JPH04141239A - Preparation of oval metal carrier - Google Patents

Abstract

PURPOSE:To stably and simply obtain an oval metal carrier by winding a flat plate and a corrugated plate around a core body a predetermined number of times and subsequently pulling out the core body to form a space part and pressing the space part from the outside by the flat plate to collapse the same to form an oval honeycomb body and receiving the honey comb body in an outer cylinder. CONSTITUTION:When a flat plate 6 and a corrugated plate 7 are superposed one upon another to be wound, an oval core body 5 wherein the radius R1 of curvature of the long diameter end thereof is taken as large as possible so that the flat plate and the corrugated plate are not bitten in the long diameter ends 5a, 5a' of the oval core body is used to prepare a honeycomb molded body 8 having an oval shape along the core body. The honeycomb molded body 8 having a space 9 is pressed from above and below on the short diameter side of the core body and introduced into an outer cylinder 9 under pressure in such a state that the space 9 is collapsed to be received therein as a honeycomb body 11 wherein the space 9 is collapsed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing a metal carrier, particularly an elliptical metal carrier, supporting a catalyst for purifying engine exhaust gas from automobiles and the like.

(Prior art) Conventionally, carriers with a structure in which precious metal catalysts such as platinum are supported on ceramic honeycombs such as cordiolite have been used to purify exhaust gas from automobile engines, etc., but recently metal carriers have been attracting attention as an alternative to this. and has already been put into practical use.

This metal carrier is generally made of a cylindrical honeycomb formed by winding or laminating a heat-resistant stainless steel flat plate (foil) with a thickness of around 50 gm and a corrugated corrugated plate (foil). It is manufactured by forming a body, inserting it into a heat-resistant stainless steel outer tube, and then joining the flat plate, corrugated plate, and outer tube by brazing or resistance welding.

The metal carrier mentioned above is not only cylindrical but also has an elliptical shape depending on the exhaust gas system due to the space available for the exhaust pipe.

It is relatively easy to overlap a flat foil and a corrugated foil and wind them in a perfect circular spiral shape, but it is difficult to wind them in an elliptical shape. In other words, in the case of a perfectly circular honeycomb body, it is sufficient to wind the flat foil and the corrugated foil while applying the same tension, but in the case of an ellipse, the tension is applied differently in the axial direction, and the tension is applied in the long axis direction. Since the curvature of the turn on the long axis is much smaller than that on the short axis, a large tension is required to prevent the turn on the long axis from bending. Also, if the tension is increased more than necessary, the honeycomb structure will collapse.

However, elliptical metal carriers can be made not only by overlapping flat plates and corrugated plates to form a spiral shape, but also by
Other methods are known, as disclosed in Japanese Patent No. 6 and Japanese Utility Model Publication No. 180621/1983.

In other words, in the former, half-shell bodies are placed above and below, which are obtained by dividing an elliptical outer shell (outer cylinder) into halves, and a honeycomb body wound into a cylindrical shape with a cylindrical space in the center is sandwiched between the half-shell bodies. in,
It is proposed that an elliptical metal carrier be made by pressing from above and below and butting and joining the half shells. However, according to this method, the axis of the original circular honeycomb body is reduced (short axis side) and expanded (long axis side), so the flat plate and corrugated plate that make up the honeycomb are separated on the long sleeve side. On the short axis side, the corrugated plate in particular tends to be compressed and the cell structure deforms, causing problems with joint strength and the effect of local changes in pressure drop on gas flow. Furthermore, as is clear from the drawings in the above-mentioned publication, the carrier is racetrack-shaped and does not form an elliptical shape without straight parts.

The latter (Japanese Utility Model Application Publication No. 180621/1983) forms a honeycomb body with an elliptical cross section by laminating flat plates and corrugated plates, and at this time, a honeycomb body is formed by laminating a flat plate and a corrugated plate. A carrier structure is created by placing a deformation prevention plate with the same engraving coefficient as the shell and welding it to the two divided shells, or by storing a laminated honeycomb body in the split shell body or by providing a deformation prevention plate. As a result, the structure becomes complicated and productivity is poor.

In order to obtain a non-circular metal carrier such as an ellipse having a cell structure, the present inventors formed a core by laminating a corrugated plate and a flat plate, and further layered a corrugated plate and a flat plate on the core. A method of overlapping and spirally winding was proposed in Japanese Patent Application No. 1-338912. However, this method is also time-consuming because it uses lamination means to form the core, so it is desired to further simplify the manufacturing process.

Furthermore, a corrugated plate and a flat plate are stacked on a flat rectangular core plate and wound into a flat spiral shape, and when a predetermined number of winding layers are formed, the core plate is removed and the honeycomb-shaped formed body is placed inside an elliptical outer cylinder. There is also a method of manufacturing an elliptical carrier by press-fitting the carrier, but when winding a flat plate and a corrugated plate around a flat core plate, the winding rotation of the flat plate and corrugated plate at one width end of the flat core plate is as shown in Fig. 5. Since the radius of curvature is small in the rotating part, the phenomenon 2 of digging in of flat plates and corrugated plates occurs over several layers. Moreover, since the several layers where the biting occurs are unstable, the finished dimensions in the major axis direction and minor axis direction are not constant, and as shown in Fig. 6, in the parallel part 3 of the core body, the flat plate and the corrugated plate and rises due to its elasticity, causing 4.
A problem arises in that the shape becomes unstable.

(Problem to be solved by the invention) In order to manufacture an elliptical metal carrier as described above,
Various methods have been tried, but none of them has resulted in a stable product. In the present invention, the side layering of the core body itself is the same as the conventional method, but by devising the shape of the core body and using simple equipment, it is possible to extremely stably form a predetermined oval metal carrier into parts. The purpose is to obtain.

(Means for Solving the Problems) In order to achieve the above object, the present invention has the following configuration. In other words, (1) When manufacturing an elliptical honeycomb body by crushing a formed body in which a flat plate and a corrugated plate are wound spirally around a core, the flat plate and corrugated plate wound around the long diameter end are Using an elliptical core body with a radius of curvature that does not cause digging, a flat plate and a corrugated plate that are wound around the short diameter end, and a radius of curvature that allows these to come into close contact with the core body, the flat plate is rolled along the core body. After winding a predetermined layer of corrugated sheets, the core body is pulled out, and the formed space is pressed from the outside with a flat plate to be crimped to form an elliptical honeycomb body, and the honeycomb body is housed in an outer cylinder. A method for manufacturing an oval metal carrier, characterized by:

(2) The method for producing an elliptical metal carrier as described in the preceding item, wherein the core body is a solid body or a hollow body.

(3) A method for manufacturing an elliptical metal carrier, which uses a hollow core and is characterized by pressing the honeycomb forming body and then pulling out the core.

The present invention will be explained in detail below.

Figure 111 shows the core material 5 for manufacturing the honeycomb body of the present invention.
shows. That is, the core material 5 is a hollow cylinder or a solid cylinder with an elliptical cross section, and a flat plate 6 and a corrugated plate 7 are overlapped and rolled along the outer surface of the core material 5 as shown in FIG. During this winding, the long diameter ends 5a, 5a of the flat plate and corrugated plate are of the elliptical core body.
It is necessary to make the radius of curvature R1 of the major diameter end of the core body as large as possible so as not to cut into =. If the radius of curvature R1 is small, the corrugated plate falls into the pitch, resulting in the planar-corrugated plate losing its shape and being in close contact with each other as shown in FIG. In particular, when winding a flat or corrugated sheet, it is done while applying pack tension, and the wave pitch of the corrugated sheet tends to increase the amount of tension at the long diameter ends 5a, 5a- of the corrugated sheet, so that it tends to spread out. The angle of fall (wave pitch) also tends to become large. Therefore, the radius of curvature R1 of the core material should be at least twice the wave pitch.

In addition, if the shorter diameter sides 5b, 5b- are flat, the raised portion 4 is likely to be formed as shown in FIG. It is made to adhere closely to the core material without breaking.

As described above, the present invention uses the elliptical core body 5 having the radius of curvature R, R2 as large as possible at the major axis end and minor axis side when winding the flat plate 6 and the corrugated plate 7 while overlapping each other. Accordingly, an elliptical honeycomb formed body 8 along the core can be manufactured.

FIG. 3 shows a honeycomb molded body 8 formed by winding a predetermined number of layers of flat plate and corrugated plate, with the elliptical core body 5 being pulled out, and a cylindrical space 9 is formed after the elliptical core body 5 is pulled out. ing. The elliptical core body 5 has flexibility to the extent that it can be easily punched out if it is made into a hollow body made of a cylindrical plate. Furthermore, if it is a solid rigid body, it can be easily pulled out by applying a lubricant to the surface.

The honeycomb molded body 8 having a space 9 is pressed from above and below (arrows) on the short diameter side, and with the space 9 crushed, it is press-fitted into an outer cylinder 10 formed into a predetermined elliptical shape as shown in FIG. and is housed in an outer cylinder 10 as a honeycomb body 11 with spaces 9 in close contact with each other. Honeycomb formed body 8 before being stored in the outer cylinder 10
has an oblate elliptical shape formed along the core material 5, and even when housed in the outer cylinder, there is little misalignment between the flat plate and the corrugated plate making up the honeycomb body 11, and the shape is stable. keeping. The space 9 is brought into close contact with the molded body 8 by applying pressure with a flat plate from above and below the molded body 8 to bring it into close contact with the molded body 8 as described above. In addition to the method of press-fitting the molded body 8 into the outer cylinder 1,
A method may also be adopted in which the outer cylinder is compressed after being stored at zero.

The honeycomb body of the present invention is produced by joining a predetermined portion of the flat plate-corrugated plate contact portion of the honeycomb body using a known method, or joining the outer cylinder and the honeycomb body by brazing or other means.
Furthermore, a catalyst is supported on the product.

(Example) An ellipse made of a mild steel plate with a thickness of 1 cm, the major axis length is 78 m, the minor axis length is 18 mm, the radius of curvature R3 at the major axis end is 5 m, and the radius of curvature R2 at the minor axis side is 150 m. A hollow core material is formed, and a heat-resistant Cr-A7
A 50 #l thick flat plate made of alloy steel and a corrugated plate were stacked together and wound spirally along the outer part of the core material while being pulled with a rear tension of 6 kg to create a honeycomb formed body. After pulling out the core, pressurize the formed body from above and below on the minor axis side using a jig, and press the formed central space to create a shape with a major axis of 17,518 mm and a minor axis of 90 mm.
+am, a honeycomb body with a length of 120 m was formed. This honeycomb body was press-fitted into a stainless steel outer cylinder having a thickness of 2 cm and whose inner periphery was slightly smaller than each dimension of the honeycomb body, and the space that the honeycomb molded body had was completely sealed.

The cell structure of the honeycomb body (through holes formed by a flat plate and a corrugated plate) was stable with almost no displacement. After that, the honeycomb body and the honeycomb body and the outer cylinder were joined by brazing using the usual method, and when a durability test was conducted with heating at 850℃ and cooling at 150℃ for 15 minutes per cycle, there was no problem even after 300 hours. was not seen.

(Effects of the Invention) As explained above, according to the method of the present invention, an elliptical metal carrier with excellent dimensional accuracy can be obtained.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an example of the core material of the present invention, FIGS. 2 to 4 are diagrams illustrating an example of the manufacturing process of the present invention, and FIG. , FIG. 3 shows the state when the molding is completed, FIG. 4 shows the situation when the product is stored in the outer cylinder, and FIGS. 5 and 6 show the conventional defect situation. 1; flat core plate 2: biting part 3, flat part; raised part, ni- material; flat plate; corrugated plate 8; honeycomb formed body; space 10; outer cylinder 11; honeycomb body Applicant Nippon Steel Corporation Company sub-agent

Claims (3)

[Claims] (1) When manufacturing an elliptical honeycomb body by crushing a molded body in which a flat plate and a corrugated plate are piled up around a core and wound spirally, the flat plate and corrugated plate wound around the long diameter end may bite into each other. A flat plate and a corrugated plate are wound around each other at their short diameter ends, and an elliptical core body has a radius of curvature such that the core body is in close contact with the flat plate and the corrugated plate. After winding a predetermined layer of the core body, the core body is pulled out, the formed space is pressed from the outside with a flat plate, and crimped to form an elliptical honeycomb body, and the honeycomb body is housed in an outer cylinder. A method for manufacturing an oval metal carrier. (2) The method for manufacturing an elliptical metal carrier according to claim 1, wherein the core body is a solid body or a hollow body. (3) A method for manufacturing an elliptical metal carrier, which uses a hollow core and is characterized by pressing the honeycomb forming body and then pulling out the core.