Exhaust gas recirculation system

Abstract

To prevent inflow of condensed water to an exhaust gas recirculation (EGR) valve, an exhaust gas recirculation system includes a first gas passage, an exhaust gas recirculation valve connected to the first gas passage and selectively opening/closing the first gas passage, an exhaust gas passage disposed in the exhaust gas recirculation valve, and a second gas passage connecting the exhaust gas passage to an air-fuel mixture passage. The exhaust gas passage is tilted at a predetermined angle with respect to the second gas passage. The predetermined angle may be greater than about 10°, and in some embodiments the predetermined angle is about 15°.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an EGR system according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An exemplary embodiment of the present invention will hereinafter be described in detail with reference to the accompanying drawing.

According to an exemplary embodiment of the present invention, a first gas passage 207 transmits some of the exhaust gas from an exhaust manifold 209. An EGR valve 205 is connected to the first gas passage 207 and selectively opens/closes the first gas passage 207.

A second gas passage 203 is mounted to a cylinder head 201 and connects the EGR valve 205 to an air-fuel mixture passage 213 such that the exhaust gas inflows from the EGR valve 205 to a combustion chamber 215, and the exhaust gas passage 204 of the EGR valve is bent at a predetermined angle with respect to the second gas passage 203 such that inflow of condensed water from the exhaust gas is prevented.

The exhaust gas flows from the exhaust gas passage or exhaust manifold 209 to the EGR valve 205 through the first gas passage 207. The EGR valve 205 is opened/closed by an engine control unit (not shown), which may include a processor, memory, and associated hardware, software, and/or firmware as may be selected and programmed by a person of ordinary skill in the art based on the teachings of the present invention.

The exhaust gas sequentially passes through the exhaust gas passage 204 of the EGR valve 205 and the second exhaust gas passage 203. The exhaust gas is mixed with the air-fuel mixture in the air-fuel mixture passage 213 and flows to the combustion chamber 215.

In some embodiments, the exhaust gas passage 204 of the EGR valve 205 is bent at over 10° with respect to the second exhaust gas passage 203, and in some embodiments, it is bent at 15°. However, the predetermined angle may be chosen based on tilt angle when the engine is mounted to an engine compartment, by exhaust amount of the vehicle, or by the size of the engine. Due to this bend, condensed water cannot inflow to the EGR valve 205.

If the engine stops at low temperatures, such as in winter, the condensed water may be frozen in the second exhaust gas passage 203. However, in this case, when the engine starts, the frozen water evaporates by the inflow of the exhaust gas, which is generally over 500° C.

Therefore, according to an exemplary embodiment of the present invention, the inflow of condensed water to the EGR valve 205 is prevented, freezing of the condensed water in the EGR valve 205 is prevented, and ice in the second exhaust gas passage 203 is prevented from inflowing to the combustion chamber 215.

While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. An exhaust gas recirculation system, comprising: a first gas passage;an exhaust gas recirculation valve connected to the first gas passage and selectively opening/closing the first gas passage;an exhaust gas passage disposed in the exhaust gas recirculation valve; anda second gas passage connecting the exhaust gas passage to an air-fuel mixture passage;wherein the exhaust gas passage is tilted at a predetermined angle with respect to the second gas passage.

2. The system of claim 1, wherein the predetermined angle is greater than about 10°.

3. The system of claim 2, wherein the predetermined angle is about 15°.