Exhaust gas purification device for internal combustion engines

Abstract

The invention provides an exhaust gas purification device for an internal combustion engine, the device has better cooling efficiency than before, and the low-cost structure can realize compact and excellent packaging and arrangement. The exhaust gas purification device (1) comprises an EGR pipe (11) which takes EGR gas flow back to an intake channel, an EGR cooler (12) which is arranged on the EGR pipe and is used for cooling EGR gas through performing heat exchange with cooling water that is used for cooling an engine (2) and is introduced from an internal combustion engine cooling circuit (3), and an EGR cooling circuit (13) which is used for connecting an introduction port (123) and an exhaust port (124) of cooling water formed on the EGR cooler with the internal combustion engine cooling circuit, at least a part of the EGR cooling circuit passes through the EGR pipe on the downstream side in a backflow direction of the EGR cooler and the connection portion (10) of the EGR cooler, extends along the EGR pipe and is integrated with the EGR pipe through a separation wall (110) with thermal conductivity, and a sealing pad (100) for sealing the cooling water and the EGR gas is arranged on the connection portion.

Description

technical field [0001] The invention relates to an exhaust gas purification device of an internal combustion engine. More specifically, it relates to an exhaust gas purification device for an internal combustion engine including an EGR passage and an EGR cooler. Background technique [0002] Conventionally, there is known an exhaust gas purification device for an internal combustion engine including an EGR passage for returning a part of exhaust gas to the intake passage as EGR gas, and an EGR cooler for cooling the EGR gas. The EGR cooler is installed in the middle of the EGR passage, and cools the EGR gas by exchanging heat with cooling water introduced from an engine cooling circuit for cooling the internal combustion engine. [0003] In the above-mentioned EGR cooler, an inlet and an outlet for cooling water are formed, and an EGR cooling circuit that connects these inlets and outlets to the cooling circuit of the internal combustion engine is provided. This EGR coolin...

AI Technical Summary

Problems solved by technology

Therefore, it is necessary to form a double-layer pipe part with a high-temperature heat-resistant member such as a steel pipe or cast iron, which is more difficult to form than aluminum castings. Therefore, it is actually difficult to achieve compactness, and there are difficulties in packaging and layout. cost increase

In addition, as a sealing member used in the connection between the double pipe part and the heat exchange core, O-rings other than rubber, laminated gaskets, brazing and other sealing members with high temperature and heat resistance are required. Based on this, manufacturing costs will rise

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