JP2009274090A - Method for manufacturing electric contacter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an electric contacter, capable of highly productively manufacturing an electric contacter having high stability in joining strength between a base metal and a contact point while suppressing the deformation of the base metal. <P>SOLUTION: A rotating tool 22 which rotates at a predetermined speed and moves forward and backward to a jig and in which an end surface of a pushing side has a size not covering the entire surface of a contact point 3 is pushed into a position corresponding to the contact point 3 of a surface opposite to the contact point 3 of the base metal 1 while rotating the rotating tool 22, so that a joining surface between the contact point 3 and the base metal 1 is heated by a friction heat of the rotating tool 22 and the base metal 1 to joint solid phase diffusion bonding or liquid solid diffusion bonding, and then the rotating tool 22 retracts from the base metal 1, thereby manufacturing an electric contacter. As for the rotating tool 22, a pushing operation is repeatedly performed at a plurality of times while shifting the pushing position, alternatively, the position of the rotating tool 22 with respect to the base metal 1 is deviated while maintaining the pushing state when the rotating tool 22 is pushed into. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method of manufacturing an electrical contact used for an electromagnetic switch, an electromagnetic contactor, a circuit breaker, and the like.

  For example, electrical contacts such as electromagnetic switches, magnetic contactors, circuit breakers, etc., can be turned on and off by opening and closing the electrical circuit when the movable contact and fixed contact are contacted and separated. It has been made. Each of these contacts is joined and supported by a movable base metal and a fixed base metal each having a predetermined shape.

  Conventionally, when joining a base metal and a contact, joining by welding, joining by a mechanical means, etc. were performed.

  Examples of the joining by mechanical means include a caulking method and a cladding method. However, in joining by mechanical means, it is difficult to secure a sufficient contact area between the contact and the base metal, so that the current capacity is small. There was a tendency to be limited.

  On the other hand, if it is joining by welding, a sufficient joint area between the contact and the base metal can be secured. For this reason, welding with a large current capacity tends to be used. Examples of the welding method include ultrasonic welding, resistance heating brazing, resistance spot brazing, resistance spot welding, furnace brazing, and high frequency heating brazing. Among these welding methods, ultrasonic welding, resistance spot welding, etc. are generally used for joining relatively small contacts (for example, an area of 5 mm square (vertical 5 mm × horizontal 5 mm)).

  However, in the case of ultrasonic welding, depending on the combination of the material of the contact and the base metal, the bondability between the contact and the base metal may change, resulting in variations in the bonding strength. When the bonding strength between the contact and the base metal varies, the electrical switching life of the contact is affected.

  Further, in resistance spot welding, since a large current is passed in a very short time for joining, there is a problem that the joining strength tends to vary as the joining area increases.

  By the way, in recent years, a joining technique called friction stir welding is being used as a joining method for joining metal members. In friction stir welding, a tool with a pin projecting at the tip is pushed into the joint between the members to be joined while rotating, and the member around the tool is stirred with the pin while heating and softening the member with frictional heat. In this method, plastic flow is generated, and members are joined to each other through this plastic flow.

As an apparatus for performing this kind of friction stir welding, the following Patent Document 1 discloses a joining tool having a pin protruding along an axis at a tip, and a rotation motor for rotating the joining tool around the axis. , A moving motor for moving the welding tool in the axial direction thereof, while the welding tool is rotated by the rotating motor, the welding tool is moved in the axial direction by the moving motor, and the stacked objects to be joined are moved. A pin is pressed against a predetermined joining point, the object to be joined around the pin is heated and softened by frictional heat, the pin is inserted, and the object to be joined near the joining point is agitated with a rotating pin to join the object to be joined. A joining apparatus is disclosed in which, after being integrated at a point, a joining tool is spot-joined at a joining point by pulling out a joining tool along an axis with a moving motor.
JP 2001-314982 A

  In friction stir welding, the members are friction stir to cause plastic flow, so that the plastic flowed members protrude from the joint surface and the appearance is impaired, and attachment to components may be difficult.

  Also, in order to join both members by plastic flow, it is necessary to insert the tip of the tool to the vicinity of the joining surface of both members, so the volume of the object to be joined by the tool tip increases, Deformation in the width direction and build-up in the thickness direction have become conspicuous, and the original assembly allowable accuracy may not be satisfied in component assembly in the subsequent process.

  Furthermore, when the base metal and the contact are to be joined by friction stir welding, if the shape of the base metal is complicated, a rotary tool having a tip diameter that can cover the entire contact junction area to be connected cannot be used. The bonding strength between the contact and the base metal tends to be insufficient. In addition, when a rotating tool having a relatively large tip diameter is used to cover the entire contact surface area to be connected, when the rotating tool is pushed into the base metal, the base metal spreads and becomes larger. There was a possibility that the base metal would be greatly deformed due to frictional heat.

  Accordingly, an object of the present invention is to provide an electrical contact manufacturing method capable of manufacturing an electrical contact having high stability of bonding strength between a base and a contact with high productivity while suppressing deformation of the base. .

  In order to achieve the above object, a first method of manufacturing an electric contact according to the present invention is to support a contact and a base metal by overlapping them with a jig, and the contact on the surface opposite to the contact of the base metal. The rotating tool that rotates at a predetermined speed and moves back and forth with respect to the jig is pushed in at a position corresponding to the above, and the contact and the base metal are brought into contact with each other by frictional heat between the rotary tool and the base metal. A method of manufacturing an electrical contact wherein the rotary tool is retracted from the base metal after solid phase diffusion bonding or liquid phase diffusion bonding is performed, and the end surface on the pushing side covers the entire surface of the contact as the rotary tool In this case, the contact point of the rotating tool is shifted and the pressing operation is repeated a plurality of times, so that substantially the entire surface of the contact is joined to the base metal.

  Further, the second method of manufacturing the electrical contact according to the present invention is to support the contact and the base metal by overlapping them with a jig, at a position corresponding to the contact on the surface opposite to the contact of the base metal. The rotary tool that rotates at a predetermined speed and moves back and forth with respect to the jig is pushed in while being rotated, and the contact and the base metal are bonded by solid phase diffusion bonding or by frictional heat between the rotary tool and the base metal. A method of manufacturing an electrical contact in which the rotary tool is retracted from the base metal after being subjected to liquid phase diffusion bonding, the rotary tool having a size that does not cover the entire surface of the contact as the end surface on the pushing side When the rotary tool is pushed in, the position of the rotary tool with respect to the base metal is shifted while maintaining the pushed state, and the substantially entire surface of the contact is joined to the base metal. To do.

  According to the present invention, the position corresponding to the contact on the surface opposite to the contact of the base metal is pushed in while rotating the rotary tool, and the frictional heat between the rotary tool and the base metal causes the contact between the contact and the base metal. Since the bonding surface is locally heated and bonded by solid phase diffusion bonding or liquid phase diffusion bonding, it is not softened or melted deep inside the base metal, and deformation of the base metal can be minimized. The joining operation can be performed efficiently in a relatively short time. Here, when a metal layer having a low melting point such as a brazing material is not interposed between the base metal and the contact, bonding is performed by solid phase diffusion bonding, and when the metal layer is interposed, bonding is performed by liquid phase diffusion bonding. Is made.

  In the first aspect of the present invention, as the rotary tool, a tool whose end side on the pushing side does not cover the entire surface of the contact is used, and the pushing operation is repeated a plurality of times by shifting the pushing position of the rotating tool. Because almost the entire surface of the contact is joined to the base metal, even if the contact shape is rectangular or complex, the joint by friction rotation does not protrude significantly from the part where the contact and base metal overlap. It can be carried out. As a result, when pressed by the rotating tool, the rolled base metal can be prevented from protruding greatly and protruding outward.

  Further, in the second aspect of the present invention, the rotating tool whose end surface on the pushing side does not cover the entire surface of the contact is used, and the position of the rotating tool with respect to the base metal is shifted while the rotating tool is pushed in. As a result, almost the entire surface of the contact is joined to the base metal, so even if the contact shape is rectangular or complex, the joint by friction rotation does not protrude greatly from the overlapping part of the contact and the base metal. It can be performed. As a result, when pressed by the rotating tool, the rolled base metal can be prevented from protruding greatly and protruding outward.

  The method of manufacturing an electrical contact according to the present invention includes: (1) a brazing material is interposed between the contact and the base metal; and (2) a plating layer is formed on at least one joint surface of the contact and the base metal. And (3) adopting at least one of means for joining an Ag-based plate to the joint surface of the contact, so that a brazing material, a plating layer and an Ag-based material are interposed between the contact and the base metal. It is preferable to perform the joining operation by interposing at least one kind of insert metal selected from a plate. According to this aspect, by interposing the insert metal, the contact and the base metal can be joined in a short time, and the stability of the joining strength is improved.

  According to the present invention, the joining operation of the base metal and the contact can be performed in a short time, and further, the pressed base metal protrudes greatly outward by being pressed by the rotary tool. Since this can be prevented, an electrical contact with good appearance can be produced efficiently.

  The method of manufacturing an electrical contact according to the present invention is intended to manufacture an electrical contact formed by joining a base 1 and a contact 3.

  As shown in FIGS. 1 (a) and 1 (b), the base metal 1 in this embodiment extends in a substantially band shape with a predetermined length, and both side portions 1a and 1a are outward from the intermediate portion 1b. It has a shape that is bent into Contacts 3, 3 are joined to the lower surfaces of both side portions 1a, 1a of the base 1.

  The shape of the contact 3 is not particularly limited, and examples thereof include a square and a rectangle (in this embodiment, a rectangular contact is used).

  The metal material for the base metal 1 and the contact 3 is not particularly limited. For example, as the base metal 1, a metal material that can easily push the rotary tool can be preferably used, and Cu or a Cu-based alloy is preferably exemplified as an example.

  Examples of the contact 3 include materials (Ag-based materials, Ag-oxidized materials, W-based materials, Cd-based materials) shown in Table 1 below.

  In this manufacturing method, the contact 3 and the base metal 1 are overlapped and supported by the jig 50. As shown in FIG. 1A, the jig 50 includes a base portion 51 and a holding portion 55 that is detachably attached to the base portion 51 and presses the base metal 1 against the jig 50. ing. The base 51 has a shape along the base 1 and a holding recess 52 for positioning and holding the base 1 is formed at a predetermined depth. Further, on both sides of the holding recess 52, fitting recesses 53, 53 into which the contact 3 is fitted are formed, respectively. The presser portion 55 has a shape adapted to the upper surface shape of the intermediate portion 1 b of the base metal 1. Then, the contact 3 is fitted in the fitting recess 53 of the base 51, the base 1 is placed on top of it, and the presser 55 is inserted on the upper surface of the intermediate portion 1 b of the base 1. When the base 1 is attached to the base 51 by a fixing means (not shown), the base 1 is pressed so as not to float, and the base 1 and the contact 3 are overlapped and supported.

  As a material of the jig 50, ceramics or stainless steel is preferably used. Since these materials have high heat resistance and low thermal conductivity, frictional heat generated when the tip surface of the rotary tool 22 described later rotates on the base metal 1 is not easily transferred to the jig 50. For this reason, frictional heat can be efficiently transferred to the contact surface between the base metal 1 and the contact 3, and the base 1 and the contact 3 described later can be quickly joined.

  The contacts 3 and the base metal 1 overlapped by the jig 50 are set in, for example, the manufacturing apparatus 10 shown in FIG.

  The manufacturing apparatus 10 will be described with reference to FIG. The manufacturing apparatus 10 includes a stationary platen 12 to which a jig 50 that supports the base metal 1 and the contact 3 in an overlapping manner is fixed, a column portion 14 suspended from the stationary platen 12, and a horizontal movement to the column portion 14. A tool support cylinder 18 supported so as to be horizontally movable and movable up and down via the means 17 and the lifting means 16, and a rotary tool 22 fixed below the tool support cylinder 18 via a fixed chuck 20. Yes. A rotating means 24 is disposed above the tool support cylinder 18, and its rotating shaft is connected to the rotating tool 22 via a fixed chuck 20. Therefore, the rotary tool 22 is moved up and down by the lifting means 16 so as to be movable back and forth with respect to the jig 50, moved in the horizontal direction by the horizontal moving means 17, and further rotated by the rotating means 24 at a predetermined speed. It is configured.

  Referring also to FIG. 3, in the present invention, the rotary tool 22 having such a size that the end surface 30 on the pushing side does not cover the entire surface of the contact 3 is used. That is, the outer diameter D1 of the end surface 30 on the pushing side is smaller than the maximum outer diameter D2 of the contact 3.

  There is no limitation in particular as a front-end | tip shape of the rotary tool 22, For example, what is shown to Fig.4 (a), (b) can be used preferably.

  The rotary tool 22a shown in FIG. 4A has a cylindrical shape with a diameter gradually reduced toward the tip, and the tip surface 30a has a flat circular shape. The rotating tool 22a rotates at a position corresponding to the contact 3 on the surface that is not in contact with the contact 3 of the base 1 so that the frictional heat is generated between the upper surface of the base 1 and the tip surface of the rotary tool 22a. It is made to be pushed into the base metal 1 while generating.

  The rotating tool 22b shown in FIG. 4B has a projection 26 having a smaller diameter than the tip surface 30b protruding at a predetermined height from the center of the flat tip surface 30b. The rotary tool 22b is particularly effective when the thickness of the base metal 1 is large because the protrusions 26 are buried in the base metal 1 to generate frictional heat. If the thickness of the base metal 1 is large, the frictional heat is transferred to the joint surface and the amount of pressing of the rotary tool increases. Therefore, the base metal 1 may be plastically deformed, but the protrusion 26 is provided on the tip surface 30b. As a result, the amount of pressing of the rotary tool can be reduced, so that plastic deformation of the base metal 1 can be suppressed. In this embodiment, the distal end surface 30b and the projection 26 are pushed into and contacted with the base 1, so that the distal end surface 30b forms an “end surface on the pushing side”.

  Next, a first embodiment of the method for manufacturing an electric contact according to the present invention when the manufacturing apparatus 10 is used will be described.

  First, the contact 3 is fitted into the fitting recess 53 of the base part 51. Next, the base metal 1 is inserted and disposed in the holding recess 52. Then, the presser portion 55 is fitted on the upper surface of the intermediate portion 1b of the base metal 1 and is attached to the presser portion 55 on the base portion 51 by a fixing means (not shown). As a result, as shown in FIG. 1, the contact 3 and the base metal 1 are overlapped and supported.

  After the base 1 and the contact 3 in the above state are arranged and fixed at predetermined positions on the stationary platen 12 of the manufacturing apparatus 10, the rotary tool 22 is pushed toward the base 1 while rotating at a predetermined speed. When the tip surface of the rotary tool 22 comes into contact with the base metal 1, frictional heat is generated between the rotary tool 22 and the base metal 1, and further, the rotary tool 22 is pushed in while being rotated, so that FIG. ), The frictional heat is transmitted to the joint surface between the contact 3 and the base metal 1 through the base metal 1, and the joint surface is heated. In this way, high temperature heat and pressure are applied to the contact surface between the base metal 1 and the contact 3, solid phase diffusion bonding is performed at the joint surface between the base metal 1 and the contact 3, and a solid phase diffusion bonding portion is generated. The base metal 1 and the contact 3 are joined to each other through the solid phase diffusion joining portion. Here, solid phase diffusion bonding is one type of diffusion bonding that uses diffusion of atoms, and is a method of bonding in a solid state without melting the bonding surfaces.

  And in this embodiment, as shown in FIGS. 5-7, the rotation tool 22 shifts the pushing position, and repeats pushing operation in multiple times. That is, the rotary tool 22 is pushed into a predetermined position A of the base metal 1 (FIG. 5), and after a predetermined time pressing operation, the rotary tool 22 is retracted from the base metal 1 (see arrow A1 in FIG. 6B). Then, as shown by an arrow A2 in FIG. 6B, the rotary tool 22 is horizontally moved to the unjoined portion, the pushing position to the base metal 1 is shifted, and the rotary tool 22 is moved to the base metal 1 at the position B. The operation of pushing in again (FIG. 7) is performed a plurality of times (in this embodiment, twice) to join the base 1 and the contact 3 together.

  By doing in this way, the electrical contactor with the very small deformation | transformation part 1f of the base 1 as shown to Fig.8 (a)-(c) can be manufactured. FIG. 8A is a plan view of a joint portion between the base 1 and the contact 3, FIG. 8B is a front view of the joint portion, and FIG. 8C is a right side of the joint portion. FIG.

  Here, in FIGS. 14A to 14C, the base 1 and the contact 3 are joined together when the rotary tool 22 is sized so that the end surface on the pushing side covers the entire surface of the contact 3. The schematic block diagram of a part is shown. FIG. 14A is a plan view of a joint portion between the base metal 1 and the contact 3, FIG. 14B is a front view of the joint portion, and FIG. 14C is a right side of the joint portion. FIG. As described above, when the rotating tool 22 has such a size that the end surface on the pushing side covers the entire surface of the contact 3, there are many deformed portions 1f of the base 1, and the deformed portion is inferior in appearance. 1f becomes an obstacle at the time of attachment to a part etc., and attachment workability is impaired.

  Thus, in the present invention, the contact surface between the contact 3 and the base metal 1 is locally heated by the frictional heat between the rotary tool 22 and the base metal 1 to join the contact 3 and the base metal 1 together. The frictional heat is locally generated at the contact portion between the rotary tool 22 and the base metal 1 and efficiently transferred to the joint surface disposed on the opposite surface side, so that the thermal deformation of the base metal 1 is minimized. It is possible to prevent the base metal 1 from dulling and softening the hardness, reduce the energy required for bonding, increase the bonding speed, and improve productivity. Then, as the rotating tool 22, the end surface on the pressing side has a size that does not cover the entire surface of the contact 3, and the pressing operation of the rotating tool 22 is shifted and the pressing operation is repeated a plurality of times. Even when the shape of the contact 3 is a rectangle or a complicated irregular shape, the deformation amount of the base metal 1 is reduced, and joining by frictional rotation can be performed without greatly protruding from the portion where the contact 3 and the base metal 1 overlap. it can.

  2nd embodiment of the manufacturing method of the electrical contact of this invention is described using FIGS. In this embodiment, the rotary tool 22 is pushed into a predetermined position A of the base 1 (FIG. 9), and the position of the rotary tool 22 with respect to the base 1 is shifted while maintaining the pressed state (FIG. 10). Then, the rotary tool 22 is retracted from the base 1 (FIG. 11), and the base 1 and the contact 3 are joined.

  By doing in this way, the electrical contactor with the very small deformation | transformation part 1f of the base 1 as shown to Fig.12 (a)-(c) can be manufactured. FIG. 12A is a plan view of a joint portion between the base 1 and the contact 3, FIG. 12B is a front view of the joint portion, and FIG. 12C is a right side of the joint portion. FIG.

  A third embodiment of the method for manufacturing an electrical contact according to the present invention will be described with reference to FIG.

  In this embodiment, as shown in FIG. 13, with the insert metal M interposed between the contact 3 and the base metal 1, the rotary tool 22 is pushed into the base metal 1 to connect the contact 3 and the base metal 1. Join. By interposing the insert metal M, the contact 3 and the base metal 1 can be efficiently joined in a relatively short time.

Examples of a method for interposing the insert metal M between the contact 3 and the base metal 1 include the following methods.
(1) A method of interposing a brazing material between the contact 3 and the base metal 1 (2) A method of forming a plating layer on at least one joint surface of the contact 3 and the base metal 1 (3) On the joint surface of the contact 3 Method for joining Ag-based plates

  A plurality of these may be used in combination. For example, the system which uses together the insert metal which consists of a plating layer, and the insert metal which consists of a brazing material is mentioned preferably. According to this aspect, since the wettability of the brazing material can be improved by the plating layer, for example, when the insert metal made of the brazing material is partially stacked on the entire insert metal made of the plating layer. Even when the brazing material is melted by the frictional heat of the rotary tool 22, the brazing material flows smoothly over the plating layer and can be spread over the entire joining surface. Work can be performed quickly and stably.

  In the method (1), silver brazing, phosphor copper brazing, or the like can be suitably used as the brazing material. Since these brazing materials are easily melted by frictional heat of the rotary tool 22, the contact 3 and the base metal 1 can be joined to each other by liquid phase diffusion bonding. Here, liquid phase diffusion bonding is one of diffusion bonding that uses atomic diffusion, and is a method in which the bonding surfaces of members to be bonded are temporarily melted and liquefied and bonded in a liquid phase state. It is.

  In the method (2), the plating layer may be a silver plating (eg, silver plating), a gold plating (eg, gold plating), a tin plating (eg, tin plating), or a nickel plating (eg, nickel plating). Nickel phosphor plating), chromium plating (for example, chromium plating), zinc plating (for example, zinc plating, zinc nickel plating), solder plating (for example, tin silver plating, tin lead plating), etc. it can. Each system plating includes each system alloy plating. For example, silver plating includes plating made of a silver alloy containing silver as a main component and other metals. These plating layers may be either not melted or melted by the frictional heat of the rotary tool 22. When a plating layer that does not melt by frictional heat (that is, one having a high melting point) is used, the contact 3 and the base metal 1 can be joined by solid phase diffusion bonding, and the plating layer that melts by frictional heat (that is, has a low melting point). In the case of using a material, the contact 3 and the base metal 1 can be joined by liquid phase diffusion joining.

  In the method (3), examples of the Ag-based plate include Ag and Ag—Cd. Further, as a method of joining the Ag-based plate to the joining surface of the contact 3, it can be joined by a conventionally known joining method, for example, by clad joining or an adhesive. Since the Ag-based plate has a high melting point and does not melt due to frictional heat of the rotary tool 22, when the Ag-based plate is interposed, the Ag-based plate is joined by solid phase diffusion bonding.

The jig | tool used for the manufacturing method of the electrical contact of this invention, the base metal supported by it, and the contact are shown, (a) is rough sectional explanatory drawing in the GG arrow line of (b). , (B) is a plan view. It is a schematic block diagram of the manufacturing apparatus used for the manufacturing method of the electrical contact. It is a related figure of a rotation tool and a contact. It is a schematic block diagram of the front-end | tip shape of a rotary tool. It is a schematic block diagram of 1st embodiment of the manufacturing method of the electrical contact of this invention, Comprising: (a) is a top view, (b) is a front view. It is a schematic block diagram of 1st embodiment of the manufacturing method of the electrical contact of this invention, Comprising: (a) is a top view, (b) is a front view. It is a schematic block diagram of 1st embodiment of the manufacturing method of the electrical contact of this invention, Comprising: (a) is a top view, (b) is a front view. It is a schematic block diagram of the junction part of the contact obtained by the manufacturing method and a base metal, (a) is a top view, (b) is a front view, (c) is a right view. It is a schematic block diagram of 2nd embodiment of the manufacturing method of the electrical contact of this invention, Comprising: (a) is a top view, (b) is a front view. It is a schematic block diagram of 2nd embodiment of the manufacturing method of the electrical contact of this invention, Comprising: (a) is a top view, (b) is a front view. It is a schematic block diagram of 2nd embodiment of the manufacturing method of the electrical contact of this invention, Comprising: (a) is a top view, (b) is a front view. It is a schematic block diagram of the junction part of the contact obtained by the manufacturing method and a base metal, (a) is a top view, (b) is a front view, (c) is a right view. It is a schematic block diagram of the base metal used with 3rd embodiment of the manufacturing method of the electrical contact of this invention. It is a schematic block diagram of the joint part of a base metal and a contact at the time of using the rotary tool of the magnitude | size in which the end surface of a pushing side covers the whole surface of a contact, (a) is a top view, (b) is It is a front view, (c) is a right side view.

Explanation of symbols

1: Base 1a: Side 1b: Intermediate 1f: Deformed part 3: Contact 10: Manufacturing device 12: Fixed platen 14: Column 16: Lifting means 17: Horizontal moving means 18: Tool support cylinder 20: Fixed chuck 22 22a, 22b: Rotating tool 24: Rotating means 26: Protrusion 50: Jig 51: Base 52: Holding recess 53: Fitting recess 55: Pressing portion

Claims (3)

Rotating at a predetermined speed and rotating back and forth with respect to the jig at a position corresponding to the contact on the surface of the metal plate opposite to the contact. The tool is pushed in while rotating, and the contact and the base metal are solid phase diffusion bonded or liquid phase diffusion bonded by frictional heat between the rotary tool and the base metal, and then the rotary tool is removed from the base metal. A method of manufacturing a retracted electrical contact comprising:
As the rotating tool, use a tool whose size is such that the end surface on the pushing side does not cover the entire surface of the contact,
A method for producing an electrical contact, wherein the pushing position of the rotating tool is shifted and the pushing operation is repeated a plurality of times, so that substantially the entire surface of the contact is joined to the base metal. Rotating at a predetermined speed and rotating back and forth with respect to the jig at a position corresponding to the contact on the surface of the metal plate opposite to the contact. The tool is pushed in while rotating, and the contact and the base metal are solid phase diffusion bonded or liquid phase diffusion bonded by frictional heat between the rotary tool and the base metal, and then the rotary tool is removed from the base metal. A method of manufacturing a retracted electrical contact comprising:
As the rotating tool, use a tool whose size is such that the end surface on the pushing side does not cover the entire surface of the contact,
When the rotary tool is pushed in, while maintaining the pushed state, the contact of the rotary tool with respect to the base metal is shifted to join substantially the entire surface of the contact to the base metal. Child manufacturing method.   (1) A brazing material is interposed between the contact and the base metal, (2) a plating layer is formed on at least one joint surface of the contact and the base metal, and (3) a joint surface of the contact By adopting at least one of means for joining an Ag-based plate to at least one kind of insert metal selected from a brazing material, a plating layer and an Ag-based plate between the contact and the base metal The method for manufacturing an electrical contact according to claim 1, wherein the joining operation is performed with a gap interposed therebetween.