JP2005054662A - Exhaust device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-sized/light-weight exhaust device for a vehicle enabling a measure against trouble due to heating to be easily taken. <P>SOLUTION: This exhaust device for the vehicle comprises an exhaust system feeding exhaust emission from an internal combustion engine 1 mounted on the vehicle to a silencer 14 through a catalytic converter 8 and discharging the exhaust emission from the silencer 14. A heat exchanger 10 is disposed between the catalytic converter 8 and the silencer 14, and the heat exchanger 10 cools the exhaust emission by a cooling fluid. The cooling fluid is supplied from a radiator 2 supplying the cooling fluid to the internal combustion engine 1. Also, the silencer 14 is disposed on the bumper of the vehicle. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vehicle exhaust device that purifies exhaust gas discharged from an internal combustion engine mounted on a vehicle by a catalytic converter, sends the catalyst converter to a silencer, and discharges the noise from the silencer, as disclosed in Patent Document 1.

Conventionally, an exhaust system of an internal combustion engine mounted on a vehicle collects exhaust gas from the internal combustion engine by an exhaust manifold, and then sends the exhaust gas to a catalytic converter provided with a three-way catalyst to purify the exhaust gas. This three-way catalyst is usually activated at about 300 ° C. or higher. The exhaust gas from the catalytic converter is sent to a silencer to silence the exhaust gas, and then exhausted. Some silencers include a secondary silencer and a main silencer.
JP 2002-008999 A

  However, in such a conventional system, since the exhaust gas is at a high temperature, it is necessary to consider heat resistance, and a heat-resistant material must be used for the exhaust system structure, and the exhaust system structure is heavy. Because of the high-temperature exhaust, there was a problem that countermeasures against heat damage had to be considered.

  An object of the present invention is to provide a small and lightweight vehicle exhaust device that is easy to take measures against heat damage.

In order to achieve this problem, the present invention has taken the following measures in order to solve the problem. That is,
In a vehicle exhaust system for sending exhaust gas from an internal combustion engine mounted on a vehicle to a silencer via a catalytic converter and discharging the silencer,
A heat exchanger is disposed between the catalytic converter and the silencer, and the heat exchanger cools the exhaust with a coolant, which is a vehicle exhaust device.

  The coolant may be supplied from a radiator that supplies coolant to the internal combustion engine. Further, the silencer may be disposed in a vehicle bumper.

  As described above, the vehicle exhaust device of the present invention has an effect that it is easy to take measures against heat damage and can be reduced in size and weight.

The best mode for carrying out the present invention will be described below in detail with reference to the drawings.
As shown in FIG. 1, reference numeral 1 denotes an internal combustion engine, which is mounted on a vehicle (not shown). The internal combustion engine 1 is a liquid cooling type, and the cooling liquid cooled by the radiator 2 is supplied to the internal combustion engine 1.

  Exhaust gas from the internal combustion engine 1 is collected by the exhaust manifold 4, led to the exhaust pipe 6, and led to the catalytic converter 8 from the exhaust pipe 6. The exhaust gas is further supplied from the catalytic converter 8 to the heat exchanger 10. The heat exchanger 10 performs heat exchange between the supplied exhaust gas and the coolant, and cools and exhausts the exhaust gas.

  In the present embodiment, the coolant is connected so as to be supplied from the radiator 2, and is configured to cool the exhaust gas passing through a narrow tube (not shown) in the heat exchanger 10 from the outside of the narrow tube with the coolant. ing. The high-temperature coolant is returned to the radiator 2, cooled by the radiator 2, and then circulated and supplied to the heat exchanger 10 again. The radiator 2 is also used for cooling the internal combustion engine 1. However, the radiator 2 is not limited to this, and a dedicated radiator for the heat exchanger 10 may be provided.

  The exhaust gas that has passed through the heat exchanger 10 is guided to the silencer 14 through the exhaust pipe 12, passes through the silencer 14, and is discharged from the tail pipe 16 into the atmosphere. The silencer 14 may be disposed on the bottom surface of the vehicle by reducing the size of the conventional silencer, or may be disposed in the bumper 18 at the rear of the vehicle as shown in FIGS. 2 and 3 as in the present embodiment. You can also

  The silencer 14 includes a resonance chamber 20, an expansion chamber 22, and a final chamber 24 formed in the bumper 18. An exhaust pipe 12 is opened in the expansion chamber 22, and the resonance chamber 20 and the expansion chamber 22 are connected by a communication pipe 26. The exhaust gas that has passed through the expansion chamber 22 passes through the final chamber 24 and is discharged from the tail pipe 16.

Next, the operation of the above-described vehicle exhaust device of the present embodiment will be described.
In accordance with the operation of the internal combustion engine 1, the coolant is cooled through the radiator 2 and supplied to the internal combustion engine 1. The internal combustion engine 1 is cooled by the coolant, and the high-temperature coolant is returned to the radiator 2 to be cooled, and the internal combustion engine 1 is cooled while circulating between the internal combustion engine 1 and the radiator 2.

  Exhaust gas discharged from the internal combustion engine 1 is introduced into the catalytic converter 8 through the exhaust pipe 6 and the exhaust gas is purified. The exhaust gas that has passed through the catalytic converter 8 is introduced into the heat exchanger 10, and heat exchange is performed between the exhaust gas and the coolant, thereby cooling the exhaust gas. The coolant whose temperature has risen is returned from the heat exchanger 10 to the radiator 2. The coolant cooled by the radiator 2 is supplied again to the heat exchanger 10 to cool the exhaust.

  For example, when an exhaust gas having a temperature of about 800 ° C. is introduced into the heat exchanger 10 and cooled by the heat exchanger 10, the exhaust gas has a temperature of about 150 ° C. and is discharged to the silencer 14. When the exhaust is cooled around 650 ° C., the pressure of the exhaust decreases accordingly. Since the heat exchanger 10 is provided on the downstream side of the catalytic converter 8, high-temperature exhaust gas is introduced into the catalytic converter 8 and does not hinder the activity of the catalyst.

  Exhaust gas whose pressure has been reduced due to cooling is introduced into the silencer 14 and discharged from the silencer 14 and the tail pipe 16 into the atmosphere. As the exhaust gas passes through the silencer 14, noise can be reduced. When introduced into the silencer 14, the exhaust is cooled and the exhaust pressure is reduced, so that the silencing effect of the silencer 14 is improved.

  For example, in FIG. 4, the sound pressure level when exhaust gas that does not pass through the heat exchanger 10 is introduced into the silencer 14 is indicated by a two-dot chain line, and exhaust gas that has passed through the heat exchanger 10 is introduced into the same silencer 14. The sound pressure level is indicated by a solid line. Thus, when the heat exchanger 10 is passed, the sound pressure level can be greatly reduced.

  Therefore, even when the heat exchanger 10 is downsized, it is possible to maintain a level equivalent to the silencing performance when the heat exchanger 10 is not provided. Therefore, the silencer 14 can be downsized and disposed in the bumper 18. Further, since the exhaust gas introduced into the silencer 14 is cooled by the heat exchanger 10, the silencer 14 can be formed of a light material having low heat resistance such as aluminum or resin.

  As shown in FIG. 3, the exhaust introduced into the silencer 14 via the exhaust pipe 12 is expanded by the expansion chamber 22 and is silenced by the resonance effect of the resonance chamber 20. Then, it is discharged into the atmosphere through the final chamber 24 and the tail pipe 16. Thus, even with the small silencer 14 disposed in the bumper 18, sufficient silencing performance can be obtained.

  Therefore, since the size of the silencer 14 can be reduced, the weight can be reduced. Moreover, since the silencer 14 can be disposed in the bumper 18, the degree of freedom of the space under the vehicle floor is improved. Further, since the exhaust gas introduced into the silencer 14 is cooled by the heat exchanger 10, no measures against heat damage are required even if it is disposed in the bumper 18, and even if it is a resin bumper 18. it can.

  The present invention is not limited to such embodiments as described above, and can be implemented in various modes without departing from the gist of the present invention.

1 is a schematic configuration diagram of a vehicle exhaust device according to an embodiment of the present invention. It is a layout view of the muffler disposed in the bumper of the present embodiment in the vehicle front-rear direction. It is a layout of the silencer arranged in the bumper of this embodiment in the vehicle width direction. It is a graph which shows the silencing effect by having provided the heat exchanger of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 2 ... Radiator 4 ... Exhaust manifold 6,12 ... Exhaust pipe 8 ... Catalytic converter 10 ... Heat exchanger 14 ... Silencer 16 ... Tail pipe 18 ... Bumper 20 ... Resonance chamber 22 ... Expansion chamber 24 ... Final chamber

Claims (3)

In a vehicle exhaust system for sending exhaust gas from an internal combustion engine mounted on a vehicle to a silencer via a catalytic converter and discharging the silencer,
An exhaust system for a vehicle, wherein a heat exchanger is disposed between the catalytic converter and the silencer, and the heat exchanger cools the exhaust with a coolant. The exhaust system for a vehicle according to claim 1, wherein the coolant is supplied from a radiator that supplies the coolant to the internal combustion engine. The vehicle exhaust system according to claim 1 or 2, wherein the silencer is disposed in a bumper of the vehicle.

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