JPH08103665A - Production of catalytic converter - Google Patents

Abstract

PURPOSE: To provide a method for producing a catalytic converter to produce a metallic carrier with the heat capacity lowered and the purifying performance immediately after the start of an engine improved at a low cost with high productivity. CONSTITUTION: This catalytic converter consists of a metallic carrier 40 formed with the flat sheet 2 and corrugated sheet 3, a cylindrical part covering the periphery of the carrier 40 and a flange. A slit 4 extending in the orthogonal direction to the waste gas flow direction is formed on at least one exhaust upstream side of the metallic flat sheet 2 or corrugated sheet 3, and the flat sheet 2 and the corrugated sheet 3 are alternately laminated and wound with a shaft 23 as the center to constitute the carrier 40. A foil as the material for the flat sheet 2 and corrugated sheet 3 is inserted and fixed in the slit extending in the axial direction including the center of the shaft 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a catalytic converter for purifying exhaust gas of an internal combustion engine, and more particularly to a method for manufacturing a catalytic converter used as a catalytic converter for automobiles.

[0002]

2. Description of the Related Art Conventionally, for example, a ceramic monolith catalytic converter made of cordierite or the like is interposed in an exhaust path of an automobile engine, and C contained in exhaust gas is contained.
Oxides such as O, HC, and NOx are converted into harmless gas or water. However, in recent years
As the performance of automobiles has increased, catalytic converters made of heat-resistant stainless steel (hereinafter,
A “catalytic converter”) has been developed, and this catalytic converter has a substantially honeycomb structure composed of a thin flat plate of stainless steel having a thickness of about 0.03 to 0.08 mm and a corrugated plate. A method of forming the flat plate and the corrugated plate into a substantially honeycomb structure and a technique of joining the flat plate and the corrugated plate are considered important for ensuring durability and reducing costs.

For example, as a method of forming a substantially honeycomb structure,
The metal honeycomb winding method disclosed in Japanese Unexamined Patent Publication No. 4-260445 forms a cylindrical body by winding a flat plate on a winding mandrel for at least one turn and joining the flat plate,
In this method, a corrugated plate is fed between the peripheral surface of the cylindrical body and the flat plate and is wound together with the flat plate. Further, as a bonding technique of a substantially honeycomb structure, for example, a method of manufacturing a catalyst substance-supporting matrix disclosed in Japanese Patent Publication No. 63-44466 discloses that a brazing material is applied to a desired bonding portion at the time of winding, and after winding is completed. It is a brazing method. In addition, JP-A-3-101841
The method for manufacturing a metal carrier for an exhaust gas purifying catalyst for automobiles disclosed in the publication is a method in which a flat plate and a corrugated plate which are wound and overlapped at the same time are spot-welded by resistance welding at a contact portion.

On the other hand, in order for the catalytic converter to properly purify the exhaust gas, the metal carrier wound by the method disclosed in each of the above-mentioned patents reaches a temperature of 300 ° C. or higher and is carried on the metal carrier. The catalytic material needs to be activated. However, the temperature of this metal carrier is CO, H
Since it rises due to heat transfer of high-temperature exhaust gas containing C, NOx, etc., it is necessary to suppress CO, HC, NOx, etc. discharged in several tens of seconds until the metal carrier reaches the activation temperature of the catalyst substance. It is essential to raise the temperature of the carrier in a short time.

Therefore, the heating device for the honeycomb catalytic converter disclosed in Japanese Patent Laid-Open No. 4-136512 is
A voltage is applied between the side electrodes provided on the outer peripheral surface of the honeycomb carrier and the central electrode provided at the center of the honeycomb carrier, and the temperature of the honeycomb carrier is raised in a short time by electrically heating the honeycomb carrier. ing.

[0006]

However, according to the metal honeycomb winding method disclosed in Japanese Patent Laid-Open No. 4-260445 as a method for forming a substantially honeycomb structure, a material foil is used at the beginning of winding the metal honeycomb. When a flat plate and a corrugated plate are wound without being fixed to the shaft of the core material, there is a problem that the material foil and the shaft slide with each other and the rotation of the shaft is not transmitted to the material foil. Further, when the material foil is fixed and wound on the shaft, there is a problem that it is difficult to remove the metal honeycomb from the shaft after the winding is completed.

In addition, as a joining technique of a substantially honeycomb structure,
According to the method for producing a catalyst substance-supporting matrix disclosed in Japanese Patent Publication No. 63-44466, a brazing material is continuously applied in the longitudinal direction of a steel sheet which is a material of the honeycomb body, so that a flat plate and a corrugated plate are formed. However, there is a problem that the brazing filler metal adheres to a portion that does not come into contact with each other, and the amount of the brazing filler metal used becomes larger than necessary. In order to apply the brazing material only to the contact portion between the flat plate and the corrugated plate, a means for detecting the phase of the corrugated plate is required, which complicates the structure of the manufacturing apparatus. Further, JP-A-3-10184
According to the method for manufacturing a metal carrier for an exhaust gas purifying catalyst for automobiles disclosed in Japanese Patent Publication No. 1, since spot welding is performed at a contact portion between a flat plate and a corrugated sheet at the same time as winding, a contact portion to be spot welded, that is, a corrugated sheet. A detection means for accurately detecting the valleys and peaks of the is essential. Therefore, there is a problem that it is difficult to realize this manufacturing method. In addition,
In the method for producing a metal carrier for an exhaust gas purifying catalyst for automobiles disclosed in Japanese Patent Application Laid-Open No. 3-101841, there is no specific description in the specification and drawings of the means for detecting the contact portion between the flat plate and the corrugated plate.

On the other hand, in order to raise the temperature of the honeycomb carrier in a short time, according to the electric heating device of the honeycomb catalytic converter disclosed in Japanese Patent Laid-Open No. 4-136412, the side electrodes, the central portion and the honeycomb carrier are In addition to the need for an insulating structure that insulates the case from the side electrodes, an alternator dedicated to the honeycomb carrier and a battery are also required, resulting in a large system configuration and increasing cost.

The present invention has been made in order to solve such a problem, and manufactures a catalytic converter for manufacturing a metal carrier having a low heat capacity and improved purification performance immediately after engine start at low cost and high productivity. The purpose is to provide a method.

[0010]

According to a first aspect of the present invention, there is provided a method for manufacturing a catalytic converter according to the present invention, which is arranged in an exhaust path of an internal combustion engine and is orthogonal to an exhaust gas flow direction. A plurality of slits extending to the exhaust gas upstream side of at least one of a flat plate or corrugated plate made of metal, the flat plate and the corrugated plate are alternately superposed and formed by winding around a core material A method of manufacturing a catalytic converter having a body, comprising a material foil having a flat plate portion and a corrugated plate portion, which is a material of the honeycomb body, in a gap between the core members extending along an axial direction including a center of the core member. Is inserted and fixed, and a step of winding the material foil around the core material as a shaft.

A method of manufacturing a catalytic converter according to a second aspect of the present invention is the method of manufacturing a catalytic converter according to the first aspect, wherein the flat plate and the corrugated plate are made of Fe.
It is characterized by being made of -Cr-Al-REM stainless steel. A method for manufacturing a catalytic converter according to a third aspect of the present invention is the method for manufacturing a catalytic converter according to the first or second aspect, wherein the core material has a dividing surface that is divided into two in a plane including the axis thereof. However, the flat plate or the corrugated plate is sandwiched and supported by the respective divided surfaces.

A method of manufacturing a catalytic converter according to a fourth aspect of the present invention is the method of manufacturing a catalytic converter according to the first, second or third aspect, wherein the outer peripheral wall of the core member is partially or wholly. It is characterized in that it is formed in a wave shape in the circumferential direction. A method for manufacturing a catalytic converter according to a fifth aspect of the present invention is the method for manufacturing a catalytic converter according to the first, second or third aspect, wherein the outer peripheral wall of the core member is partially or wholly circumferentially. It is characterized in that it is formed in a polygonal shape.

The method of manufacturing a catalytic converter according to a sixth aspect of the present invention is the method of manufacturing a catalytic converter according to any one of the first to fifth aspects, wherein the gap between the cores is the material. It is characterized in that the thickness is equal to or less than that of two foils. According to a seventh aspect of the present invention, there is provided the method of manufacturing the catalytic converter according to any one of the first to sixth aspects, wherein the core material has a diameter of 2 mm to 5 mm. Characterize.

According to the eighth aspect of the present invention, there is provided a method for producing a catalytic converter according to any one of the first to seventh aspects, wherein the material foil includes one honeycomb body. It is characterized by comprising the flat plate portion and the corrugated plate portion having a length required for constituting.
A method for manufacturing a catalytic converter according to claim 9 of the present invention is the method for manufacturing a catalytic converter according to any one of claims 1 to 8, wherein the material foil includes the flat plate portion and the corrugated plate portion. Is formed by joining.

A method of manufacturing a catalytic converter according to a tenth aspect of the present invention is the method of manufacturing a catalytic converter according to any one of the first to eighth aspects, wherein the material foil includes the flat plate portion and the wave. It is characterized in that it is integrally formed with the plate portion. A method of manufacturing a catalytic converter according to claim 11 of the present invention is the method of manufacturing a catalytic converter according to claim 10, wherein the gap between the core members is
It is characterized in that it is not more than the thickness of one sheet of the material foil.

A method of manufacturing a catalytic converter according to a twelfth aspect of the present invention is the method of manufacturing a catalytic converter according to any one of the first to eleventh aspects, wherein the material foil is fixed to the core material. The position is a boundary portion between the flat plate portion and the corrugated plate portion. The method for manufacturing a catalytic converter according to claim 13 of the present invention is
The method for manufacturing a catalytic converter according to any one of claims 1 to 11, wherein a position at which the material foil is fixed to the core material is from a boundary portion between the flat plate portion and the corrugated plate portion toward the flat plate portion. In addition, it is characterized in that the core material is located at a position separated by ½ or more of the outer peripheral length of the core material.

The method of manufacturing a catalytic converter according to a fourteenth aspect of the present invention is the method of manufacturing a catalytic converter according to any one of the first to eighth and tenth to thirteenth aspects, wherein the material foil is the flat plate. And the corrugated plate portion are fixed to the core material without being joined to each other. A method of manufacturing a catalytic converter according to a fifteenth aspect of the present invention is the method of manufacturing a catalytic converter according to any one of the third to fourteenth aspects, wherein the divided surface of the core material has a concave portion or a convex portion. Are formed.

A method of manufacturing a catalytic converter according to a sixteenth aspect of the present invention is the method of manufacturing a catalytic converter according to the fifteenth aspect, wherein the material foil has holes that can be engaged with the concave portions or the convex portions. A part is formed. A method of manufacturing a catalytic converter according to claim 17 of the present invention is the method of manufacturing a catalytic converter according to any one of claims 1 to 16, wherein the flat plate and the corrugated plate are wound while being wound. The contact portion between the flat plate and the corrugated plate is spot-welded or seam-welded by a laser or an electron beam, and the welding position is detected by a contact sensor.

According to the eighteenth aspect of the present invention, in the method for producing the catalytic converter according to the seventeenth aspect, the contact type sensor includes the welding position based on rotation of a gear meshing with the corrugated plate. Is detected. A method for manufacturing a catalytic converter according to claim 19 according to the present invention is the method for manufacturing a catalytic converter according to any one of claims 1 to 18, wherein a circumferential length of the slit formed in the corrugated plate is set. Further, a specific dimensional relationship determined geometrically is not provided between the slit pitch of the slits and the wave pitch of the corrugated plate.

[0020]

According to the method for manufacturing a catalytic converter of the present invention, since the plurality of slits are formed on the exhaust upstream side of at least one of the flat plate and the corrugated plate constituting the honeycomb body, the heat capacity of the honeycomb body is increased. Can be reduced. As a result, there is an effect that a catalytic converter having a low heat capacity can be obtained.

Further, according to the method of manufacturing the catalytic converter of the present invention, since the plurality of slits are formed in the honeycomb body to reduce the heat capacity, the temperature is raised to the activation temperature of the supported catalyst in a short time. be able to. As a result, the catalyst is activated in a short time immediately after the internal combustion engine is started, and the exhaust gas purification performance is improved. Further, according to the method of manufacturing the catalytic converter of the present invention, the material foil is fitted and fixed in this gap of the core material having a gap in the axial direction, so that the material foil can be easily set on the core material. Further, after being wound around the core material, the honeycomb body after the winding can be easily removed. As a result, workability is improved and work man-hours can be reduced, which has an effect of reducing cost.

Furthermore, according to the method of manufacturing the catalytic converter of the present invention, the welding position of the flat plate and the corrugated plate can be detected by the contact type sensor. Therefore, the flat plate and the corrugated plate are welded by the laser or the electron beam according to the detection timing. can do. Thereby, the winding can be continuously performed while welding the flat plate and the corrugated plate without stopping the rotation of the core material that winds the flat plate and the corrugated plate. This has the effect of improving production efficiency.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. A method of manufacturing a catalytic converter according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 2, the catalytic converter 1 includes a metal carrier 40 including a flat plate 2 and a corrugated plate 3, a cylindrical portion 8 that covers the outer periphery of the metal carrier 40, and a flange attached to the outer peripheral wall of the cylindrical portion 8. It is composed of 12 and.

The metal carrier 40 has a shape in which flat plates 2 and corrugated plates 3 are alternately superposed and wound in a spiral shape. Both the flat plate 2 and the corrugated plate 3 forming the metal carrier 40 are, for example, 18 to 24 wt% Cr and 4.5 to Al.
5.5 wt%, rare earth element (REM) is 0.1 to 0.2
It is a heat-resistant stainless steel foil having a composition of Fe-Cr-Al with wt% and balance Fe. Flat plate 2 and corrugated plate 3 before winding
Has a plate width 50a of 60 mm and a plate thickness of 0.03 to
It is formed in a band shape of 0.20 mm. By using the heat-resistant stainless steel foil having such a composition as the material of the flat plate 2 and the corrugated plate 3, it is possible to obtain the metal carrier 40 that sufficiently withstands the exhaust gas at 900 ° C.

As shown in FIGS. 3 and 5, the flat plate 2 and the corrugated plate 3 each have a slit portion 4 formed from a substantially central portion in the axial direction toward one end portion. Here, since the developed corrugated plate 3 and the flat plate 2 have the same shape, FIG. 5 shows the developed shape of the flat plate 2 as a representative. A gap 50b, which is a welding margin, is provided at one end of the flat plate 2 for joining the flat plate 2 and the corrugated plate 3, as will be described later, and the slit portion 4 is provided in a range of a width 50c from a position separated by the gap 50b. Has been formed. If the axial length of the metal carrier 40 is about 3 to 5 mm, this welding margin does not hinder the temperature rise of the metal carrier 40. In addition, the slit portion 4 is formed in a range of 5 to 60% of the axial length from the exhaust gas upstream side of the metal carrier 40 toward the downstream direction, so that the entire area of the metal carrier 40 is about 20 seconds immediately after the engine is started. It can be activated and sufficient purification performance can be obtained. In this embodiment, the interval 50b is, for example, 3 mm, and the width 50c is, for example, 3 mm.
It is 1.2 mm.

As shown in FIG. 6, the rectangular slit formed in the slit portion 4 is formed, for example, by the following dimensions. Slit width w = 3 mm Slit height h = 1.2 mm Orthogonal slit interval D = 1 mm Axial slit interval H = 0.8 mm This rectangular slit is an interval D orthogonal to the axial direction of the metal carrier 40. Are continuously formed, and are also continuously formed at intervals H in the axial direction. Further, the slits adjacent to each other in the axial direction are positioned so as to be offset from each other by (w + D) / 2.

In the present embodiment, a rectangular slit is formed in the slit portion 4, but the present invention is not limited to this, and for example, as in the modification 1 shown in FIG. 7, a substantially rhombic slit. May be formed in the slit portion 44. Also,
In the present embodiment, the slit portions 4 are formed so that the rectangular slits are positioned alternately. However, the present invention is not limited to this, and for example, as in Modification 2 shown in FIG. The slit portions 45 may be formed so that the shaped slits have the same positional relationship in the axial direction without being staggered in the axial direction of the metal carrier 40. The slit portion 45 increases the rigidity of the metal carrier 40 and has a high natural frequency, so that the durability can be improved.

The slit width w and the slit height h of the slits of the respective shapes forming the slit portions 4, 44 and 45 are h: w.
By setting the ratio to be 1: 5 or less, a natural frequency that sufficiently satisfies the strength required for the metal carrier 40 can be obtained. Further, by forming the slits in the slit portions 4, 44 and 45 so that the total opening area of the slits is 30 to 50% of the total area of the slit portion, sufficient purification is performed immediately after the engine is started. Performance can be secured.

The corrugated plate 3 has a repeating pitch of 4.9 m, for example.
m, and the height is 1.7 mm, which corresponds to the amplitude of the wave. As will be described later, the flat plate 2 and the corrugated plate 3 are wound so that after winding, the slit portions 4 are located on the upstream side of the exhaust gas. Simultaneously with this winding, the flat plate 2 and the corrugated plate 3 in which the slit portion 4 is not formed are joined near both ends. This joining is performed in a portion where the crests or troughs of the corrugated sheet 3 come into contact with the flat plate 2, and laser beam welding, resistance welding,
It is done by brazing.

As shown in FIGS. 2 to 4, the metal carrier 40 composed of the rolled flat plate 2 and the corrugated plate 3 is covered with a cylindrical outer cylinder 8 made of, for example, heat resistant stainless steel SUS430. There is. The outer cylinder 8 is formed so that the void 9 can be secured around the metal carrier 40 in which the slit portion 4 is formed. The void 51a of the void portion 9 is, for example, 1.5 mm, and holds a void having the same height as the corrugated plate 3. Outer cylinder 8 covering the exhaust gas downstream side of the metal carrier 40
A notch 10 extending along the axial direction of the metal carrier 40 is formed in a part of the. The notch 10 is formed in the outer cylinder 8
Eight locations are formed at 45 ° intervals in the circumferential direction.

The metal carrier 40 and the outer cylinder 8 are radiated with a laser beam from the outside of the outer cylinder 8 to the circumferential portion of the outer cylinder 8 excluding the cutout portion 10 so that the metal carrier 40 and the outer cylinder 8 are not in contact with each other. The inner peripheral wall of the cylinder 8 is welded and fixed. The joining of the metal carrier 40 and the outer cylinder 8 is not limited to laser beam welding, but may be brazing. 2 and 3 show welding marks 11 formed by laser beam welding. When the metal carrier 40 and the outer cylinder 8 are joined, weld cracks may occur on the corrugated plate 3 side due to the difference in heat capacity between the outer cylinder 8 and the corrugated plate 3 located at the outermost periphery of the metal carrier 40. Therefore, when welding is performed by laser beam welding, welding cracks on the corrugated sheet 3 side can be prevented by arranging two corrugated sheets 3 on the outermost periphery of the metal carrier 40 so as to overlap each other. Further, when brazing, it is preferable to position the flat plate 2 on the outermost periphery of the metal carrier 40 in order to secure a sufficient brazing area.

On the outer peripheral wall of the outer cylinder 8 covering the exhaust gas upstream side of the metal carrier 40, for example, heat resistant stainless steel SUS430
The flange-shaped flange 12 made of is fixed by welding, and the welding mark 1
3 are formed. For the flange 12, the same material as that of the outer cylinder 8 is selected in consideration of weldability, and in order to secure higher weldability, the outer cylinder 8 and the flange 12 are welded by a γ-Al ₂ O ₃ coat described later. And a step before the catalyst supporting step.

Next, a method of manufacturing the metal carrier 40 will be described with reference to FIGS.
It will be described in detail with reference to FIG. As shown in FIG. 11, the shaft 23 is located at the boundary between the flat plate 2 and the corrugated plate 3, and the shaft 23 rotates so that the flat plate 2 and the corrugated plate 3 are alternately wound around the shaft 23. . As shown in FIG.
The cylindrical shaft 23 is formed with a slit 23a extending along the axis. If the diameter of the shaft 23 is larger than 5 mm, a gap may occur between the shaft 23 and the flat plate 2 during winding, and the diameter is 2 m.
If it is smaller than m, the strength of the shaft 23 is lowered, and thus twisting may occur. Therefore, the diameter of the shaft 23 is set to 2 to 5 mm, for example.
When the material foil 26 is formed by forming one continuous flat plate halfway into a corrugated plate shape, or as described later, the flat plate 2 and the corrugated plate 3 are formed.
When the material foil 26 is formed by joining and
The width 23b of a is set to be equal to or less than the thickness of one flat plate 2. Further, when the flat plate 2 and the corrugated plate 3 are laminated to form the material foil 26, the thickness is set to be equal to or less than the thickness of two flat plates 2. Thereby, the boundary portion between the flat plate 2 and the corrugated plate 3 can be sandwiched and supported by the slit 23a. The length of the slit 23a with respect to the axial direction of the shaft 23 is set to correspond to the plate width 50a of the flat plate 2.

As shown in FIGS. 10 and 11, the material foil 26 is formed by joining the flat plate 2 and the corrugated plate 3 by spot welding or the like before winding. Further, the flat plate 2 and the corrugated plate 3 may be laminated to each other to form the material foil 26 without being joined. The material foil 26 is supported by being sandwiched by the shaft 23 by fitting the boundary portion between the flat plate 2 and the corrugated plate 3 into the slit 23a. Therefore, it is not necessary to connect the flat plate 2 and the corrugated plate 3 before winding by sandwiching the superposed part of the flat plate 2 and the corrugated plate 3 with the slit 23a narrower than the thickness of the superposed part, thus reducing the number of steps. Will be possible.

As shown in FIGS. 12 and 13, the corrugated plate 3
Is provided with a non-wavy portion 3a in which a corrugated shape having a width corresponding to a half circumference or more of the outer circumference of the shaft 23 is provided, and the flat plate 2 and the corrugated plate 3 are fixed by welding, It is sandwiched by a slit 23a at a position deviated to the flat plate 2 side from the boundary portion with Then, since the flat plate 2 can be wound more than half of the outer circumference of the shaft 23, the flat plate 2 can be wound on the innermost circumference.
It can be configured only and no looseness occurs in winding around the shaft 23. Therefore, the flat plate 2 and the corrugated plate 3 can be reliably wound. In this embodiment, the diameter of the shaft 23 is 3 mm and the non-wavy portion 3a is 5 mm.

Further, as shown in FIG. 12, a material foil 26 obtained by forming a continuous flat plate into a corrugated plate halfway may be sandwiched between the shafts 23 in the same manner as described above. In this embodiment,
Although the material foil 26 is sandwiched between the slits 23a provided in the shaft 23, the present invention is not limited to this. For example, as in Modification 3 shown in FIG. 14, from the semi-cylindrical shaft members 24a and 24b. Split surface 2 of the shaft 24
The material foil 26 may be sandwiched by 4c.
In addition, as in Modification 4 shown in FIG. 15, the shaft member 2
5a, 25b on the respective divided surfaces 25c, the recesses 25a,
You may use the shaft 25 which formed the convex part 25b, and in this case, like the modification 5 shown in FIG.
The shaft 25 is attached to the material foil 27 made of the flat plate 2 in which the hole portion 27a engaged with the convex portion 25b is formed. This prevents the shaft 25 and the material foil 27 from being displaced during winding.

Further, although the shaft 23 formed in a cylindrical shape is used in this embodiment, the present invention is not limited to this, and for example, a semi-cylindrical shape as in Modification 6 shown in FIG. The shaft 37 including the shaft member 37a and the shaft member 37b having a corrugated outer peripheral wall adapted to the outer shape of the corrugated plate 3, or a shaft having a polygonal outer peripheral wall may be used. As a result, the position deviation between the shaft 37 and the material foil 26 can be prevented during winding, and the winding around the shaft 37 does not become loose. Therefore, the flat plate 2 and the corrugated plate 3 can be reliably wound.

As shown in FIG. 1, a metal carrier manufacturing apparatus 3
0 is composed of a press machine 31, rollers 37a and 37b, a YAG laser welding machine 32 and the like. A flat plate material foil roll 28 and a corrugated plate material foil roll 29 around which a material foil which is the material of the flat plate 2 or the corrugated plate 3 is wound are set in a metal carrier manufacturing apparatus 30. This flat plate material foil roll 2
8. The slit portions 4 processed by the press 31 are formed in the material foils respectively guided from the material foil roll 29 for corrugated sheet. The material foil guided from the flat plate material foil roll 28 by the formation of the slit portion 4 is the flat plate portion 2 before winding.
c. On the other hand, among the material foils in which the slit portions 4 are formed, the material foil guided from the corrugated sheet material foil roll 29 is further corrugated by the rollers 37a and 37b to form the corrugated sheet portion 3c before winding. Become.

As described above, the flat plate 2 and the corrugated plate 3 having the slits 4 are attached to the shaft 23, and then the flat plate 2 and the corrugated plate 3 are rotated by the rotation of the shaft 23 driven by a motor (not shown). The layers are wound while being stacked so that they are alternately located. At this time, at the same time as winding, the flat plate 2
And the corrugated plate 3 are welded together to join the flat plate 2 and the corrugated plate 3.
Bonding between the flat plate 2 and the corrugated plate 3 is performed by a YAG laser head 34 that irradiates laser light from two opposing directions. Y
The YAG laser welder 32 and the YAG laser head 34 are arranged so that the laser light emitted from the AG laser welder 32 is evenly split by a beam splitter (not shown) and transmitted to the YAG laser head 34 having a focusing optical system. It is connected by an optical fiber cable 33.

In the present embodiment, the number of branches by the beam splitter is two, but the present invention is not limited to this, and the number of branches corresponding to the number of welding points, for example, three branches, four branches, etc. good. The welding position performed by the YAG laser welding machine 32 is the contact portion between the flat plate 2 and the corrugated plate 3, that is, the contact portion between the peak portion of the corrugated plate 3 and the flat plate 2, and the valley portion of the corrugated plate 3 and the flat plate 2. Is the contact portion of. As shown in FIG.
In order to accurately detect this contact portion, a detection gear 35 having an outer peripheral wall that engages in a corrugated manner with the corrugated plate 3 meshes with the corrugated plate 3. At the center of the detection gear 35, the detection gear 35
A shaft of an encoder 36 for detecting the position of the corrugated plate 3 from the rotation angle of is attached to form a contact sensor 39. Further, the contact sensor 39 has a moving unit (not shown) that is linearly movable from the center of the shaft 23 toward the outer side in the radial direction. The moving means has a structure in which the contact type sensor 39 is pressed toward the center of the shaft 23 by a biasing means (not shown) such as a spring or air pressure. Therefore, the winding of the flat plate 2 and the corrugated plate 3 progresses, and the flat plate 2 wound
Even if the diameter of the corrugated plate 3 (hereinafter referred to as "workpiece") increases, the contact sensor 39 moves to the outside in the radial direction of the workpiece, so that winding is not hindered. Further, by measuring the amount of movement of the contact type sensor 39 in the radial direction during winding, it is possible to control the distance between the YAG laser head 34 and the work and adjust the focal length. As described above, by using the contact-type sensor 39 having a simple structure, the welding position can be accurately detected at a low cost as compared with the case where the non-contact-type sensor is used. Further, as compared with the case where the non-contact type sensor is used, the contact type sensor can improve the reliability of the detection signal because the noise is less mixed.

Furthermore, when forming the material foil 26, the corrugated plate 3 is used.
By making the axial length of the corrugated plate longer than the axial length of the flat plate 2, only the corrugated plate 3 can be projected to one end of the work during winding. Therefore, when the flat plate 2 has to be welded to the outer side of the corrugated plate 3, the detection gear 35 is meshed with the protruding portion of the corrugated plate 3 at a position on the opposite side with the shaft 23 interposed therebetween. The position of the corrugated plate 3 can be similarly detected.

The contact type sensor 39 having the above-described structure detects the contact portion between the flat plate 2 and the corrugated plate 3, and the YAG laser head 34 irradiates the laser beam in accordance with the detection signal, and the flat plate 2 and the corrugated plate 3 are radiated. The abutting portion of is welded by laser. At this time, it is desirable that the flat plate 2 and the corrugated plate 3 be continuously wound by the rotation of the shaft 23, and it is not necessary to stop the winding each time the laser light is irradiated.

As described above, the flat plate 2 and the corrugated plate 3 are wound, the slit portion 4 is formed at one end side, and the peaks or valleys of the corrugated plate 3 and the flat plate 2 are laser-welded. A metal carrier can be obtained. In the present embodiment, the case where the flat plate 2 and the corrugated plate 3 are spot-welded by the YAG laser welding machine 32 or the like has been described, but the present invention is not limited to this, and the flat plate 2 and the corrugated plate are corrugated by brazing, for example. It is also possible to weld it to the plate 3. When the flat plate 2 and the corrugated sheet 3 are welded by brazing, the corrugated sheet 3 is obtained by removing the YAG laser welding machine 32, the optical fiber cable 33, and the YAG laser head 34 from the configuration shown in FIG.
It becomes possible by adding a device for applying a brazing material to both surfaces of the. The welding position of the flat plate 2 and the corrugated plate 3 is the same as the above-mentioned YAG.
Similar to the laser welding by the laser welding machine 32 or the like, it can be detected by the contact type sensor 39. As a result, welding can be performed by applying the brazing filler metal only to the necessary portions, which has an effect of reducing the amount of the brazing filler metal used and an effect of reducing the cost.

Next, the catalyst supporting step of supporting the catalyst on the metal carrier 40 will be described. 800-12
By heating the metal carrier 40 at 00 ° C. for 1 to 10 hours, an oxide of aluminum is deposited on the surfaces of the flat plate 2 and the corrugated plate 3 that form the metal carrier 40. This heat treatment is performed for the purpose of suppressing peeling of the γ-Al ₂ O ₃ coat, and is to increase the surface area by forming alumina whiskers on the surfaces of the flat plate 2 and the corrugated plate 3. This allows
This heat treatment is preferable because high reliability can be obtained. After this heat treatment, the metal carrier 40 is impregnated in a slurry containing γ-Al ₂ O ₃ and baked. Thereby, the surfaces of the flat plate 2 and the corrugated plate 3 are γ-A.
l ₂ O ₃ coated.

After forming the γ-Al ₂ O ₃ layer, the metal carrier 40 is impregnated in an aqueous solution in which, for example, platinum, rhodium, palladium, etc. are dissolved by a catalyst supporting step and is baked again. As a result, the γ-Al ₂ O ₃ coated flat plate 2,
Platinum, rhodium, palladium or the like is carried on the surface of the corrugated plate 3. The metal carrier 40 assembled by the above steps is
It functions as a catalytic converter 1 that can be attached to the exhaust path of an automobile.

Next, a state in which the catalytic converter 1 is attached to the exhaust path of the automobile will be described with reference to FIGS. As shown in FIGS. 19 and 20, V8, 4000
Eight exhaust manifolds derived from the engine 5 which is an internal combustion engine of cc are collected in groups of four,
The two exhaust manifolds 6a assembled together,
6b is configured as an exhaust path of the engine.

As shown in FIGS. 20 and 21, in the catalytic converter 1, the flange 12 of the catalytic converter 1 is mounted by the bolts 21 between the exhaust manifold mounting flange 14a and the start caster list mounting flange 14b via the gasket 15. Has been. A start caster list 7 having a large capacity of 1300 cc is arranged immediately below the catalytic converter 1. The exhaust pipes 22 connected to the downstream side of the two start caster lists 7 are further assembled into one, and then connected to a 1000 cc main caster list (not shown).

The start caster 7 is a monolith catalyst made of ceramics, and is held in the start caster outer cylinder 17 via a wire net or a ceramic fiber mat 18. Next, the operation of the catalytic converter 1 will be described with reference to FIGS. 19 and 20. After the engine 5 is started, the exhaust gas discharged from each cylinder in the exhaust stroke reaches the catalytic converter 1 via the exhaust manifolds 6a and 6b. The exhaust gas that has reached the catalytic converter 1 collides with the slit portion 4 located on the upstream side of the catalytic converter 1, and in addition to the effect of the slit portion 4 listed below, the slit portion 4 and the outer cylinder 8 are formed by the air layer in the void portion 9. Since and are insulated, the temperature of the slit portion 4 rises fastest.

The formation of the slits reduces the heat capacity of the slit portion 4. Since the cross-sectional area of the metal carrier 40 in the axial direction of the metal carrier 40 is reduced by forming the slit, heat conduction to the downstream side of the metal carrier 40 is suppressed. By staggering the formation positions of the slits, the heat transfer path becomes longer, so that heat conduction to the downstream side of the metal carrier 40 is suppressed.

Since the contact area between the flat plate 2 and the corrugated plate 3 is reduced by forming the slits, heat conduction to the outside of the metal carrier 40 in the radial direction is suppressed. Since the slit has a function of disturbing the flow of exhaust gas, heat transfer efficiency is improved. Further, since the metal carrier 40 and the outer cylinder 8 are joined near the exhaust gas downstream side end portion, and the flange 12 of the outer cylinder 8 and the exhaust pipe and the like are joined near the exhaust gas upstream side end portion, the metal carrier 4
The heat radiation path for heat transmitted from 0 to the exhaust pipe and the like via the outer cylinder 8 becomes long. As a result, the amount of heat released from the metal carrier 40 can be reduced.

Furthermore, since the slit portion 4 is not formed on the exhaust gas downstream side of the metal carrier 40, the thermal conductivity in the radial direction and the axial direction is large and the heat conduction speed is higher than that on the exhaust gas upstream side. Thereby, the temperature of the exhaust gas downstream side of the metal carrier 40 can be quickly raised to the activation temperature of the catalyst substance. Therefore, the entire catalytic converter 1 is heated to a temperature at which the catalytic substance is activated in about 15 to 16 seconds after the engine is started. Then, the exhaust gas flowing into the catalytic converter 1 is activated, purified by the catalytic substance, and discharged from the catalytic converter 1. The temperature of the start caster 7 provided immediately below the catalytic converter 1 is also gradually increased by the high temperature exhaust gas passing through the catalytic converter 1 from the upstream side of the exhaust gas to activate the catalytic substance. Further, when a large flow rate of exhaust gas flows when the engine 5 is under high load, the catalytic converter 1 and the start caster list 7 can purify HC and CO in the exhaust gas by about 80% or more.

According to the method of manufacturing the catalytic converter of this embodiment, since the shaft 23 located at the center of the work has the slit 23a when the flat plate 2 and the corrugated plate 3 are wound,
Workpieces can be easily set and removed. As a result, workability is improved and work man-hours can be reduced, which has an effect of reducing cost. Further, according to the method for manufacturing the catalytic converter of the present embodiment, the material foil 26 is sandwiched and held in the slits 23a, so that the rotation of the shaft 23 is reliably transmitted to the work, and the metal carrier 40 having no looseness is obtained. . Further, by using the wavy shaft 37 on the outer peripheral wall, the rotation of the shaft 37 is surely transmitted to the work, and the metal carrier 40 having no looseness can be obtained.
As a result, the product yield of the metal carrier 40 is improved and the quality is improved.

Further, according to the method of manufacturing the catalytic converter of the present embodiment, since the metal carrier 40 having no looseness is obtained, the accuracy of the welding position detection by the contact type sensor 39 is improved without rattling of the work. Let As a result, the irradiation timing of laser welding becomes accurate, and the product yield of the metal carrier 40 is improved and the quality is improved.

Furthermore, according to the method of manufacturing the catalytic converter of the present embodiment, the contact sensor 39 detects the contact portion between the flat plate 2 and the corrugated plate 3, and the YAG is detected in accordance with this detection signal.
Laser light is emitted from the laser head 34, and the flat plate 2 and the corrugated plate 3 are irradiated.
Since the abutting portion of and is laser-welded, laser welding can be performed while winding the flat plate 2 and the corrugated plate 3 without stopping the rotation of the shaft 23. This allows
It has the effect of improving production efficiency.

[Brief description of drawings]

FIG. 1 is a perspective view of a metal carrier manufacturing apparatus for manufacturing a metal carrier of a catalytic converter according to an embodiment of the present invention.

FIG. 2 is a perspective view of a catalytic converter.

FIG. 3 is a half sectional view of a catalytic converter.

4 is a view on arrow IV in FIG.

FIG. 5 is a development view of a flat plate used for a metal carrier.

FIG. 6 is a schematic explanatory view of a slit portion.

FIG. 7 is a development view showing a first modification of the slit portion formed on the flat plate.

FIG. 8 is a development view showing a modified example 2 of the slit portion formed on the flat plate.

FIG. 9 is a perspective view of a shaft.

FIG. 10 is a development view of a material foil.

FIG. 11 is a perspective view showing a state in which a material foil is fitted in the shaft.

FIG. 12 is a perspective view showing a state in which the material foil is fitted into the shaft at a position biased to the flat plate side.

13 is a perspective view showing a state in which the shaft is rotated 180 ° from the state shown in FIG.

FIG. 14 is a perspective view showing a modified example 3 of the shaft.

FIG. 15 is a perspective view showing a modified example 4 of the shaft.

FIG. 16 is a development view showing a modified example 5 of the material foil.

FIG. 17 is a perspective view showing a modified example 6 of the shaft.

FIG. 18 is a perspective view showing the position of the encoder of the metal carrier manufacturing apparatus.

FIG. 19 is an overall configuration diagram in which a catalytic converter is mounted in an exhaust path of an engine.

20 is a view on arrow XX in FIG.

FIG. 21 is a schematic cross-sectional view showing a state in which the catalytic converter is mounted in the exhaust path of the engine.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Catalytic converter 2 Flat plate 2c Flat plate part 3 Corrugated plate 3c Corrugated plate part 4 Slit part 5 Engine (internal combustion engine) 6a, b Exhaust manifold (exhaust path) 7 Start caster list 8 Outer cylinder 9 Void part 10 Notch part 11, 13 Welding Mark 12 Flange 22 Exhaust pipe 23, 24, 25, 37 Shaft (core material) 23a Slit (gap) 24c, 25c Dividing surface 25a Recess 25b Convex 26, 27 Material foil 27a Hole 30 Metal carrier manufacturing device 31 YAG laser welding Machine 34 YAG laser head 35 Detection gear (gear) 36 Encoder 40 Metal carrier (honeycomb body)

Claims (19)

[Claims] 1. A plurality of slits disposed in an exhaust path of an internal combustion engine and extending in a direction orthogonal to a flow direction of exhaust gas are formed on at least one exhaust upstream side of a flat plate or a corrugated plate made of metal, and the flat plate is provided. A method of manufacturing a catalytic converter comprising a honeycomb body in which the corrugated sheet and the corrugated sheet are alternately stacked and wound around a core material, the core extending along an axial direction including the center of the core material. A step of inserting and fixing a material foil having a flat plate portion and a corrugated plate portion, which is the material of the honeycomb body, in a gap between the materials, and a step of winding the material foil around the core material as an axis. A method of manufacturing a characteristic catalytic converter. 2. The flat plate and the corrugated plate are made of Fe—Cr.
A method of manufacturing a catalytic converter according to claim 1, characterized in that it is made of -Al-REM stainless steel. 3. The core material has a dividing surface divided into two in a plane including the axis thereof, and the flat plate or the corrugated plate is sandwiched and supported by each of the dividing surfaces. Item 3. A method for manufacturing a catalytic converter according to Item 1 or 2. 4. The method for manufacturing a catalytic converter according to claim 1, wherein a part or all of the outer peripheral wall of the core material is formed in a corrugated shape in the circumferential direction. 5. The method of manufacturing a catalytic converter according to claim 1, wherein a part or all of the outer peripheral wall of the core member is formed in a polygonal shape in the circumferential direction. 6. The gap of the core material is defined by the material foil 2
The method for manufacturing a catalytic converter according to any one of claims 1 to 5, wherein the thickness is equal to or less than the thickness of one sheet. 7. The method for manufacturing a catalytic converter according to claim 1, wherein the core material has a diameter of 2 mm to 5 mm. 8. The material foil is composed of the flat plate portion and the corrugated plate portion having a length required to form the one honeycomb body, and the material foil is formed of the flat plate portion and the corrugated plate portion. A method for manufacturing the described catalytic converter. 9. The material foil according to claim 1, wherein the flat plate portion and the corrugated plate portion are bonded to each other.
9. The method for manufacturing the catalytic converter according to claim 8. 10. The material foil, wherein the flat plate portion and the corrugated plate portion are integrally formed.
A method for manufacturing the catalytic converter according to any one of 1. 11. The gap between the core members is less than or equal to the thickness of one sheet of the material foil.
A method for manufacturing the described catalytic converter. 12. The position at which the material foil is fixed to the core member is a boundary portion between the flat plate portion and the corrugated plate portion, according to claim 1. Manufacturing method of catalytic converter. 13. The position where the material foil is fixed to the core material is ½ or more of the outer wall circumference length of the core material in the flat plate portion direction from the boundary portion between the flat plate portion and the corrugated plate portion. The method for manufacturing a catalytic converter according to any one of claims 1 to 11, wherein the positions are separated from each other. 14. The material foil according to claim 1, wherein the flat plate portion and the corrugated plate portion are fixed to the core material without being joined to each other. 2. A method for manufacturing a catalytic converter according to claim 1. 15. The method for manufacturing a catalytic converter according to claim 3, wherein a concave portion or a convex portion is formed on the divided surface of the core material. 16. The method of manufacturing a catalytic converter according to claim 15, wherein the material foil is provided with a hole that can be engaged with the concave portion or the convex portion. 17. The flat plate and the corrugated plate are wound and the contact portion between the flat plate and the corrugated plate is spot-welded or seam-welded by a laser or an electron beam, and the welding position is determined by a contact sensor. It detects, The manufacturing method of the catalytic converter as described in any one of Claims 1-16 characterized by the above-mentioned. 18. The method of manufacturing a catalytic converter according to claim 17, wherein the contact-type sensor detects the welding position by rotation of a gear that meshes with the corrugated plate. 19. A geometrically defined dimensional relationship is provided between the circumferential length of the slits formed in the corrugated plate, the slit pitch of the slits, and the corrugated pitch of the corrugated plate. The method for manufacturing a catalytic converter according to claim 1, wherein the method is not present.