英国汽车制品公司研制了一种汽车中央门锁系统用的简易真空促动器。该促动器现处于试制阶段,一些汽车厂正在进行使用评价。据称,其主要优点是生产成本低、重量轻,动作迅速而且无噪声。该装置主要由五个塑料模压件构成,为了装配方便,这些零件被设计成扣合在一起的。壳体的两个圆筒形气室中,一对对置柱塞由旋转式膜片封闭,壳体由注塑出的隔板从中间分开。上柱塞(假定垂直安装)使锁销与贯穿直径的径向槽接合。上部气室被抽空时,拉下锁销,就会关闭门锁。真空消失时,一个内弹簧使柱塞返回中间位置,而并不移动锁销。下柱塞以相似动作松开门锁,它与一个矩形钢丝框连接,此钢丝框环绕在壳体周围,并穿过上柱塞上与第一个槽径向偏斜的第二个槽。向内行程时,钢丝框顶起锁销,然后借助一个回位弹簧使柱塞回位。 British automotive products company developed a simple central vacuum lock system for automotive actuators. The actuator is now in the trial stage, and some automobile factories are using the evaluation. Allegedly, its main advantage is the low cost of production, light weight, fast and noise-free operation. The device is mainly composed of five plastic molded parts, which are designed to snap together for ease of assembly. Of the two cylindrical gas cells of the housing, a pair of opposed pistons are enclosed by a rotary diaphragm, and the housing is separated from the middle by an injection molded partition. The upper plunger (assumed to be mounted vertically) engages the locking pin with the radial through-slot. When the upper chamber is evacuated, the latch is pulled and the door lock is closed. When the vacuum disappears, an inner spring returns the plunger to the neutral position without moving the lock pin. The lower plunger releases the door lock in a similar manner, which is connected to a rectangular wire frame that surrounds the housing and passes through a second slot in the upper plunger that is radially offset from the first slot. In the inward stroke, the wire frame jacks up the lock pin and returns the plunger with a return spring.