普通车床的液压卡盘或专用车床上的液压夹具,其作用是自动、快速夹紧和松开工件。为此就往往要求在车床主轴箱的尾部装一套特殊的拉紧用油缸,以使卡盘或车夹具能得到从拉棒所传来的松、夹原动力。图示为一种车床用的拉紧油缸(拉棒和卡盘或夹具的连接部分来画出)。运动过程如下:当压力油进入油缸前腔,活塞向后移动时,通过活塞杆的后端顶动前平面轴承和拉力座,拉力座和拉 Hydraulic lathe on an ordinary lathe or a hydraulic fixture on a special lathe, the function of which is to automatically and quickly clamp and release the workpiece. To this end, it is often required to install a special tightening cylinder at the tail of the lathe headstock, so that the chuck or the car jig can obtain the loose power and the motive power from the pull rod. Shown is a tightening cylinder for lathes (drawbar and chuck or jig connection). Movement process is as follows: When the pressure oil into the cylinder before the cavity, the piston moves backwards, through the rear end of the piston rod moving the front plane bearing and tension seat, tension seat and pull