Pressure-limiting valve plunger and improved oil pump pressure-limiting valve

Abstract

The invention provides a pressure-limiting valve plunger and meanwhile further provides an improved oil pump pressure-limiting valve. The pressure-limiting valve plunger is of a cylindrical structurewith one end closed, and the cylindrical structure can be divided into two sections according to the difference of the outer diameter, wherein the section close to the closed end is the first section,and the other section is the rear section. The outer diameter of the front section is smaller than that of the rear section, and an outward boss is arranged on the position, close to the closed end,of the front section. The outer diameter of the boss is equal to that of the rear section. The improved oil pump pressure-limiting valve has the main improved point in that the plunger structure. Therear section of the plunger and the boss of the front section are equal in outer diameter, thus the rear section of the plunger and the circumferential face of the boss are in small clearance fit withthe hole wall of a valve hole, in this way, the guiding effect is achieved, and the situation that the plunger is deflected in the valve hole and consequently clamping stagnation is caused is prevented; and it is ensured that when the pressure-limiting valve is in a closed state, the peripheral portion of the end face of the closed end of the plunger can be flatly attached to the step surface, and thus oil sealing is more reliable.

Description

technical field [0001] The invention belongs to the lubricating system of an internal combustion engine, in particular to a plunger of a pressure limiting valve and an improved pressure limiting valve of an oil pump. Background technique [0002] The oil pump is an important part of the lubrication system. Its function is to provide sufficient pressure and flow of oil for the lubrication system. The oil pressure must be within a certain range to ensure that each friction part is fully lubricated and does not damage the relevant bearings. pressed pieces. [0003] The oil pump pressure limiting valve plays the role of controlling the oil flow and adjusting the oil pressure during the operation of the oil pump, including the valve hole and the plunger, spring and screw plug installed in the valve hole. The plunger of the traditional oil pump pressure limiting valve adopts a cylindrical structure with one end closed, and there is a small gap between the circumferential surface ...

AI Technical Summary

Problems solved by technology

[0004] In the actual use process, the pressure limiting valve of the oil pump has the following deficiencies: 1. There are sharp burrs on the circumferential surface of the plunger; 2. There are machined aluminum scraps on the valve hole wall; 3. There are impurities in the oil

These situations are likely to cause the risk of stagnation between the circumferential surface of the plunger and the wall of the valve hole, making the plunger unable to move axially smoothly, resulting in the oil pump pressure limiting valve not being able to open or close normally, causing the outlet oil of the oil pump to If the pressure adjustment lags behind or the ability of the plunger to seal oil is reduced, it will greatly affect the reliability of the engine lubrication system. In serious cases, the plunger may even be stuck and cannot be closed, causing all the oil at the pump outlet to leak out, and the main channel of the engine to burn without lubrication. die

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