Exhaust gas recirculation valve, thawing system of exhaust gas recirculation valve, and engine

Patent metadata

Field	Value
Publication number	US-10030618-B2
Application number	US-201515026156-A
Country	US
Kind code	B2
Filing date	Sep 11, 2015
Priority date	Sep 11, 2015
Publication date	Jul 24, 2018
Grant date	Jul 24, 2018

Abstract

An exhaust recirculation valve includes: a valve housing including an exhaust gas path; a valve element provided to the exhaust gas path and configured to open and close the exhaust gas path; and a stem connected to the valve element and movable in an axial direction, in which the valve housing includes: an inlet from which fluid is supplied from the outside; a recess configured to flow the fluid flowed from the inlet toward the stem; and a throttle in a form of an opening extending from the inlet and oriented toward the stem.

First claim

The invention claimed is:

1. An exhaust gas recirculation valve comprising:
a valve housing comprising an exhaust gas path;
a valve element provided in the exhaust gas path and configured to open and close the exhaust gas path;
a stem connected to the valve element and movable in an axial direction, and
a bush that supports the stem in a slidable manner,
wherein the valve housing comprises:
an inlet branched from a cooling water circuit of an engine and configured to supply an engine cooling water;
an outlet from which the engine cooling water is flowed;
a recess configured to flow the engine cooling water flowed from the inlet to pass near the stem to the outlet; and
a throttle opened to extend from the inlet and oriented toward the stem and configured to inject the engine cooling water into the recess to stir the engine cooling water in the recess, the throttle being integrated with the valve housing,

wherein the recess comprises:
an opening oriented in the same direction as an exhaust gas inlet;
a first recess provided near the opening, the first recess being in communication with the inlet and the outlet through the opening to define a first flow path connecting the inlet and the outlet; and
a second recess extending from the first recess toward the stem and in an opposite direction from the inlet and the outlet, the second recess being closed by the valve housing and provided at a position out of the first flow path, and

wherein the second recess is spaced apart at a predetermined distance through a thick portion of the valve housing from an inflow path of the exhaust gas path from which the exhaust gas is flowed and is positioned near the bush that supports the stem through a thin portion of the valve housing, the second recess being located closer to the stem relative to the inflow path.

2. A thawing system of an exhaust gas recirculation valve, comprising:
the exhaust gas recirculation valve according to claim 1 ;
a supply flow path configured to supply the engine cooling water to the exhaust gas recirculation valve; and
a return flow path configured to return the engine cooling water from the exhaust gas recirculation valve to a return side of the cooling water circuit of the engine.

3. The thawing system of the exhaust gas recirculation valve according to claim 2 , wherein
the cooling water circuit of the engine comprises: a first cooling water circuit comprising a pump on a side where the engine cooling water is flowed to the engine; and a second cooling water circuit configured to branch the engine cooling water via a thermostat on the side of the engine from which the engine cooling water is flowed and return the engine cooling water to the pump through a radiator,
the supply flow path is branched from the cooling water circuit of the engine at a position between the thermostat and a side of the pump from which the engine cooling water is flowed, and
the return flow path is configured to return the engine cooling water to the cooling water circuit of the engine at a position between a side of the radiator from which the engine cooling water is flowed and a side of the pump into which the engine cooling water is flowed.

4. An engine installed with the thawing system of the exhaust gas recirculation valve according to claim 2 .

5. The exhaust gas recirculation valve according to claim 1 , wherein the throttle is configured to inject the engine cooling water toward a center of the second recess.

6. The exhaust gas recirculation valve according to claim 1 , wherein the second recess is integrally formed within the valve housing.

7. The exhaust gas recirculation valve according to claim 6 , wherein the second recess is positioned between the first recess and the bush that supports the stem.

8. The exhaust gas recirculation valve according to claim 1 , wherein at least a portion of the second recess is defined by the thick portion of the valve housing and the thin portion of the valve housing, the thin and thick portions of the valve housing being integrally formed as a single piece.

9. The exhaust gas recirculation valve according to claim 1 , wherein the second recess extends downward from the first recess.

10. The exhaust gas recirculation valve according to claim 1 , wherein at least a portion of the second recess is positioned vertically below the first recess.

11. The exhaust gas recirculation valve according to claim 1 , wherein the second recess is positioned at a vertically lowermost portion of the recess.

12. The exhaust gas recirculation valve according to claim 1 , wherein the second recess is configured to hold the engine cooling water.

Assignees

• Komatsu Mfg Co Ltd

Inventors

• Miki Akihiro
• Seiyama Hideyuki
• KARASAWA Masashi

Classifications

• F02M26/72

  Housings · CPC title

• F02M26/73 Primary

  with means for heating or cooling the EGR valve · CPC title

• F02M26/69

  having two or more valve-closing members · CPC title