JPH0230383A - Welding robot - Google Patents

Abstract

PURPOSE:To improve working efficiency of welding and to reduce welding cost by providing power receiving connectors respectively to plural welding guns and arranging feeding connectors to the tip of a robot arm to perform welding by a shared welding transformer. CONSTITUTION:The single welding transformer 18 sharable for the plural welding guns 17 and 17 is set up in the vicinity of a welding robot main body 3. A tool changer 19 to change and hold the welding guns 17 and 17 is fitted to the tip of the robot arm 4 and a cylinder base 20 is arranged thereto. Air cylinders 23 and 24 to operate first and second feeding connectors are then provided to the lower part of the base 20 and the respective feeding connectors are made connectable to the power receiving connector 46 and 47. By this method, the single shared transformer 18 is connected to both guns 17 which can perform welding respectively. Since an interference at the time of welding is solved by omitting wiring, working efficiency of welding is improved and welding cost is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a welding robot used to integrally weld together a floor panel (underbody) and a side panel, for example, in an automobile body assembly process.

(Prior art) Conventionally, the assembly process of an automobile body generally includes a first process of assembling the floor panel, a second process of temporarily welding the side panel to the floor panel, and an additional process of welding the temporary welded panels. A third step of welding the two panels together is provided, and in this third additional welding step, means are taken to replace the welding gun depending on the shape of the bow and the day.

Conventionally, as a welding robot that replaces the above-mentioned welding gun, there is, for example, a robot described in Japanese Patent Application Laid-Open No. 62-21471.

That is, the welding robot is provided with a robot arm that holds a plurality of welding guns in an exchangeable manner, and can be attached to and detached from arbitrary welding guns in accordance with various shapes of automobile bodies.

However, in this conventional robot, each welding gun is equipped with a welding transformer, so the wiring between the multiple welding guns and each transformer interferes with the robot arm, resulting in a narrow welding work area. In addition, since multiple transformers and wiring are required, the cost of the robot is high.

(Purpose of the Invention) This invention has a unique structure in which power is supplied to each welding gun from a single welding transformer shared by multiple welding guns, thereby eliminating the need for each welding gun to have a separate welding transformer. , prevent interference between the wiring and the robot arm,
The objective is to provide a welding robot that can expand the welding work area and significantly reduce costs.

(Structure of the Invention) The present invention is a welding robot equipped with a robot arm that grips a plurality of welding guns interchangeably, and a single welding transformer shared by the plurality of welding guns is provided in the robot work area. On the other hand, each of the plurality of welding guns is provided with a power receiving connector connected to an electrode, and the tip of the robot arm is provided with a power feeding connector that supplies secondary power of the welding transformer to the power receiving connector of the plurality of welding guns. It is characterized by being a welding robot equipped with

(Effects of the Invention) According to the present invention, by electrically connecting the power receiving connector of the welding gun to the power supply connector provided at the tip of the robot arm, the above-mentioned power can be transmitted from a single welding transformer provided within the robot work area. Transformer secondary power can be supplied to the electrodes via the power supply connector and power reception connector.

As a result, there is no need to provide an equivalent welding transformer for each of the welding guns mentioned above, and the conventional wiring between the transformer and gun can be omitted.Therefore, there is no interference between the wiring and the robot arm, and therefore the welding work area This has the effect of increasing the number of people.

In addition, a single welding transformer shared by each welding gun,
Since welding can be carried out using only the wiring related to the transformer, it is possible to significantly reduce costs compared to the conventional robot described above.

(Example) An embodiment of the present invention will be described in detail below based on the drawings.

The drawings show a welding robot, and in Figures 1 and 2,
This welding robot 1 is placed, for example, at a car body retouching process station, and a robot body 3 is placed on a base 2 serving as a robot mounting base.
A robot arm 4 is attached to the upper part of the robot arm 4, which extends horizontally in the normal state.

The welding robot 1 described above also has a first shaft 5 that rotates the robot body 3 in the direction of the arrow a, a second shaft 6 that rotates the robot arm 4 in the direction of the arrow a, and a second shaft 6 that rotates the robot arm 4 in the direction of the arrow a.
A third shaft 8 that rotates the wrist portion 7 at the tip in the direction of arrow C, and a first wrist (vrist) 9 of the wrist portion 7 shown in FIG.
The fourth shaft 10 rotates the wrist in the direction of arrow d, and the second
A fifth axis 12 rotates the wrist 11 in the direction of the arrow e, and a sixth axis 1 rotates the third wrist 13 of the wrist portion 7 in the direction of the arrow f.
4, which has at least 66 degrees of freedom, and grips each welding gun 17, 17 on the left and right welding gun mounting stands 15, 16 in an exchangeable manner.

In the robot work area of the welding robot 1, for example near the side of the robot body 3, as shown in FIGS. 1 and 2, a single welding transformer 18 shared by the plurality of welding guns 17 and 17 is installed. ing.

By the way, as shown in FIGS. 3 to 6, a tool changer 19 for removably holding a plurality of welding guns 17 and 17 is attached to the tip of the third wrist 13, and one side of this tool changer A vertically rectangular cylinder base 20 is fixed to the cylinder base 20.

Then, on the lower back side of this cylinder base 20, a first
and a first operating each second power supply connector 21,22.
The air cylinder 23 and the second air cylinder 24 are mounted in parallel with each other with a slight vertical separation.

Further, conductive blocks 27.28 are fixed to the piston rods 25, 26 (see Fig. 7) of the above-mentioned area cylinders 2, 3.24, and the above-mentioned welding Secondary cables 29 and 30 in the transformer 18 are connected separately.

Furthermore, a third air cylinder 32 for operating a water supply unit 31 for cooling the welding gun is attached to the upper rear surface of the cylinder base 2o, and the water supply unit 31 is attached to the tip of the piston rod 33 of the third air cylinder 32. In addition, a water supply hose 34 is connected to the P boat of this water supply unit 31, and a return hose 35 is connected to the main T boat.

On the other hand, the aforementioned welding gun 17 has one electrode tip 39 attached via a gun arm 38 to a gun body 37 equipped with a pressurizing device 36, and is operated to apply pressure to the aforementioned gun body 37 via an equalizer 40. The other electrode tip 41 is attached, and these upper and lower electrode tips 41 and 39 are opposed to each other.

Further, an insert head 42 is attached to the back surface of the gun body 37 described above, and the insert head 42 is held exchangeably by the tool changer 19 described above.

Furthermore, a lower bracket 43 is attached to the lower part of one side of the gun body 37, and terminals 44 and 45 are attached to the inner surface of the extended portion of the lower bracket 43 at a distance from each other vertically. , 45 has the first
and second power receiving connectors 46, 47 are provided, and each of these power receiving connectors 46, 47 is connected to each of the above-mentioned power feeding connectors 21.
It is facing 22.

Furthermore, a gun-side cable 50.51 is connected between each terminal 44.45 and the conductive terminal 48.49 on each electrode chip 41.39 side.

On the other hand, a joint unit base 54 is attached to the top deck of the gun body 37 through an inverted upper bracket 52 and a gusset 53, and a joint unit base 54 is attached to the part of the joint unit base 54 that faces the water supply unit 31. The joint unit 55 is installed.

A water supply hose 56 is attached to the A boat of this joint unit 55, and a return hose 57 is attached to the Marari boat.
are connected to each other.

Incidentally, FIG. 7 is a system diagram schematically showing the above-mentioned configuration, and in the figure, reference numerals 58 and 59 indicate primary side gaples of the welding transformer 18.

The illustrated embodiment is constructed as described above, and its operation will be explained below.

The above-mentioned welding robot 1 controls the rotation of the robot arm 4 in accordance with the shape of the automobile body in the additional welding process of the automobile body, and selects one of the left and right welding guns 15 and 17. The selected welding gun 17 is gripped by the tool changer 19 at the tip of the third wrist 13.

After gripping the above-mentioned welding gun 17, the first, second and third air cylinders 23, 24.32 are driven to move the respective piston rods 25, 26, 33 forward, and the first power supply is activated. connector 21 and first power receiving connector 46,
The second power supply connector 22 and the second power reception connector 47, the water supply unit 31 and the joint unit 55 are connected, respectively, and the secondary power of the welding transformer 18 is supplied to the power reception connector 46, 47 of the welding gun 17, Cooling water is supplied to the cooled portion of the welding gun 17, for example, the inner cavity of the metal tip.

For this reason, when the additional parts of the floor panel and side panel of an automobile body are held and pressurized with a pair of electrode tips 41°39, the above-mentioned panel is It can be heated, brought to a molten state, and then spot welded by applying pressure.

In this way, by electrically connecting the power receiving connector 46.47 of the welding gun 17 to the power supply connector 21.22 provided at the tip of the robot arm 4, a single welding transformer 18 provided within the robot work area can be connected. Since the transformer secondary power can be supplied to the electrode tips 41 and 39 of the welding guns 17 through the above-mentioned power supply connectors 21 and 22 and the power reception connectors 46 and 47, the plurality of welding guns 17 described above can perform equivalent welding. There is no need to provide a transformer, and the conventional wiring between the transformer and the gun can be omitted.

As a result, there is no interference between the wiring and the robot arm 4, and the welding work area can be expanded.

In addition, the above-mentioned welding can be performed using only the single welding transformer 18 shared by each welding gun 17 and the wiring related to the transformer 18, that is, each cable 29, 30, 50, 51.58° 59. Therefore, compared to conventional welding robots, it has the effect of significantly reducing costs.

In the correspondence between the structure of this invention and the above-described embodiments, the electrode of this invention corresponds to the direct welding type electrode tip 39, 41 of the embodiment, and similarly, the power supply connector has the first and second electrode tips 39 and 41 of the embodiment. Each power supply connector 21
．． 22, the power receiving connectors are each of the first and second power receiving connectors 46.
．． However, the present invention is not limited to the configuration of the above-described embodiment.

In addition, although the above embodiment exemplifies spot welding in the additional welding process for automobile bodies, it may also be applied to robots that perform spot welding, multi-spot welding, or other electric resistance welding on other workpieces. Of course.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a schematic side view of a welding robot, FIG. 2 is a schematic rear view of the welding robot, and FIG. 3 is a plan view showing the robot with a welding gun gripped at its wrist. Figure 4 is a side view of the main parts of Figure 3, Figure 5 is a side view showing the separated state of the robot wrist and welding gun, Figure 6 is a plan view showing the joint structure of the cooling water unit, FIG. 7 is a system diagram of the electrical system and cooling water system of the welding robot. 4... Robot arm 17... Welding gun 18.
...Welding transformer 21...First power feeding connector 22...Second power feeding connector 39.41...Electrode chip 46...First power receiving connector 47...Second power receiving connector, evening

Claims (1)

[Claims] (1) A welding robot equipped with a robot arm that grips a plurality of welding guns interchangeably, wherein a single welding transformer shared by the plurality of welding guns is provided in the robot work area; Each gun is provided with a power receiving connector connected to an electrode, and a welding robot is provided with a power feeding connector that supplies secondary power of the welding transformer to the power receiving connectors of the plurality of welding guns at the tip of the robot arm. .