JP5551425B2 - Catalytic converter manufacturing method and catalytic converter - Google Patents

Description

  The present invention belongs to the technical field of catalytic converter manufacturing methods and exhaust gas purification catalytic converters.

  As this type of technology, the technology described in Patent Document 1 below is disclosed. In this publication, a catalyst carrier is inserted into a metal shell (outer cylinder) and pressurized from the outside of the metal shell to reduce the diameter and heat at a high temperature.

JP 2003-74336 A

The catalytic converter has a metal catalyst carrier in which a corrugated plate made of stainless steel foil and a flat plate are wound in an outer cylinder and wound to form a thin exhaust gas passage, and the surface is coated with a purification catalyst. The exhaust gas is purified while passing through the gas passage. There is a diffusion bonding method as a method of bonding these stainless steel foils. In diffusion bonding, it is necessary to heat the bonding surface while applying pressure in order to bring the bonding members into close contact with each other. A metal catalyst carrier is accommodated in the outer cylinder, and when the outer cylinder and the metal catalyst carrier are pressurized from the outside and reduced in diameter, a part of the metal catalyst carrier is buckled, and a recess is formed between the outer cylinder and the metal catalyst carrier. May occur. If this concave portion is concentrated in one place, a portion where the exhaust gas passes without being affected by the catalyst is formed, and the ventilation resistance is lower than that of the exhaust gas passage. Therefore, the amount of exhaust gas that passes through the recess without passing through the exhaust gas passage in the metal catalyst carrier and passes through without touching the catalyst may increase, and the purification function of the catalytic converter may deteriorate.
The present invention has been made paying attention to the above-mentioned problems, and an object of the present invention is to provide a method for manufacturing a catalytic converter that suppresses a reduction in purification function of the catalytic converter, and a catalytic converter.

In order to achieve the above object, in the first aspect of the invention, the first step of stacking the corrugated and flat stainless steel foils into a cylindrical roll shape and the metal catalyst carrier having an inner diameter of the cylindrical roll shape. A second step of inserting the metal catalyst carrier into a cylindrical outer cylinder having a large diameter with a columnar rod interposed therebetween, and reducing the diameter of the outer cylinder and the metal catalyst carrier from the outer peripheral side of the outer cylinder. And a fourth step of performing diffusion bonding by applying heat to the outer cylinder and the metal catalyst carrier.

According to a second aspect of the present invention, a substantially cylindrical outer cylinder and a cylindrical roll-shaped metal catalyst carrier inserted into the outer cylinder are provided, and corrugated plates and flat plates of the metal catalyst carrier are formed by diffusion bonding. In the catalytic converter in which the junction points are connected, a plurality of rods are inserted in a cylindrical shape between the outer cylinder and the metal catalyst carrier .

In the first and second aspects of the present invention, by using the rod, the metal catalyst carrier can be provided with a concave portion at a position where it abuts on the convex portion provided in advance on the inner periphery of the outer cylinder, and many concave portions are provided. Therefore, it is possible to make each concave portion small and relatively equidistant. Therefore, it is possible to eliminate the portion through which the exhaust gas passes without being influenced by the catalyst, and to suppress the amount of exhaust gas that bypasses the exhaust gas passage and escapes to the recess, thereby improving the purification function of the catalytic converter. it can.

1 is a perspective view of a catalytic converter of Example 1. FIG. 1 is a perspective view of a metal catalyst carrier of Example 1. FIG. 2 is an enlarged view of an end surface of a metal catalyst carrier of Example 1. FIG. It is a perspective view of the rod of Example 1. 3 is an axial view of an outer cylinder, a metal catalyst carrier, and a rod of Example 1. FIG. FIG. 6 is a cross-sectional view of the outer cylinder, the metal catalyst carrier, and the rod of Example 1 taken along line AA in FIG. 5. It is a figure which shows the diameter reduction process by the chuck mechanism of Example 1. FIG. FIG. 3 is an axial view of the metal catalyst carrier and the outer cylinder of Example 1. 6 is a cross-sectional view of an outer cylinder, a metal catalyst carrier, and a rod of Example 2. FIG. FIG. 3 is an axial view of the catalytic converter of Example 2.

[Example 1]
A method for manufacturing the catalytic converter 9 of Example 1 and the catalytic converter 9 will be described.

[Composition of catalytic converter]
FIG. 1 is a perspective view of the catalytic converter 9. The catalytic converter 9 has a cylindrical outer cylinder 5 and a metal catalyst carrier 1 inserted into the outer cylinder 5. A plurality (20 in the first embodiment) of recesses 8 are formed on the outer periphery of the metal catalyst carrier 1.
FIG. 2 is a perspective view of the metal catalyst carrier 1, and FIG. 3 is an enlarged view of an end surface of the metal catalyst carrier 1. The metal catalyst carrier 1 is formed into a roll shape by winding a corrugated metal foil 2 made of a stainless steel having a thickness of about 50 [μm] and a flat metal foil 3 in a stacked state. . A space formed by the corrugated metal foil 2 and the flat metal foil 3 on the flat plate is connected to the axial direction of the metal catalyst carrier 1 and serves as an exhaust gas passage. A large number of slit holes 4 are formed in the metal foils 2 and 3 in order to improve the purification function by allowing the exhaust gas to pass not only in the axial direction but also in the radial direction of the metal catalyst carrier 1. The slit hole shape may be, for example, a round hole shape in addition to the long hole. The slit hole 4 may be omitted.
Further, the winding end portions of the metal foils 2 and 3 are fixed to the outermost peripheral portion by spot welding or the like.

  The outer cylinder 5 is made of metal and is formed in a cylindrical shape. The inner diameter of the outer cylinder 5 is slightly larger than that of the roll-shaped metal catalyst carrier 1. Further, the axial length of the outer cylinder 5 is formed to be about the same as or longer than the axial length of the metal catalyst carrier 1. The thickness of the outer cylinder 5 is about 1.2 [mm] to 2 [mm].

  FIG. 4 is a perspective view of the rod 6. The rod 6 is formed in a columnar shape and is higher than the axial length of the metal catalyst carrier 1. Further, the diameter is made larger than the amplitude of the wave in consideration of the spring back of the corrugated metal foil 2 of the metal catalyst carrier 1 when extracted.

[Production method of catalytic converter]
5 is a view of the state in which the metal catalyst carrier 1 and the rod 6 are inserted into the inner circumference of the outer cylinder 5 as viewed from the axial direction. FIG. 6 is a diagram showing the metal catalyst carrier 1 and the rod on the inner circumference of the outer cylinder 5 shown in FIG. It is the figure which cut | disconnected the state which inserted 6 and along the AA line to the axial direction.

  First, the roll-shaped metal catalyst carrier 1 is produced by winding the corrugated metal foil 2 and the plate-shaped metal foil 3 in multiple layers.

  Next, as shown in FIGS. 5 and 6, a plurality of (examples) are formed by winding the metal catalyst carrier 1 around the inner circumference of the outer cylinder 5 and a brazing foil material around a part of the outer circumference of the metal catalyst carrier 1. 1) 20 rods 6) are inserted alongside. At this time, one end of the rod 6 protrudes outward in the axial direction of the outer cylinder 5. Temporary bonding may be performed by applying an adhesive that does not interfere with diffusion bonding, which will be described later, by evaporation to the outer periphery of the metal catalyst carrier or the rod 6 by heating. Further, if the end of each rod 6 is connected to a flexible belt and wound in a laver winding shape, it becomes easy to pull out after the diameter reduction.

  FIG. 7 is a view showing a diameter reducing process by the chuck mechanism 7. As shown in FIG. 7, the metal catalyst carrier 1 and the rod 6 are inserted into the inner periphery of the outer cylinder 5 and inserted into the inner periphery of the chuck mechanism 7. The chuck mechanism 7 reduces the diameter of the outer cylinder 5 by applying a force to the outer cylinder 5 radially inward. By this step, the outer periphery of the metal catalyst carrier 1 and the inner periphery of the outer cylinder 5 are brought into close contact with each other, and the metal foils 2 and 3 wound in a roll shape are also pressed and brought into close contact with each other. After the diameter reduction process, the rod 6 is pulled out.

  FIG. 8 is a diagram of the metal catalyst carrier 1 and the outer cylinder 5 after the rod 6 is pulled out, as viewed from the axial direction. As shown in FIG. 8, traces (recesses 8) are formed on the outer periphery of the metal catalyst carrier 1 by pulling out the rod 6. The metal catalyst carrier 1 and the outer cylinder 5 that have been pressed in the direction of diameter reduction by the chuck mechanism 7 are heated to diffusely join the contact points of the metal catalyst carrier, and the outer cylinder 5 and the metal catalyst carrier 1 are Joined by molten brazing material. Thereafter, an exhaust purification catalyst is coated on the surface of the metal catalyst carrier. Further, if the rod 6 is pulled out after heating, the displacement of the metal catalyst carrier can be more reliably prevented until joining.

[Action]
In diffusion bonding, it is necessary to heat while applying pressure to bring the bonding members into close contact with each other. However, since the metal catalyst carrier 1 is formed from the metal foils 2 and 3 having a very small thickness (50 [μm] in the first embodiment), the diameter of the metal catalyst carrier 1 is reduced to the unjoined metal catalyst carrier 1. When pressure is applied, the outer periphery of the metal catalyst carrier 1 may buckle, and a recess may be formed between the outer cylinder 5 and the metal catalyst carrier 1. If this concave portion is large, the amount of exhaust gas passing through the concave portion increases without passing through the exhaust gas passage of the metal catalyst carrier 1 coated with the catalyst, and exhaust gas that passes without touching the catalyst is generated. There was a possibility that the purification function of No. 9 might be lowered.

Therefore, in Example 1, as a method of manufacturing the catalytic converter 9, a cylindrical outer cylinder having an inner diameter larger than that of the metal catalyst carrier 1 having a cylindrical roll shape and having a plurality of convex portions (rods 6) on the inner periphery. 5, the metal catalyst carrier 1 is inserted, the outer cylinder 5 and the metal catalyst carrier 1 are reduced in diameter from the outer peripheral side of the outer cylinder 5, and diffusion bonding is performed by applying heat to the outer cylinder 5 and the metal catalyst carrier 1. It was. Thereafter, an exhaust purification catalyst is coated on the surface of the metal catalyst carrier.
Thereby, the recessed part 8 can be provided in the part which the convex part (rod 6) of the outer periphery of the outer cylinder 5 and the metal catalyst carrier 1 contact | abut, and since many recessed parts 8 can be provided equally, it is one by one. The two recesses 8 can be made small and provided at relatively equal intervals. Therefore, the amount of exhaust gas that bypasses the exhaust gas passage and escapes to the recess 8 can be suppressed, and the exhaust gas that passes through the recess 8 without being affected by the purification catalyst can be eliminated. The purification function of the converter 9 can be improved.

In Example 1, as a method of manufacturing the catalytic converter 9, the cylindrical rod 6 together with the metal catalyst carrier 1 is inserted into the outer cylinder 5, so that a convex portion is provided on the inner periphery of the outer cylinder 5.
Thereby, a convex part can be provided in the inner periphery of the outer cylinder 5 using a simple-shaped member.

In Example 1, as a method for manufacturing the catalytic converter 9, a step of removing the rod 6 was provided.
Thereby, the catalytic converter 9 can be manufactured without leaving the rod 6 which is an extra member in the catalytic converter 9.

In the catalytic converter 9 of Example 1, a plurality of recesses 8 are provided on the outer peripheral surface of the metal catalyst carrier 1.
By providing a large number of each of the recesses 8, the amount of exhaust gas escaping to the recesses 8 can be suppressed, and exhaust gas flowing without being affected by the catalyst is eliminated in the recesses 8. The reduction of the purification function can be suppressed.

〔effect〕
The manufacturing method of the catalytic converter 9 of Example 1 and the effects of the catalytic converter 9 are listed below.

(1) As a manufacturing method of the catalytic converter 9, a first step of winding the metal catalyst carrier 1 in a cylindrical roll shape, and an inner diameter larger than that of the metal catalyst carrier 1 in a cylindrical roll shape, and a plurality of protrusions on the inner circumference A second step of inserting the metal catalyst carrier 1 into the substantially cylindrical outer cylinder 5 having the portion (rod 6), and a third step of reducing the diameter of the outer cylinder 5 and the metal catalyst carrier 1 from the outer peripheral side of the outer cylinder 5. And a fourth step of performing diffusion bonding by applying heat to the outer cylinder 5 and the metal catalyst carrier 1.
Accordingly, the concave portions 8 can be provided at positions where the metal catalyst carrier 1 contacts the convex portion (rod 6) portion on the inner periphery of the outer cylinder 5, and a large number of the concave portions 8 can be provided uniformly. The concave portions 8 can be made small and provided at relatively equal intervals. Therefore, the amount of exhaust gas that bypasses the exhaust gas passage and escapes to the concave portion 8 can be suppressed, and the exhaust gas that flows without being influenced by the catalyst in the concave portion 8 is eliminated, so that the purification function of the catalytic converter 9 is improved. be able to. Since the cross-sectional shape of the rod 6 is round, cracks do not occur in the metal catalyst carrier made of the metal foil even if the rod 6 is pressed from the outer periphery and reduced in diameter. The cross-sectional shape is not limited to a circle, and an elliptical shape, a triangular shape, or the like can be selected according to the diameter of the metal catalyst carrier.

(2) As a manufacturing method of the catalytic converter 9, in the second step, the substantially cylindrical rod 6 is inserted into the outer cylinder 5 together with the metal catalyst carrier 1, thereby providing a convex portion on the inner periphery of the outer cylinder 5.
Therefore, a convex part can be provided in the inner periphery of the outer cylinder 5 using a simple-shaped member.

(3) As a manufacturing method of the catalytic converter 9, a step of removing the rod 6 was provided after the third step.
Therefore, the catalytic converter 9 can be manufactured without leaving the rod 6 which is an extra member in the catalytic converter 9.

(4) Catalytic converter comprising a substantially cylindrical outer cylinder 5 and a cylindrical roll-shaped metal catalyst carrier 1 inserted in the inner periphery of the outer cylinder 5 and joining the metal catalyst carrier 1 by diffusion bonding. 1, a plurality of recesses 8 are provided on the outer peripheral surface of the metal catalyst carrier 1.
By providing a large number of each of the recesses 8, the amount of exhaust gas that bypasses the exhaust gas passage and escapes to the recesses 8 can be suppressed, and exhaust gas flowing down without being affected by the purification catalyst can be eliminated. Therefore, it is possible to suppress a decrease in the purification function of the catalytic converter 9.

[Example 2]
A method for manufacturing the catalytic converter 9 of Example 2 and the catalytic converter 9 will be described. In the method of manufacturing the catalytic converter 9 according to the second embodiment, the step of removing the rod 6 from between the metal catalyst carrier 1 and the outer cylinder 5 is omitted, and the diffusion bonding is performed with the rod 6 remaining. 1 and different. The catalytic converter 9 according to the second embodiment is different from the first embodiment in that a rod 6 is inserted between the metal catalyst carrier 1 and the outer cylinder 5.
The description of the same configuration as that of the first embodiment is omitted, and the same reference numerals are given.

  FIG. 9 is a view in which the state in which the metal catalyst carrier 1 and the rod 6 are inserted into the inner periphery of the outer cylinder 5 is cut in the axial direction in the same manner as FIG. As shown in FIG. 9, the metal catalyst carrier 1 and a plurality of (20 in the first embodiment) rods 6 are inserted along the inner circumference of the outer cylinder 5 along the outer circumference of the metal catalyst carrier 1. The length of the rod 6 in the axial direction is shorter than the length of the metal catalyst carrier 1 in the axial direction, and is accommodated in the outer cylinder 5 with the rod 6 inserted. In this state, as described in Embodiment 1, the outer diameter of the outer cylinder 5 is reduced by applying a force radially inward to the outer cylinder 5 by the chuck mechanism 7. By this step, the outer periphery of the metal catalyst carrier 1 and the inner periphery of the outer cylinder 5 are in close contact with each other, and the metal foils 2 and 3 wound in a roll shape are also in close contact with each other. Thereafter, in Example 2, diffusion bonding is performed while the rod 6 is left between the metal catalyst carrier 1 and the outer cylinder 5.

  FIG. 10 shows the catalytic converter 9 viewed from the axial direction after the metal catalyst carrier 1 and the outer cylinder 5 are heated and diffusion-bonded. As shown in FIG. 10, the rod 6 is inserted into the concave portion 8 of the metal catalyst carrier 1 after diffusion bonding.

[Action]
In Example 2, as a method for manufacturing the catalytic converter 9, diffusion bonding was performed while the rod 6 was inserted.
Thereby, the process of removing the rod 6 can be omitted, and the manufacturing process can be simplified.
In Example 2, as the catalytic converter 9, the rod 6 arranged in a substantially cylindrical shape is inserted between the outer cylinder 5 and the metal catalyst 1 at the positions of the plurality of recesses 8 of the metal catalyst carrier 1. Left behind.
Thereby, the process of removing the rod 6 can be omitted, and the manufacturing process can be simplified.

〔effect〕
The manufacturing method of the catalytic converter 9 of Example 2 and the effects of the catalytic converter 9 are listed below.

(5) In the method of manufacturing the catalytic converter 9, diffusion bonding is performed with the rod 6 inserted.
Therefore, the process of removing the rod 6 can be omitted, and the manufacturing process can be simplified.

(6) The positions of the recesses 8 of the metal catalyst carrier 1, between the outer cylinder 5 and the metal catalyst 1 was inserted rod 6 in a cylindrical shape.
Accordingly, the concave portion 8 of the metal catalyst carrier 1 can be closed by the rod 6 without collapsing the concave portion 8 of the metal catalyst carrier 1 before performing diffusion bonding. Therefore, the amount of exhaust gas escaping to the recess 8 can be suppressed, and a reduction in the purification function of the catalytic converter 9 can be suppressed.

[Other Examples]
As mentioned above, although the manufacturing method of the catalytic converter 9 of this invention and the catalytic converter 9 were demonstrated based on the Example, the concrete structure of this invention is not limited to an Example, It concerns on each claim of a claim Design changes and additions are allowed without departing from the scope of the invention.

For example, in Example 1 and Example 2 , the metal foils 2 and 3 are provided with the slit holes 4, but the arrangement, number of formations, shapes, and the like of the slit holes 4 can be appropriately set. Moreover, the setting without a slit hole is also possible.
In Examples 1 and 2 , the thickness of the metal foils 2 and 3 is about 50 [μm], and the thickness of the outer cylinder 5 is about 1.2 [mm] to 2 [mm]. It can be set appropriately.
Further, in Example 1 and Example 2 , diffusion bonding is performed in a state where the chuck mechanism 7 is pressurized in the diameter reducing direction, but after the diameter reducing process by the chuck mechanism 7 is completed, the state is removed from the chuck mechanism 7. Alternatively, diffusion bonding may be performed.
Moreover, in Example 1 and Example 2 , although the 20 recessed parts 8 are formed in the outer periphery of the metal catalyst support 1, this number may be set suitably.
In the first and second embodiments, 20 rods 6 are used, but this number may be set as appropriate .
In the first embodiment, one end of the rod 6 protrudes outward in the axial direction of the outer cylinder 5, but the rod 6 may be housed in the outer cylinder 5. In this case, the rod 6 may be extracted using a jig or the like that pushes out the rod 6.

1 Metal catalyst carrier 2 Corrugated metal foil 3 Flat metal foil 5 Outer cylinder 6 Rod 8 Recess 9 Catalytic converter 10 Projection

Claims (3)

A first step of forming the metal catalyst carrier 1 in a cylindrical roll shape by winding the metal catalyst carrier 1 in a state where the corrugated metal foil 2 and the flat metal foil 3 are stacked;
A second step of inserting the metal catalyst carrier into a cylindrical outer cylinder having an inner diameter larger than the outer diameter of the metal catalyst carrier with a columnar rod interposed therebetween;
A third step of reducing the diameter of the outer cylinder and the metal catalyst carrier from the outer peripheral side of the outer cylinder;
A fourth step of performing diffusion bonding by applying heat to the outer cylinder and the metal catalyst carrier;
A method for producing a catalytic converter, comprising: In the manufacturing method of the catalytic converter of Claim 1,
A method for producing a catalytic converter, comprising the step of removing the rod after the third step. In the manufacturing method of the catalytic converter of Claim 1,
In the fourth step, diffusion bonding is performed with the rod inserted, and the method for manufacturing a catalytic converter is characterized in that:

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