JP2015062911A - Method for manufacturing dissimilar material joint body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a dissimilar material joint body capable of enhancing the joint strength of dissimilar materials to each other regardless of a condition under which the dissimilar materials are joined.SOLUTION: There is provided a method for joining a first material 10 to be joined to a second material 20 to be joined different from the first material 10 in material kind. The method includes: inserting, into the first material 10, a shaft part 2 of a rivet which comprises a material of a kind same as that of the second material 20 and has a head part 3 and the shaft part 2; superimposing the first material 10 installed with the rivet 1, on the second material 20; joining a tip of the rivet 1 to the material 20 by welding; and then forcibly cooling a region B where the first material 10 contacts with the rivet 1.

Description

  The present invention relates to a method for producing a dissimilar material joined body. More specifically, the present invention relates to a technique of a dissimilar material joined body that joins a steel material and a light alloy material or the like and is used as a structure such as an automobile or a railway vehicle.

  In recent years, from the viewpoint of environment and fuel consumption, weight reduction is required for structural members of automobiles, structures for railway vehicles, ships, aircraft, building structures, etc., and aluminum materials, magnesium materials, CFRP, etc. are used. ing. On the other hand, compared to these materials, steel materials are characterized by low cost and good workability, and therefore, development of joints of dissimilar materials combining the two has been performed.

For example, when a dissimilar joint is manufactured using an aluminum material and a steel material, brittle Fe ₂ Al ₅ is formed as a binary intermetallic compound at the interface of the welded portion. In such dissimilar material joining, in order to obtain a structure having high joint strength, it is necessary to suppress the formation of an intermetallic compound having no ductility. Therefore, after the rivet shaft portion of the steel rivet is inserted into a member such as an aluminum material, the tip portion of the shaft portion is brought into contact with the steel material, and the vicinity of the contact portion between the steel materials is welded and joined. Techniques related to are proposed.

  As a method of inserting the shaft portion of the rivet into the aluminum material, etc., the piercing method in which the shaft portion of the rivet is inserted by being pushed into the aluminum material having no hole, or the rivet by previously making a hole in the aluminum material, etc. The pilot hole system etc. which insert the shaft part of this to the hole are mentioned. For example, Patent Documents 1 and 2 disclose a technique in which a steel rivet is caulked and attached to an aluminum material perforated by a piercing method, and the tip of the rivet is spot-welded to the steel material. According to this technique, since a rivet made of the same material and a steel material are joined, it is possible to prevent an intermetallic compound from being formed.

JP 2009-285678 A JP 2010-207898 A

  However, in the techniques described in Patent Documents 1 and 2, in order to increase the bonding strength of the dissimilar material joined body, it is necessary to set in detail the conditions when performing the joining such as welding, which improves the method for manufacturing the dissimilar material joined body. Was demanded.

  Accordingly, the main object of the present invention is to provide a method for producing a dissimilar material joined body capable of increasing the joining strength regardless of the conditions for joining dissimilar materials.

The present invention has been completed as a result of intensive studies by the present inventors in order to solve the above-described problems, and the first material to be joined and the first material to be joined are different from each other in the second kind. When joining a material to be joined, the shaft part of a rivet made of the same kind of material as the second material to be joined and having a head and a shaft part is inserted into the first material to be joined, and the rivet is inserted. A region in which the attached first bonded material and the second bonded material are overlapped, the tip of the rivet and the second bonded material are bonded by welding, and then the first bonded material is in contact with the rivet. The manufacturing method of the dissimilar-material joined body including the process of forcibly cooling is provided.
According to the method for manufacturing the dissimilar material joined body, since the region of the first material to be joined that is in contact with the rivet is forcibly cooled, it is possible to suppress the first material to be softened due to the heat generated by the molten nugget. Here, forced cooling refers to rapidly cooling a region in contact with the rivet of the first material to be bonded to a specific temperature (softening temperature of the first material to be bonded) within a predetermined time.
In the manufacturing method of the dissimilar material bonded body, the first bonded material may have a melting point lower than that of the second bonded material.
The first material to be joined may be a light alloy material, and the second material to be joined may be a steel material.
In this method of manufacturing a joined body of different materials, the first rivet is plastically flowed in the direction of the head of the rivet before the rivet is inserted into the first material to be welded and the welding is performed. A step of caulking the rivet may be included.
Moreover, in this manufacturing method of a dissimilar material joined body, the forced cooling may be performed until the region is at least 600 ° C. or lower.
Furthermore, the welding is resistance spot welding in which the head of the rivet and the second material to be joined are energized. After the welding energization, the electrodes used for the resistance spot welding were energized for 100 msec or longer. The forced cooling may be performed by holding in position.
The forced cooling may be performed by bringing a cooling metal into contact with the head of the rivet or by applying a cooling gas to the first material to be joined.

  ADVANTAGE OF THE INVENTION According to this invention, the joining strength of different materials can be raised irrespective of the conditions at the time of joining different materials.

It is an axial sectional view of the dissimilar material joined body 100 of the embodiment of the present invention. It is a perspective view of the rivet 1 of the dissimilar-materials joined body 100 of the embodiment. It is an axial sectional view of the rivet 1 of the dissimilar material joined body 100 of the embodiment. It is explanatory drawing which shows the manufacturing process of the dissimilar-material joined body 100 of the embodiment. It is a figure explaining the process of forcibly cooling the area | region B of the dissimilar-material joined body 100 of the embodiment. It is a figure explaining the process of forcibly cooling the area | region B of the dissimilar-material joined body 100 of the 1st modification of the embodiment. It is a figure explaining the process of forcibly cooling the area | region B of the dissimilar-material joined body 100 of the 1st modification of the embodiment. It is a figure explaining the process of forcibly cooling the area | region B of the dissimilar-material joined body 100 of the 1st modification of the embodiment. It is a figure explaining the process of forcedly cooling the area | region B of the dissimilar-material joined body 100 of the 2nd modification of the embodiment. It is a figure explaining the process of forcibly cooling the area | region B of the dissimilar-material joined body 100 of the 3rd modification of the embodiment. It is explanatory drawing which shows the manufacturing process of 100 A of dissimilar-material joined bodies at the time of joining by a laser.

  Hereinafter, embodiments for carrying out the present invention will be described in detail. Note that the present invention is not limited to the embodiments described below.

<Dissimilar material joined body 100>
First, the dissimilar material joined body 100 of the embodiment of the present invention will be described. FIG. 1 is a cross-sectional view in the axial direction (direction in which the head 3 is provided with respect to the shaft portion 2) of the dissimilar material joined body 100 of the present embodiment.

  The dissimilar material joined body 100 of this embodiment includes a rivet 1, a first material to be joined 10 through which the shaft portion 2 of the rivet 1 is inserted, and a second material to be joined 20 joined to the shaft portion 2 by welding. In FIG. 1, symbol A indicates a melted part (nugget). In the dissimilar material bonded body 100 of the present embodiment, as will be described later, at the time of manufacture, the region B that is in contact with the rivet 1 of the first material to be bonded 10 is forcibly cooled, and the heat of the melting part A transmitted in the direction of arrow F As a result, the first bonded material 10 is suppressed from being softened. Here, the region B of the first material to be bonded 10 is not particularly limited. Specifically, in the vertical direction of the axial direction, the region of the head 3 from the portion that is in contact with the shaft portion 2 of the first material to be bonded 10. It refers to the area up to the position corresponding to the outer edge.

  In the dissimilar material bonded body 100 of the present embodiment, even when the first bonded material 10 has a lower melting point than the second bonded material 20, the first bonded material 10 is easily softened by the heat of the melted part A. By selectively forcibly cooling the region B in contact with the rivet 1, softening of the first material to be bonded 10 can be prevented and the strength of the dissimilar material bonded body 100 can be improved.

  The first material to be bonded 10 is not particularly limited, but may be a light alloy material. Specifically, aluminum, aluminum alloy (JIS standard 2000 series, 3000 series, 4000 series, 5000 series, 6000 series) System or 7000 system), magnesium, magnesium alloy, and the like. Further, the first bonded material 10 may be CFRP or the like. This 1st to-be-joined material 10 can be used as a plate material, a shape material, a die-cast material, a casting material, or a press molding product of a plate material or an extruded material.

  Moreover, the 2nd to-be-joined material 20 is comprised with a material type different from the 1st to-be-joined material 10, and is comprised with the material of the same kind as the rivet 1 mentioned later. Although it does not specifically limit, For example, the 2nd to-be-joined material 20 can be made into steel materials, Specifically, it can be used as high-tensile steel materials, a galvanized steel plate, stainless steel, etc. The second material to be bonded 20 can be a plate material, a shape material, a casting material, a press-formed product of a plate material, a hot stamp product, or the like.

  From the viewpoint of anticorrosiveness, the first bonded material 10 is overlapped with the second bonded material 20 from the viewpoint of anticorrosive properties, or is applied with an adhesive containing a thermosetting resin, or bonded. A resin tape may be provided. In the dissimilar material bonded body 100 of the present embodiment, as will be described later, the region B in contact with the rivet 1 of the first material to be bonded 10 is forcibly cooled at the time of manufacture, so that this seal, adhesive, adhesive resin tape, etc. Damage due to heat can be prevented.

(Rivet 1)
Next, the rivet 1 constituting the dissimilar material joined body 100 of the present embodiment will be described. FIG. 2A is a perspective view of the dissimilar material joining rivet 1 of the present embodiment. FIG. 2B is an axial sectional view of the rivet 1.

  As shown in FIGS. 2A and 2B, the rivet 1 includes a cylindrical shaft portion 2 and a disk-shaped head portion 3 provided at one end of the shaft portion 2, and the head portion 3 with respect to the shaft portion 2. The cross section in the axial direction (the Z-axis direction in FIG. 2A), which is the direction in which the is provided, has a substantially T-shape. In the rivet 1, the shaft portion 2 is inserted through the first material to be bonded 10, and the tip portion of the shaft portion 2 is bonded to the second material to be bonded 20 by welding. As a result, the dissimilar material joined body 100 in which the first material to be joined 10 and the second material to be joined 20 are joined is manufactured.

  The material of the rivet 1 is made of the same kind of material as that of the second material to be joined 20 in order to suppress the occurrence of brittle intermetallic compounds during spot welding and to prevent the reduction of joint strength. That is, for example, when the second bonded material 20 is a steel material such as SPCC, a galvanized steel plate, or a high-tensile steel plate, the rivet 1 can be a steel material such as mild steel or ordinary steel. Specifically, the rivet 1 is mainly composed of iron and may be appropriately added with alloy elements such as carbon, chromium, nickel, and molybdenum. The rivet 1 may be formed by cutting, but is more preferably forged from the viewpoint of productivity.

  Moreover, although it does not specifically limit, the front-end | tip part of the axial part 2 can be made into the shape which protruded the position close | similar to the center with respect to the outer edge. Furthermore, the corners of the head 3 of the rivet 1 may be chamfered.

  Further, as shown in FIGS. 2A and 2B, an annular groove 31 may be provided around the region of the proximal end portion 21 of the shaft portion 2 on the surface of the head portion 3 that contacts the first bonded material 10. . Since the annular groove 31 is provided in the base end portion 21 of the shaft portion 2 of the rivet 1, the first material to be joined 10 can be plastically flowed into the annular groove 31, and the rivet 1 and the first material to be joined 10 can be flown. The caulking fastening force can be further improved.

  In the rivet 1 of the dissimilar material bonded body 100 of the present embodiment, at least a part of the surface of the head 3 that contacts the first material to be bonded 10 is covered with a film having a higher resistivity than the base material of the second material to be bonded 20. It may be broken. Specifically, the coating includes a rust preventive coating containing zinc, tin and / or aluminum, a polyester resin coating, a coating containing a silicone elastomer, an iron oxide coating (black skin), no Examples thereof include an electrolytic Ni-P plating film and other insulating films.

  When such a coating is covered on the surface of the head 3 that is in contact with the first workpiece 10, the rivet 1 and the second workpiece 20 are joined by welding. It is possible to prevent the welding current flowing through the second material to be bonded 20 from being distributed to the first material to be bonded 10. In this way, current concentrates on the first material to be joined 10 and flows, so that the rivet 1 and the second material to be joined 20 can be efficiently welded.

<Method for Producing Dissimilar Material Joint 100>
Next, the manufacturing method of the dissimilar material joined body 100 of this embodiment is demonstrated. FIG. 3 is an explanatory view showing an example (piercing method) of a manufacturing process of the dissimilar material joined body 100 of the present embodiment.

  First, as shown in FIG. 3 a, the first bonded material 10 is placed on a cylindrical counter punch 300, and the rivet 1 so that the rivet 1 and the counter punch 300 sandwich the first bonded material 10. Is disposed on the first workpiece 10. The rivet 1 can also be arranged, for example, by a cassette-type rivet supply guide (not shown) arranged before and after the pressing process or at a predetermined position of the mold at the time of press molding.

  Next, as shown in FIG. 3 b, when the punch 200 is lowered and the rivet 1 is pushed into the first material to be bonded 10, a part of the first material to be bonded 10 is punched out by the shaft portion 2. The portion 15 falls into the counter punch 300. Thereby, the 1st to-be-joined material 10 is pierced, the axial part 2 is penetrated by the 1st to-be-joined material 10, and the head 3 is located on the surface of the 1st to-be-joined material 10 as shown in FIG. In this state, the tip end surface of the shaft portion 2 is exposed on the lower surface of the first bonded material 10.

  Further, since the rivet 1 is pressed toward the first material to be bonded 10 by the punch 200, the first material to be bonded 10 plastically flows in the direction of the head 3 of the rivet 1, and the rivet 1 is caulked. In particular, when the annular groove 31 is formed in the head 3, the portion sandwiched between the head 3 and the counter punch 300 in the first material to be joined 10 is around the shaft portion 2 of the head 3. It is pushed into the annular groove 31 formed by plastic flow. In this way, as shown in FIG. 3 c, the first material to be joined 10 enters the annular groove 31, and the rivet 1 is caulked and fastened to the first material to be joined 10.

  By adopting such a piercing method, it is possible to improve the accuracy of the position where the rivet 1 is inserted into the first material to be joined 10. Moreover, the shaft diameter of the shaft portion 2 and the hole diameter of the first bonded material 10 can be made substantially the same by punching the first bonded material 10 by the piercing method. Further, the first material to be joined 10 can be plastically flowed in the vicinity of the shaft portion 2 of the rivet 1, and the caulking strength can be improved. And since the 1st to-be-joined material 10 plastically deforms so that the 1st to-be-joined material 10 may flow uniformly to the base end part 21 periphery of the axial part 2 at the time of crimping fastening, in the axial periphery direction Variation in the caulking fastening state is suppressed.

  The caulking and fastening of the rivet 1 to the first material to be joined 10 can also be performed by other methods. For example, the rivet 1 is attached to the first material to be joined 10 that has been previously drilled by adopting a pilot hole method. It may be inserted and caulked and fastened to the first material to be joined 10.

  FIG. 4 shows spot welding of the rivet 1 that is caulked and fastened to the first workpiece 10 and the second workpiece 20 by the process described with reference to FIG. It is a figure explaining the process of forcibly cooling the area | region B which contact | connects the rivet 1 of the joining material 10. FIG.

  First, as shown in FIG. 4a, the rivet 1 that has been caulked and fastened to the first workpiece 10 by spot welding using the electrodes 400 and 500 is overlapped with the first workpiece 10 to form a lap joint. Joined to the second workpiece 20.

  Next, as shown in FIG. 4 b, water W is caused to flow through the water pipe 401 of the electrode 400 and the water pipe 501 of the electrode 500 while the electrodes 400 and 500 are held at the positions where the welding energization is performed. Thereby, the area | region B which contact | connects the rivet of the 1st to-be-joined material 10 is forcedly cooled. Therefore, it is suppressed that the 1st to-be-joined material 10 softens with the heat | fever which generate | occur | produced in the fusion | melting part A. FIG.

  This forced cooling is preferably performed immediately after welding. More preferably, forced cooling is started immediately after welding. That is, it is preferable that water W is allowed to flow through the electrodes from the time of welding, and cooling is started with water W immediately after the end of welding. Thus, by performing forced cooling immediately after welding is performed, softening of the region B of the first workpiece 10 can be more efficiently suppressed.

  Moreover, in order to suppress the softening of the area | region B more stably, it is preferable that the electrodes 400 and 500 are hold | maintained in the position which performed welding energization for 100 msec or more after welding energization.

  In addition, the temperature of the water flowing through the water pipes 401 and 501 is not particularly limited. However, the forced cooling is performed until the region B reaches 600 ° C. or less, so that the softening of the first bonded material 10 can be performed more efficiently. Since it can suppress, it is preferable. The temperature can be measured with a general thermocouple. Specifically, conditions such as welding time and cooling water flow rate are set using a thermocouple, and the region B can be cooled to 600 ° C. or less based on the conditions.

  In the present embodiment, the forced cooling of the region B is described as an example in which water is supplied to the water pipes 401 and 501 provided in the electrodes 400 and 500. However, the present invention is not limited to such an example. The medium may be other than water such as an inert gas.

[First Modification]
FIG. 5 is a diagram for explaining a manufacturing method of the dissimilar material joined body 100 of the first modified example of the present embodiment. In the manufacturing method of the dissimilar material joined body 100 of the present modification example, as described with reference to FIG. 4 a, after welding is performed, the electrodes 400 and 500 are retracted from the dissimilar material joined body 100 and the head of the rivet 1. The cooling metal 600 is installed so that 3 and the 2nd to-be-joined material 20 may be clamped. Then, when water W is caused to flow through the pipe 601 provided in the chiller 600, the region B in contact with the rivet 1 of the first workpiece 10 is forcibly cooled.

  As shown in FIG. 5, two chillers 600 may be pressed against the head 3 of the rivet 1 and the second material to be joined 20, or only one chiller 600 may be pressed against the head 3 of the rivet 1. You may guess. Further, a conventionally known cooling metal 600 can be used and can be appropriately selected so as to correspond to the size of the rivet 1 and the like.

  FIG. 6 is a diagram for explaining another example of the method for manufacturing the dissimilar material joined body 100 of the present modification. As shown in FIG. 6, the cooling metal 610 may have a shape capable of covering the head 3 of the rivet 1. When this chiller 610 is installed on the first workpiece 10 and the rivet 1 and water W is caused to flow through the pipe 611 provided on the chiller 610, both the first workpiece 10 and the rivet 1 are cooled. Is done.

  Moreover, FIG. 7 is a figure explaining the further another example of the manufacturing method of the dissimilar-material joined body 100 of this modification. As shown in FIG. 7, the cooling metal 620 may have a shape that can surround the outer edge of the head 3 of the rivet 1. When this chiller 620 is installed on the first workpiece 10 so as to surround the outer edge of the head 3 of the rivet 1, and the water W flows through the pipe 621 provided in the chiller 620, The bonding material 10 and the outer edge region of the head 3 of the rivet 1 are selectively cooled.

  In this modification, in the forced cooling of the region B, the dissimilar material joining is performed under substantially the same conditions as in the present embodiment except that the cooling metal 600, 610, 620 is used instead of the electrodes 400, 500 described above. The body 100 can be manufactured.

  In the present modification, the region B in contact with the rivet 1 of the first workpiece 10 is forcibly cooled using the chillers 600, 610, and 620. Therefore, by using a chiller having a contact area with the rivet 1 larger than that of the welding electrodes 400 and 500, the region B can be cooled more efficiently than when cooling using only the electrodes. Furthermore, since the electrode used for welding can be immediately moved to the next welding point after completion of the welding process, productivity can also be improved.

[Second Modification]
FIG. 8 is a diagram for explaining a manufacturing method of the dissimilar material joined body 100 of the second modified example of the present embodiment. In the manufacturing method of the dissimilar material joined body 100 of this modification, after welding is performed, the electrodes 400 and 500 are retracted from the dissimilar material joined body 100 and the cooling gas generator 700 is installed. Then, when the cooling gas G is applied to the dissimilar material joined body 100 from the cooling gas generator 700, the region B in contact with the rivet 1 of the first material to be joined 10 is forcibly cooled.

  As long as the cooling gas G is sprayed so as to cool the region B of the first bonded material 10, the installation position and the like of the cooling gas generator 700 are not particularly limited. For example, as shown in FIG. 8, when the first material to be bonded 10 and the second material to be bonded 20 have a plate shape, the first material to be bonded 10 and the rivet with respect to the second material to be bonded 20. It is preferable that the cooling gas G is sprayed from the side where 1 is located.

  A conventionally known cooling gas generator 700 can be used, and can be appropriately selected so as to correspond to the size of the rivet 1 and the like. Furthermore, the conditions such as the air volume of the cooling gas G and the gas temperature are not particularly limited as long as the region B can be forcibly cooled.

  In this modification, in the forced cooling of the region B, the dissimilar material joined body 100 is manufactured under substantially the same conditions as in the present embodiment except that the cooling gas G is used instead of the electrodes 400 and 500 described above. can do.

  In this modification, the region B in contact with the rivet 1 of the first material to be bonded 10 is forcibly cooled by applying the cooling gas G to the dissimilar material bonded body 100, so that the rivet 1 as in the cooling metal 600, 610, 620. Precise alignment with respect to etc. becomes unnecessary.

[Third Modification]
FIG. 9 is a diagram for explaining a manufacturing method of the dissimilar material joined body 100 of the third modified example of the present embodiment. In the manufacturing method of the dissimilar material joined body 100 of this modification, after welding is performed, the electrodes 400 and 500 are retracted from the dissimilar material joined body 100, and the cooling plate 800 is joined to the dissimilar material as shown in FIGS. It is installed on the body 100. Then, by flowing water through the pipe 801 provided on the cooling plate 800, the region B in contact with the rivet of the first bonded material 10 is forcibly cooled.

  A conventionally known cooling plate 800 can be used and can be appropriately selected according to the number and size of the rivets 1 included in the dissimilar material joined body 100.

  In this modified example, in the forced cooling of the region B, the dissimilar material joined body 100 is formed under substantially the same conditions as in the present embodiment except that the cooling plate 800 is used instead of the electrodes 400 and 500 described above. Can be manufactured.

  In this modification, the region B in contact with the rivet 1 of the first bonded material 10 is forcibly cooled by applying the cooling plate 800 to the dissimilar material bonded body 100. Therefore, when welding is performed simultaneously or substantially simultaneously at a plurality of positions by multi-spot welding or the like, the plurality of positions at which welding has been performed can be cooled at a time.

  In the present embodiment and the modification thereof described with reference to FIGS. 1 to 9, the description is focused on an example in which the dissimilar material bonded body 100 is forcibly cooled after spot welding is performed on the rivet 1 and the second bonded material 20. However, it is not limited to such an example. FIG. 10 is a diagram illustrating a case where the head 3A and the shaft portion 2A of the rivet 1A and the second material to be bonded 20A are melted by the laser L, and the first material to be bonded 10 is forcibly cooled after these are bonded. .

  For example, as shown in FIG. 10a, a laser L emitted from a laser oscillator 900 including an optical fiber 901 passes through a magnifying lens 903 and a focus lens 904 in a scanner head 902, and the rivet 1A and the rivet 1A are adjusted by adjusting the angle of the mirror 905. Irradiated to second bonded material 20A. Thus, after welding the rivet 1A including the shaft portion 2A and the head portion 3A and the second material to be joined 20A, as shown in FIG. 10b, for example, the cooling metal 600 is brought into contact with the head portion 3A of the rivet 1A. The forced cooling of the region B can be performed. In the figure, the symbol C indicates a melted portion formed by laser irradiation.

  As described in detail above, in the dissimilar material bonded body 100 of the present embodiment, the region B in contact with the rivet 1 of the first material to be bonded 10 is forcibly cooled, so the first material to be bonded is generated by the heat generated by the molten nugget A. 10 can be softened. Thereby, irrespective of the conditions at the time of joining different materials, the joining strength of different materials can be improved.

DESCRIPTION OF SYMBOLS 1, 1A Rivet 2, 2A Shaft part 3, 3A Head 10 1st to-be-joined material 20, 20A 2nd to-be-joined material 31 Annular groove 100, 100A Dissimilar material joined body 200 Punch 300 Counter punch 400, 500 Electrode 401, 501 Water pipe 600, 610, 620 Cooling metal 601, 611, 621 Water tube 700 Cooling gas generator 800 Cooling plate 801 Water tube 900 Laser oscillator 901 Optical fiber 902 Scanner head 903 Magnifying lens 904 Focus lens 905 Mirror

Claims (8)

When joining the first material to be joined and the second material to be joined having a different material type from the first material to be joined,
Made of the same material as the second material to be joined, the shaft part of a rivet having a head and a shaft part is inserted through the first material to be joined,
After the first material to be joined and the second material to be joined, to which the rivet is attached, are overlapped, and after joining the tip end of the rivet and the second material to be joined by welding,
The manufacturing method of the dissimilar-materials joined body including the process of forcedly cooling the area | region which contact | connects the said rivet of a said 1st to-be-joined material.   The manufacturing method of the dissimilar material joined body according to claim 1, wherein the first material to be bonded has a melting point lower than that of the second material to be bonded. The first bonded material is a light alloy material,
The method for manufacturing a joined body of different materials according to claim 1 or 2, wherein the second material to be joined is a steel material.   4. The method according to claim 1, further comprising: inserting the rivet through the first material to be joined and plastically flowing the first material to be joined and caulking the rivet before performing the joining by welding. The manufacturing method of the dissimilar-material joined body of 1 item | term.   The manufacturing method of the dissimilar-materials joined body of any one of Claims 1-4 which perform the said forced cooling until the said area | region becomes 600 degrees C or less. The welding is resistance spot welding for energizing the head of the rivet and the second material to be joined;
The welding of the dissimilar material joint according to any one of claims 1 to 5, wherein the forced cooling is performed by holding the electrode used for the resistance spot welding at a position where the welding energization is performed for 100 msec or more after the end of the welding energization. Production method.   The manufacturing method of the dissimilar-material joined body of any one of Claims 1-5 which performs the said forced cooling by making a cooling metal contact the said head of the said rivet. The manufacturing method of the dissimilar-materials joined body of any one of Claims 1-5 which perform the said forced cooling by applying cooling gas to a said 1st to-be-joined material.

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