JPH024794Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a stud welding robot.

Prior Art Recently, there has been a strong tendency to use welding robots in the field of stud welding to save labor. By the way, conventional stud welding robots generally have a welding gun attached to the tip of the arm via an air cylinder or the like to absorb the shock when the pressing force of the gun momentarily becomes excessive.

For this reason, the structure of the gun mounting part becomes complicated.
Furthermore, the robot cannot be stopped immediately by absorbing a large shock from a direction other than the direction in which the gun is pressed, and has the disadvantage that there is a very high risk of damage.

Summary of the invention The present invention has been made to eliminate these drawbacks, and has a simple structure that can automatically stop the operation of the robot when excessive gun pressing force is applied. The object of the present invention is to provide a new and extremely useful stud welding robot that can absorb the shock and automatically stop the operation of the robot even when a large external force is applied from another direction.

In other words, the stud welding robot of the present invention is
In order to achieve the above object, a welding gun is attached to the tip of the arm of a stud welding robot so that it can move forward and backward in the pressing direction and in the opposite direction, and can swing freely, and a spring is used to bias the gun in the pressing direction. a limit switch that is provided with a spring to prevent the gun from swinging, and is activated to stop the operation of the welding robot when the gun travels a certain distance in the opposite direction or more; and a limit switch that is activated when the gun swings. The gist is that a limit switch is provided to stop the operation of the welding robot.

Disclosure of Embodiments Embodiments will be described in detail below based on the drawings.

FIG. 1 is a cross-sectional view of a main part showing an embodiment of a gun mounting device which constitutes a main part of the welding robot of the present invention.
Here, 1 is an arm of a stud welding robot having a rotatable wrist part 2 at the tip, 3 is a gun having a handle part 4, 5 is a guide shaft for moving the gun 3 forward in the pressing direction and the opposite direction, and 6 is a guide shaft. A spring that biases the gun 3 in the pressing direction; 7 a connecting pin that irremovably connects the guide shaft 5 to the wrist portion 2; 8 a spring that restrains the gun 3 from swinging; 9 and 10 are limit switches. be.

That is, in this embodiment, by fitting the upper end of the handle portion 4 of the gun 3 onto the guide shaft 5 located above the center line of the gun 3, the gun 3 can be moved in the pressing direction A and the opposite direction B. The gun 3 is always biased in the pressing direction A by a spring 6 stretched between the upper spring seat 11 of the guide shaft 5 and the upper end of the handle 4.

This spring 6 has a spring force sufficient to cope with the instantaneous repulsive force received from the workpiece during stud welding, and can sufficiently absorb fluctuations in the relative distance of the gun 3 to the workpiece. A limit switch 9 is installed inside the outer cylinder 12 that covers the guide shaft 5.
By providing a
When the welding robot moves beyond a certain distance, the handle 4 of the gun 3 operates a limit switch 9, which sends a stop signal to a control circuit (not shown) to automatically stop the operation of the welding robot.

On the other hand, the wrist portion 2 at the tip of the arm 1 has a substantially E-shaped cross section as shown in the figure, and by covering its outer periphery with an outer cylinder 13, a donut-shaped hollow portion 14 is formed inside. Furthermore, a plurality of pin insertion holes 16 and a flat, shallow conical bearing recess 17 are provided in the bottom wall 15 of the wrist portion 2.

Then, the pointed conical protrusion 18 at the upper end of the guide shaft 5 is loosely fitted into the bearing recessed hole 17 of the wrist portion 2, and the connecting pin 7 is loosely fitted into each pin insertion hole 16 to guide its lower end. Upper spring seat 11 of shaft 5
By screwing and fixing the guide shaft 5 to the wrist part 2, and by tensioning the spring 8 between the connecting pin head which can protrude into the hollow part 14 and the bottom wall 15, the guide shaft 5 can be prevented from falling off from the wrist part 2. They are connected to each other so that they can swing freely using the conical protrusion 18 as a fulcrum. However, since this oscillation is restrained by the spring 8, it does not occur under normal conditions, and only occurs when a large external force is applied from a direction other than the direction in which the gun is pressed, in the direction in which that external force is applied. be. A plurality of limit switches 10 are installed at appropriate locations within the hollow portion 14 of this wrist portion 2.
By bringing the detection parts of these switches 10 into contact with the upper spring seat part 11 of the guide shaft 5 as shown in the figure, external forces applied to the gun 3 in all directions can be detected. When the welding robot 5 swings together with the gun 3, these limit switches 10 are activated and send a stop signal to a control circuit (not shown) to automatically stop the operation of the welding robot.

Effects of the invention In the stud welding robot configured as described above, the gun 3 having the stud is moved in the pressing direction A.
When moving the stud to the workpiece,
The handle part 4 of the gun 3 is aligned with the guide shaft 5 in the opposite direction B.
Since the spring 6 is compressed by the movement, the stud can be pressed against the workpiece with sufficient pressing force while absorbing the shock pressure when pressing the stud.

Moreover, by providing the limit switch 9, if the shock pressure exceeds a certain value due to changes in the position of the workpiece, etc., the gun 3 and its handle 4 will be moved in the opposite direction B.
If the welding robot moves more than a certain distance, the limit switch 9 sends a stop signal to the control circuit and automatically stops the operation of the welding robot, so the gun mounting device is not damaged and is extremely safe. be.

Further, the gun 3 can swing freely together with the guide shaft 5, and the spring 8 normally prevents the gun 3 from swinging, so that, for example, the gun 3 may be pressed diagonally against the welding surface of the workpiece. Even if an external force is applied in a direction other than the direction in which the gun is pressed,
The gun 3 and guide shaft 5 swing in the direction of the external force to absorb the shock, thereby sufficiently preventing damage.

Moreover, when such a swinging motion occurs, the other limit switch 10 detects this and automatically stops the operation of the welding robot.
There is no possibility that the stud will be welded diagonally to the welding surface of the workpiece. Furthermore, compared to the conventional case where a shock absorbing means such as an air cylinder is used, the welding robot of the present invention has a gun mounting device that utilizes the force of springs 6 and 8.
The structure is simple and can be downsized, and manufacturing costs can also be reduced.

As described above, the stud welding robot of the present invention has a simple structure, can sufficiently absorb shock pressure from various directions, and can automatically stop the stud welding process when abnormal shock pressure is applied, making teaching work easier. It is also extremely easy to use, and has great practicality.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of an embodiment of a welding gun mounting device, which is a main part of the present invention. 1... Arm, 2... Wrist part, 3... Welding gun, 5... Guide shaft, 6, 8... Spring, 7... Connecting pin, 9, 10... Limit switch.

Claims (1)

[Scope of utility model registration request] A welding gun is attached to the tip of the arm of the stud welding robot so that it can freely move forward and oscillate in the pressing direction and the opposite direction, and includes a spring that biases the gun in the pressing direction and a spring that biases the gun in the pressing direction. A limit switch is provided, which is provided with a spring to stop the welding robot, and is activated to stop the operation of the welding robot when the distance of movement of the gun in the opposite direction exceeds a certain level, and a limit switch is activated to stop the operation of the welding robot when the gun swings. A stud welding robot equipped with a limit switch to stop the welding.