Multi-stage hydraulic cylinder

Abstract

The invention discloses a check valve with a push rod and a multi-stage hydraulic cylinder. The check valve with the push rod comprises the push rod (41). The push rod (41) is inserted into a valve cavity from a forward port (P) and is used for operably forwardly opening the valve cavity. The multi-stage hydraulic cylinder comprises N stages of cylinder barrels and a piston rod piece (3), the N stages of cylinder barrels are arranged from the outside to the inside, each stage of cylinder barrel comprises a bottom and a barrel, N rod cavities are formed among the piston rod piece and the various stages of barrels along the radial direction of the hydraulic cylinder, and N axial rodless cavities are formed among the piston rod piece and the various stages of bottoms; a rodless cavity oil port (A) is formed in an outer cylinder barrel (1), the piston rod piece is provided with a piston rod inner cavity (X) and a piston rod inner cavity oil port (C), the bottom of a middle cylinder barrel (2) is used as a middle cylinder barrel piston, and check valves with push rods and protruded trigger portions (5) are arranged at the various bottoms, so that each two adjacent rodless cavities can be opened or closed by the corresponding check valves with the push rods and the corresponding protruded trigger portions (5). The check valve and the multi-stage hydraulic cylinder have the advantages that primary thrust of the multi-stage hydraulic cylinder can be maximized, and the check valve and the multi-stage hydraulic cylinder are applicable to driving different grades of loads to work under complicated working conditions.

Description

technical field [0001] The invention relates to a multi-stage telescopic hydraulic cylinder. Background technique [0002] Such as figure 1 Shown is an existing common multi-stage hydraulic cylinder, which mainly includes a piston rod 3, a guide sleeve 7, an outer cylinder 1 and a middle cylinder 2, and the middle cylinder 2 consists of an inner rod 2' and an outer rod 2 "Composition, its two ends are sealed and welded, and the outer cylinder rodless cavity E is formed between the bottom end of the piston rod 3 and the middle cylinder 2 (formed as a ring surface with different diameters) and the bottom end of the outer cylinder 1. The outer cylinder has a rod cavity Y formed between the radially outermost middle cylinder 2 and the outer cylinder 1. There are two oil holes a and b on the outer cylinder. By controlling the oil in and out of the a and b oil ports The oil cylinder is telescopically controlled by hydraulic pressure. The outer cylinder has a rod cavity Y and eac...

AI Technical Summary

Problems solved by technology

Since the cylinder force F=P*S (P is the hydraulic pressure, S is the area of ​​the rodless cavity), the area of ​​the rodless cavity of the outer cylinder is larger than the area of ​​the pistons at all levels, so the cylinder is subject to its own design under the condition of a certain volume and shape. Due to the limitation of the load, the output is small, it is difficult to exert the maximum force to drive the load, and it is impossible to complete the work with relatively large load resistance.

Moreover, due to design restrictions, this multi-stage hydraulic cylinder can only bear one stage of load, which cannot meet the requirements of complex mechanisms.

For example, under multi-stage load pressure conditions, it is difficult for this multi-stage hydraulic cylinder to control the corresponding piston extension

[0005] In addition, if figure 1 As shown, the multi-stage oil cylinder is only provided with two oil ports in and out, and the expansion and contraction of the oil cylinder is controlled through the two oil ports, without considering safety measures, so it is prone to failure and even the system cannot work normally. Disturbance occurs, resulting in blockage of the oil circuit, or other accidents that cause system pressure overload, and this design does not have any safety pressure relief device, which will cause system failure and paralysis and cause serious losses

And frequent overload will cause the working pressure of the system to be unstable, sometimes high and sometimes low, and even cause the oil cylinder and the system to be overloaded, and the strength and sealing will be affected, resulting in leakage of the oil cylinder, which will also seriously affect the service life of the oil cylinder and other equipment

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