JP3957615B2 - Catalytic converter and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a catalytic converter and a manufacturing method thereof, and more particularly to a catalytic converter having a double structure at an end portion of the catalytic converter and a manufacturing method thereof.
[0002]
[Prior art]
A manufacturing method in the case where the end portion of the conventional catalytic converter has a double structure is shown in FIGS.
As shown in FIG. 10, the conventional catalytic converter 50 includes an outer tube 51, an inner tube 60, and a catalyst 70 in which a heat insulating material 71 is wound around the outer periphery, and the heat insulating material 71 is wound around the outer periphery of the cylindrical portion 52 of the outer tube 51. The inner tube 60 in which the small diameter portion 62 is supported by the inner tube support member 82 from one end of the outer tube 51 fixed by the fixing member 83 of the known spinning device 80 shown in FIG. The roller 81 of the spinning device 80 is pressed against the outer tube 51 and moved in the radial direction and the axial direction by a known drawing process, and the tip is contracted.
[0003]
As a result, the small diameter portion 54 of the outer tube 51 is caulked to the small diameter portion 62 of the inner tube 60 to complete one end of the catalytic converter 50.
Reference numeral 73 denotes an annular space formed between the funnel-shaped cone portion 61 of the inner tube 60 and the funnel-shaped cone portion 53 of the outer tube 51 formed by drawing, and heat inside the catalytic converter 50 is transferred to the outside. Insulating effect that is not transmitted to
Next, the inner tube support member 82 is removed from the small diameter portion 62 of the inner tube 60, the outer tube 51 is loosened by the fixing member 83, the outer tube 51 is turned, and the other tube is fixed again in the same manner. Finalize.
(For example, refer to Patent Document 1).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 2000-265830
[Problems to be solved by the invention]
However, in this case, the inner tube 60 is supported only on the outer end side by the inner tube support member 82 of the spinning device 80, and the large diameter portion of the cone portion 61 is not supported and is in an unstable state. In some cases, inclination or the like may occur inside the tube 51, and the cone portion 53 of the outer tube 51 is drawn by the spinning device 80. When the inner pipe 60 is pressed by a cylinder when it is fixed by drawing, the end surface of the catalyst 70 is damaged, or the joint margin L at the outer end of the inner pipe 60 is insufficient. there were.
Further, the presence of the inner pipe 60 is not only the heat insulating effect by the annular space 73 but also the exhaust gas passing through the catalytic converter 50 passes only through the catalyst 70 without passing through the heat insulating material 71 wound around the outer periphery of the catalyst 70. If the inner tube 60 is inclined with one end being unstable during the drawing process by the spinning device 80 as described above, the guiding effect is lost and the inner tube 60 passes through the catalytic converter 50. There is also a problem that exhaust gas that passes through the heat insulating material 71 and is not sufficiently purified is released into the atmosphere.
[0006]
In view of such a problem, the present invention provides a catalytic converter having a double end structure, and the inner pipe is not inclined inside, and its position is easily adjusted, and the heat insulation in which the exhaust gas is wound around the outer periphery of the catalyst. It is an object of the present invention to provide a catalytic converter that does not pass through a material or a mat.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the catalytic converter of the present invention is a catalytic converter having a cylindrical portion that accommodates a catalyst therein, and is located on the side of the catalyst housing position of the outer tube constituting the cylindrical portion. A funnel-shaped inner tube is disposed at a predetermined interval, and the fitting side end of the inner tube is locked by a convex portion formed on the inner surface of the outer tube, and the end of the outer tube is filtered. A slanted portion and a small diameter portion are formed by drawing so as to be in contact with the outer end surface of the funnel-shaped inner tube .
[0008]
In the present invention configured as described above, since the convex portion is formed on the inner surface of the cylindrical portion that accommodates the catalyst, the inner tube can be easily locked, and the inner tube can be drawn when the outer tube is drawn. There is no slippage.
[0009]
In this case, the convex portion can be formed by deforming the outer tube by pressing from the outside or the inside.
[0010]
Thereby, shaping | molding of a convex part and shaping | molding of the inclination part of the edge part of an outer tube can be performed with one spinning apparatus.
[0011]
Further, the outer periphery of the catalyst can be shielded by the fitting side end portion of the inner tube.
[0012]
Thereby, the exhaust gas passing through the catalytic converter can be reliably guided to the catalyst.
[0013]
In addition, the second invention relates to a method for manufacturing the catalytic converter, wherein the catalyst is accommodated in a cylindrical material constituting the outer tube, and a convex portion is formed on the inner surface of the cylindrical material on the side of the catalyst accommodating position. Then, a funnel-shaped inner tube is inserted from the opening of the tubular material, the fitting side end of the inner tube is locked by the convex portion, and the end of the tubular material is Drawing is performed so as to contact the outer end surface of the inner tube.
[0014]
According to the present invention having the above-described configuration, a convex portion is formed on the inner surface of the cylindrical material to lock the fitting-side end portion of the inner tube, and the inner tube support member of the spinning device is fitted to the outer end portion of the inner tube. After being supported, the outer tube is drawn so that the locked inner tube is not displaced during drawing.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a catalytic converter and a manufacturing method thereof according to the present invention will be described below with reference to the drawings.
[0016]
FIG. 1 shows a completed diagram of the catalytic converter of the present invention. The catalytic converter 1 accommodates the catalyst 3 in the cylindrical portion 21 of the outer tube 20 and has a predetermined interval on the side of the catalyst 3. After supporting the funnel-shaped inner tube 30 having the inclined portion 31 and the small-diameter portion 32 by the convex portion provided on the inner surface of the outer tube 20 cylindrical portion 21, the end portion of the outer tube 20 is contracted by the drawing process by a spinning device and inclined. The portion 22 and the small diameter portion 23 are used.
The end face of the inner pipe 30 is formed in a state protruding from the end face of the outer pipe 20 with a predetermined joint allowance L.
[0017]
Between the outer periphery of the catalyst 3 and the cylindrical portion 21 of the outer tube 20, a mat 4 made of a heat expansion material (vermiculite, meteorite), ceramic fiber, organic binder, or the like is disposed.
The mat 4 is inserted into the outer tube 20 so as to wrap around the outer periphery of the catalyst 3, and plays a role of filling the difference between the outer diameter of the catalyst 3 and the inner diameter of the outer tube 20 whose outer diameter is not constant in processing. It is.
[0018]
The inner tube 30 is manufactured in advance by drawing or pressing, and is filtered from the small diameter portion 32 according to the pipe diameter connected at the use location of the catalytic converter 1 and from the small diameter portion 32 according to the inner diameter of the outer tube 20. It consists of an inclined portion 31 extending in a funnel shape, abuts on the circumferential convex portion 2 formed on the inner surface of the cylindrical portion 21 of the outer tube 20, and the mat 4 is substantially arranged so that exhaust gas does not pass through the mat 4. A cover portion 33 that can be hidden is formed at the end of the inclined portion 31.
In addition to the shape shown in FIG. 1, the shape of the cover portion 33 may be a shape like the cover portions 33 a, 33 b, and 33 c shown in FIGS. 6 (a) to (c).
Reference numeral 34 denotes a peripheral surface portion connected to the outer edge of the cover portion 33.
[0019]
Further, the catalytic converter 1 shown in FIG. 1 has an example in which the inner tube 30 is incorporated at both ends, and the axial center of the cylindrical portion 21 of the outer tube 20 is coincident with the axial center of the small diameter portion 32 of the outer tube 20 and the inner tube 30. Although shown, there is a case where the inner tube 30 is incorporated at one end and the inner tube 30 is not incorporated at the other end, and the axis of the outer tube 20 and the small diameter portion 32 of the inner tube 30 is the center of the catalytic converter 1. When the outer tube 20 is eccentric or inclined with respect to the axial center of the cylindrical portion 21 of the outer tube 20 depending on the location of use, the inclined portions 22 and 31 are conical when the shape of the outer tube 20 is cylindrical or elliptical. Or an elliptical cone.
[0020]
Next, the manufacturing method of the catalytic converter of this invention is demonstrated according to FIG. 2 thru | or FIG.
[0021]
In the manufacturing method of the catalytic converter 1 of the present invention, the catalyst 3 having the mat 4 wound around the outer periphery is accommodated at a central position in the outer tube 20 and fixed by a fixing member (not shown) of a spinning device (not shown) ( (See FIG. 2).
After that, the roller R of the spinning device is pressed against the tube end of the outer tube 20 at an appropriate position on the side of the housing position of the catalyst 3, and the inward movement is performed by only moving in the radial direction without moving in the axial direction. The convex part 2 is formed (refer FIG. 3).
At this time, when the outer tube 20 is a cylindrical material, the convex portion 2 is formed over the entire circumference, but the outer tube 20 is an elliptical cylindrical material (in this case, the inner tube 30 has an elliptical cone shape). .)), The convex portion 2 is formed only at two locations near the maximum outer diameter. However, the convex portion 2 is not provided on the entire inner peripheral surface of the outer tube 20 for supporting the inner tube 30. Needless to say, this is possible if there are two or more locations.
[0022]
Next, the inner tube 30 is formed in the outer tube 20 while the small diameter portion 32 of the inner tube 30 is held by the pressing holding member 7 of the spinning device, by the convex portion 2 formed from the tube end to the inner surface of the outer tube 20. Push until locked (see FIG. 4).
[0023]
Next, the roller R of the spinning device is moved in the axial direction while moving in the radial direction (left side in the direction shown in the figure) to form the inclined portion 22 and the small-diameter portion 23 at the end of the outer tube 20, and the space 5 is formed. Thus, it shape | molds by drawing (refer FIG. 5).
[0024]
The space 5 exhibits a heat insulating effect as in the conventional example, and may be a space as shown in the figure, and the space between the inner tube 30 and the outer tube 20 is pre-filled with a heat insulating material. However, the drawing of the end of the outer tube 20 may be performed.
[0025]
In addition to the case where the convex part 2 is based on the drawing process mentioned above, the method of fixing the L-shaped stopper 6 shown in FIG. 7 to the inner peripheral surface of the outer tube 20 by a fixing means such as welding at a plurality of positions, FIG. As shown in FIG. 4, a plurality of convex portions 2 ′ may be formed on the inner peripheral surface of the outer tube 20 by using impacting means such as punching from the outer peripheral surface of the outer tube 20.
Further, the convex portion 2 can also be formed into an outward convex portion 2 ″ by drawing as shown in FIG. 9. In FIG. 9, the circumferential projection 34A (34A) formed on the circumferential surface portion 34 of the inner tube 30 is formed. ', 34A ") and partial protrusion 34B (34B').
[0026]
As described above, the catalytic converter and the manufacturing method thereof according to the present invention have been described based on the examples thereof. However, the present invention is not limited to the configurations described in the above examples, and may be appropriately selected within the scope of the invention. The configuration can be changed.
[0027]
【The invention's effect】
As described above, according to the present invention, the inner end of the inner tube of the catalytic converter having a double end structure is locked by the convex portion formed on the outer tube, and the outer end of the inner tube is pressed and held by the spinning device. Since the drawing is performed on the end portion of the outer tube after being supported by the inner tube, there is no possibility that the inner tube is displaced during the drawing process. Therefore, the exhaust gas does not pass through the mat wound around the catalyst, and the exhaust gas purification efficiency does not decrease.
[0028]
Also, when the convex part formed on the outer tube is performed by the pressing means, the convex part can be formed by pressing the roller of the spinning device, and the same spinning as the drawing process when forming the inclined part at the outer pipe end part. The apparatus can be used, the work procedure can be simplified, and the product cost can be reduced.
[0029]
Furthermore, when a space is provided between the outer tube and the inner tube, the heat insulating effect of the catalytic converter can be improved, and the space is pre-filled with a heat insulating material and the end of the outer tube is drawn. If it carries out, it has the effect that the improvement of the further heat insulation effect can be aimed at.
[Brief description of the drawings]
FIG. 1 shows a cross-sectional view of a catalytic converter of the present invention.
FIG. 2 is a partial cross-sectional view for explaining the catalytic converter manufacturing method of the present invention.
FIG. 3 is a partial cross-sectional view for explaining the catalytic converter manufacturing method of the present invention.
FIG. 4 is a partial cross-sectional view for explaining the catalytic converter manufacturing method of the present invention.
FIG. 5 is a partial cross-sectional view for explaining the catalytic converter manufacturing method of the present invention.
FIG. 6 is a partial cross-sectional view showing another embodiment of the cover portion formed at the end of the inner tube.
7A and 7B are partial cross-sectional views showing another embodiment of the convex portion, in which FIG. 7A is a side view, and FIG. 7B is a view taken along the line XX of FIG.
FIGS. 8A and 8B are partial cross-sectional views showing another embodiment of the convex portion, in which FIG. 8A is a side view and FIG. 8B is a YY arrow view of FIG.
FIG. 9 is a partial cross-sectional view showing another embodiment of a convex portion and an embodiment of a protrusion engaged therewith.
FIG. 10 shows a cross-sectional view of a conventional catalytic converter.
FIG. 11 is a partial cross-sectional view illustrating a conventional catalytic converter manufacturing method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Catalytic converter 2 Convex part 2 'Convex part 2 "Convex part 3 Catalyst 5 Space 20 Outer pipe 21 Cylindrical part 30 Inner pipe

Claims (4)

In the catalytic converter having a cylindrical portion adapted to accommodate the catalyst therein, a funnel-shaped inner tube is provided at a predetermined interval on the side of the catalyst housing position of the outer tube constituting the cylindrical portion. disposed, the insertion end of the inner tube while engaging the convex portion formed on the inner surface of the outer tube, so as to contact the end of the outer tube to the outer end surface of the funnel-shaped inner tube A catalytic converter characterized by forming an inclined portion and a small diameter portion by drawing .   2. The catalytic converter according to claim 1, wherein the convex portion is formed by deforming the outer tube by pressing from outside or inside.   The catalytic converter according to claim 1 or 2, wherein an outer periphery of the catalyst is shielded by an end portion on the fitting side of the inner pipe.   The catalyst is accommodated inside the cylindrical material constituting the outer tube, a convex portion is formed on the inner surface of the cylindrical material on the side of the catalyst accommodating position, and then the funnel-shaped inner is formed from the opening of the cylindrical material. Insert a tube, lock the fitting side end of the inner tube with the convex portion, and perform drawing so that the end of the cylindrical material is in contact with the outer end surface of the funnel-shaped inner tube A method for producing a catalytic converter, characterized in that:

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