JPH11336536A - Internal combustion engine exhaust device and catalyst converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust device for internal combustion engine together with a catalyst converter for use in it, wherein the time till the catalyst converter coming in function is shortened and the loads applied to the component parts of the exhaust device are reduced. SOLUTION: A ball joint mechanism 31 includes an upstream flange 32 fixed to the downstream end of an exhaust manifold 3, a downstream flange 33, and a bolt 35 to connect the two flanges 32 and 33 together in such a way as rotatable freely. The downstream flange 33 is furnished with a spherical portion 33a where the inside diameter reduces as tracing the spherical form. A gasket 34 is interposed between this spherical portion 33a and the exhaust manifold 3. A start catalyst 4 is equipped with an upstream guide member 4a, catalyst carrier housing member 4b, and downstream guide member. The ball joint mechanism 31 is connected with the start catalyst 4 by fixing the downstream flange 33 directly to the upstream end of the upstream guide member 4a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust system for an internal combustion engine having a ball joint mechanism for absorbing rolling vibration of the internal combustion engine, a catalytic converter for purifying harmful gas in combustion gas, and a catalyst provided in the exhaust system. It concerns a converter.

[0002]

2. Description of the Related Art As an exhaust device for an internal combustion engine of this kind,
Conventionally, for example, a structure shown in FIG. 5 is known. As shown in FIG. 5, two exhaust pipes 51 and 52 are disposed downstream of the combustion gas discharged from the engine. These exhaust pipes 51, 52 are connected to a ball joint mechanism 53. The ball joint mechanism 53 serves to rotationally absorb the rolling vibration of the engine and suppress the transmission of the rolling vibration to the downstream side. Inside the ball joint mechanism 53, the exhaust pipes 51, 5
2 and the exhaust pipes 54 and 55 communicate with each other. These exhaust pipes 54, 55 are connected to start catalysts 56, 57, respectively. The start catalysts 56 and 57 are for quickly purifying harmful gases in the combustion gas discharged from the engine at the time of a cold immediately after the start of the engine, and have a monolith for purifying the inside thereof. Contains a catalyst carrier. The start catalysts 56 and 57 are connected to the two branch pipes 58a and 58b of the collecting pipe 58, respectively. The collecting pipe 58 is connected to the main converter 59 at a collecting section 58c where these branch pipes 58a and 58b merge into one. The main converter 59 is for purifying most of the harmful gas in the combustion gas discharged from the engine when the engine is warm.

[0003] The combustion gas discharged from the internal combustion engine passes through the start catalysts 56 and 57 and the main converter 59 to purify the harmful gas, and further passes through a predetermined downstream passage to be discharged to the outside. Is done.

[0004]

In such an exhaust system, the ball joint mechanism 53 and the start catalysts 56 and 57 are connected via exhaust pipes 54 and 55, respectively. The start catalysts 56 and 57 are provided at positions farther from the internal combustion engine.

[0005] The start catalysts 56 and 57 are:
The start catalysts 56 and 57 function by being heated to a predetermined temperature or more, and are heated by the combustion gas discharged from the engine. Therefore,
When the start catalysts 56 and 57 are provided at positions far from the engine by the exhaust pipes 54 and 55 as described above, the start catalysts 56 and 57 are provided.
Becomes longer than the predetermined temperature, that is, the time until the start catalysts 54 and 55 function.

The start catalysts 56, 5
Reference numeral 7 is a heavy object due to its structure. Therefore, when the start catalysts 56 and 57 are provided at positions far from the engine by the exhaust pipes 54 and 55 as described above, each component of the exhaust system is provided. An excessive load is applied to the product.

The present invention has been made in view of such circumstances, and an object of the present invention is to shorten the time required for a catalytic converter to function and to reduce the load applied to each component of an exhaust system. It is an object of the present invention to provide an exhaust system for an internal combustion engine and a catalytic converter provided in the exhaust system.

[0008]

In order to achieve the above object, an invention according to claim 1 includes a catalytic converter that accommodates a monolithic catalyst carrier therein and has guide members on upstream and downstream sides, respectively. A ball joint mechanism for rotatably connecting the catalytic converter to an exhaust pipe of the internal combustion engine, wherein a movable end of the ball joint mechanism is directly attached to the upstream guide member of the catalytic converter. It is assumed that.

According to this structure, the movable end of the ball joint mechanism and the upstream guide member of the catalytic converter are directly attached to each other, so that the catalytic converter can exhaust the internal combustion engine without passing through an extra exhaust pipe. It is pivotally connected to the tube. Therefore, the catalytic converter is provided at a position closer to the internal combustion engine. As a result, the catalytic converter is quickly heated to the above-mentioned predetermined temperature by the combustion gas from the engine. That is, the time until the catalytic converter functions is shortened.

Further, since the catalytic converter is provided at a position closer to the internal combustion engine, the load applied to each component of the exhaust system by the catalytic converter is also reduced. According to a second aspect of the present invention, in the exhaust device for an internal combustion engine according to the first aspect, a fixed partition of the exhaust pipe and the ball joint mechanism is internally divided into two parts by a first partition. The partition wall of the first partition is provided at its tip with a disk portion protruding in an arc shape corresponding to the path of the movable end of the ball joint mechanism, and the upstream guide member of the catalytic converter is provided with the disk portion of the first partition wall. The gist of the present invention is that the catalytic converter is provided with a second partition having a cutout portion cut out in an arc shape corresponding to the shape and dividing the inside of the catalytic converter into two.

In order to reduce the influence of the combustion gases from the respective cylinders of the multi-cylinder internal combustion engine interfering with each other, these combustion gases are combined into cylinders having a small influence of the mutual interference.
In the case of separation into two groups, the inside of the fixed end of the exhaust pipe and the ball joint mechanism is divided into two by the first partition, and the divided combustion gas flows into each group. At this time, the inside of the catalytic converter rotatably connected to the exhaust pipe is also divided into two by the second partition, which divides the inside of the upstream guide member into two,
The combustion gas divided into two as described above is supplied to each of them. According to the above configuration, the first partition has a disk portion protruding in an arc shape corresponding to the trajectory of the movable end of the ball joint mechanism at the tip thereof, while the second partition has the same shape. It has a notch portion cut out in an arc shape corresponding to the shape of the disk portion. Accordingly, it is possible to prevent the operation of the ball joint mechanism from being hindered by the collision between the first partition and the second partition in the rolling vibration of the engine.

Since the second partition is cut out in correspondence with the shape of the disk, the combustion gas divided into two between the first partition and the second partition is separated. Merging and mutual interference are also minimized. Thereby, the flow of the combustion gas from the engine is promoted, and the performance of the engine is improved.

According to a third aspect of the present invention, in the exhaust system for an internal combustion engine according to the first or second aspect, the catalyst converter purifies a combustion gas discharged from the engine during a cold period immediately after the start of the engine. The gist is that it is a list.

According to the above configuration, the combustion gas discharged during the cold immediately after the start of the engine is purified. According to a fourth aspect of the present invention, in the exhaust system for an internal combustion engine according to any one of the first to third aspects, an exhaust pipe connected to the ball joint mechanism is an exhaust manifold. .

According to this configuration, the ball joint mechanism is directly connected to the exhaust manifold without an extra exhaust pipe. Therefore, the catalytic converter connected to the ball joint mechanism is provided at a position even closer to the engine. Thus, as described above, the time required for the catalytic converter to function becomes shorter, and the load applied to each component of the exhaust device by the catalytic converter is further reduced.

According to a fifth aspect of the present invention, there is provided a catalytic converter connected to a movable end of a ball joint mechanism via an upstream guide member, wherein the upstream guide member has a trajectory of the movable end of the ball joint mechanism. The gist of the present invention is to provide a partition having a cutout portion cut out in an arc shape corresponding to the above, and dividing the inside of the catalytic converter into two.

According to this configuration, the upstream guide member of the catalytic converter has a partition that divides the inside of the catalytic converter into two, and the partition corresponds to the locus of the movable end of the ball joint mechanism. It has a notch cut out in an arc shape. In a case where such a catalytic converter is rotatably connected to an exhaust pipe of an internal combustion engine via a ball joint mechanism, the inside of the fixed end of the exhaust pipe and the fixed end of the ball joint mechanism is different from the above. In the case where the inside is divided into two by the partition and the other partition is provided with a disk part protruding in an arc corresponding to the trajectory of the movable end of the ball joint mechanism at the tip thereof,
In the rolling vibration of the engine, it is possible to prevent the operation of the ball joint mechanism from being hindered by the collision of the partition wall with the another partition wall.

In the case of the above-mentioned connection, it is also possible to minimize the possibility that the combustion gas divided into two parts between the above-mentioned partition wall and the above-mentioned another partition wall will merge and interfere with each other. Thereby, the flow of the combustion gas from the engine is promoted, and the performance of the engine is improved.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in an exhaust device and a catalytic converter of a four-cylinder engine for an automobile will be described below with reference to FIGS.

FIG. 1 is a schematic diagram showing an automobile 1 to which an exhaust device and a catalytic converter of this embodiment are applied, an engine 2 thereof, and various parts of an exhaust system of the engine 2. In FIG. 1, an exhaust system of an engine 2 mounted on an automobile 1 is provided with an exhaust manifold 3.
A start catalyst 4 as a catalytic converter is connected to a downstream side of the exhaust manifold 3 via a ball joint mechanism described later. The start catalyst 4 is for quickly purifying harmful gases in the combustion gas discharged from the engine 2 in a cold state immediately after the start of the engine 2. Generally, in order for a catalytic converter to function, it must be heated to a predetermined temperature or higher. The above start catalyst 4
So that it can be warmed up as soon as possible by the combustion gas,
Close to engine 2 (exhaust manifold 3)
It is connected to the.

Downstream of the start catalyst 4, a main converter 6 is connected via an exhaust pipe 5.
Is connected. The main converter 6 is for purifying most of the harmful gas in the combustion gas discharged from the engine 2 when the engine 2 is warm.

A sub-muffler 8 is connected to the downstream side of the main converter 6 via an exhaust pipe 7. Further, further downstream of the sub-muffler 8, a main muffler 10 is connected via an exhaust pipe 9.
Is connected. These mufflers 8 and 10 are for canceling the pressure fluctuation of the energy of the explosion sound of the combustion gas to achieve a silent sound.

In the exhaust system configured as described above,
The combustion gas discharged from the engine 2 flows through the exhaust manifold 3, the start catalyst 4, the exhaust pipe 5, the main converter 6, the exhaust pipe 7, the sub-muffler 8, the exhaust pipe 9, and the main muffler 10, and is discharged to the outside. . The combustion gas flowing in this manner is purified of the harmful gas in the start catalyst 4 and the main converter 6, and is silenced in the sub muffler 8 and the main muffler 10.

Next, the exhaust manifold 3, the start catalyst 4, and its peripheral structure will be described with reference to FIG.
It will be described based on. On the upstream side of the exhaust manifold 3, four branch pipes 3a, 3b, 3c and 3d are formed corresponding to the four cylinders # 1, # 2, # 3 and # 4, respectively. Among these branch pipes 3a to 3d, the branch pipe 3a and the branch pipe 3d communicate with each other on the downstream side, while the branch pipe 3b and the branch pipe 3c communicate with each other on the downstream side. The downstream side of the exhaust manifold 3 is formed to have a substantially elliptical cross section.
e form two exhaust passages E1 and E2. Therefore, the branch pipes 3a and 3d communicate with the exhaust passage E1, and the branch pipes 3b and 3c communicate with the exhaust passage E2. The reason why the downstream side of the exhaust manifold 3 is divided into two groups of cylinders is to efficiently discharge the combustion gas. In the case of the engine 2 having four cylinders, the ignition order is the cylinder # 1,
The order is cylinder # 3, cylinder # 4, cylinder # 2. Therefore, in order to efficiently discharge the combustion gas, a group is formed by combining cylinders (cylinders # 1 and # 4, cylinders # 2 and # 3) that discharge the combustion gas at non-adjacent timings. Reduces gas mutual interference.

The exhaust manifold 3 and the start catalyst 4 are connected via a ball joint mechanism 31. This ball joint mechanism 31
As described later, the exhaust manifold 3 and the start catalyst 4 are rotatably connected to each other as described later. Therefore, the rolling vibration of the engine 2 is rotationally absorbed by the ball joint mechanism 31 and transmitted to the downstream side.

The start catalyst 4 includes an upstream guide member 4a, a catalyst carrier accommodating member 4b, and a downstream guide member 4c. Upstream guide member 4
The diameter of a is increased from the upstream side to the downstream side of the combustion gas. Further, the diameter of the downstream guide member 4c is reduced from the upstream side to the downstream side of the combustion gas. Therefore, the combustion gas from the upstream side flows into the upstream side guide member 4a while increasing the cross-sectional area of the passage.
b, and the downstream guide member 4c is further guided downstream while the passage cross-sectional area is reduced.

The inside of the upstream guide member 4a is divided into two by a separation plate 11 provided corresponding to the position of the partition wall 3e. Therefore, the combustion gas composed of the two groups as described above is guided into the catalyst carrier accommodating member 4b while maintaining the same state inside the upstream guide member 4a.

The catalyst carrier accommodating member 4b is buffered by, for example, a catalyst carrier holding mat 13 made of alumina fiber, for example, a monolithic catalyst carrier 1 made of ceramic.
4 are accommodated. The monolithic catalyst carrier 14 is provided with regular holes in the flow direction of the combustion gas. Therefore, the combustion gas flowing through the inside of the upstream guide member 4a divided into two parts is separated by the catalyst carrier housing member 4a.
Also inside b, it flows in a state of being largely divided into two groups for each of these holes, and is guided to the downstream side guide member 4c.

The downstream guide member 4c is divided into two parts by a similar separation plate 15 provided corresponding to the position of the separation plate 11. Therefore, the combustion gas flows inside the downstream guide member 4c in a state of being separated into two groups, and is guided to the exhaust pipe 5.

The inside of the exhaust pipe 5 is divided into two parts by a partition 16 provided corresponding to the position of the separation plate 15. As described above, this exhaust pipe 5
The main converter 6 is connected downstream of the main converter. Therefore, before this main converter 6, the combustion gas flows in a state of being separated into two groups. In addition,
Although illustration is omitted, the above-described 2
Combustion gases that have been separated into two groups merge. Then, the combustion gas integrally flows to the downstream side.

Next, the structure of the exhaust manifold 3, the ball joint mechanism 31, and the start catalyst 4 in this embodiment will be described in more detail with reference to FIG.

FIG. 3A is a sectional view of the exhaust manifold 3, the ball joint mechanism 31, and the start catalyst 4, and FIG. 3B is a sectional view taken along line BB of FIG. 3A. FIG.

As shown in FIG. 3A, the ball joint mechanism 31 includes an upstream flange 32 fixed to a downstream end of the exhaust manifold 3 by welding W1, and an upstream side of the upstream guide member 4a. A downstream flange 33 as a spherical member directly fixed to the end by welding W2 is provided, and a bolt 35 for connecting the flanges 32 and 33 is provided. The downstream flange 33 is formed with a spherical portion 33a whose inner diameter is reduced along a spherical shape having a predetermined curvature. And this spherical part 3
Between the exhaust manifold 3 and the exhaust manifold 3, a gasket 34 formed according to the shape of the spherical surface portion 33a is interposed. The gasket 34 prevents the combustion gas from leaking between the exhaust manifold 3 and the start catalyst 4 (upstream guide member 4a).

A spring 36 is interposed between the bolt head 35a of the bolt 35 and the downstream flange 33 with a predetermined elastic force. The bolt 3
The fifth screw portion 35b is fastened to the boss portion of the upstream flange 32.

At the end of the partition wall 3e in the present embodiment, as shown in FIGS. 3 (a) and 3 (b), a disk portion 37 is formed to match the spherical shape formed by the spherical portion 33a. I have. On the other hand, a notch 38 is formed at the end of the separating plate 11 in accordance with the shape of the disk 37.

In such a shape, between the exhaust manifold 3 and the start catalyst 4, the contact surface between the gasket 34 and the spherical portion 33a slides with each other so as to be rotatable. Becomes This allows
The rolling vibration transmitted from the engine 2 to the exhaust manifold 3 is applied to the downstream upstream guide member 4a on the downstream side.
(Start catalyst 4) is suppressed. The energy of the rolling vibration is reduced by the elastic deformation of the spring 36.

The spherical portion 33a is provided on the partition wall 3e.
Is formed in accordance with the spherical shape formed by
Since the notch portion is formed in the separation plate 11 according to the shape of the disk portion, even when the space between the exhaust manifold 3 and the start catalyst 4 rotates due to the rolling vibration, The partition wall 3e collides with the separation plate 11, and the ball joint mechanism 31
Is prevented from being hindered. Furthermore, since the notch portion 38 is formed in accordance with the shape of the disk portion 37, the merge of the combustion gas between the partition wall 3e and the separation plate 11 is suppressed to a minimum.

As described in detail above, according to the present embodiment, the following effects can be obtained. (1) The ball joint mechanism 31 is provided on the exhaust manifold 3, and the start catalyst 4 is connected to the exhaust manifold 3 without an extra exhaust pipe. Therefore, the start catalyst 4 can be provided at a position closer to the engine 2. Thereby, the start catalyst 4 can be heated more quickly by the combustion gas from the engine 2. That is, the time until the start catalyst 4 functions can be shortened. Then, the harmful gas in the combustion gas at the time of starting the engine can be reduced.

(2) Since the heavy start catalyst 4 is provided closer to the engine 2, the load applied to the exhaust manifold 3 and the ball joint mechanism 31 by the start catalyst 4 is reduced. can do.

(3) Even when the exhaust manifold 3 and the start catalyst 4 rotate due to the rolling vibration, the partition wall 3e collides with the separation plate 11 and the ball joint mechanism 31 The operation can be prevented from being hindered. In addition, since the notch 38 is formed in accordance with the shape of the disk 37,
Combining of the combustion gas between the partition wall 3e and the separation plate 11 can also be suppressed to a minimum. Thereby, the flow of the combustion gas from the engine 2 is promoted, and the performance of the engine 2 can be improved.

(4) In order to reduce the influence of the mutual interference of the combustion gases, the exhaust system of the engine 2 is divided into two groups. Therefore, the combustion gas can be efficiently discharged to the outside, and the output of the engine 2 can be improved.

The present embodiment is not limited to the above, but may be modified as follows. In the present embodiment, the upstream flange 32 and the exhaust manifold 3 are provided separately, but they may be formed integrally.

In the present embodiment, the downstream flange 33 and the upstream guide member 4a are provided as separate bodies, but they are provided along the line BB in FIGS. 4 (a) and 4 (a). As shown in FIG. 4B, which is a cross-sectional view of FIG. In this case, the number of parts can be reduced.

In the present embodiment, the ball joint mechanism 31 (upstream flange 32) is directly connected to the exhaust manifold 3, but an appropriate exhaust pipe is connected to the exhaust manifold 3, and the ball joint mechanism 31 is connected to the exhaust pipe. You may make it connect.

In this embodiment, the inside of the exhaust manifold 3, the start catalyst 4, and the exhaust pipe 5 are partitioned by the partition 3e, the separator 1
Although they are divided into two by the partition walls 1 and 15 and the partition wall 16, they need not necessarily be divided into two.

In the present embodiment, a configuration including the start catalyst 4 and the main converter 6 is adopted, and the exhaust device and the catalytic converter according to the present invention are applied to the start catalyst 4 and its peripheral structure. On the other hand, when a configuration including only the main converter is adopted, the exhaust device and the catalytic converter according to the present invention may be applied to the main converter and its peripheral structure.

[0047]

As described above in detail, according to the first aspect of the present invention, the catalytic converter can be heated more quickly by the combustion gas from the internal combustion engine, and the time required for the catalytic converter to function can be shortened. Thereby, the harmful gas in the combustion gas after the engine is started can be reduced.

Further, the load applied to each component of the exhaust system by the catalytic converter can be reduced. According to the invention described in claim 2, in the rolling vibration of the engine, the collision between the first partition and the second partition causes
The operation of the ball joint mechanism can be prevented from being hindered.

Further, it is possible to minimize the interference of the divided combustion gases between the first partition wall and the second partition wall and to interfere with each other. Thereby, the flow of the combustion gas from the engine is promoted, and the performance of the engine can be improved.

According to the third aspect of the present invention, it is possible to purify the combustion gas discharged during the cold immediately after the start of the engine.
According to the fourth aspect of the present invention, the time required for the catalytic converter to function can be shortened, and the load applied to each component of the exhaust device by the catalytic converter can be further reduced.

According to the fifth aspect of the present invention, the catalytic converter is rotatably connected to the exhaust pipe of the internal combustion engine via the ball joint mechanism, and the fixed end of the exhaust pipe and the ball joint mechanism is fixed. Is divided into two parts by another partition wall different from the above, and the other partition wall has a disk portion protruding in an arc shape at the tip thereof corresponding to the trajectory of the movable end of the ball joint mechanism. In this case, it is possible to prevent the operation of the ball joint mechanism from being hindered by the collision between the catalytic converter and the partition wall of the exhaust pipe during the rolling vibration of the engine.

Further, it is also possible to minimize the interference of the two divided combustion gases with each other between the two partition walls. Thereby, the flow of the combustion gas from the engine is promoted, and the performance of the engine can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an outline of an engine and an exhaust system to which an embodiment of an exhaust device and a catalytic converter of the present invention is applied.

FIG. 2 is a partial cross-sectional view showing a structure of an exhaust manifold, a ball joint mechanism, a start catalyst, and the like to which the embodiment is applied;

FIG. 3 is a sectional view showing the structure of the exhaust device and the catalytic converter of the embodiment.

FIG. 4 is a sectional view showing another configuration example of the exhaust device according to the present invention.

FIG. 5 is a perspective view showing an outline of a conventional exhaust device.

[Explanation of symbols]

2 ... Engine, 3 ... Exhaust manifold, 3e ...
Partition wall, 4 ... start catalyst, 4a ... upstream guide member, 4b ... catalyst carrier accommodating member, 4c ... downstream guide member, 11 ... separation plate, 14, monolith catalyst carrier, 31 ...
Ball joint mechanism, 32 ... Upstream flange, 33 ...
Downstream flange, 33a: spherical part, 34: gasket,
37: disk part, 38: notch part.

Claims (5)

[Claims] 1. A catalytic converter accommodating a monolithic catalyst carrier therein and having guide members on upstream and downstream sides, and a ball joint mechanism for rotatably connecting the catalytic converter to an exhaust pipe of an internal combustion engine. An exhaust device for an internal combustion engine, wherein a movable end of the ball joint mechanism is directly attached to the upstream guide member of the catalytic converter. 2. The fixed end of the exhaust pipe and the ball joint mechanism is internally divided into two parts by a first partition, and the first partition has a movable end of the ball joint mechanism at a tip end thereof. A disk portion protruding in an arc shape corresponding to the trajectory, wherein the upstream guide member of the catalytic converter has a notch portion cut out in an arc shape corresponding to the disk shape of the first partition wall. The exhaust device for an internal combustion engine according to claim 1, further comprising a second partition having a second partition for dividing an inside of the catalytic converter into two. 3. The exhaust device for an internal combustion engine according to claim 1, wherein the catalytic converter is a start catalyst that purifies combustion gas discharged from the engine during a cold period immediately after the start of the engine. 4. The exhaust device for an internal combustion engine according to claim 1, wherein the exhaust pipe connected to the ball joint mechanism is an exhaust manifold. 5. A catalytic converter connected to a movable end of a ball joint mechanism via an upstream guide member, wherein the upstream guide member has an arc shape corresponding to a locus of the movable end of the ball joint mechanism. A catalytic converter having a cut-out portion formed therein and having a partition wall for dividing the inside of the catalytic converter into two parts.