JP2005081375A - Structure and method for joining different kinds of materials - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure and a method for joining different kinds of materials securing joining strength. <P>SOLUTION: One side of a clad material 3 and a steel material 1 are resistance-welded and joined, and the other side of the clad material 3 and an aluminum material 2 are joined by friction stir joining. The resistance-welding of the aluminum material 2 and the aluminum layer 3b in the clad material 3, which could not yield stable welding in the conventional technique, is thus abandoned, and the joining strength between the aluminum material 2 and the clad material 3 and the joining strength between the steel material 1 and the aluminum material 2 are secured. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a joining structure and joining method of different materials, and more particularly to a joining structure and joining method of different materials in which a clad material is interposed between different materials.

  2. Description of the Related Art Conventionally, bonding of dissimilar materials through a clad material (a composite material obtained by rolling dissimilar materials into a single plate) has been performed. For example, Patent Document 1 describes a dissimilar metal joining method in which a clad material (two-layer clad) of a steel material and an aluminum material is interposed between the steel material and an aluminum material, and the steel material and the aluminum material are resistance-welded. ing. In the dissimilar metal joining method, a nugget is formed between the steel material on the member to be joined side and the steel material on the clad material side, and the steel material on the member to be joined side and the steel material on the clad material side are joined together and the member to be joined A nugget is formed between the aluminum material on the side and the aluminum material on the clad material side, and the aluminum material on the joined member side and the aluminum material on the clad material side are joined together. The aluminum material is joined via the clad material. However, as is generally known, the contact resistance between the aluminum material and the aluminum material is significantly lower than the contact resistance between the steel material and the steel material. It was extremely difficult to perform resistance welding at the same time, and in particular, to form a uniform resistance weld joint (nugget) between the aluminum material and the aluminum material.

Therefore, in the dissimilar metal bonding method, as a pretreatment, after removing the oxide film formed on the aluminum material, the aluminum material is heat-treated to increase the contact resistance on the surface of the aluminum material. A uniform resistance welded joint (nugget) was formed between the two, but there was a new problem that the pretreatment of the aluminum material increased the manufacturing cost. Moreover, since a large-capacity resistance welding machine equipped with a capacitor-type welding power source, an inverter power source, or the like is required, the equipment cost is increased and the power consumption is increased to increase the manufacturing cost. Further, when an alloy of iron and aluminum is generated between the steel material and the aluminum material, the bonding strength is remarkably lowered, so that it is necessary to severely manage the welding current, the electrode, and the like. Moreover, the said dissimilar metal joining method was able to respond | correspond only to the thin plate about 1 mm thick.
Japanese Patent Laid-Open No. 6-63763 (paragraph numbers 0011 to 0014, FIG. 1)

  Therefore, the present invention has been made in view of the above circumstances, and a first object is to provide a joint structure of dissimilar materials in which joint strength is ensured and manufacturing cost is suppressed. In addition, a second object is to provide a method for joining dissimilar materials in which joining strength is ensured and manufacturing cost is suppressed.

In order to achieve the above object, the invention according to claim 1 of the present invention includes a clad material formed by rolling each material into two layers between two members to be joined made of different materials. A joining structure of dissimilar materials in which both members to be joined are joined, and one side of the clad material and one member to be joined are joined, and the other side of the clad material and the other member to be joined are joined. It is characterized by that.
The invention according to claim 2 is the invention according to claim 1, wherein one side of the clad material and the steel material are joined by resistance welding, and the other side of the clad material and the aluminum material are friction stir welded. It is characterized by being joined by any joining means of piercing rivet joining, laser welding, ultrasonic joining and arc welding.
In order to achieve the above object, the invention described in claim 3 of the present invention is a bonding method of different materials used in the bonding structure of different materials described in claim 1 or 2, and is a method of joining a clad material. The side and one member to be joined are joined, and the other side of the clad material and the other member to be joined are joined.
The invention according to claim 4 is the invention according to claim 3, wherein one side of the clad material and the steel material are joined by resistance welding, and the other side of the clad material and the aluminum material are friction stir welded, self-piercing It is characterized by joining by any one of rivet joining, laser welding, ultrasonic joining, and arc welding.

Therefore, according to the first aspect of the present invention, one side of the clad material and one of the members to be joined are joined, and the other side of the clad material and the other of the joined members are joined to each other. The members to be joined are joined through the clad material.
In the invention according to claim 2, one side of the clad material and the steel material are joined by resistance welding, and the other side of the clad material and the aluminum material are joined by friction stir welding, self-piercing rivet joining, laser welding, super welding. The steel material and the aluminum material are joined via a clad material by joining by means of either sonic welding or arc welding.
In the invention according to claim 3, one side of the clad material and one of the members to be joined are joined, and the other side of the clad material and the other member to be joined are joined, so that both the joints made of different materials are joined. Join the members.
In the invention of claim 4, one side of the clad material and the steel material are joined by resistance welding, and the other side of the clad material and the aluminum material are joined by friction stir welding, self-piercing rivet joining, laser welding, ultrasonic joining. The steel material and the aluminum material are joined via the clad material by joining by any joining method of arc welding.

  It is possible to provide a bonding structure of different materials that can secure the bonding strength and suppress the manufacturing cost. In addition, it is possible to provide a bonding method for different materials that can secure bonding strength and suppress manufacturing costs.

  An embodiment of the present invention will be described with reference to FIGS. In this embodiment, a case where a steel material 1 (member to be joined) and an aluminum material 2 (member to be joined) are joined via a clad material 3 will be described with respect to a joining structure and joining method of different materials. As shown in FIGS. 1 and 2, the dissimilar material joining structure is formed by resistance welding the one side of the clad material 3 (the right side in FIG. 1 and FIG. 2 in the drawing) and the joining margin of the steel material 1. At the same time, the other side of the clad material 3 (left side as viewed in FIG. 1 and FIG. 2) and the joining margin of the aluminum material 2 are joined by friction stir welding, and the steel material 1 and the aluminum material 2 are connected via the clad material 3. Be joined. Thereby, the resistance welding of aluminum material x aluminum material whose welding state is likely to vary is abolished, and the joining strength between the steel material 1 and the aluminum material 2 joined through the clad material 3 is ensured.

  As shown in FIG. 1, the clad material 3 used for the joining structure of this dissimilar material is formed in two layers by rolling a steel material and an aluminum material. And the joining structure of this dissimilar material has the joining margin of one side of the said clad material 3 and the steel material 1 so that the steel material layer 3a of the clad material 3 and the steel material 1 (member to be joined) may contact | abut. The aluminum material layer 3b of the clad material 3 and the aluminum material 2 (member to be joined) are brought into contact with each other, and the other side of the clad material 3 and the aluminum material 2 are joined by resistance welding. These are joined together by friction stir welding. As shown in FIG. 2, the dissimilar material joining structure is such that one side of the clad material 3 and the joining margin of the steel material 1 are bonded in a predetermined direction in the extending direction of the joining allowance (up and down direction as viewed in FIG. 2). In addition to resistance welding at intervals, the other side of the clad material 3 and the joining margin of the aluminum material 2 are friction stir welded at a predetermined joining interval in the extending direction of the joining margin.

  Next, a method for joining different materials will be described. First, the other side of the clad material 3 and the joining margin of the aluminum material 2 are overlapped so that the aluminum material layer 3b of the clad material 3 and the aluminum material 2 (member to be joined) are brought into contact with each other. A friction stir tool 4 (see FIG. 3) rotated at a high speed is approached to the overlapped portion from the aluminum material 2 side in the overlapping direction of the aluminum material 2 and the clad material 3 (vertical direction as viewed in the drawing in FIG. 3). Let Then, as shown in FIG. 3, the rotated tool 4 is pushed into a portion where the clad material 3 and the aluminum material 2 are overlapped, and the material around the tool is agitated while being softened by frictional heat generated at that time. . As a result, as shown in FIG. 1, a friction stir welding portion 5 that substantially penetrates the aluminum material layer 3 b of the cladding material 3 and the aluminum material 2 is formed in the portion where the cladding material 3 and the aluminum material 2 are overlapped. The other side of the clad material 3 and the joining margin of the aluminum material 2 are joined. Then, as shown in FIG. 2, the other side of the clad material 3 and the joining margin of the aluminum material 2 are friction stir joined at a predetermined interval in the extending direction of the joining margin.

  Next, as shown in FIG. 4, the joining margin between one side of the clad material 3 and the steel material 1 is set so that the steel layer 3 a of the clad material 3 and the steel material 1 (member to be joined) are brought into contact with each other. Overlaying and applying a welding current between the electrode tips 6 and 7 while pressing the overlapped portions with a pair of electrode tips 6 and 7 of a resistance welder. The welding current to be passed between the electrode tips 6 and 7 is the welding current of the steel material × steel material (the welding current when the steel material 1 and the steel material having the same thickness as the steel layer 3a of the clad material 3 are resistance-welded. ) To 2-30%. As a result, a resistance weld joint 8 (nugget) is formed between the steel material layer 3 a of the clad material 3 and the steel material 1, and the one side of the clad material 3 and the joining margin of the steel material 1 are joined. Then, as shown in FIG. 2, one side of the clad material 3 and the joining margin of the steel material 1 are joined at a predetermined interval in the extending direction of the joining margin. Thereby, the steel material 1 and the aluminum material 2 are joined via the clad material 3.

This embodiment has the following effects.
One side of the clad material 3 and the joining margin of the steel material 1 (member to be joined) are joined by resistance welding, and the other side of the clad material 3 and the joining margin of the aluminum material 2 (member to be joined) are friction stir welded. The steel material 1 and the aluminum material 2 are joined via the clad material 3.
Thereby, resistance welding of the combination of aluminum material x aluminum material is abolished, and resistance welding can be completed with an existing general-purpose resistance welding machine.
Therefore, an expensive resistance welding machine equipped with a large-capacity welding power source becomes unnecessary, and the equipment cost can be reduced. Moreover, the power consumption by resistance welding is reduced, and the manufacturing cost can be reduced. Furthermore, the bonding strength between the steel material 1 and the clad material 3 and the bonding strength between the aluminum material 2 and the clad material 3 are ensured, and as a result, the bonding strength between the steel material 1 and the aluminum material 2 is ensured. be able to. Moreover, after removing the oxide film of the aluminum material 2, which has been performed by the conventional joining method of different materials in which the steel material 1 and the aluminum material 2 are resistance-welded through the clad material 3, the aluminum material 2 is subjected to heat treatment. The pretreatment process to be performed becomes unnecessary, and the manufacturing cost can be reduced. Further, since the aluminum material 2 and the clad material 3 (the aluminum material layer 3b of the clad material 3) are joined by friction stir welding suitable for joining aluminum material × aluminum material, the aluminum material 2 having a relatively thick plate thickness. It is possible to cope with the joining.

In addition, embodiment is not limited above, For example, you may comprise as follows.
Different materials are not limited to the combination of steel and aluminum, and may be combined as necessary.
In the present embodiment, the friction stir welding portion 5 is formed in a spot manner between the joining allowance of the aluminum material 2 and the aluminum material layer 3 b of the clad material 3 to join the aluminum material 2 and the clad material 3. However, the tool 4 is moved in a state in which the rotated tool 4 is pushed between the joining margin of the aluminum material 2 butted against each other and the clad material 3, and as shown in FIG. A friction stir welding portion 5 ′ extending in the joining allowance extending direction (vertical direction in FIG. 2 in FIG. 2) of the aluminum material 2 is formed between the clad material 3 (the aluminum material layer 3 b of the clad material 3) and the aluminum material. 2 and the clad material 3 may be butt-joined. In this case, it is possible to cope with the joining of the aluminum material 2 having a relatively large thickness.
As shown in FIG. 6, the joining allowance of the aluminum material 2 and the clad material 3 may be joined by a self-piercing rivet.
As shown in FIG. 7, the joining allowance of the aluminum material 2 and the aluminum material layer 3b of the clad material 3 may be joined by laser welding.
As shown in FIG. 8, the joining margin of the aluminum material 2 and the aluminum material layer 3b of the clad material 3 may be joined by ultrasonic bonding.
As shown in FIG. 9, a lap joint is formed by the joining allowance of the aluminum material 2 and the clad material 3, and the overlapping portion of the joining allowance of the aluminum material 2 and the aluminum material layer 3b of the clad material 3 is arc welded. You may make it join.
As shown in FIG. 10, a butt joint is formed by the joining allowance of the aluminum material 2 and the clad material 3, and the butt joint between the joining allowance of the aluminum material 2 and the aluminum material layer 3b of the clad material 3 is arc welded. You may make it join.

  FIG. 11 shows an embodiment in which the joint structure of different materials is applied to the body of an automobile. An aluminum extrusion material is used for the rocker member 2 that requires mechanical strength, and the rocker member 2 and the steel floor panel 1 are joined via the clad material 3. In this case, one side of the cladding material 3 and the floor panel 1 are joined by resistance welding, and the other side of the cladding material 3 and the rocker member 2 are joined by a selected joining method.

  FIG. 12 shows an embodiment in which the joint structure of different materials is applied to the body of an automobile. An aluminum extrusion material is used for the rocker member 2 that requires mechanical strength, and a floor panel 3 formed of a clad material is disposed between the rocker member 2 and the steel tunnel member 1, and the floor panel 3 One side and the tunnel member 1 are joined by resistance welding, and the other side of the floor panel 3 and the rocker member 2 are joined by a selected joining method.

It is explanatory drawing of this Embodiment, Comprising: It is sectional drawing which shows the state with which the steel material and the aluminum material were joined via the clad material. It is explanatory drawing of this Embodiment, Comprising: It is a top view which shows the state by which the steel material and the aluminum material were joined via the clad material. It is explanatory drawing of this Embodiment, Comprising: It is a figure which shows the state by which an aluminum material and a clad material are friction-stirred. It is explanatory drawing of this Embodiment, Comprising: It is a figure which shows the state by which steel material and a clad material are resistance-welded. It is explanatory drawing of other embodiment, Comprising: It is a figure which shows the state by which the aluminum material and the clad material were butt-joined by the friction stir welding part extended in the joining allowance extension direction of an aluminum material. It is explanatory drawing of other embodiment, Comprising: It is a figure which shows the state with which the aluminum material and the clad material were joined by the self-piercing rivet. It is explanatory drawing of other embodiment, Comprising: It is a figure which shows the state by which the aluminum material and the clad material were joined by laser welding. It is explanatory drawing of other embodiment, Comprising: It is a figure which shows the state with which the aluminum material and the clad material were joined by ultrasonic bonding. It is explanatory drawing of other embodiment, Comprising: It is a figure which shows the state by which the lap joint formed with the aluminum material and the clad material was joined by arc welding. It is explanatory drawing of other embodiment, Comprising: It is a figure which shows the state in which the butt joint formed with the aluminum material and the clad material was joined by arc welding. 2 is an explanatory diagram of Embodiment 1. FIG. FIG. 6 is an explanatory diagram of Example 2.

Explanation of symbols

1 Steel material (member to be joined), 2 Aluminum material (member to be joined), 3 Clad material

Claims (4)

  A joining structure of dissimilar materials in which both members to be joined are joined via a clad material formed by rolling each material into two layers between two to-be-joined members made of different materials, A joining structure of dissimilar materials, wherein one side and one joined member are joined together, and the other side of the clad material and the other joined member are joined.   One side of the clad material and the steel material are joined by resistance welding, and the other side of the clad material and the aluminum material are any of friction stir welding, self-piercing rivet joining, laser welding, ultrasonic joining, and arc welding. The bonding structure of different materials according to claim 1, wherein bonding is performed by the bonding means.   3. A method for joining different materials used in the joining structure of different materials according to claim 1 or 2, wherein one side of the clad material and one member to be joined are joined, and the other side and the other side of the clad material. A joining method of different materials characterized by joining to a member to be joined. One side of the clad material and the steel material are joined by resistance welding, and the other side of the clad material and the aluminum material are joined by friction stir welding, self-piercing rivet joining, laser welding, ultrasonic joining, or arc welding. The bonding method of different materials according to claim 3, wherein the bonding is performed by a bonding method.

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