SU260863A1 - HYDRAULIC JACK - Google Patents

Description

This invention relates to lifting mechanisms.

Hydraulic jacks are known that contain a stationary cylinder with a piston, an injection cavity and a base plate, a double-plunger pump with a pinion drive, an oil tank and a hoisted paw fixed on a movable cylinder. Such jacks have constant performance, which does not depend on the weight of the load. At the same time, when using jacks that lift onto a paw and head, loads of different weights are lifted.

The purpose of the invention is to increase labor productivity at optimum operating conditions of the jack.

This is achieved by the fact that in the upper part of the jack there is an additional injection cavity, connected with an oil tank with a check valve and with a pressure line with a control valve, which operates depending on the weight of the load being lifted. In addition, the control valve is made in the form of a sleeve with a spring-loaded spool having a conical part and a guide, provided with longitudinal grooves for the passage of fluid in the process of opening the valve.

A-A cut in FIG. one; in fig. 3 is a section along BB in FIG. 2: in FIG. 4 shows a section along BB in FIG. 1. The jack contains plt support /, hard

fixed cylinder fixed to the plate

2, movable cylinder 3, rigidly connected with

panel 4, which is installed oily

tank 5 with a cargo head 6.

In a stationary cylinder 2, throttle piston 7, rigidly connected to the panel with a 4 tube 8. On the tube, provide a height limiter 9 for lifting the load. In the upper part 1 of the cylinder 2, the guide ring 10 is coiled by a thread. A spring // is placed between the piston 7 and the ring 10, which returns the moving parts of the cylinder after lifting the load to its original position.

At the top of the panel there are two plunger pumps. Each pump consists of

body 12, sleeves 13, plunger 14, suction 15 and discharge 16 valves. Pump connectors are driven by a pump 77, which sits on a shaft 18 rigidly connected to the handle 19.

The plunger pumps of the drilling system are connected to the discharge line, which is permanently connected to the strip G by means of a control valve consisting of a sleeve 20 and a spool 21, made with a digger, having longitudinal grooves for the passage of fluid with the valve open, with a cavity D The spool is spring-loaded by a spring 22, the compression of which is regulated by a screw 23.

In addition, a check valve 24 is placed in the panel, through which, when released, the working fluid from the oil tank enters cavity D, and two drain valves 25 and 26 and a safety valve. The valve 25 bypasses the oil in the drilling system from the cavity D to the oil tank, and the valve 26 from the cavity G. The safety valve consists of a ball 27, a seat 28 and a spring 29 (see Fig. 4).

To lift the rails and low-lying loads on the node cylinder 3, a paw 30 is mounted on the threads.

The jack works as follows.

When lifting loads, for example, weighing no more than 0.4 of maximum capacity, when the pressure of the fluid in the discharge line does not exceed the critical pressure to which the control valve is set, from the handle 19 the plungers 14 are brought into reciprocating motion and pressure enters the cavity D and raises the load to the required height. The control valve is closed at the same time, and the working fluid from the discharge line is not nostunaag into the cavity D. However, since the oil tank 5 together with the movable cylinder 3 and the piston 7 rises, a vacuum is created in the cavity D, under the action of which the check valve 24 opens, and the working fluid from the oil tank enters this cavity.

When the load is lowered to the initial position, the drain valves 25 and 26 are opened, and the oil is forced by the forces of the spring 11 compressed when the load is lifted and the weight of the load itself from the cavities D and D is displaced into the oil tank.

and the moving parts of the jack are returned to their original position.

The presence of two injection cavities and two drain valves significantly increases the reliability of fixation of the lifted load, since with one valve open, the second cavity acts as a hydraulic block, as a result, lowering the load is impossible.

When lifting loads, for example, weighing more than

0.4 maximum loading capacity; the pressure in the discharge line is higher than the pressure to which the control valve is set, and the working fluid, which is pumped by the pump, compresses the spring 22 and moves the spool 21.

The working fluid begins to flow simultaneously into both cavities, the jack carrying capacity increases dramatically, and the lifting speed of the loads decreases. The load is lowered in the same way as described above.

Subject invention

Claims (2)

1.Hydraulic jack containing a stationary cylinder with a piston, a pressure chamber and an onorite silo, a two-piston pump with a rack and pinion actuator, an oil tank and a lifting foot attached to the base cylinder, characterized in that At the optimal operating conditions of the jack, in the upper part of it, there is an additional injection cavity connected to the oil tank, non-return valve and to the discharge line by a control valve that operates depending on the weight of the lifted load. 2. The jack according to claim 1, characterized in that the control valve is designed as a sleeve with a spring-loaded spool having a conical part and a guide provided with longitudinal grooves for the passage of fluid in the process of opening the valve. c 1 lU "3 ......... l .......................  KXjvXXXXXXXXXXXXX . Y X v4 ± a: jMjijia . - @ / 0 E fe // 0-b fe 26