JP2548796B2 - Brazing method for honeycomb structure - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement in brazing technology in the production of a honeycomb structure that uses metal foil and is assembled by brazing, and particularly relates to a plate fin heat exchanger and The present invention relates to a method of effectively applying a brazing material to a joint portion of a honeycomb structure in the case of manufacturing a metal carrier for purifying exhaust gas of an automobile engine or the like.

(Prior Art) In a manufacturing method such as a radiator or a plate fin type heat exchanger in which flat plates and corrugated plates are alternately layered and brazed to each other, the brazing material is supplied by spraying powdered braze on both sides. It is general that the flat plate and the corrugated plate applied in step 1 are alternately stacked, or the brazing foil is sandwiched between the flat plate and the corrugated plate and stacked.

Further, in the case of a manufacturing process of an exhaust gas purifying metal carrier for manufacturing a cylindrical honeycomb structure (hereinafter referred to as a honeycomb body) by stacking flat foils and corrugated foils and spirally winding them, Japanese Patent Application Laid-Open No. 61-
As known in 199574, after immersing the end face of the honeycomb body in a binder liquid, a brazing material powder is sprayed from the end face,
A method of applying a brazing material is known.

(Problems to be Solved by the Invention) In the conventional brazing material coating method, only in the vicinity of the joining portion formed by the honeycomb body joining portion, that is, the peak portion of the corrugated foil and the flat foil,
It is difficult to uniformly apply a sufficient amount of the brazing material, and the following problems occur.

Since the brazing material is also applied to the portions of the honeycomb body which are not in contact with each other and are not necessary for joining, the amount of brazing material used increases. In addition, since the total amount of the brazing material is large, the components of the brazing material are diffused in the metal foil, and wax corrosion and shrinkage are likely to occur.

That is, as described in the above publication, when the end of the honeycomb body is dipped in the binder liquid, the binder adheres to a portion other than the contact portion between the corrugated foil and the flat foil, that is, the surface of the corrugated foil or the flat wave, and the brazing material also adheres to that portion. Will be attached, and the above-mentioned problems will occur.

When brazing flat plates and corrugated plates alternately in layers, the brazing material is sandwiched between the flat plates and corrugated plates, so the apparent thickness of the honeycomb body is thicker than that and brazing is performed. Before, it is difficult to accurately predict and adjust the thickness after brazing.

When manufacturing a cylindrical honeycomb structure by stacking flat foil and corrugated foil and spirally winding them, it is not possible to drive the gap created after the brazing material is melted by weighting etc. when brazing, The method of sandwiching the brazing material between the flat plate and the corrugated plate cannot be adopted. For this reason, the flat foil and the corrugated foil are overlapped and rolled up in a spiral shape, and then the brazing material must be supplied to the joint portion. In the conventional brazing material supply method, sufficient brazing can be applied only in the vicinity of the joint portion. It was difficult.

In order to accurately supply the wax in the vicinity of the brazing part, there is a dispensing method in which a mixture of a gel binder and a brazing material powder is gradually released from a thin nozzle, but since the nozzle is manually operated, In many cases, it is inefficient to supply to a large number of joining points such as joining, and it is often impossible to approach the nozzle.

INDUSTRIAL APPLICABILITY The present invention provides a simple and inexpensive method for accurately applying a required amount of brazing material only in the vicinity of a brazing site, similarly to the case where the brazing material is carefully applied by the dispensing method. is there.

(Means for Solving the Invention) According to the present invention, a corrugated metal foil (corrugated foil) and a flat metal foil (flat foil) are alternately superposed and wound, or laminated to form a honeycomb body. Then, when fixing the contact portion between the corrugated foil and the flat foil by brazing, the end face of this honeycomb structure, that is, the end face in the axial direction of the honeycomb structure in which the wavy honeycomb surface is exposed is a binder liquid. A method for brazing a honeycomb structure, which comprises contacting the surface of the corrugated foil with a flat foil to suck up a binder, and then spraying a brazing material powder to apply the brazing material to the contacting portion. Is the first invention. A surfactant can be added to the binder liquid to adjust the amount of the binder taken up.

As another method of the present invention, in the case of brazing the contact portion between the corrugated foil and the flat foil forming the honeycomb structure, at a predetermined position, the flat foil coated with a solid or liquid oil and fat is a corrugated foil. A second invention is a method for brazing a honeycomb structure, which is characterized in that a binder and a brazing material powder are supplied to the honeycomb structure which is formed by being rolled up or rolled up in the same manner as in the first invention.

 Hereinafter, the present invention will be described in detail.

In the present invention, the method of supplying the binder to the honeycomb structure is to create a state in which the binder is sucked up by the capillary phenomenon at the contact portion made of the corrugated foil and the flat foil. At the end face of the honeycomb structure, the honeycomb surface formed by the corrugated foil and the flat foil is exposed, and by contacting this surface with the binder surface without immersing it in the binder liquid, the corrugated foil and the flat foil are brought into contact with each other. The binder is sucked up only to the part, and the binder does not adhere to the part other than the contact part.

In a preferred embodiment of the present invention, the end face of the honeycomb structure is placed on a sponge half-soaked in a binder liquid,
Without immersing the honeycomb structure in a binder liquid,
That is, the binder liquid is sucked up to the bonded portion of the honeycomb structure by the capillary phenomenon. After that, a sufficient amount of wax powder is sprayed from the end face of the structure, and the brazing material is applied so that the brazing powder is adhered only to the portion where the binder is adhered.

That is, since there is no gap or a very small gap between the flat foil and the corrugated foil in the portion of the honeycomb structure to be joined, the binder supplied from the binder liquid surface or the sponge rises in the gap due to the capillary phenomenon. This action makes it possible to simultaneously and uniformly attach the binder liquid to a large number of joints at the same time by a simple operation as long as the flatness of the end face of the honeycomb structure is secured. After that, when the wax powder is sprayed from the end of the honeycomb body, the wax particles adhere only to the part where the binder liquid adheres, and as a result, apply the brazing material only to the contact part between the flat foil and the corrugated foil. Can be done.

In addition, in a honeycomb body in which the brazing range is limited to a certain distance from the end face rather than the entire length of the contact portion between the flat foil and the corrugated foil, solid or liquid oil or fat is applied to both sides of the flat foil along the brazing boundary line. After applying it, wrap it up with the wave foil,
After forming the honeycomb structure, the binder liquid is sucked up as described above. The binder liquid sucked up by the capillary phenomenon cannot be further raised because the interfacial tension between the oil and fat portion with the foil is greatly reduced.
As a result, the adhesion range of the binder liquid is limited, and when a brazing material is sprayed on this, a honeycomb body having a limited wax application range can be manufactured.

As the binder liquid used in the present invention, there is, for example, a polyvinyl alcohol solution, in which the surface tension of the binder can be adjusted by adding a surfactant depending on the case, and it is possible to increase the suction strength to the honeycomb structure contact portion. Can be adjusted.

(Examples) Next, examples of the semi-invention will be described with reference to the accompanying drawings.

This example applies the present invention to the production of a metal carrier for an automobile exhaust gas purification catalyst.

Fig. 1 is a diagram showing a step of sucking up a binder into a honeycomb body by utilizing a capillary phenomenon, and Fig. 2 shows a part of the honeycomb body 1 of Fig. 1, in which the binder is attached to the joint part. 2 is a diagram showing a honeycomb body 1 in which flat foil 4 and corrugated foil 5 are overlapped and rolled up in FIG.
After degreasing, as shown in FIG. 1, the end E having an exposed wavy cross section is placed on the sponge 2 half-soaked in the binder liquid 3 to suck up the binder liquid 3. The surface tension of the binder liquid is adjusted with a surfactant in order to secure a sufficient wicking amount and wicking height. As shown in FIG. 2, the binder 6 surely adheres to the joint portion. FIG. 3 is a diagram showing a spraying state of the brazing material. After the binder is sucked up, the brazing material is promptly sprayed as shown in FIG. In this embodiment, as shown in FIG. 3, while the brazing material 8 (powder) is gas-conveyed and sprayed in an elliptical shape by the nozzle 7, the honeycomb body 1 is rotated thereunder to uniformly distribute the brazing material 8 throughout. Attach it. The amount of the brazing material 8 applied can be increased or decreased depending on the amount of the binder attached and the amount of the brazing material sprayed. Therefore, the amount of the binder and the amount of the wax applied are adjusted in advance so that an appropriate amount can be applied. FIG. 4 shows a wax coating state on the honeycomb body 1. In FIG.
4 is a flat foil, 5 is a corrugated foil, and 8 is a powdered brazing material. The honeycomb body 1 on which brazing is finished is dried in a binder solution and then placed in a brazing furnace and heated to complete brazing.

FIG. 5 is a diagram showing a case where the binder suction position is restricted by oil or fat, which is another embodiment of the present invention.

For example, if the fat and oil 9 is applied in a streak shape to the flat foil in advance, and it is wound together with the corrugated foil, and then the honeycomb body is placed on the sponge soaked in the binder liquid 3 as in FIG. As a result, the joint rises, but the fat 9 prevents the binder riser 10 and above from rising. Therefore, as shown in FIG. 3, even if the brazing material is sprinkled, it adheres only to the portion of the binder liquid and does not adhere to other portions, so that the brazing portion can be limited to a specific range.

(Effects of the Invention) According to the present invention, the binder is not applied to unnecessary places, but is applied only to the poles to be joined and limited necessary places. There is no problem such as. Further, it is possible to efficiently and inexpensively manufacture a honeycomb body having excellent strength, in which a large number of joint points are brazed favorably with an appropriate amount of brazing material over the entire length.

[Brief description of drawings]

FIG. 1 is a diagram showing a step of sucking up a binder into a honeycomb body by utilizing a capillary phenomenon. FIG. 2 is a diagram showing a state in which the binder is attached to the bonded portion of the honeycomb body. FIG. 3 is a diagram showing a spraying state of the brazing material. FIG. 4 is a perspective view showing the adhesion state of the wax powder after the wax application. FIG. 5 is a diagram showing a process in the case where the binder suction position is restricted by oil or the like. 1 ... Honeycomb body, 2 ... Sponge, 3 ... Binder liquid, 4 ... Flat foil, 5 ... Corrugated foil, 6 ... Binder, 7 ... Nozzle, 8 ... Wax material, 9 ... Oil, 10 ... Binder Ascending section

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Toji Nakajima, 1 Kimitsu, Kimitsu City, Chiba Prefecture, Nippon Steel Corporation Limited, Kimitsu Works (72) Inventor, Takashi Tanaka, 5-10-1, Fuchinobe, Sagamihara City, Kanagawa Prefecture Nippon Steel Co., Ltd. Second Technology Research Laboratory (72) Inventor Takatoshi Kawasaki 2-6-3 Otemachi, Chiyoda-ku, Tokyo Inside Nippon Steel Co., Ltd. (72) Inventor Shinji Shibata Toyota-cho, Aichi Prefecture Toyota-cho 1 Toyota Motor Corporation (72) Inventor Hikari Aoyagi Toyota Town, Toyota City, Aichi Prefecture 1 Toyota Motor Corporation (72) Inventor Yoshio Nishizawa Marunouchi, Chiyoda-ku, Tokyo 3-3-1 Nippon Metal Co., Ltd. (72) Inventor Akihiko Kasahara 4-10-1 Funawatari, Itabashi-ku, Tokyo, Japan NIPPON Institute of Research, Ltd. (56) Reference JP-A-7-504617 (JP, A) JP-A-56-4373 (J , A) Patent Rights 3-501363 (JP, A) Patent Rights 7-502933 (JP, A) JP Akira 61-199574 (JP, A) U.S. Patent 3479731 (US, A)

Claims (3)

(57) [Claims] 1. A corrugated metal foil (hereinafter referred to as corrugated foil) and a flat metal foil (hereinafter referred to as flat foil) are alternately superposed and wound or laminated to form a honeycomb body, and the corrugated foil is formed. In the case where the contact portion between the flat foil and the flat foil is fixed by brazing, the end face of the honeycomb structure is brought into contact with the binder liquid surface to suck up the binder in the contact portion, and then the brazing material powder is sprinkled to contact the contact portion. A brazing method for a honeycomb structure, characterized in that a brazing material is applied to the honeycomb structure. 2. The method for brazing a honeycomb structure according to claim 1, wherein a surfactant is added to the binder liquid. 3. A flat foil coated with a solid or liquid oil or fat is superposed on a corrugated foil at a predetermined position, and the flat foil is rolled up or laminated to the corrugated foil. Brazing method for honeycomb structure of.