当摇臂上升到所需位置时，松开按钮SB3，接触器KM2和时间继电器KT1同时断电释放，摇臂升降电动机M2停转，摇臂停止上升。由于KT1释放，其延时闭合的动断触点经1-3秒延时后闭合，接触器KM5的线圈经线路通电吸合，液压电动机M3反向起动旋转，供给压力油。压力油经分配阀进入摇臂夹紧油腔，向相反方向推动活塞，使摇臂夹紧。同时，活塞杆通过弹簧片压下限位开关SQ2动断触点断开，接触器KM5断电释放，液压泵电动机M3停止旋转，完成了摇臂的松开－上升－夹紧动作。
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10、当将SA2扳到左侧时，立柱松开或夹紧。SA2在中间位置按下SB5或SB6时，主轴箱和主柱一起进行夹紧或放松。其他动作过程和主轴箱松开和夹紧完全相同，不再重复。
钻床为孔加工机床，主要用来加工外形较复杂，没有对称回转轴线的工件上的孔。如钻孔、镗孔、铰孔及攻螺纹。因此要求钻床的主轴运动和进给运动有较宽的调速范围。Z3040型摇臂钻床的主轴的调速范围为50:1，正转最低转速为40 r/min，最高为2000 r/min，进给范围为0.05～1.60 r/min。它的调速是通过三相交流异步电动机和变速箱来实现的。也有的是采用多速异步电动机拖动，这样做才能够简化变速机构。钻床按其结构型式不同，有立式钻床、卧式钻床、深孔钻床、多轴钻床及摇臂钻床等。摇臂钻床适合于在大、中型零件上进行钻孔、扩孔、铰孔及攻螺纹等工作，在具有工艺装备的条件下还能够直接进行镗孔。Z3040型摇臂钻床的结构如下所示。
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摇臂钻床的主轴旋转运动和进给运动由一台交流异步电动机拖动，主轴的正反向旋转运动是通过机械转换实现的。故主电动机只有一个旋转方向。摇臂的上升、下降由一台交流异步电动机拖动。主轴箱、立柱的夹紧和放松由另一台交流电动机拖动。通过电动机拖动一台齿轮泵，供给夹紧装置所需要的压力油。而摇臂的回转和主轴箱的左右移动一般会用手动。除此以外还有一台冷却泵电动机对加工的刀具进行冷却。
2.1. Z3040控制线为单方向旋转，由接触器KM1控制，主轴的正反转则由机床液压系统操纵机构配合正反转摩擦离合器实现，并由热继电器FR1作电动机长期过载保护。
2． M2由正、反转接触器KM2、KM3控制实现正反转。控制电路保证，在操纵摇臂升降时，首先使液压泵电动机起动旋转，供出压力油，经液压系统将摇臂松开，然后才使电动机M2 起动，拖动摇臂上升或下降。当移动到位后，保证M2先停下，再自动通过液压系统将摇臂夹紧，最后液压泵电机才停下。M2为短时工作，不设长期过载保护。
9、主轴箱的松开和夹紧为的动作过程：首先将组合开关SA2扳向右侧。当要主轴箱松开时，按下按钮SB5，经1～3s后，液压泵电动机正转使压力油经分配阀进入主轴箱液压缸，推动活塞使主轴箱放松。主轴箱和立柱松开指示灯HL2亮。当要主轴箱夹紧时，按下按钮SB6，经1～3s后，液压泵电动机反转，压力油经分配阀进入主轴箱液压缸，推动活塞使主轴箱夹紧。同时指示灯HL3亮， HL2灭，指示主轴箱与立柱夹紧。
1、主要控制电器为四台电机：主电动机、摇臂升降电动机、液压泵电动Байду номын сангаас、冷却泵电机。
2、主电动机和液压泵电机采用热继电器进行过载保护，摇臂升降电动机、冷却泵电机均为短时工作，不设过载保护。
3、摇臂的升降，主轴箱、立柱的夹紧放松都要求拖动摇臂升降电动机、液压泵电动机能够正反转。
4、摇臂的升降控制：按下摇臂上升起动按钮，液压泵电动机起动供给压力油，经分配阀体进入摇臂的松开油腔，推动活塞使摇臂松开。同时摇臂升降电动机旋转使摇臂上升。如果摇臂没有松开，摇臂升降电动机不能转动，一定要保证了只有摇臂的可靠松开后方可使摇臂上升或下降，可使用限位开关控制。当摇臂上升到所需要的位置时，松开摇臂上升起动按钮，升降电动机断电，摇臂停止上升。当持续1~3s后，液压泵电动机反转，使压力油经分配阀进入的夹紧液压腔，摇臂夹紧，同时液压泵电动机停止，完成了摇臂的松开—上升—夹紧动作。
3．M3由接触器KM4、KM5实现正反转控制，并有热继电器FR2作长期过载保护。
由变压器TC将380V交流电压降为110V，作为控制电源。指示灯电源为 6V。
按下起动按钮SB2，接触器KM1吸合并自锁，主轴电动机M1起动并运转。按下停止按钮SB8，接触器KM1释放，主轴电动机M1停转。
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2、学以致用，巩固书本知识。使初步具有设计电气控制装置的能力。从而培养和提高独立工作的能力和创造能力。
3．进行一次工程技术设计的基本训练。培养查阅书籍、参考资料、产品手册、工具书的能力；上网查寻信息的能力；运用计算机进行工程绘图的能力；编制技术文件的能力等等。
5、摇臂升降电动机的正转与反转不能一起进行，否则将造成电源两相间的短路。
8、立柱和主轴箱的松开与夹紧控制：主轴箱与立柱的松开及夹紧控制可以单独进行，也可以一起进行。由开关SA2和按钮SB5（或SB6）来控制。SA2有三个位置：在中间位置（零位）时为松开及夹紧控制一起进行，扳到左边位置时为立柱的夹紧或放松，扳到右边位置时为主轴箱的夹紧或放松。SB5是主轴箱和立柱的松开按钮，SB6为主轴箱和立柱的夹紧按钮。
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按上升按钮SB3，时间继电器KT1得电吸合，瞬时动合触点闭合，接触器KM4得电吸合，液压泵电动机M3接通电源正向旋转，供给压力油。压力油经分配阀体进入摇臂松开的油腔，推动活塞，使摇臂松开。当摇臂完全松开后，活塞杆通过弹簧片压下限位开关SQ2，使其动断触点SQ2断开，使接触器KM4线圈断电释放，液压泵电动机M3停转，与此同时，另一动合触点SQ2闭合，接触器KM2线圈通电吸合，其主触点接通升降电动机M2的电源，M2启动正向旋转，带动摇臂上升。
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Z3040摇臂钻床主要由底座、内立柱、外立柱、摇臂、主轴箱、工作台等部分所组成，内立柱固定在底座上，在它的外面套着空心的外立柱，外立柱可绕着内立柱回转。主轴箱是一个复合部件，它包括主轴及主轴旋转和进给运动的全部传动变速和操作机构。主轴箱安装于摇臂的水平导轨上，能够最终靠手作使其在水平导轨上沿摇臂移动。
钻削加工时，主轴箱可由夹紧装置将其固定在摇臂的水平导轨上，外立柱紧固在内立柱上，摇臂紧固在外立柱上，接着进行钻削加工。
3、辅助运动：摇臂可沿外立柱的圆柱面上下垂直调整位置；主轴箱可沿摇臂的导轨横向调整位置；摇臂及外立柱绕内立柱转动至不同的位置；工作时可以很方便的调整主轴的位置（工件不动）。后两者为手动，另外还需考虑主轴箱、摇臂、内外立柱的夹紧和松开。
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