Engine and pressure limiting valve thereof

Abstract

The invention discloses a pressure limiting valve of an engine. The pressure limiting valve of the engine comprises a valve body, a valve element and a spring, wherein the valve element and the spring are arranged in the valve body; the valve element is in sliding fit with the valve body through the spring; the valve body is provided with an oil discharging hole and an oil feeding hole; the oil feeding hole and the oil discharging hole are connected with each other while the spring is compressed and are disconnected from each other while the spring recovers; the spring is a variable-stiffness spring; and the stiffness of one end, which is close to the valve element, of the variable-stiffness spring is smaller than that of the other end, which is far away from the valve element, of the variable-stiffness spring. Because the spring is the variable-stiffness spring, the stiffness of the side, which is close to the valve element, of the spring is small; when the pressure of a main oil gallery fluctuates, the recovery speed of the valve element is reduced, fluctuation of the valve element due to high stiffness of the inside of the valve body is effectively restrained, and a phenomenon that the spring and the engine naturally vibrate, so that resonance is caused, and the spring is broken is avoided; the service life of the spring is greatly prolonged; and the working reliability of the pressure limiting valve is improved. The invention also provides an engine comprising the pressure limiting valve.

Description

technical field [0001] The invention relates to the technical field of automobiles, in particular to an engine and a pressure limiting valve thereof. Background technique [0002] The pressure-limiting valve is installed in the lubricating oil circuit of the engine. When the oil pressure is higher than the opening pressure of the pressure-limiting valve, the pressure-limiting valve will open to release part of the lubricating oil, so that the oil pressure of the diesel engine will remain balanced and will not be too high. [0003] The pressure limiting valve generally includes a valve body, a valve core and a valve seat, and the valve core is slidably connected to the inside of the valve body through a spring. When the oil pressure in the main oil passage of the engine is too high, the lubricating oil pressure pushes the spool to move forward, and then pushes the spring to compress, and the main oil passage of the engine communicates with the oil drain hole, so that excess l...

AI Technical Summary

Problems solved by technology

[0004] In the prior art, the above-mentioned springs usually adopt equal stiffness springs. During the working process, when the valve core is opened, as the displacement of the valve core increases, the spring force overcome increases rapidly. When the elastic force of the spring is greater than the liquid pressure, the valve core quickly returns Repeatedly, the vibration of the valve core is large, and the natural vibration frequency of the spring and the engine is prone to resonance, which will cause the spring to break, the pressure limiting valve to fail, and there are potential safety hazards

Images