JPH1158029A - Cooling device for spot welding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the exchanging work of an electrode part. SOLUTION: A channel R for feeding and draining cooling water is constituted to a welding machine, and cooling water passages 3A, 3B passing through electrode tips 2A, 2B are formed within a welding machine main body. Also, shut-off valves 9A, 9B and check valves 11A, 11B are provided in the vicinity of the welding machine main body in the middle of the channel R, and the shut-off valves 9A, 9B are closed when a current feeding circuit 13 to the welding machine is turned off. Therefore, only a small quantity of cooling water between the shut-off valves 9A, 9B and check valves 11A, 11B is leaked accompanied by the exchange of electrode tips 2A, 2B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for a spot welding machine.

[0002]

2. Description of the Related Art FIGS. 3 and 4 show the state of piping of cooling water for a conventional spot welding machine. The spot welding machine 20 has a pair of upper and lower electrode tips 21 and 22.
Are provided, and in order to perform cooling for these,
Two pipes S1 and S2 for water supply and two pipes E1 and E2 for drainage are connected to the spot welding machine 20, respectively. On the other hand, a cooling water passage T is formed inside the spot welding machine 20 so as to pass through the two electrode tips 21 and 22 and communicate with the pipes.
The cooling water is supplied and drained individually to the

[0003] Here, reference numeral 23 denotes a transformer for supplying power to the spot welding machine 20, and a water supply manifold 24 and a drain manifold 25 connected to a water supply / drain main pipe of a factory facility (not shown) are arranged on a side surface thereof. The water supply pipes S1 and S2 or the drainage pipe E
1 and E2 are connected.

[0004] A water stop valve 26 is interposed upstream of the water supply manifold 24. The water stop valve 26 is a three-way valve, and has a position for supplying cooling water to the cooling water passage T, and a drainage position for cutting off this supply and communicating with the air pipe 28 to supply air into the cooling passage T. Is set.
A check valve 2 is provided downstream of the drain manifold 25.
7 are interposed.

[0005] In the above configuration, when performing a normal welding operation, since the water stop valve 26 is held at the cooling water supply position, the cooling water flows through the cooling water passage T in the spot welding machine 20. The electrode tips 21 and 22 are cooled by this. When replacing the electrode tips 21 and 22, the water stop valve 26 is switched to the drain position. As a result, the supply of the cooling water is cut off and the air is introduced into the cooling water passage T through the air pipe 28, so that the cooling water accumulated in the spot welding machine 20 is discharged from the drain pipes E1 and E2. Is done.

Further, when performing the replacement work of the electrode tips 21 and 22, the power plug 29 is removed so that the spot welding machine is not accidentally operated during the work. When these preliminary operations are completed, the electrode tips 21,
22 can be exchanged.

[0007]

However, the above cooling device has the following problems. First, when replacing the electrode tips 21 and 22, the cooling water passage T
It is necessary to drain the cooling water from inside, but since the path from the water stop valve 26 to the check valve 27 via the cooling water passage is long, the drainage time is long. Also,
Since the check valve 27 is disposed near the transformer 23 located above the spot welding machine 20, the cooling water cannot be completely removed only by the air pressure of the factory air. Further, since air of a predetermined pressure is used for drainage, when the electrode tips 21 and 22 are removed, the cooling water scatters around due to the residual pressure, which deteriorates the working environment.

Furthermore, if the replacement of the electrode tips 21 and 22 is performed while forgetting to remove the power plug 29, there is a possibility that the welding machine may be erroneously operated during the operation.

The present invention has been devised in view of the above-mentioned conventional problems, and an object of the present invention is to provide a cooling device for a spot welding machine which is suitable for replacing an electrode portion. .

[0010]

According to a first aspect of the present invention, there is provided a spot welding machine in which a cooling water flow path is formed so as to pass through an electrode portion of the spot welding machine. An on-off valve for stopping water supply and a check valve for preventing backflow of drainage are interposed in the middle of the road, and both the on-off valve and the check valve are located near the spot welding machine. Is characterized in that it is arranged.

According to a second aspect of the present invention, in the first aspect, the on-off valve can be opened and closed in conjunction with an on / off operation of a power supply circuit of the spot welding machine. Things.

[0012]

According to the first aspect of the present invention, while the spot welding operation is being performed, the on-off valve is in the open state. To cool down. When replacing the electrode section, the on-off valve is closed and the supply of cooling water to the electrode section is stopped.
At this time, since both the on-off valve and the check valve are arranged near the spot welding machine, the amount of cooling water accumulated between them is small. Therefore, even when the electrode part is replaced, only a small amount of cooling water leaks from the electrode part. For this reason, there is no need to perform forced drainage using air, and therefore, there is no situation in which cooling water is scattered.

According to the second aspect of the present invention, when replacing the electrode section, the power supply circuit is turned off. Thereby, the on-off valve is closed, and the supply of the cooling water to the electrode unit is stopped. Therefore, power is not supplied during the replacement of the electrode portion, and a situation in which the spot welder is erroneously operated during this time is reliably avoided.

FIG. 1 is a block diagram showing an embodiment of the present invention.
A description will be given based on FIG. In FIG. 1, reference numeral 1 denotes a spot welding machine main body, and a pair of upper and lower electrode tips 2A, 2A.
B (corresponding to the electrode section of the present invention). In this embodiment, the lower electrode 2B is a fixed electrode, and the upper electrode 2B is a movable electrode (elevated and lowered by air pressure) which can be raised and lowered.

A flow path R for passing cooling water for cooling the electrode tips 2A and 2B is provided for the welding machine body 1. Of these, two cooling water passages 3A, 3B are formed inside the welding machine body 1 so as to pass through both electrode tips 2A, 2B. One cooling water passage 3A
Is an inlet 4 near the upper electrode tip 2A (movable electrode).
A is formed, and a drain port 5A is opened in the upper part of the welding machine main body 1. The other cooling water passage 3B has an inlet 4B opened at the center of the side surface of the welding machine main body 1, and a drain 5B opened above it.

On the other hand, a transformer 6 serving as a welding power source is disposed above the spot welding machine main body 1, and is connected to a water supply / drainage facility of a factory facility (not shown) to supply cooling water to the spot welding machine main body 1. The end portions of a water supply manifold 7 for supplying water and a drainage manifold 8 extend respectively. Water supply branch pipes 7A and 7B are connected between the water supply manifold 7 and the above-described inlets 4A and 4B, and both cooling water passages 3A and 3B of the spot welding machine.
Water can be supplied to In addition, a drainage branch pipe 8 is provided between the drainage manifold 8 and the drainage ports 5A and 5B.
A and 8B are connected, and the inside of both cooling water passages 3A and 3B can be drained.

In the water supply branch pipes 7A and 7B, on-off valves 9A and 9B for opening and closing the water supply branch pipes 7A and 7B to supply and stop the cooling water are provided near the inlets 4A and 4B, respectively. ing. Since the on-off valves 9A and 9B are well-known, their detailed internal structure is omitted, but both are connected to the air pipe 10, and when the air is supplied, the water supply branch pipes 7A and 7B are closed and the air is supplied. When the supply of water is not performed, the water supply branch pipes 7A and 7B are kept open. Furthermore, both water supply pipes 7
In the positions near both drain ports 5A and 5B in A and 7B,
Backflow prevention valves 11A and 11B for preventing the drainage from flowing back to the spot welding machine main body 1 are provided.

Further, an electromagnetic on-off valve 1 is located near the confluence of the air pipe 10 communicating with the on-off valves 9A, 9B.
2 are provided. On the other hand, the spot welding machine body 1 is connected to a power supply circuit 13 incorporated in the transformer 6, and in this embodiment, is connected to the welding machine body 1 via a magnet switch 14 and a welding power source 15 for the welding operation. (AC400V) and a control power supply 16 (AC100) connected to the electromagnetic on-off valve 12 for controlling its opening and closing.
V). Further, a disconnection opening / closing plug 17 is connected to the power supply circuit 13 to supply and stop electric power to and from the welding machine body 1 by opening and closing.
The electromagnetic on-off valve 12 can be opened by a relay (not shown) activated by opening the on-off plug 17.

Next, the operation and effect of this embodiment configured as described above will be specifically described. When performing the welding operation, the on-off plug 17 is connected, so that the electromagnetic on-off valve 12 is in a closed state, so that air is not supplied to both on-off valves 9A and 9B. The two on-off valves 9A, 9B are both open. Therefore, from the water supply manifold 7 to both water supply branch pipes 7
The cooling water diverted to A and 7B passes through the on-off valves 9A and 9B and is introduced into the cooling water passages 3A and 3B in the spot welding machine main body 1 through the introduction ports 4A and 4B. Then, while cooling the electrode tips 2A and 2B, the water is drained through the drainage pipes 8A and 8B and the drainage manifold 8 through the drainage ports 5A and 5B.

When the electrode tips 2A and 2B are to be replaced, the opening / closing plug 17 is first opened. Thereby, while the power supply from the welding power source 15 to the welding machine body 1 is stopped, the relay is activated in conjunction with the opening / closing operation of the opening / closing plug 17, so that the electromagnetic opening / closing valve 12 is switched to the open state. . As a result, air is supplied to the air pipe 10, so that the on-off valves 9A and 9B are closed, and the supply of cooling water to the welding machine body 1 is stopped. This allows
The cooling water is supplied to both open / close valves 9A and 9B and both check valves 11A and 1B.
1B.

At this time, as described above, both on-off valves 9
Since both A and 9B and the check valves 11A and 11B are arranged in the vicinity of the welding machine body 1, the length of the path for retaining the cooling water is short, and therefore the amount of the retained cooling water is small. Is also relatively small. Therefore, the replacement of the electrode tips 2A, 2B opens the cooling water passages 3A, 3B, from which the cooling water leaks. However, since the amount of the cooling water is small, the recovery is completed in a short time. Further, unlike the related art, since there is no need to perform forced drainage using air, there is no situation where cooling water is scattered around. Further, when replacing the electrode tips 2A and 2B, the opening / closing plug 1
Since the opening operation of the welding machine 7 is assumed, that is, the power supply to the welding machine body 1 is stopped, the welding machine is not accidentally operated during the replacement work, and safety is secured. The effect is also obtained.

The present invention can be variously modified.
The following modifications are also included in the technical scope of the present invention.

The on-off valves 9A and 9B are of the type that performs opening and closing operations by the air pressure of factory air, but may be electromagnetic on-off valves that are directly linked to the opening and closing of the on-off plug 17.

[Brief description of the drawings]

FIG. 1 is a front view showing a piping state of a spot welding machine.

FIG. 2 is a schematic diagram of FIG.

FIG. 3 is a front view showing a piping state of a conventional spot welding machine.

FIG. 4 is a schematic view of a conventional piping situation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Welding machine main body 2A, 2B ... Electrode tip 3A, 3B ... Cooling water passage 9A, 9B ... On-off valve 11A, 11B ... Check valve 13 ... Feeding circuit R ... Flow path

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshio Iwazuki 25, Kamifujiike, Yoshiwara-cho, Toyota-shi, Aichi Pref.

Claims (2)

[Claims] A cooling water flow path is formed in the spot welding machine so as to pass through an electrode portion thereof, and an opening / closing valve for stopping water supply and a reverse flow of drainage are provided in the middle of the flow path. A cooling device for a spot welder, wherein a check valve for preventing the flow is interposed, and both the on-off valve and the check valve are arranged near the spot welder. 2. The cooling device for a spot welding machine according to claim 1, wherein said on-off valve can be opened and closed in conjunction with an on / off operation of a power supply circuit of said spot welding machine.