错在：粗锉刀会留下更深的划痕；涂油不能消除毛刺；锤击会使孔变形并产生新的锐边。","tier":"进阶"},{"id":24,"type":"single","stem":"平缝机在高速运转时出现机针与旋梭相碰的声音，停机检查发现梭尖已轻微磨损，正确的处理顺序是","options":["先更换旋梭并重新校准勾线时机，再试缝确认","先调大针杆高度，再观察是否还有碰擦","先降低缝纫速度使用，待磨损加重再换","先更换机针，再调整旋梭供油量"],"answer":[0],"explanation":"知识点：机针与旋梭碰擦的处置流程。正确项对：梭尖磨损后必须更换旋梭并重新校准勾线时机，才能根除碰擦。错误项错在：调针杆高度不能修复已磨损梭尖；降速使用会加剧磨损并损伤机针；换机针和调油量都不解决碰擦根源。","tier":"挑战"},{"id":25,"type":"single","stem":"工业平缝机装配时，针杆下套筒压入机头后出现转动发涩，最应优先检查的是哪一项","options":["套筒外径与机头孔配合过盈量是否偏大","针杆与套筒间隙是否因油污变小","机头孔内是否残留铁屑或毛刺","针杆上端是否已经装入挑线杆"],"answer":[2],"explanation":"知识点是过盈配合装配前的孔壁清洁。压入后发涩多因孔内有铁屑或毛刺造成局部挤压，应先查孔壁；过盈量偏大会在压入前就明显难压且需重新选配，不是首选；油污一般不会使新装套筒发涩到转动困难；挑线杆是否装上与套筒转动发涩无直接关系。","tier":"进阶"},{"id":26,"type":"single","stem":"旋梭与机针的配合中，机针从最低点回升开始形成线环时，梭尖应位于机针中心的什么位置","options":["机针中心线略上方且贴近针杆","机针中心线略下方且贴近针杆","机针缺口上缘以上约 2mm 处","机针缺口下缘以下约 2mm 处"],"answer":[1],"explanation":"知识点是旋梭勾线时机。机针回升形成线环时，梭尖应在机针中心线略下方并贴近针杆，才能稳定勾住线环；略上方会勾不到线环；缺口上缘以上和缺口下缘以下都偏离了标准勾线位置，会造成跳线或断线。","tier":"进阶"},{"id":27,"type":"single","stem":"包缝机装配后试缝发现链线弯针线张力偏大，调整时首先应确认的是哪一项","options":["弯针前后行程是否已按厚料调大","弯针线是否穿过了所有规定的过线孔","上弯针与下弯针的交叉量是否为零","压脚压力是否已调到最大"],"answer":[1],"explanation":"知识点是包缝机线张力调整前的穿线检查。线张力偏大常因穿线路径漏穿或错穿造成，应先确认弯针线穿过所有规定过线孔；弯针行程按厚料调大是另一调整项目，不是张力偏大先查项；交叉量为零属勾线配合问题；压脚压力调到最大与弯针线张力无直接关系。","tier":"挑战"},{"id":28,"type":"single","stem":"某厂装配高速平缝机时，主轴转动灵活但装上同步带后负载明显增大，最可能的原因是","options":["同步带张力过大或带轮不平行","主轴前后轴承预紧量偏小","针距调节机构未回到零位","挑线杆行程未调整到位"],"answer":[0],"explanation":"知识点是同步带传动装配。装上同步带后负载增大，多因带张力过大或两带轮不平行使附加径向力增加；轴承预紧量偏小会使主轴更松而非负载增大；针距未回零影响送布但不直接使主轴负载增大；挑线杆行程影响收线，不直接造成主轴负载。","tier":"进阶"},{"id":29,"type":"single","stem":"平缝机试缝时出现面料背面线迹浮线，且梭芯线张力明显偏松，正确的调整顺序是","options":["先调大梭芯线张力再复查面线张力","先调大面线张力再复查梭芯线张力","先调大压脚压力再复查梭芯线张力","先调大送布牙高度再复查面线张力"],"answer":[0],"explanation":"知识点是浮线的张力调整顺序。背面浮线且梭芯线偏松，应先调大梭芯线张力再复查面线张力；先调面线会掩盖梭芯线松的问题；压脚压力影响送布不解决张力配比；送布牙高度影响线迹长度不直接解决浮线。","tier":"进阶"},{"id":30,"type":"single","stem":"装配缝纫机挑线杆机构时，挑线杆过线孔出现明显毛刺，正确的处理方式是","options":["用细砂纸沿孔口单向轻轻修去毛刺并抛光","用锉刀横向用力锉削孔口使毛刺脱落","直接换用大一号的挑线杆过线孔零件","在孔口涂少量机油后继续装配使用"],"answer":[0],"explanation":"知识点是过线部位表面处理。过线孔毛刺应用细砂纸沿孔口单向轻修并抛光，避免损伤过线面；锉刀横向用力会改变孔口几何形状；换大一号孔会改变过线位置和张力；涂油不能消除毛刺，仍会割伤缝线。","tier":"进阶"},{"id":31,"type":"single","stem":"某台平缝机在缝制薄料时线迹正常，换厚料后出现断针，最应先检查的是","options":["机针是否因厚料改用粗一号且针杆高度正确","梭芯线张力是否因厚料调得过松","压脚压力是否因厚料调得过小","送布牙是否因厚料调得过低"],"answer":[0],"explanation":"知识点是厚料断针的机针与针杆检查。换厚料后断针应先确认机针是否改用合适粗号且针杆高度正确；梭芯线张力过松不会直接断针；压脚压力过小会使送布不稳但不直接断针；送布牙过低影响送布量，不直接造成断针。","tier":"进阶"},{"id":32,"type":"single","stem":"装配绷缝机时，前后弯针的交叉配合调整不到位，最容易直接造成的线迹缺陷是","options":["线迹出现跳针或漏针","线迹出现规律性浮线","线迹出现针距不均匀","线迹出现面料起皱"],"answer":[0],"explanation":"知识点是绷缝机弯针交叉配合。前后弯针交叉配合不到位会直接造成跳针或漏针；规律性浮线多与张力有关；针距不均匀多与送布机构有关；面料起皱多与压脚压力或差动比有关。","tier":"进阶"},{"id":33,"type":"single","stem":"某维修工在调试平缝机时，用螺丝刀直接敲击针杆下端来调整针杆高度，这种做法的主要问题是","options":["敲击会使针杆弯曲或套筒配合面损伤","敲击会使针杆表面镀层更耐磨","敲击会使针杆与套筒间隙自动变小","敲击会使针杆高度更易微调"],"answer":[0],"explanation":"知识点是针杆调整的规范操作。敲击针杆下端易使针杆弯曲或损伤套筒配合面；敲击不会提高耐磨性；敲击不会使间隙自动变小；敲击无法实现精确微调，反而破坏精度。","tier":"进阶"},{"id":34,"type":"single","stem":"平缝机装配完成后试缝，发现针距调节盘指示值与实际针距不符，正确的排查顺序是","options":["先查送布牙架连接是否松动再查针距机构限位","先查压脚压力再查送布牙高度","先查梭芯线张力再查面线张力","先查机针型号再查针杆高度"],"answer":[0],"explanation":"知识点是针距指示与实际不符的排查。应先查送布牙架连接是否松动，再查针距机构限位是否准确；压脚压力和送布牙高度影响送布效果但不直接造成指示不符；张力与针距指示无关；机针型号和针杆高度与针距指示无关。","tier":"挑战"},{"id":35,"type":"multi","stem":"平缝机装配后试缝出现跳线，下列排查方向中与跳线直接相关的有","options":["机针是否装反或针尖变钝","梭尖与机针的勾线时机是否偏移","梭芯线是否穿错或梭壳未装到位","压脚底面是否已抛光","机头外表面是否已喷漆均匀"],"answer":[0,1,2],"explanation":"知识点是跳线的常见原因。机针装反或针尖变钝、梭尖勾线时机偏移、梭芯线穿错或梭壳未装到位都会直接造成跳线；压脚底面抛光与跳线无直接关系；机头外表面喷漆属外观工序，与跳线无关。","tier":"进阶"},{"id":36,"type":"single","stem":"工业平缝机装配时，针杆下端的针杆过线器（挑线钩）安装方向应满足的要求是","options":["钩口朝向操作者左侧且过线孔与针杆轴线垂直","钩口朝向机头内侧且过线孔与针杆轴线平行","钩口朝向操作者右侧且过线孔与针杆轴线垂直","钩口朝向机头外侧且过线孔与针杆轴线平行"],"answer":[0],"explanation":"知识点：针杆过线器的装配方向。正确项：钩口朝左、过线孔与针杆轴线垂直，才能保证挑线时线不脱钩且不磨线；错误项A钩口朝内会干涉挑线杆运动；错误项B过线孔方向错会使线在针杆处被磨断；错误项C朝右与机头结构不匹配且过线孔方向错。","tier":"进阶"},{"id":37,"type":"single","stem":"装配工业平缝机旋梭时，梭尖与机针中心线的轴向位置关系应调整为","options":["梭尖略高于针孔上沿约1mm","梭尖与针孔上沿平齐","梭尖位于针孔上沿上方约2mm","梭尖位于针孔下沿以下约1mm"],"answer":[1],"explanation":"知识点：旋梭梭尖与机针的配合位置。正确项：梭尖与针孔上沿平齐是标准配合，能可靠勾线；错误项A偏高约1mm会勾线过早跳针；错误项C偏高2mm严重跳针且可能撞针；错误项D偏低会勾不到线造成断线。","tier":"进阶"},{"id":38,"type":"single","stem":"调试工业平缝机挑线杆行程时，若挑线杆在最上位置时挑线量过大，最可能出现的现象是","options":["缝料正面线迹浮线","缝料反面线迹浮线","面线在缝料中间被拉断","底线在旋梭处被割断"],"answer":[0],"explanation":"知识点：挑线量与线迹质量的关系。正确项：挑线量过大使面线收线过紧，反面被拉紧而正面浮线；错误项B反面浮线是挑线量不足的典型表现；错误项C面线中间拉断多与夹线器过紧或针板孔毛刺有关；错误项D底线割断与旋梭梭皮或梭壳毛刺相关。","tier":"进阶"},{"id":39,"type":"single","stem":"工业包缝机装配完成后试缝发现链线弯针与机针的交叉间隙过大，正确的调整操作是","options":["增大弯针前后行程","减小弯针前后行程","调整弯针摆动相位角","更换弯针座弹簧"],"answer":[2],"explanation":"知识点：包缝机弯针与机针交叉间隙的调整。正确项：交叉间隙由弯针摆动相位角决定，调整相位角可改变交叉时机；错误项A前后行程改变的是勾线深度而非交叉间隙；错误项B减小行程同样不改变交叉间隙；错误项D弹簧只影响弯针复位力。","tier":"挑战"},{"id":40,"type":"single","stem":"装配工业绷缝机时，针杆高度调整的依据是","options":["机针针尖与针板面的距离","机针针孔上沿与弯针尖的配合位置","压脚底面与针板面的间隙","送布牙最高点与针板面的高度差"],"answer":[1],"explanation":"知识点：绷缝机针杆高度的调整基准。正确项：针杆高度以针孔上沿与弯针尖配合位置为准，保证弯针可靠勾线；错误项A是针杆最低位置的参考，非高度调整依据；错误项C是压脚压力调整内容；错误项D是送布牙高度调整内容。","tier":"基础"},{"id":41,"type":"single","stem":"工业平缝机送布牙高度调整时，若送布牙最高点低于针板面，缝纫时最可能出现","options":["缝料不走或走料无力","缝料被送布牙刮破","线迹忽长忽短","针距调节盘失效"],"answer":[0],"explanation":"知识点：送布牙高度与送布性能的关系。正确项：送布牙低于针板面时牙齿露不出，无法有效送料；错误项B刮破是送布牙过高或牙尖毛刺造成；错误项C忽长忽短多与压脚压力或送布凸轮松动有关；错误项D针距调节盘失效与牙高无关。","tier":"进阶"},{"id":42,"type":"single","stem":"调试工业平缝机时，缝纫薄料出现针迹起皱，检查发现压脚压力偏大，正确的下一步处置是","options":["减小压脚压力并检查送布牙高度","增大压脚压力并降低针杆高度","减小挑线杆行程并更换细针","增大挑线量并调快缝速"],"answer":[0],"explanation":"知识点：薄料起皱的调试。正确项：压脚压力过大是薄料起皱主因，应先减压并复核送布牙高度；错误项B加压会加剧起皱；错误项C换细针不解决压力问题；错误项D增大挑线量会使面线更紧、起皱更重。","tier":"挑战"},{"id":43,"type":"single","stem":"装配工业平缝机膝控抬压脚机构时，膝控顶杆与抬压脚杠杆的接触位置应满足","options":["顶杆端部与杠杆圆弧面中部接触","顶杆端部与杠杆圆弧面边缘接触","顶杆端部与杠杆平面端面接触","顶杆端部与杠杆侧面斜边接触"],"answer":[0],"explanation":"知识点：膝控抬压脚机构的装配接触要求。正确项：顶杆端部与杠杆圆弧面中部接触，力的传递平稳不偏磨；错误项B接触边缘易滑脱且杠杆偏磨；错误项C平面端面接触会卡滞；错误项D侧面斜边接触力方向偏斜，抬压脚不顺畅。","tier":"进阶"},{"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"知识点：装配后试运转前的机械检查。正确项转动灵活且无卡滞异响，说明各运动副配合间隙与同步正常。转动略紧但能整圈通过说明仍有隐性干涉，负荷会加剧磨损。转动灵活但局部有轻微摩擦声说明某相位存在碰擦，需排查。转动顺畅但针杆不上不下说明针杆机构未连接或离合器脱开，不能试运转。","tier":"进阶"},{"id":80,"type":"single","stem":"调试平缝机挑线杆供线量时，若挑线簧弹力调得过强，缝纫中常出现的现象是","options":["线迹浮线且底线被抽紧","面线收线不足形成抛线","挑线杆行程自动变大","梭芯绕线量明显增加"],"answer":[1],"explanation":"知识点：挑线簧弹力对收线的影响。挑线簧过强会限制挑线杆及时供线，面线收线不足而形成抛线。浮线且底线被抽紧通常是底线张力过大或面线过松。挑线杆行程由凸轮机构决定，不会因挑线簧弹力自动变大。梭芯绕线量由绕线器调节，与挑线簧弹力无直接关系。","tier":"进阶"},{"id":81,"type":"single","stem":"旋梭与机针的配合中，机针从下死点回升时梭尖应到达针孔上方约","options":["0.5mm","1.8mm","3.5mm","5.0mm"],"answer":[1],"explanation":"知识点：旋梭勾线时机。机针回升时梭尖应在针孔上方约1.8mm处勾住面线环。0.5mm过小，线环尚未形成易跳针。3.5mm与5.0mm过大，线环已扭曲或收缩，同样造成跳针或断线。","tier":"基础"},{"id":82,"type":"single","stem":"装配缝纫机送布牙时，牙面高出针板平面的常规范围是","options":["0.2～0.4mm","0.8～1.0mm","1.5～2.0mm","2.5～3.0mm"],"answer":[1],"explanation":"知识点：送布牙高度标准。送布牙齿尖高出针板0.8～1.0mm可保证正常送布且不刮伤面料。0.2～0.4mm偏低，薄料易打滑不走。1.5～2.0mm与2.5～3.0mm偏高，会顶起面料造成起皱或针迹不匀。","tier":"基础"},{"id":83,"type":"single","stem":"工业缝纫机调试时发现压脚压力过大，最可能引起的缝纫质量问题是","options":["缝料上下层错位起皱","面线张力自动变小","梭芯转动阻力下降","针距自动变长"],"answer":[0],"explanation":"知识点：压脚压力对送料的影响。压脚压力过大会压紧缝料，使上下层送料不同步而产生错位起皱。面线张力由夹线器调节，不会因压脚压力自动变小。梭芯转动阻力与压脚压力无关。针距由送布凸轮偏心量决定，不会自动变长。","tier":"挑战"},{"id":84,"type":"single","stem":"某批绷缝机装配后出现缝速升高时断针频繁，低速时正常，最应先检查的环节是","options":["弯针与机针的配合相位","压脚底面粗糙度","梭芯绕线张力","台板减振垫厚度"],"answer":[0],"explanation":"知识点：高速断针的相位排查。高速时运动件惯性增大，弯针与机针配合相位偏差会暴露，应优先检查。压脚底面粗糙度主要影响送料阻力，不随速度突变。梭芯绕线张力影响线迹松紧，不直接导致断针。台板减振垫影响整机振动，不是断针首查项。","tier":"进阶"},{"id":85,"type":"multi","stem":"包缝机装配调试中，影响线迹收线不良的因素包括","options":["上下弯针勾线相位偏差","挑线杆过线孔毛刺","送布牙高度低于针板","压脚压力偏小","缝线张力盘夹线过松"],"answer":[0,1,4],"explanation":"知识点：包缝线迹收线的多因素分析。上下弯针勾线相位偏差会使线环交接不良，收线不匀。挑线杆过线孔毛刺会刮伤或阻滞缝线，影响收线。缝线张力盘夹线过松直接造成线迹松弛。送布牙高度低于针板主要影响送料，不直接决定收线。压脚压力偏小影响送料稳定性，不是收线不良的主因。","tier":"进阶"},{"id":86,"type":"single","stem":"平缝机面线在缝料下侧形成大量浮线且底线被拉入缝料，最应先检查的机构是","options":["梭皮螺钉的夹线压力是否过小","挑线杆的过线孔有无毛刺","针杆的上下间隙是否偏大","送布牙的高度是否过低"],"answer":[0],"explanation":"知识点是底面线张力平衡。正确项对：面线浮到下面说明底线张力过小，梭皮螺钉压不住底线，需先调大梭皮压力。挑线杆过线孔毛刺会断线，不造成浮线。针杆间隙偏大引起断针或跳针，不直接造成底线被拉入。送布牙过低影响送料不畅，不改变线迹张力关系。","tier":"进阶"},{"id":87,"type":"single","stem":"工业包缝机在缝制薄料时出现针迹边缘卷边，调整差动送布时应","options":["增大差动比使前牙送布量大于后牙","减小差动比使前后牙送布量相等","增大压脚压力并降低针杆高度","调快主轴转速并放松挑线簧"],"answer":[0],"explanation":"知识点是差动送布与卷边的关系。正确项对：薄料卷边需要伸展送布，加大差动比让前牙多送可把边缘拉开。减小差动比到相等会失去差动作用，卷边依旧。压脚压力和针杆高度与卷边成因无关。转速和挑线簧张力不改变送布差动效果。","tier":"基础"},{"id":88,"type":"single","stem":"装配工业缝纫机时，主轴上两个圆锥滚子轴承的预紧目的是","options":["消除轴向游隙以提高主轴旋转精度","降低轴承温升以延长润滑周期","增大径向载荷能力以防止轴弯曲","减少润滑油用量以降低运转阻力"],"answer":[0],"explanation":"知识点是轴承预紧的作用。正确项对：预紧消除轴向游隙，使主轴在高速下不窜动，保证勾线机构稳定。预紧会增加预载，通常使温升略升而非降低。预紧不改变径向额定载荷能力。预紧与润滑油用量无直接关系。","tier":"基础"},{"id":89,"type":"single","stem":"某平缝机在低速时线迹正常，高速时出现规律性跳针，最可能的原因是","options":["挑线簧弹力偏弱导致高速时收线不及时","梭尖磨损导致勾线深度不够","针杆连接螺钉松动造成针杆下滑","压脚底面粗糙造成送料阻滞"],"answer":[0],"explanation":"知识点是高速跳针的成因。正确项对：高速时挑线簧若弹力不足，线环形成不稳定，勾线时机错乱造成跳针。梭尖磨损在高低速都会跳针，不表现低速正常。针杆下滑会使针杆高度改变，低速也异常。压脚粗糙影响送料，不造成规律跳针。","tier":"进阶"},{"id":90,"type":"single","stem":"绷缝机在缝制弹性针织布时出现针洞，调整时应首先考虑","options":["更换小号圆头针并适当降低针杆高度","增大压脚压力使布面更平整","调大挑线簧张力使线迹更紧","提高差动比使送布更充分"],"answer":[0],"explanation":"知识点是针洞的预防。正确项对：针洞多因针号过大或针尖过尖刺断纱线，换小号圆头针并略降针杆可减少穿刺损伤。增大压脚压力会加剧布面拉伸，不利。挑线簧张力过大使缝线勒紧布面，也易成洞。差动比过大反而使布面变形，不是针对针洞的措施。","tier":"基础"},{"id":91,"type":"single","stem":"工业缝纫机装配中，机针与针板孔中心的同轴度超差会导致","options":["缝料被针板孔边缘刮破并频繁断针","梭尖勾线过早造成线迹浮松","送布牙与针板摩擦发出异响","挑线杆过线孔磨损加快"],"answer":[0],"explanation":"知识点是针与针板孔的配合。正确项对：针不在针板孔中心会蹭孔壁，刮破缝料并别断机针。梭尖勾线时机由旋梭位置决定，与针板孔同轴度无关。送布牙异响来自牙与针板平面间隙不当。挑线杆磨损与过线孔光洁度有关。","tier":"基础"},{"id":92,"type":"single","stem":"某平缝机梭心套装入旋梭后转动不灵活且有卡滞感，正确的处置是","options":["检查梭心套外圆与旋梭内圆的配合及有无异物","加大梭皮螺钉压力使底线更紧","更换更粗的底线以填满间隙","调低针杆高度改变勾线位置"],"answer":[0],"explanation":"知识点是梭心套配合。正确项对：卡滞说明梭心套与旋梭内圆配合过紧或有线头、毛刺，应检查清理并确认配合间隙。加大梭皮压力只影响出线阻力，不解决转动卡滞。换粗底线会使卡滞更严重。针杆高度与梭心套转动无关。","tier":"进阶"},{"id":93,"type":"single","stem":"装配缝纫机挑线机构时，挑线杆过线孔出现明显沟槽，正确的处理方式是","options":["更换挑线杆并检查过线孔圆滑度","用砂纸把沟槽打磨光滑后继续使用","把挑线簧张力调大以补偿沟槽","将过线孔位置旋转一个角度使用"],"answer":[0],"explanation":"知识点是过线零件的磨损处理。正确项对：过线孔沟槽会割伤缝线，必须更换新件并确认孔口圆滑。打磨会破坏孔口几何形状和镀层，仍会伤线。调大挑线簧张力不能消除沟槽对线的切割。旋转过线孔位置会改变挑线时机，且沟槽仍在。","tier":"进阶"},{"id":94,"type":"single","stem":"某服装厂一台平缝机在连续工作两小时后出现旋梭部位发热并伴有线迹变紧，现场最合理的下一步处置是","options":["停机检查旋梭供油是否畅通并清理油路","继续运行并调松挑线簧张力","加大梭皮螺钉压力使底线更紧","提高主轴转速使润滑油分布更均匀"],"answer":[0],"explanation":"知识点是旋梭发热与润滑。正确项对：发热多因供油不畅或缺油，应停机检查油路和油量，避免烧损旋梭。继续运行并调松挑线簧会掩盖问题并加剧磨损。加大梭皮压力与发热无关且使线迹更紧。提高转速会加剧发热，是错误处置。","tier":"挑战"},{"id":95,"type":"single","stem":"装配工业平缝机下轴时，轴套内壁应先涂一层薄油再推入轴，这一操作的主要作用是","options":["防止轴套压入时刮伤轴颈表面","提高轴套与轴颈的过盈配合紧度","降低轴套压入后轴颈的轴向窜动量","增强轴套在机壳孔内的防转摩擦力"],"answer":[0],"explanation":"知识点：轴套装配的预润滑作用。正确项：薄油膜可减小推入时的摩擦，避免轴颈表面被刮伤。错误项A：油膜会降低而非提高过盈配合的紧度；错误项B：轴向窜动量由定位结构决定，与涂油无关；错误项C：轴套防转靠紧配合或定位销，涂油不会增强其摩擦力。","tier":"基础"},{"id":96,"type":"single","stem":"调试高速包缝机时发现缝料边缘出现周期性跳针，针杆高度和机针型号均已确认正常，下一步应优先检查的部位是","options":["弯针与机针的配合相位和间距","压脚压力是否偏大导致送料阻滞","差动送料比是否与缝料弹性匹配","针板容针孔是否因磨损而变大"],"answer":[0],"explanation":"知识点：包缝机跳针的排查顺序。正确项：周期性跳针多与弯针和机针的配合相位、间距偏差有关，应优先核对。错误项A：压脚压力偏大主要造成送料不畅或起皱，不是周期性跳针的主因；错误项B：差动比影响线迹松紧和缝料拉伸，不直接导致周期性跳针；错误项C：容针孔磨损会影响断针或扎料，通常不表现为固定周期跳针。","tier":"挑战"},{"id":97,"type":"single","stem":"工业缝纫机旋梭供油量调试中，若供油量调得过大，最可能出现的现象是","options":["缝料针迹处出现油污且旋梭温升偏低","旋梭部位温升偏高并伴有异常噪音","梭尖勾线时出现规律性断线","送布牙与针板间隙变小导致卡料","梭壳内底线张力明显增大"],"answer":[0],"explanation":"知识点：旋梭供油量与运行状态的关系。正确项：供油过大时多余油会甩到缝料上形成油污，同时润滑充分使旋梭温升偏低。错误项A：温升偏高、异常噪音通常是供油不足或配合过紧的表现；错误项B：规律性断线多与勾线相位、梭尖磨损有关；错误项C：送布牙与针板间隙由装配位置决定，与供油量无关；错误项D：底线张力由梭壳弹簧片调节，供油量不影响其大小。","tier":"进阶"},{"id":98,"type":"single","stem":"某厂装配一批电脑平缝机，试缝时发现针距在低速下正常、高速时明显变短，以下排查思路中合理的是","options":["检查送布凸轮紧固螺钉是否在高速振动下松动","直接更换针距调节旋钮以排除刻度误差","把压脚压力调至最大以增加送布摩擦力","将机针换粗一号以增大穿刺力","降低缝纫速度至中速作为最终交付状态"],"answer":[0],"explanation":"知识点：高速针距变短的常见原因。正确项：高速时送布凸轮若紧固不良会打滑，导致实际送布量减小，应先检查紧固状态。错误项A：旋钮刻度误差在低速时也会表现，不能解释速度相关性；错误项B：压脚压力过大会增加阻力，可能使针距更短；错误项C：换粗针影响穿刺和线迹，不解决送布量问题；错误项D：降速交付属于掩盖故障，不是排查思路。","tier":"挑战"},{"id":99,"type":"single","stem":"装配绷缝机时，需要保证针杆下死点时弯针尖与机针中心线的相对位置，这一尺寸通常应控制的范围是","options":["弯针尖略高于机针针眼上缘约1至2毫米","弯针尖低于机针针眼下缘约3至4毫米","弯针尖与针眼上缘齐平且间隙为零","弯针尖高于针杆下端面约5至6毫米"],"answer":[0],"explanation":"知识点：绷缝机弯针与机针的配合位置。正确项：弯针尖应略高于机针针眼上缘约1至2毫米，才能可靠勾取线环。错误项A：低于针眼下缘会勾不到线环；错误项B：齐平且零间隙会造成碰针或勾线不稳；错误项C：以针杆下端面为基准不符合配合要求，且5至6毫米偏差过大。","tier":"进阶"},{"id":100,"type":"multi","stem":"装配调试工业缝纫机时，下列做法中有利于减少机器运转振动和噪音的有","options":["各运动部件装配前清洗并按规定加注润滑脂","机架与台板连接螺栓按对角顺序均匀拧紧","皮带张紧度调整到用手按压有明显下垂量","高速运转部件进行动平衡检查后再装机","为缩短装配时间省略部分定位销直接锁紧螺钉"],"answer":[0,1,3],"explanation":"知识点：装配工艺对振动和噪音的影响。正确项A：清洁和规范润滑可减小摩擦与冲击；正确项B：对角均匀拧紧可避免机架变形和松动；正确项D：动平衡检查能消除高速旋转件的不平衡激振。错误项C：皮带张紧度应有规定值，明显下垂说明过松，易打滑和抖动；错误项E：省略定位销会使部件相对位置失准，装配后振动和噪音反而增大。","tier":"挑战"},{"id":101,"type":"single","stem":"工业平缝机装配时，下轴与上轴的同步关系应通过哪个部件来保证","options":["竖轴传动齿轮的啮合位置","送布凸轮的紧固螺钉","针距调节旋钮的刻度","挑线杆的过线孔位置"],"answer":[0],"explanation":"知识点为平缝机上下轴同步传动。竖轴两端锥齿轮的啮合位置决定上下轴相位关系，装配时必须按对位标记啮合；送布凸轮只影响送布时序；针距旋钮调节送布量；挑线杆过线孔影响挑线量，均不决定上下轴同步。","tier":"基础"},{"id":102,"type":"single","stem":"旋梭与机针的配合中，当机针下降到最低点时，梭尖应位于机针中心线上方约多少毫米并开始勾线","options":["1.5～2.5","4.5～5.5","7.5～8.5","0.1～0.5"],"answer":[0],"explanation":"知识点为旋梭勾线时机。机针最低点时梭尖在针孔上方约1.5～2.5mm处开始勾线，才能稳定勾住线环；4.5mm以上梭尖过高会勾不住线环；7.5mm以上严重错位；0.1～0.5mm过低会撞针或跳针。","tier":"基础"},{"id":103,"type":"single","stem":"装配高速包缝机时，上下弯针的交叉间隙通常应调整为","options":["0.05～0.1mm","0.5～0.8mm","1.0～1.5mm","2.0～2.5mm"],"answer":[0],"explanation":"知识点为包缝机弯针配合间隙。上下弯针交叉处需保持约0.05～0.1mm微间隙，既能顺利交接缝线又不会相互刮擦；0.5mm以上间隙过大会漏线跳针；1mm以上无法正常交接；2mm以上完全失效。","tier":"基础"},{"id":104,"type":"single","stem":"某操作工在装配平缝机送布凸轮时，先拧紧凸轮螺钉再调整送布相位，结果缝纫时出现送布与挑线不同步，正确的装配顺序应是","options":["先按对位标记调好相位再拧紧螺钉","先拧紧螺钉再微调凸轮位置","先拆下挑线杆再装凸轮","先调针距旋钮再装凸轮"],"answer":[0],"explanation":"知识点为送布凸轮装配程序。送布凸轮必须先按对位标记确定相位再紧固，否则紧固后无法微调；先紧后调会因摩擦力锁死位置；拆挑线杆与送布相位无关；针距旋钮不改变相位。","tier":"进阶"},{"id":105,"type":"single","stem":"某车间一台平缝机在缝制薄料时线迹忽松忽紧，检查夹线器、旋梭均正常，最应进一步检查的部位是","options":["挑线杆过线孔及挑线簧的弹性","针板螺钉的紧固力矩","机头罩壳的密封条","电机皮带轮的直径"],"answer":[0],"explanation":"知识点为线迹不稳定的排查。夹线器和旋梭正常时，挑线杆过线孔磨损或挑线簧弹性变化会造成收线量波动；针板螺钉、罩壳密封条、皮带轮直径均不引起线迹忽松忽紧。","tier":"挑战"},{"id":106,"type":"single","stem":"工业平缝机装配时，针杆下轴套压入后出现针杆上下运动发涩，以下处置中最先应做的是","options":["用细砂纸修磨针杆外圆后重新装入轴套","拆下轴套检查内孔与针杆配合间隙并清理毛刺","向轴套内加注机油后继续装配试机","调整针杆曲柄位置改变针杆行程"],"answer":[1],"explanation":"考点是轴套与针杆配合发涩的排查顺序。装配发涩首先要拆检配合面和间隙，排除毛刺、异物或间隙过小，所以B对。A在未查明原因前修磨针杆会破坏配合精度。C加机油只能暂时掩盖问题，不能消除卡滞根源。D针杆行程由曲柄机构决定，与上下运动发涩无关。","tier":"进阶"},{"id":107,"type":"single","stem":"某平板缝纫机装配后试车，发现挑线杆在收线阶段不到位，导致线迹浮线，最可能的装配问题是","options":["挑线杆与针杆的同步相位装错","旋梭与机针的勾线时机装错","送布牙高度低于针板平面","压脚压力调得过小"],"answer":[0],"explanation":"考点是挑线机构相位对收线的影响。挑线杆收线不到位说明其运动相位与针杆不匹配，所以A对。B勾线时机错会造成跳线而非单纯浮线。C送布牙过低影响送料，不直接造成浮线。D压脚压力小影响布料压紧，通常表现为布料走动异常而非收线浮线。","tier":"挑战"},{"id":108,"type":"single","stem":"装配工业包缝机时，操作者发现上弯针与下弯针在交叉处相碰，正确的调整顺序是","options":["先调整弯针前后间隙再调整左右位置","先调整弯针左右位置再调整前后间隙","先调整弯针高度再调整弯针角度","先调整弯针角度再调整弯针高度"],"answer":[0],"explanation":"考点是弯针交叉相碰的调整顺序。弯针相碰通常先解决前后方向的间隙，再调左右交叉位置，所以A对。B顺序颠倒会导致左右调好后前后仍相碰。C、D高度和角度不是造成相碰的首要调整项，先调它们无法消除干涉。","tier":"挑战"},{"id":109,"type":"single","stem":"缝纫机装配完成后进行空运转试验，以下做法符合调试规范的是","options":["先低速运转观察各机构动作再逐步提速","直接以最高转速运转检查机器稳定性","拆下皮带后让电机单独高速空转","在无润滑油状态下先高速跑合再加油"],"answer":[0],"explanation":"考点是空运转试验的规范步骤。装配后应先低速观察各机构动作是否正常，再逐级提速，所以A对。B直接最高速容易造成未跑合机构损坏。C拆皮带单转电机考察的是电机而非整机装配质量。D无油高速跑合会加剧磨损，不符合调试规范。","tier":"基础"},{"id":110,"type":"single","stem":"装配高速平缝机时，旋梭与机针的配合要求中，正确的做法是","options":["机针回升到规定位置时旋梭尖到达机针中心线","机针下降到最低点时旋梭尖勾住面线","旋梭尖与机针间隙保持为零始终接触","机针上升全程旋梭尖都贴住机针"],"answer":[0],"explanation":"考点是旋梭勾线时机。机针回升到规定位置时旋梭尖应到达机针中心线并勾住线环，所以A对。B最低点时线环尚未形成，勾不住线。C旋梭尖与机针需保持微小间隙，零间隙会磨损机针。D全程贴住机针不现实且会断针。","tier":"挑战"},{"id":111,"type":"single","stem":"某缝纫机维修人员给机器更换新旋梭后，试车发现跳线，以下检查步骤中最应先做的是","options":["检查旋梭尖与机针的间隙和勾线时机","更换更粗的机针重新试车","把面线张力调到最大再试车","把旋梭供油量调大后试车"],"answer":[0],"explanation":"考点是更换旋梭后跳线的排查。换旋梭后跳线首先查旋梭尖与机针间隙及勾线时机是否装准，所以A对。B换粗针不解决勾线时机问题。C张力调大可能加剧跳线或断线。D供油量影响磨损和温度，与勾线跳线无直接关系。","tier":"挑战"},{"id":112,"type":"single","stem":"装配缝纫机送布机构时，送布牙上升露出针板平面的高度通常应控制在","options":["0.5至0.8毫米","1.5至2.0毫米","3.0至3.5毫米","4.0至4.5毫米"],"answer":[0],"explanation":"考点是送布牙露出针板的高度标准。常规装配中送布牙上升露出针板约0.5至0.8毫米，所以A对。B过高会刮伤布料并造成送料不均。C、D远高于正常范围，会顶起布料甚至卡布。","tier":"基础"},{"id":113,"type":"single","stem":"装配调试某厚料缝纫机时，操作者发现机针在穿过厚料后回升时线环偏小，正确的调试思路是","options":["适当增大机针回升量并检查针杆高度","把旋梭尖向机针方向靠近直至接触","把面线张力调到最小让线环变大","降低送布牙高度减少布料阻力"],"answer":[0],"explanation":"考点是厚料下线环偏小的调整。厚料时机针回升量不足会使线环偏小，应适当增大回升量并核对针杆高度，所以A对。B旋梭尖接触机针会磨损断针。C张力极小会使线迹松散，不能增大线环。D送布牙高度与线环大小无直接关系。","tier":"挑战"},{"id":114,"type":"single","stem":"某缝纫机装配完成后，操作者发现缝料背面出现毛巾状线团，检查旋梭与机针配合正常，以下最可能的调整方向是","options":["适当增大挑线杆收线量并核对挑线相位","把旋梭勾线时间再调早一点","把送布牙升高使送料更充分","把针杆下轴套间隙调大"],"answer":[0],"explanation":"考点是背面毛巾状线团的成因。该现象多为面线收线不足，应增大挑线杆收线量并核对挑线相位，所以A对。B勾线调早会加剧跳线或线团。C送布牙高度与收线无关。D轴套间隙调大会引起针杆晃动，不能解决收线问题。","tier":"挑战"},{"id":115,"type":"single","stem":"工业平缝机针杆高度调整时，应以下列哪个部件作为基准来确定针杆下死点位置","options":["针杆下端面与针板平面的距离","机针针尖与旋梭梭尖的配合位置","压脚底面与针板平面的间隙","挑线杆最高点与针杆上端面的距离"],"answer":[1],"explanation":"知识点是平缝机针杆高度的基准确定。平缝机针杆高度以机针针尖与旋梭梭尖的配合位置为基准，保证梭尖在针孔上方约1.5mm处勾线；针杆下端面与针板距离随机型不同，不是基准；压脚底面间隙属于压脚调整，与针杆高度无关；挑线杆位置由挑线机构决定，不用于确定针杆高度。","tier":"进阶"},{"id":116,"type":"single","stem":"调整平缝机旋梭与机针的间隙时，若旋梭尖与机针配合过紧，缝纫中最先出现的异常现象通常是","options":["机针弯曲或针尖磨钝加快","旋梭梭尖磨损加剧并断线","压脚压力不足走布打滑","挑线弹簧张力变小跳针"],"answer":[1],"explanation":"知识点是旋梭与机针间隙的配合影响。旋梭尖与机针间隙过紧会造成梭尖刮针，使梭尖磨损加剧并频繁断线；机针弯曲多因夹线过紧或送布牙顶针造成，不是最先表现；压脚压力不足属于压脚调整问题；挑线弹簧张力变化属于挑线机构调整，与旋梭间隙无直接关系。","tier":"进阶"},{"id":117,"type":"single","stem":"平缝机送布牙高度调整时，标准状态应使送布牙齿尖高出针板平面多少","options":["与针板平面平齐","约0.5mm","约1.0mm","约3.0mm"],"answer":[2],"explanation":"知识点是送布牙高度标准。平缝机送布牙齿尖一般高出针板平面约1.0mm，既能有效送布又不刮伤面料；与针板平齐会送布无力；0.5mm偏低易打滑；3.0mm过高会顶起面料造成跳针和起皱。","tier":"基础"},{"id":118,"type":"single","stem":"工业包缝机在缝制薄料时出现针迹忽密忽疏，应优先检查下列哪个部位","options":["压脚底面是否磨损起槽","主轴上同步带的张紧程度","送布牙与压脚的压力配合","针杆是否装反方向"],"answer":[2],"explanation":"知识点是包缝机针迹不匀的排查顺序。薄料针迹忽密忽疏最常见原因是送布牙与压脚压力配合不当，压力过小面料打滑造成针迹不匀；压脚底面磨损影响的是压痕而非针距；同步带张紧影响整体同步但不直接造成忽密忽疏；针杆装反会导致无法正常勾线，不会表现为针距变化。","tier":"进阶"},{"id":119,"type":"single","stem":"装配工业平缝机挑线机构时，挑线杆在最高位置应使挑线量满足下列哪项要求","options":["与最低位置挑线量相等","略小于最低位置挑线量","大于最低位置挑线量以收线","由夹线器张力单独决定"],"answer":[2],"explanation":"知识点是挑线机构的收线原理。挑线杆在最高位置时挑线量应大于最低位置，以完成收线动作形成线迹；相等无法形成收线；略小则无法收紧线环；夹线器张力影响线张力大小，但不能改变挑线杆的挑线量。","tier":"进阶"},{"id":120,"type":"single","stem":"装配工业缝纫机时，主轴上各运动件的轴向间隙应控制在什么状态","options":["留有0.5mm以上自由间隙","无间隙且能灵活转动","有轻微轴向窜动即可","按轴承型号不同允许任意间隙"],"answer":[1],"explanation":"知识点是主轴装配的间隙要求。主轴各运动件装配后应无间隙且能灵活转动，避免轴向窜动引起噪声和磨损；留0.5mm以上自由间隙会产生冲击；轻微轴向窜动仍会造成振动；间隙不能任意，必须按装配要求控制。","tier":"基础"},{"id":121,"type":"single","stem":"工业缝纫机调试中，机针与旋梭的勾线时机应调整在机针从下死点回升多少距离时梭尖到达针孔上方","options":["1.0mm左右","2.2mm左右","5.0mm左右","8.0mm左右"],"answer":[1],"explanation":"知识点是勾线时机的标准。平缝机机针从下死点回升约2.2mm时，旋梭梭尖应到达针孔上方约1.5mm处完成勾线；1.0mm回升不足，线环未形成；5.0mm和8.0mm回升过大，线环已变形或消失，均无法正常勾线。","tier":"基础"},{"id":122,"type":"single","stem":"某台平缝机在缝制化纤薄料时频繁断线，检查发现夹线器张力正常、机针无弯曲，下一步应优先检查的是","options":["旋梭梭尖是否有毛刺或磨损","送布牙高度是否过低","压脚底面是否粗糙","挑线弹簧是否过硬"],"answer":[0],"explanation":"知识点是断线故障的排查逻辑。夹线器张力和机针均正常时，化纤薄料断线多因旋梭梭尖有毛刺或磨损割断缝线，应优先检查旋梭；送布牙过低会造成送布不良而非断线；压脚底面粗糙影响面料滑动；挑线弹簧过硬影响线张力波动，但通常表现为浮线而非断线。","tier":"挑战"},{"id":123,"type":"single","stem":"装配工业缝纫机时，各油路油管的走向应遵循的原则是","options":["油管尽量贴近运动件以便润滑","油管应远离高温件并固定牢靠","油管可随意弯曲以避开螺钉","油管接头处允许轻微渗油以利排气"],"answer":[1],"explanation":"知识点是油路装配原则。油管应远离高温件并固定牢靠，防止受热老化或振动磨损；贴近运动件会被摩擦损坏；随意弯曲会造成油路堵塞或折扁；接头渗油属于装配缺陷，会造成漏油和供油不足。","tier":"基础"},{"id":124,"type":"single","stem":"某缝制设备维修人员在调试包缝机时，发现上下弯针配合不良导致跳针，正确的调整顺序应是","options":["先调上弯针高度再调下弯针前后位置","先调下弯针高度再调上弯针前后位置","先调针杆高度再调弯针配合","先调压脚压力再调弯针配合"],"answer":[2],"explanation":"知识点是包缝机弯针配合的调整顺序。弯针配合必须在针杆高度正确的前提下进行，因此应先调针杆高度再调弯针配合；先调上下弯针而不校针杆，弯针位置失去基准；压脚压力与弯针配合无直接关系。","tier":"挑战"},{"id":125,"type":"single","stem":"工业平缝机装配后首次通电试机，手轮转动但机针不上下运动，最可能的原因是","options":["上轴与下轴同步带未张紧导致打滑","针杆连接柱紧固螺钉未锁紧在针杆上","挑线杆曲柄与上轴连接螺钉松动","送布牙偏心轮相位装反"],"answer":[1],"explanation":"知识点：针杆传动链。针杆连接柱螺钉未锁紧时，针杆曲柄的摆动无法传到针杆，表现为手轮转而针不动。上轴下轴带打滑会导致机针与旋梭不同步而非针完全不动；挑线杆曲柄松动影响挑线量而非针杆运动；送布牙偏心轮装反影响送布动作。","tier":"进阶"},{"id":126,"type":"single","stem":"调试平缝机旋梭时，机针从最低点回升到旋梭勾线尖对准针孔上缘，此时针杆回升量通常应调整在","options":["0.5~0.8mm","1.8~2.2mm","3.5~4.0mm","5.0~5.5mm"],"answer":[1],"explanation":"知识点：旋梭勾线时机。平缝机标准勾线时机为针杆从下死点回升约1.8~2.2mm，此时旋梭尖正好到达针孔上缘并留有0.05~0.1mm间隙。0.5~0.8mm回升量过小，旋梭尖易扎针孔下方；3.5mm以上回升量过大，线环已变形扭结，易跳针断线。","tier":"挑战"},{"id":127,"type":"single","stem":"包缝机装配后试缝，发现缝料边缘出现规律性跳针，且跳针位置随转速升高而增多，应优先检查","options":["上下弯针的勾线距与间隙配合","压脚压力是否偏大","送布牙高度是否超出针板","差动比是否设置过小"],"answer":[0],"explanation":"知识点：包缝机弯针配合。规律性跳针且随转速加剧，典型原因是上下弯针勾线距或间隙不当，转速高时线环变形更明显。压脚压力偏大会造成送料不畅而非规律跳针；送布牙过高会造成缝料起皱；差动比过小影响缝料拉伸，不产生规律跳针。","tier":"挑战"},{"id":128,"type":"single","stem":"某厂装配的平缝机在缝制薄料时线迹正常，换厚料后出现断针，排除机针质量问题后应重点调整","options":["增大挑线簧行程以补偿用线量","调低针杆高度并相应调晚勾线时机","减小压脚压力使缝料自由通过","降低送布牙高度避免顶针"],"answer":[1],"explanation":"知识点：厚料缝纫时机针与旋梭配合。厚料时缝料抬升使针杆实际工作位置变化，若针杆过高、勾线过早，机针会与旋梭或送布牙干涉断针，应适当降低针杆并调晚勾线。增大挑线簧行程解决的是收线问题；减小压脚压力会使厚料送不动；降低送布牙高度反而不利于厚料输送。","tier":"进阶"},{"id":129,"type":"single","stem":"绷缝机装配后出现缝料背面线迹浮线、正面线迹正常的现象，应首先调整","options":["增大弯针挑线凸轮的挑线量","减小绷缝线张力并增大底线张力","调换上下弯针的安装顺序","降低压脚高度使缝料贴紧针板"],"answer":[0],"explanation":"知识点：绷缝机线迹形成与张力分配。背面浮线说明绷缝线（弯针线）收线不足，应增大弯针挑线凸轮挑线量或调整挑线凸轮相位。单纯减小绷缝线张力会使正面也浮线；调换弯针顺序会破坏勾线配合；降低压脚高度与浮线无直接因果关系。","tier":"进阶"},{"id":130,"type":"single","stem":"工业缝纫机装配中，用于保证机头与底座油盘结合面不漏油的正确做法是","options":["结合面涂满厚层密封胶后立即紧固","结合面清洁后涂适量密封胶并按对角顺序紧固","结合面垫入普通纸垫后直接紧固","结合面不涂胶靠紧固螺钉压紧即可"],"answer":[1],"explanation":"知识点：结合面密封装配工艺。正确做法是清洁结合面、涂适量密封胶、按对角顺序均匀紧固，保证胶层均匀无间隙。涂厚层胶会挤出到油道内造成堵塞；普通纸垫耐油性差易渗漏；不涂胶仅靠压紧难以保证微观密封。","tier":"挑战"},{"id":131,"type":"single","stem":"平缝机调试时，挑线杆供线量与旋梭勾线时机配合不当，最容易出现的故障是","options":["缝料起皱","线迹忽松忽紧","机针发热","送布牙磨损"],"answer":[1],"explanation":"知识点：挑线杆与勾线时机配合。挑线杆收放线量与勾线时机必须匹配，配合不当会使每次成缝用线量不一致，表现为线迹忽松忽紧。缝料起皱多与压脚压力、送布牙有关；机针发热与转速、针号有关；送布牙磨损属机械磨损。","tier":"基础"},{"id":132,"type":"single","stem":"装配某型号平缝机时，说明书要求旋梭与机针的间隙为0.05~0.1mm，现场无塞尺，下列判断方法中最合理的是","options":["目视观察旋梭尖刚好不碰机针即可","用一张普通A4纸插入间隙感觉轻微阻力","用手转动旋梭感觉有轻微摩擦声","用机针针柄插入间隙判断松紧"],"answer":[1],"explanation":"知识点：微小间隙的现场判断。普通A4纸厚度约0.1mm，插入感觉轻微阻力可近似判断0.1mm以内间隙，是现场常用替代法。目视无法分辨0.05mm差异；有摩擦声说明已接触；针柄直径远大于间隙无法插入。","tier":"挑战"},{"id":133,"type":"single","stem":"在装配平缝机送布机构时，送布牙在针板槽中前后运动但左右有轻微晃动，正确的处理方式是","options":["更换送布牙并调整送布牙架滑块间隙","加厚针板使送布牙被槽壁限位","调高送布牙露出针板的高度","增大送布凸轮偏心量补偿晃动"],"answer":[0],"explanation":"知识点：送布机构配合精度。送布牙左右晃动说明牙架滑块或送布牙安装间隙过大，应更换磨损件并调整间隙。加厚针板不能消除晃动且影响送布；调高送布牙与左右晃动无关；增大偏心量只改变送布距离。","tier":"进阶"},{"id":134,"type":"multi","stem":"工业缝纫机装配完成后进行精度检验，下列属于必检项目的操作有","options":["检查机针与旋梭勾线间隙","测量上轴轴向窜动量","检查压脚底面与针板的平行度","检查电机铭牌上的生产日期","测量机壳表面油漆光泽度"],"answer":[0,1,2],"explanation":"知识点：装配精度检验项目。勾线间隙、上轴轴向窜动、压脚与针板平行度均直接影响缝纫性能，属必检项目。电机生产日期与装配精度无关；油漆光泽度属外观要求，不是精度检验必检项。","tier":"进阶"},{"id":135,"type":"single","stem":"工业平缝机装配时，针杆下端面与针板平面的距离在针杆处于下死点时通常应调整到","options":["9至11毫米","14至16毫米","19至21毫米","24至26毫米"],"answer":[0],"explanation":"知识点是平缝机针杆高度基准。针杆下死点时下端面到针板平面保持约9至11毫米，才能保证机针孔与旋梭钩线时机配合。14至16毫米会使钩线过迟，19至21毫米与24至26毫米均超出正常范围，会导致跳针或断针。","tier":"基础"},{"id":136,"type":"single","stem":"装配旋梭时，旋梭尖与机针之间的间隙应调整到","options":["0.05至0.10毫米","0.30至0.50毫米","0.80至1.00毫米","1.20至1.50毫米"],"answer":[0],"explanation":"知识点是旋梭与机针的配合间隙。标准值约0.05至0.10毫米，既能顺利钩线又不会撞针。0.30至0.50毫米间隙偏大容易跳针，0.80至1.00毫米和1.20至1.50毫米间隙过大，旋梭尖无法可靠钩住线环。","tier":"基础"},{"id":137,"type":"single","stem":"平缝机挑线杆供线量调整过大时，缝纫过程中最容易出现的现象是","options":["线迹浮线松弛","缝线频繁崩断","送布牙刮伤面料","压脚压力自动增大"],"answer":[0],"explanation":"知识点是挑线杆供线量与线迹张力的关系。供线量过大则每次收线不足，线迹松弛浮线。送布牙刮伤面料与供线量无直接关系，压脚压力由调压螺钉控制不会自动增大，缝线崩断通常是供线量过小或张力过大所致。","tier":"基础"},{"id":138,"type":"single","stem":"装配送布凸轮时，若送布凸轮与下轴的紧固螺钉未拧紧产生相对滑动，缝纫时最直接的表现是","options":["针距长度不稳定","压脚不能抬起","旋梭供油中断","机针温度升高"],"answer":[0],"explanation":"知识点是送布凸轮与下轴的定位关系。凸轮滑动会改变送布偏心量，导致针距忽长忽短。压脚抬起由压脚扳手控制，旋梭供油由油路控制，机针温升与转速和摩擦有关，均与凸轮滑动无直接因果。","tier":"基础"},{"id":139,"type":"single","stem":"工业缝纫机装配完成后进行空载试运转，通常要求连续运转时间不少于","options":["1分钟","5分钟","30分钟","4小时"],"answer":[2],"explanation":"知识点是装配后空载试运转规范。一般要求连续空载运转不少于30分钟，以观察温升、噪声和运转平稳性。1分钟和5分钟过短无法充分暴露问题，4小时超出常规出厂试运转时长。","tier":"基础"},{"id":140,"type":"single","stem":"平缝机压脚压力调整螺钉顺时针旋入时，压脚压力与送布效果的变化是","options":["压力增大，送布力增大","压力增大，送布力减小","压力减小，送布力增大","压力减小，送布力不变"],"answer":[0],"explanation":"知识点是压脚压力调节方向。顺时针旋入调压螺钉压缩弹簧，压力增大，压脚对缝料的握持力增大，送布力随之增大。其余选项方向或因果关系错误。","tier":"进阶"},{"id":141,"type":"single","stem":"旋梭供油量调试时，若油量调节螺钉旋入过深，最可能出现的后果是","options":["旋梭润滑不足发热磨损","缝料被油污污染","梭壳无法装入梭床","机针无法穿过针板孔"],"answer":[0],"explanation":"知识点是旋梭油量调节方向。旋入过深减小油路开度，供油减少，旋梭润滑不足而发热磨损。缝料油污是供油过大所致，梭壳装入与油量螺钉无关，机针穿孔与针板孔对位有关。","tier":"进阶"},{"id":142,"type":"single","stem":"某工位装配平缝机后试缝，发现线迹背面出现一个个小线圈浮起，正面线迹正常，首先应检查","options":["梭皮压簧压力是否过小","挑线杆供线量是否过大","送布牙是否过低","机头油量是否过大"],"answer":[0],"explanation":"知识点是线迹浮线的判断。背面浮小线圈说明底线张力不足，梭皮压簧压力过小是常见原因。挑线杆供线量过大会使正面也松弛，送布牙过低影响送布，机头油量过大与线迹浮线无直接关系。","tier":"挑战"},{"id":143,"type":"single","stem":"装配双针机时，两根机针高度不一致会导致","options":["一侧线迹跳针或断线","针距整体变长","压脚无法抬起","梭床油量增大"],"answer":[0],"explanation":"知识点是双针机两针高度一致性要求。两针高度不一致会使其中一针与旋梭钩线时机错位，造成一侧跳针或断线。针距由送布机构决定，压脚抬起由扳手控制，梭床油量由油路调节，均与此无关。","tier":"基础"},{"id":144,"type":"single","stem":"某维修工在调试绷缝机时，为消除跳针把弯针与机针的间隙调得比标准值更小，试缝后出现弯针尖碰撞机针，正确的下一步处置是","options":["恢复弯针与机针标准间隙并重新对针","继续减小间隙直至跳针消失","只更换新弯针不调间隙","提高缝纫速度观察是否改善"],"answer":[0],"explanation":"知识点是弯针与机针间隙过小的后果。间隙小于标准值会导致弯针尖撞针，正确处置是恢复标准间隙并重新对针。继续减小间隙会加重碰撞，只换弯针不调间隙不能解决对位问题，提高速度会加剧碰撞。","tier":"进阶"},{"id":145,"type":"single","stem":"工业平缝机装配时，针杆下端面到针板上平面的距离（针杆最低位）通常应调整在什么范围","options":["9至11毫米","12至14毫米","15至17毫米","18至20毫米"],"answer":[0],"explanation":"知识点：平缝机针杆高度基准。正确项对：针杆最低位距针板平面约9至11毫米，可保证梭尖勾线时机与线环大小。12至14毫米偏大会导致线环过大、勾线不稳。15至17毫米会使挑线杆供线时机错乱。18至20毫米属明显超出常规调整范围，挑线量无法补偿。","tier":"基础"},{"id":146,"type":"single","stem":"装配旋梭时，梭尖与机针中心线在针杆最低位时的前后间隙，常规调整值应为","options":["0.05至0.1毫米","0.1至0.2毫米","0.3至0.5毫米","0.8至1.0毫米"],"answer":[1],"explanation":"知识点：旋梭勾线间隙。正确项对：梭尖与针中心线间隙0.1至0.2毫米，过大易跳针，过小会碰针。0.05至0.1毫米偏小，易造成梭尖碰针断针。0.3至0.5毫米偏大，线环易从梭尖滑脱形成跳针。0.8至1.0毫米间隙过大，梭尖几乎无法可靠勾住线环。","tier":"基础"},{"id":147,"type":"single","stem":"装配挑线杆组件时，挑线杆供线量不足，缝纫中常出现的现象是","options":["线迹忽紧忽松并伴随断线","缝料被推向前方起皱","梭芯绕线不均匀","压脚压力自动变大"],"answer":[0],"explanation":"知识点：挑线杆供线与收线作用。正确项对：供线量不足时线环形成与收线不匹配，造成线迹松紧波动并易断线。缝料起皱多与送布牙与压脚配合有关。梭芯绕线不均属绕线器调整问题。压脚压力由调压螺钉决定，不会因挑线杆变化而自动变大。","tier":"基础"},{"id":148,"type":"single","stem":"装配平缝机送布牙时，送布牙上升到最高位应高出针板上平面约","options":["0.2至0.4毫米","0.6至0.9毫米","1.2至1.5毫米","2.0至2.5毫米"],"answer":[1],"explanation":"知识点：送布牙高度标准。正确项对：送布牙最高位高出针板0.6至0.9毫米，可保证有效送布又不刮伤缝料。0.2至0.4毫米偏低，薄料易打滑。1.2至1.5毫米偏高，厚料起皱且噪音大。2.0至2.5毫米过高，会严重刮料并顶起压脚。","tier":"基础"},{"id":149,"type":"single","stem":"装配平缝机压脚时，压脚底面与针板上平面的贴合状态应满足","options":["压脚放下后底面与针板平行且轻触","压脚前端略高于针板后端","压脚后端略高于针板前端","压脚底面与针板保持1毫米间隙"],"answer":[0],"explanation":"知识点：压脚装配基准。正确项对：压脚放下后应与针板平行并轻触，保证压料均匀。前端略高会使缝料前送时上抬，线迹不稳。后端略高会造成缝料后退受阻、起皱。保留1毫米间隙则压不住料，薄料会跳动。","tier":"基础"},{"id":150,"type":"multi","stem":"平缝机装配后试缝出现跳针，下列属于可能原因的有","options":["机针安装方向装反","旋梭勾线时间过早或过晚","针杆高度调整不当","压脚压力调得过大","梭芯绕线量偏少"],"answer":[0,1,2],"explanation":"知识点：跳针故障多因素分析。正确项对：机针方向装反使线环偏移；旋梭勾线时机错误会错过线环；针杆高度不当使线环大小不合适，三者均可致跳针。压脚压力过大主要造成送料不畅或起皱，不是跳针直接原因。梭芯绕线量偏少影响连续缝纫，不直接造成跳针。","tier":"进阶"},{"id":151,"type":"single","stem":"工业平缝机装配时，针杆下端面与针板平面的距离应通过何种操作来保证","options":["调整针杆高低位置后锁紧针杆连接块","改变针板厚度规格来凑合间隙","松开送布牙座螺钉后移动牙架","旋转挑线杆曲柄改变行程"],"answer":[0],"explanation":"知识点是针杆高度基准的建立。针杆高度由针杆连接块在针杆上的位置决定，调好后锁紧即可保证针板平面到针杆下端面的距离，故A正确；针板厚度是固定规格，靠换针板凑间隙会破坏其他配合关系，B错；送布牙座位置影响送布量而不影响针杆高度，C错；挑线杆曲柄决定挑线时序，与针杆高度无关，D错。","tier":"进阶"},{"id":152,"type":"single","stem":"旋梭与机针的配合时序中，机针从下极限位置回升多少时旋梭尖应到达机针中心线","options":["回升1.8～2.2mm","回升0.2～0.5mm","回升4.5～5.0mm","回升3.0～3.5mm"],"answer":[0],"explanation":"知识点是旋梭勾线时序。机针下极限回升约1.8～2.2mm时旋梭尖到达针中心并进入针孔上方，才能稳定勾住线环，故A正确；回升0.2～0.5mm时机针几乎未上升，线环尚未形成，B错；回升4.5～5.0mm时机针已升得过高，线环易脱出旋梭尖，C错；回升3.0～3.5mm时机针回升过多，勾线时机偏晚，D错。","tier":"进阶"},{"id":153,"type":"single","stem":"装配平缝机送布机构时，送布牙上升到最高位置应高出针板上平面多少","options":["0.8～1.0mm","0.1～0.2mm","2.5～3.0mm","1.8～2.0mm"],"answer":[0],"explanation":"知识点是送布牙高度的标准值。送布牙最高时高出针板平面约0.8～1.0mm，既能有效送料又不刮伤面料，故A正确；0.1～0.2mm送布牙几乎露不出针板，送料无力打滑，B错；2.5～3.0mm过高会顶起压脚、面料起皱，C错；1.8～2.0mm偏高，薄料易被顶出压痕，D错。","tier":"基础"},{"id":154,"type":"single","stem":"平缝机压脚压力调整过大时，缝纫薄料最可能出现的现象是","options":["面料被压脚压出齿痕且送料发涩","线迹变密且针距变小","挑线杆供线量明显增多","旋梭供油量自动加大"],"answer":[0],"explanation":"知识点是压脚压力对缝料的影响。压力过大使压脚紧压薄料，送布牙痕明显、送料阻力增大，故A正确；针距由送布机构决定，压力不改变针距，B错；挑线杆供线量由挑线凸轮决定，与压脚压力无关，C错；旋梭供油由油路和油量调节螺钉控制，与压脚压力无联动，D错。","tier":"基础"},{"id":155,"type":"single","stem":"重机DDL-8700类平缝机装配后试车，发现机器运转时声音异常沉闷且机头温度偏高，最可能的装配原因是","options":["主轴轴向间隙过小或轴承预紧过度","挑线杆弹簧弹力偏弱","针距调节盘刻度未归零","绕线器离合轮间隙偏大"],"answer":[0],"explanation":"知识点是主轴装配间隙与运转温升的关系。轴向间隙过小或轴承预紧过度会使摩擦阻力增大、温升异常，故A正确；挑线杆弹簧只影响挑线力，不会导致机头温升，B错；针距调节盘刻度影响针距大小，与温升无关，C错；绕线器离合轮只在绕线时起作用，不影响主轴温升，D错。","tier":"挑战"},{"id":156,"type":"single","stem":"绷缝机调试时，要求前后弯针的交叉间隙以及弯针与机针的间隙通常应控制在","options":["0.05～0.10mm","0.5～0.8mm","1.0～1.5mm","0.3～0.4mm"],"answer":[0],"explanation":"知识点是绷缝机弯针配合间隙。前后弯针交叉及弯针与机针间隙过大会漏线、过小会撞针，标准约0.05～0.10mm，故A正确；0.5～0.8mm间隙过大，线环交接不可靠，B错；1.0～1.5mm会直接漏勾，C错；0.3～0.4mm偏大，高速时仍易跳针，D错。","tier":"基础"},{"id":157,"type":"single","stem":"维修工在调试一台包缝机时，发现上弯针勾线正常但下弯针频繁漏线，正确的下一步处置是","options":["检查下弯针尖磨损及与机针的勾线间隙","加大压脚压力使缝料贴紧针板","调高送布牙使送料更顺畅","更换更粗的缝线以提高强度"],"answer":[0],"explanation":"知识点是包缝机单侧弯针漏线的定位。下弯针漏线应先查其针尖磨损和与机针的勾线间隙，故A正确；压脚压力影响送料，不解决弯针漏线，B错；送布牙高度只影响送料，与弯针勾线无关，C错；更换粗线可能使线环更难形成，反而加剧漏线，D错。","tier":"挑战"},{"id":158,"type":"single","stem":"装配工业缝纫机时，关于油路系统的检查，下列说法中符合装配要求的是","options":["油泵转子与泵体间隙应符合规定且回油畅通","油泵转子可任意方向装入泵体","油窗无油时可直接开机再补油","油管接头允许轻微渗油以利润滑"],"answer":[0],"explanation":"知识点是油路装配要求。油泵转子与泵体间隙需符合规定并保证回油畅通，故A正确；转子有方向要求，任意装入会导致供油异常，B错；油窗无油时开机可能烧轴，应先加油，C错；油管接头渗油会造成供油不足和污染，必须密封，D错。","tier":"进阶"},{"id":159,"type":"multi","stem":"平缝机装配完成后进行运转检查，下列哪些现象属于必须停机重新调整的装配缺陷","options":["手转主轴有明显卡滞或异响","针杆上下运动时与压脚杆有干涉","机器运转时机头温升在允许范围内","缝料线迹正面均匀背面略松","旋梭供油正常且油窗回油连续"],"answer":[0,1],"explanation":"知识点是装配验收的缺陷判定。手转主轴卡滞或异响说明配合过紧或零件干涉，必须停机重调，A正确；针杆与压脚杆干涉会造成撞件和断针，必须排除，B正确；机头温升在允许范围内属正常，C不选；正面均匀背面略松可通过微调张力解决，不属必须停机的装配缺陷，D不选；旋梭供油正常回油连续是合格状态，E不选。","tier":"挑战"},{"id":160,"type":"single","stem":"工业平缝机装配时，针杆下端面到针板平面的距离调整不当，最可能直接引起的问题是","options":["缝料起皱且线迹浮线","机针与旋梭尖相撞断针","压脚压力不足布料打滑","挑线杆供线量突然增大"],"answer":[1],"explanation":"针杆高低决定机针与旋梭的配合时机，位置过低会使机针下探过深与旋梭尖相撞断针。缝料起皱多与送布牙、压脚、线张力相关；压脚压力不足由压脚调压螺钉决定；挑线杆供线量由挑线凸轮相位决定，均与针杆高度无直接因果。","tier":"进阶"},{"id":161,"type":"single","stem":"调试工业平缝机旋梭时，旋梭尖到达机针中心线的正确时机是","options":["机针上升到最高点时","机针从下死点回升2至3毫米时","机针下降到接近针板时","挑线杆处于最低位置时"],"answer":[1],"explanation":"旋梭勾线时机应在机针从下死点回升2至3毫米、针眼上方形成线环时，此时旋梭尖正好到达机针中心线。机针最高点时线环已收缩无法勾取；机针接近针板时尚未形成线环；挑线杆最低位置与勾线时机无对应关系。","tier":"基础"},{"id":162,"type":"single","stem":"装配工业缝纫机送布牙时，送布牙齿面高出针板平面的常规调整范围是","options":["0.2至0.4毫米","0.8至1.0毫米","1.5至2.0毫米","2.5至3.0毫米"],"answer":[1],"explanation":"送布牙齿面一般高出针板平面0.8至1.0毫米，既能有效送布又不刮伤缝料。0.2至0.4毫米过低易打滑不走布；1.5至2.0毫米和2.5至3.0毫米过高会刮伤缝料并造成送布不均。","tier":"基础"},{"id":163,"type":"single","stem":"工业平缝机出现线迹浮线、底面线交织点偏向缝料下方的现象，最应先检查的部件是","options":["旋梭尖与机针的间隙","夹线器主张力调节","送布牙的齿面高度","针杆的上下位置"],"answer":[1],"explanation":"底面线交织点位置主要由上下线张力平衡决定，交织点偏下说明面线张力偏小或底线张力偏大，应首先检查夹线器主张力。旋梭间隙影响勾线不断线；送布牙高度影响送布；针杆位置影响勾线时机，均不直接决定交织点上下位置。","tier":"进阶"},{"id":164,"type":"single","stem":"装配包缝机时，上下弯针的交叉间隙调整不当，最容易出现的故障是","options":["线迹密度不均匀","弯针相互碰撞或跳针","压脚抬升高度不够","缝料边缘被切刀切斜"],"answer":[1],"explanation":"上下弯针在交叉运动时需保持0.05至0.1毫米间隙，间隙过大跳针、过小相互碰撞。线迹密度由送布机构决定；压脚抬升由抬压脚机构决定；切刀切斜由切刀对中决定，均与弯针交叉间隙无关。","tier":"进阶"},{"id":165,"type":"single","stem":"调试工业缝纫机挑线杆时，挑线杆供线量不足最可能造成的现象是","options":["线迹出现浮线","缝料起皱或断线","缝料边缘被切斜","压脚无法抬起"],"answer":[1],"explanation":"挑线杆供线量不足会使线环形成不良、收线过紧，导致缝料起皱或断线。浮线多因张力过小；切斜由切刀对中决定；压脚无法抬起由抬压脚机构决定，均与挑线杆供线量无关。","tier":"基础"},{"id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；机针发热多与机针钝、转速高、缝料厚有关；压脚抬升高度由压脚提升机构调整，与旋梭间隙无关。","tier":"进阶"},{"id":184,"type":"single","stem":"调试包缝机时，发现上下弯针在交叉处相碰，下列调整顺序中最合理的是","options":["先调上弯针高度再调下弯针前后位置","先调下弯针高度再调上弯针前后位置","先调压脚压力再调弯针交叉量","先调送布牙高度再调弯针交叉量"],"answer":[0],"explanation":"知识点是包缝机弯针配合的调整顺序。一般应先确定上弯针高度，再调整下弯针的前后位置使其在交叉处留有间隙，所以正确项是先调上弯针高度再调下弯针前后位置；先调下弯针高度会破坏已定的配合基准；压脚压力与弯针交叉无关；送布牙高度影响送布量而非弯针交叉间隙。","tier":"挑战"},{"id":185,"type":"single","stem":"某台平缝机在低速试缝时线迹正常，提速到高速后频繁断线，最可能的原因是","options":["梭皮压簧压力偏大","挑线杆过线部位有毛刺","针距调节盘锁紧不牢","压脚底面粗糙度超标"],"answer":[1],"explanation":"知识点是高速断线的常见成因。高速时线的运动速度加快，过线部位若有毛刺会因摩擦加剧而断线，所以正确项是挑线杆过线部位有毛刺；梭皮压簧压力偏大多造成底线紧、浮线而非高速断线；针距盘锁紧不牢影响针距稳定；压脚底面粗糙多造成缝料起皱或送布不畅。","tier":"进阶"},{"id":186,"type":"single","stem":"装配绷缝机时，若针杆高度调得过低，除了可能撞针外，还可能引起的现象是","options":["缝料反面出现跳针","装饰线覆盖宽度变窄","送布牙送布量增大","压脚提升高度减小"],"answer":[1],"explanation":"知识点是绷缝机针杆高度对线迹覆盖的影响。针杆过低会使装饰线覆盖宽度变窄，所以正确项是装饰线覆盖宽度变窄；反面跳针多由弯针勾线时机或线张力引起，不是针杆过低的主要表现；送布量由送布机构决定；压脚提升高度由提升机构决定，均与针杆高度无直接关系。","tier":"进阶"},{"id":187,"type":"single","stem":"某批平缝机在装配后试缝薄料时出现缝料被推挤起皱，而试缝厚料正常，最应先检查的是","options":["旋梭尖与机针的间隙","送布牙露出针板的高度","挑线杆的供线相位","梭芯绕线的整齐程度"],"answer":[1],"explanation":"知识点是送布牙高度与缝料厚薄的匹配。薄料起皱多因送布牙露出过高，所以正确项是送布牙露出针板的高度；旋梭间隙影响勾线而非起皱；挑线相位影响线迹松紧；梭芯绕线整齐度影响底线供给，不是薄料起皱的首查项。","tier":"进阶"},{"id":188,"type":"single","stem":"在调试平缝机的挑线杆供线量时，若挑线凸轮相位调得过早，最可能出现的现象是","options":["线迹正面浮线","线迹反面浮线","缝料被切断","机针弯曲"],"answer":[0],"explanation":"知识点是挑线凸轮相位与供线量的关系。相位过早会使收线不足，正面出现浮线，所以正确项是线迹正面浮线；反面浮线多由底线张力小引起；缝料切断与刀类机构有关；机针弯曲多由撞针或缝厚料引起。","tier":"基础"},{"id":189,"type":"single","stem":"某台包缝机在更换新弯针后出现频繁跳针，检查发现弯针尖有轻微毛刺，正确的处置是","options":["用细油石沿弯针尖原有角度轻轻修磨","用粗锉刀将弯针尖修短一截","把弯针尖向针板方向弯折少许","在弯针尖处涂抹少量润滑油"],"answer":[0],"explanation":"知识点是弯针尖毛刺的处理方法。应使用细油石按原有角度轻修，保持针尖形状，所以正确项是用细油石沿弯针尖原有角度轻轻修磨；粗锉修短会破坏勾线时机；弯折弯针会改变配合角度；涂油不能去除毛刺且可能沾污缝线。","tier":"挑战"},{"id":190,"type":"single","stem":"装配平缝机压脚机构时，若压脚提升后与针板平面仍保持接触，最可能的装配问题是","options":["压脚杆与压脚连接松动","压脚提升偏心轮位置装反","送布牙高度调得过低","针距调节盘未锁紧"],"answer":[1],"explanation":"知识点是压脚提升机构的装配关系。提升偏心轮装反会使提升量不足，压脚无法离开针板，所以正确项是压脚提升偏心轮位置装反；连接松动会造成压脚晃动而非不抬起；送布牙高度与压脚提升无关；针距盘锁紧影响针距而非压脚动作。","tier":"进阶"},{"id":191,"type":"single","stem":"工业平缝机装配时，针杆下端面到针板平面的距离调整不当，最先影响的是","options":["挑线杆收线时机","旋梭勾线时机","送布牙露出高度","压脚压力大小"],"answer":[2],"explanation":"针杆高度决定机针下降到最低点时与针板的相对位置，直接关联送布牙露出高度与勾线时机；挑线杆收线由凸轮相位决定，旋梭勾线由旋梭与机针的相对位置决定，压脚压力由调压螺钉控制，均不先受针杆高度影响。","tier":"基础"},{"id":192,"type":"single","stem":"绷缝机装配完成后试缝，发现线迹背面出现浮线，而正面线迹正常，首先应检查","options":["弯针与机针的配合间隙","压脚底面是否压住缝料","送布牙高度是否过高","上轮转动是否灵活"],"answer":[0],"explanation":"背面浮线多因弯针勾线后线环未能被正确拉住，弯针与机针的配合间隙及勾线时机是关键；压脚压料影响送布，送布牙高度影响送料量，上轮转动灵活度影响运转，均不直接造成背面浮线。","tier":"挑战"},{"id":193,"type":"single","stem":"包缝机装配时，下弯针与上弯针的交叉位置应保证两者在交叉时","options":["针尖相碰后错开","有0.5mm以上间隙","一针尖越过另一针背","两针尖同时到达同一平面"],"answer":[2],"explanation":"上下弯针交叉时必须一针尖越过另一针背，才能正确交换线环；针尖相碰会损伤针尖，0.5mm以上间隙会导致漏勾，两针尖同时到达同一平面则无法形成交叉勾线。","tier":"基础"},{"id":194,"type":"single","stem":"某厂装配一批高速平缝机，试缝时出现断针频繁，检查机针未弯曲、缝料厚度正常，下一步应重点检查","options":["旋梭梭尖是否磨损","针板孔是否与机针同心","挑线簧是否过紧","上轮皮带是否过松"],"answer":[1],"explanation":"断针频繁且机针与缝料正常时，多因机针下降时与针板孔不同心产生偏撞；梭尖磨损影响勾线，挑线簧过紧影响张力，皮带过松影响转速，均不直接造成断针。","tier":"进阶"},{"id":195,"type":"single","stem":"装配调试绷缝机时，需要同时满足的条件是","options":["弯针前后运动与机针上下运动同步","送布牙与压脚同时升降","挑线杆与上轮同向转动","旋梭与送布牙反向运动"],"answer":[0],"explanation":"绷缝机弯针做前后摆动，必须与机针上下运动保持严格同步才能勾线；送布牙与压脚并非同时升降，挑线杆与上轮转动方向无此要求，旋梭与送布牙反向运动也不是装配条件。","tier":"基础"},{"id":196,"type":"single","stem":"工业缝纫机装配后，用手转动上轮感觉某一位置明显发沉，最可能的原因是","options":["上轮轴承缺油","旋梭与机针相碰","挑线簧张力过大","压脚压力过大"],"answer":[1],"explanation":"转动到特定位置发沉说明该相位存在干涉，最常见是旋梭与机针相碰；轴承缺油会全程发沉，挑线簧张力与压脚压力不影响转动阻力。","tier":"基础"},{"id":197,"type":"single","stem":"包缝机试缝时出现跳针，检查发现弯针线环过大，正确的调整方法是","options":["增大弯针供线量","减小弯针供线量","提高压脚压力","降低送布牙高度"],"answer":[1],"explanation":"弯针线环过大导致线环不稳定而跳针，应减小弯针供线量使线环收紧；增大供线量会加剧线环过大，压脚压力和送布牙高度影响送料，与弯针线环大小无关。","tier":"挑战"},{"id":198,"type":"single","stem":"装配平缝机时，挑线杆的收线时机应与","options":["机针到达最低点同时","旋梭勾线完成同时","送布牙开始送料同时","压脚抬起同时"],"answer":[1],"explanation":"挑线杆应在旋梭勾线完成后及时收线，使线环从梭心套上脱出并形成线迹；与机针最低点、送布牙送料、压脚抬起均不是收线时机的对应关系。","tier":"基础"},{"id":199,"type":"single","stem":"某维修工装配完一台平缝机后，试缝发现线迹忽紧忽松，检查夹线器正常，最可能的原因是","options":["挑线簧变形或张力不稳","旋梭供油过多","机针型号偏大","上轮转速过高"],"answer":[0],"explanation":"线迹忽紧忽松而夹线器正常，多因挑线簧变形导致收线量波动；供油过多影响润滑，机针型号影响穿刺，上轮转速影响效率，均不造成张力周期性波动。","tier":"挑战"},{"id":200,"type":"single","stem":"某厂装配一台厚料平缝机，试缝时缝料背面出现线圈堆积，检查旋梭勾线正常，下一步应优先调整","options":["挑线簧张力","送布牙高度","压脚压力","旋梭供油量"],"answer":[0],"explanation":"背面线圈堆积说明收线不足，应优先调整挑线簧张力使收线充分；送布牙高度影响送料量，压脚压力影响压料，供油量影响润滑，均不直接解决收线不足。","tier":"基础"},{"id":201,"type":"single","stem":"工业平缝机装配后，用手转动上轮感觉整周阻力均匀但偏紧，最可能的原因是","options":["旋梭与梭壳间隙过小","送布牙高度超出针板平面","挑线杆行程调整过大","压脚压力调得过低"],"answer":[0],"explanation":"旋梭与梭壳间隙过小会使整周转动阻力均匀增大，是装配中常见的偏紧原因。送布牙过高主要影响送布与噪音，不造成整周均匀偏紧；挑线杆行程影响线迹松紧，不改变整周手感；压脚压力过低会使送布不稳，与转动阻力无关。","tier":"进阶"},{"id":202,"type":"single","stem":"调试锁缝机时发现线迹正面浮线、反面正常，应优先检查的部位是","options":["梭皮螺钉的夹线松紧","送布牙的齿尖磨损量","针杆高度的定位尺寸","压脚底面的平整程度"],"answer":[0],"explanation":"正面浮线说明底线张力偏小，应先检查梭皮螺钉夹线松紧。送布牙磨损影响送布不匀；针杆高度影响勾线时机；压脚底面影响压料，均不直接决定底面线张力平衡。","tier":"挑战"},{"id":203,"type":"single","stem":"装配包缝机时，压脚装好后踩下踏板压脚不落下，而手动扳压脚杆却能落下，首先应排查的环节是","options":["压脚杆与抬压脚连杆的连接销","针板与压脚的平行度","上弯针的摆动相位","差动牙的送布比例"],"answer":[0],"explanation":"手动能落而踏板不能落，说明抬压脚连杆与压脚杆的连接销位置或长度不对，属装配连接问题。针板平行度、弯针相位、差动比例均不影响压脚起落动作。","tier":"进阶"},{"id":204,"type":"single","stem":"工业缝纫机运转时出现规律性“咔哒”声，且每转一圈响一次，最可能的部位是","options":["旋梭与梭壳的配合面","机头罩壳的固定螺钉","电机皮带的松紧程度","油窗的密封垫圈"],"answer":[0],"explanation":"每转一圈响一次属与主轴同步的周期性异响，多来自旋梭与梭壳配合面碰擦。罩壳螺钉松、皮带松紧、油窗垫圈产生的响声不具每转一次的规律。","tier":"进阶"},{"id":205,"type":"single","stem":"调试高速平缝机时，发现缝料反面线环偏小且跳针，应首先调整的部位是","options":["旋梭勾线时机与针杆高度","挑线簧的弹力大小","送布牙的前后位置","压脚杆的高低位置"],"answer":[0],"explanation":"反面线环偏小伴跳针是勾线时机与针杆高度配合不当的典型表现，应先调旋梭勾线时机和针杆高度。挑线簧弹力、送布牙位置、压脚杆高低不直接决定线环大小。","tier":"挑战"},{"id":206,"type":"single","stem":"装配绷缝机时，弯针前后运动到位但左右摆幅偏小，应调整的部位是","options":["弯针摆动凸轮的偏心量","弯针前后凸轮的相位","针杆的上下定位","压脚的提升高度"],"answer":[0],"explanation":"左右摆幅由弯针摆动凸轮的偏心量决定，偏小应调偏心量。前后凸轮相位管前后运动；针杆定位管勾线；压脚提升高度与弯针摆幅无关。","tier":"进阶"},{"id":207,"type":"single","stem":"工业缝纫机装配完成后试机，发现机头油窗不上油，最先应检查的是","options":["油泵转子与油泵轴的装配方向","油窗玻璃的透光程度","油盘内油量的多少","回油管的固定卡子"],"answer":[0],"explanation":"油泵转子装反或与油泵轴配合方向错会导致不上油，是装配环节首要排查点。油窗透光、油量多少、回油管卡子属使用或辅助因素，不是装配后不上油的首查项。","tier":"挑战"},{"id":208,"type":"single","stem":"调试平头锁眼机时，切刀切出的扣眼两端长度不一致，最应检查的部位是","options":["切刀与针板的相对位置","切刀压力弹簧的弹力","切刀驱动凸轮的转速","切刀刀的锋利程度"],"answer":[0],"explanation":"扣眼两端长度不一致说明切刀与针板相对位置有偏差，导致两端切距不等。弹簧弹力、凸轮转速、刀刃锋利度影响切口质量，不造成两端长度差。","tier":"进阶"},{"id":209,"type":"single","stem":"装配双针平缝机后试缝，发现两行线迹间距忽大忽小，最可能的原因是","options":["两针杆的间距定位松动","两梭壳的夹线力不同","两针的粗细不一致","两压脚的底面不平"],"answer":[0],"explanation":"两行线迹间距忽大忽小是针杆间距定位松动导致针距变化。梭壳夹线力不同会造成两行张力差；针粗细、压脚底面影响线迹质量，不改变行距。","tier":"挑战"},{"id":210,"type":"single","stem":"某厂装配的工业平缝机在连续运转两小时后出现旋梭部位温升明显偏高，下列处置中最合理的是","options":["检查旋梭供油量并复核旋梭与梭壳间隙","停机冷却后继续使用观察","更换黏度更高的润滑油","降低电机转速继续生产"],"answer":[0],"explanation":"旋梭温升偏高多因供油不足或间隙过小，应先检查供油并复核间隙。停机冷却、换高黏度油、降速生产均属掩盖问题，不解决根本原因。","tier":"挑战"},{"id":211,"type":"multi","stem":"工业缝纫机装配调试中，下列哪些做法有助于保证针杆与旋梭的配合精度","options":["用百分表复核针杆下死点位置","按机型规定值调整旋梭勾线时机","装配前清洁旋梭与梭壳配合面","用手感判断针杆与旋梭间隙后直接锁紧","以电机空转声音判断勾线时机"],"answer":[0,1,2],"explanation":"百分表复核针杆下死点、按规定值调勾线时机、装配前清洁配合面均能保证配合精度。手感判断后直接锁紧缺乏量化依据；凭电机空转声音判断勾线时机不准确，均不可取。","tier":"挑战"},{"id":212,"type":"single","stem":"工业平缝机装配时，针杆下端面到针板平面的距离若小于标准值，最可能直接引起哪种现象？","options":["缝料起皱且线迹浮松","机针与旋梭尖相撞","挑线杆供线量不足","压脚压力明显偏小"],"answer":[1],"explanation":"知识点：针杆高度决定机针与旋梭的配合间隙。针杆过低使机针下行过深，旋梭尖会撞到机针，正确项为机针与旋梭尖相撞。缝料起皱多与送布牙高度或压脚压力有关；挑线杆供线量由挑线凸轮相位决定；压脚压力由调压螺钉控制，均与针杆下端面距离无直接因果。","tier":"进阶"},{"id":213,"type":"single","stem":"装配旋梭时，梭尖与机针中心线的相对位置应满足的要求是？","options":["梭尖略高于针孔上缘","梭尖对准针孔上缘略下方","梭尖低于针孔下缘两毫米","梭尖与针孔中心完全等高"],"answer":[1],"explanation":"知识点：旋梭勾线时机由梭尖与针孔的位置关系决定。梭尖应对准针孔上缘略下方，才能可靠勾住线环，正确项为对准针孔上缘略下方。梭尖过高会勾不到线环或勾在针杆上；梭尖低于针孔下缘会漏勾；与针孔中心完全等高时线环尚未充分形成，勾线不稳定。","tier":"基础"},{"id":214,"type":"single","stem":"缝纫机送布牙装配后，牙尖露出针板平面的高度通常应控制在什么范围？","options":["0.3至0.5毫米","0.8至1.0毫米","1.5至2.0毫米","2.5至3.0毫米"],"answer":[1],"explanation":"知识点：送布牙高度影响送布力和缝料损伤。常规工业平缝机牙尖露出针板约0.8至1.0毫米，正确项为该范围。0.3至0.5毫米露出过少，送布无力易滞料；1.5毫米以上露出过多，会刮伤缝料并造成送布不均；2.5至3.0毫米明显过高。","tier":"基础"},{"id":215,"type":"single","stem":"平缝机调试时发现线迹底面浮线、面线张力偏小，优先应调节的部件是？","options":["旋梭定位钩位置","夹线器调节螺母","送布牙偏心轮","挑线杆曲柄角度"],"answer":[1],"explanation":"知识点：面线张力由夹线器控制，底面浮线说明面线张力不足。夹线器调节螺母可增大面线张力，正确项为该部件。旋梭定位钩影响脱线顺畅而非张力大小；送布牙偏心轮决定送布轨迹；挑线杆曲柄角度影响供线与收线时机，均不直接解决张力偏小问题。","tier":"挑战"},{"id":216,"type":"single","stem":"装配挑线杆机构时，若挑线杆供线时间过早，最可能出现的线迹缺陷是？","options":["线迹收线过紧断线","线环形成不稳定跳针","缝料背面出现毛巾状浮线","针距忽大忽小不匀"],"answer":[2],"explanation":"知识点：挑线杆供线相位决定线环形成与收线的配合。供线过早会使面线在收线前被过多放出，背面出现浮线，正确项为背面毛巾状浮线。收线过紧断线多因供线过晚；线环不稳跳针与旋梭勾线时机有关；针距不匀由送布机构引起。","tier":"进阶"},{"id":217,"type":"single","stem":"某操作工装配平缝机后试车，发现机器运转时声音沉闷且机头温度偏高，下列排查顺序中最合理的是？","options":["先查旋梭间隙再查油路供油","先查油路供油再查各轴配合间隙","先拆挑线杆再查夹线器张力","先调送布牙高度再查压脚压力"],"answer":[1],"explanation":"知识点：运转沉闷伴温升多为润滑不足或运动件配合过紧。应先确认油路供油是否正常，再检查各轴配合间隙，正确项为该顺序。先查旋梭间隙无法解释整机温升；拆挑线杆与张力调节和温升无关；送布牙高度与压脚压力不引起机头闷响发热。","tier":"挑战"},{"id":218,"type":"single","stem":"装配平缝机下轴时，下轴轴向窜动量过大会直接导致哪种故障？","options":["旋梭勾线时机不稳定","面线夹线器打滑","压脚抬升高度不足","绕线器计数不准"],"answer":[0],"explanation":"知识点：下轴轴向定位影响旋梭相位。窜动过大会使旋梭与机针的配合时机漂移，正确项为勾线时机不稳定。夹线器打滑属张力机构问题；压脚抬升高度由抬压脚机构决定；绕线器计数由绕线机构控制，均与下轴窜动无关。","tier":"基础"},{"id":219,"type":"single","stem":"装配绷缝机时，若针杆高度调得过低，除易撞弯针外还可能引起哪种后果？","options":["线迹密度变大","勾线时线环过小","送布牙露出过高","压脚压力自动增大"],"answer":[1],"explanation":"知识点：针杆过低使机针上升行程缩短，线环来不及充分形成。后果之一是勾线时线环过小，正确项为该现象。线迹密度由送布机构决定；送布牙高度由牙架调整；压脚压力由调压螺钉设定，均不因针杆高度变化而改变。","tier":"基础"},{"id":220,"type":"single","stem":"某维修工装配平缝机后，用手转动飞轮感觉时紧时松，下列处置中最恰当的是？","options":["直接通电试车观察是否自愈","检查各轴同轴度及齿轮啮合情况","仅向油孔加注润滑油后交付","调大皮带张力后继续装配"],"answer":[1],"explanation":"知识点：手转时紧时松说明存在同轴度偏差或齿轮啮合不良。应检查各轴同轴度及齿轮啮合，正确项为该做法。直接通电试车可能扩大损伤；只加油不解决机械偏差；调大皮带张力与内部时紧时松无关且会加剧轴承负荷。","tier":"挑战"},{"id":221,"type":"single","stem":"平缝机装配完成后进行缝纫试验，发现针距调节盘指示值与实际针距偏差较大，应重点检查？","options":["送布凸轮与送布牙的传动比","旋梭与机针的配合间隙","挑线杆的供线相位","夹线器的张力大小"],"answer":[0],"explanation":"知识点：针距由送布机构传动比决定。指示值与实际偏差大，应检查送布凸轮与送布牙的传动比，正确项为该部件。旋梭间隙影响勾线；挑线相位影响线迹松紧；夹线器张力影响浮线，均不改变针距大小。","tier":"挑战"},{"id":222,"type":"multi","stem":"装配工业平缝机时，下列哪些做法有助于保证旋梭勾线可靠？","options":["校正针杆高度使梭尖对准针孔上缘略下方","调整旋梭与机针间隙至微小配合","保证旋梭定位钩与梭架缺口间隙适当","将旋梭油量调至最大以降低磨损","把机针换成粗一号以增大线环"],"answer":[0,1,2],"explanation":"知识点：旋梭勾线可靠性取决于针杆高度、梭尖与机针间隙及定位钩间隙。前三项分别保证勾线位置、配合间隙和脱线顺畅，均正确。油量过大会污染缝料且不改善勾线；换粗机针改变针孔位置，反而可能破坏原有配合。","tier":"进阶"},{"id":223,"type":"single","stem":"工业平缝机装配时，针杆下端面到针板平面的距离应通过哪个零件的调整来保证","options":["针杆连接柱的夹紧螺钉","针杆曲柄上的针杆夹紧螺钉","送布牙架的偏心轴","压脚杆的调节螺钉"],"answer":[1],"explanation":"知识点是针杆高度的调整部位。针杆高度由针杆曲柄处的夹紧螺钉松开后上下移动针杆来确定，故B正确；A是固定针杆连接柱的，松开后不能改变针杆高低；C调节送布牙高低与针杆高度无关；D调节压脚压力，不改变针杆位置。","tier":"进阶"},{"id":224,"type":"single","stem":"工业平缝机旋梭与机针的配合中，机针从下死点回升时形成线环，旋梭梭尖应在此刻勾住线环，梭尖与机针中心线的正确位置关系是","options":["梭尖对准机针中心线并略有间隙","梭尖超过机针中心线约2mm","梭尖低于针孔上缘约1mm","梭尖贴紧机针侧面不留间隙"],"answer":[0],"explanation":"知识点是旋梭勾线时机与位置。梭尖应在机针回升形成线环时对准针中心线且留微小间隙，故A正确；B梭尖超过中心线过多会勾不住线环或断针；C梭尖位置过低会错过线环；D贴紧无间隙会磨损机针并断线。","tier":"进阶"},{"id":225,"type":"single","stem":"装配工业缝纫机送布机构后试车发现缝料出现规律性横向针距不匀，首先应检查的部位是","options":["送布牙牙齿的磨损程度","送布凸轮与抬牙凸轮的相位","挑线簧的张力大小","旋梭供油量的大小"],"answer":[1],"explanation":"知识点是送布机构相位对针距的影响。针距不匀多因送布凸轮与抬牙凸轮相位配合不当，故B正确；A牙齿磨损影响送布力大小而非规律性横距；C挑线簧张力影响线迹松紧；D供油量影响润滑，与针距无关。","tier":"挑战"},{"id":226,"type":"single","stem":"某操作工装配完一台高速包缝机后，用手转动皮带轮感觉全程阻力均匀但偏大，最可能的原因是","options":["主轴轴承预紧过度","下弯针位置装反","压脚压力调得过小","针距调节盘未锁紧"],"answer":[0],"explanation":"知识点是装配后转动阻力的判断。全程均匀偏大通常是轴承预紧过度或配合过紧，故A正确；B下弯针装反会造成局部卡阻或碰撞；C压脚压力小不会造成转动力矩增大；D针距盘未锁紧不影响转动阻力。","tier":"进阶"},{"id":227,"type":"single","stem":"工业平缝机挑线杆的运动与机针运动的关系，下列叙述正确的是","options":["挑线杆与机针同步上下运动","挑线杆在机针上升时收线、下降时放线","挑线杆仅在机针停顿时动作","挑线杆由送布轴直接驱动"],"answer":[1],"explanation":"知识点是挑线机构的作用时机。挑线杆在机针上升阶段收回多余线量、下降阶段放出线量，故B正确；A两者并非同步同向；C挑线杆是连续运动的；D挑线杆一般由主轴上的挑线凸轮驱动，不是送布轴。","tier":"基础"},{"id":228,"type":"single","stem":"装配工业缝纫机压脚机构时，压脚杆下端面与针板平面的配合要求是","options":["压脚抬起时与针板保持约5mm间隙","压脚落下时与针板平面贴合","压脚落下时与针板保持0.5mm间隙","压脚落下时低于针板平面"],"answer":[1],"explanation":"知识点是压脚装配的基本要求。压脚落下时应与针板平面贴合以压住缝料，故B正确；A抬起间隙过大不影响缝纫但非落下要求；C留0.5mm会使缝料压不实；D低于针板会碰针板并损伤缝料。","tier":"进阶"},{"id":229,"type":"single","stem":"工业缝纫机试缝时出现断续跳针，检查发现机针装反、针尖有毛刺且针杆偏高，正确的处置顺序是","options":["先换针再调针杆高度然后试缝","先调针杆高度再换针然后试缝","先修磨针尖再调针杆高度然后试缝","先调旋梭位置再换针然后试缝"],"answer":[0],"explanation":"知识点是跳针故障的排除顺序。应先排除机针本身问题（装反、毛刺），再调整针杆高度，最后试缝验证，故A正确；B调针杆前未换针会重复出错；C针尖有毛刺应换针而非修磨；D未换针先调旋梭会掩盖真因。","tier":"挑战"},{"id":230,"type":"single","stem":"某维修工装配工业平缝机后试车，发现缝料下面线迹浮线、上面线紧，正确的调整方向是","options":["增大挑线簧张力","增大梭皮螺钉压力","减小梭皮螺钉压力","增大压脚压力"],"answer":[2],"explanation":"知识点是线迹浮线的调整。下面浮线说明底线太松，应减小梭皮螺钉压力使底线张力减小，故C正确；A挑线簧张力增大使面线更紧；B增大梭皮压力使底线更紧；D压脚压力影响送布，不改变线迹松紧。","tier":"挑战"},{"id":231,"type":"single","stem":"工业缝纫机针杆与旋梭的装配中，机针下降到下死点时梭尖应位于机针缺口的位置是","options":["梭尖对准机针缺口上缘","梭尖对准机针缺口下缘","梭尖位于缺口中部","梭尖高于缺口上缘2mm"],"answer":[2],"explanation":"知识点是机针缺口与梭尖的配合位置。机针下死点时梭尖应位于机针缺口中部附近，故C正确；A上缘偏高会勾线过早；B下缘偏低会勾线过晚；D高于缺口过多会碰针或勾不住线。","tier":"进阶"},{"id":232,"type":"single","stem":"工业平缝机装配后试缝时出现规律性针距忽长忽短，送布牙高度和压脚压力均已确认正常，下一步应优先检查的是","options":["送布凸轮与主轴的相对相位是否松动偏移","针杆高度是否比标准值低了半毫米","旋梭供油量是否调得偏大","挑线簧弹力是否调得过紧"],"answer":[0],"explanation":"知识点为送布机构相位与针距稳定性。送布凸轮相位松动偏移会使送布量与针杆运动不匹配，导致规律性针距波动，故正确。针杆高度偏低主要引起跳针断线，不直接造成针距忽长忽短；旋梭供油量偏大影响润滑与油污，不改变针距；挑线簧过紧影响线迹张力与收线，不改变送布量。","tier":"进阶"},{"id":233,"type":"single","stem":"装配高速包缝机时，按工艺要求调整上弯针与下弯针的交叉间隙，正确的操作顺序是","options":["先固定下弯针位置，再调上弯针与下弯针交叉留隙，最后复查前后间隙","先调上弯针前后间隙，再固定下弯针，最后调交叉留隙","上下弯针同时松开，边转手轮边同时锁紧两针","先调弯针摆轴轴向窜动，再调交叉留隙，最后固定下弯针"],"answer":[0],"explanation":"知识点为包缝机弯针配合的调整顺序。先固定下弯针作为基准，再调上弯针交叉留隙，最后复查前后间隙，可避免反复松动基准，故正确。先调上弯针再固定下弯针会失去基准；两针同时松开锁紧无法保证交叉量；先调摆轴窜动再调交叉留隙顺序颠倒，窜动应在配合调整前处理但不作为此步首项。","tier":"进阶"},{"id":234,"type":"single","stem":"某厂装配的电脑平缝机在缝制薄料时线迹背面出现浮线，操作工已把夹线器张力调大仍无改善，正确的下一步处置是","options":["检查挑线杆供线量与挑线簧行程是否匹配薄料需求","继续加大夹线器压力直到浮线消失","更换更大号的机针以增加线环","把压脚压力调低使面料更容易移动"],"answer":[0],"explanation":"知识点为薄料浮线的成因与调节。薄料浮线常因挑线杆供线与挑线簧行程不匹配，收线不足，故应检查挑线机构，正确。继续加大夹线力会断线或起皱；换大号机针会扩大针孔、加剧浮线；降低压脚压力会使送布不稳，不解决收线问题。","tier":"挑战"},{"id":235,"type":"single","stem":"装配工业平缝机时，旋梭与机针的配合间隙通常要求机针回升时梭尖正好进入针线环，若梭尖过早接触针线环，最可能造成的后果是","options":["线环被过早勾住导致跳针或断线","针距变大且线迹变稀","送布牙刮伤面料表面","梭壳发热使润滑油变稀"],"answer":[0],"explanation":"知识点为旋梭勾线时机。梭尖过早进入线环会勾住未充分形成的线环，造成跳针或断线，故正确。针距由送布机构决定，与勾线时机无关；送布牙刮料属压脚与牙高问题；梭壳发热与供油和转速相关，非勾线时机直接后果。","tier":"进阶"},{"id":236,"type":"single","stem":"装配某型工业缝纫机时，需要保证针杆下死点时针尖与针板平面的距离符合工艺，若该机型要求针尖略低于针板平面，正确的测量基准是","options":["以针板平面为基准测量针尖露出或低于的量","以送布牙最高点为基准测量针尖高度","以压脚底面为基准测量针尖高度","以旋梭梭尖为基准测量针尖高度"],"answer":[0],"explanation":"知识点为针杆高度的测量基准。针杆高度以针板平面为基准测量针尖相对位置，故正确。送布牙最高点、压脚底面、旋梭梭尖均非针杆高度的规定基准，用它们测量会得出错误结论。","tier":"进阶"},{"id":237,"type":"single","stem":"装配工业缝纫机时，为减少高速运转下机头噪声，对针杆与上下衬套的配合通常采取的措施是","options":["选配间隙合适的衬套并保证润滑通道畅通","把衬套压得越紧越好以消除一切间隙","在衬套外圆缠绕生料带填补间隙","把针杆直径车小再装入衬套"],"answer":[0],"explanation":"知识点为针杆衬套配合与润滑。选配合适间隙并保证润滑可降低噪声与磨损，故正确。压得过紧会发热卡死；缠生料带会改变配合且不耐油；车小针杆会破坏配合精度与强度。","tier":"进阶"},{"id":238,"type":"multi","stem":"在装配调试工业缝纫机时，以下关于机针与旋梭配合的操作要求，正确的有","options":["机针下死点时旋梭梭尖应位于针孔上方约1至1.5毫米","梭尖与机针的侧向间隙应尽量小但不接触","机针回升2至3毫米时梭尖应正好勾住线环","旋梭供油量越大越能保证高速运转不发热","机针装反后只要旋梭位置对仍可正常勾线"],"answer":[0,1,2],"explanation":"知识点为机针与旋梭配合要求。梭尖位于针孔上方约1至1.5毫米、侧向间隙小但不接触、机针回升2至3毫米时勾住线环，均为正确要求。供油量过大会造成油污与浪费，并非越大越好；机针装反会改变线环方向与勾线位置，不能正常勾线。","tier":"挑战"},{"id":239,"type":"single","stem":"工业平缝机装配时，针杆下端面到针板上平面的距离若小于标准值，最可能引起下列哪种现象","options":["缝料反面出现浮线","机针与旋梭尖相撞","挑线杆供线量不足","压脚压力明显下降"],"answer":[1],"explanation":"知识点是针杆高度与旋梭的配合关系。针杆过低时，机针下行深度增大，针尖会与旋梭尖发生干涉甚至相撞，故正确项为机针与旋梭尖相撞。缝料反面浮线主要与底线张力或旋梭定位钩间隙有关；挑线杆供线量由挑线凸轮相位决定，与针杆高度无直接关系；压脚压力由压脚调节螺钉控制，与针杆高度无关。","tier":"进阶"},{"id":240,"type":"single","stem":"装配工业缝纫机旋梭时，旋梭定位钩与旋梭之间的间隙通常应调整到机针能顺利通过又不使旋梭窜动，若该间隙调得过小，最直接的后果是","options":["旋梭转动阻力增大并发热","梭尖勾线时间提前","底线张力自动变小","送布牙高度降低"],"answer":[0],"explanation":"知识点是旋梭定位钩间隙的作用。定位钩间隙过小会夹住旋梭外圆，使旋梭转动阻力增大、运转发热，故正确项为旋梭转动阻力增大并发热。梭尖勾线时间由旋梭与机针的相对相位决定，不由定位钩间隙决定；底线张力由梭皮螺钉调节；送布牙高度由送布牙升降偏心或牙架高度决定，与定位钩无关。","tier":"进阶"},{"id":241,"type":"single","stem":"平缝机在缝制薄料时出现针迹忽长忽短，检查发现压脚压力偏大且送布牙露出针板过高，下一步应优先","options":["调小压脚压力并降低送布牙高度","调大压脚压力并升高送布牙高度","更换更细的机针并调紧底线","调松挑线簧并减小挑线量"],"answer":[0],"explanation":"知识点是薄料缝纫时压脚压力与送布牙高度的匹配。压力过大和送布牙过高会使薄料被压住或顶起，造成送布不匀，故应调小压力并降低送布牙高度，正确项为调小压脚压力并降低送布牙高度。调大压力、升高送布牙会加重症状；换细针和调底线不解决送布不匀；调挑线簧影响线迹张力而非针距。","tier":"挑战"},{"id":242,"type":"single","stem":"工业缝纫机装配后试车，发现机器在高速运转时振动明显并伴有周期性噪声，而低速时正常，最可能的原因是","options":["上轴与下轴联轴节相位装错","手轮紧固螺钉未拧紧","挑线杆过线孔有毛刺","梭心套弹簧片弹力过小"],"answer":[1],"explanation":"知识点是高速振动与旋转件平衡。手轮紧固螺钉未拧紧会使手轮在高速时产生松动和偏心，引起振动和周期性噪声，故正确项为手轮紧固螺钉未拧紧。联轴节相位装错会引起勾线时间错误而非单纯振动；过线孔毛刺影响断线；梭心套弹簧片影响底线张力，均与高速振动无直接关系。","tier":"挑战"},{"id":243,"type":"single","stem":"装配平缝机送布机构时，送布牙在针板槽中的前后运动应使送布牙前端在针板槽前边缘露出约一个牙距，若调整后送布牙露出过多，会直接导致","options":["缝料被咬破或起皱","机针频繁断针","旋梭尖磨损加快","挑线杆行程减小"],"answer":[0],"explanation":"知识点是送布牙露出高度的作用。送布牙露出过多会过度抓持缝料，造成薄料咬破或起皱，故正确项为缝料被咬破或起皱。断针多与针杆高度、旋梭相位有关；旋梭磨损与勾线配合有关；挑线杆行程由挑线凸轮决定，与送布牙露出高度无关。","tier":"基础"},{"id":244,"type":"single","stem":"调试平缝机时，机针从最低点上升约2毫米时旋梭尖应到达机针中心线，这一参数主要影响","options":["勾线时机与跳针","底线张力大小","压脚提升高度","绕线器绕线量"],"answer":[0],"explanation":"知识点是旋梭勾线时机的标准。机针上升约2毫米时梭尖应到达针中心线，这个时机决定勾线是否可靠，故正确项为勾线时机与跳针。底线张力由梭皮螺钉调节；压脚提升高度由压脚杆和膝控机构决定；绕线器绕线量由绕线轮调节，均与该参数无关。","tier":"基础"},{"id":245,"type":"single","stem":"某台工业平缝机在缝制厚料时出现断针，检查发现机针装反且针杆高度偏高，正确的处理顺序是","options":["先换针并调低针杆，再试缝检查勾线","先调大压脚压力，再更换粗号机针","先调松底线张力，再调整旋梭位置","先降低送布牙高度，再调挑线簧张力"],"answer":[0],"explanation":"知识点是断针故障的排查顺序。机针装反和针杆偏高是断针的直接原因，应先纠正装针方向并调低针杆，再试缝验证勾线，故正确项为先换针并调低针杆，再试缝检查勾线。调大压力或换粗针不解决装反问题；调底线和旋梭位置不针对装反；降低送布牙和调挑线簧与断针主因无关。","tier":"挑战"},{"id":246,"type":"single","stem":"装配包缝机时，下弯针与上弯针的交叉量过小，缝制时最可能出现的缺陷是","options":["链线跳针","线迹过紧","缝料起皱","针迹密度变大"],"answer":[0],"explanation":"知识点是包缝机上下弯针交叉量与链线形成。交叉量过小会使弯针之间不能可靠交接缝线，造成链线跳针，故正确项为链线跳针。线迹过紧由张力调节决定；缝料起皱与压脚压力和送布有关；针迹密度由送布牙与差动调节决定，与弯针交叉量无关。","tier":"进阶"},{"id":247,"type":"single","stem":"工业缝纫机装配完成后进行空车运转试验，下列做法符合调试程序的是","options":["先低速运转听声，再逐步升速并检查各机构","直接高速运转以快速检验机器性能","先调好线迹张力再空车运转","先装上缝料试缝再空车运转"],"answer":[0],"explanation":"知识点是装配后的试车程序。应先低速运转检查有无异常声响和卡阻，再逐步升速检查各机构，故正确项为先低速运转听声，再逐步升速并检查各机构。直接高速运转容易掩盖或扩大故障；张力和试缝应在空车运转正常后进行，程序颠倒。","tier":"进阶"},{"id":248,"type":"single","stem":"某维修人员调试平缝机时，发现旋梭尖磨损严重，他直接更换了新旋梭但未重新调整勾线时机，试缝后出现跳针，错误的环节是","options":["更换旋梭后未重新校正勾线时机","更换旋梭前未清洗梭床","更换旋梭时未更换梭心套","更换旋梭后未调整压脚压力"],"answer":[0],"explanation":"知识点是更换旋梭后必须重新校正勾线时机。新旋梭与旧旋梭的梭尖位置可能存在差异，不重新调整会导致勾线不良而跳针，故错误环节是更换旋梭后未重新校正勾线时机。清洗梭床、更换梭心套、调整压脚压力都不是本次跳针的直接原因。","tier":"挑战"},{"id":249,"type":"single","stem":"工业平缝机装配时，针杆下端面到针板平面的距离应通过调整哪个零件来保证","options":["针杆连接柱的紧固螺钉位置","压脚杆调节螺钉的旋入深度","送布牙架的前后偏心销","挑线杆过线孔的开口方向"],"answer":[0],"explanation":"知识点是针杆高度的装配基准。针杆连接柱连同针杆一起被紧固螺钉锁定，松开后上下移动即可改变针杆下端面与针板平面的间距；压脚杆调节螺钉只改变压脚压力与抬升量，不改变针杆高度；送布牙架偏心销调整的是送布牙的行程与前后位置；挑线杆过线孔方向影响挑线量而非针杆高度。","tier":"进阶"},{"id":250,"type":"single","stem":"工业平缝机旋梭与机针的配合时间，通常应调到机针从下死点回升多少时旋梭尖到达机针中心线","options":["约1毫米","约2毫米","约4毫米","约6毫米"],"answer":[1],"explanation":"知识点是勾线时机。标准配合是机针由下死点回升约2毫米时旋梭尖抵达机针中心线，此时针孔上方留有足够容线空间且线圈稳定。1毫米时机针回升不足、线环尚未充分形成，容易跳针；4毫米与6毫米时机针回升过多，线环已扭曲或收小，旋梭尖易勾空或勾断线。","tier":"进阶"},{"id":251,"type":"single","stem":"装配工业平缝机时，送布牙上升到最高位置时，其齿顶应高出针板平面一定量，正确范围是","options":["0.2至0.4毫米","0.8至1.0毫米","1.5至2.0毫米","2.5至3.0毫米"],"answer":[1],"explanation":"知识点是送布牙高度。齿顶高出针板平面0.8至1.0毫米时既能有效抓布又不会顶起压脚或刮伤面料。0.2至0.4毫米抓布力不足，薄料易打滑；1.5毫米以上会明显顶起压脚、造成送布不畅和面料起皱；2.5毫米以上属严重超高，还会撞击压脚底板。","tier":"基础"},{"id":252,"type":"single","stem":"平缝机挑线杆供线量不足，缝纫时线迹呈现的典型现象是","options":["底面线迹浮在面料正面形成浮线","面线在缝料中收紧、线迹下凹","针距忽大忽小且送布打滑","旋梭发出有节奏的撞击声"],"answer":[0],"explanation":"知识点是挑线杆供线与收线的关系。供线不足时面线在收线阶段被拉紧而把底线从面料正面拉起，形成正面浮线。面线收紧、线迹下凹通常是面线张力过大；针距忽大忽小属送布机构问题；旋梭撞击声属旋梭与机针配合或旋梭轴间隙问题，与挑线量无直接关系。","tier":"基础"},{"id":253,"type":"single","stem":"某台平缝机空转正常，但一踩踏板缝纫就出现连续断针，检查机针未弯曲、针板孔无毛刺，下一步应重点检查","options":["压脚压力是否偏大","旋梭尖是否勾到机针","挑线簧的弹力是否过强","过线孔是否被线屑堵塞"],"answer":[1],"explanation":"知识点是断针的常见机械原因。空转正常说明传动无碍，一旦缝纫才断针，多因旋梭与机针的间隙或配合时机不对，旋梭尖在勾线时撞到机针。压脚压力偏大只会造成送布不畅与压痕；挑线簧弹力过强影响线迹张力而非断针；过线孔堵塞会造成断线，不会造成断针。","tier":"进阶"},{"id":254,"type":"single","stem":"包缝机装配后试缝，发现缝料边缘出现稀疏的跳针，而机针与弯针的配合时间已按标准调好，应优先检查","options":["弯针的勾线距是否合适","上下刀的咬合量是否过大","送布牙的齿顶高度是否过高","压脚底面的粗糙度是否过大"],"answer":[0],"explanation":"知识点是包缝机弯针勾线距对跳针的影响。配合时间正确但仍有跳针，常因弯针勾线距偏大，弯针尖未能稳定进入机针线环。上下刀咬合量过大会造成切边不齐或崩刀；送布牙过高影响送布平稳；压脚粗糙度影响压痕，三者均不直接造成跳针。","tier":"挑战"},{"id":255,"type":"single","stem":"绷缝机在装配调试时，若出现缝料正面有规律地每隔几针出现一个线圈凸起，通常与哪个机构的调整有关","options":["弯针前后运动偏心轮的定位","上刀与下刀的咬合深度","压脚杆的高低位置","过线板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anation":"知识点：浮线故障排查顺序。面线调紧无效时应查底线张力是否过小；一味加大面线张力会断线或起皱；换粗针会扩大针孔反而不利薄料；调高送布牙与浮线成因无关。","tier":"挑战"},{"id":273,"type":"single","stem":"装配工业缝纫机时，压脚杆与压脚杆套筒之间正确的配合状态是","options":["压脚杆能在套筒内自由上下滑动且无明显径向旷动","压脚杆与套筒过盈配合以保证压脚不晃动","压脚杆与套筒留出较大间隙以便快速装拆","压脚杆装入后需用铜锤敲紧使其固定"],"answer":[0],"explanation":"知识点：压脚杆配合。正确是自由滑动且无径向旷动，保证压脚压力稳定；过盈配合会使压脚无法正常升降；间隙过大会导致压脚歪斜；敲紧会损伤配合面并失去滑动功能。","tier":"进阶"},{"id":274,"type":"single","stem":"装配平缝机针杆时，机针装好后针尖与针板容针孔的中心偏差应控制在","options":["针尖能自由落入容针孔中心且不碰孔壁","针尖偏离中心约针孔半径的一半","针尖紧靠容针孔一侧孔壁","针尖超出容针孔前边缘约1mm"],"answer":[0],"explanation":"知识点：机针与针板对中。正确是针尖自由落入孔中心不碰壁；偏半个半径易碰针板断针；紧靠孔壁会磨针断线；超出前边缘根本无法正常缝纫。","tier":"进阶"},{"id":275,"type":"single","stem":"工业平缝机装配时，针杆下端面到针板平面的距离调整通常依据什么来确定","options":["机头壳体上刻印的针距标线位置","旋梭梭尖与机针中心的配合时机","送布牙露出针板的高度尺寸","压脚底面与针板的贴合程度"],"answer":[1],"explanation":"针杆高度本质决定机针与旋梭的勾线时机，因此依据旋梭梭尖与机针中心的配合时机确定。机头刻线是参考基准但非最终依据；送布牙高度属送布机构调整；压脚贴合属压脚压力调整，均不决定针杆高度。","tier":"进阶"},{"id":276,"type":"single","stem":"调试平缝机旋梭时，梭尖到达机针中心线时，机针针孔上沿应处于什么位置","options":["梭尖正好对准针孔上沿略下方","梭尖高于针孔上沿约两毫米","梭尖低于针孔上沿约两毫米","梭尖与针孔下沿保持齐平"],"answer":[0],"explanation":"正确时机是梭尖到达机针中心时略高于针孔上沿，使梭尖能稳定进入针线环。高于上沿两毫米会错过线环；低于上沿两毫米或齐平下沿则勾不住线环，造成跳针。","tier":"进阶"},{"id":277,"type":"single","stem":"装配工业缝纫机送布机构后，送布牙在最高位置露出针板平面的高度通常应控制为多少","options":["约零点三毫米","约零点九毫米","约一点五毫米","约二点五毫米"],"answer":[1],"explanation":"送布牙最高位置露出针板约零点九毫米是常规范围，能保证送布力又不刮伤面料。零点三毫米送布无力易打滑；一点五毫米和两点五毫米过高会顶起面料、造成送料不均和断针。","tier":"进阶"},{"id":278,"type":"single","stem":"平缝机运转时出现规律性跳针，且只在缝厚料时发生，最可能的原因是","options":["旋梭供油量偏大导致线环散乱","机针与旋梭勾线时机偏晚","挑线簧张力偏小使线环过大","压脚压力偏小使面料浮起"],"answer":[1],"explanation":"厚料时针线环形成晚，若勾线时机偏晚则梭尖错过线环，产生规律跳针。供油量偏大影响润滑不直接影响勾线；挑线簧张力偏小主要影响线迹松紧；压脚压力偏小影响送料，均非厚料跳针主因。","tier":"挑战"},{"id":279,"type":"single","stem":"装配缝纫机时发现机针在针板孔内偏向一侧，可能刮擦针板，正确的调整顺序是","options":["先调针杆高低再调针板左右位置","先调针板孔中心再复查针杆垂直度","先调机针与旋梭间隙再调针板","先调送布牙高度再调机针位置"],"answer":[1],"explanation":"机针偏心刮针板应先确认针板孔中心与针杆轴线对中，再复查针杆垂直度，避免误调其他机构。先调针杆高低、旋梭间隙或送布牙高度均未解决对中问题，属顺序错误。","tier":"挑战"},{"id":280,"type":"single","stem":"工业包缝机上弯针与机针的配合，正确的关系是","options":["机针下降到最低点时弯针应到达最左位置","机针上升时弯针从机针后方穿过针线环","弯针在最右位置时与机针保持两毫米间隙","机针下降时弯针应同步向右侧退回"],"answer":[1],"explanation":"包缝机勾线靠弯针在机针上升形成线环时从后方穿过。机针最低点弯针应在行程中段；弯针最右位置间隙应更小；机针下降时弯针应向左前进而非退回，故其余项错误。","tier":"进阶"},{"id":281,"type":"single","stem":"调试绷缝机时，发现缝出的线迹背面出现浮线，正面线迹正常，应优先检查","options":["针杆高度是否偏低","弯针勾线时机是否偏早","底线凸轮打线量是否偏小","压脚压力是否偏大"],"answer":[2],"explanation":"背面浮线多因底线（弯针线）打线量不足，线未及时收紧。针杆高度偏低、弯针勾线偏早主要引起跳针；压脚压力偏大影响送料，均不直接导致背面浮线。","tier":"挑战"},{"id":282,"type":"single","stem":"装配缝纫机挑线机构时，挑线杆在最上位置应使挑线量处于什么状态","options":["收线结束并开始放线","放线结束并开始收线","保持收线量最大不变","保持放线量最大不变"],"answer":[1],"explanation":"挑线杆最高点是放线结束、转入收线的转折点，此时应完成放线并开始收线。认为收线结束开始放线是方向反了；保持最大收线或放线量不变则不符合挑线杆往复运动规律。","tier":"进阶"},{"id":283,"type":"single","stem":"装配高速平缝机时，为减少机针与旋梭的磨损，正确的润滑做法是","options":["在旋梭内圈加注黄油后长期使用","用缝纫机油按油路要求供油并定期检查油窗","仅在开机前向针杆滴几滴机油","旋梭部位不加油以免污染缝线"],"answer":[1],"explanation":"高速平缝机应通过油路按规定供油并观察油窗回油情况。旋梭加黄油会阻碍转动；仅针杆滴油不能满足旋梭润滑；旋梭不加油会加速磨损，三者均错误。","tier":"基础"},{"id":284,"type":"single","stem":"某厂装配的平缝机在缝制薄料时线迹良好，换厚料后出现断针，排除机针弯曲后，最可能的原因是","options":["针杆高度偏低使勾线时机滞后","送布牙高度偏低导致送料不畅","旋梭供油量偏大造成线环紊乱","挑线簧张力偏大造成收线过快"],"answer":[0],"explanation":"厚料时机针回升慢，若针杆高度偏低使勾线滞后，机针与旋梭干涉会断针。送布牙偏低影响送料；供油偏大影响润滑；挑线簧张力偏大影响线迹，均不直接造成断针。","tier":"进阶"},{"id":285,"type":"multi","stem":"装配工业缝纫机后需要进行整机调试，下列属于旋梭勾线机构调试内容的有","options":["旋梭梭尖与机针中心的轴向间隙","旋梭梭尖进入机针线环的时机","旋梭内圈与梭架的配合松紧","送布牙露出针板的高度","挑线杆最高点的收线时机"],"answer":[0,1,2],"explanation":"旋梭勾线机构调试包括梭尖与机针的轴向间隙、勾线时机及旋梭与梭架配合。送布牙高度属送布机构；挑线杆收线时机属挑线机构，均不属旋梭勾线调试内容。","tier":"挑战"},{"id":286,"type":"single","stem":"平缝机调试时出现面料背面线迹浮线，而正面线迹正常，最应先检查的部位是","options":["梭皮压簧的压紧程度","挑线簧的弹力大小","针杆的高低位置","压脚的压力大小"],"answer":[0],"explanation":"知识点是梭皮（底线张力）与面线张力的配合。背面浮线说明底线张力过小，应先检查梭皮压簧压紧程度。挑线簧弹力主要影响收线时机，不直接决定底面线张力比；针杆高低影响勾线时机；压脚压力影响送布，均非首要原因。","tier":"进阶"},{"id":287,"type":"single","stem":"装配工业缝纫机的旋梭时，梭尖与机针中心线的轴向间隙应控制为","options":["0.05～0.15mm","0.5～0.8mm","1.0～1.5mm","2.0～2.5mm"],"answer":[0],"explanation":"知识点是旋梭与机针的配合间隙。标准要求梭尖与针中心线轴向间隙约0.05～0.15mm，过大易跳针断线。0.5mm以上间隙过大，勾线不可靠；1.0mm以上严重超差；2.0mm以上属明显装配错误。","tier":"基础"},{"id":288,"type":"single","stem":"包缝机在缝制薄料时出现缝料边缘被切得过宽，正确的调整操作是","options":["调整上刀的压簧压力并微调下刀位置","更换大号机针后重新穿线","调高针杆位置并加大挑线量","降低压脚压力并加快缝速"],"answer":[0],"explanation":"知识点是包缝机切边宽度的调整。切边宽度由上下刀相对位置决定，调整上刀压簧和下刀位置可改变切边量。换大号机针影响穿刺不影响切边宽度；针杆高度和挑线量影响线迹形成；压脚压力和缝速影响送布，均不改变切边宽度。","tier":"基础"},{"id":289,"type":"single","stem":"绷缝机在调试时发现弯针与机针的配合时机不当造成跳针，正确的调整顺序是","options":["先调机针高度，再调弯针前后及左右位置","先调弯针前后位置，再调机针高度","先调弯针左右位置，再调针杆高低","先调压脚高度，再调弯针前后位置"],"answer":[0],"explanation":"知识点是绷缝机勾线配合的调整顺序。应先确定机针高度作为基准，再调整弯针前后及左右位置与机针配合。先调弯针会导致基准丢失；先调弯针左右位置同样缺少基准；压脚高度与勾线时机无关。","tier":"挑战"},{"id":290,"type":"single","stem":"工业缝纫机装配完成后进行空运转试验，运转时间一般应不少于","options":["10分钟","1分钟","30秒","3小时"],"answer":[0],"explanation":"知识点是装配后的空运转试验要求。空运转试验一般不少于10分钟，以检查运转平稳、温升和噪声。1分钟和30秒时间过短无法暴露问题；3小时远超常规试验时长，属过度要求。","tier":"基础"},{"id":291,"type":"single","stem":"装配工业平缝机针杆机构时，针杆下端面与针杆套筒下端面的距离应调整到说明书规定值，若该距离偏小会造成什么后果","options":["针杆上升时挑线杆供线量不足","针杆下降时刺布阻力明显增大","针杆行程变小导致送布牙碰针板","针杆与套筒配合间隙变大产生油污"],"answer":[1],"explanation":"知识点：针杆高度决定机针刺布位置与勾线时机。正确项对：针杆过低使机针下死点过低，刺布阻力增大并易断针。干扰项错：挑线杆供线由挑线凸轮控制，与针杆高度无直接关系；送布牙碰针板由送布牙高度决定；配合间隙由加工精度决定，不会因下端面距离改变而变大。","tier":"进阶"},{"id":292,"type":"single","stem":"调试旋梭勾线时，若旋梭尖与机针的间隙调得过大，最可能引起哪种线迹故障","options":["面线在针孔处频繁断线","底线从梭壳中整圈脱出","勾线时漏勾造成跳针","送布牙啃伤缝料表面"],"answer":[2],"explanation":"知识点：旋梭尖与机针间隙是勾线可靠性的关键。正确项对：间隙过大时梭尖无法稳定进入线环，造成漏勾即跳针。干扰项错：面线断线多因过线部位毛刺或张力过大；底线整圈脱出是梭壳弹簧片压力问题；送布牙啃料是送布牙高度或压力问题。","tier":"进阶"},{"id":293,"type":"single","stem":"缝制薄料时出现面料被送布牙啃出齿痕，调整时优先采取的正确措施是","options":["降低送布牙高度并减小压脚压力","换用大号机针并加大面线张力","把送布牙换成粗齿规格再调快转速","旋松旋梭定位螺钉改变勾线时机"],"answer":[0],"explanation":"知识点：送布牙高度与压脚压力共同决定对薄料的抓取力。正确项对：降低牙高、减小压力可避免齿痕同时保持送布。干扰项错：大号针和加大张力会加剧面料损伤；粗齿牙更易啃料；旋梭定位螺钉影响勾线，与齿痕无关。","tier":"挑战"},{"id":294,"type":"single","stem":"某台包缝机在正常缝速下运转，但一降速到低速就出现针距忽长忽短，最应检查的部位是","options":["主轴上各过线器的瓷眼是否磨损","送布凸轮与主轴的紧固螺钉是否松动","压脚底面的粗糙度是否超差","下弯针的勾线间隙是否偏大"],"answer":[1],"explanation":"知识点：送布凸轮与主轴连接松动会在低速时因惯性小而打滑，造成针距不稳。正确项对：紧固螺钉松动正是低速针距忽长忽短的典型原因。干扰项错：瓷眼磨损影响张力不匀而非针距；压脚粗糙度影响送布阻力；下弯针间隙影响跳针。","tier":"进阶"},{"id":295,"type":"single","stem":"装配绷缝机时，弯针前后运动与机针上下运动的配合时序错误，最直接的判断依据是","options":["弯针在机针下降到下死点前就开始后退","弯针在机针上升形成线环时到达最前位","弯针在最前位停留时间超过主轴半转","弯针退回时与机针针杆发生轻微擦碰"],"answer":[1],"explanation":"知识点：绷缝机弯针应在机针上升形成线环时到达最前位完成勾线。正确项对：此时序是勾线成功的基本条件，偏差即配合时序错误。干扰项错：弯针先于下死点后退属正常提前量；停留时间由凸轮曲线决定并非时序错误判据；轻微擦碰是间隙问题。","tier":"挑战"},{"id":296,"type":"single","stem":"工业缝纫机润滑系统中，油绳式供油装置调试时发现针杆部位供油不足，而油池油位正常，最可能的原因是","options":["油绳端头未插入油池液面以下","回油孔被绒絮堵塞使油位虚高","油泵柱塞行程调得过大","油池内使用了黏度偏低的润滑油"],"answer":[0],"explanation":"知识点：油绳供油依靠毛细作用把油从油池吸到润滑点。正确项对：油绳端头未浸入液面则毛细吸油中断，导致供油不足。干扰项错：回油孔堵塞会使油外溢而非供油不足；柱塞行程过大会供油过量；黏度偏低反而更易流动。","tier":"挑战"},{"id":297,"type":"single","stem":"装配高速平缝机时，挑线杆过线孔与挑线凸轮滚柱的相对位置调错，会导致缝纫中出现哪种现象","options":["面线在挑线杆处周期性松紧突变","底线张力旋钮调节失去作用","针距调节盘刻度与实际不符","压脚提升高度达不到标准值"],"answer":[0],"explanation":"知识点：挑线杆与挑线凸轮滚柱共同控制收放线节奏。正确项对：相对位置错误会破坏收线放线节拍，使面线周期性松紧突变。干扰项错：底线张力由梭壳螺钉决定；针距由送布机构决定；压脚提升高度由压脚机构决定。","tier":"进阶"},{"id":298,"type":"single","stem":"某缝制设备维修人员在排除平缝机断针故障时，发现机针装反且针杆高度偏低，他应先处理哪一步再试机","options":["先更换新旋梭再调整针杆高度","先把机针正确装入针夹再调针杆高度","先调大针距再换粗一号机针","先旋松压脚压力再调送布牙高度"],"answer":[1],"explanation":"知识点：断针排查应先消除装机错误这一前提。正确项对：机针装反会使线环无法正常形成，必须先纠正装针方向再按标准调针杆高度，才能判断其他因素。干扰项错：旋梭无异常就更换属盲目换件；调针距和换粗针不能解决装反问题；压脚与送布牙调整与断针主因无关。","tier":"挑战"},{"id":299,"type":"single","stem":"缝纫车间一台绷缝机在缝制弹性针织料时频繁跳针，检查发现机针型号为圆头针且针杆高度正确，下一步最合理的处置是","options":["把针杆高度再下调半毫米试缝","改用适合针织料的圆头针并核对针号","将旋梭尖与机针间隙调至零接触","把送布牙换成细齿并加大压脚压力"],"answer":[1],"explanation":"知识点：针织料跳针常与机针针尖形状和针号选择有关。正确项对：应确认所用圆头针针号与面料匹配，必要时更换合适针号再试。干扰项错：针杆高度已正确不应再下调；间隙调至零接触会撞针；换细齿牙和加压不解决勾线问题。","tier":"挑战"},{"id":300,"type":"multi","stem":"调试工业平缝机送布机构时，为保证送布平稳且不损伤缝料，下列调整措施中正确的有","options":["送布牙高度按说明书规定值调整","压脚压力随缝料厚度适当增减","送布牙与针板槽的间隙保持均匀","送布凸轮紧固螺钉拧紧后不再复查","送布牙倾斜角度与针板平面平行"],"answer":[0,1,2],"explanation":"知识点：送布机构调整包括牙高、压力、间隙与角度等要素。正确项对：按说明书调牙高、按料厚调压力、保持牙与针板槽间隙均匀都是保证平稳送布的必要措施。干扰项错：紧固螺钉拧紧后仍需复查防松动；送布牙与针板平面并非简单平行关系，角度应按机型规定调整。","tier":"挑战"}]}