JPS6130126B2 - - Google Patents

Description

[Detailed description of the invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalytic converter device installed in the exhaust system of an automobile engine to purify harmful components in exhaust gas.

[Conventional technology]

By the way, in the conventional catalytic converter, a wire mesh is wound around the outer periphery of a cylindrical catalyst carrier with an elliptical cross section, and damper meshes are applied to the periphery of both ends of the wire mesh, and this is elastically inserted into the catalyst shell, which has an elliptical cross section. Further, elastic compression in the axial direction of the damper mesh in this case provides a gas seal to prevent exhaust gas from leaking to the wire mesh side. Also, as an example of prior art regarding this,
No. 51-34528 discloses that a catalyst carrier having a wire mesh wound around the outer periphery is housed in a cylindrical catalyst shell, and on both sides of the shell, the inner end portions are fitted onto the inner circumferential surface of the catalyst shell. A cone-shaped gas inlet member and an outlet member each having an exhaust gas inlet and an outlet at the outer ends are provided, and between the catalyst carrier and these members, the inner end is fitted onto the catalyst carrier. A bellows-shaped annular body made of a heat-resistant material is interposed, the outer end of which presses against each of the members, thereby elastically supporting the catalyst carrier within the catalyst shell, and in particular, supporting the catalyst carrier against the shell on the inlet side of the catalyst carrier. A device designed to provide a gas seal is described.

[Problems to be solved by the invention]

By the way, especially in a catalytic converter to which multiple exhaust pipes are connected, the catalyst carrier has a cylindrical shape with an elliptical cross section, and the catalyst shell that houses it also has a cylindrical shape with an elliptical cross section, so it is important to maintain dimensional accuracy. It's difficult. Particularly when the catalyst shell is divided in half to form multiple gas inlet ports, it is difficult to always keep the overall dimensions constant when integrated into a cylinder, and this makes it difficult to keep the overall dimensions of the catalyst carrier and catalyst This causes variations in the distance between the shell and the shell. Therefore, in the narrow annular damper mesh that is assembled to the end of the wire mesh, it is not possible to ensure that the inner circumferential surface of the damper mesh comes into contact with the outer circumferential edge of the catalyst carrier, and it is difficult to expect sufficient and reliable sealing performance at all times. I can't. In addition, the single damper mesh on the inlet side of the catalyst carrier is forced to undergo harsh use, supporting and sealing the catalyst carrier while being exposed to high-temperature exhaust gas containing harmful components, which can lead to premature deterioration. This results in problems such as a shortened lifespan of the catalytic converter. As described above, the present invention has a catalyst shell formed by joining a pair of half-split shells against each other.
In a catalytic converter in which a catalyst carrier is accommodated and supported within a catalyst shell, which makes it relatively easy to assemble the catalyst carrier, the gas seal at the inlet end of the catalyst carrier is replaced by a bellows with a complicated structure as in the prior art example described above. The purpose of this invention is to achieve this economically by using a seal ring with a simple structure without using a shaped annular body, and thereby to solve the aforementioned problems such as early deterioration of the damper mesh and shortening of the life of the catalytic converter. .

[Means to solve the problem]

In order to achieve this object, the present invention collects the exhaust port openings of a plurality of cylinders in opposing left and right rows into one exhaust passage, as seen in horizontally opposed engines, and furthermore, This assumes an exhaust system in which the exhaust pipes are gathered in the middle and communicated with the muffler, and a catalytic converter is placed at the point where the exhaust pipes meet in the exhaust system, and multiple exhaust pipes on the upstream side are connected. The catalytic converter is connected to the inlet side of the catalytic converter, and the downstream exhaust pipe is connected to the gas outlet side on the opposite side, so the catalytic shell of the converter is
It consists of a pair of half-shells, which are butt-joined together to house and support the catalyst carrier inside, and a plurality of gas inlet ports are formed on the joint surface at one end. , an outlet port is formed on the joint surface at the other end, and a plurality of upstream exhaust pipes are connected to the plurality of gas inlet ports, and a downstream exhaust pipe is connected to the outlet port. The cylindrical part of the seal ring is adhered to the inlet side end of the catalyst carrier so that it has a specified outer diameter, and damper meshes for exhaust gas sealing are attached to the outer periphery and the outer periphery of the catalyst carrier at both ends. The assembled wire mesh is wound around the halved shell to elastically support the catalyst carrier within the catalyst shell through elastic compression, and the entire circumference of the tip of the lip extending toward the exhaust port side of the seal ring. is elastically deformed and is airtightly crimped onto the inner surface of the tapered portion of the half shell.

[Effect]

In the above-mentioned means, a cylindrical part of a seal ring is connected to the inlet side end of the catalyst carrier so as to have a specified outer diameter, and an exhaust gas seal is provided on the outer periphery and the outer periphery of the catalyst carrier at both ends. Wrap the wire mesh with the damper mesh attached,
The catalyst carrier is elastically supported within the catalyst shell by elastic compression by the half shell, and the entire circumference of the tip of the lip extending toward the exhaust port side of the seal ring is elastically deformed, thereby reducing the taper of the half shell. Since the catalyst carrier is crimped to the inner surface of the part, it is difficult to achieve dimensional accuracy due to its elliptical cylindrical cross section, and the catalyst carrier can absorb the variation in dimensions between the pair of catalyst shells. The wire mesh and the damper mesh are supported elastically and immovably via the damper mesh, and the wire mesh and damper mesh ensure gas sealing against the inlet side of the catalyst carrier, preventing early deterioration of the catalyst carrier, thereby extending the life of the catalytic converter. can be extended over a long period of time.

【Example】

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings. As shown in FIG. 1, the exhaust system of an automobile engine to which the catalytic converter device according to the present invention is applied has two or more exhaust ports from the left and right cylinders of the engine body 1, such as a horizontally opposed engine. Exhaust pipes 2 and 3 are 1 in the middle
It is assumed that the exhaust system is assembled into a book and connected to an exhaust pipe 4 leading to a muffler (not shown), and the two exhaust pipes 2 and 3 on the upstream side of such an exhaust system and the two exhaust pipes on the downstream side are used. A catalytic converter 5 is assembled at a meeting point with the exhaust pipe 4. Thus, the upstream exhaust pipes 2 and 3 are connected to the inlet side of the catalytic converter 5, and the downstream exhaust pipe 4 is connected to the outlet side thereof, and the two upstream exhaust pipes 2 and 3 are connected to the catalytic converter 5. The exhaust pipes 4 are collected together through the exhaust pipe 4 on the downstream side. As shown in FIGS. 2 to 6, the catalytic converter 5 has a honeycomb-shaped catalyst carrier 6 housed in a cylindrical catalyst shell 7 with an elliptical cross section, and the catalyst is made of a single structure made of fire-resistant ceramic. It is a three-way catalyst in the body. As shown in FIG. 4, the catalyst shell 7 consists of two component parts: a pair of upper and lower bowl-shaped half shells 71 and 72, which are made of stainless steel with excellent heat resistance and corrosion resistance.・It is made by processing plate materials such as steel into sheet metal. The pair of upper and lower half shells 71 and 72 are formed symmetrically with each other, and the body portion 7 has a semi-elliptical cross section.
A tapered part 7 having a semi-funnel cross section on one side of 1a and 72a.
1b, 72b are integrally molded, and two cylinder openings 71c, 71d and 72c, 72d each having a semicircular cross section are integrally molded at one end of each of the tapered portions 71b, 72b. A cylinder opening 71 is provided on the side opposite to the tapered portions 71b and 72b.
e and 72e are integrally molded. Then, by butting these half shells 71 and 72 together, the body 7 is assembled.
A catalyst storage chamber 8 is formed by 1a and 72a, a gas rectification chamber 9 is formed by tapered parts 71b and 72b, and two gas inlet ports 10 and 11 are formed by cylinder ports 71c and 71d and 72c and 72d,
The outlet port 15 is formed by the cylinder openings 71e and 72e. gas inlet port 10,
11 is opened diagonally outward with respect to the axial center lines of the body parts 71a and 72a so that their axial center lines intersect with each other on the inlet side of the catalyst storage chamber 8, The outlet port 15 is opened so as to be offset to one side with respect to the axial center line of the body. When joining the half shells 71 and 72 to each other, the catalyst carrier 6 is assembled into the body portion 71a of one of the half shells 71, for example, in the previous half state. During assembly, a seal ring 24 (described later) is fitted and adhered to the gas inlet side end of the catalyst carrier 6 in advance, and a wire mesh 12 is further wound around the outer periphery. Damper meshes 13 and 14 are integrally assembled at both ends of the wire mesh 12.
By wrapping the wire mesh 12 around the outer periphery of the catalyst carrier 6, one of the damper meshes 13 is fitted to the outer periphery of the seal ring 24, and the other damper mesh 14 is fitted to the gas outlet side end of the catalyst carrier 6. be done. In this state, the catalyst carrier 6 is pushed into the body 71a of the half shell 71 so that the damper meshes 13 and 14 are sandwiched between the step portions 71f and 71g at both ends of the body 71a of the half shell 71. As a result, both the wire mesh 12 and the damper meshes 13 and 14 are elastically compressed, and the lower half of the catalyst carrier 6 is housed and supported inside the body 71a of the half shell 71 so as not to move in the axial and radial directions. Ru. After storing in this way, the upper half of the catalyst carrier 6 is accommodated and supported by covering it with another half shell 72, and in this state, by welding the periphery of the half shells 71 and 72, A pair of half-split shells 7
1 and 72 are integrated like a shell. In addition, the half shells 71, 7 on the inlet side of the catalyst carrier 6
As mentioned above, there is a seal ring 24 between
is installed, but this seal ring 24 is attached to the seventh
As shown in detail in the figure, a lip portion 24b extending toward the exhaust port is attached to one end of an elliptical tube portion 24a formed so as to be fitted into the catalyst carrier 6, so as to be approximately horizontal so that it can be elastically bent. The cylindrical portion 24a is formed to protrude and is formed to have a specified outer diameter l. Further, such a seal ring 24 is manufactured by applying ceramic cement 25 to the outer circumferential surface of the inlet side end of the catalyst carrier 6, and then sealing the cylindrical portion 24 of the catalyst carrier 6.
a is fitted and bonded, so that even if there is variation in the outer diameter of the catalyst carrier 6, the variation is corrected because the cylindrical portion 24a of the seal ring 24 has a specified outer diameter l. When the catalyst carrier 6 to which the seal ring 24 is adhered is housed in, for example, one of the half shells 71 which is split in half in the manner described above, the lip portion 24 of the seal ring 24 protruding from the catalyst carrier 6
The lower half of the tip of b is bent and press-fitted to the inner surface of the tapered part 71b of the half shell 71, and when the half shell 71 is covered with another half shell 72, the tapered part 72b of the half shell 72 is bent. Rip part 24b also on the inner surface
The upper half of the tip is bent and crimped. In this way, the seal ring 24 has its cylindrical portion 24a adhered to the catalyst carrier 6, and the entire circumference of the tip of the lip portion 24b is attached to the inner surface of the tapered portions 71b, 72b of the half shells 71, 72 which are butt-jointed. By press-fitting, a particularly strong gas sealing property is ensured between the inlet side of the catalyst carrier 6 and the half shells 71, 72. In this way, the catalyst carrier 6 is elastically housed and supported inside the half shells 71 and 72 by the wire mesh 12 and the damper meshes 13 and 14 so as not to move, and the seal ring 24 is placed between the wire mesh 12 and the damper meshes 13 and 14. The inlet side of the catalyst carrier 6 and the half shells 71 and 72 are also brought into close pressure contact to ensure gas sealing.
The upstream exhaust pipe 2,
The catalytic converter 5 is assembled to the collecting part of the exhaust system by inserting and joining the pipe ends of the exhaust pipes 3 and 3 and joining the downstream exhaust pipe 4 to the outlet port 15. The catalytic converter 5 also has a pair of upper and lower protective covers 16, 1 surrounding the outer periphery of the shell 7.
7 is installed. These protective covers 16,1
As is clear from FIGS. 1, 2, 3, 5, and 6, 7 has a shape that is approximately similar to half the overall shape of the catalyst shell 7, and has three outer peripheral portions 18,
Restrictions 19 and 20 into which the exhaust pipes 2, 3 and 4 fit are provided, and are fixed to the catalyst shell 7 with bolts 21 at these locations. Note that the upper and lower protective covers 16 and 17 are spaced apart from each other at a predetermined distance at the upper and lower mating parts over substantially the entire circumference except for the above-mentioned three fixed parts, and an opening 22 through which air passes is formed there. In addition to protecting the catalyst shell 7, it also serves as an air cooling function. Furthermore, outlet port 1
A temperature sensor 23 is attached near 5. A catalytic converter device according to an embodiment of the present invention includes:
With the above-described configuration, the exhaust gas discharged from the left and right cylinders of the engine main body 1 passes through the two exhaust pipes 2 and 3 alternately at predetermined exhaust timing, and then enters the inlet port 10 of the catalytic converter 5. 11
From then on, it enters the catalyst shell 7. At this time, the inlet ports 10 and 11 are opened diagonally outward with respect to the axial center line of the shell 7 so that their axial center lines intersect with each other inside the inlet of the shell 7. Inlet port 10,1
Exhaust gas entering the catalyst shell 7 from the catalyst shell 7 is mixed in the gas rectifying chamber 9 inside the inlet, and is diagonally diffused and collides with the inlet side end face of the catalyst carrier 6 housed inside. become. As a result, the gas flow becomes turbulent inside the gas rectification chamber 9, its flow velocity decreases, and the time taken for the gas to pass through the catalyst carrier 6 becomes longer. Furthermore, on the outlet side, since the outlet port 15 is open to one side with respect to the axial center line of the shell 7, the passage of gas is also suppressed.
Overall, the passage time of the gas passing through the catalyst carrier 6 is ensured for a long time. On the other hand, the inlet side of the catalyst carrier 6 and the half shell 71,
Seal ring 24 provided between
The cylindrical portion 24a has a specified outer diameter, and the cylindrical portion 24a of the seal ring 24 is fitted and bonded to the outer periphery of the inlet end of the catalyst carrier 6, so that the outer diameter of the catalyst carrier 6 is There is no variation in the dimensions, and the lip portion 24b has the same shape as the outer half shell 71,
By elastically crimping the inner surfaces of the half shells 71 and 72, variations in the dimensions of the half shells 71 and 72 are eliminated.
will be bent and absorbed accordingly. Further, due to such a seal ring, the damper mesh 13 at the inlet side end of the catalyst carrier 6 is not exposed to exhaust gas, and therefore early deterioration is prevented and gas sealing performance is ensured. All of the exhaust gas flowing into the exhaust gases 71 and 72 is always guided to the catalyst carrier 6, and mixing in the gas rectification chamber 9 is performed smoothly without loss.

【Effect of the invention】

Thus, according to the present invention, while the exhaust gas passes through the catalyst carrier 6, sufficient gas passage time necessary for the oxidation reaction and reduction reaction is ensured,
Since the oxidation action of CO and HC and the reduction and separation action of NOx are sufficiently promoted, even a honeycomb type catalytic converter can demonstrate its purification performance to the maximum. In addition, the inlet side of the catalyst carrier 6 and the half shells 71, 7
2, a seal ring 24, which has a simpler structure than the bellows-shaped annular body in the prior art example described above, has a high temperature, and is strong against exhaust gas containing harmful components, is interposed, and this is elastically deformed to close the shell 7.
The damper mesh 13 at the inlet side end of the catalyst carrier 6 is pressed against the inner surface of the catalyst carrier 6 and the half shells 71, 72 to absorb the variation in dimensions between the catalyst carrier 6 and the half shells 71, 72. It is possible to economically ensure good gas sealing performance at all times without being exposed to gas, preventing early deterioration and extending the life of the catalytic converter. Assembling the catalyst carrier 6 and the like becomes easy. Further, although the seal ring 24 covers a part of the inlet side end face of the catalyst carrier 6, it does not completely block it, so the reaction area in the catalyst carrier 6 becomes wider than in the case of only a damper mesh.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing one embodiment of a catalytic converter device according to the present invention, FIG. 2 is a cross-sectional plan view showing an enlarged portion of the catalytic converter device, FIG. 3 is a side view of the same, and FIG. An exploded perspective view of the catalyst shell of the catalytic converter device, FIG. 5 is a sectional view taken along the - line in FIG. 2, and FIG.
FIG. 7 is a cross-sectional view taken along the line, and is an enlarged cross-sectional view of section A in FIG. 2. 1... Engine body, 2, 3... Upstream exhaust pipe, 4... Downstream exhaust pipe, 5... Catalytic converter, 6... Catalyst carrier, 7... Catalyst shell, 8...
Catalyst storage chamber, 9... Gas rectification chamber, 10, 11...
Inlet port, 12...Wire mesh, 13,1
4... Damper mesh, 15... Exit port, 1
6, 17...Protective cover, 18, 19, 20...
Part, 21... Bolt, 22... Opening, 23...
Temperature sensor, 24... Seal ring, 24a...
Cylinder part, 24b... Lip part, 25... Ceramic cement, 71, 72... Half shell.

Claims (1)

[Claims] 1. In an exhaust system in which a plurality of exhaust pipes extending from the exhaust port of an engine are collected into one pipe in the middle and communicated with a muffler, a catalytic converter is disposed at the joint part of the exhaust pipes, and the catalytic converter has a catalytic converter. The shell consists of a pair of half-shells that are split into two, and the pair of half-shells are butt-jointed together and a catalyst carrier is housed and supported inside, thereby providing multiple gas inlets on the joint surface at one end. A port is formed,
An outlet port is formed on the joint surface of the other end, and a plurality of upstream exhaust pipes are connected to the plurality of gas inlet ports, and a downstream exhaust pipe is connected to the outlet port. A cylindrical portion of a seal ring is adhered to the inlet side end of the catalyst carrier so as to have a specified outer diameter, and damper meshes for exhaust gas sealing are provided at both ends on the outer periphery of the seal ring and on the outer periphery of the catalyst carrier. The assembled wire mesh is wound around the halved shell to elastically support the catalyst carrier within the catalyst shell through elastic compression, and the entire circumference of the tip of the lip extending toward the exhaust port side of the seal ring. A catalytic converter device for purifying automobile exhaust gas, characterized in that the catalytic converter device is elastically deformed and hermetically bonded to the inner surface of the tapered portion of the half shell.