JP2006096276A - Work joining method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a work joining method capable of suppressing the equipment cost to be low at each production base when a small-lot production of cars is performed in many production bases. <P>SOLUTION: The work joining method comprises an assembly step of assembling works A-G in a predetermined assembly state at one production base when performing a small-lot production at overseas production bases or the like, a temporary fitting step of temporarily fitting works assembled to each other in a predetermined assembly state in the assembly step by the spot welding, a work separating step of separating the works by releasing the joining by the spot welding while opening assembly holes in a spot welded part S formed in the temporary fitting step, and a permanently joining step of permanently joining the works with each other by positioning the works in a predetermined assembly state by transporting each work to each production base in this state, and utilizing the assembly holes at each production base. An assembly tool can be omitted or simplified at each production base, and the equipment cost can be suppressed to be low. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a workpiece joining method for joining a plurality of workpieces in a predetermined assembly state.

  When joining a plurality of workpieces in a predetermined assembly state, as described in Japanese Patent Application Laid-Open No. 2003-146262 and Japanese Patent Application Laid-Open No. 9-123961, the workpiece is assembled in a predetermined assembly state using a jig and positioned. Then, it is temporarily attached by spot welding with a welding robot or the like, and then incremental welding is performed.

For example, even when manufacturing an automobile body, a plurality of workpieces are positioned in a predetermined assembly state and welded to form subassemblies such as an underbody, left and right side members, and a roof, and these subassemblies are further enlarged. The positioning jig is used for positioning and bonding.
JP 2003-146262 A Japanese Patent Laid-Open No. 9-123961

  In recent years, the production bases of automobiles have expanded to overseas, and the number of small-scale productions at each production base has increased. In this case, mass production is improved by manufacturing each workpiece at one production site and assembling it at each overseas production site. However, a plurality of workpieces are positioned in a predetermined assembly state. In addition, it was necessary to introduce a large positioning jig to each production base. For this reason, the equipment cost was increased.

  The workpiece joining method according to the present invention includes an assembly step for assembling workpieces in a predetermined assembly state, and a temporary fixing step for temporarily fixing workpieces assembled in a predetermined assembly state in the assembly step by spot welding. , While making an assembly hole in the spot welded part formed in the temporary fixing process, canceling the joint by spot welding and separating the workpiece, and positioning the workpiece in a predetermined assembly state using the assembly hole And a main joining step of main joining the workpieces. This workpiece joining method can also be applied to the case where workpieces are joined together to create a subassembly, and further the subassemblies are joined together.

  According to this work joining method, for example, when producing a small amount at a production base such as overseas, the above assembly process, temporary fixing process and work separation process are performed at one production base, and the work is assembled into a predetermined assembly. An assembly hole to be assembled to the state is formed. In this state, each work is transported to each production base, and at each production base, the work is positioned in a predetermined assembly state using the assembly holes, and the work is finally joined. Thereby, in each production base, the assembly jig used for workpiece positioning can be made unnecessary or simple, and the equipment cost can be kept low.

  Hereinafter, a work joining method according to an embodiment of the present invention will be described with reference to the drawings, taking as an example the case of joining side members of an automobile.

  As shown in FIG. 1, for example, the side member 1 of this embodiment includes a body side outer A, a side roof rail inner B, a center pillar inner lower C, a center pillar upper hinge support D, a front pillar, It is assembled by assembling inner parts such as inner upper E, front pillar inner lower F, and front pillar inner lower reinforcement G and welding them together. Each of the subassemblies A to G may be configured by joining a plurality of workpieces constituting the subassembly in a predetermined assembly state.

  In this workpiece joining method, first, an assembly hole is formed so that workpieces can be assembled without using an assembly jig.

  In this embodiment, although illustration is omitted, the workpieces constituting each of the sub-assemblies A to G are assembled in a predetermined assembly state using an assembly jig (assembly process). Next, the workpieces assembled in this assembling step are temporarily fixed by spot welding (temporary fixing step). Next, using a large assembling jig, the subassemblies A to G are assembled so as to constitute the side member 1 as shown in FIG. 1 (assembly process), and the assembled subassembly A is assembled. ~ G is temporarily fixed by spot welding (temporary fixing step).

  Next, as shown in FIG. 2, the spot welded portion s formed in the temporary fixing process is released from the joint by spot welding while opening the assembly hole t, and the subassemblies A to G are separated (work separating process) ). Further, the workpieces constituting the sub-assembly are also separated by making an assembly hole in the spot welded portion if necessary for the request of packaging during transportation (work separation step).

  In the workpiece separation process, spot welding welding marks are removed in the temporary fixing process by releasing spot welding while drilling the assembly holes with a drill having a larger drill diameter than the spot weld spot welded in the temporary fixing process. It may be eliminated.

  Further, as the spot welding electrode used in the temporary fixing process, for example, as shown in FIG. 3, a spot electrode having projections 13 and 14 at the spot welded portion s at the center of the electrodes 11 and 12 is used. A recess for guiding a drill may be formed in the part when forming the assembly hole in the workpiece separation step.

  In the workpiece separation process that forms assembly holes in this way, assembly is necessary for separating the workpiece and accurately positioning the workpiece by opening the assembly hole in the spot welded part where the workpiece is temporarily attached and separating the workpiece. Since the hole forming operation can be performed simultaneously, both the work efficiency and the positioning accuracy can be improved.

  Next, the main joining of workpieces will be described.

  In the main joining of the workpieces, the workpieces are positioned in a predetermined assembly state using the assembly holes h opened in the workpiece separation step, and the workpieces are finally joined (main joining step). When assembling the workpiece, for example, the workpiece may be assembled using fastening means such as rivets and bolts and nuts. In this case, as shown in FIGS. 1 and 2, the assembly hole h formed between the workpieces is a hole formed in the spot welding portion s in which the workpiece is temporarily fixed in the temporary fixing step, in the workpiece separation step. Therefore, each workpiece can be accurately positioned by accurately fitting and fastening the assembly holes h. Thereby, in this joining process, it can position without using an assembly jig or using a simple assembly jig.

  According to this work joining method, if the assembly process, the temporary fixing process and the work separation process are performed in one production base among the above processes, the work in which the assembly holes are formed is transported to each production base. Each production site can perform the main joining process without using an assembly jig or using a simple assembly jig. Thereby, in the production base which performs this joining process, the assembly jig which positions a work can be made unnecessary or simple, and the equipment cost in each production base can be held down by this.

  The work joining method according to one embodiment of the present invention has been described above with reference to the drawings. However, the work joining method according to the present invention is not limited to the above-described embodiment.

  For example, although the joining of each work (subassembly) constituting the side member of an automobile is illustrated, the present invention is not limited to this, and the present invention can be applied to various uses for positioning and joining the work (subassembly). Moreover, although the method which carries out the main joining of the workpiece | work at the main joining process illustrated welding, it can be applied also when performing this joining by methods other than welding.

The figure which shows the welding structure of the side member of a motor vehicle. The figure which shows a workpiece | work isolation | separation process. The figure which shows embodiment of the electrode used for spot welding.

Explanation of symbols

1 Automobile side members A to G Subassembly h Assembly hole s Spot weld

Claims (2)

In a workpiece joining method for joining a plurality of workpieces to a predetermined assembly state,
An assembly process for assembling the workpieces in a predetermined assembly state;
A temporary fixing step of temporarily fixing the workpieces assembled in a predetermined assembly state in the assembly step by spot welding;
A workpiece separation step of separating the workpiece by releasing the joint by spot welding while opening an assembly hole in the spot welding portion formed in the temporary fixing step,
A workpiece joining method comprising: a main joining step of positioning the workpieces in a predetermined assembly state using the assembly holes, and finally joining the workpieces.   In the temporary fixing step, a spot electrode having a protrusion smaller than the assembly hole formed in the temporary fixing step in the spot welded portion is used at the center of the electrode, and a drill is formed when forming the assembly hole in the workpiece separation step. The work joining method according to claim 1, wherein a recess for guiding is formed.