JPH0741577Y2 - Welding cable connection structure of spot welding robot - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to a welding cable connection structure for a spot welding robot.

b. Conventional technology Welding robots have welding electrodes as shown in Figs. 3 and 4.
A welding cable 103 is connected to a multi-joint robot arm 101 provided with 100 via bolts 102. Welding cable 103
Is a cable body 1 made of a stranded copper wire in a cylindrical outer tube 104.
05 is built in, and the terminals 106 of the welding cable for connecting to the robot arm 101 and the transformer (not shown) are attached to both ends. A cooling water pipe 107 is connected to the terminal 106 of the welding cable to cool the cable body 105.

c. Problems to be Solved by the Invention However, according to the prior art, the robot arm 101
Since the terminal 106 of the welding cable is fixed by the bolt 102, the welding cable 103 is twisted according to the movement of the robot arm 101.

Therefore, there is a risk that the welding cable 103 may bend due to a change in the posture of the welding robot, and the cable body 105 may be broken due to fatigue. Further, due to the bending, the flow of the cooling water becomes poor, and the current flowing at 10,000 amperes or more causes the cable body 105 to generate heat, which causes a break in the operation for several days due to fatigue and heat generation.

It is an object of the present invention to solve the above problems and to provide a welding cable connection structure for a spot welding robot, which can prevent the welding cable from being broken due to the bending resistance of the welding cable.

d. Means for Solving the Problems In order to solve the above problems, the present invention has a structure of a connecting portion of a welding cable for energizing a welding electrode of a welding gun of a spot welding robot, which is rotatable coaxially with each other. In addition, an electromagnet is placed at a position where a magnetic force acts relatively on the opposing planes of a pair of rotating terminals that are axially supported so that they can be moved toward and away from each other by a minute dimension, and the welding electrode of the welding gun synchronizes the action on the work Then, it is possible to control so that the pair of electromagnets attract each other and repel each other.

e. Action In the robot positioning process, the electromagnet is repulsed so that the electrodes are separated from each other. Then, the electrode terminals are freely rotated to position the welding electrode.

Next, in the welding process, when the electromagnet is attracted so as to bring the electrode terminals into close contact with each other, the electrode terminals are connected and the electrical connection is completed.

f. Embodiment Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a conceptual diagram showing a welding cable connection structure of a spot welding robot, wherein 1 is a multi-joint robot arm provided with a welding electrode 2, 3 is a welding cable connecting a welding electrode 2 and a transformer (not shown), and 4 is a welding cable. Articulated robot arm 1
Is a rotary connection portion provided between the terminal 5 of the welding gun and the terminal 6 of the welding cable 3 via bolts 7 and 8. The welding cable 3 is connected to the welding gun. This rotating connection 4
As shown in FIG. 2, the structure of is composed of a pair of rotating terminals 9 and 10 which are rotatable with respect to each other and are capable of coming into contact with and separating from each other in the axial direction, and an annular shape provided on the facing surfaces of these rotating terminals 9 and 10. Recesses 11,12
It is composed of electromagnets 13 and 14 installed inside. The electromagnets 13 and 14 are provided in the recesses 11 and 12 via a magnet holding spacer 15, and the lead wires 16 of the electromagnets 13 and 14 are connected to the electrode terminals 10.
Is connected to a control device (not shown) through the passage 17. The electromagnets 13 and 14 are an electric circuit in which a current flows so that the attraction force acts when the welding electrode 2 acts on the workpiece and the repulsion force acts at other times. This is immediately performed by using the welding control circuit. It is possible.

Connect the rotating terminals 9 and 10 to the center axis of the rotating terminals 9 and 10 through hole 1.
8 and 19 are bored, step portions 20 and 21 are formed on both sides of the through hole 18, and a bolt 22 is inserted from one side of the step portions 20 and 21 and tightened with a nut 23.

The nut 23 is inserted on the axis of a slide bearing 24 installed in the through hole 19 and is prevented from coming off by a retaining ring 26 attached to the tip of the bolt 22 via a damper 25.

A dustproof boot 27 is mounted on the outer periphery between the rotary terminals 9 and 10. 28 is a bolt hole through which the bolts 7 and 8 are inserted.

According to the above configuration, when the welding robot is moving to perform positioning, the electromagnets 13 and 14 repel each other to separate the rotary terminals 9 and 10 from each other.

Next, when entering the welding process, electric current is applied so that the electromagnets 13 and 14 attract each other, and the rotating terminals 9 and 10 are brought into close contact with each other.

g. Effects of the Invention As described above, the welding cable connection structure of the spot welding robot according to the present invention can achieve the following effects.

Since the electromagnet is used as the actuator, the mechanical sliding portion is small, and when welding is not energized, the energized surface is in non-contact, so the movement is smooth.

Further, since the current-carrying surface and the rotary sliding portion are separate, the current-carrying surface does not deteriorate and the current-carrying performance does not deteriorate.

Furthermore, since a welding control circuit is available, no special electric circuit is required.

As a related prior art, there is Japanese Utility Model Publication No. 61-21179.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a welding cable connecting structure for a welding robot of the present invention, FIG. 2 is a sectional view showing a rotary connecting portion of FIG. 1, and FIG. 3 is a welding cable for a conventional welding robot. FIG. 4 is a perspective view showing the connection structure, and FIG. 4 is a partial cross-sectional perspective view showing the welding cable of FIG. 1 ... Articulated robot arm, 2 ... Welding electrode, 3 ...
Welding cable, 4 ... Rotating connection, 5 ... Welding gun terminal, 6 ... Welding cable terminal, 9,10 ... Rotating terminal, 1
1,12 ... recess, 13,14 ... electromagnet.

Claims (1)

[Scope of utility model registration request] 1. A structure of a connecting portion of a welding cable for energizing a welding electrode of a welding gun of a spot welding robot, wherein a pair of shafts are rotatable coaxially with each other and axially supported so as to be capable of contacting and separating by a minute dimension. The electromagnets are arranged on the opposite planes of the rotating terminals of the position where the magnetic force acts relatively, so that the pair of electromagnets attract each other in synchronization with the action of the welding gun welding electrode on the work. Welding cable connection structure for spot welding robots, which can be controlled to repel.