JP4624878B2 - Catalytic converter case and manufacturing method thereof - Google Patents

Description

  The present invention relates to a catalytic converter case and a manufacturing method thereof.

Conventionally, harmful components of exhaust gas discharged from automobile engines have been purified by a catalytic converter disposed downstream of the exhaust manifold. The catalytic converter has a catalyst main body for purifying exhaust gas in a catalytic converter case and is disposed in an exhaust passage. For example, as disclosed in Patent Document 1, the catalytic converter case has two metal press-formed products when the inner diameters of the inlet and the outlet are different and the directions of the inlet and the outlet are different. Are formed into a cylindrical shape, and the butted portions are welded to form a funnel shape.
JP-A-9-273417 (paragraphs 0023 to 0027, FIGS. 6 and 7)

However, in the catalytic converter case described in Patent Document 1, the funnel portion is formed by bending two metal plate materials (an upper half and a lower half) into a curved press-molded product, and then bent. The end portions on both sides in the direction are respectively welded in a cylindrical shape. When such a catalytic converter case is welded, the number of places to be joined increases according to the number of metal plate materials, and the number of places to be welded increases. Therefore, the welding operation time and cost increase, and the strength decreases. There was a problem.
In addition, the funnel part of the catalytic converter case is welded after the work divided into two parts, the upper half and the lower half, is aligned with each other and fixed so that the shape does not collapse. ing. During this welding operation, the upper half and the lower half must be held so that they do not deviate from each other, so that there is a problem that workability during assembly is poor.

  Therefore, the present invention has been made to solve the problems of the prior art, and an object of the present invention is to provide a catalytic converter case that can shorten welding work time and improve strength, and a method for manufacturing the same. It is to provide.

In order to solve the above-mentioned problem, the catalytic converter case according to claim 1 is a catalytic converter case that houses a catalyst body that purifies exhaust gas of an internal combustion engine, and has a cylindrical shape that houses the catalyst body. A case main body portion, and a funnel portion connected to the case main body portion, wherein the funnel portion has a small diameter portion formed on one opening end side and a diameter larger than the small diameter portion on the other opening end side. the large diameter portion is formed in a larger diameter in a funnel shape, with the pipe is formed in a curved shape, is formed by bending a single metal plate into a cylindrical shape, opposite ends of the circumferential direction Projecting outward in a state of being in contact with each other, formed in an arcuate flange shape when viewed from the front, and the end of the flange shape is formed on the inner peripheral surface side formed in the curved shape. and characterized in that it is welded and joined.

  According to the first aspect of the present invention, the catalytic converter case is formed such that the funnel portion is formed of a single metal plate in a cylindrical shape so that the funnel portion is joined to each other when the funnel portion is formed in a cylindrical shape. Since there are few places to weld, strength can be improved. Further, since the funnel portion is made of a single metal plate, the number of locations to be held is small when welding the joint location, and therefore the operation of fixing and holding the funnel portion is facilitated. When welding the joining location, the location to be welded is one location on both ends in the circumferential direction. As a result, the funnel portion can reduce the manufacturing time and cost of the catalytic converter case because the welding operation time is reduced by the amount of welding points (joining points). The funnel portion formed in this way can be piped in correspondence with the surrounding layout where the conduit is formed in a curved shape.

The catalytic converter case according to claim 2 is the catalytic converter case according to claim 1, wherein the funnel portion is bent into a cylindrical shape by sheet metal pressing , and ends on both sides in the circumferential direction. Is arranged at a position where the distance from the periphery of the large diameter portion to the periphery of the small diameter portion is the shortest distance of the conduit .

  According to this invention of Claim 2, the edge part of the both sides of the circumferential direction of a funnel part is formed in the internal peripheral surface side formed in the curve shape, and the position used as the shortest distance of the pipe line direction in the funnel part Since the length of the welding location is shortened, the welding operation time is shortened, and the manufacturing can be performed in a short time. As a result, the manufacturing time and the cost of welding rods are reduced, so that the manufacturing cost of the catalytic converter case can be reduced.

The method for producing a catalytic converter case according to claim 3 is the method for producing a catalytic converter case according to claim 1 or 2, wherein the method for producing the catalytic converter case according to claim 1 or 2 is used. The method of manufacturing a catalytic converter case according to claim 1 or 2, wherein the funnel portion extends from the large-diameter portion to the small-diameter portion on one workpiece made of the metal plate. drawing process and ablation step of cutting the excess portion of the workpiece cut processed to the direction of the axial line of the large diameter portion of the curved shaped portion formed by deep drawing from the direction of the axial line of the large diameter portion Te When the bending step Ru bent into a substantially U-shape facing the conduit direction by bending in a direction perpendicular to the workpiece to the axial line of the large diameter portion, the workpiece to the axial line of the large diameter portion processed and bent from a direction perpendicular A combined forming the shape of the final the funnel portion formed in Jo is matched on both sides of the end portions in the circumferential direction, and the welding process to complete the funnel portion by welding said end portions, the It is manufactured by the process of including.

  According to the third aspect of the present invention, a single workpiece is drawn, cut, and bent to form a cylinder, the ends on both sides in the circumferential direction are butted together, and the ends on both sides By welding the portions, the number of locations where the end portions on both sides are welded is small. As a result, the welding operation time is shortened, and the strength of the funnel portion is improved by the amount of welding points (joining points). Moreover, the workpiece | work can reduce the contamination (fine dust) which generate | occur | produces in a funnel part by matching the edge parts of the both sides of the circumferential direction formed in the cylinder shape, and welding that edge part.

  According to the catalytic converter case and the manufacturing method thereof of the present invention, since the funnel portion is formed from a single metal plate, the number of welding points can be reduced, so that the welding operation time is shortened and the strength is improved. be able to.

Next, the best mode for carrying out the invention (hereinafter referred to as “embodiment”) will be described with reference to FIGS.
Hereinafter, as an example of an embodiment of the present invention, a case where a funnel portion is provided on the inlet side (upstream side) of the case main body portion of the catalytic converter will be described as an example.
FIG. 1 is an enlarged front view showing a catalytic converter case according to an embodiment of the present invention.

<Composition of catalytic converter>
As shown in FIG. 1, the catalytic converter C reduces CO, HC, NO _{x and the} like contained in the exhaust gas of an engine (internal combustion engine) using gasoline, light oil or the like as fuel to a predetermined level by the catalyst body 4. Device. The catalytic converter C purifies the exhaust gas sent from the engine via the manifold (not shown) and the exhaust pipe 5 by passing through the catalyst body 4 and is contained in the exhaust gas. After removing harmful components, it is finally released into the atmosphere. The catalytic converter C includes the catalyst main body 4, a case main body portion 2 in which the catalyst main body 4 is provided, and a funnel portion 3 provided at an open end 2 a of the case main body portion 2.

<Composition of catalyst body>
The catalyst body 4 purifies exhaust gas from an internal combustion engine. The catalyst body 4 is composed of, for example, a monolith type three-way catalytic converter, and is installed in the case body 2 of the catalyst converter case 1 via a mat 7. The catalyst main body 4 may be other as long as it has an exhaust gas detoxifying effect, and may be one or plural, and is not particularly limited.

<Composition of mat>
The mat 7 is a member that covers and protects the outer peripheral portion of the catalyst body 4 so as to be wound, and absorbs vibration from the engine and the like so that the vibration is not transmitted to the catalyst body 4. The case body 2 is mounted so as not to be displaced. The mat 7 is formed of a heat insulating material to eliminate the occurrence of distortion and the like when the metal portion of the catalyst body 4 repeatedly contracts and expands due to heat from the engine, and suppresses heat dissipation of the catalyst body 4. It is arranged so that it can also be done.

<Composition of catalytic converter case>
The catalytic converter case 1 is a cylindrical (tubular) case body for housing the catalyst main body 4, and includes a case main body portion 2 and a funnel portion 3. In the catalytic converter case 1, for example, an exhaust pipe 5 is connected to the inlet side, and an exhaust pipe 6 is connected to the outlet side, thereby forming an exhaust flow path R through which exhaust gas flows.

<Configuration of the case body>
The case main body 2 is formed of a cylindrical shape that houses the catalyst main body 4, and is formed of a metal material such as stainless steel, steel, or a magnesium alloy. The opening end portions 2 a and 2 b on the inlet side and the outlet side of the case main body portion 2 are formed by reducing the diameter by the thickness of the mat 7.
The opening end 2a on the inlet side is fitted into the large diameter portion 3a of the funnel portion 3 and fixed by welding or brazing.
The outlet end 2b on the outlet side is fitted into an exhaust pipe 6 communicating with a muffler (not shown) installed on the downstream side and fixed by welding or brazing.

<Composition of funnel>
FIG. 2 is an enlarged perspective view showing a funnel portion of the catalytic converter case according to the embodiment of the present invention.
The funnel portion 3 shown in FIG. 1 is a member that is integrally fixed to the opening end portions 2 a and 2 b of the case body portion 2, and is interposed between the case body portion 2 and the exhaust pipe 5, for example. It consists of a funnel-shaped metal cylindrical member. As shown in FIG. 2, the funnel portion 3 has, for example, a small diameter portion 3b formed on the inlet side, a large diameter portion 3a formed on the outlet side, and the large diameter portion 3a and the small diameter portion 3b orthogonal to each other. The large-diameter portion 3a side has a larger diameter than the small-diameter portion 3b, and is formed in an expanded state. As shown in FIG. 1, the funnel portion 3 is formed at a position where the small diameter portion 3 b is displaced from the axial center line OO of the case main body portion 2 (large diameter portion 3 a), and an exhaust flow path (pipe). P is formed in a curved shape, and the opening direction is changed. For this reason, the exhaust flow path P flowing from the exhaust pipe 5 to the case main body 2 through the funnel portion 3 is formed in, for example, an elbow shape or a bend shape which is bent at 90 degrees and changed its direction. The funnel portion 3 is formed by bending a single metal plate into a cylindrical shape by sheet metal pressing, and the end portions 3c and 3d on both sides in the circumferential direction that are bent and formed are joined and welded to be fixed. The funnel portion 3 has the large-diameter portion 3a formed at one end thereof connected to the opening end portion 2a of the case body portion 2 by welding or brazing, and the small-diameter portion 3b formed at the other end portion. It is connected to the exhaust pipe 5 by welding or brazing.

The large diameter portion 3 a is formed to have a diameter that matches the case main body portion 2.
The small diameter portion 3 b is formed to have a diameter that matches the exhaust pipe 5 and opens in a direction orthogonal to the large diameter portion 3 a in accordance with the opening end of the exhaust pipe 5. As a result, the funnel portion 3 is formed in an elbow shape or a bend shape.
Note that the direction in which the small diameter portion 3b is opened may be directed by curving the funnel portion 3 at an appropriate angle in accordance with the layout of equipment installed around the catalytic converter case 1. Moreover, the diameter of the small diameter part 3b should just be formed according to the exhaust pipe 5, and may be the same dimension as the large diameter part 3a.

  The end portions 3c and 3d in the circumferential direction are locations where the funnel portion 3 made of a single metal plate is joined to each other when bent into a cylindrical shape, as shown in FIG. It is formed in an arcuate flange shape when viewed from the front. The end portions 3c and 3d are formed at a position that is the shortest distance in the exhaust flow path P in the funnel portion 3 so that the length of the welded portion (joined portion) A to be welded is shortened. It is formed on the inner peripheral surface side formed in a curved shape.

  The welding location A is, for example, the end portions 3c and 3d formed in the flange shape, and is performed by electrical resistance welding, semi-automatic welding (MIG welding), tungsten electrode welding (TIG welding), or the like. In this way, the end portions 3c and 3d are formed in a flange shape protruding outward from the funnel portion 3, so that the flange portion is electrically resistance welded or sputtered (fly burns) in the funnel portion 3. It is possible to perform welding so that contamination (fine dust) does not occur. In addition, the welding location A shown in FIG. 1 and FIG. 2 has shown an example at the time of carrying out an electrical resistance welding.

<Exhaust pipe configuration>
As shown in FIG. 1, the exhaust pipes 5 and 6 are made of, for example, a stainless steel pipe, a steel pipe, or the like, and are formed in an appropriate shape such as a linear shape or a curved shape on the layout.
The exhaust pipe 5 has an inlet side (upstream side) connected to a manifold (not shown) communicating with an engine (not shown), and an outlet side (downstream side) connected to the funnel portion 3 for welding or brazing. It is fixed by attaching. The diameter of the exhaust pipe 5 is a size that matches the diameter of the small diameter portion 3b to be connected.
The exhaust pipe 6 has an inlet side (upstream side) connected to the open end 2b of the case body 2 and an outlet side (downstream side) connected to a muffler (not shown), and is fixed by welding or brazing, respectively. I am letting. The diameter of the exhaust pipe 6 is a dimension that matches the diameter of the open end 2b of the case body 2 to be connected.

≪Method for manufacturing catalytic converter case≫
Next, the operation of the catalytic converter case and the manufacturing method thereof according to the embodiment of the present invention will be described mainly with reference to FIG. 3 and with reference to FIGS.
FIG. 3 is a process diagram showing a method for manufacturing a catalytic converter case according to an embodiment of the present invention.

  As shown in FIG. 3, when the catalytic converter case 1 is manufactured, first, a drawing step S1 for drawing a metal plate as the workpiece W, a cutting step S2 for cutting off an excess portion of the workpiece W, and a workpiece W Bending step S3, bending the workpiece W into a cylindrical shape, aligning step S4 for matching the circumferential ends 3c, 3d, and circumferential end portions 3c, 3d. After the funnel portion 3 is manufactured by the welding step S5 for welding, the connecting step S6 for joining the funnel portion 3 to the case main body portion 2 is completed.

<Drawing process>
Each step will be described in more detail with reference to FIGS.
4A and 4B are diagrams illustrating a method of manufacturing a catalytic converter case according to an embodiment of the present invention, in which FIG. 4A is a perspective view of a drawn workpiece, and FIG. 4B is a press machine showing a state during a workpiece drawing process. FIG.

First, in the drawing step S1, as shown in FIG. 4B, the workpiece W is held between the upper die 8a of the press 8 and the punch 8b and the holding base 8c, and a lifting device (not shown). ), The upper die 8a is lowered and the workpiece W is pressed against the punch 8b to perform drawing.
In this drawing step S1, the punch 8b presses the workpiece W, and with the upper die 8a, bends one flat workpiece W into a funnel-like shape and performs drawing (press molding). A curved surface portion W1 as shown in FIG. 4A is formed substantially along the center line of the workpiece W (see FIG. 1).

<Resection process>
5A and 5B are diagrams illustrating a method of manufacturing a catalytic converter case according to an embodiment of the present invention, in which FIG. 5A is a perspective view of a cut workpiece, and FIG. 5B is a press machine illustrating a state during a workpiece cutting step. FIG.

In the next cutting step S2, as shown in FIG. 5 (b), the upper die side trim / slit blade 8e and the lower die side die 8d are moved relative to each other by an elevating device (not shown) of the press machine 8 to approach each other. Then, with the upper mold side trim / slit blade 8e, a cutting process (trim process) for cutting the unnecessary unnecessary portion W2 of the workpiece W as scrap as shown in FIG. 5A is performed.
In this excision step S2, it may be excised (blanking or the like) in advance with the expectation of the surplus before drawing, or at any timing after drawing using a die or a laser cutting machine. The timing for performing the cutting step S2 is not particularly limited.

<Bending process>
6A and 6B are diagrams illustrating a method of manufacturing a catalytic converter case according to an embodiment of the present invention, in which FIG. 6A is a perspective view of a workpiece bent into a U-shape, and FIG. 6B is a state during a bending process of the workpiece. It is the principal part schematic of the press machine which shows.

  In the bending step S3, as shown in FIG. 6B, the workpiece W is arranged above the pad 8m, and the punch 8f and the die 8g are moved relative to each other by an elevating device (not shown) of the press machine 8. By bringing them close to each other, the workpiece W is bent into a substantially U shape (press bending). In this bending step S3, the punch 8f raises an elevating device (not shown) to bend the workpiece W in a U shape along the pipe line direction (exhaust flow path P direction). ), The small diameter portion 3b (see FIG. 2) is formed in a U-shape, the large diameter portion 3a (see FIG. 2) is formed in a substantially bowl shape, and the small diameter portion 3b (see FIG. 2) of the workpiece W is formed. The central portion W3 from the reference) to the large diameter portion 3a (see FIG. 2) is formed into a final shape.

  7A and 7B are views showing a method for manufacturing a catalytic converter case according to an embodiment of the present invention, wherein FIG. 7A is a perspective view of a workpiece in which flange portions are formed by bending end portions on both sides, and FIG. It is a principal part schematic of the press machine which shows the state at the time of the alignment process of a workpiece | work.

<Matching process>
In the aligning step S4, as shown in FIG. 7B, a cored bar 8j is inserted inside the workpiece W, the left and right upper molds 8k, 8k of the press machine 8 are brought close to each other, and an end W4 of the workpiece W is obtained. , W4 are matched (edges) to bend the workpiece W into the shape of the cylindrical funnel portion 3 (forming process). In this alignment step S4, the left and right upper molds 8k, 8k are formed so that the mold surfaces are partially formed in substantially the same shape as the final shape of the funnel portion 3, and are moved horizontally to each other by the press 8. By pressing the end portion W4 (see FIG. 6), the end portions W4 on both sides of the workpiece W are bent and matched to form flange-shaped end portions 3c and 3d, and the end portion W4 of the workpiece W is finally finished. In the shape of a typical funnel 3.

<Welding process>
In welding process S5, as shown to Fig.7 (a), the flange-shaped edge parts 3c and 3d of the funnel part 3 are welded. This completes the funnel portion 3. As shown in FIG. 2, the funnel portion 3 formed in this way is formed at a position where the end portions 3 c and 3 d on both sides in the circumferential direction are the shortest distance of the exhaust flow path P in the funnel portion 3. Thus, the length L of the end portions 3c and 3d in the circumferential direction is formed short. As a result, the welding location A is short and can be welded in a short time.

<Connection process>
In connection process S6, as shown in FIG. 1, the large diameter part 3a of the funnel part 3 is fitted to the case main body part 2, and the fitting part is firmly joined by welding or brazing. In this way, the catalytic converter case 1 is completed.

<< Effects of Embodiment >>
The catalytic converter case 1 manufactured as described above has the following effects.
(1) As shown in FIG. 2, the funnel portion 3 can shorten the welding operation time in the welding step S5 in which the end portions 3c and 3d are welded by being able to form the length L of the welded portion A short. The manufacturing cost can be reduced and the contamination can be reduced.
(2) Moreover, since the length L of the welding location A is small and the welding location A is one place, the funnel part 3 can reduce the cost by reducing the welding rod used at the time of arc welding, for example. .
(3) Since the funnel part 3 is formed from one metal plate, the number of places to be joined is as small as one place, so that the quality of the joined part is improved and the strength of the entire funnel part 3 is improved.
(4) As described above, the funnel portion 3 is formed from a single metal plate, and since the welding location A is one location, the yield of the material is improved and the weight at the time of completion is reduced. Therefore, it can contribute to the improvement of the fuel consumption of the vehicle.
(5) In the cutting step S2 shown in FIGS. 5 (a) and 5 (b), the completed funnel portion 3 (see FIG. 7 (a)) is made of one metal plate, so that the upper mold side trim slit Since the material removal by the blade 8e and the lower die 8d is only once, the number of parts is reduced by half and the working efficiency is good.

  It should be noted that the present invention is not limited to the above-described embodiment, and various modifications and changes can be made within the scope of the technical idea. Of course, the present invention extends to these modifications and changes. It is. Hereinafter, the modification is demonstrated.

≪Modification≫
FIG. 8 is a view showing a modification of the method for manufacturing the catalytic converter case according to the embodiment of the present invention, and is a perspective view showing a work cutting position.
For example, as shown in FIG. 8, when the workpiece W is cut (cutting step S <b> 2), the workpiece W may be bent into a U shape and then laser processed. That is, the cutting step S2 shown in FIG. 3 may be performed after the bending step S3. Thus, by performing the cutting step S2 after the bending step S3, when the funnel portion 3 is completed, the material of the workpiece W is accurately taken so that the end portion 3c and the end portion 3d match. Can do.

In the above embodiment, the workpiece W is bent into a substantially U shape in the bending step S3, and then the workpiece W is processed into the shape of the funnel portion 3 at the same time in the matching step S4. May be formed stepwise into a final shape by an aligning step of bending the wire W into a substantially C shape and a drawing finishing step of forming the workpiece W into the shape of the final funnel portion 3.
In that case, as shown in FIG. 7 (b), as shown in FIG. 7 (b), the metal core 8j is inserted inside the work W in the step of combining the work W bent into a U shape in the bending step S3 shown in FIG. 6 (a). The upper and lower dies 8k, 8k (see FIG. 7 (b)) of the press machine 8 are brought close to each other, and the ends W4, W4 (edges) of the workpiece W are matched with each other, thereby making the workpiece W cylindrical. Bend into a C shape.
Next, in the drawing finishing step, the left and right upper molds 8k and 8k are placed close to each other in the horizontal direction while the cored bar 8j (see FIG. 7B) is inserted inside the work W, and the end W4 ( 6), the ends W4 on both sides of the workpiece W are bent and matched to form flange-shaped ends 3c and 3d, and the entire workpiece W is bent to form the final funnel portion 3. Forming process.
In this way, a drawing finishing process may be incorporated to improve the processing accuracy of the flange mating surface and the funnel portion 3 as necessary.

  FIG. 9 is a view showing a modification of the method for manufacturing a catalytic converter case according to the embodiment of the present invention, and FIG. 9A is a view showing a state in which the circumferential ends formed in the flange shape are butted and overlap-welded. (B) is a main part schematic diagram showing a state where the circumferential end portions formed by abutting are butt welded, and (c) is a main part schematic diagram showing a state where the circumferential end portions are overlap-welded. is there.

  As shown in FIG. 9A, the end portions 3c and 3d of the funnel portion 3 are not limited to being formed in a flange shape, butted, welded and fixed. Note that the end portions 3c and 3d having such a flange shape may be welded by arc welding or the like with the ends thereof being edge-joint shapes. Even in such a case, since the welding location A is located outside the funnel portion 3, no spatter is generated inside.

  For example, as shown in FIG. 9B, the end portions 3c and 3d may be formed by abutting end portions 3c1 and 3d1 having no flange. In such a case, the shape of the groove of the butted end portions 3c1 and 3d1 is changed to a shape such as I-type butting, and the outside of the contact surface is welded by arc welding or the like.

  Further, the end portions 3c and 3d may have a lap joint shape in which the end portions 3c2 and 3d2 are overlapped as shown in FIG. 9C, for example. In such a case, since the end portions 3c2 and 3d2 are overlapped and the tip end portion of the end portion 3c2 located outside is fillet welded by arc welding or the like, the welding location A becomes outside the funnel portion 3. The occurrence of spatter in the funnel portion 3 is prevented.

  FIG. 10 is a view showing a modified example of the catalytic converter case according to the embodiment of the present invention. FIG. 10A is a front view of the catalytic converter case showing an example in which the funnel portion is disposed at the inlet and the outlet of the case main body portion. FIG. 4B is an enlarged cross-sectional view of a catalytic converter case showing an example in which a funnel portion is disposed on the outlet side of the case main body.

  The funnel portion 3 may be provided at the inlet and the outlet of the catalytic converter case 1 like the funnel portions 31 and 32 shown in FIG. The angles θ1 and θ2 of the small-diameter portions 31b and 32b with respect to the large-diameter portions 31a and 32a of the funnel portion 31 may be appropriately formed according to the layout of the exhaust pipes 5 and 6 and surrounding devices, and have an elbow shape of 90 degrees. It is not limited to bend-shaped ones. The diameters of the large diameter portions 31a and 32a and the small diameter portions 31b and 32b may be formed so as to coincide with the exhaust pipes 5 and 6 to be connected.

Further, as shown in FIG. 10B, the catalytic converter case 1 may be one in which only the funnel portion 32 is provided at the opening end portion 2b on the outlet side. A manifold 9 may be directly connected to the opening end 2 a on the inlet side of the catalytic converter case 1. By doing so, the catalytic converter case 1 can be disposed corresponding to any layout.
The funnel portions 31 and 32 may be provided with an oxygen concentration detection sensor (not shown) that has a through hole and detects the concentration of oxygen in the exhaust gas.

It is an enlarged front view which shows the catalytic converter case which concerns on embodiment of this invention. It is an expansion perspective view which shows the funnel part of the catalytic converter case which concerns on embodiment of this invention. It is process drawing which shows the manufacturing method of the catalytic converter case which concerns on embodiment of this invention. It is a figure which shows the manufacturing method of the catalytic converter case which concerns on embodiment of this invention, (a) is a perspective view of the workpiece | work which carried out the drawing process, (b) is the principal part outline of the press machine which shows the state at the time of the drawing process of a workpiece | work. FIG. It is a figure which shows the manufacturing method of the catalytic converter case which concerns on embodiment of this invention, (a) is a perspective view of the cut workpiece, (b) is the principal part outline of the press machine which shows the state at the time of the workpiece cutting process FIG. It is a figure which shows the manufacturing method of the catalytic converter case which concerns on embodiment of this invention, (a) is a perspective view of the workpiece | work bent into U shape, (b) is a press machine which shows the state at the time of the bending process of a workpiece | work. FIG. It is a figure which shows the manufacturing method of the catalytic converter case which concerns on embodiment of this invention, (a) is a perspective view of the workpiece | work which bent the edge part of both sides, and formed the flange part, (b) is the alignment process of a workpiece | work. It is a principal part schematic of the press which shows the state of time. It is a figure which shows the modification of the manufacturing method of the catalytic converter case which concerns on embodiment of this invention, and is a perspective view which shows the cutting position of a workpiece | work. It is a figure which shows the modification of the manufacturing method of the catalytic converter case which concerns on embodiment of this invention, (a) is the principal part schematic diagram which shows the state which faced | matched and welded the edge part of the circumferential direction formed in the flange shape, (B) is the principal part schematic which shows the state which carried out the butt welding of the edge part of the circumferential direction formed by butting, (c) is the principal part schematic diagram which shows the state which carried out the overlap welding of the edge part of the circumferential direction. It is a figure which shows the modification of the catalytic converter case which concerns on embodiment of this invention, (a) is a front view of the catalytic converter case which shows an example which has arrange | positioned the funnel part in the inlet_port | entrance and outlet of a case main-body part, (b) ) Is an enlarged cross-sectional view of a catalytic converter case showing an example in which a funnel portion is disposed on the outlet side of the case body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Catalytic converter case 2 Case main-body part 2a, 2b Open end part 3, 31, 32 Funnel part 3a, 31a, 32a Large diameter part 3b, 31b, 32b Small diameter part 3c, 3c1, 3c2, 3d, 3d1, 3d2 End part 4 Catalyst body 5,6 Exhaust pipe 8 Press machine 9 Manifold O Shaft core P Exhaust flow path (pipe)
S1 Drawing process S2 Cutting process S3 Bending process S4 Matching process S5 Welding process S6 Connecting process W Work W1 Curved surface

Claims (3)

A catalytic converter case that houses a catalyst body for purifying exhaust gas of an internal combustion engine,
A cylindrical case main body for storing the catalyst main body;
A funnel part connected to the case body part,
The funnel portion is formed with a small-diameter portion on one opening end side, and a large-diameter portion larger in diameter than the small-diameter portion is formed on the other opening end side with a funnel shape, and the pipe line is curved. Is formed by bending one metal plate into a cylindrical shape,
The end portions on both sides in the circumferential direction protrude toward the outside in a state of being in contact with each other, and are formed into an arcuate flange shape in front view,
The catalytic converter case, wherein the flange-shaped end portion is formed on the inner peripheral surface side formed in the curved shape and joined by welding. The funnel part is formed into a tubular shape by sheet metal pressing,
The end portions on both sides in the circumferential direction are arranged at positions where the distance from the periphery of the large diameter portion to the periphery of the small diameter portion is the shortest distance of the conduit. Catalytic converter case. A method of manufacturing a catalytic converter case according to claim 1 or claim 2,
The funnel is
A drawing step of forming a curved surface-like portion from one large diameter portion to the small diameter portion by drawing from the direction of the axis of the large diameter portion on one workpiece made of the metal plate,
A cutting step of cutting off the excess part of the workpiece by cutting from the direction of the axis of the large-diameter portion ; and
A bending step Ru bent into a substantially U-shape facing the conduit direction by bending in a direction perpendicular to the workpiece to the axial line of the large diameter portion,
Forming the workpiece into a final shape of the funnel by bending the workpiece from a direction perpendicular to the axis of the large-diameter portion into a cylindrical shape and matching the ends on both sides in the circumferential direction. When,
A method of manufacturing a catalytic converter case, comprising: a welding step of welding the end portion to complete the funnel portion .

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