JPS6261394B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a workpiece guiding device for a seam welding machine that is capable of automating seam welding of workpieces that form complex welded parts, such as fuel tanks for two-wheeled vehicles.

Conventionally, seam welding of workpieces with a one-dimensional or two-dimensional welding part shape has been automated using a copying cam. In cases where the welded part has a three-dimensional shape, such as the fuel tank A for two-wheeled vehicles, in which the flange parts c of the two parts are joined and seam welded to form an integral part, robots are used to automate the process. However, unless each arm of the robot is formed into an arm to be controlled by a control device, it will be difficult to control the posture of the workpiece to change according to the curved surface of the workpiece. This has the disadvantage that the number of control devices increases and the size increases, making it inapplicable to small fuel tanks and the like.

The purpose of the present invention is to improve such disadvantages by minimizing the number of arms to be controlled by the robot, and by supporting the robot arm and the chucking device by a free arm having degrees of freedom in two axial directions. An object of the present invention is to provide a device which allows a workpiece to be welded to be smoothly guided.

To explain this with reference to the illustrated embodiment, reference numeral 1 indicates a seam welding machine main body, and the main body 1 includes an upper electrode roller 2, a lower electrode roller 3, a knurl 4, and a pressure cylinder 5. A robot 7 is provided which has a chucking device 6 that holds the workpiece A to be welded in order to guide the workpiece A sandwiched therebetween, and the robot 7 rotates on the welding point of the electrode rollers 2 and 3. The first rotating arm 8
A first swing arm 9 is pivotally supported by the arm 8 to swing, a second swing arm 10 is also pivotally supported by the arm 9, and a second swing arm 10 is pivoted by the arm 8 to swing. It consists of a second pivot arm 11 that is pivotally supported, and each of these arms has a pivot control member 8a, 9a,
10a and 11a are formed on the controlled object arm. The robot 7 and the chucking device 6 include a rod-shaped free swinging arm 12 which is pivotally supported by the second swing arm 11 of the robot 7 via a pin 11b, and a rotatable arm 12 at both ends of the arm 12. The chucking device 6 is attached to the tip of the robot 7 via a free arm consisting of a U-shaped free swinging arm 13 that is pivotally supported. The angle can be changed freely within the frame. The chucking device 6 is formed with a Y-shaped yoke, and a freely rotating arm 13 is attached to the branching point of the yoke, and a refueling port formed on the workpiece is held at the attachment point at the tip of the central support rod. At the same time, the outer wall of the workpiece was adsorbed to the adsorption pieces at the tips of the left and right branch rods.

Next, to explain its operation, each arm 8, 9, 10, 11 of the robot 7 consists of arms to be controlled.
The electrode rollers 2 and 3 operate according to a pre-teaching trajectory, and the welding part of the workpiece is sequentially moved by the upper and lower electrode rollers 2 and 3.
Welding is performed by moving the welding part of the workpiece three-dimensionally, but when the welding position shifts toward the lower electrode roller 3 due to electrode wear, etc., each part of the robot 7 If the arms 8, 9, 10, and 11 only move according to their trajectories, they will not be able to follow this motion, and an unreasonable force will be applied to the chucking device 6, making it impossible to accurately hold the workpiece. In addition, two arms are required to be controlled, but in the present invention, the part to be welded is held between the electrode rollers 2 and 3 at the welding position, so there is no unreasonable force exerted on the chucking device due to the deviation of the welding position. The force can be freely rotated even by the free arms 12 and 13 which do not have a biaxial control device, and it is possible to prevent excessive force from being applied to the chucking device 6.

In this way, according to the present invention, the chucking device provided at the tip of the arm of the robot is attached via a free arm that can freely change its angle within at least two planes perpendicular to the horizontal plane between the seam electrodes. Therefore, deviations in the welding position due to electrode wear, etc. can be adjusted by the free arm without increasing the number of arms to be controlled by the robot 7, making it possible to miniaturize the robot and facilitate three-dimensional guidance of small objects to be welded. It has an effect that can be done to.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a front view, FIG. 2 is a front view of the main parts, and FIG. 3 is a front view of the main parts.
FIG. 4 is a front view of the object to be welded. 2... Upper electrode roller, 3... Lower moving electrode roller, 6
...chucking device, 7...robot, 11...robot arm, 12, 13...free arm.

Claims (1)

[Claims] 1. In a workpiece guiding device for a seam welder, in which a workpiece is attached to a chucking device provided at the tip of a robot arm, and the welded part of the workpiece is inserted between seam electrodes to sequentially feed the workpiece. , the chucking device is placed at the tip of the arm,
At least 2 orthogonal to the horizontal plane between the seam electrodes
A workpiece guiding device for a seam welding machine, characterized in that it is attached via a free arm that freely changes angle within a plane.