Valve assembly for controlling gas pressure, fuel system comprising valve assembly for controlling gas pressure

Abstract

The invention relates to a valve assembly for controlling the gas pressure in a gas rail of a fuel system for supplying an internal combustion engine with a gaseous fuel, in particular with natural gas, comprising a first valve for connecting the gas rail to a gas feed, a second valve for connecting the gas rail to a gas return, and a control piston for actuating both valves, wherein the control piston delimits a control chamber, to which a hydraulic pressure medium can be applied by a pressure medium feed and which can be depressurized via a pressure medium discharge, and further comprising asealing element which is designed as a corrugated or folding bellows and is arranged between a gas chamber and a pressure medium chamber for media separation. The valve assembly is characterized by apressure differential limiting valve having a reciprocating piston which, on the one hand, is acted upon by a pressure prevailing in the gas chamber and which, on the other hand, is acted upon by a pressure prevailing in the pressure medium chamber, and which opens an additional gas return when a predetermined pressure differential applied to the piston is exceeded. The invention further relatesto a fuel system comprising a valve assembly according to the invention for controlling the gas pressure in a gas rail.

Description

technical field [0001] The invention relates to a valve assembly for regulating the gas pressure in a gas rail of a fuel system for supplying an internal combustion engine with a gaseous fuel, in particular natural gas. Furthermore, the invention relates to a fuel system for supplying a combustion engine with a gaseous fuel, in particular natural gas, comprising such a valve assembly. Background technique [0002] Laid-open publication DE 10 2016 207 743 A1 discloses a fuel system for supplying an internal combustion engine with gaseous fuel, which has a device for metering injectors with gaseous fuel. The device comprises a pressure regulating unit with a shut-off valve, a pressure control valve and an overflow valve, which form a structural unit. With the shut-off valve open, the gaseous fuel is metered, wherein the gaseous fuel first enters a high-pressure accumulator or gas rail to which at least one injector is connected. By opening the overflow valve, gaseous fuel ca...

AI Technical Summary

Problems solved by technology

This pressure difference can lead to irreparable damage to the sealing element (plastic deformation, formation of cracks), so that the function of the gas pressure regulator is continuously disturbed

In the worst case, gas can leak into the area of ​​the diesel return, so that an explosive gas-diesel mixture can form in the diesel tank

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