JP2007216250A - Brazed joint structure and its brazing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brazed joint structure, and its brazing method for suppressing the deposition and residual amount of a brazing filler metal in a brazing filler metal feeding hole in joining a plurality of formed bodies. <P>SOLUTION: In a brazed joint structure, a brazing filler metal feeding hole 3 is provided to a first formed body 1. The first forming body 1 and a second forming body 2 are vertically combined with each other so as to close the lower opening end of the brazing filler metal feed hole 3. A solid brazing filler metal 4 inserted in the brazing filler metal feeding hole 3 is melted, and the brazing filler metal is permeated between combined faces 7 to join the forming bodies 1, 2. A brazing filler metal positioning means for positioning the brazing filler metal 4 is provided so as to maintain a predetermined space between the inner wall surface 3a of the brazing filler metal feeding hole 3 and the outer circumferential face 4a of the brazing filler metal 4. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a brazed joint structure in which two or more molded bodies are joined and integrated with a brazing material, and a joining method thereof.

  As a technique relating to the joining of molded bodies, for example, as described in Patent Document 1, a joining method in which a powder molded body is brazed when being sintered is known. In this method, first, a brazing material is filled in the concave portion provided in the first powder compact, and the first powder compact and the second powder compact are combined. Next, when both powder compacts are sintered, the sintering temperature is equal to or higher than the melting point of the brazing material, and the brazing material is melted. Then, the molten brazing material is infiltrated between the combined surfaces, and both powder compacts are joined.

Japanese Patent Publication No.57-44433

  However, in the method described in Patent Document 1, the brazing material melted at the time of sintering adheres and remains on the inner wall surface of the concave portion of the first powder molded body, and as a result, between the combined surfaces. There was a risk that a sufficient amount of brazing material would not permeate, resulting in poor bonding.

  The present invention has been made paying attention to the above technical problem, and has an object of reducing the amount of adhesion and remaining amount of the brazing material in the brazing material supply hole.

  In the brazed joint structure according to claim 1 of the present invention, in order to achieve the above object, a brazing material supply hole is provided in the first molded body, and a lower opening end of the brazing material supply hole is closed. As described above, the first molded body and the second molded body are combined up and down, the solid brazing material inserted into the brazing material supply hole is melted, and the brazing material is infiltrated between the combined surfaces to form both moldings. In the brazed joint structure in which the bodies are joined, the brazing material positioning means for positioning the brazing material so as to maintain a predetermined gap between the inner wall surface of the brazing material supply hole and the outer peripheral surface of the brazing material It is characterized by having.

  According to a second aspect of the present invention, there is provided the brazed joint structure according to the first aspect, wherein the brazing material positioning means guides the brazing material inserted into the brazing material supply hole to a position where the gap can be maintained. It is characterized by including the inclined structure which does.

  The brazed joint structure according to claim 3 is the structure according to claim 2, wherein the inclined structure corresponds to a lower opening end of the brazing material supply hole in the combination surface of the second molded body. It is the inner wall surface of the recessed part provided in this.

  Furthermore, in addition to the structure of claim 3, the brazed joint structure according to claim 4 has a bottom surface smaller than an inner method of the brazing material supply hole and an opening end larger than the inner method. It is characterized by having.

  Furthermore, the brazed joint structure according to claim 5 is the structure according to claim 2, wherein the inclined structure has an inner structure extending from the lower opening end toward the upper opening end. It is a wall surface.

  In the joining method according to claim 6, the first molded body and the second molded body are provided such that a brazing material supply hole is provided in the first molded body and a lower opening end of the brazing material supply hole is closed. In the joining method of joining both molded bodies by melting solid brazing material inserted into the brazing material supply hole and infiltrating the brazing material between the combined surfaces, the brazing material supply hole The brazing material is melted in a state where the brazing material is positioned so as to maintain a predetermined gap between the inner wall surface of the brazing material and the outer peripheral surface of the brazing material.

  According to this invention, the brazing material is maintained at a position where the contact area between the inner wall surface of the brazing material supply hole and the outer peripheral surface of the brazing material is as small as possible, or the two are not in contact with each other. Therefore, the amount of brazing material adhered and remaining in the brazing material supply hole is reduced, and the brazing material can be used efficiently, so that it is possible to suppress poor bonding.

  Next, the present invention will be described based on specific examples. In FIG. 2, a first powder compact (hereinafter abbreviated as “first compact”) 1 and a second powder compact (hereinafter abbreviated as “second compact”) 2 are combined vertically. In addition, the first molded body 1 is provided with a brazing material supply hole 3 for inserting a brazing material as shown in FIG. More specifically, the brazing material supply hole 3 penetrates the first molded body 1 by the same inner method, and is a so-called straight hole. Further, the first molded body 1 and the second molded body 2 are combined in contact with each other so as to close the lower opening end of the brazing material supply hole 3.

  On the other hand, the second molded body 2 is provided with a recess 6 as brazing material positioning means after the brazing material 4 is inserted into the brazing material supply hole 3. The recess 6 is formed in the second molded body 2 at a position corresponding to the lower opening end of the brazing material supply hole 3, that is, a position where the axis of the recess 6 is substantially the same as the axis of the brazing material supply hole 3. Has been. The recess 6 has a bottom surface 5 having a smaller width than the inner method of the brazing material supply hole 3. After the brazing material 4 is inserted into the brazing material supply hole 3, the bottom surface 5 becomes a seating surface on which the brazing material 4 is placed.

  Furthermore, the inner wall surface of the recess 6 is inclined so as to spread from the bottom surface 5 toward the upper opening end. The upper opening end of the recess 6 has a larger width than the inner method of the brazing material supply hole 3 due to this inclination. The inclined surface described here corresponds to the inclined structure of the present invention. The brazing material 4 is guided and positioned by this inclined structure in a direction in which its axis coincides with the axis of the recess 6. As a result, the inner wall surface 3a of the brazing material supply hole 3 and the outer peripheral surface 4a of the brazing material can be maintained in a non-contact state.

  The process of joining the brazed joint structure having the above structure, that is, the method of the present invention will be described in more detail. First, as shown in FIGS. 1 and 2, the first molded body 1 and the second molded body 2 are combined vertically and the brazing material 4 is inserted into the brazing material supply hole 3. At this time, as described above, the brazing material 4 is guided and positioned by the inclined inner wall surface of the recess 6 in a direction in which the axis of the brazing material 4 coincides with the axis of the recess 6. As a result, the inner wall surface 3a of the brazing material supply hole 3 and the outer circumferential surface 4a of the brazing material are maintained in a non-contact state.

  Next, both the molded bodies 1 and 2 are carried into a sintering furnace and sintered at a predetermined temperature. At the time of sintering, the sintering temperature is equal to or higher than the melting point of the brazing material 4, so that the brazing material 4 is melted and the brazing material 4 penetrates between the combined surfaces 7 of the two molded bodies 1 and 2. . Here, since the inner wall surface 3a of the brazing material supply hole 3 and the outer peripheral surface 4a of the brazing material are maintained in a non-contact state, the adhesion and remaining amount of the brazing material to the inner wall surface 3a is reduced and combined. A sufficient amount of brazing material 4 can be infiltrated between the surfaces 7. In this way, the plurality of molded bodies 1 and 2 can be joined simultaneously with the sintering.

  FIG. 3 shows a second embodiment of the present invention. According to FIG. 3, the inner wall surface 3 b of the brazing material supply hole 3 provided in the first molded body 1 is inclined so as to spread from the lower opening end toward the upper opening end. This inclined surface corresponds to the inclined structure in the present invention. After the brazing material 4 is inserted into the brazing material supply hole 3, it is guided to the lower opening end of the brazing material supply hole 3 by this inner wall surface 3b and maintained at that position. At this time, since the inner wall surface 3b of the brazing material supply hole 3 is inclined, a predetermined gap is formed between the inner wall surface 3b of the brazing material supply hole 3 and the outer peripheral surface 4a of the brazing material. Therefore, it has the same effect as the first embodiment.

  In the second embodiment, as described above, the inner wall surface of the brazing material supply hole 3 itself corresponds to the inclined structure or brazing material positioning means of the present invention. Therefore, since the brazing material positioning means which is a characteristic configuration of the present invention can be obtained in the process of forming the brazing material supply hole 3, the process can be simplified.

  In the above example, the case where the molded body to be joined is a powder molded body, but the present invention can be applied to other cases. For example, a metal molded body obtained by casting or forging may be used. Further, the heating for melting the brazing material may be only for melting the brazing material in addition to the heating for sintering the powder compact.

It is detail drawing of the brazing material supply hole in 1st Embodiment of this invention. It is sectional drawing which shows an example of the brazing joining structure of this invention. It is detail drawing of the brazing material supply hole in 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... 1st powder molded object, 2 ... 2nd powder molded object, 3 ... Brazing material supply hole, 3a, 3b ... Inner wall surface (of brazing material supply hole), 4 ... Brazing material, 4a ... (Outside of brazing material) Surface, 5 ... Bottom surface (seat surface), 6 ... Recess, 7 ... Combination surface (of the molded product).

Claims (6)

A brazing material supply hole is provided in the first molded body, and the first molded body and the second molded body are combined vertically so that the lower opening end of the brazing material supply hole is closed. In the brazed joint structure in which both molded bodies are joined by melting the solid brazing material inserted into the brazing material and infiltrating the brazing material between the combined surfaces,
Brazing joining characterized by comprising brazing material positioning means for positioning the brazing material so as to maintain a predetermined gap between the inner wall surface of the brazing material supply hole and the outer peripheral surface of the brazing material Structure.   2. The brazed joint structure according to claim 1, wherein the brazing material positioning unit includes an inclined structure that guides the brazing material inserted into the brazing material supply hole to a position where the gap can be maintained.   3. The brazing according to claim 2, wherein the inclined structure is an inner wall surface of a recess provided at a position corresponding to a lower opening end of the brazing material supply hole in the combination surface of the second molded body. Bonded structure.   4. The brazed joint structure according to claim 3, wherein the recess includes a bottom surface smaller than an inner method of the brazing material supply hole and an opening end larger than the inner method.   3. The brazed joint structure according to claim 2, wherein the inclined structure is an inner wall surface of the brazing material supply hole having a structure that widens from the lower opening end toward the upper opening end. The first molded body is provided with a brazing material supply hole, and the first molded body and the second molded body are combined vertically so as to close the lower opening end of the brazing material supply hole. In the joining method of joining both molded bodies by melting the inserted solid brazing material and infiltrating the brazing material between the combined surfaces,
A joining method comprising melting the brazing material in a state where the brazing material is positioned so as to maintain a predetermined gap between an inner wall surface of the brazing material supply hole and an outer peripheral surface of the brazing material.

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