JPS61289982A - Work guiding device in seam welding machine - Google Patents

Abstract

PURPOSE:To execute automatic and efficient seam welding even in the case in which the weld zone of a work has a three-dimensionally curved shape by constructing a wrist part in such a manner that said part can be freely moved three-dimensionally in optional directions by a robot thereby controlling the movement thereof. CONSTITUTION:The proper point of a flange part (c) of a fuel tank A is placed on a lower electrode roll 3 while the tank is held gripped to a chucking device 8. An upper electrode roll 2 is then lowered to hold the flange part (c) in place between the rolls 2 and 3. The roll 2 is rotated and at the same time a robot body 11 and both arms 12, 13 are operated to move the wrist part 9 along the preliminarily taught three-dimensional loci. The attitude of the tank A is three-dimensionally changed by the movement of the three axes 17a, 18b, 18c of the wrist part 9 by which the flange part (c) is continuously fed between both rolls 2 and 3.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a work guiding device in a seam welding machine for automating seam welding of works such as fuel tanks for two-wheeled vehicles.

(Prior art) Conventionally, when workpieces are welded by old G or TIG welding, the workpiece is generally fixed and the welding torch is moved by a robot, but seam welding is performed with the workpiece fixed. In this case, a heavy welding unit that incorporates a pair of electrode rolls, their pressure mechanism, and a rotational drive mechanism must be mounted on the robot, which slows down the robot's operating speed and reduces productivity. becomes worse.

(Problem to be Solved by the Invention) In this case, a stationary seam welding machine is used, the workpiece is moved by a robot, and the welded part of the workpiece is fed between a pair of electrode rolls provided in the welding machine. However, as shown in the motorcycle tank A shown in Fig. 2, it is possible to
When seam welding a welded part having a dimensionally curved shape, three-dimensional movement control and posture control of the workpiece are required.

Furthermore, if the robot is placed on the floor, the installation space for the entire device including the seam welding machine will increase, and furthermore, the robot will be more likely to be exposed to cooling water that is applied to the workpiece, and there is a concern that there will be adverse effects such as rust.

(Means for Solving the Problems) An object of the present invention is to provide a device that solves the problems, and includes a wrist portion with a three-axis structure that supports a characterizing device that grips a workpiece. The seam welding machine is characterized in that a robot capable of moving in any three-dimensional direction is mounted on the body of the seam welding machine.

(Example) The present invention will be explained with reference to the illustrated embodiments.

Referring to FIG. 1 and FIG. 2, (1) shows the body of a seam welding machine, and a pair of upper and lower electrode rolls (2) (3) are provided at the front part of the body (1). Upper electrode roll (2)
is an electrode holder (
The holder (5) is provided with a knurl (6) that comes into contact with the circumferential surface of the upper electrode roll (2), and a drive source (not shown) is used to drive the upper electrode roll (2) through the knurl (6). The upper electrode roll (2) is driven to rotate, and lowering of the upper electrode roll (2) by the pressure cylinder (4) lowers the lower part pivotally supported on the electrode holder (7) fixed to the body (1). The above-mentioned flange portion C of the fuel tank A for a two-wheeled vehicle, which is a workpiece, is sandwiched between the electrode roll (3) and the upper electrode roll (2) is rotated in this state to perform seam welding of the flange portion C. I did it like that.

According to the present invention, the wrist (9) having a three-axis structure that supports the chucking device (8) that grips the fuel tank A is
Robot a with the ability to move in any direction dimensionally
The robot (lG) shown in the figure is a robot main body that can freely rotate around a vertical rotation axis (11a). A first arm ab extending forward is attached so as to be swingable in the vertical direction about a horizontal swing axis (12a) at the rear thereof, and a second arm ab extending downward is attached to the first arm 0z.
The arm (131 is connected to the horizontal swing axis (13a) at its upper end)
It consists of a base () that can swing freely in the front and rear directions around the robot body t'+i+.
is mounted on the upper surface of the aircraft (1), and the second arm a
The wrist part (9) is attached to the lower end of the robot body 3, so that the wrist part (9) can be moved in any three-dimensional direction by combining the movements of the robot body at and both arms (IZ G3). The robot main body surface was rotated via a bevel gear (11C) by a motor (11b) provided on the base 0@, and each arm (13 (13) was connected to the first arm 0@ The second
Each motor (12bH13
b), it is swung via a chain (not shown) that is strung between each swiveling shaft (12a) and (13a). In the drawing, (15a) indicates a link provided between the base a9 and the main body 11) in parallel with the extension.

In the above embodiment, both arms (IZ (13) are configured as swing arms, but the first arm 0 is movable forward and backward with respect to the robot body at, and the second arm Of course, a Cartesian coordinate type arm mechanism may be configured so that the arm mechanism can move up and down in the vertical direction, and a 3-axis Cartesian coordinate type robot may also be configured by making the robot body (11) slidable in the horizontal direction. good.

The wrist part (9) is connected to the wrist body (lG) attached to the lower end of the second arm a3 by a motor (17a).
4 - rotating shaft (17) rotated via bevel gear (iyb)
1 is provided, and a cross joint a& is attached to this.
The details are as shown in Fig. 3, and the rotating shaft (171
One mutually orthogonal shaft (18b) of the cross joint ae is supported by a fixed yoke (18a) integrally formed on the lower end of the yoke, and a movable yoke (18d) is supported by the other shaft (18c). The chucking device (8) is attached to the chucking device (8), and the fuel tank A gripped by the chucking device (8) can be moved into any three-dimensional position by moving around these three axes (17), (18b), and (18c). I made it possible to do so.

The wrist main body Oe is maintained in a constant posture even by the swinging of both arms (121 (13)) by a belt-type or other parallel ruler mechanism (not shown) provided along both arms (121G3), The rotating shaft q7 supported on this
) is now always kept vertical.

The chucking device (8) includes a gripping tool (8a) that grips the filler port d of the fuel tank A, and a pair of suction pads (8b) that grip the outer surface of the tank A.

Next, to explain its operation, with the fuel tank A gripped by the chucking device (8), the flange portion C is placed at a proper position on the lower electrode roll (3), and then the upper electrode roll (2) is lowered. After sandwiching the flange portion C between both electrode rolls (2) (3), the upper type electrode roll (2)
At the same time, the robot main body 01) and both arms (IZ (131) are operated to move the wrist (9) according to a pre-cheered three-dimensional trajectory, and the wrist (9) +7) 3-axis ( 171 (18b) (18
The attitude of the fuel tank A is changed three-dimensionally by the movement of c), and the flange portion C is continuously fed between the electrode rolls (2) and (3) as shown in FIGS. 3 to 5. Incidentally, during this welding work, cooling water is applied to the fuel tank A via a water supply pipe (not shown) in order to suppress the occurrence of thermal distortion in the fuel tank A.

By the way, in reality, both electrode rolls (2) (3) are determined by the feeding speed of fuel tank A and the rotation of upper electrode roll (2).
Due to various factors such as poor synchronization with the retraction speed of the flange portion C between the two electrodes and thermal distortion during welding, the double electrode roll (2)
(3) The direction of movement with respect to the flange portion C may deviate from the regular welding line, and it is desirable that the operator be able to correct this as appropriate.

In this case, the fuel tank A is connected to both electrode rolls (2) and (3).
For example, the wrist part (9) parallel to the vertical axis X connecting the centers of
The two electrode rolls (2) are rotated by rotation of the rotation axis a force.
Even if an attempt is made to correct the direction of travel in (3), the flange portion C is sandwiched between the electrode rolls (2) and (3), so the fuel tank A is not rotated, and in the end, the direction of travel cannot be corrected effectively. To do this, the fuel tank A is attached to both electrode rolls (2
) In contrast to (3), it is necessary to rotate around the axis X.

Therefore, in the above embodiment, the robot (9) is mounted on the body (1) so that the rotation axis (11a) of the robot body (11) coincides with the axis X, and the robot body at is simply rotated. The direction of travel was corrected so that it could be obtained.

Note that if the rotation axis (11a) does not match the axis A is not rotated about the axis X, and it is actually very difficult for the operator to make these movements by operating the control device.

In the above embodiment, the robot aO is connected to both electrode rolls (2) (3).
), but the same effect can be obtained by making both electrode rolls (2) <3) pivotable about the axis X.

(Effects of the Invention) As described above, according to the present invention, the wrist portion of the three-axis structure grips the workpiece through the chucking device, and the three-axis gripping device grips the workpiece.
In addition to making it possible to perform dimensional posture control, the wrist part can be freely moved in any three-dimensional direction by the robot, so that it is possible to perform three-dimensional movement control of the workpiece, Even if the welded part of the workpiece has a three-dimensionally curved shape, the welded part can be sequentially fed between a pair of electrode rolls of the seam welding machine to automatically and efficiently perform seam welding. Since the robot is mounted on the body of the seam welding machine, the installation space is sufficient for the seam welding machine, which is advantageous in terms of effective use of factory space. It also prevents harmful effects such as rust from scattering onto the robot.
This has the effect of improving the durability of the robot.

[Brief explanation of drawings]

Fig. 1 is a side view of an example of a seam welding machine equipped with the device of the present invention, Fig. 2 is an enlarged side view of its main parts, and Figs.
The figure is a perspective view of the main parts to explain its operation. (1) ... Machine body (2) (3) ... Electrode roll (8) ... Workpiece gripping device (9) ...
Wrist part (I■...Robot and 2 other people)

Claims (1)

[Claims] This is a workpiece guide device that feeds the welded part of a workpiece between a pair of electrode rolls provided in a seam welding machine, and has a three-axis wrist portion that supports a chucking device that grips the workpiece.
1. A work guiding device for a seam welding machine, characterized in that a robot capable of moving in any dimensionally direction is mounted on the body of the seam welding machine.