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

Abstract

The invention relates to a valve assembly (1) for controlling the gas pressure in a gas rail (2) of a fuel system for supplying an internal combustion engine with a gaseous fuel, in particular with natural gas, comprising a first valve (3) for connecting the gas rail (2) to a gas feed (4), a second valve (5) for connecting the gas rail (2) to a gas return (6), and a control piston (7) for actuating both valves (3, 5), wherein the control piston (7) delimits a control chamber (8), to which a hydraulic pressure medium can be applied by a pressure medium feed (9) and which can be depressurized via a pressure medium discharge (10), and further comprising a sealing element (11) which is designed as a corrugated or folding bellows and is arranged between a gas chamber (12) and a pressure mediumchamber (13) for media separation. The valve assembly is characterized by a pressure differential limiting valve (14) having a reciprocating piston (15) which, on the one hand, is acted upon by a pressure (p1) prevailing in the gas chamber (12) and which, on the other hand, is acted upon by a pressure (p2) prevailing in the pressure medium chamber (13), and which opens an additional gas return (16) when a predetermined pressure differential applied to the piston (15) is exceeded. The invention further relates to a fuel system comprising a valve assembly (1) according to the invention for controlling the gas pressure in a gas rail (2).

Description

technical field [0001] The invention relates to a valve arrangement for regulating the gas pressure in the gas rail of a fuel system for supplying an internal combustion engine with a gaseous fuel, in particular natural gas, having the features of the preamble of claim 1 . The invention also relates to a fuel system for supplying an internal 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 regulation unit with a shut-off valve, a pressure control valve and a discharge valve, which form a structural unit. With the shut-off valve open, the gaseous fuel is metered, wherein the gaseous fuel first reaches the high-pressure accumulator or the gas rail to which at least one injecto...

AI Technical Summary

Problems solved by technology

Such high pressure differences can lead to irreparable damage (plastic deformation, crack formation) of the sealing element, so that the function of the gas pressure regulator is permanently impaired

In the worst case, it can lead to gas leakage into the diesel return area, so that an explosive gas-diesel mixture can form in the diesel tank

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