JP6748992B2 - Method of manufacturing catalytic converter - Google Patents

Description

The present invention relates to a method for manufacturing a catalytic converter, and more particularly, to a method for manufacturing a catalytic converter in which a buffer member and a catalyst carrier are press-fitted into a tubular body having a non-circular curved cross section, and spinning is performed on an end portion of the tubular body. Pertain to.

As a method for manufacturing a catalytic converter that is an exhaust gas purifying apparatus for an automobile equipped with an internal combustion engine, a cushioning member and a catalyst carrier are press-fitted into a tubular body having a non-circular curved cross section such as an elliptical shape or a race track shape, and the tubular body is There is known a method of performing a spinning process on the end portion of No. 1 to reduce the diameter of the end portion in a tapered shape. For example, in Patent Document 1 below, "Even if the cross-sectional shape of the work is elliptical or racetrack-shaped, the yield of the work is good, the manufacturing cost can be reduced, the degree of freedom of the shape is high, and the body portion is formed by spinning. "Providing a method for manufacturing a catalytic converter capable of forming a cone portion having a predetermined shape at both ends" (described in paragraph [0006] of Patent Document 1), "the cross-sectional shape in the direction perpendicular to the axis is an ellipse or a racetrack shape". While holding at least one end of the tubular work with the holding device with the holding device, while rotating the roller relative to the work in a state of abutting the one end of the work from the outer peripheral side, the axial direction In the method of manufacturing a catalytic converter container in which the radius of rotation is gradually reduced while being relatively moved to, the holding device has a jig that supports a range of the work that does not contact the roller, and the jig is a shaft. Has a projecting portion that projects in the direction to prevent irregular deformation of the work, and the inner surface of the jig has a supporting surface whose cross-sectional shape in the direction perpendicular to the axis is elliptical or racetrack-shaped." It has been proposed (described in claim 2 of the same document).

On the other hand, Japanese Patent Application Laid-Open No. 2004-242242 discloses that "a conventional catalytic converter manufacturing method requires a press machine and a spinning machine, respectively. Therefore, the equipment cost is increased and the installation area of each machine is required. In addition, there was a problem that the work efficiency had to be reduced because the work had to be attached and detached from the press machine and the spinning machine, and the work had to be transported from the press machine to the spinning machine." In order to solve this, in order to solve this, "a machine main body and a metal holding cylinder provided in the machine main body, in which a catalyst carrier is press-fitted through a holding material, are supported. The holding cylinder is driven to rotate about its axis, and the end of the holding cylinder is formed by being pressed against the outer circumference of the holding cylinder provided on the machine body and rotated by the main shaft. In a spinning machine for a catalytic converter having a roll mount to which a forming roll is attached, in the machine body, the spindle is opposed to the main shaft, and the axis is arranged in a state of being substantially aligned with the axis of the main spindle. A spinning machine is proposed in which a supported holding cylinder is provided with a press-fitting means for press-fitting the catalyst carrier having the holding material attached to its outer periphery in the axial direction thereof (described in the same paragraph [0004]).

Further, in Patent Document 3 below, "a final target machining portion having a central axis which is at least one of eccentricity, inclination, and twist from the non-machining portion of the work with respect to the central axis of the non-machining portion. Up to, a plurality of target machining portions are set, a plurality of machining target axes are set based on the plurality of target machining portions, and one of the plurality of machining target axes and the central axis of the machining target portion of the workpiece are set. Support the work so as to be substantially coaxial, and match the center axis of the processing target portion with each processing target axis of the plurality of processing target axes, and the diameter of the processing target portion at each processing target axis. Is performed to form the final target processed portion shape by performing a spinning process so as to change the value of the workpiece.” A method for forming a different-diameter portion of a work is proposed (paragraph [Patent Document 3]. [0006])).

Japanese Patent No. 3550647 Patent No. 4554062 Japanese Patent No. 3390725

In the method for manufacturing a catalytic converter proposed in Patent Document 1, when the buffer member and the catalyst carrier are press-fitted into the elliptical or racetrack-shaped tubular body, the cross-sectional minor axis of the tubular body is generated by the repulsive force of the buffer member. The side is inflated. Therefore, when the tubular body is mounted on the jig and clamped (grasping), the position in the rotational direction about the axis of the tubular body is not fixed, and the positioning in the rotational direction is incomplete. If the tubular body is gripped in this state, an excessive load may be partially applied, and the catalyst carrier in the tubular body may be damaged. On the other hand, the catalytic converter targeted by Patent Document 2 has a circular cross section, and since the catalytic converter is rotationally driven about its axis, the end shape is coaxial with the holding cylinder (main body of the cylindrical body). However, it is not possible to form an end portion having a central axis that is eccentric, inclined, or twisted with respect to the central axis of the main body as described in Patent Document 3.

Therefore, the present invention provides a method for manufacturing a catalytic converter in which a cushioning member and a catalyst carrier are press-fitted into a tubular body having a non-circular curved cross section, and at least one end of the tubular body is subjected to a spinning process. An object of the present invention is to provide a method of manufacturing a catalytic converter that can form at least a taper portion at one end in a state where the catalyst carrier is appropriately held in a tubular body without being applied with an excessive load by processing.

In order to achieve the above object, the present invention, in the main body of the tubular body having a non-circular curved cross-section, while press-fitting the buffer member and the catalyst carrier, at least one end of the tubular body is subjected to spinning. In the method of manufacturing a catalytic converter, the first step of holding the main body of the tubular body by a clamp member and the cushioning member and the catalyst for the tubular body held by the clamp member. A second step of press-fitting a carrier into the body, and spinning at least one end of the tubular body having the buffer member and the catalyst carrier in the body and held by the clamp member was carried out, have a third step of forming at least a tapered portion at the one end, the clamping member, at least two split mold having parallel opposed surfaces to a plane including the axis of the tubular body The main body portion of the tubular body is held while maintaining a predetermined minute gap between the facing surfaces of the two split molds . It should be noted that a small diameter portion having a circular cross section may be formed continuously with the tapered portion at the one end portion.

Further, in a state where the cylindrical body is held by the clamp member, the one end portion in a state where at least the tapered portion is formed by the spinning work is cut, and a tip of the one end portion is predetermined. A fourth step of forming into a shape may be included.

In the method of manufacturing a catalytic converter, the clamp member, and those with a biasing member for biasing in a direction coming close to the two split molds to each other, between the facing surface by the urging force of the urging member Further, it is preferable that the main body portion of the tubular body is held while maintaining the minute gap .

Since the present invention is configured as described above, it has the following effects. That is, in the method of manufacturing the catalytic converter of the present invention, the first step of holding the main body of the tubular body by the clamp member and the cushioning member and the catalyst carrier for the tubular body held by the clamp member. A second step of press-fitting into the main body portion, and at least one end portion of the tubular body having the buffer member and the catalyst carrier in the main body portion and held by the clamp member is subjected to spinning processing, and at least one end portion have a third step of forming a tapered portion, the clamp member comprises at least two split mold having parallel opposed surfaces to a plane including the axis of the cylindrical body, between the opposing surfaces of the split mold Since the main body of the tubular body is held while maintaining a predetermined minute gap , the buffer member and the catalyst carrier can be appropriately press-fitted and held in the tubular body having a non-circular curved cross section. Then, subsequently, by spinning at least one end of the cylindrical body, the catalyst converter can be easily manufactured without applying an excessive load to the catalyst carrier. Further, in a state in which the tubular member is held by the clamp member and at least a tapered portion is formed by spinning, a cutting process is performed to form a tip of the one end into a predetermined shape. By including the step, it is possible to smoothly and reliably cut the one end portion of the tubular body.

State in the manufacturing method of the catalytic converter, and those with a biasing member for biasing in a direction coming close to each other two split mold, which was maintained small gap between the facing surfaces by the biasing force of the biasing member If it is configured to hold the main body of the tubular body, the buffer member and the catalyst carrier press-fitted into the tubular body can be properly held, and the catalyst carrier inside the tubular body is not damaged .

It is a front view showing a clamp member used for a manufacturing method of a catalytic converter concerning one embodiment of the present invention, and a catalytic converter in the state where it was held by the clamp member. It is a side view showing a clamp member used for a manufacturing method of a catalytic converter concerning one embodiment of the present invention, and a catalytic converter in the state where it was held by the clamp member. FIG. 3 is a plan view showing a clamp member used in the method for manufacturing the catalytic converter according to the embodiment of the present invention, and the catalytic converter held by the clamp member. FIG. 3 is a cross-sectional view showing a clamp member used in the method for manufacturing the catalytic converter according to the embodiment of the present invention, and the catalytic converter held by the clamp member. FIG. 5 is a process drawing of the method for manufacturing the catalytic converter according to the embodiment of the present invention. It is a front view and a side view showing a clamp device and a spinning device used for a manufacturing method of a catalytic converter concerning one embodiment of the present invention. FIG. 5 is a front view and a side view showing a clamped state of the work in the method for manufacturing the catalytic converter according to the embodiment of the present invention. FIG. 5 is a front view and a side view showing a spinning process on one end portion of the work in the method for manufacturing the catalytic converter according to the embodiment of the present invention. FIG. 5 is a front view and a side view showing the work reversing operation in the method for manufacturing the catalytic converter according to the embodiment of the present invention. FIG. 5 is a front view and a side view showing the rotation operation of the clamp device in the method for manufacturing the catalytic converter according to the embodiment of the present invention. FIG. 6 is a front view and a side view showing a spinning process on the other end of the work in the method for manufacturing the catalytic converter according to the embodiment of the present invention. It is a front view and a side view showing a clamp device and a spinning device used for a manufacturing method of a catalytic converter concerning other embodiments of the present invention. It is a front view and a side view showing a clamped state of a work in a manufacturing method of a catalytic converter concerning other embodiments of the present invention. It is a front view which shows the clamp member of the other aspect used for this invention, and the catalytic converter in the state hold|maintained by this clamp member. It is a side view which shows the clamp member of the other aspect used for this invention, and the catalytic converter in the state hold|maintained by this clamp member. It is a front view which shows the clamp member of the further another aspect used for this invention, and the catalytic converter in the state hold|maintained by this clamp member. It is a side view which shows the clamp member of the further another aspect used for this invention, and the catalytic converter in the state hold|maintained by this clamp member.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. As an example of the final product manufactured by the method for manufacturing the catalytic converter according to the embodiment of the present invention, the catalytic converter 10 is shown in the lowermost stage (P5) of FIG. The catalytic converter 10 includes a cylindrical main body 11 having a non-circular curved cross section, taper portions 12 and 13 and small diameter portions 14 and 15 integrally formed at both ends thereof. As shown in the vertical cross section, a cushioning mat 30, which is a cushioning member, is wound around the catalyst carrier 20 and is press-fitted into the main body 11. In FIG. 5, (A) on the left side shows the front surface of the catalytic converter 10, and (B) on the right side shows the right side surface thereof.

As shown in the uppermost stage (P0) of FIG. 5, the work W to be processed in the present embodiment is a tubular body made of stainless steel having an elliptical cross section, but has a racetrack shape as a non-circular curved cross section. It may be a cross section. Further, instead of the stainless steel pipe as the work W, another metal pipe may be used. The tubular body means the work W of the material, the catalytic converter 10 of the final product, and the outer case of the intermediate processed product, and the body parts thereof have the same shape with an elliptical cross section, and the body part in each figure. Shown by 11.

In the present embodiment, the clamp members (40, 50) shown in FIGS. 1 to 4 are used to manufacture the above catalytic converter. The clamp members (40, 50) are two split dies having opposing surfaces parallel to a plane including the axis of the main body 11 of the work W (cylindrical body), that is, the upper clamp member 40 and the lower clamp member 50. The main body 11 of the work W is held in a state in which a predetermined minute gap (CL) is maintained between the opposing surfaces of the clamp members (40, 50). As shown in FIG. 1, a total of eight compression springs (represented by S) are provided as urging members for urging the upper clamp member 40 and the lower clamp member 50 in directions toward each other. The urging force of the spring S is configured to hold the main body 11 while maintaining a minute gap (CL) between the opposing surfaces of the clamp members (40, 50).

In the present embodiment, the bottomed groove-shaped support portions 41 to 44 and the support portions 51 to 54, which respectively project outward and open at the outer side surfaces, are provided at four locations on the side wall portions of the upper clamp member 40 and the lower clamp member 50. They are integrally formed, and semi-cylindrical outer peripheral surfaces 40c and 50c are formed between them. With the compression spring S accommodated in each groove of the supporting portions 41 to 44 and the supporting portions 51 to 54, a bolt (represented by B) is arranged so as to pass through each bottom surface. A nut (representatively represented by N) is screwed into the shaft and the supporting portions 41, 51 and the like facing each other are fastened. At this time, the upper clamp member 40 and the lower clamp member 50 are held in a state in which a minute gap (CL) is maintained between the facing surfaces of the upper clamp member 40 and the lower clamp member 50. For example, between the support portions 41 and 51, the compression springs S are housed in a state in which the bottom surfaces of both support portions face each other, and the nuts N are screwed into the bolts B that pass through these and are held at predetermined positions. ..

The manufacturing method of the present invention has three basic steps (P1) to (P3) shown in FIG. That is, first, in the first step (P1), the main body portion 11 of the work W (cylindrical body) is maintained by the clamp members (40, 50) at a predetermined minute gap (CL) between the opposing surfaces thereof. Maintained in the state. Next, in the second step (P2), the main body of the catalyst carrier 20 in which the buffer mat 30 is wound around the work W (cylindrical body) held by the clamp members (40, 50). It is press-fitted into the part 11. Then, in the third step (P3), the work W (tube) having the catalyst carrier 20 with the cushioning mat 30 wound therein is held in the main body 11 and held by the clamp members (40, 50). The object is attached to a clamp device 2 described later, and is held in a state (CL=0) in which the opposing surfaces of both clamp members (40, 50) are in close contact with each other. In this state, both ends of the work W (cylindrical body) are subjected to spinning as will be described later, and taper parts 12 and 13 and small diameter parts 14 and 15 are formed at the both ends.

Thus, according to the present embodiment, both ends of the catalytic converter 10 in a state where the catalyst carrier 20 and the buffer mat 30 are press-fitted into the main body 11 having an elliptical cross section are subjected to spinning, and the tapered portion 12 is formed. , 13 and the small-diameter portions 14 and 15 are integrally formed (in (P3) of FIG. 5, each tip portion shows the state before cutting). The axial centers of the tapered portions 12 and 13 and the small diameter portions 14 and 15 can be either coaxial or non-coaxial (eccentric, inclined, twisted) with respect to the axial center of the main body 11 (center portion).

In the present embodiment, further, as shown in the fourth step (P4) of FIG. 5, the workpiece W (cylindrical body) is held by the clamp members (40, 50) and is subjected to spinning processing. Cutting processing is performed on the respective tip portions in the state where the tapered portions 12 and 13 and the small diameter portions 14 and 15 are formed (the cutting points are indicated by broken lines in (P3) of FIG. 5), and the respective tip portions are predetermined. Formed into a shape. Thus, the catalytic converter 10 shown in the lowermost stage (P5) of FIG. 5 is formed, and the final product is obtained.

The spinning process in the third step (P3) will be described below with reference to FIGS. 6 to 10. In each of FIGS. 6 to 10, (A) on the left side shows the front surface of the spinning processing apparatus, and (B) on the right side shows the right side surface thereof. As shown in FIG. 6, the spinning device used in the present embodiment holds the spinning device 1 that performs the spinning process on one end of the workpiece W to be processed and the clamp members (40, 50). A clamp device 2 and a chuck device (not shown) that is disposed on the other end side of the work W and that attaches and detaches the work W to and from the clamp device 2 are arranged in parallel. Then, under the control of a controller (not shown) serving as a drive control means, the spinning device 1 is relatively displaced with respect to the clamp device 2 to perform the spinning process on the end portion of the work W, and the taper portions 12 and 13. And small-diameter portions 14 and 15 are formed. The spinning device 1 is movable along the X-axis (the left-right direction in FIG. 6), and for example, three rollers (represented by RL) taper portions 12 and 13 at the end of the work W. In addition, the small diameter portions 14 and 15 are formed, and the structure thereof is the same as that of the device described in the above-mentioned Patent Document 3, and therefore description thereof will be omitted.

As shown in FIG. 6, the clamp device 2 according to the present embodiment has U-shaped holders 6 and 7, the holder 6 holds an upper clamp member 40, and the holder 7 has a lower clamp member 40. 50 is retained. The inner peripheral surfaces (indicated by 6c and 7c in FIG. 6(B) of FIG. 6B) of the holding members 6 and 7 that face each other are semi-cylinders that closely contact the semi-cylindrical outer peripheral surfaces 40c and 50c of the clamp members (40 and 50). It is formed into a shape. For example, a hydraulically driven cylinder 9 is fixed to the holder 6, and the cylinder 9 is configured to vertically drive the holder 6 (and thus the upper clamp member 40) via the rod 8. At the time of mounting and dismounting the work W and the like, the upper clamp member 40 is driven to move upward (a raised state is shown in FIG. 9). Further, as shown in FIG. 9, the work W is rotatably supported around its axis by a chuck device (not shown), and clamped by a rotary drive device (not shown) as shown in FIG. The device 2 is supported rotatably around an axis perpendicular to the axis of the rod 8.

When the holder 6 is driven downward from the state shown in FIG. 6 and the upper clamp member 40 is driven so as to come into close contact with the lower clamp member 50, as shown in FIG. 11 is firmly held in a state where the minute gap (CL) between the upper clamp member 40 and the lower clamp member 50 has disappeared, and is reliably held with a holding force that can withstand the spinning process. Subsequently, as shown in FIG. 8, while setting a target target machining portion shape for each cycle for the work W, and gradually reducing the diameter of one end portion of the workpiece W by successive spinning processing that gradually approaches a desired shape, A taper portion 12 that is inclined with respect to the main body portion 11 is formed integrally with the main body portion 11, and a small diameter portion 14 having a circular cross section is formed, and the state shown in FIG. Then, when the work W held by the clamp members (40, 50) is driven to rotate about 180° about the vertical axis (the axis perpendicular to the paper surface of FIG. 9), the work W is as shown in FIG. The state will be reversed to. Then, as shown in FIG. 11, the other end portion (the left end portion shown in FIG. 11A) of the work W held by the clamp members (40, 50) is subjected to spinning, and the main body portion 11 A tapered portion 13 that is inclined with respect to is formed, and a small diameter portion 15 having a circular cross section is formed.

Further, when the end portion after the spinning processing is trimmed by an arbitrary cutting means (not shown) such as laser processing and the tip portions of the small-diameter portions 14 and 15 are cut off, FIG. As shown in FIG. 3, the small-diameter portions 14 and 15 each have a final shape having an open end surface perpendicular to the axis. After that, the holding state of the main body 11 by the clamp members (40, 50) is released, and the processed catalytic converter 10 (product) shown in the lowermost stage (P5) of FIG. 5 is taken out. The trimming process may be performed individually after the spinning process on each end, but in the present embodiment, the work W (cylindrical body) is held by the clamp members (40, 50). Since it is maintained, the tip portions of the small diameter portions 14 and 15 can be accurately and easily formed even if the trim processing is performed after the spinning processing of both end portions.

As described above, according to the present embodiment, since the tapered portions 12 and 13 and the small diameter portions 14 and 15 can be continuously formed in both ends of the work W in one step, the both ends can be formed. Processing time can be significantly reduced compared to individual processing. Further, as shown in (P4) of FIG. 5, while being held by the clamp members (40, 50), trimming is performed on the end portions after the spinning process to form the small-diameter portions 14, 15 in the final shape. By doing so, not only the cutting time can be shortened, but also the cutting process can be performed accurately and smoothly.

12 and 13 show a manufacturing method according to another embodiment of the present invention. When it is not necessary to rotate the work W as shown in FIG. 9, for example, a small diameter portion 14 (and a tapered portion 12) is used. When the shaft center of the small diameter portion 15 (and the taper portion 13) is on the same plane, it is simplified like the clamp member (40x, 50x) and the holders (6x, 7x) of the clamp device 2 are illustrated. If the common shape shown in FIG. 12 is used, the cost can be reduced. With respect to other configurations, substantially the same members as those in the above-described embodiment are designated by the same reference numerals, and description thereof will be omitted.

14 and 15 show another mode of the clamp member. If the shape allows the main body 11 of the work W to be properly held, the clamp member (40y, 50y) is formed. Good. 16 and 17 show still another mode of the clamp member, which is formed like the clamp members (40z, 50z), and these are manually operated by the bolt B (the bolt B is centered around its tip). It is also possible to have a detachable structure by tilting operation). Regarding the other configurations in FIGS. 14 to 17, members that are substantially the same as those in the above-described embodiment are assigned the same reference numerals, and description thereof is omitted.

In any of the above-mentioned embodiments, it is possible to appropriately combine automation techniques. For example, the robot device can be used for attachment/detachment of the clamp member, conveyance between processes while holding the clamp member, and the like. At that time, if various sensors such as a pressure sensor and an acceleration sensor are mounted on the clamp member, the detected values can be used in the automation technology and can be fed back to the machining process. The method described in Japanese Patent No. 5495496 may be used as a spinning processing method for forming a small diameter portion and a tapered portion having an eccentric/inclined/twisted axis with respect to the axis of the main body.

1 Spinning Device 2 Clamping Device 6, 6x Holder 7, 7x Holder 8 Rod 9 Cylinder 10 Catalyst Converter 11 Main Body 12, 13 Tapered Part 14, 15 Small Diameter Part 20 Catalyst Carrier 30 Buffer Mat (Cushion Member)
40, 40x, 40y, 40z Upper clamp member (clamp member)
41, 42, 43, 44 Supports 50, 50x, 50y, 50z Lower clamp member (clamp member)
51, 52, 53, 54 Support portion B Bolt N Nut S Compression spring (biasing member)
W work (cylindrical body)

Claims (3)

A method of manufacturing a catalytic converter in which a buffer member and a catalyst carrier are press-fitted into a main body of a tubular body having a non-circular curved cross section, and spinning is performed on at least one end of the tubular body,
A first step of holding the main body portion of the tubular body by a clamp member;
A second step of press-fitting the buffer member and the catalyst carrier into the main body with respect to the cylindrical body held by the clamp member;
A structure in which the buffer member and the catalyst carrier are provided in the main body portion, at least one end portion of the cylindrical body held by the clamp member is subjected to spinning processing, and at least one tapered portion is formed at the one end portion; 3 of the process possess,
The clamp member is
At least two split molds having opposing surfaces parallel to a plane including the axis of the tubular body,
A method for manufacturing a catalytic converter, characterized in that the main body portion of the tubular body is held in a state in which a predetermined minute gap is maintained between the facing surfaces of the two split molds . In the state where the cylindrical body is held by the clamp member, cutting is performed on the one end in a state where at least the tapered portion is formed by the spinning process, and the tip of the one end is formed into a predetermined shape. The method of manufacturing a catalytic converter according to claim 1, further comprising a fourth step of forming. The clamp member is
A biasing member for biasing the two split molds in directions approaching each other,
The method according to claim 1 or 2 catalytic converter, wherein the holding of said body portion of said tubular body while maintaining the small gap between the opposing surfaces by the biasing force of the biasing member.

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