JPH054948Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a spot welding device that performs spot welding using a robot, and particularly to a spot welding device suitable for multi-product mixed production.

[Conventional technology]

When spot welding workpieces placed on a conveyor line, especially when performing spot welding on uneven surfaces such as automobile floor panels using upper and lower electrodes, it has traditionally been difficult to accurately determine the welding position and angle. A dedicated upper fixed electrode and lower fixed electrode were used to hold the workpiece in place.

For this reason, when spot welding many types of workpieces, it is necessary to prepare dedicated electrodes and jigs for each type of workpiece, and moreover, many man-hours are required when changing the line, resulting in production There was a problem with the outage period.

As a means for solving this problem, a proposal disclosed in Japanese Patent Application Laid-Open No. 184477/1983 is known. As shown in Fig. 3, this proposal consists of a plurality of moving platforms 2 movably placed on a rail 1.
A clamp device 4 is provided to hold the workpiece 3, a plurality of spot welding guns 6 are movably mounted on the upper part of the machine frame 5, and the movable table 2 is moved upward by the cylinder 7 at the welding position. Spot welding is performed by aligning and abutting the workpiece 3 to the position of the spot welding gun 6. Air is supplied to the movable table 2 by operating an air cylinder 8 fixed to the machine frame 5, and the clamping device 4 is operated to clamp the workpiece 3.

According to this proposal, line switching for at least two types of workpieces is possible by switching the spot welding gun 6 to the machine frame 5.
This can be done by simply moving the clamp device 4 from above, and the clamp device 4 can be operated using simple air piping.

Furthermore, as a conventional spot welding apparatus of this type, one is known that has a structure in which a pair of stud robots 9 are fixedly disposed on both sides of a welding line, as shown in FIG.

[Problem that the invention attempts to solve]

However, according to the conventional spot welding apparatus shown in FIG. Because of the regulations, there was a problem in that a pit 10 had to be provided under the floor and it had to be stored in this pit 10.

Another problem is that the spot welding guns 6 must be prepared according to the type of workpiece, and there is a limit to the number of spot welding guns that can be mounted on the machine frame 5.

Further, in the conventional spot welding apparatus shown in FIG. 4, since the robots are arranged in the width direction of the conveyance line, there is a problem that the robot occupies a large amount of space.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a simple and compact spot welding device that can easily switch lines for a wide variety of workpieces.

[Means for solving problems]

In order to achieve the above object, the present invention clamps and pressurizes a workpiece placed on a conveyance table between an upper gun and a lower electrode, and conducts welding by passing current between the upper electrode and the lower electrode. In spot welding equipment,
An upper robot and a lower robot are mounted on a base, and the upper robot positions the upper electrode at an arbitrary position and angle.Meanwhile, the arm of the lower robot is inserted under the workpiece, and the tip of the arm is The position and angle of the lower electrode attached to the upper electrode can be adjusted by a lower robot so that it is perpendicular to the workpiece and faces the upper electrode.

[Effect]

According to the above configuration, by setting the movements of the upper robot and the lower robot to match the shape and position of the workpiece, the upper electrode and the lower electrode can be easily positioned at the correct position through the workpiece, There is no need to prepare a dedicated upper electrode, lower electrode, and a jig for mounting these for each workpiece. Furthermore, since the robot can be arranged in the height direction, the space occupied by the welding equipment can also be reduced.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a spot welding apparatus according to the present invention will be described below with reference to the drawings.

An embodiment of the present invention is shown in FIGS. 1 and 2.

The base 12 provided on the conveyance line 11 has four
Book pillars 13 are erected, and among these four pillars 13, two pillars 13a, 13b and 1 which are adjacent in the direction perpendicular to the conveyance line 11
At the upper ends of 3c and 13d, there are rails 14a,
14b is attached.

Two machine frames 15a, 15 are mounted on these rails 14a, 14b in parallel to the transport line 11.
b is guided and movably mounted on rails 14a and 14b.

Support shafts 16a and 16b are vertically fixed to these machine frames 15a and 15b, respectively, and arms 17a and 17b are respectively attached to these support shafts 16a and 16b so as to be movable up and down.

Furthermore, bending shafts 19a and 19b are provided at the tips of these arms 17a and 17b via horizontal pivot shafts 18a and 18b, respectively, and an upper gun 20 and a lower electrode 21 are provided at the tips of these bending shafts 19a and 19b, respectively. is installed. The upper gun 20 and the lower electrode 21 are set at predetermined positions and angles by a five-axis robot made up of the above-mentioned members. At this time, the arm 17b extends below the workpiece 22 so that the upper gun 20 to which the upper electrode 22 is attached and the lower electrode 21 sandwich the workpiece 23 from above and below as shown in FIG. 22 and the lower electrode 21 are positioned so as to press the workpiece 23 in a perpendicular direction.

Next, the operation of this embodiment will be explained.

Work 23 being transported on the transport line 11
In this spot welding apparatus, the movements of the upper robot and the lower robot are set so that the upper electrode 22 and the lower electrode 21 clamp and press the workpiece 23 in a direction perpendicular to the surface. Then, the lower electrode 21 is positioned below the workpiece 23 by the lower robot, and brought into contact with the workpiece 23.

At the same time, the upper robot performs a positioning operation of the upper gun 20, and the upper electrode 22 and the lower electrode 2
The welding part of the workpiece 23 is clamped and pressurized in the same axial direction by 1 and 1, and then energization and opening are performed.
Weld the dots. By repeating this operation, the works 23 that are successively conveyed are spot welded.

According to this embodiment, spot welding can be performed at arbitrary welding point positions on different types of workpieces 23 using two robots, the upper and lower robots, and the apparatus can be made more versatile.

As a result, it is no longer necessary to prepare dedicated fixed electrodes and jigs for each type of workpiece 23 as in the conventional example, making it easier to switch production lines, reducing switching costs and significantly reducing the period of production stoppage for switching. It became possible to shorten the time.

Furthermore, by arranging the main mechanical parts above the mounting, a large space is not required as in the conventional robot arrangement shown in FIG. 4, and the space can be halved.

[Effect of idea]

As described above, according to the present invention, since the two robots (upper and lower) are used to position the upper and lower electrodes in conjunction with each other, line switching is facilitated when mixed production of various types of workpieces is performed. Since dedicated electrodes and jigs are not required, it is possible to reduce switching costs and shorten the period of production stoppage for switching, and furthermore, it is possible to significantly reduce the space occupied by the device.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of a spot welding device according to the present invention, FIG. 2 is a side view of the main part of FIG. 1, and FIGS. 3 and 4 are side views showing conventional spot welding devices, respectively. FIG. 2 is a diagram and a perspective view. 11... Conveyance line, 12... Base, 17b...
...Arm, 21...Lower electrode, 22...Upper electrode, 23...Work.

Claims (1)

[Claims for Utility Model Registration] (1) A workpiece placed on a conveyor table is held and pressurized between an upper electrode and a lower electrode, and current is applied between the upper electrode and the lower electrode to perform welding. In a spot welding device, an upper robot and a lower robot are mounted on a base, and the upper robot positions the upper electrode at an arbitrary position and angle, while the arm of the lower robot is inserted under the workpiece. A spot welding device, characterized in that the position and angle of the lower electrode attached to the tip of the arm can be adjusted by a lower robot so that it is perpendicular to the workpiece and faces the upper electrode. (2) The upper electrode and the lower electrode are each mounted on a pedestal by an upper robot and a lower robot so that they can move in three axes orthogonal to the workpiece, rotate horizontally, and rotate the tip. A spot welding device according to claim 1 of the utility model registration claim.