Pressure-stabilizing pilot-operated type overflow valve

Abstract

The invention discloses a pressure-stabilizing pilot-operated type overflow valve which comprises a valve body, a valve cover is fixedly mounted at the upper end of the valve body through a bolt, an adjusting screw is arranged at one end of the valve deck in a penetrating manner, a hand wheel is fixedly mounted at one end of the adjusting screw rod, and a screw protection device is fixedly mountedat a connecting position of the valve cover and the adjusting screw. The other end of the adjusting screw penetrates through the valve cover and is fixedly provided with a pressure adjusting spring,a cone valve is fixedly mounted at one end of the pressure adjusting spring, a cone valve seat is arranged in a position, close to the cone valve, in the valve cover, and a main valve spring is arranged in a position, close to the valve cover, of the upper end in the valve body. By arranging the screw protection device, under a condition that the adjusting screw is frozen, the connecting positionof the adjusting screw and the connecting thread can be heated through a heating plate to melt an ice layer, and the problem that when a hand wheel is needed for adjustment, it is prone to damage theadjusting screw and the connecting thread inside to lead to damage of the equipment is solved.

Description

technical field [0001] The invention relates to the technical field of valve equipment, in particular to a pressure-stabilizing pilot relief valve. Background technique [0002] Relief valves are divided into direct-acting relief valves and pilot-operated relief valves. The direct-acting relief valves are directly opened and closed by comparing the hydraulic pressure with the spring force. When the fluid pressure is high, the spring stiffness is also required. Larger, but when the spring stiffness is larger or the spring is thicker, its control performance will be worse, so the direct-acting relief valve is generally only used in low-pressure systems with small flow, and the pilot relief valve consists of the main valve and the pilot Valve composition, when the hydraulic pressure is greater than the pressure regulating spring force of the pilot valve, the valve port opens to form an overflow circuit, and the pressure drop is generated due to the damping hole on the main valv...

AI Technical Summary

Problems solved by technology

[0003] In the process of realizing the present invention, the inventor found that at least the following problems in the prior art have not been solved: 1. When the overflow valve in the prior art is used in the cold outdoor environment in winter in the north, the handwheel and the adjusting screw will be damaged due to Rain and snow cause freezing. When the handwheel needs to be used for adjustment, it is easy to damage the connecting thread between the adjusting screw and the inside, resulting in equipment damage. At the same time, there is no protective device at the connection position between the adjusting screw and the valve. The threaded rod will enter the valve. Since the external threaded rod is exposed to the air during use, it will be contaminated with dust. When the external threaded rod enters the valve during adjustment, the hydraulic oil in the valve will be polluted, which is easy to cause damping The hole blockage produces irregular pressure changes, which cannot be adjusted well and affects the normal use of the relief valve; 2. During the working process of the hydraulic system, the wear and tear of various parts will inevitably produce some pollutants, which will mix In the hydraulic oil, when the hydraulic oil passes through the damping hole, the damping hole is too large, and the pollutants enter the driving chamber of the main valve core through the damping hole, causing the main valve core to stick, or entering the valve seat of the pilot valve assembly, causing the pilot valve core to close. Undead, the damping hole of the main spool is too small and easy to be blocked, so in the existing hydraulic components and hydraulic systems, the failure rate of the overflow valve accounts for more than 50% of the total failure rate, blindly pursuing the cleanliness of the hydraulic oil And reduce processing burrs, undoubtedly greatly improve the system cost

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