JP2692435B2 - Simple multi-spot welding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spot welding apparatus for welding a panel material as a work, and more particularly to a multi-spot welding apparatus for welding a tunnel portion formed in the work.

[0002]

2. Description of the Related Art The body of an automobile is composed of a large number of panel materials, and most of them are generally spot welded to assemble them. Spot welding is a method that melts and joins the contacted parts of the pressed work by pressing the work with electrodes and applying a large current between both electrodes for a short time. Is excellent.

Further, in order to assemble a vehicle body, the vehicle body is sequentially transported to each welding stage arranged at a predetermined interval on an assembly line, and a transfer bar used for this transportation is conventionally one transfer stage. There are a bar type and a two transfer bar type. Comparing one transfer bar with two transfer bars, one transfer bar has the advantage that less capital investment is required and the work space is relatively large. The transfer bar is a bar to which fingers for supporting the work at the time of transfer are attached at equal intervals. In the lift-and-carrier type transfer bar, the fingers make contact with the work during the transfer bar ascending operation, lift the work while supporting it from below, transfer the work to the work jig table of the next welding stage, and place it by the descending operation. After the placement, the operation of returning to the original position is performed. In the transfer bar that only reciprocates, the work is transferred from the transfer bar to the jig base by moving the work jig base vertically.

In the past, spot welding was carried out using an industrial robot, but since the robot welds one point at a time, the number of hit points per unit time is far smaller than in a multi-welding apparatus. Also, if the number of RBIs is small, the robot's ability to remember many steps is not fully utilized,
It will result in inefficient capital investment.

At present, the introduction of multi-spot welding is in progress in order to further improve the work efficiency. Since multi-spot welding is a method of spot welding at a plurality of locations in one operation, it is necessary to apply pressure while sandwiching the vehicle body from both sides with electrodes across the entire joint. Therefore, a large space is required compared to the work performed by humans or robots. For this reason, when the multi-spot welding apparatus is introduced into the assembly line, the installation space of the multi-spot welding apparatus is restricted by the auxiliary equipment such as the transportation equipment of the vehicle body forming the assembly line.

[0006]

Regarding the spot welding work of the vertical wall of the tunnel portion of the floor main panel in the floor main process, since the vertical wall of the tunnel portion is located at the central portion of the panel, two transfer bars are used. Although it is possible to arrange a multi-spot welding machine in an assembly line that has, the transfer bar is located right under the center of the floor panel in one, so that the multi-spot welding machine must be installed in the line so far. Was impossible. Therefore, conventionally, spot welding was performed using a robot having a dedicated gun (barracuda) for tapping the vertical wall of the tunnel.

In view of the above-mentioned problems of the prior art, the present invention is incorporated in a floor main process line having a transfer bar that supports and conveys the central portion of a work (floor panel), and is formed in the central portion of the work. An object of the present invention is to provide a multi-spot welding device capable of welding to a formed tunnel portion.

[0008]

In order to achieve the above object, the present invention provides a welding device for welding the tunnel portion of a work having a tunnel portion extending in the longitudinal direction at the center, and supporting the center portion of the work. Transfer bar, a work jig table for holding the work transferred by the descending movement of the transfer bar, and a transfer of the work when the work is held on the work jig table. A welding stage provided with a reciprocatingly installed rotating block that advances to the welding position in a direction perpendicular to the direction and horizontally, and enters into the tunnel portion by the rotating operation of the rotating block at the welding position. An electrode unit attached to the rotating block, and reciprocally movable between a welding position and a retracted position,
A simple multi-spot welding apparatus, comprising: a stud gun provided with an electrode for pressing the electrode provided in the electrode unit through the work.

[0009]

In the invention thus specified, the work is delivered from the transfer bar to the work jig base by the downward movement of the transfer bar that supports and conveys the central portion of the work. After the work and the transfer bar are separated from each other, the rotary block advances to a welding position in a direction perpendicular to the work transfer direction and horizontally. Then, as the rotary block rotates, the electrode unit provided in the rotary block enters the tunnel portion of the work, and the electrode of the stud gun is pressed through the work by the electrode provided in the electrode unit. . In this state, spot welding is simultaneously performed at a plurality of points in the tunnel portion. In other words, multi-spot welding can be performed on the tunnel portion of the work without receiving the interference of the transfer bar that exists immediately below the center.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 shows one welding stage that constitutes a line for assembling a floor main of an automobile body. In this line, one transfer bar 1 conveys a panel P which is a work. This transfer bar 1
Is a lift-and-carrier type, and the panel P supported by the fingers 2 attached to the transfer bar 1 at the stage of the previous process is moved by the forward movement and the downward movement of the transfer bar 1 as shown in FIG. It is delivered to the work jig base 3 provided on this welding stage. FIG. 1 shows a state where the transfer bar 1 is at the lower limit position, and from this state, the transfer bar 1 moves backward by a stroke up to the front stage.

At a position where it does not interfere with the transfer bar 1, a guide 4 is laid in a direction substantially perpendicular to the direction in which the panel is conveyed, and a slide base 5 is reciprocally movable along the guide 4. ing. In FIG. 1, a rotary shaft 6 that extends horizontally in a direction perpendicular to the transport direction of the panel P is rotatably mounted on a pedestal 7 on the slide base 5, and the rotary shaft 6 is rotated. A rotary actuator 9 connected to a rotary shaft 6 via a coupling 8 for driving is mounted on the slide base 5.

At the tip of the rotary shaft 6, the rotary block 1
0 is fixed, and a receiving shaft 11 that is concentric with the rotating shaft 6 is fixed to the front end surface of the rotating block 10. The guide bracket 12 installed on the opposite side of the sliding base 5 via the transfer bar 1 includes a receiving base 7
The bearing 13 is attached so as to face the bearing 13. The bearing 13 has a fitting hole into which the receiving shaft 11 is fitted.

An electrode unit 15 is attached to the rotary block 10 via an insulator 14. When the rotary block 10 is rotated at the welding position shown in FIG. 1, the electrode unit 15 enters the tunnel portion T. Therefore, as shown by the phantom line in FIG. 3, from this state, when it is rotated 90 degrees, the vehicle exits from inside the tunnel portion T. The electrode unit 15 is provided with a plurality of insert electrodes 16 corresponding to the welding positions of the vertical wall of the tunnel portion T of the panel P. Therefore, as shown in FIG. 2, when the sliding table 5 is moved forward from the state where the sliding table 5 is in the retracted position with the electrode unit 15 retracted, the receiving shaft 11 is fitted into the bearing 13. To meet.
Then, when the rotating block 10 is rotated by 90 degrees, FIG.
As shown in, the electrode unit 15 enters the tunnel portion T. A lock pin (not shown) is fitted into the lock hole 17 formed in the rotary shaft 10 in order to lock the electrode unit 15 when it is in such a state. However, a lock pin may be fixed to the lock hole 17 and a block having a lock hole for fitting with the lock pin may be slidably mounted on the slide base 5.

The welding stage shown in the figure has a tunnel portion T.
Corresponding to the left and right vertical walls, swing mechanism parts 21 and 22 are provided that are swingable between a welding position shown in FIG. 1 and a retracted position on both sides of the panel.
A stud gun 24 having an electrode 23 corresponding to the insert electrode 16 provided in the electrode unit 15 and pressed through the panel P is attached to each of the swing mechanism parts 21 and 22. There is.

Next, an operation procedure of multi-spot welding using this apparatus will be described.

FIG. 2 shows a finger 2 of the transfer bar 1.
After being transferred to the welding stage shown in the figure by the forward movement of the transfer bar 1 while being supported by the transfer bar 1, the transfer bar 1 is moved downward and the panel P is mounted on the work jig table 3 provided on this stage. It shows the placed state. At this time, in order to avoid buffering between the transfer bar 1 and the electrode unit 15, as shown in FIG.
The electrode unit 15 is retracted to the retracted position by the slide table 5, and the transfer bar 1 is further moved to the lowest position shown in FIG. 1 and then retracted.

Under this condition, the slide base 5 moves to the left in FIG. 2 (the direction perpendicular to the transport direction of the panel P and horizontally) from the position where it does not interfere with the transfer bar 1, and the receiving shaft. The portion 11 is inserted into the fitting hole of the bearing 13, and the rotation block 10 moves to the welding position. Next, when the rotary actuator 9 is activated, the rotary shaft 6 and the rotary block 10 rotate, whereby the electrode unit 15 moves from the state shown by the virtual line to the state shown by the solid line in FIG. Enter in T. On the other hand, the stud gun 24 moves from the retracted position to the welding position shown in FIG.
The electrode 23 of 4 inserts the insert electrode 16 while sandwiching the panel P.
And is welded to the tunnel portion P of the panel P at a plurality of locations at the same time. After the welding work is completed,
After the electrode unit 15 is retracted from the tunnel portion T and the rotary block 10 is rotated, the slide base 5 returns to the retracted position in FIG. In this state, transfer bar 1
Thus, the panel P is transported to the next step. In the illustrated embodiment, the transfer bar 1 is a lift-and-carry type, but the present invention can also be applied to the case where the transfer bar has a transfer device of only reciprocating type.

[0018]

As described above, according to the present invention, without receiving the interference of the transfer bar located directly under the center,
Multi-spot welding can be performed on the tunnel part of the work. That is, the present invention provides a multi-spot welding apparatus that is incorporated into a floor main process line having a transfer bar that supports and conveys the center of a work (floor panel) and can weld to a tunnel formed in the center of the work. Can do things

[Brief description of the drawings]

FIG. 1 is a sectional view showing a simple multi-spot welding apparatus according to an embodiment of the present invention showing a state in which multi-spot welding is performed on a tunnel portion of a panel.

2 is a cross-sectional view of the welding apparatus shown in FIG. 1 in a state where the electrode block is in a retracted position,

FIG. 3 is a sectional view through the center of the electrode in FIG.

[Explanation of symbols]

1 ... Transfer bar 2 ... Finger 3 ...
Work jig base 4 ... Guide 5 ... Sliding base 6 ...
Rotating shaft 9 ... Rotary actuator 10 ...
Rotating block 14 ... Insulator 12 ... Guide 15
... Electrode unit 16 ... Insert electrodes 21, 22
... Swing mechanism 23 ... Electrode 24 ... Stud gun P ... Panel T ... Tunnel

Claims (1)

(57) [Claims] 1. A welding apparatus for welding the tunnel portion of the workpiece having a tunnel portion in the longitudinal direction in the center, transfer bars for supporting and transferring the central portion of the workpiece, receiving by the lowering movement of the transfer bars a workpiece fixture table to hold the front <br/> Symbol workpiece passed Ru, to the workpiece fixture base, in a state in which the workpiece is held, the work
And a rotating block that is reciprocally installed to move forward to the welding position in a direction perpendicular to the transport direction of
By the provided welding stage , the rotating operation of the rotating block at the welding position ,
Attached to the rotating block that goes into the tunnel
Vignetting the electrode unit, and a reciprocably the welding position and the retracted position, the electrode provided in the electrode unit, through the workpiece, stud gun electrodes are provided to pressurize, to have a Characteristic simple multi-spot welding equipment.