JPH0622519U - Metal carrier - Google Patents

Abstract

(57) [Abstract] [Objective] The present invention has a rigid structure inside the honeycomb body and a flexible structure in the relationship between the honeycomb body and the outer cylinder so that the thermal stress and heat generated by the heating / cooling cycle Prevents the metal honeycomb body from breaking and damaging due to fatigue, etc., and breaking between the outer cylinder and the honeycomb body.
Provided is a metal carrier having excellent durability even in the case of a thin honeycomb body. [Structure] A flat foil and a corrugated foil made of metal are overlapped and wound, and a honeycomb body to be spirally laminated is housed in a metal outer cylinder, and a flat foil-corrugated foil contact portion of the honeycomb body is joined. In the metal carrier, one layer between the outermost periphery of the honeycomb body and the innermost one to four layers is non-bonded except for the vicinity of the upper end portion or the lower end portion thereof, and the other is diffusion bonded,
A metal carrier in which an outer periphery of a honeycomb body and an inner periphery of an outer cylinder are joined within the range of the non-joined portion.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a metal carrier for supporting a catalyst for purifying automobile exhaust gas.

[0002]

[Prior art]

 As a carrier that supports a catalyst for purifying automobile exhaust gas, attention is paid to a metal carrier of a honeycomb body consisting of a heat-resistant stainless steel flat foil (referred to as flat foil) and a corrugated foil (referred to as corrugated foil). Has been done. It is important that these metal carriers not only have heat resistance and oxidation resistance that can withstand high-temperature exhaust gas, but also can withstand the heat cycle of heating and cooling and thermal stress and thermal fatigue due to the temperature distribution difference of the honeycomb body. is there.

As measures against thermal stress and thermal fatigue due to thermal cycles, only the end portions of the foil as disclosed in JP-A-62-273050 and JP-A-62-273051 are axially externally removed. Those that are joined to a cylinder and the flat foil of the honeycomb body is not joined to the corrugated foil, or the flat foil is deformed with a large period as disclosed in Japanese Patent Laid-Open No. 62-83044, There is a method of adding a wave of a small wavelength and giving an extra deformation allowance to the cells of the honeycomb body formed at the bonding points to relax the thermal stress.

In the former method, since the end portion of the foil is joined only to the outer cylinder in the former method, the flat foil and the corrugated foil inside the honeycomb body may be displaced by the high temperature and high speed exhaust gas. It In the latter method, corrugation of the foil is difficult, and at the same time it is difficult to wind the foil, and it is also difficult to join the contacts stably. Therefore, poor bonding of individual cells is likely to occur and the honeycomb structure lacks structural stability.

There is also a method of mechanically fixing the honeycomb body as described in JP-A-62-160728, but since the honeycomb body is separated from the outer cylinder, the honeycomb body vibrates inside the outer cylinder and is supported by the catalyst. Will fall off and the purification capacity will decrease.

On the other hand, attempts have also been made to reduce the thermal stress by improving the joining method of the flat-wave foil of the honeycomb body with the brazing material. That is, a gate structure in which the vicinity of the upper end of the honeycomb body and several layers in the outer peripheral portion are brazed, and a target structure in which the vicinity of the upper and lower ends of the honeycomb body are brazed are proposed. The brazing material is generally expensive and therefore it is preferable to have as few joints as possible, for which the above structures are compatible. However, in a thin honeycomb body with a short length as recently proposed, in the gate structure, the honeycomb structure is deformed into a depression due to lack of synthesis in the axial direction. It is difficult to determine the dozens of structures and dimensions between the honeycomb body and the outer cylinder, and even if the dimensions are forcibly determined, the free length is short and it is close to a rigid structure, and durability is lost.

[0007]

[Problems to be solved by the device]

 In the present invention, the inside of the honeycomb body has a rigid structure and the relationship between the honeycomb body and the outer cylinder is flexible. -The purpose of the present invention is to provide a metal carrier which prevents damage and rupture between the outer cylinder and the honeycomb body and has excellent durability even in the case of a thin honeycomb body.

[0008]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the gist of the present invention is that a flat foil and a corrugated foil made of metal are overlapped and wound, and a honeycomb body formed in a spiral shape is housed in a metal outer cylinder. In the metal carrier formed by joining the flat foil-corrugated foil contact portions, one layer between the outermost periphery of the honeycomb body and the innermost one to four layers except the upper end portion or the lower end portion is excluded. The metal carrier is characterized in that it is joined and the outer circumference of the honeycomb body and the inner circumference of the outer cylinder are joined within the range of the non-joined portion. Further, in the present invention, the flat foil-corrugated foil contact portion of the honeycomb body is diffusion-bonded, and the outer circumference of the honeycomb body and the inner circumference of the outer cylinder are brazed or diffusion-bonded. Is preferred.

As described above, according to the present invention, since the inside of the non-bonding layer of the honeycomb body has a rigid structure and the outer cylinder has a flexible structure, the honeycomb body is sufficiently expanded not only in the radial direction but also in the axial direction. Can relieve stress. Further, since the non-bonding layer is one layer, thermal stress acts on the same layer in a shearing manner and does not act as bending, so that the deformation of the honeycomb body is small.

The present invention will be described in detail below based on the embodiments shown in the drawings. FIG. 1 is a vertical cross-sectional view schematically showing an example of the present invention, in which 1 is a honeycomb body, 2 is an outer cylinder accommodating the honeycomb body 1, and 3 is a non-consolidated body provided in the honeycomb body 1. Reference numeral 4 denotes a joining portion, and 4 denotes a joining portion that joins the inner circumference of the honeycomb body 1 and the outer circumference of the outer cylinder 2.

The honeycomb body 1 is composed of a thin metal flat foil 5 having heat resistance and corrosion resistance and a corrugated foil 6, and the flat foil 5 and the corrugated foil 6 are overlapped as shown in FIG. By applying a weight W to the rear side and applying a back tension to form a spiral shape, the peaks and valleys of the corrugated foil 6 and the flat foil 5 are in close contact with each other. At this time, on the surface (at least the peak portion) of the corrugated foil 6 in the range corresponding to the non-bonding portion 3 of the honeycomb body 1, a bonding inhibitor containing a high melting point oxide is applied by a roll coater device 7 or a brush. Apply by means. Further, it is preferable that the outer peripheral length of the honeycomb body 1 is set to be about 1 to 2% larger than the final dimension. Further, when the outer cylinder is joined by brazing, the brazing is performed within the range of the non-joining portion 3. It is good to attach material.

The outer cylinder 2 is a cylindrical body made of metal having corrosion resistance and heat resistance, and is manufactured by making the circumferential length larger than that of the honeycomb body 1 so that the honeycomb body 1 can be easily inserted into the outer cylinder 2. To do. The outer cylinder 2 in which the honeycomb body 1 is inserted is reduced in diameter by a contracting tube means to be machined to a predetermined size, and at the same time, the honeycomb body 1 is caulked.

The outer cylinder 2 accommodating the honeycomb body 1 in this manner is heated in a vacuum furnace at a temperature of 1100 to 1300 ° C. for 10 minutes to 3 hours, and the flat-wave foil contact portion of the honeycomb body is not heated. The entire structure excluding the contact part is diffusion bonded to form a rigid structure, and at the same time, the outer cylinder-honeycomb body is bonded at a predetermined part.

The non-bonding portion 3 provided in the honeycomb body 1 is composed of 1 to 4 layers (the axial space between the flat foil and the corrugated foil, which is sandwiched between the flat foils and inside) from the outermost periphery 8 of the honeycomb body. It is formed only on one layer. FIG. 2 is an enlarged view of the portion A in FIG. 1, in which the flat and corrugated foil contact portions 9 and 9 are joined to each other from the outer peripheral portion 8, but the non-joined portion 3 is provided on the third layer. In the figure, the flat foil 5 and the corrugated foil 6 of the non-bonded portion 3 are exaggerated for the sake of clarity, but the situation is not limited to such a situation and both foils 5 and 6 are in contact with each other. However, it may be non-bonded. The non-bonded portion 3 is formed by leaving a predetermined length Y in the axial direction from the upper end surface or the lower end surface of the honeycomb body 1. That is, the Y portion is joined in order to prevent it from being deformed by being pushed out by the exhaust gas flow when the entire axial length including the Y portion is made unjoined.

The non-joint portion 3 is provided within four layers from the outer circumference because rapid heating is required in the case of a rigid structure in which the outer cylinder 2 and the honeycomb body 1 are rigidly joined and fixed in the radial direction. Since the thermal stress generated by repeated rapid cooling is concentrated near the outer periphery 8 of the honeycomb body that is joined to the outer cylinder, if the non-joined portion 3 is installed within the four layers that are the concentrated portion, the stress will be increased. This is because it can be alleviated sufficiently. Further, the non-bonded portion 3 has one layer because the thermal stress relaxation ability is sufficient for one layer, and if many layers are provided, the strength of the honeycomb body itself is affected and the durability is deteriorated. Is.

The joint portion 4 between the outer cylinder 2 and the honeycomb body 1 is within the range of the honeycomb body non-joint portion 3 so as not to form a rigid structure in which the outer cylinder 2 and the honeycomb body 1 are integrally joined in the radial direction. Provide the appropriate axial length. By locating the joint portion 4 in this way, the degree of freedom of expansion of the honeycomb body in the radial direction and the axial direction is maintained. The joining method may be either brazing or diffusion bonding. In the case of diffusion bonding, an anti-adhesion agent should be applied to other non-bonding points.

[0017]

[Effects of the Invention] As described above, according to the present invention, the bonding structure capable of relaxing the thermal stress can be manufactured by simple diffusion bonding, and the non-bonding portion is also a single layer, so the number of processing steps and cost can be reduced. . Also, since the metal carrier is almost entirely bonded, even if a misfire etc. occurs in the honeycomb body, the honeycomb body is unlikely to fall off, and even if the honeycomb body is made thin, it has excellent durability. Maintain sex.

[Brief description of drawings]

FIG. 1 is a vertical sectional view schematically showing an example of the present invention.

FIG. 2 is an enlarged explanatory view of a portion A in FIG.

FIG. 3 is an explanatory view showing an example of manufacturing the honeycomb body of the present invention.

[Explanation of symbols]

 1: Honeycomb body 2: Outer cylinder 3: Non-bonded part 4: Bonded part 5: Flat foil 6: Corrugated foil 7: Roll coater device 8: Outer peripheral part 9: Bonded part

Claims (3)

[Scope of utility model registration request] 1. A flat foil and a corrugated foil made of a metal are overlapped and wound,
In a metal carrier obtained by accommodating a spirally laminated honeycomb body in a metal outer cylinder and joining flat foil-corrugated foil contact portions of the honeycomb body, 1 to 4 layers inside the outermost periphery of the honeycomb body A metal characterized in that a portion except for the vicinity of the upper end portion or the vicinity of the lower end portion thereof is not joined to one layer in the space, and the outer circumference of the honeycomb body and the inner circumference of the outer cylinder are joined within the range of the non-joined portion. Carrier. 2. The metal carrier according to claim 1, wherein the flat foil-corrugated foil contact portion of the honeycomb body is diffusion-bonded. 3. The metal carrier according to claim 1, wherein the outer periphery of the honeycomb body and the inner periphery of the outer cylinder are brazed or diffusion bonded.