Pressure-adjustable high-pressure limiting valve for common rail

Abstract

The invention discloses a pressure-adjustable high-pressure limiting valve for the common rail. The pressure-adjustable high-pressure limiting valve comprises a valve body, a valve element, a nut, a spring base, a spring and an adjusting bolt, wherein the valve body is provided with a hole A 7 and a hole B 8 which communicate with each other, the valve element is arranged in the valve body and obstructs communication between the hole A 7 and the hole B 8, the nut is arranged on the valve body in a sleeve mode to form a closed valve cavity, the spring base is arranged in the valve cavity, the lower end of the spring base is connected with the valve element, the adjusting bolt is screwed into the nut from the top, and the spring is connected between the adjusting bolt and the spring base inan abutting mode so that the pre-tightening force of the spring on the valve element can be adjusted by rotating the adjusting bolt. According to the pressure-adjustable high-pressure limiting valve,the opening pressure of the high-pressure limiting valve is adjustable, and the adjustable range of the opening pressure and the adjustable range of the pressure relief flow are expanded.

Description

technical field [0001] The invention relates to the related technical field of fuel systems such as fuel oil, natural gas and methanol for high-pressure common rail, and in particular to a high-pressure limiting valve for common rail with adjustable pressure. Background technique [0002] see figure 1 , The existing high-pressure limiting valve components for the common rail system use a one-way safety valve structure, and the pressure is released through the ball valve 19 to achieve the purpose of protecting the safety of the system. The high-pressure fuel enters the valve cavity 9 through the A hole 7 on the valve seat 18. When the system pressure is greater than the opening pressure of the ball valve 19, the ball valve 19 opens and pushes the valve core 2 to move to the rear end, and the fuel leaks from the B hole 8 back to the low-pressure pipe way to realize the pressure relief function. This structure adjusts the opening pressure by adjusting the thickness of the adj...

AI Technical Summary

Problems solved by technology

This structure adjusts the opening pressure by adjusting the thickness of the adjusting gasket 17, which has the disadvantage that after the opening pressure adjustment is completed, the valve body 1 and the valve seat 18 need to be riveted together, that is to say, this structure can only be preset before leaving the factory. The opening pressure cannot be flexibly adjusted during use

This traditional structure no longer meets the requirements of the common rail low rail pressure system, which requires a wide range of opening pressure, limit pressure, and large adjustable range of leakage flow.

[0003] It can be seen that the above-mentioned existing common rail system with high-pressure limiting valve obviously still has inconvenience and defects in structure and use, and needs to be further improved urgently.

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