JPS62114776A - Tip cleaning method for arc welding machine - Google Patents

Abstract

PURPOSE:To prevent the adhesion of the spatter at the torch tip part and to increase the operation rate of a welding robot by cleaning the torch tip part by a shot blasting device on each one work stage. CONSTITUTION:A welding robot stops at the position of a shot blasting device 3 after completion of the welding of a work and the torch tip part 6 is inserted into the opening part 14 of the upper lid 13. In the cleaning stage, then, circuits 31, 34 become the circuit that compressed air is communicated by the operation of a changing valve 32 and the compressed air is exhausted from the nozzle pipe 15 just under the torch tip part 6. The shot ball 22 of the metallic small granule inside a case 12 is sucked to a nozzle cover 21 from the opening part 20 and spouted for the torch tip part 6 from the opening part 19 of the cover 21. The removal of the spatter adhered to the tip cover 28, tip 25 and core wire 26 of the torch tip part 6 is performed by the impact action of the shot ball 22. This spatters removal is performed repeatedly by the changeover of the circuit while under the welding stage.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for removing spatter that is generated when a workpiece, which is a metal base material, is rear-arc welded by a robot and adheres to the tip of a torch during the welding process.

Prior Art As a method for preventing spatter from adhering to the tip of the torch that occurs during conventional arc welding, the first example is as shown in Japanese Unexamined Patent Publication No. 60-61181. The second method is to immerse the torch in oil to coat the inner wall of the torch nozzle with an oil film, and after welding, inject high-pressure air into the torch through a switching valve installed in the equipment to remove spatter that has adhered to the inside of the torch nozzle. As an example, as shown in Japanese Utility Model Application Publication No. 48-12323, a nozzle made of aluminum alloy, which has poor heat and shock resistance, is screwed onto the tip of the torch, and metal splashes from the molten welding rod are attached to the tip of the nozzle. It is known that the structure makes it difficult to adhere to the parts.

Problems to be Solved by the Invention In the first example of the conventional method described above, the tip of the torch is coated with an oil film to help prevent adhesion of spatter. This is difficult and cannot be said to be a sufficient method, and the second example requires time and effort to replace the tip at the tip of the torch or the nozzle, and is made of a special aluminum alloy material. Therefore, neither of the above methods is sufficient for removing spatter or preventing adhesion, and it takes a considerable amount of cleaning time to remove and clean the torch. There was a drawback that it was necessary. Therefore, in the arc welding process using a welding robot, there is no need to remove and clean the torch tip. Cleaning is performed during each welding process, and the gas atmosphere at the torch tip is maintained. There was a need for a cleaning system with good workability that could prevent deterioration in welding quality such as weld bead displacement or arc breakage, poor melting, or oxide entrainment, and improve operation rates.

In view of the above-mentioned prior art, the present invention installs a shot blast type torch tip cleaning system in the arc robot welding process, and in the welding process, a worker cleans the torch tip after each work process, This invention was invented for the purpose of providing a method for cleaning the tip of an arc welding machine, in which standby, welding, and cleaning operations are performed sequentially according to a program, thereby improving welding quality and the operation rate of the welding process.

Means for Solving the Problems The present invention, as described in the claims, involves inserting the torch tip downward into the shot blasting device each time a predetermined arc welding process is completed, and inserting the torch tip into the shot blasting device at the bottom of the shot blasting device. Compressed air is ejected toward the tip of the torch, and the jet of compressed air causes a shot of small metal particles to collide with the chip cover, chip, and core wire at the tip of the torch, removing spatter, and then removing the spatter from the tip of the torch. By repeating this process with the process of returning to the welding position, the chip is cleaned with a shot after each operation in the arc welding process using the robot, improving welding quality and reducing the robot's operating rate. This is to enable improvements to be made.

Examples and operations FIGS. 1 and 2 show embodiments of the method of the present invention.
FIG. 2 is a layout diagram of a device showing an embodiment of a method for cleaning spatter attached to a tip of an arc welding machine, in which a workpiece 2, which is a metal base material, and a shot blasting device 3 are located within the motion trajectory of a welding robot 1. The welding robot 1 is shown in FIG.
The arm 5 has a multi-joint structure, and is operated between two positions: the origin position A of the movement of the arm 5, shown by a solid line in the figure, and the welding position B of the workpiece 2, shown by a two-dot chain line, and between the above-mentioned position B. The shot blasting device 3 has a structure in which it can be freely raised and lowered, rotated, moved in the front and rear directions, and stopped between two positions, namely, the rotating position indicated by the dashed arrow and the position C of the shot blasting device 3 indicated by the two-dot chain line. The power source of the robot 1 is equipped with a servo motor, etc., and is arranged so that the robot 1 can perform the above-mentioned operations on the workpiece 2 and the shot blasting device 3 according to a predetermined program in the welding process. In addition, a power cable 9 and a conduit tube 8 are disposed along the arm 5 toward the tip of the robot 1, and the ends of both are disposed at the tip of the arm 5. The other end is connected to a gas source, a power source, etc., and the gas, current, and welding rod are continuously supplied to the tip 7 of the torch tip 6, which will be described later. It is arranged so that the workpiece 2 can be continuously welded.

The workpiece 2 is not limited to a workpiece set on the workbench 10, but when welding a workpiece set on a moving conveyor, there is no problem as long as the conveyor is placed within the trajectory of the operating range of the robot 1. .

FIG. 1 is a sectional view showing the outline of the structure of the shot blasting device 3 used in the embodiment shown in FIG. Each part constituting the nuclear device 3 will be explained below.

The case 12 is integral with the bottom and has a cylindrical shape, and is placed on the stand 11 shown in FIG.
A is opened, and a nozzle pipe 15 is provided protruding from the bottom surface of the case 12 toward the center position of the opening 14, and the tip of the pipe 15 is located at a position opposite to and adjacent to the torch tip 6. and the other end of the lower part is case 12.
It is connected to a pipe 17 disposed on the outside of the bottom surface of the tank via a joint 18 for preventing backflow of balls, and communicates with a compressed air circuit.

Further, an opening 19 is provided at a position above the tip of the nozzle pipe 15 surrounding the nozzle pipe 15, and an opening 20 serving as a narrow suction port with an annular cross section is provided at the lower end. A nozzle cover 21, which is integral with parts 19 and 20, is attached to the case 12.
A discharge flow path 23 for the shot balls 22, which are small metal particles, in the case 12 is provided protruding from the bottom of the torch toward the torch tip 6, and is arranged to be co-centered with the nozzle pipe 15.
is formed.

On the other hand, a tip 25 is screwed onto the base 24 of the torch tip 6 inserted into the upper lid 13.
A through hole is arranged in the center of the tip 2 so that a core wire 26, which is a wire-shaped welding rod, is continuously fed out to the torch tip 6, and a shield gas discharge port 27 is provided at the base of the tip 2 with a radius the chip 25
A cylindrical tip cover 28 with an open tip surrounding the tip is fixed to the base 24, and the tip force bar 28 provides a flow path 2 for shielding gas discharged from the gas discharge port 27.
9 is formed.

A switching valve 32 and a pressure reducing valve 33 are disposed in a circuit 30.31 that communicates with the torch tip 6 and the shot blasting device 3 and serves as a flow path for shielding gas and compressed air. A circuit 31 connected to the boat on the outlet side of the pressure reducing valve 33 connects to the base 2 of the torch tip 6.
4 and communicates with the gas discharge port 27 and the flow path 29 to form a compressed air circuit used for cleaning the rolled gas or the torch tip 6. The circuit 30 connected to the port is connected to the piping 17 on the lower side of the case 12, communicates with the nozzle pipe 15 via the joint 18, and is formed as a circuit for compressed air during cleaning. Sometimes it is sucked in from the tip of the nozzle pipe 15 or from the opening 20, and at the opening 19 of the nozzle cover 21, it is accelerated by the compressed air and forms a jet, and the tip 25, which is the tip of the torch tip 6, and the tip cover 28 It is formed in a structure that gives an impact to the object.

As shown in FIG. 2, the robot l is rotated from the origin position A of the welding robot 1 as shown in FIG. −
1, the workpiece 2 is welded at the welding position B, and when the welding work is completed, the robot 1 is rotated to the position C of the shot blasting device 3, and the tip cover 28, the tip 25. The spatter attached to the core IJ26 is removed and the welding process is completed. Next, the robot 1 returns from the origin position A to the welding position B of the workpiece 2, welds the next workpiece 2, and cleans the torch tip 6, which are repeated every time the welding process is completed. It is designed to remove the adhesion of - The shot blast type chip cleaning method shown in the embodiments described above will be explained with reference to FIGS. 1V and 2. After the welding of the workpiece 2 is finished, the welding robot 1 stops at position C of the shot blasting device 3, and when the torch tip 6 is inserted into the opening 14 of the upper cover 13 of the shot blasting device 3, the cleaning process begins. The circuits 31 and 34 become circuits through which compressed air is communicated by the operation of the switching valve 32. For example, compressed air of 5 kg/cr& is released from the nozzle pipe 15 directly below the torch tip 6, and serves as the suction port of the nozzle cover 21. As mentioned above, the torch tip 6 is removed from the opening 19 of the nozzle cut 21 by the action of compressed air.
Tip cover 28 and tip 25 of the torch tip 6 facing toward
, the spatter attached to the core wire 26 is removed, and at the same time the pressure is reduced by the pressure reducing valve 33, for example, 2 kV/cλ.
The compressed air passes through the circuit 31 to the shield gas outlet 27
The spatter that is emitted from the tip of the tip cover 28 through the flow path 29 and attached to the torch tip 6 is forced to adhere to the tip by the compressed air circuit of the Yottoplast device 3 and by the impact of 2. The removal of spatter is repeatedly performed by switching circuits during the welding process.

Also, during welding work on the workpiece 2, the switching valve 32 switches the circuit 31 to a 7-gate gas circuit, and the discharge port 27
Is the welding quality for workpiece 2 more shielding gas released? maintain.

The circuit 34 is closed by the switching valve 32 so that no compressed air can be discharged. Of course, during the welding operation, the torch tip 6 is separated from the shot blasting device 3 by the operation of the welding robot 1, and is placed at the welding position B shown in FIG.

Effects of the Invention In the method of the present invention, the tip of the torch is cleaned for each work step in the welding process using the apparatus having the structure explained above, and each of the rotation, standby, welding, and cleaning operations of the welding robot is performed. During the welding process, the welding process is carried out according to the initial program, and there is no adhesion of spatter on the torch tip.Therefore, there is no problem with the shielding gas flow, which has the effect of eliminating abnormalities in welding quality. This eliminates the need to remove parts, improves welding work, and increases the operating rate of welding robots.

[Brief explanation of drawings]

FIG. 1 is a schematic longitudinal cross-sectional view of an example of a yacht blasting apparatus used in carrying out the present invention, and FIG. 2 is a layout diagram showing an outline of the operation of an example of an embodiment of the present invention. 3 / Yotsuto Plus)・device, 6 [-chi tip, 22
．． 7 Yonoto balls, 25 chips, 26 core wires, 28 chip covers.

Claims (1)

[Claims] At the end of each arc welding process, the torch tip is inserted downward into the shot blasting device, compressed air is jetted from the bottom of the shot blasting device toward the torch tip, and the jet of compressed air removes small metal particles. A method for cleaning the tip of an arc welding machine by repeatedly colliding a barrel shot ball with the tip cover, tip, and core wire at the tip of the torch to remove spatter, and then returning the tip of the torch to the welding position.