JPS6130127B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

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, conventionally, a catalytic converter is constructed by wrapping a wire mesh around the outer periphery of a catalyst carrier having an elliptical cross section, and applying damper meshes to the periphery of both ends of the wire mesh so that the catalyst carrier is elastically housed and supported inside a catalyst shell having an elliptical cross section. Further, in this case, elastic compression of the damper mesh in the axial direction provides a gas seal to prevent exhaust gas from leaking to the wire mesh side. In addition, as an example of prior art related to this, Japanese Patent Application Laid-Open No. 49
-13076 and Japanese Patent Publication No. 51-34528. According to the former, a cylindrical shape is formed by combining a pair of half shells with semicircular cross sections and welding their flanges. A catalyst carrier with a holding member and a sealing member wrapped around the outer periphery is housed in the catalyst shell, and a plurality of ring-shaped grooves are provided along the axial direction on the outer periphery of the catalyst shell, so that the axial direction of the holding member and sealing member is According to the latter, a catalyst carrier having a wire mesh wound around the outer periphery is housed in a cylindrical catalyst shell, and inner ends are formed on both sides of the shell. A cone-shaped gas inlet member and an outlet member are provided which fit onto the inner circumferential surface of the catalyst shell and have an exhaust gas inlet and an outlet at outer ends, respectively, and an inner end is provided between the catalyst carrier and these members. A bellows-shaped annular body made of a heat-resistant material is interposed, the outer end of which fits onto the catalyst carrier and whose outer end comes into pressure contact with the above-mentioned member, thereby elastically supporting the catalyst inner body within the catalyst shell, and supporting the catalyst carrier. A gas seal is provided at the inlet end of the pipe.

[Problems to be solved by the invention]

By the way, in a catalytic converter to which a plurality of exhaust pipes are connected, the catalyst carrier has a cylindrical shape with an elliptical cross section as described above, and the catalyst shell that houses it also has a cylindrical shape with an elliptical cross section. It is difficult to achieve dimensional accuracy in both cases. Particularly when the catalyst shell is divided into halves to form multiple gas inlet ports, it is difficult to always keep the overall dimensions constant when these are integrated into a cylindrical shape. This causes variations in the distance between the catalyst shell and the catalyst shell. Therefore, in the case of a narrow annular damper mesh, the inner circumferential surface cannot be brought into reliable contact with the outer circumferential edge of the catalyst carrier, and sufficient and reliable sealing performance cannot always be expected. Furthermore, on the inlet side of the catalyst carrier, a single damper mesh is forced to undergo harsh use as it performs the functions of both supporting and sealing the catalyst carrier while being exposed to high temperature exhaust gas containing harmful components. There are problems such as early deterioration and shortened life of the catalytic converter. The present invention is formed by butt-joining a pair of half-shells, and therefore, although it is difficult to achieve dimensional accuracy and dimensional variations occur, it has the advantage that it is easy to assemble the catalyst carrier. In the case of a catalyst shell with an elliptical cross section to which an exhaust pipe is connected, it is particularly important to have a catalytic converter that accommodates and supports a catalyst carrier of the same shape in the catalyst shell, which is easy to manufacture. Gas sealing can be performed economically using a seal ring with a simple structure without using a bellows-shaped circular body with a complicated structure as in the latter example of the prior art. The purpose is to solve problems such as shortening the lifespan of cars.

[Means to solve the problem]

In order to achieve this object, the device of the present invention provides an exhaust system in which a plurality of exhaust pipes extend from the exhaust port of the engine, and the plurality of exhaust pipes are gathered together in the middle and communicated with the muffler. The assumption is that a catalytic converter is placed at the exhaust pipe gathering part of this exhaust system, and multiple exhaust pipes on the upstream side are connected to the inlet side of the catalytic converter, and the downstream side is connected to the gas outlet side on the opposite side. In order to connect the exhaust pipes of the converter and equip it with a catalytic converter in this form, the catalyst shell of the converter consists of a pair of half-shells that have been split into two, and the pair of half-shells are integrated like a shell. a plurality of gas inlet ports are formed on the joint surface of one end thereof, and an outlet port is formed on the joint surface of the other end, and the plurality of gas inlet ports thus formed are A plurality of upstream exhaust pipes are connected to the catalyst carrier, and a downstream exhaust pipe is connected to the outlet port, and a seal ring is interposed between the inlet end of the catalyst carrier and the half shell, In addition, this seal rig joins a pair of half rings that have been split into two at a position away from the joining line of the outer half shell, and connects the cylindrical portions of these half rings to the inlet side end of the catalyst carrier. A wire mesh with a damper mesh for exhaust gas sealing attached to both ends is wrapped around the outer periphery of the shell and the outer periphery of the catalyst carrier, and the catalyst carrier is pushed into the shell by elastic compression by these half shells. The half ring is elastically supported, and almost the entire circumference of the tip of the lip on the exhaust port side of the half ring is elastically crimped onto the inner surface of the half shell, and further so as to protrude outward from the lip. It is characterized in that the peak portion formed in the above is fitted and crimped into the gap formed inside the half-shell joint portion.

[Effect]

In the above-mentioned means, a pair of half rings divided into two are interposed between the inlet side end of the catalyst carrier and the half shell, and these half rings connect the cylindrical part of the catalyst carrier to the half shell. A wire mesh fitted with the inlet side end and having damper meshes for exhaust gas sealing installed at both ends is wound around the outer periphery of the wire mesh and the outer periphery of the catalyst carrier, and the catalyst carrier is elastically compressed by these half shells. Since it is elastically supported within the catalyst shell and can absorb variations in dimensions between the catalyst carrier and the half shell, it is possible to ensure good gas sealing properties at the inlet end of the catalyst carrier. Furthermore, substantially the entire circumference of the tip of the lip on the exhaust port side of the half ring is elastically compressed against the inner surface of the half shell, and a peak portion is formed on the lip to protrude outward. is fitted and crimped into the gap created inside the half-shell joint, so the gas sealing effect is further improved and becomes almost complete. Therefore, the damper mesh at the inlet end of the catalyst carrier is No exposure to exhaust gases prevents premature deterioration, which in turn extends the life of the catalytic converter.

【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 within a catalyst shell 7 having a cylindrical shape with an elliptical cross-section, which is particularly difficult to achieve precision and tends to cause variations in dimensions. The catalyst is a three-way catalyst made of a single refractory ceramic structure. As shown in FIG. 4, the catalyst shell 7 consists of two constituent members: a pair of upper and lower bowl-shaped half shells 71 and 72, which are heat resistant. It is made by processing plate materials such as stainless steel with excellent corrosion resistance. The pair of upper and lower half shells 71, 72 are formed almost symmetrically to each other, and have tapered portions 71b, 72b each having a semi-funnel shape on one side of the body portions 71a, 72a having a semi-elliptical cross section. are integrally formed, and two cylindrical openings 71c, 71d and 72c, 72d each having a semicircular arc cross section are similarly integrally molded at one end of each of the tapered portions 71b, 72b,
Further, the tapered portions 71b, 72 of the body portions 71a, 72a
Cylinder openings 71e and 72e are integrally molded on the side opposite to b. And these half-split shells 71,7
2, a catalyst storage chamber 8 is formed by the body parts 71a and 72a, and the tapered parts 71b and 72b
The gas rectification chamber 9 is formed by the cylinder openings 71c, 7.
Two gas inlet ports 10, 11 are formed by 1d, 72c, and 72d, and an outlet port 15 is formed by cylinder ports 71e, 72e. The gas inlet ports 10 and 11 are opened diagonally outward with respect to the axial center lines of the bodies 71a and 72a so that their axial center lines cross each other on the inlet side of the catalyst storage chamber 8. The outlet port 15 is opened and deviated 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 inside the body portion 71a of one of the half shells 71, for example, when the half shells 71 and 72 are in the previous half state. During this assembly, a seal ring 24, which will be described later, is fitted in advance to the gas inlet side end of the catalyst carrier 6, and the wire mesh 12 is further wound around the outer periphery of the seal ring 24. This wire mesh 12 is integrally assembled with damper meshes 13 and 14 at both ends, and by wrapping the wire mesh 12 also around the outer periphery of the catalyst carrier 6, one of the damper meshes 13 is attached to the seal ring 24. The other damper mesh 14 is fitted to the gas outlet side end of the catalyst carrier 6. In this state, the damper meshes 13 and 14 are each attached to the body 7 of the half shell 71.
A catalyst carrier is sandwiched between the inlet end step 71f of the shell 71a and the seal ring 24, and between the outlet end step 71g of the body 71a and the catalyst carrier 6. 6 is pushed in, whereby both the wire mesh 12 and the damper meshes 13 and 14 are elastically compressed, and the lower half of the catalyst carrier 6 does not move in the axial and radial directions inside the body 71a of the half shell 71. It is elastically stored and supported. 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 shells 71 and 72 are integrated like a shell. In addition, the inlet side of the catalyst carrier 6 and the half shells 71, 7
As mentioned above, there is a seal ring 24 between the
As shown in detail in FIG. 8, this seal ring 24 consists of two constituent members: a pair of upper and lower half rings 241 and 242, which are divided into two halves. 242 has a semi-elliptical shape, and one half is shorter than the other half of the oval, and the other is longer than the half of the oval, so that when the upper and lower parts are joined, the outer half shells 71 and 72
Both ends are joined at a position shifted to one side from the joining line to form a closed ellipse. Further, these half rings 241 and 242 have cylindrical portions 241a and 242a that fit into the catalyst carrier 6,
It has lip portions 241b and 242b that protrude almost horizontally from one end toward the exhaust port side and elastically bend,
Lip portion 24 of one longer half ring 241
1b is formed with a peak portion 25 that protrudes outward and has an inverted V-shaped cross section at a location that coincides with the center line of the ellipse formed when these are joined. This peak 25 has a shape that matches the V-shaped gap formed inside the joint when the half shells 71 and 72 are joined, so that it can fit tightly into the gap. On the other hand, as shown in Figures 2, 4, and 7,
Tapered portions 71b, 72b of half shells 71, 72
, a stepped portion 71f at the boundary between the body portions 71a and 72a,
Annular protrusions 26 and 27 projecting inward are formed in a band shape at a position slightly deviated toward the exhaust port side from 72f. Therefore, the wire mesh 1 inside the half shell 71
2 and the damper mesh 13, by inserting one of the halves, for example, a half ring 241, and storing the catalyst carrier 6, both meshes 1
The cylindrical part 241 of the half ring 241 with the elasticity of 2, 13
a tightly elastically press-fits to the lower half of the inlet-side end of the catalyst carrier 6, and its lip portion 241b bends to elastically press-fit to the protrusion 26 of the half shell 71. Next, the other half ring 242 is placed on the inlet side end of the catalyst carrier 6 assembled in this way.
When stacked and covered with the other half shell 72, the pair of half rings 241, 242 are joined into a closed ellipse, and the cylindrical portion 242a of the half ring 242 is similarly placed on the inlet side of the catalyst carrier 6. The upper half of the end portion is elastically crimped, and the lip portion 242b is crimped to the protrusion 27 of the half shell 72. Furthermore, at this time, the peak portion 25 of the half ring 241 fits into the V-shaped gap inside the joint of the half shells 71 and 72 that are joined together like a shell, and the half shell 71 and the half shell 71 and
72. In this way, the seal ring 24
Since it is provided by elastic pressure bonding to the entire outer periphery of the catalyst carrier 6 and the entire inner periphery of the half shells 71 and 72, which are integrated like a shell in a half-split structure, the inlet side of the catalyst carrier 6 and the half shells 71, 72 is firmly secured. Note that the seal ring 24 mentioned above is split horizontally in the same way as the half-split shells 71 and 72;
It can also be divided vertically. In this way, the catalyst carrier 6 is 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.
In addition, the wire mesh 12 and the damper meshes 13 and 14, the seal ring 24 and the inlet side of the catalyst carrier 6, and the half shells 71 and 72 are also tightly pressed together to ensure gas sealing. By inserting and joining the pipe ends of the upstream exhaust pipes 2 and 3 into the inlet ports 10 and 11 of the catalyst shell 7, respectively, and joining the downstream exhaust pipe 4 to the outlet port 15, the catalytic converter 5 is assembled to the collecting part of the exhaust system. 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 extend almost all around the circumference except for the above-mentioned three fixing parts, and the upper and lower mating parts thereof are spaced apart from each other with a predetermined opposing interval, 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 15
A temperature sensor 23 is attached near the. Since the catalytic converter device according to the embodiment of the present invention has the above-described configuration, the exhaust gas discharged from the left and right cylinders of the engine body 1 is alternately passed through the two exhaust pipes 2 and 3 at predetermined exhaust timing. Then, it enters the catalyst shell 7 through the inlet ports 10 and 11 of the catalytic converter 5. At this time, the inlet ports 10 and 11 are opened diagonally outward relative to the axial center line of the shell 7 so that their axial center lines cross 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 rectification chamber 9 inside the inlet, and collides obliquely with the inlet side end face of the catalyst carrier 6 housed inside. As a result, the gas flow becomes turbulent inside the gas rectification chamber 9, its flow velocity decreases, and the passage time of the gas passing through the catalyst carrier 6 increases. Furthermore, on the outlet side, the outlet port 15 is open to one side with respect to the center line in the axial direction of the body of the shell 7, so that the passage of gas is also suppressed, and the catalyst carrier as a whole is 6 is ensured for a long time. On the other hand, the inlet side of the catalyst carrier 6 and the half shell 71,
Since the seal ring 24 is elastically pressed between the catalyst shells 72 and 72 to ensure gas sealing, all of the exhaust gas flowing into the catalyst shell 7 passes through the catalyst carrier 6. Mixing etc. in the gas rectification chamber 9 are performed smoothly without loss.
The seal ring 24 is a half ring 2 divided into two parts.
Consisting of 41,242 half-rings 24
1,242 are independently and elastically crimped onto the catalyst carrier 6, thereby absorbing variations in the dimensions of the catalyst carrier 6. Variations in the dimensions of the half shells 71, 72 are absorbed by each half ring 241, 242. It is similarly absorbed by the elastic deflection of the lip portions 241b and 242b.

【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
A seal ring 24 is added between the catalyst carrier 6 and the half shells 71 and 72, and this ring is elastically pressed against the inner surfaces of these shells, so that variations in the dimensions of the catalyst carrier 6 and the half shells 71 and 72 can be absorbed. Because
Good gas sealing performance can always be ensured at the inlet side end of the catalyst carrier 6. Furthermore, the seal ring 24 is divided into two, and the lip portion 241 of the pair of half rings 241 and 242 is split into two.
Since the outwardly protruding peaks 25 formed on the shells b and 242b are fitted and crimped into the gap formed inside the joint of the half shells 71 and 72, exhaust gas is prevented from flowing through this gap. Leakage is prevented and the gas sealing effect is further improved to almost complete.
3 is not exposed to exhaust gas, prevents early deterioration, and can extend the life of the catalytic converter. As described above, since the seal ring 24 that significantly improves the gas sealing effect is formed by simply joining the half rings 241 and 242, the bellows-shaped annular body of the prior art example described above is Its structure is extremely simple and therefore economical. 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 is expanded compared to the case where only a damper mesh is provided on the inlet end face. It becomes wider.

[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. A perspective view showing an exploded half shell of the catalytic converter device, FIG. 5 is a sectional view taken along the - line in FIG. 2, and FIG. 6 is a - in FIG. 2.
7 is an enlarged sectional view of section A in FIG. 2, FIG. 8 is a perspective view of a seal ring, and FIG. 9 is a sectional view of a half-shell joint. 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, 71, 72... Half shell, 24...
... Seal ring, 241, 242 ... Half ring, 241a, 242a ... Cylinder part, 241b, 2
42b...Rip part, 25...Mountain part, 26, 27
……protrusion.

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 midway and communicated with a muffler, a catalytic converter is disposed at the location of the collection part, and the catalyst shell of the catalytic converter is Consisting of a pair of half shells,
By working together and joining the pair of half-shells to accommodate and support the catalyst carrier inside, a plurality of gas inlet ports are formed on the joint surface of one end, and an outlet port is formed on the joint surface of the other end. 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, and the inlet end of the catalyst carrier and the exhaust pipe are connected to the outlet port. A seal ring is interposed between the half shell and the seal ring, which joins the pair of half rings at a position away from the joining line of the outer half shell. The cylindrical part of the half ring is fitted to the inlet side end of the catalyst carrier, and a wire mesh with damper meshes for exhaust gas sealing attached to both ends is wrapped around the outer periphery of the cylindrical part and the outer periphery of the catalyst carrier. The catalyst carrier is elastically supported within the catalyst shell by elastic compression by the half shell, and almost the entire circumference of the tip of the lip on the exhaust port side of the half ring is elastically compressed onto the inner surface of the half shell. A catalyst for purifying automobile exhaust gas, characterized in that a peak portion formed on the lip portion so as to protrude outward is fitted and pressed into a gap formed inside the half-shell joint portion. converter device.