Piston rod oil inlet double-action multi-stage hydraulic cylinder

Abstract

The invention discloses a piston rod oil inlet double-action multi-stage hydraulic cylinder, and relates to the field of hydraulic cylinders. The piston rod oil inlet double-action multi-stage hydraulic cylinder comprises a cylinder body, at least two stages of piston rod assemblies arranged in the cylinder body in a sleeving mode stage by stage, multiple one-way valve assemblies, an ejection roddevice and a balancing valve assembly; each piston rod assembly comprises a piston and a piston rod; each one-way valve assembly comprises an in-cylinder one-way valve used for controlling rod cavities of the corresponding adjacent two stages of piston rod assemblies to communicate with each other or be intercepted; the ejection rod device is used for driving the in-cylinder one-way valves to be opened or closed, when the pistons in every two adjacent stages of the piston rod assemblies are separated in the stretching or retracting process, the ejection rod device is self-locked; and when thepistons in every two adjacent stages of the piston rod assemblies make contact with each other in the stretching or retracting process, the ejection rod device drives the in-cylinder one-way valves tobe opened; and the balancing valve assembly is fixed to the piston rod of the lowest stage of the piston rod assembly. According to the piston rod oil inlet double-action multi-stage hydraulic cylinder, the problem that a sealing ring is prone to being worn due to the fact that a traditional multi-stage hydraulic cylinder adopts radial holes can be solved, internal leakage of the hydraulic cylinder is avoided, and it is guaranteed that each stage of a hydraulic cylinder body can not generate the overpressure phenomenon.

Description

technical field [0001] The invention relates to the field of hydraulic cylinders, in particular to a piston rod oil-intake double-acting multistage hydraulic cylinder. Background technique [0002] On hydraulic engineering machinery or large hydraulic equipment, due to the limitation of installation space and the complex and changeable load, it is usually necessary to use multi-stage hydraulic cylinders and work under alternating loads. Ordinary multi-stage hydraulic cylinders generally adopt a structure with radial holes in the cylinder barrel in order to ensure the expansion and contraction sequence of the hydraulic cylinder. This structure is widely used in construction machinery with low requirements. Since the diameter of the radial hole of the cylinder must be smaller than the width of the piston seal ring, usually not less than 2mm, in order to ensure the flow area, it is necessary to distribute a large number evenly along the radial direction, and the diameter of the...

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Problems solved by technology

[0004] In view of the defects existing in the prior art, the object of the present invention is to provide a double-acting multi-stage hydraulic cylinder with piston rod feeding oil, which can effectively solve the problem that the double-acting multi-stage hydraulic cylinder cannot work normally under alternating loads, and the traditional The multi-stage hydraulic cylinder adopts the radial hole to cause the seal ring to be easily worn, avoiding the internal leakage of the hydraulic cylinder, and the hydraulic cylinder to be easily over-pressurized caused by the use of ordinary stroke valves and other pressure regulating valves, ensuring that each stage None of the hydraulic cylinders will be over-pressurized

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