JP2004092442A - Egr device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance assembly workability by reducing the number of components of an EGR device, and to eliminate fear such as gas leakage and the like. <P>SOLUTION: An EGR cooler 10 provided with a heat exchanging function, an upstream pipe 13 for connecting an exhaust inlet 11 of the EGR cooler to an exhaust manifold, and a downstream pipe 14 for connecting an exhaust outlet 12 of the EGR cooler 10 to an intake manifold are previously integrally formed, thereby eliminating necessity of existing of a fastening part by a flange in the middle of the EGR device. Accordingly, the number of components is reduced, the assembly workability is considerably improved, and durability of the EGR device is enhanced. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an EGR device used as an engine exhaust gas technology, and more particularly to an EGR device provided with an EGR cooler that cools EGR gas recirculated to an intake system to reduce a heat load on the engine.
[0002]
[Prior art]
In order to reduce the thermal load on the engine by cooling the EGR gas recirculated to the intake system, the use of various EGR coolers has been conventionally studied and put into practical use.
[0003]
In such a conventional EGR device, as shown in FIG. 2, in addition to an EGR cooler 1 having a heat exchange function, an upstream pipe 3 connecting an exhaust inlet of the EGR cooler 1 to an exhaust manifold 2; A downstream pipe 5 that connects the exhaust outlet of the EGR cooler 1 to the intake manifold 4 is prepared, and flanges 1a, 3a, and 5a are provided at ends of the EGR cooler 1 and the upstream and downstream pipes 3, 5, respectively. The gasket 6 is sandwiched between the flanges 1a, 3a, and 5a, and is tightened and fixed with a bolt (not shown) to constitute an EGR device.
[0004]
However, in the case where the EGR device is divided into three parts, that is, the EGR cooler 1 and the pipes 3 and 5 on the upstream and downstream sides and these are connected by the flanges 1a, 3a and 5a, the number of parts increases and the engine is simultaneously mounted on the engine. However, there is a possibility that gas leakage may occur if the sealability of the fastening part is deteriorated due to aging, and some measures have been demanded.
[0005]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to reduce the number of parts of an EGR device to improve assembling workability and to eliminate concerns such as gas leakage.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides an EGR cooler having a heat exchange function, an upstream pipe connecting an exhaust inlet of the EGR cooler to an exhaust manifold, and connecting an exhaust outlet of the EGR cooler to an intake manifold. The feature is that the downstream pipe is integrated.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an external perspective view showing an embodiment of the EGR device according to the present invention.
[0008]
In FIG. 1, an EGR cooler 10 having a heat exchange function is composed of a cylindrical shell and a number of heat exchange tubes and the like housed inside the shell, and EGR gas and heat flowing outside the heat exchange tubes. The EGR gas returned to the intake system is cooled by exchanging heat of the engine cooling water flowing inside the exchange tube through the heat exchange tube. The heat exchange (cooling of the EGR gas) model and specific configuration in the EGR cooler are not limited to those of the embodiment.
[0009]
At the exhaust inlet 11 and exhaust outlet 12 of the EGR cooler 10, an upstream pipe 13 leading to an exhaust manifold (not shown) and a downstream pipe 14 leading to an intake manifold (not shown) are welded and fixed at joining portions 15 and 16, respectively. , The EGR cooler 10 and the upstream pipe 13 and the downstream pipe 14 are integrated.
[0010]
Reference numeral 17 denotes a joining flange provided at the tip of the upstream pipe 13 corresponding to a joining flange provided at an exhaust manifold (not shown), and reference numeral 18 denotes a joining flange provided at a tip of the downstream pipe 14 corresponding to a joining flange provided at an intake manifold (not shown). By providing a flow control valve or the like (not shown) at an appropriate position in an EGR passage from the exhaust manifold to the intake manifold, the flow rate of the EGR gas is optimally controlled according to the operating state of the engine.
[0011]
That is, in the present embodiment, since the EGR cooler 10 and the pipes 13 and 14 on the upstream and downstream sides are integrated in advance, there is no need to provide a fastening portion by a flange as in the related art. Therefore, the number of parts and the weight of the EGR device can be reduced, and at the same time, the assembling workability can be greatly improved. In addition, since the fastening portion by the flange does not exist in the middle of the EGR device, there is no need to worry about deterioration of the sealing property due to aging, and the durability of the EGR device is increased.
[0012]
【The invention's effect】
As is apparent from the above description, the present invention provides an EGR cooler having a heat exchange function, an upstream pipe connecting an exhaust inlet of the EGR cooler to an exhaust manifold, and connecting an exhaust outlet of the EGR cooler to an intake manifold. In order to eliminate the need to provide a fastening part with a flange in the middle of the EGR device by integrating the downstream pipe in advance, the number of parts and weight are reduced, and assembly workability is greatly improved. And the durability of the EGR device is increased.
[Brief description of the drawings]
FIG. 1 is an external perspective view showing an embodiment of an EGR device according to the present invention.
FIG. 2 is an external perspective view showing a conventional example of an EGR device.
[Explanation of symbols]
Reference Signs List 10 EGR cooler 11 Exhaust inlet 12 Exhaust outlet 13 Upstream pipe 14 Downstream pipes 15, 16 Joining (welding) portions 17, 18 Joining flange

Claims (1)

An EGR cooler having a heat exchange function, an upstream pipe connecting an exhaust inlet of the EGR cooler to an exhaust manifold, and a downstream pipe connecting an exhaust outlet of the EGR cooler to an intake manifold. An EGR device wherein the downstream pipes are respectively connected to and integrated with an EGR cooler.

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