JP2800022B2 - Exhaust gas purification device for internal combustion engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an exhaust gas purification apparatus for an internal combustion engine, and more particularly to a V-type internal combustion engine mounted on a front portion of a vehicle in a lateral direction with respect to the vehicle.
The present invention relates to an exhaust gas purifying apparatus for an internal combustion engine, in which a start cat is provided in an exhaust passage and a catalytic converter is provided downstream of a junction of the front and rear exhaust paths.

[Background Art] A V-type internal combustion engine is used for engines having a large total displacement, for example, having six or more cylinders, and the internal combustion engine is arranged in a V-type to shorten the overall length and secure high rigidity. .

As an exhaust gas purifying device for an internal combustion engine, Japanese Utility Model Application Laid-Open No.
Is disclosed in Japanese Unexamined Patent Application Publication No. 2000-205,878. The exhaust gas purifying apparatus for an internal combustion engine disclosed in this publication is provided with a start cat only in a front exhaust pipe connected to a front exhaust manifold, and has a double pipe structure that joins immediately upstream of a catalytic converter.

Further, there is one disclosed in Japanese Utility Model Laid-Open No. 63-98425. The exhaust gas purifying device disclosed in this publication accommodates a first and a second catalyst in a container and separately partitions the first and the second catalysts. 1. Passing through the second catalyst.

[Problems to be Solved by the Invention] By the way, in a conventional exhaust gas purifying apparatus for an internal combustion engine, as disclosed in Japanese Utility Model Laid-Open No. 63-98425,
Those that do not have a start cat or the above-mentioned
As disclosed in JP-A-130614, there are a type in which a start cat is provided only in a front exhaust pipe, and a type in which a start cat is provided in both front and rear exhaust pipes.

However, in those without a start cat, it takes time for the catalyst to rise to the activation temperature,
There is an inconvenience that the purification start is delayed and the usability is poor.

In the case where the start cat is provided only in the front exhaust pipe, it is necessary to immediately raise the activation temperature to the activation temperature in order to start the reaction of the main catalytic converter after the cold start, but the start cat is provided in the rear exhaust pipe. And the start cat is not heated effectively, it takes a long time to raise the main catalytic converter to the activation temperature, and the operation start of the catalytic converter is delayed, which is practically disadvantageous. There is a disadvantage that there is.

Furthermore, in the case where the start cats are provided in both the front and rear exhaust pipes, the start catalyst is provided in each of the front and rear exhaust pipes, so that the main catalyst is provided in comparison with the former. Although the time required to raise the converter to the activation temperature can be shortened, two expensive start cats are used, which is disadvantageous in that the cost increases and the cost is disadvantageous.

[Object of the Invention] Accordingly, an object of the present invention is to provide a catalytic converter downstream of a junction of a first exhaust pipe of one internal combustion engine and a second exhaust pipe of the other internal combustion engine in order to eliminate the above-mentioned disadvantages. An end portion of the second exhaust pipe is disposed at the junction, and a junction pipe having a double tubular outer pipe disposed outside the end portion is provided, and the second exhaust pipe in the junction pipe is provided. A start cat is provided at an end and the first exhaust pipe is connected to an external pipe disposed in the double pipe, and after the exhaust gas from the first exhaust pipe passes through the outer periphery of the start cat, the second exhaust pipe is connected to the second exhaust pipe.
It merges with the exhaust gas from the exhaust pipe, effectively heats the start cat after the cold start, and can quickly raise the catalytic converter to the activation temperature, which is practically advantageous and one expensive start cat. An object of the present invention is to realize an exhaust gas purifying apparatus for an internal combustion engine, which does not increase cost and is economically advantageous due to its use.

Means for Solving the Problems In order to achieve this object, the present invention relates to a V-type internal combustion engine exhaust purification device which is mounted on a front portion of a vehicle in a lateral direction with respect to the vehicle. A catalytic converter is provided downstream of a junction between the first exhaust pipe and a second exhaust pipe of the other internal combustion engine, an end of the second exhaust pipe is disposed at the junction, and an outside of the end is provided. A confluence pipe in which an external pipe is disposed in a double pipe, a start cat is provided in an end of the second exhaust pipe in the confluence pipe, and the first exhaust pipe is connected to an external pipe disposed in the double pipe. The exhaust gas from the first exhaust pipe is connected to the exhaust gas from the second exhaust pipe after passing through the outer periphery of the start cat.

[Operation] With the configuration described above, after the internal combustion engine is started in a cold state, the start cat provided at the end of the second exhaust pipe is effectively heated by the exhaust gas from the other exhaust pipes, and this start cat The catalytic converter is quickly raised to the activation temperature, which is practically advantageous. In addition, only one expensive start cat is used, so that the cost does not increase and the economical advantage is obtained.

Embodiment An embodiment of the present invention will be described below in detail with reference to the drawings.

1 to 3 show an embodiment of the present invention. In FIG. 1, reference numeral 2 denotes a V-type internal combustion engine.

As shown in FIG. 1, the V-type internal combustion engine 2 is mounted laterally with respect to the vehicle in an engine room (not shown) at the front of the vehicle (not shown), and is disposed in a V-shape. For example, it comprises a front first internal combustion engine 4 and the other, for example, a rear second internal combustion engine 6.

The upstream end of the first exhaust pipe 8 is connected to the front first internal combustion engine 4, and the second end of the first exhaust pipe 8 is connected to the rear second internal combustion engine 6.
The upstream end of the exhaust pipe 10 is connected.

A first exhaust passage 12 is formed in a first exhaust pipe 8 of a front first internal combustion engine 4 of the V-type internal combustion engine 2, and a rear second internal combustion engine 6 is formed.
A second exhaust passage 14 is formed in the second exhaust pipe 10.

A catalytic converter 16, which is a main catalyst, is provided downstream of the junction of the first exhaust passage 12 and the second exhaust passage 14.

An end of the second exhaust pipe 10 is provided at the junction of the first exhaust passage 12 and the second exhaust passage 14, and an outer pipe 22 is provided outside the end in a double tubular shape. The start pipe 20 is provided at the end of the second exhaust pipe 10 in the merge pipe 18 and the first exhaust pipe 8 is connected to the external pipe 22 disposed in the double pipe. Then, the exhaust gas from the first exhaust pipe 8 merges with the exhaust gas from the second exhaust pipe 10 after passing through the outer periphery of the start cat 20.

More specifically, as shown in FIGS. 1 and 2, the merging pipe 18 includes the second exhaust pipe 10 and an outer pipe 22.
The first exhaust pipe 8 is communicated with an upstream side portion of the first exhaust pipe 8.

At this time, as shown in FIG.
A is formed in a double tubular shape by a second exhaust pipe 10, and exhaust gas passing through the first exhaust passage 12 in the first exhaust pipe 8 flows on the downstream side 18B, that is, the second exhaust pipe. After passing through the outer circumference of the start cat 20 provided at the end of the exhaust pipe 10, the exhaust gas passes through the second exhaust passage 14 in the second exhaust pipe 10 and joins with the exhaust gas.

As shown in FIG. 3, the start cat 20 is made of ceramic or metal formed by spirally winding a flat plate 24 and a corrugated plate 26 made of a heat-resistant steel material having a thickness equal to or less than a predetermined thickness. It is formed by supporting a catalyst substance on a carrier.

 Next, the operation will be described.

After the cold start of the V-type internal combustion engine 2, the exhaust gas of the rear second internal combustion engine 6 warms the start cat 20 in the middle of the second exhaust passage 14, and the outer peripheral portion of the second exhaust pipe 10 (1) The start cat 20 is heated by the exhaust gas from the internal combustion engine 4 and rises to the activation temperature.

Then, the exhaust gas in the merging pipe 18 is heated by the reaction heat of the start cat 20 which has reached the activation temperature, and the first,
After the second exhaust passages 12, 14 merge, the catalytic converter
Heat 16

At this time, the start cat 20 and the catalytic converter
The second exhaust passage 14 between the V-type internal combustion engine 2 and the V-type internal combustion engine 2 has a short passage length.

Then, the catalytic converter 16 is quickly heated,
When the catalytic converter 16 reaches the activation temperature, heat of combustion reaction is generated from the central portion to heat the catalytic converter 16 and quickly raise the entire catalytic converter 16 to the activation temperature.

Accordingly, the start cat 20 in the middle of the second exhaust pipe 14 can be effectively heated and easily and quickly raised to the activation temperature, and the exhaust gas can be further heated by the reaction heat of the start cat 20, Catalytic converter
The catalyst converter 16 can be easily heated to the activation temperature to quickly heat the entire catalytic converter 16 to the activation temperature, and the time from the start of the cooler to the start of the reaction can be shortened, which is practically advantageous.

Further, since the start cat 20 is provided only in the middle of the second exhaust passage 14, the start cat 20 is more expensive than the conventional one in which the start cat 20 is provided in each of the first and second exhaust passages 12, 14. The number can be reduced,
The cost can be reduced, which is economically advantageous.

Further, a second exhaust passage is provided at an upstream portion of the merging pipe 18.
By covering the outer circumference of the first exhaust passage 12 with the first exhaust passage 12, it is possible to prevent the heat of the catalyst of the start cat 20 from being dissipated to the outside and to exert a heat retaining function, which is practically advantageous.

Note that the present invention is not limited to the above-described embodiment, and various application modifications are possible.

For example, in the embodiment of the present invention, the merge pipe is formed by the second exhaust pipe of the rear second internal combustion engine and the external pipe, and the first exhaust pipe is communicated with the upstream portion of the external pipe. However, it is also possible to adopt a configuration in which the merging pipe is formed by the first exhaust pipe of the front first internal combustion engine and the external pipe, and the second exhaust pipe communicates with the upstream part of the external pipe.

Further, in the embodiment of the present invention, the start cat as the sub-catalyst is disposed in the second exhaust pipe on the upstream side of the junction pipe, but between the inner circumference of the outer pipe constituting the junction pipe and the outer circumference of the second exhaust pipe. A start cat can be provided.

[Effects of the Invention] As described in detail above, according to the present invention, a catalytic converter is provided downstream of the junction of the first exhaust pipe of one internal combustion engine and the second exhaust pipe of the other internal combustion engine, An end of the second exhaust pipe is disposed at the junction, and a junction pipe having an outer pipe arranged in a double tube outside the end is provided, and an end of the second exhaust pipe in the junction is provided at an end of the second exhaust pipe. A start cat is provided and the first exhaust pipe is connected to the outer pipe arranged in the double pipe, and after the exhaust gas from the first exhaust pipe passes through the outer periphery of the start cat, the first exhaust pipe is connected to the outer pipe. Since the exhaust gas is merged with the exhaust gas, the start cat provided at the end of the second exhaust pipe can be effectively heated to easily and quickly rise to the activation temperature. It can be further heated, and the catalyst converter The catalyst can be easily heated to the activation temperature to quickly heat the entire catalytic converter to the activation temperature, and the time from the start of the cooler to the start of the reaction can be shortened, which is practically advantageous. Then, the exhaust gas from the first exhaust pipe passes through the outer periphery of the start cat provided at the end of the second exhaust pipe, so that the exhaust gas effectively heats the catalyst and heats the start cat to the outside. Is prevented from dispersing, and a heat retaining function can be exhibited. In addition, since the start cat is provided only at the end of the second exhaust pipe, the number of expensive start cats can be reduced as compared with the conventional one in which the start cat is provided on both exhaust pipes, and the cost is reduced. Can be inexpensive, which is economically advantageous.

[Brief description of the drawings]

1 to 3 show an embodiment of the present invention, FIG. 1 is a schematic side view of a V-type internal combustion engine, FIG. 2 is an enlarged sectional view of a main part of a merging pipe, and FIG. It is an expanded sectional view of the merging pipe by the III line. In the figure, reference numeral 2 denotes a V-type internal combustion engine, 4 denotes a front first internal combustion engine, 6 denotes a rear second internal combustion engine, 8 denotes a first exhaust pipe, and 10 denotes a second exhaust pipe.
Exhaust pipe, 12 is a first exhaust path, 14 is a second exhaust path, 16 is a catalytic converter, 18 is a merge pipe, 20 is a start cat, 22
Is an outer tube.

Claims (1)

(57) [Claims] An exhaust purification system for a V-type internal combustion engine mounted laterally with respect to a vehicle at a front portion of the vehicle, wherein a first exhaust pipe of one internal combustion engine and a second exhaust pipe of the other internal combustion engine are connected. A catalytic converter is provided downstream of the merging site, and an end of the second exhaust pipe is arranged at the merging site, and a merging tube is provided outside the end and a double tube is provided with an outer tube, A start cat is provided at the end of the second exhaust pipe in the merging pipe, and the first exhaust pipe is connected to an external pipe arranged in the double pipe, and exhaust gas from the first exhaust pipe is supplied to the start cat. An exhaust purification device for an internal combustion engine, wherein the exhaust gas is merged with the exhaust gas from the second exhaust pipe after passing through an outer periphery.