Exhaust gas recirculation valves for internal combustion engines

Abstract

An exhaust gas recirculation valve for an internal combustion engine is known, comprising a housing (2) with an exhaust gas inlet (4) and an exhaust gas outlet (6), a valve closing body (10), a valve stem (12), an exhaust gas inlet (4) and Valve seat (8), guide sleeve (14) and sealing ring (18) between the exhaust gas outlet (6), where the valve closing body (10) is fixed on the valve stem (12) and the valve stem (12) can be Actuator movement, wherein the valve closing body (10) can be lowered onto the valve seat (8) by moving the valve stem (12) and the valve closing body (10) can be raised from the valve seat by the opposite movement , the valve stem ( 12 ) is guided in the housing ( 2 ) via a guide sleeve ( 14 ), a sealing ring ( 18 ) on the end of the guide sleeve ( 12 ) opposite the valve closing body ( 10 ). However, sticking of the valve or loss of seal tightness is often a problem. The invention therefore proposes to form a circumferential gap ( 32 ) between the valve stem ( 12 ) and the guide sleeve ( 14 ) in the first section ( 30 ) of the guide sleeve ( 14 ) which is directed towards the sealing ring ( 18 ) ). The mechanical load on the sealing ring ( 18 ) is thereby reduced and the guide section is shortened.

Description

Technical field [0001] The invention relates to an exhaust gas recirculation valve for an internal combustion engine, comprising a housing with an exhaust gas inlet and an exhaust gas outlet, a valve closing body, a valve stem, a valve seat between the exhaust gas inlet and the exhaust gas outlet, a guide sleeve and a sealing ring, The valve closing body is fixed on the valve stem and the valve stem can be moved by the actuator, wherein the valve closing body can be lowered onto the valve seat by moving the valve stem and the valve closing body can be raised from the valve seat by opposite movement As a result, the valve stem is guided in the housing via a guide sleeve, and the sealing ring is located on the end of the guide sleeve opposite to the valve closing body. Background technique [0002] Exhaust gas recirculation valves for adjusting the amount of recirculated exhaust gas to the corresponding operating state of the internal combustion engine so as to reduce the environme...

AI Technical Summary

Problems solved by technology

However, such a design is a rather complex structure, since several additional parts must be used to seal the valve body

In particular, the provision of a sealing membrane requires additional assembly labor and the housing with ribs results in higher production costs than housing without ribs

In addition, deposits accumulate in the area between the guide sleeve and the valve stem, which leads to sticking of the valve

[0006] Accordingly, a defect in the known examples is that dust particles entering between the guide sleeve and the valve stem lead to malfunctioning of the valve through the formation of ridges or scratches in the valve stem or through the deposits themselves

This can also affect the protection of the actuator from dust particles, leading to failure of the electronic components

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