JPH0530865Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a lubricating device for a power feeding portion of a power feeding device for a resistance welding machine having a power feeding cylinder.

[Prior Art] Conventionally, in a power supply device for a resistance welding machine having this type of power supply cylinder, the power supply terminal and the power supply ring, and the shaft and the power supply ring are repeatedly brought into contact and separated in response to welding work, thereby welding from the transformer. Power to the gun was intermittent. Among these devices, there is one in which silver grease is placed on the power supply ring portion (see, for example, Japanese Patent Laid-Open No. 75886/1986).

[Problem to be solved by the invention] By the way, in general, when viewed from a microscopic perspective, each contact surface is formed with an uneven surface.
When power is supplied, the convex portions of each surface contact each other to conduct electricity, so a high temperature region is generated locally on the contact surfaces. Therefore, even if the silver grease is placed there, the grease cannot self-melt even at a locally high temperature, so the oil does not flow sufficiently to the current-carrying part, causing oil to run out on the contact surface. There is a risk that the contact surface may become rough.

This invention was devised in view of the above-mentioned problems of the conventional technology, and its purpose is to constantly interpose animal fat or fat made of beef tallow or pork fat in the contact/separation part. Therefore, it is an object of the present invention to provide a lubricating device for a power supply device for a resistance welding machine, which can avoid abnormal temperature rises in contact and separation parts and provide sufficient lubrication.

[Means for Solving the Problems] In order to achieve the above object, the power supply device for a resistance welding machine in this invention has a shaft penetrating a power supply cylinder having a power supply terminal, and a shaft that slides between the shaft and the inner wall of the power supply cylinder. A piston is provided, and a power supply ring is provided between the piston and the power supply terminal and surrounds the shaft, wherein at least the contact surfaces of the power supply terminal, the power supply ring, and the power supply ring are coated with beef tallow or pork fat. It is characterized by the presence of animal fats and oils.

[Operation] When the shaft slides forward in the power supply cylinder (first embodiment) or rotates (second embodiment) and the electrode at the tip of the movable arm clamps the workpiece, pressurized fluid is pumped into the power supply cylinder. The piston presses the power supply ring against the power supply terminal and shaft. Therefore, current from the transformer is sent to the electrodes via the power supply terminal, power supply ring, and shaft to perform the welding operation.

When the welding work is completed, the pressure fluid in the power supply cylinder is removed and the piston is separated from the power supply ring, so that the current supply between the power supply terminal and the shaft is terminated.

In this way, the power supply ring repeatedly comes into contact with and separates from the power supply terminal and the shaft depending on the welding work.

Therefore, since the power supply ring must move smoothly, it is advisable to provide a lubricating device.

At that time, the power supply ring becomes quite hot due to the intermittent current flow.

Therefore, if animal fat or fat made of beef tallow or pork fat is interposed at least on each contact surface between the power supply terminal and the power supply ring, and between the power supply ring and the shaft, the fat and oil will self-melt at high temperature and at that time, the molten heat will be taken away from the surroundings. This prevents an abnormal rise in the ambient temperature, that is, the temperature of the contact surfaces between the power supply terminal and the power supply ring, and between the power supply ring and the shaft. The contact and separation are carried out smoothly.

[Embodiment] In FIG. 1 which shows the first embodiment, 6 is a pressure cylinder, and the cylinder has a rod 3 which is a shaft.
A piston 7 for rod sliding with one end fixed is provided, and the inside of the cylinder is divided into a pressing chamber 8 and a return chamber 9 by the piston 7. Further, the cylinder case of the pressing cylinder 6 is formed with a pressing fluid supply port 10 communicating with the pressing chamber 8 and a retreating fluid supply port 11 communicating with the return chamber 9. A movable electrode 12 is attached to the other end of the rod 3. Reference numeral 1 denotes a power supply cylinder, which is formed separately and independently at a position adjacent to the pressure cylinder 6, and the rod 3 passes through the inside thereof. A ring-shaped power supply terminal 2 is disposed in the power supply cylinder 1 so as to surround the rod 3, a part of which protrudes outward from the power supply cylinder 1, and a cable connection part 13 is attached to the protrusion. It is equipped with This power supply terminal 2 is connected to the power supply cylinder 1.
The casing and the rod 3 are electrically insulated by an insulator 14. A piston 4 that slides under fluid pressure is disposed within the power supply cylinder 1, and a divided power supply ring 5 is installed between the piston 4 and the power supply terminal 2 so as to surround the rod 3. ing. The divided power supply ring 5 is made up of conductive pieces and insulating pieces arranged at intervals around the outer circumference of the rod 3. The surface of the piston 4 that contacts the divided power supply ring 5 forms an inclined surface, and the inclination is in a direction in which the wall thickness of the piston becomes thinner from the outside to the inside. Further, the surface of the divided power supply ring 5 that contacts the piston 4 is also inclined, and the inclination is in a direction in which the wall thickness of the divided power supply ring becomes thicker from the outside toward the inside. Therefore, the piston 4 and the split power supply ring 5 are configured to contact each other at the inclined surface. The cylinder case of the power supply cylinder 1 includes a piston pressing fluid supply port 15 that communicates with the inside of the cylinder, and a fat cup 1 that supplies animal fat and oil.
6 are provided respectively. Further, a fixed electrode 18 is attached to the other end of a fixed arm 17 whose one end is fixed to the cylinder case of the pressing cylinder 6, and power is supplied through the arm. In addition,
19 is a workpiece, and 20 is a cover.

As shown in the figure, the welded part of the metal workpiece 19 is positioned and set on its axis between the electrodes 12 and 18, and, for example, compressed air is sent from the pressing fluid supply port 10 of the pressing cylinder 6 to the pressing chamber 8, and the workpiece is retreated. When the compressed air in the return chamber 9 is discharged through the fluid supply port 11, the compressed air in the pressure chamber 8 is discharged to the piston 7.
is pressed, the rod 3 moves forward, and the movable electrode 12 at its tip cooperates with the fixed electrode 18 to clamp and support the workpiece 19. When compressed air is sent into the cylinder 1 from the pressing fluid supply port 15 of the power supply cylinder 1 at a time lag with the supply of compressed air to the pressure cylinder 6, the piston 4 is pressed by the compressed air, and the inside of the power supply cylinder 1 is pushed. Due to the slight sliding, the inclined surface of the piston 4 presses the split power supply ring 5 against the power supply terminal 2, and also reduces the distance between the alternating conductive pieces and insulating pieces of the split power supply ring 5, so that the entire ring is closed. The split power supply ring 5 is also pressed into contact with the rod 3 by reducing its diameter. As a result, power is supplied from the power supply terminal 2 to the movable electrode 12 via the divided power supply ring 5 and the rod 3, so that the desired welding work can be performed.

When the welding work is completed, the compressed air is removed from the pressing fluid supply port 15, and the piston 4 slides slightly and returns to its original position.
As the pressure on the divided power supply ring 5 is released, the divided power supply ring 5 separates from the power supply terminal 2, and the interval between the alternating conductive pieces and insulating pieces widens, causing the ring to expand in diameter and separate from the rod 3. Therefore, the circuit from the power supply terminal 2 to the rod 3 via the divided power supply ring 5 is broken.

When compressed air is sent to the retracting fluid supply port 11 of the press cylinder 6 at a time lag after the release of the compressed air from the press fluid supply port 15, this air enters the return chamber 9, presses the piston 7, and presses the rod 3. to retreat. At this time, the compressed air in the pressing chamber 8 is exhausted from the pressing fluid supply port 10.

Due to the retreat of the rod 3, the movable electrode 12 moves to the workpiece 1.
Since the workpiece 19 is separated from the welding apparatus 9, the workpiece 19 can be easily taken out of the welding apparatus.

As described above, the divided power supply ring 5 repeatedly connects and separates from the power supply terminal 2 and the rod 3 as the welding work is interrupted. Therefore, when the current is turned off and on, the split power supply ring 5 in particular tends to become hot, and its movement may not be carried out smoothly. To prevent this, the power supply cylinder 1 is equipped with a fat cup 16 that supplies animal fat made of beef tallow or pork fat.

The animal fat or fat made of beef tallow or pork fat stored in the fat cup 16 or the animal fat made of beef tallow or pork fat supplied to the fat cup 16 is always supplied to the periphery of the split power supply ring 5, and at least the power is supplied. Terminal 2, power supply ring 5, and power supply ring 5
Animal fat or fat consisting of beef tallow or pork fat is always present on each contact surface between the rod 3 and the rod 3.

This animal fat or fat made of beef tallow or pork fat self-melts in a high-temperature atmosphere, and at that time it takes away the melting heat from the surroundings. An abnormal rise in the temperature of each contact surface is avoided, each of these contact surfaces is sufficiently lubricated, and the power supply ring 5 is smoothly brought into contact with and separated from the power supply terminal 2 and the rod 3.

The second embodiment, shown in FIG. 2, is applied to a type of gun, such as an X-type gun, in which the rotating shaft 3 rotates when the arm 17 rotates, and the arm holds a workpiece. It is something.

Since the power supply terminal 2 and the power supply cylinder 1 are integrally constructed, and the arm 17 is fixed to the shaft 3, it is constructed of substantially the same members as the first embodiment. The same reference numerals will be given to the members, and explanations regarding their operations will be omitted.

In addition, for the supply of animal fat made of beef tallow or pork fat, a fat cup 16 is shown, but the means for this is, for example, by using a pipe communicating with a power supply cylinder, and injecting animal fat made of beef tallow or pork fat into the pipe. Natural oils and fats may be allowed to fall naturally or may be force-fed periodically.

[Effects of the invention] This invention is designed so that animal fat or fat made of beef tallow or pork fat is always present in the power supply ring, which repeatedly comes into contact with and separates from the power supply terminal and shaft in response to welding work. Even at high temperatures, animal fats and oils made of beef tallow or pork fat self-melt and take away their molten heat from the surroundings, resulting in an abnormality in the surrounding temperature, that is, the temperature of the contact surfaces between the power supply terminal and the power supply ring, and between the power supply ring and the shaft. Lifting is avoided, each of these contact surfaces is sufficiently lubricated, and the power supply ring, power supply terminal, and shaft are smoothly brought into contact with and separated from each other, and excellent current conduction is achieved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of one embodiment of a resistance welding machine equipped with a lubricating device according to this invention, and FIG. 2 is a cross-sectional view of a main part of another embodiment. 1...Power supply cylinder, 2...Power supply terminal, 3...
Shaft, 4... Piston, 5... Power supply ring.

Claims (1)

[Scope of utility model registration request] A shaft is passed through a power supply cylinder having a power supply terminal, a piston is provided that slides between the shaft and the inner wall of the power supply cylinder, and a power supply ring is provided between the piston and the power supply terminal and surrounds the shaft. A power supply for a resistance welding machine, characterized in that an oil supply means is provided for constantly interposing animal fat or fat made of beef tallow or pork fat on each contact surface between the power supply terminal and the power supply ring, and between the power supply ring and the shaft at least. Equipment lubrication system.