液压升降机压力无法卸载的原因？

升降机厂家认为，为了避免活塞在行程两端冲撞缸盖，产生噪声，影响工件精度以至损坏机件，常在天津升降货梯液压泵站系统中液压缸两端设置缓冲装置。其作用是利用油液的节流原理来实现对运动部件的制动。常用的缓冲装置、有环状间隙式、节流口可调式、节流口可变式三种形式。Elevator manufacturers believe that, in order to avoid collision at both ends of the stroke piston cylinder head, noise, impact and precision mechanical damage, often two ends of the hydraulic cylinder buffer device is arranged in Tianjin lifting elevator hydraulic pump station system. Its role is to use the throttle principle of oil to achieve the moving parts of the brake. Commonly used buffer device, the annular gap type, adjustable throttle mouth, three types of variable orifice.

1.环状间隙式：当缓冲柱塞进入与其相配的缸盖上内孔时，液压油必须通过间隙才能排出，使活塞速度降低。升降机厂家分析认为，由于配合间隙不变，故缓冲作用不可调，且随O型圈活塞速度的降低，其缓冲作用逐渐减弱。The annular gap type: when the cylinder head is matched with the buffer plunger into the inner hole, the hydraulic oil must be discharged through the gap to make the piston velocity decrease. Elevator manufacturers believe that, due to the gap with the same, so the buffer can not be adjusted, and with the O ring piston speed reduction, the buffer effect gradually weakened.

2.节流口可调式：当缓冲柱塞进入缸盖上的内孔时，液压油必须经过节流阀才能排出。升降机厂家提醒，由于节流阀是可调的，故缓冲作用也可调，但这种调节是缓冲进行前的调节，在缓冲进行中，缓冲作用仍是固定不变的。The throttle adjustable: when the buffer plunger into the inner hole of the cylinder head, the hydraulic oil must be discharged through the throttle valve. Lift manufacturers to remind, because the throttle valve is adjustable, so the buffer can also be adjusted, but this adjustment is the buffer before the adjustment, in the buffer, the buffer is still fixed.

3.节流口可变式：在活塞的轴向上开有三角沟槽，其过流断面越来越小，缓冲作用随着速度的降低而增强。升降机厂家介绍，缓冲作用均匀，缓冲压力较低，气缸位置精度较高，解决了在行程最后阶段缓冲作用过弱的问题。Variable orifice: in the axial direction of the piston has a triangular groove, the flow cross-section is getting smaller and smaller, buffer with the speed of the increase. Elevator manufacturers, the buffer effect is uniform, the buffer pressure is low, the cylinder position accuracy is high, to solve the problem in the final stage of the buffer is too weak.