JPH0780688A - Method for clamping vehicle body panel - Google Patents

Abstract

PURPOSE:To assure the welding accuracy of a vehicle body panel and other parts. CONSTITUTION:Air cylinders 4, 6, 7 are respectively actuated by signals from a controller 11 to first clamp a part A, part C and part D at the time of welding the dash lower panel 1 and a hood ridge panel 2 and under body 3 of the front engine front drive vehicle. The end of clamping of these parts is confirmed by a clamping end sensor 12 and thereafter, an air cylinder 5 for clamping is actuated to clamp the part B. As a result, the welding is executed in a stable clamping state without assisting the deformation by a spring back.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for clamping a vehicle body panel when welding the vehicle body panel to another member.

[0002]

2. Description of the Related Art Conventionally, when welding a vehicle body panel to another member, a plurality of portions of the vehicle body panel are clamped (see, for example, Japanese Patent Application Laid-Open No. 62-11058). It is being appreciated. For example, when assembling the dash lower panel 1 in the front engine front drive vehicle shown in FIG. 1 by welding with the hood ridge panel 2 and the underbody 3 shown by dotted lines, the points A, B, C shown by the hatched portions of the dash lower panel 1 are assembled. ，
Clamp section D (two on each side, left and right).

[0003]

However, the conventional method of simultaneously clamping a plurality of points has the following problems. In the case of the dash lower panel 1,
As shown by the dotted line in FIG. 2, the front surface welded to the hood ridge panel 2 may be deformed inward (+ Y direction) by the springback phenomenon with respect to the regular shape shown by the solid line.

In this state, the dash lower panel 1 from A to
When the D section is clamped at the same time, the clamp in the B section may operate slightly ahead of the C section due to variations in the air flow rate of the clamping air cylinder. In that case, the front surface of the dash lower panel 1 As shown in Fig. 3, it is in the same direction as the springback deformation (+ Y direction).
In some cases, the amount of deformation becomes too large at the C portion, and the clamp cannot be completely clamped. As a result, the accuracy of welding is affected and the accuracy after assembly is varied.

The present invention has been made in view of the above-mentioned problems of the prior art, and the accuracy after welding can be secured by clamping in accordance with a preset order so that the deformation immediately before clamping can be sufficiently reduced. An object of the present invention is to provide a method for clamping a vehicle body panel.

[0006]

Therefore, a method of clamping a vehicle body panel according to the present invention is a method of clamping a plurality of portions of the vehicle body panel when the vehicle body panel is welded to another member. It is characterized in that a plurality of points are clamped with a time difference according to a set order.

[0007] For example, the vehicle body panel is a dash lower panel in a front engine front drive vehicle, and the rear portion of the dash lower panel is projected rearward to clamp the flange portion connected to the side sill of the vehicle body lastly. be able to.

[0008]

[Function] The clamp portion, which is largely deformed by spring go or spring back and is further deformed by the clamp of the other portion, is clamped first and then the other clamp portion is clamped beforehand. If the clamping order is set and clamping is performed according to the order, the portion having a relatively large deformation amount is firmly clamped first, and the other clamping portions are stably clamped without being affected by it. .

Therefore, since the vehicle body panel is clamped in a shape close to a regular shape, the welding accuracy is improved and the accuracy of the product after welding is improved. As described above, since both sides of the front surface of the panel are deformed by the springback so as to be curved backward, after clamping the deformed portion first,
Finally, a stable clamp can be performed by clamping the flange portion connected to the side sill of the vehicle body.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1 showing an embodiment, as described above, the dash lower panel 1 has a portion A at the lower end edge, a portion B at a flange portion that extends rearward from both lower sides and is connected to side sills of the vehicle body, and a portion C at both upper edge portions. After clamping the D part, in which the positioning hole is formed in the upper part of the front surface, by the clamping air cylinders 4, 5, 6, 7 at two places on each side, spot welding is performed on the hood ridge panel 2 and the underbody 3 to form an assembly. .

In the present invention, the parts A, C and D are clamped at the same time, and the part B is clamped after the clamping of these parts is completed. So C
A clamp end sensor 12 for detecting the end of the clamp by detecting the piston position or the like is provided in the clamp air cylinder 6 of the part, and the detection signal is input to the control device 11. The control device 11 includes a microcomputer, and includes an R
According to the program stored in the OM, the welding is performed after performing the clamping in a predetermined order based on the detection signal from the clamp end sensor 12.

The control operation of the control unit 11 will be described with reference to the flow chart shown in FIG. In step (denoted as S in the figure. The same applies hereinafter) In step 1, the loading of the dash lower panel 1 to the welding position is confirmed. In step 2, the clamp air cylinders 4, 6 and 7 are operated to set A
Part C and D are clamped at the same time.

In step 3, the clamp end sensor is
12 signals are input and it is determined whether or not the clamp is completed. And when it is detected that the clamp is finished,
Proceeding to step 4, the clamping air cylinder 5 is operated to clamp the portion B. In this way part A ~
With the D part clamped, the process proceeds to step 5, where spot welding is performed on each part, and the dash lower panel 1, the hood ridge panel 2, and the underbody 3 are assembled.

According to such a clamping method, the clamp of the portion (B portion) which increases the deformation due to the spring back when it is clamped first is replaced with the other clamp portion (A portion,
C part, D part) after clamping, and
This rearward projecting portion (B portion) has a small area, and since it is easy to correct only this portion, it is possible to firmly clamp all the clamping portions and ensure welding accuracy.
In addition, product accuracy can be secured.

[0015]

As described above, according to the present invention, there is provided a body panel clamping method for clamping a vehicle body panel, such as a dash lower panel of a front engine front drive vehicle, at a plurality of positions to weld other parts to the vehicle body panel.
Since the method is to clamp with a time lag in a predetermined order, the part that is deformed by springback or spring go is clamped first, and the clamp of the part that promotes the deformation when clamped first is delayed. By setting the clamping order to, it is possible to firmly clamp all the parts and improve the accuracy of welding with other parts of the vehicle body panel, which in turn can improve the processing accuracy of the vehicle body structure.

[Brief description of drawings]

FIG. 1 is an overall system configuration diagram showing an embodiment of the present invention.

FIG. 2 is a view on arrow A of FIG. 1 showing a change in the shape of a dash lower panel.

FIG. 3 is a view from the arrow B of FIG. 1, which also shows changes in the shape of the dash lower panel.

FIG. 4 is a flowchart showing a method according to the present invention.

[Explanation of symbols]

 1 Dash lower panel 2 Hood ridge panel 3 Underbody 4, 5, 6, 7 Air cylinder for clamp 11 Controller 12 Clamp end sensor

Claims (2)

[Claims] 1. When welding a body panel to another member,
A method for clamping a plurality of parts of the vehicle body panel, wherein the plurality of parts to be clamped are clamped with a time difference according to a set order. 2. The vehicle body panel is a dash lower panel in a front engine front drive vehicle, wherein the flange portion projecting rearward from the lower portions on both sides of the dash lower panel and connected to the side sill of the vehicle body is finally clamped. The method for clamping a vehicle body panel according to claim 1.