A threaded cartridge load holding valve

Abstract

The invention belongs to the technical field of hydraulic components. The invention discloses a threaded plug-in load holding valve. The valve body is provided with an oil inlet, an oil outlet, a control oil port and an oil discharge port; The lower end of the valve seat is in sealing contact with the one-way valve core; the flow control valve core is located inside the valve seat and can move axially relative to the valve seat; the lower end of the valve seat is provided with an axial hole, and the lower end of the flow control valve core is sealed with the axial hole contact; the flow control spool and the valve seat form a control cavity, and there is a first spring in the control cavity to generate a pressing force on the flow control spool; the flow control spool is provided with a valve hole and a damping hole, and the damping hole and the oil outlet It communicates with the valve hole, and the valve hole is communicated with the oil discharge port and the control cavity; the upper end of the pilot spool and the valve body form a control oil cavity and communicate with the control oil port, and the lower end is in sealing contact with the valve hole. The threaded cartridge load holding valve of the present invention is easy to integrate, has a long service life, and has a safety overflow function and fretting performance.

Description

technical field [0001] The invention belongs to the technical field of hydraulic components, and in particular relates to a threaded cartridge type load holding valve. Background technique [0002] In the field of construction machinery and construction machinery, many equipment such as excavators, loaders, and two-headed excavators rely on oil cylinders to bear loads, so oil cylinders are required to have a load holding function. However, the action control of the oil cylinder mainly relies on the valve, and the valve usually has the problem of oil leakage during work. In this way, when the weight of the oil cylinder is heavier, the leakage of the oil cylinder will increase, which will lead to its working process. The load holding performance will be worse. [0003] In order to solve the impact on the load holding performance of the oil cylinder due to the valve leakage problem, in the Chinese patent with the application number 201510193345.8 named load holding valve and t...

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Problems solved by technology

[0004] However, the load holding valves disclosed in the above two patents have the following technical problems: 1. They are all plate valve structures, so they need to be fixedly installed on the bracket with screws during actual use, and then pass through the pipeline and oil cylinder and multiple valves. 2. When controlling the lifting and lowering of the oil cylinder, the load holding valves disclosed in the above two patents are both It is realized by controlling the repeated opening and closing actions of a spool, and the frequent operation of construction machinery will increase the opening and closing times of the corresponding spool, thereby aggravating the wear of the spool, resulting in poor sealing and leakage , which ultimately leads to shortened service life of the entire valve; 3. When the oil cylinder is in a long-term static state and the pressure in the oil cylinder rises due to the rise in oil temperature, the load holding valves disclosed in the above two patents cannot realize the increase in oil pressure. High limiting effect, at this time, in order to prevent the oil cylinder seal ring and pipeline from being damaged due to the continuous increase of oil pressure, it is usually necessary to configure a separate safety valve, which not only increases the complexity of the equipment, but also increases the cost of the equipment

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