JP2620471B2 - Manufacturing method of diffusion bonded metal carrier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a diffusion-bonded metal carrier for supporting a catalyst for purifying automobile exhaust gas.

[0002]

2. Description of the Related Art As a carrier for supporting a catalyst for purifying automobile exhaust gas, a honeycomb body made of heat-resistant stainless steel flat foil (referred to as flat foil) and corrugated foil (referred to as corrugated foil) is used. Metal carriers housed in a heat-resistant metal outer cylinder are being widely used.

[0003] Generally, the flat foil and the corrugated foil constituting the honeycomb body are joined at their contact portions by brazing, but the brazing material is expensive, which increases the carrier cost. In addition, since the area of the brazed portion increases by the amount of the brazing material, the area of the gas passage of the honeycomb body is reduced, causing a problem of pressure loss, and the heat capacity increases by the amount of the brazing material. There is a problem that it takes time to start the engine.

In order to eliminate such a problem, it has been proposed to diffusely bond a flat foil-corrugated foil contact portion as disclosed in, for example, US Pat. No. 4,300,956. . In the case of diffusion bonding, sufficient contact must be made between the previously wound flat foil and corrugated foil. For this reason, Japanese Patent Application Laid-Open No. 2-14747 discloses a method in which an outer cylinder containing a honeycomb body is passed between two rollers and narrowed down (the amount of contraction is 0.5 to 5% of the initial diameter), and then diffusion bonding is performed. Has been disclosed.

[0005]

In order to increase the contact area between the flat foil and the corrugated foil formed by applying an external pressure to the honeycomb body, the contact pressure between the flat foil and the corrugated foil should be increased from the outer periphery of the honeycomb body. It is necessary to ensure that it is raised to the center. However, Japanese Patent Laid-Open No.
As described in JP-A-147747, only the surface pressure of the vicinity of the outer periphery of the honeycomb body is increased only by the contraction of the tube, and the tube does not reach the central portion or remains weak. Therefore, when such a carrier is diffusion-bonded, bonding at the center becomes insufficient, and telescope-like protrusion may occur during practical use.

On the other hand, when the metal carrier is mounted on the engine exhaust system, thermal stress is generated by a rapid thermal cycle of rapid heating and rapid cooling, and in particular, the carrier entirely rigidly joined may be damaged. The invention disclosed in Japanese Patent Application Laid-Open No. 2-14747 is also a whole joint. In order to prevent such breakage due to thermal stress, it is necessary to specify a joint portion and relax the stress. For this reason, in the case of brazing, a binder is applied to a portion to be joined, a brazing material is fixed to the same portion, and a brazing heat treatment is performed. Also, in order to obtain a required bonding structure by providing a part that is not bonded by diffusion bonding,
For example, it is necessary to apply a bonding inhibitor mainly composed of Ti oxide to a portion where diffusion bonding is not performed.

In order to provide a portion where diffusion bonding is not required at the contact portion between the flat foil and the corrugated foil of the honeycomb body, a honeycomb body manufacturing process
That is, it is necessary to apply a bonding inhibitor to a specific portion of the flat foil or corrugated foil during winding, but this causes a problem that productivity is deteriorated and cost of the metal carrier is increased.

The present invention has been made to solve the above-mentioned problems, and a flat foil-corrugated foil is tightly wound at the time of forming a honeycomb body, and an appropriate portion of an outer cylinder containing the honeycomb body is contracted. It is an object of the present invention to provide a method for producing a diffusion-bonded metal carrier that can be selectively joined or not joined.

[0009]

In order to achieve the above object, the present invention provides: (1) a flat foil and a corrugated foil are superposed and spirally wound or laminated;
Insert the formed honeycomb body into the outer cylinder, the axial direction of the outer cylinder
At least one portion of the predetermined portion of the
A method for producing a diffusion-bonded metal carrier, wherein a bonding site of a body is selected . (2) A flat foil and a corrugated foil are superimposed on an outer cylinder provided with a constricted portion in advance, and a honeycomb formed by spirally winding or laminating is inserted, and the shaft of the outer cylinder is inserted. Direction at least one
The flattened portion of the honeycomb body at the portion where the tube was shrunk and the contact density of the corrugated foil was improved, and then the honeycomb body was subjected to a diffusion treatment.
A method for producing a diffusion-bonded metal carrier, wherein a bonding site is selected . (3) A tube having a contracted portion in advance, and an outer cylinder into which a honeycomb body has been inserted, is provided so as to be able to enter and exit the shaping die, and has a stepped convex surface that contacts the outer surface of the outer cylinder and narrows down. Wherein the outer cylinder is reduced in diameter by sliding the segment into a shaping die to apply a surface pressure to at least the honeycomb body at the reduced tube portion.
(2) The method for producing a diffusion-bonded metal carrier according to (2). (4) The outer cylinder into which the honeycomb body is inserted is provided so as to be able to enter and exit the shaping die, and the outer cylinder is held in a segment having a stepped convex surface for holding and narrowing the outer surface of the outer cylinder. (2) the outer cylinder is reduced in diameter by sliding into the pipe, the surface pressure applied to the honeycomb body is adjusted according to the amount of contraction of the constricted portion, and the diffusion bonding range is controlled. Manufacturing method of bonded metal carrier. And (5) how to progress winding on flat foil in the honeycomb body forming line
(1), (2), (1), (2), (3), wherein a corrugated foil is laminated while applying a reverse tension of 1 to 5 kg / cm in a direction opposite to the direction to form a spirally wound and laminated body. 3) or (4) Noi
A method for producing a diffusion bonded metal carrier according to any one of the preceding claims .

[0010]

In order to diffusely bond a honeycomb body having a thickness of about 50 μm, the honeycomb body must be wound tightly to increase the contact surface pressure between the flat foil and the corrugated foil, and then formed after winding. Inserted honeycomb body into outer cylinder, shrink these together,
It is necessary to increase the contact surface pressure near the outer periphery of the honeycomb body. If the amount of tube shrinkage is small, diffusion bonding becomes incomplete. The present invention utilizes this phenomenon, adjusts the amount of contraction in one carrier, separately creates portions that should be diffusion bonded and those that should not, and obtains a metal carrier having a required bonding structure. is there.

Hereinafter, the present invention will be described in detail. FIG. 1 is an explanatory view showing an example of an outline of manufacturing a honeycomb body 1 of the present invention. A flat foil 2 made of a heat-resistant stainless steel or the like is formed by forming a corrugated foil 3 formed by processing a flat foil into a corrugated shape and winding it spirally to form a honeycomb body 1. The flat foil 2 is bitten into a reverse tension applying device 4 such as a bridle roll, and the flat foil 2 is wound while giving a back tension of approximately 1 to 5 kg / cm. Thereby, the contact pressure between the flat foil 2 and the corrugated foil 3 increases. Honeycomb body 1 is flat foil 2
Is wound to the outermost periphery and fixed by spot welding, and then a foil brazing material is welded to a portion to be joined between the outer cylinder and the honeycomb body 1 (for example, near both ends of the carrier or near one end). And so on. No special treatment is performed when the same portion is diffusion-bonded, while a non-diffusion-bonded portion is coated with a bonding inhibitor.

FIG. 2 shows an outline of a contraction device 10 for contracting a metal carrier 9 composed of an outer cylinder 5 into which a honeycomb body 1 is inserted, and includes a forming die 6 and a small segment 7. And a hydraulic cylinder 8 connected to the segment 7 by a piston rod. That is, the segment 7 subdivided by the operation of the hydraulic cylinder 8
Can be moved into and out of the die 6, and the metal carrier 9 is inserted into the open segment 7 by being pushed out of the die 6 as shown in FIG. By being drawn into the die 6, the die 6
Each segment 8 is closed along the inner surface and the diameter of the metal carrier 6 is reduced according to the inner surface shape of the die 7. As shown in FIGS. 3 and 4, the segment 7 is provided with a stepped convex surface 11 at an arbitrary portion of its inner surface. In FIG. 3, a portion 11a corresponding to the upper end portion of the carrier 9 is provided. 9
Are provided at portions 11a and 11b corresponding to the upper and lower ends. The level difference from the concave surface 11c may be determined by the amount of outer tube contraction by the convex surfaces 11a and 11b, and a slight contraction may also be performed on the concave surface 11c at the same time.

In the present invention, the outer cylinder 5 has a preliminary contraction tube portion 5a formed in advance at a position corresponding to a position where the honeycomb body 1 is to be diffusion bonded. FIG. 5 is a partial cross-sectional view showing the contraction of the outer tube 5. The segment 7 and the core 12 having the same outer surface shape as the inner surface of the outer tube 5 to be contracted using the above-described contraction device. By inserting the outer cylinder 5 in between and sliding them into the die 6, for example, as shown in the figure, the diameter of the upper constricted portion 5a of the outer cylinder 5 is reduced by 0.5 mm or more from the other portions. Preform to perform. The preforming in this manner not only ensures the positioning on the segment 7 having the convex portion 11 on the inner surface, but also allows the hydraulic cylinder 8 to simultaneously reduce the diameter of the entire outer cylinder 5 and concentrate the deformation on a part. This is because good molding can be performed. Of course, if such processing can be performed without necessity, a cylindrical outer cylinder without preforming can be used.

After that, as shown in FIG. 6, the honeycomb body 1 is inserted to a predetermined position in the outer cylinder 5. In this case, it is preferable that the outer diameter of the honeycomb body 1 is equal to or slightly smaller than the inner diameter of the outer tube contraction tube portion 5a, so that the honeycomb body 1 can be easily inserted into the outer tube. As shown in FIG. 2B , the outer cylinder 5 containing the honeycomb body 1 is inserted into a segment 7 having an irregular surface 11 corresponding to the outer surface of the outer cylinder, and a hydraulic cylinder 8 is formed as shown in FIG. Is driven to pull the segment 7 into the die 7, and further, the outer cylinder 5 corresponding to the diffusion bonding portion of the honeycomb body 1 is contracted together with the honeycomb body 1. At this time, the diameter of the convex portion formed when the segment is closed is determined by the convex surface forming step provided on the segment 7 and has a step difference equal to the radius difference of the outer cylinder 5 (radius difference between the constricted tube portion and other portions). In this case, the entire outer cylinder can be contracted, and when a step larger than that is provided, there is an effect that the portion of the outer cylinder corresponding to the portion to be diffusion-bonded is further contracted to enhance the joining.

FIG. 7 shows a segment 7 having the shape shown in FIG.
FIG. 8 shows an example of the metal carrier 9 in which each of the segments having the shape shown in FIG. 4 is contracted to form a final contracted portion 5b. In the figure, reference numeral 13 denotes a portion where the honeycomb body 1 is diffusion-bonded,
14 is a brazing part.

As described above, the present invention improves the contact density of the flat-corrugated foil contact portion at a predetermined portion of the honeycomb body by applying back tension and shrinking the tube. By doing so, a uniform and high-density flat-corrugated foil joint can be obtained.

[0017]

EXAMPLE A metal carrier having an outer diameter of 100 mm and a length of 100 mm was manufactured by the following method. The flat foil was made of heat-resistant stainless steel and had a width of 100 mm and a thickness of 50 μm. The corrugated foil was formed by shaping a flat foil into a corrugated shape having a wave height of 1.2 mm and a wave pitch of 2.5 mm. The outer cylinder is made of heat-resistant stainless steel, 1.5 mm thick,
A cylinder having a length of 100 mm and an outer diameter of 101.5 mm (inner diameter of 98.5 mm) was shrunk in the range of 20 mm from the upper end in the longitudinal direction (a portion corresponding to diffusion bonding) by the method of FIG. 1
A constricted tube portion 5a of 00 mm (inner diameter 97 mm) was formed. FIG. 9 shows the outer cylinder shape and dimensions of each part.

The flat foil and the corrugated foil were stacked and wound by the method shown in FIG. 1 to form a honeycomb body. At this time, a back tension of 2.0 kg / cm was applied to the flat foil in a direction opposite to the winding direction. As shown in FIG. 10, when the diameter of the honeycomb body 1 became 97 mm or equivalent, the winding was stopped, and only the flat foil was rotated once, and then the lap portion was fixed by spot welding. After fixing this honeycomb body to a portion to be joined to the outer cylinder on the outer periphery thereof by spot welding of a foil brazing material, and then inserting the same into the outer cylinder, FIG.
The tube was contracted by the tube constriction apparatus shown in FIG. As shown in FIG. 11, when the segment 7 used in the tubing apparatus is drawn into a die, the diameter of the circle formed by the stepped convex surface 11a is 98.5 mm, and the circle formed by the concave surface 11c. The metal carrier after the tube was formed so as to have a diameter of 100 mm, and the outer tube 5 and the honeycomb body 1 were both reduced in diameter by 1.5 mm to a length of 20 mm at the upper end as shown in FIG. The tube portion 5b is formed, and the honeycomb body 1 has a structure having a portion 13 suitable for diffusion bonding. That is, the outer diameter of the outer cylinder in the contracted tube portion 5a is reduced to 98.5 mm and the inner diameter (the outer diameter of the honeycomb body) is reduced to 95.5 mm, and at the same time, the outer diameter of the outer cylinder of the other portion (the portion that contacts the segment concave portion) is also reduced to 100 mm. Although squeezed, this portion of the honeycomb body 1 is not reduced in diameter.

The carrier thus formed is subjected to a vacuum of 1
Heat treatment (diffusion bonding) was performed at 0 ^-4 torr and a temperature of 1250 ° C. for 1 hour. As a result of examining the joining state of the honeycomb body,
The diffusion bonding portion 13 had a good bonding ratio of 90% or more. Also, after supporting the catalyst on this metal carrier, 2000 cc
Mounting of the exhaust system of the engine, the thermal cycle of 800 ° C. and 100 ° C. was added 500 times but at all damage does not occur, it was confirmed that a good bonding state.

[0020]

As described above, in the metal carrier of the present invention, the structure of the carrier to be diffusion-bonded can be separately formed without using a bonding inhibitor or the like, so that the productivity is improved.
A low-cost and durable metal carrier can be produced.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an example of an outline of manufacturing a honeycomb body 1 of the present invention.

FIGS. 2A and 2B show an outline of a contraction device for contracting an outer cylinder or a metal carrier of the present invention, wherein FIG. 2A is a schematic perspective view and FIG.

FIG. 3 is a view showing an example of the segment shape shown in FIG. 2;

FIG. 4 is a view showing another example of the segment shape of FIG. 2;

FIG. 5 is a partially sectional explanatory view showing a state of the outer cylinder pre-contraction tube of the present invention.

FIG. 6 is an explanatory view of inserting the honeycomb body of the present invention into the outer cylinder 5 that has been preliminarily contracted.

FIG. 7 is an explanatory sectional view showing an example of a molded metal carrier of the present invention.

FIG. 8 is an explanatory sectional view showing another example of the molded metal carrier of the present invention.

FIG. 9 is an explanatory sectional view of an outer cylinder of the embodiment of the present invention.

FIG. 10 is an explanatory perspective view of a honeycomb body according to the embodiment of the present invention.

FIG. 11 is an explanatory diagram of a segment according to the embodiment of the present invention.

FIG. 12 is an explanatory view of a metal carrier according to an embodiment of the present invention.

[Explanation of symbols]

 1: Honeycomb body 2: Flat foil 3: Corrugated foil 4: Reverse tension applying device 5: Outer cylinder 5a: Preliminary contraction section 5b: Final contraction section 6: Forming die 7: Segment 8: Hydraulic cylinder 9: Metal carrier 10 : Condenser 11a, 11b: Stepped protrusion 12: Core 13: Diffusion bonding part 14: Brazing

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location F01N 3/28 301 F01N 3/28 311S 311 B01D 53/36 C

Claims (5)

(57) [Claims] 1. A honeycomb body formed by laminating a flat foil and a corrugated foil and winding or laminating them is inserted into an outer cylinder,
At least one tube at a predetermined position in the axial direction of the cylinder
And a method for manufacturing a diffusion bonded metal carrier, wherein a bonding site of a honeycomb body is selected . To 2. A outer tube which previously formed the contraction pipe portion, the flat turning foil and wound corrugated sheet overlapping the spirally or insert the laminated honeycomb body formed by a predetermined in the axial direction of the outer cylinder Fewer parts
After at least one tube is reduced to improve the contact density of the flat foil-corrugated foil of the honeycomb body at the reduced tube portion, a diffusion treatment is performed ,
A method for producing a diffusion-bonded metal carrier, wherein a bonding site of a honeycomb body is selected . 3. A shrinkable tube is provided in advance, and an outer cylinder having a honeycomb body inserted therein is provided so as to be able to enter and exit a shaping die.
The outer surface of the outer cylinder is held in a segment having a stepped convex surface for narrowing down and narrowing, and the outer cylinder is reduced in diameter by sliding the segment into a shaping die. 3. The method for producing a diffusion bonded metal carrier according to claim 2, wherein a surface pressure is applied. 4. An outer cylinder in which a honeycomb body is inserted is provided so as to be able to enter and exit a shaping die, and an outer surface of the outer cylinder is held in contact with the shaping die.
And, it is stored in a segment having a stepped convex surface for narrowing down, the outer cylinder is reduced in diameter by sliding this segment into a shaping die, and the surface pressure applied to the honeycomb body by the amount of contraction of the contraction portion is adjusted. 3. The method according to claim 2, wherein the diffusion bonding range is controlled. 5. In a honeycomb body forming line, a flat foil is formed.
4. A honeycomb body formed by spirally laminating corrugated foils while applying a reverse tension of 1 to 5 kg / cm in a direction opposite to a winding traveling direction. Or 4
The method for producing a diffusion-bonded metal carrier according to any one of the above.