JPH0312467Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a current-carrying joint used in a resistance welding device or the like.

Conventionally, as a type of resistance welding device, as shown in Fig. 1, a welding gun d is attached to the tip of a robot arm c of a robot body b placed on a pedestal a. A structure in which welding current is supplied from a power source e is known. f is the cable for this current supply,
g is an auxiliary cable, and this resistance welding device is configured to supply current to the welding gun d in a movable manner by bending each of the cables f and g.

However, in this type of structure, when spot welding is performed continuously on the same plane (marked by X in the figure) such as the tire house of a car h as shown in Fig. 2, the cable g has an extremely small curvature. There is a problem of wire breakage due to the repeated bending action. For this reason, as well as conventionally,
As shown in Japanese Patent No. 103375, a connector terminal has been devised in which a plurality of pairs of connector terminals are rotatably connected via a single support shaft and brought into close contact with each other. Since the sliding contact portions between the connector terminals are exposed to the outside,
There is a problem in that dust can easily enter the sliding contact portion, resulting in poor contact.

The present invention was made in view of the above problem, and is movable in accordance with the movement of the welding gun.
The purpose is to provide a current-carrying joint that prevents bending of the cable and extends its life, and is less likely to cause poor contact.To achieve this purpose,
a fixed terminal, a fixed plate fixed to the fixed terminal, a power feeding plate fixed to the fixed terminal and facing away from the fixed plate, and spaced opposing parts of the fixed plate and the power feeding plate coaxially with each other. formed 1
a pair of shaft insertion holes, a shaft rotatably inserted into the pair of shaft insertion holes, and a shaft insertion hole inserted between the spaced opposing portions of the fixed plate and the power supply plate, and into which the shaft is inserted. a movable terminal that is rotatable around the shaft; a recessed step formed in a part of the inner wall of the shaft insertion hole of the movable terminal; and a contact member in close contact with each of the movable terminals, a spring that presses the contact member, an insulating bushing interposed between the peripheral surface of the shaft and the inner wall of the shaft insertion hole of the power supply plate, and the shaft. and a thrust bearing interposed between the power supply plate and the movable terminal at the outer periphery of the contact member. , there is provided a current-carrying joint in which a current-carrying path via the power supply plate and the contact member is set between the fixed terminal and the movable terminal.

Hereinafter, one embodiment of the current carrying joint of the present invention will be described with reference to the drawings.

In FIGS. 3 and 4, reference numeral 1 indicates a fixed terminal in which a cable mounting bolt hole 1a is drilled, and above and below the left end of the fixed terminal 1, the right ends of the fixing plate 2 and the power supply plate 3 are provided with bolts. 4 and nut 5 are screwed together to securely hold the left end of the fixed terminal 1. A shaft insertion hole 2a that is concentric with the fixed plate 2 and the power supply plate 3 is located near the left end.
3a is bored, and a shaft 6 having a flange 6a at the upper end and a male screw portion 6b at the lower end is inserted therethrough.
7 indicates a nut screwed onto the male threaded portion 6b. Reference numeral 8 denotes a movable terminal having an insertion hole 8b for the shaft 6 drilled in a portion near the right end, and a hole 8a for a cable attachment bolt bored in a portion near the left end, with the shaft 6 as the center. , is configured to rotate relative to the fixed terminal 1 and the fixed plate 2 and power supply plate 3 fixed to each fixed terminal 1 within the range indicated by the upper arrow in FIG. The shaft insertion hole 8 of this movable terminal 8
On the inner circumference b, a ring-shaped recessed step 8c is formed at the distal end adjacent to the power supply plate 3, and a contact member 9 is inserted into the recessed step 8c. This contact member 9 has an outer circumferential surface having the same curvature as the inner circumferential surface of the recessed step portion 8c, a lower end surface that is perpendicular to the axis of the shaft 6, and an upper surface that is tapered toward the outer circumferential side. It is formed by dividing an annular member with an end surface into a plurality of pieces in the circumferential direction, and a plurality of springs 11 are applied via an annular pressure ring 10 having a tapered lower end surface corresponding to the tapered surface. The movable terminal 8 is pressed against the inner circumferential surface of the recessed step 8c and the upper surface of the power supply plate 3. 12 is an insulating spring holder, 13 is a bearing, 14 and 15 are insulating bushes, 1617 is a thrust bearing, and an insulating plate 18 is attached to the outer surface of the movable terminal 8.

In the current-carrying joint having the above configuration, the movable terminal 8, the power supply plate 3, and the fixed terminal 1 are made of a material such as a highly conductive copper alloy, and the contact member 9 is made of a silver-based material containing a lubricant. A current conduction path is formed from the movable terminal 8 to the fixed terminal 1 via the contact member 9 and the power supply plate 3. In order to maintain this path, predetermined members such as the thrust bearings 16, 17, bushes 14, 15, spring retainer 12, etc. are made of insulating material or are subjected to insulation treatment.

The above-mentioned current-carrying joint is connected to the auxiliary cable g and welding gun d of the resistance welding device shown in FIGS. 1 and 2.
When the movable terminal 8 is connected to the cable g side and the fixed terminal 1 is connected to the gun d side, as the gun d moves, the movable terminal 8
rotates relative to the fixed terminal 1 to suppress bending of the cable g as much as possible and prevent its breakage. The relative rotation angle of the movable terminal 8 with respect to the fixed terminal 1 is indicated by W in the figure.
By increasing the distance between the 8 and 8 to a certain extent, the gun expands over 270 degrees as shown by the arrow, allowing operation over a wide range of angles.
Considering the range of movement, it is desirable to take an angle of at least 180 degrees. In addition, when the movable terminal 8 rotates and comes into direct contact with the fixed terminal 1 as in this embodiment, an insulation treatment is applied to prevent direct electrical conduction between the two members 1 and 8. .
In this embodiment, an insulating plate 19 is provided at the corner of the fixed terminal 1.
I got 20.

As explained above, the current-carrying joint of the present invention has a movable terminal rotatably attached to a fixed terminal, and the relative rotational movement of both terminals prevents extreme bending of the cable and prevents disconnection of the cable. This can dramatically extend the lifespan of the cable. According to tests conducted by the inventors, a cable that would break at 120,000 dots (welding) with a conventional product was able to maintain more than 1 million dots under the same conditions. Further, the movable terminal is rotatably sandwiched between a fixed plate fixed to one end of the fixed terminal and one end of a power supply plate with a shaft, and other than the fixed terminal, the movable terminal is obstructed from rotating. Since there is no member, the rotation angle of the movable terminal can be increased, and from this point as well, bending of the cable can be prevented. Additionally, in the past, in order to bend the cable significantly, a considerable amount of force was applied to the wrist of the robot arm supporting the welding gun, which placed a heavy burden on the robot itself.
The current-carrying joint of the present invention suppresses the bending of the cable, which reduces the burden, and also prevents adverse effects such as displacement of the dot position due to this burden. In addition, the contact member that comes into close contact with the power supply plate and the movable terminal is placed inside the recessed part formed on the movable terminal, and this recessed part is isolated from the outside by an insulating bushing, a bearing, and a thrust bearing. Accordingly, poor contact between the contact member and the sliding contact portion of the power supply plate or the movable terminal can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a resistance welding device equipped with a robot, Fig. 2 is an explanatory diagram of its usage state, Fig. 3 is a front view of a current-carrying joint according to an embodiment of the present invention, and Fig. 4 is a side cross-section of the same. It is a diagram. 1...Fixed terminal, 2...Fixed plate, 3...Power supply plate, 6...Shaft, 8...Movable terminal, 2a, 3
a, 8b...shaft insertion hole, 8c... recessed step,
9... Contact member, 10... Pressure ring, 11...
Spring, 13... Bearing, 14, 15... Insulating bushing, 16, 17... Thrust bearing, 18,
19, 20...Insulating board.

Claims (1)

[Scope of utility model registration request] A fixed terminal 1, a fixed plate 2 fixed to the fixed terminal 1, a power supply plate 3 fixed to the fixed terminal 1 and facing away from the fixed plate 2, the fixed plate 2 and the power supply plate 3. A pair of shaft insertion holes 2a and 3a formed coaxially with each other in spaced opposing parts of the
and a shaft 6 rotatably inserted into the pair of shaft insertion holes 2a and 3a, and a spaced apart opposing portion of the fixed plate 2 and the power supply plate 3,
A movable terminal 8 that has a shaft insertion hole 8b through which the shaft 6 is inserted and is rotatable around the shaft 6, and a shaft insertion hole 8 of the movable terminal 8.
a recessed step 8c formed in a part of the inner wall of b; and a contact member 9 disposed within the recessed step 8c and in close contact with each of the power supply plate 3 and the movable terminal 8.
a spring 11 that presses the contact member 9; an insulating bush 15 interposed between the circumferential surface of the shaft 6 and the inner wall of the shaft insertion hole 3a of the power supply plate 3; a bearing 13 interposed between the inner wall of the shaft insertion hole 8b of the movable terminal 8; a thrust bearing 17 interposed between the power supply plate 3 and the movable terminal 8 on the outer circumference of the contact member 9; , the power supply plate 3 is provided between the fixed terminal 1 and the movable terminal 8.
and a current-carrying joint in which a current-carrying path via the contact member 9 is set.