JP2000018029A - Manifold converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent cracking and the like of a welding part on a shell caused by thermal deformation of a cap. SOLUTION: A manifold converter is provided with a metallic shell, a catalyst carrier housed in the shell, a pair of metallic caps 29, 31 formed in a nearly cross sectional L-shape by annular flange parts 29a, 31a and cylindrical parts 29b, 31b, and a cushioning material 33 interposed between at least one of caps 29, 31 and an end surface 27a of the catalyst carrier, and the catalyst carrier is held between a pair of caps 29, 31 welded on the shell 25 through the cushioning material 33. A thermal deformation absorbing part for absorbing a thermal deformation difference between the cap 29 and the shell 25 is arranged between the cap 29 and the welding part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a manifold converter mounted on a vehicle exhaust system.

[0002]

2. Description of the Related Art Conventionally, a vehicle exhaust system has been equipped with CO in exhaust gas.
Although a catalytic converter for purifying harmful components such as the like is mounted under the floor of a vehicle, such a catalytic converter has recently been replaced with an exhaust gas outlet of an exhaust manifold directly as disclosed in Japanese Utility Model Laid-Open No. 6-80815. A so-called manifold converter to be mounted is mounted on many vehicles.

FIG. 7 shows a manifold converter disclosed in Japanese Utility Model Laid-Open Publication No. 6-80815. The manifold converter 1 is mounted substantially vertically on an exhaust gas outlet of an exhaust manifold 3, and a pair of half-shells 5.
a, 5b, inside the metal shell 5
A ceramic catalyst carrier 11 having an elliptical cross section is accommodated via a pair of upper and lower metal caps 7 and a metal mesh-shaped cushioning material 9 which are plug-welded to the ceramic carrier.

As shown in FIG. 8, the cap 7 has an annular flange portion 7a facing the end face of the catalyst carrier 11, a cylindrical portion 7b vertically suspended from the outer peripheral end of the annular flange portion 7a,
A C-shaped ring member formed by an inner cylindrical portion 7c vertically provided from an inner peripheral end of the annular flange portion 7a;
The (in the figure, P ₁ ~P _{4) 4} positions of the cylindrical portion 7b are stoppered welded to the shell 5, in the corresponding portion of the shell 5 for fixing the cap 7, provided with holes for plug welding (not shown) Have been.

[0005] The catalyst carrier 11 is held at a constant pressure via a buffer material 9 between a pair of upper and lower caps 7 plug-welded to the shell 5. Also, four pipes 3a, 3 of the exhaust manifold 3 are provided in the upper opening of the shell 5.
A flat bowl-shaped upstream diffuser 13 in which discharge ends b, 3c and 3d are gathered and connected is welded, and a downstream diffuser 17 having an exhaust gas outlet 15 formed in a lower opening of the shell 5. Is exhausted, the exhaust gas flowing from the exhaust manifold 3 is purified by the catalyst carrier 11, and then guided from the exhaust gas outlet 15 to the muffler on the downstream side.

[0007] In addition, in FIG. 7, reference numeral 19 denotes a supporter (holding member) made of a woven cloth-shaped metal wire wound around the outer periphery of the catalyst carrier 11, and 21 denotes a thermally expandable inorganic material mat (trade name: Intramat ), The bypass of the exhaust gas is prevented by the thermally expandable inorganic material mat 21.

[0007]

As described above, conventionally, the catalyst carrier 11 is held in the shell 5 by the pair of upper and lower caps 7 and the cushioning material 9 which are plug-welded to the shell 5. Is mounted immediately below the engine, so that high-temperature exhaust gas flows into the manifold converter 1.

The shell 5 and the cap 7 repeat expansion and contraction, respectively, due to the inflow of exhaust gas and the stoppage of the engine when the engine is driven. A supporter 19 and a heat-expandable inorganic material mat are provided between the shell 5 and the catalyst carrier 11. 21 is interposed, the cap 7 holds the catalyst carrier 11 which becomes high in temperature due to the catalytic combustion.
Is directly exposed to high-temperature exhaust gas, the temperature difference between the cap 7 and the shell 5 is large, and a difference in thermal expansion occurs between the two.

For this reason, cracks occur in the plug welding portion of the shell 5 due to long-term use, causing gas leakage,
It has been pointed out that the cap 7 itself may be damaged by the large thermal deformation of the cap 7, or that the upstream end of the catalyst carrier 11 may be scraped by the damaged cap 7. The present invention has been devised in view of such circumstances, and an object of the present invention is to provide a manifold converter that prevents cracks in a welded portion of a shell due to thermal deformation of a cap, damage to a cap itself, and the like.

[0010]

Means for Solving the Problems In order to achieve the above object, the invention according to claim 1 comprises a metal shell, a catalyst carrier housed in the shell, and an annular shape opposed to an end face of the catalyst carrier. A pair of metal caps formed in a substantially L-shaped cross section by a flange portion and a tubular portion vertically provided from an outer peripheral end of the annular flange portion, and between at least one cap and an end face of the catalyst carrier; In a manifold converter having an interposed buffer material and holding a catalyst carrier via a buffer material between a pair of caps welded to the shell, the cap absorbs a difference in thermal deformation with the shell. The heat deformation absorbing portion is provided between the welded portions.

According to a second aspect of the present invention, there is provided a metal shell, a catalyst carrier housed in the shell, an annular flange portion facing an end face of the catalyst carrier, and a vertically extending outer peripheral end of the annular flange portion. One metal cap formed in a substantially L-shaped cross section with the provided cylindrical portion, a carrier holding portion formed on the downstream side of the shell, and between the cap and the end face of the catalyst carrier, or A cushioning material interposed at least between the end face of the catalyst carrier and the carrier holding portion, the catalyst being interposed between the cap and the carrier holding portion welded on the upstream side of the shell via the cushioning material. In the manifold converter holding the carrier, a heat deformation absorbing portion for absorbing a heat deformation difference from a shell is provided between the welded portions in the cap.

According to a third aspect of the present invention, in the manifold converter according to the first or second aspect, the thermal deformation absorbing portion is provided with a notch in the annular flange portion or the cylindrical portion. The invention according to claim 4 is characterized in that:
Alternatively, in the manifold converter according to the second aspect, the thermal deformation absorbing portion includes a bead-shaped deformation allowance protruding from the annular flange portion and a notch provided in the cylindrical portion corresponding to the deformation allowance. It is characterized by:

The invention according to claim 5 is the invention according to claim 1.
Alternatively, in the manifold converter according to the second aspect, the cap is divided into a plurality of portions between the welded portions, and has a gap serving as a thermal deformation absorbing portion between the ends of the adjacent divided caps.

(Operation) According to the manifold converter according to the first and second aspects, the shell and the cap repeatedly expand and contract due to the inflow of exhaust gas and the stop of the engine when the engine is driven. The thermal deformation absorbing part provided in the above absorbs the thermal deformation difference from the shell.

According to the third aspect of the present invention, the annular flange portion or the cylindrical portion corresponding to the notch is thermally deformed to absorb a thermal deformation difference from the shell. The deformation allowance is positively thermally deformed to absorb the difference in thermal deformation with the shell. According to the fifth aspect of the invention, the end portions of the divided caps constituting the cap are thermally deformed, respectively, to absorb a difference in thermal deformation with the shell.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an embodiment of the manifold converter according to claims 1 and 3, and FIG.
Similarly to the manifold converter 1 shown in FIG. 1, the manifold converter 23 according to the present embodiment is also mounted substantially vertically to an exhaust gas outlet of an exhaust manifold (not shown).

A pair of half-shells 25a, 25
A ceramic catalyst carrier 27 having an elliptical cross section is accommodated in a metal shell 25 made of b through a pair of upper and lower C-shaped metal caps 29 and 31 and a metal mesh-shaped cushioning material 33. The catalyst carrier 27 is provided with a cushioning material 33 between a pair of caps 29 and 31 plug-welded to the shell 25.
Is maintained at a constant pressure.

Although not shown, a plug welding hole is provided at a position corresponding to the shell 25 for fixing the caps 29 and 31. A supporter 35 made of a woven fabric thin metal wire and a thermally expandable inorganic material mat 37 are wound around the outer periphery of the catalyst carrier 27, and the upstream and downstream outer periphery of the catalyst carrier 27 are A metal mesh-like buffer material 39 is wound, and the supporter 35 and the buffer material 39 elastically hold the catalyst carrier 27 in the shell 25. Then, the cylindrical portions 2 of the caps 29 and 31
The tips of 9a and 31a are in contact.

A bowl-shaped upstream diffuser 41 for collecting and connecting exhaust manifold pipes is welded to an upper opening of the shell 25, and an exhaust gas outlet is formed at a lower opening of the shell 25. The downstream diffuser 43 is welded, and the exhaust gas flowing from the exhaust manifold is purified by the catalyst carrier 27 and guided from the exhaust gas outlet to the muffler on the downstream side.

As described above, the manifold converter 23 according to this embodiment also has a pair of upper and lower caps 29, 31 in which the catalyst carrier 27 is plug-welded to the shell 25, as in the conventional case.
In the present embodiment, the temperature difference between the shell 25 and the cap 29 mounted on the upstream side of the catalyst carrier 33 is still large. A differential expansion occurs.

Therefore, in the present embodiment, the crack in the plug welding portion of the shell 25 due to the thermal deformation of the cap 29 or the cap 2
In order to prevent breakage of 9 itself, etc., it has the following features in addition to the same configuration as the conventional one as described above. FIG. 2 shows a cap 29 mounted on the upstream side of the catalyst carrier 27. The cap 29 also has an annular flange portion 29 a facing the end surface 27 a of the catalyst carrier 27, and a tube vertically provided from the outer peripheral end of the annular flange portion 29 a. Shape part 29b and annular flange part 29a
And an inner cylindrical portion 29c vertically provided from the inner peripheral end of the inner cylindrical portion 29c. The inner cylindrical portion 29c is shorter than the cylindrical portion 29b.

The cap 29 is plug-welded to the shell 25 at four locations (P _{1 to} P _{4 in the} figure) of the cylindrical portion 29b. Thus, as shown in FIG.
b, a notch 45 is provided between each of the plug welds P _{1 to} P ₄ , and the inner cylindrical portion 2 corresponding to each of the notches 45 is provided.
9c is also provided with a notch 46. By providing the notches 45 and 46 in the cylindrical portion 29b and the inner cylindrical portion 29c in opposition to each other, the cap 2 exposed to high-temperature exhaust gas is provided.
9 is an annular flange portion 2 corresponding to each of the notches 45 and 46.
9a (areas A, B, and C in the figure) are most easily thermally deformed. As a result, the respective portions of the annular flange portion 29a are
Each of them functions as a thermal deformation absorbing portion for absorbing a thermal deformation difference from the shell 25.

As shown in FIG. 1, the cap 31 mounted on the downstream side of the catalyst carrier 27 also
The catalyst carrier 27 is formed by an annular flange portion 31a opposed to the inner surface 7a, and a cylindrical portion 31b and an inner cylindrical portion 31c which are respectively suspended from an outer peripheral end and an inner peripheral end of the annular flange portion 31a. The temperature of the downstream side is lower than that of the upstream side, and the difference in thermal expansion between the cap 31 and the shell 25 does not matter so much. Therefore, the cap 31 has the same shape as the conventional cap 7 shown in FIG.

In this embodiment, the shell 25 and the cap 29 are repeatedly expanded and contracted by the inflow of exhaust gas and the stoppage of the engine when the engine is driven. Weld P
Site of the annular flange portion 29a corresponding to the notches 45, 46 provided between ₁ to P ₄ is thermally deformed to absorb the thermal deformation difference between the shell 25.

Therefore, according to the present embodiment, even if the shell 25 and the cap 29 repeatedly expand and contract due to the inflow of exhaust gas and the stop of the engine, stress is applied to the plug welding portion of the shell 25 for plug welding the cap 29. As a result, cracks do not occur in the plug welding portion of the shell 25 due to long-term use, and the cap 29 itself is damaged by thermal deformation of the cap 29,
The upstream end of the catalyst carrier 27 is no longer scraped by the damaged cap 29.

FIG. 3 shows an upstream side cap used in the manifold converter according to the first and fourth embodiments of the present invention. As shown in FIG.
Also, an annular flange portion 47a opposed to the end surface 27a of the catalyst carrier 27, a cylindrical portion 47b suspended from an outer peripheral end of the annular flange portion 47a, and a cylindrical portion suspended from an inner peripheral end of the annular flange portion 47a. Jo portion is formed in the 47c, (in the figure, P ₁ ~P _{4) 4} positions of the cylindrical portion 47b is adapted to be plug welded to the shell 25.

Each of the plug welding portions P is provided on the cylindrical portion 47b.
₁ with each notch 49 between to P ₄ are provided notches in the inner cylindrical portion 47c in correspondence with the respective notches 49 5
0 is formed. Each of the annular flange portions 47a corresponding to the notches 49, 50 is provided with a bead-shaped deformation allowance 51 projecting upward, and a synergistic effect between the respective deformation allowances 51 and the notches 49, 50 is provided. By operation, these function as a thermal deformation absorbing portion that absorbs a thermal deformation difference from the shell 25.

Since other configurations are the same as those of the above-described embodiment, the same components are denoted by the same reference numerals and description thereof will be omitted. The cap 47 according to the present embodiment is configured as described above. The catalyst carrier 27 includes a pair of upper and lower caps 31 and 47 plug-welded to the shell 25 and the cushioning material 33.
Is held in the shell 25.

When the exhaust gas flows in by driving the engine and the engine is stopped, the shell 25 and the cap 47 are moved.
Repeatedly expands and contracts. However, as described above, the annular flange portion 47a is provided with the deformation allowance 51 corresponding to the notches 49 and 50 provided in the cylindrical portion 47b and the inner cylindrical portion 47c. The deformation allowance 51 is positively thermally deformed, and absorbs the difference in thermal deformation with the shell 25.

Therefore, according to the present embodiment, cracks are not generated in the plug welding portion of the shell 25 due to long-term use, and the cap 29 itself is damaged by thermal deformation of the cap 29, and the catalyst carrier is not damaged. In this embodiment, the upstream end of 27 is not scraped off by the damaged cap 29, and in the present embodiment, the annular flange 47a is positively provided with the deformation allowance 51 which is easily deformed by heat. It is possible to achieve the intended purpose more reliably than in the case of the twenty-ninth embodiment.

FIG. 4 shows an upstream side cap used in the manifold converter according to the first and fifth embodiments. As shown in FIG.
Is composed of two divided caps 53-1 and 53-2. Each of the divided caps 53-1 and 53-2 has an annular flange portion 53-1a and an annular flange 53-1a facing the end surface 27a of the catalyst carrier 27, respectively.
53-2a, cylindrical portions 53-1b and 53-2b vertically suspended from the outer peripheral ends of the respective annular flange portions 53-1a and 53-2a, and inner peripheral ends of the annular flange portions 53-1a and 53-2a. And inner cylindrical portions 53-1c and 53-2c which are vertically provided from the inner side.

Then, as shown in FIG.
In this embodiment, -1 and 53-2 are plug-welded to the shell 25 at one location (P ₁ and P _{2 in the} figure) of the cylindrical portions 53-1b and 53-2b, respectively. Are divided caps 53-1,
One part of 53-2 is plug-welded to the shell 25, and both ends 53a-1, 53a of the adjacent divided caps 53-1, 53-2.
-2, a gap is provided as a thermal deformation absorbing portion.

According to the present embodiment, the shell 25 and the cap 53 repeat expansion and contraction due to the inflow of exhaust gas and the stop of the engine when driven by the engine, but the divided caps 53-1 and 53 constituting the cap 53 are repeated. -2 are thermally deformed at both ends 53a-1 and 53a-2, respectively, to absorb the difference in thermal deformation with the shell 25. Therefore, according to the present embodiment, it is possible to achieve the intended purpose, similarly to the above-described embodiments.

The cap 29 shown in FIG.
Although the notches 45 and 46 are provided on the 9b and the inner cylindrical portion 29c, a notch may be provided on the annular flange portion 29a side. In the embodiment shown in FIG. 4, the cap 53 is divided into two parts. However, for example, when the cap is to be plug-welded to the shell 25 at three places, the cap is divided into three portions between the plug weld portions, and a gap serving as a thermal deformation absorbing portion is provided between the ends of the adjacent split caps. I just need.

FIGS. 5 and 6 show one embodiment of the manifold converter according to claims 2 and 3. In each of the embodiments shown in FIGS. 1 to 4, the catalyst carrier is placed inside the shell by using a pair of upper and lower caps. Instead of such a manifold converter, a carrier holding portion is conventionally formed downstream of the shell, and the catalyst carrier is buffered by the cap and the cap which is plug-welded upstream of the shell. There is also known a manifold converter which is held in a shell through a shell.

However, even in such a manifold converter, a thermal expansion difference occurs between the shell and the cap mounted on the upstream side of the catalyst carrier. Therefore, the present embodiment has the following features in order to prevent cracks at the plug welding portion of the shell due to thermal deformation of the cap, damage to the cap itself, and the like.

In FIG. 5, 55 denotes a pair of half-shells 5.
5a and 55b made of a metal.
On the downstream side of 5, a carrier holding portion 57 formed of a step portion whose diameter is reduced inward is formed. Then, the carrier holding unit 5
7 is provided with a metal mesh-shaped cushioning member 58 for holding the downstream end surface 27b of the catalyst carrier 27, and the carrier holding portion 57
And one metal cap 59 plug-welded to the upstream side of the shell 55, and the catalyst carrier 27 via the cushioning material 58.
Is maintained at a constant pressure.

As in the above embodiments, a supporter 35 made of a woven metal thin wire and a thermally expandable inorganic material mat 37 are wound around the outer periphery of the catalyst carrier 27. A cushioning material 39 is wound between the upstream side surface and the cap 59, and the catalyst carrier 27 is elastically held by the shell 55 by the supporter 35 and the cushioning material 39.

FIG. 6 shows a cap 59 mounted on the upstream side of the catalyst carrier 27. The cap 59 has an annular flange portion 59a facing the end surface 27a of the catalyst carrier 27, and is vertically provided from the outer peripheral end of the annular flange portion 59a. Tubular part 59b
And formed. Then, the cap 59, (in the figure, P ₁ ~P _{4) 4} positions of the cylindrical portion 59b is adapted to be plug welded to the upstream side of the shell 55 at.

[0040] In Thus, the tubular portion 59b as shown, and each notch 61 is provided between the plug weld P ₁ to P _4, notches to such a cylindrical portion 59b By providing the 61, the cap 59 exposed to the high-temperature exhaust gas is provided with an annular flange portion 59a (A, A,
B and C regions) are most easily thermally deformed. As a result, the respective portions of the annular flange portion 59a each function as a thermal deformation absorbing portion that absorbs a thermal deformation difference from the shell 55. .

In this embodiment, the shell 55 and the cap 59 are repeatedly expanded and contracted by the inflow of exhaust gas and the stop of the engine when the engine is driven. Weld P
Site of the annular flange portion 59a corresponding to the notches 61 provided between ₁ to P ₄ is thermally deformed to absorb the thermal deformation difference between the shell 55.

Therefore, according to the present embodiment, similarly to the embodiment shown in FIG. 1, even if the shell 55 and the cap 59 repeatedly expand and contract due to the inflow of exhaust gas and the stop of the engine, the shell 55 for plug welding the cap 59 is provided. No stress is applied to the plug welding portion of the shell 55. As a result, cracks do not occur in the plug welding portion of the shell 55 due to long-term use, and the cap 59 itself is damaged by thermal deformation of the cap 59. Also, the upstream end of the catalyst carrier 27 is not scraped by the damaged cap 59.

[0043]

As described above, according to the manifold converter of the present invention, even if the shell and the cap repeatedly expand and contract due to the inflow of exhaust gas and the stoppage of the engine, the heat deformation absorbing portion provided on the cap is provided. Since the difference in thermal deformation from the shell is absorbed, stress is not applied to the welded portion of the shell for welding the cap, and as a result, cracks are not generated in the welded portion of the shell due to long-term use, and In addition, the cap itself is not damaged by the thermal deformation of the cap, and the upstream end of the catalyst carrier is not scraped by the damaged cap.

[Brief description of the drawings]

FIG. 1 is a sectional view of a manifold converter according to an embodiment of the present invention.

FIG. 2 is a perspective view of an upstream side cap used in the manifold converter shown in FIG.

FIG. 3 is a perspective view of an upstream side cap used in the manifold converter according to the first and fourth embodiments;

FIG. 4 is a perspective view of an upstream cap used in the manifold converter according to the first and fifth embodiments;

FIG. 5 is a sectional view of a manifold converter according to an embodiment of the present invention.

6 is a perspective view of a cap used in the manifold converter shown in FIG.

FIG. 7 is a partially cutaway front view of a conventional manifold converter.

FIG. 8 is a perspective view of a conventional cap.

[Explanation of symbols]

23 Manifold converter 25, 55 Shell 27 Catalyst carrier 29, 31, 47, 53, 59 Cap 29a, 47a, 53-1a, 53-2a, 59a Annular flange portion 29b, 47b, 53-1b, 53-2b, 59b Tube Shaped portion 29c, 47c, 53-1c, 53-2c Inner cylindrical portion 33, 58 Buffer material 45, 46, 49, 50, 61 Notch 51 Deformation allowance 57 Carrier holding portion

Claims (5)

[Claims] 1. A metal shell (25), and a catalyst carrier (27) housed in the shell (25).
And an annular flange portion (29a, 31a, 47a, 53-1a, 53-2) facing the end surface (27a) of the catalyst carrier (27).
a) and the annular flange portions (29a, 31a, 47a,
53-1a, 53-2a) and a pair of metal parts formed in a substantially L-shaped cross section with cylindrical portions (29b, 31b, 47b, 53-1b, 53-2b) vertically provided from the outer peripheral end. Cap (2
9, 31, 47, 53) and at least one cap (29, 31, 47, 53)
And a cushioning material (33) interposed between the catalyst and the end face of the catalyst carrier (27), and a pair of caps (29, 3) welded to the shell (25).
In the manifold converter holding the catalyst carrier (27) via the buffer material (33) between the caps (29, 31, 47, 53) and the shell (25), A manifold converter, wherein a heat deformation absorbing portion for absorbing a heat deformation difference is provided between welding portions. 2. A metal shell (55), and a catalyst carrier (27) housed in the shell (55).
An annular flange portion (59a) facing the end surface (27a) of the catalyst carrier (27) and a tubular portion (59b) vertically suspended from an outer peripheral end of the annular flange portion (59a); One metal cap (59) formed on the carrier holding portion (5) formed on the downstream side of the shell (55).
7), between the cap (59) and the end face of the catalyst carrier (27), or between the end face of the catalyst carrier (27) and the carrier holding portion (57).
And a cushioning material (58) interposed between at least one of the cap (5) and the cap (5) welded to the upstream side of the shell (55).
In the manifold converter in which the catalyst carrier (27) is held between the carrier (9) and the carrier holding part (57) via the buffer material (58), the heat from the shell (55) is applied to the cap (59). A manifold converter, wherein a heat deformation absorbing portion for absorbing a deformation difference is provided between welding portions. 3. The thermal deformation absorbing portion includes an annular flange portion (29).
The manifold converter according to claim 1 or 2, wherein a cutout (45) is provided in a) or the cylindrical portion (29b). 4. The thermal deformation absorbing portion includes an annular flange portion (47).
A bead-shaped deformation allowance (51) protruding from (a) and a notch (49) provided in the cylindrical portion (47b) corresponding to the deformation allowance (51). The manifold converter according to claim 1 or 2. 5. The cap (53) is divided into a plurality of portions between the welded portions, and is thermally deformed between end portions (53a-1, 53a-2) of adjacent divided caps (53-1, 53-2). The manifold converter according to claim 1, further comprising a gap serving as an absorption section.