Excavator load holding valve

Abstract

The invention relates to an excavator load holding valve, which comprises a valve sleeve, which is provided with a first oil port and a second oil port; a screw sleeve, which is threadedly connected to the upper end of the valve sleeve; and a valve seat, which is fixedly connected in the valve sleeve; The one-way valve core is slidingly arranged in the valve sleeve, and has an inner tapered surface to form a line seal with the lower end surface of the valve seat; the adjustment sleeve is threaded on the screw sleeve; the overflow valve seat is fixedly connected to the lower end of the adjustment sleeve; the control The spool, slides in the valve seat; the control spring; the relief valve assembly. The excavator load holding valve of the present invention has the advantages of simple structure, compact volume, convenient integration, long service life and safety overflow function.

Description

technical field [0001] The invention belongs to the technical field of excavators, in particular to an excavator load holding valve. Background technique [0002] The load holding system is an essential hydraulic system in the hydraulic system of the excavator. It is used to ensure that the excavator can maintain a certain action for a long time, such as the maintenance of the stick and the boom in the excavator. It can ensure that the excavator can complete some basic functions. lifting operations. The load holding valve is the most critical part of the load holding system, and its quality directly affects the quality of the excavator's hoisting operation, and even threatens the personal safety of the staff. Therefore, the quality of the load holding valve will directly affect the performance of the load holding system. However, the load holding valve we use currently has a certain internal leakage and the internal leakage is relatively large. This large amount of intern...

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Problems solved by technology

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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