JP2000084668A - Water cooled torch for arc welding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a power supplying cable and a cooling water hose being damaged even if the temperature of cooling water rises in a water cooled torch for arc welding. SOLUTION: A temperature switch 30 is arranged in a torch head part, with a measuring terminal 30a brought into contact with the temperature measuring part 3S of a torch body 3. Then, terminals 30b, 30c are connected serially to an operating switch 9. For example, if the quantity of cooling water decreases that flows in the power supplying cable 16, and if the temperature of its measuring part 3S exceeds a preset prescribed temperature, the terminals 30b, 30c spread apart in-between, stopping welding forcedly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-cooled torch for arc welding used when performing TIG welding or mag welding.

[0002]

2. Description of the Related Art FIG. 3 shows a configuration in which cooling water is supplied to a torch head by a cooling water hose, and a power cable for supplying power to the torch head is cooled by the cooling water that cools the torch head. FIG. 4 is an external connection diagram of a conventional water-cooled torch for TIG welding, and FIG. 4 is an enlarged sectional view of a portion A in FIG.

[0003] In these figures, reference numeral 1 denotes a water-cooled torch, which is a torch head 1a that is held and operated by an operator.
And a cable 1b for connecting the torch head 1a to the welding power source 2.

The torch head 1a includes a torch body 3 made of a copper alloy whose outer periphery is covered with an insulator, a cylindrical holder 4 screwed to the torch body 3, a cap 5, a nozzle 6, a torch body 3 and a nozzle 6 Packing 7, which is arranged between
An electrode 8 fixed to the torch body 3 by the cap 5,
It comprises an operation switch 9 and the like arranged on the outer periphery of the holder 4. A band 10 fixes the operation switch 9 to the holder 4.

[0005] The cable section 1b includes a cooling water hose 15, a power supply cable 16, a gas hose 17, an operation cable 18,
And a covering hose 19 covering these together.

The cooling water hose 15 is a hose made of synthetic resin, and has one end connected to the connection terminal 3a of the torch body 3 and the other end connected to the cooling water supply port 2a arranged on the front surface of the welding power source 2. Have been. The cooling water supply port 2a is connected to a cooling water supply source 20 such as a water tap via a valve 2b inside the welding power supply 2. 2c is a pressure switch.

The power supply cable 16 has a structure in which a power cable 16b is disposed inside a synthetic resin hose 16a, and cooling water flows around the power cable 16b. One end of the power cable 16b is connected to a connection terminal 3b of the torch body 3. The other end is connected to a copper alloy conducting metal fitting 21 arranged on the front surface of the welding power source 2. The current-carrying bracket 21 is connected to one output terminal 2 d of the welding power source 2. Reference numeral 22 denotes a discharge hose, the other end of which is connected to the drain groove 23.

The gas hose 17 has one end connected to the connection terminal 3c of the torch body 3 and the other end connected to a gas supply port 2e arranged on the front of the welding power source 2. The gas supply port 2e is connected to a gas cylinder 24, which is a shield gas supply source, via a valve 2f inside the welding power source 2.
2g is a pressure switch.

The operation cable 18 is a two-core cable, one of which is connected to the terminals 9a and 9b of the operation switch 9, and the other of which is connected to a control circuit (not shown) inside the welding power source 2 via the connector 25. Have been.

Reference numeral 26 denotes a welding cable, which connects the work 27 to the other output terminal 2h of the welding power source 2.

Next, the operation of the conventional water-cooled torch 1 having the above configuration will be described.

When the operation switch 9 is turned on, the valve 2b,
2 f is opened, and the cooling water and the shielding gas are supplied to the water-cooled torch 1. Further, a voltage is applied between the output terminal 2d and the output terminal 2h, and an arc can be generated between the electrode 8 and the work 27. The shielding gas supplied from the gas cylinder 24 shields the surroundings of the arc and the molten metal from the atmosphere. The cooling water supplied from the cooling water supply source 20 cools the torch body 3 and then cools the power cable 16.
b is cooled and discharged to the drain port 23. By flowing the cooling water through the above-described path, the cooling efficiency of the torch head 1a can be increased, and damage to the torch body 3 and the nozzle 6 due to arc heat can be reduced. In addition, the power cable 16 is cooled by water that has cooled the torch head 1a.
Since b is cooled, the cross-sectional area of the power cable 16b can be reduced, and the weight of the power supply cable 16 can be reduced. Thereby, the outer diameter of the coated hose 19 can be further reduced, and the flexibility of the coated hose 19 itself can be improved.

[0013]

As a material for the hoses constituting the cooling water hose 15 and the current-carrying cable 16, a vinyl-based material which is excellent in pressure resistance and flexibility and does not easily break is employed. If the radius is about 80 mm or more, the cooling water amount hardly decreases. However, the work place is not limited to a flat place, and the length of the cable portion 1b is 3 to 10 m. For this reason, the flow rate of the cooling water may be reduced due to extreme bending, erroneous mounting of a heavy object, or the like. As described above, since the cross-sectional area is selected on the assumption that the power cable 16b is water-cooled, when the amount of cooling water decreases, the temperature of the cooling water in the power supply cable 16 immediately rises, and the material of the hose is reduced. In the case of vinyl, it breaks when the temperature exceeds 80 ° C.
When the temperature of the cooling water in the power supply cable 16 exceeds 80 ° C., the temperature of the torch body 3 also increases, and the cooling water hose 15 connected to the torch body 3 is also damaged. In such a case, the entire energizing cable 16 or cooling water hose 15 had to be replaced with a new one, which not only reduced workability but also increased running costs.

The present invention has been made in view of the above-mentioned circumstances, and provides a water-cooled torch for arc welding in which a current-carrying cable and a cooling-water hose are not damaged even when the temperature of the cooling water rises. It is intended to do so.

[0015]

According to a first aspect of the present invention, a flexible cooling water hose and a current-carrying cable are connected to a torch head, respectively. Cooling the torch head with cooling water supplied via the cooling water, and cooling the power cable wired inside the energizing cable with the cooling water after cooling. A temperature sensor that detects a temperature near a connection between the unit and the power cable, and opens when the temperature near the connection detected by the temperature sensor exceeds a predetermined value, and when the temperature is below the predetermined value, An open / close switch that is in a closed state, an operation switch that turns on / off power supply to the torch head unit via the power cable,
And the open / close switch is connected in series to the operation switch.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 1 is a sectional view of a torch head of a water-cooled torch for arc welding according to the present invention, and corresponds to FIG. 4 in the above-mentioned conventional example. FIG. 2 is a connection diagram of the operation switches. And FIG.
Is used for TIG welding (for arc welding) in which cooling water is supplied to a torch head portion by a cooling water hose, and a power cable for supplying power to the torch head portion is cooled by the cooling water that has cooled the torch head portion. FIG. 3 is an external connection diagram of a (type) water-cooled torch. The present invention has a characteristic portion in FIG. 1, and therefore, FIG. 3 is common to that of the conventional example.

In these figures, reference numeral 1 denotes a water-cooled torch, which is a torch head 1a which is held and operated by an operator.
And a cable 1b for connecting the torch head 1a to the welding power source 2.

The torch head 1a includes a torch body 3 made of a copper alloy whose outer periphery is covered with an insulator, a cylindrical holder 4 screwed to the torch body 3, a cap 5, a nozzle 6, a torch body 3 and a nozzle 6 Packing 7, which is arranged between
An electrode 8 fixed to the torch body 3 by the cap 5,
It comprises an operation switch 9 and the like arranged on the outer periphery of the holder 4. A band 10 fixes the operation switch 9 to the holder 4. In addition, about the operation switch 9,
Details will be described later.

The cable section 1b includes a cooling water hose 15, a power supply cable 16, a gas hose 17, an operation cable 18,
And a covering hose 19 covering these together.

The cooling water hose 15 is a synthetic resin hose having one end connected to the connection terminal 3a of the torch body 3 and the other end connected to the cooling water supply port 2a arranged on the front of the welding power source 2. Have been. The cooling water supply port 2a is connected to a cooling water supply source 20 such as a water tap via a valve 2b inside the welding power supply 2. 2c is a pressure switch.

The power supply cable 16 has a structure in which a power cable 16b is disposed inside a synthetic resin hose 16a, and cooling water flows around the power cable 16b. One end of the power cable 16b is connected to a connection terminal 3b of the torch body 3. The other end is connected to a copper alloy conducting metal fitting 21 arranged on the front surface of the welding power source 2. The current-carrying bracket 21 is connected to one output terminal 2 d of the welding power source 2. Reference numeral 22 denotes a discharge hose, the other end of which is connected to the drain groove 23.

The gas hose 17 has one end connected to the connection terminal 3c of the torch body 3 and the other end connected to a gas supply port 2e arranged on the front of the welding power source 2. The gas supply port 2e is connected to a gas cylinder 24, which is a shield gas supply source, via a valve 2f inside the welding power source 2.
2g is a pressure switch.

The operation cable 18 is a two-core cable, one of which is connected to the terminals 9 a and 9 b of the operation switch 9, and the other of which is connected to a control circuit (not shown) inside the welding power source 2 via the connector 25. Have been.

A welding cable 26 connects the work 27 to the other output terminal 2h of the welding power source 2.

Next, the features of the present invention will be described.

A reference numeral 3S shown in FIG. 1 is a temperature measuring section provided at the end of the torch body 3. Reference numeral 30 denotes a temperature switch (open / close switch), and a temperature measurement terminal 30 for measuring a temperature.
a and terminals 30b and 30c. Terminal 30
When the temperature T measured at the temperature measuring terminal 30a is 70 ° C. or lower, the circuit is closed between b and 30c, and opens when the temperature T exceeds 70 ° C. The temperature measuring terminal 30a is fixed to the torch body 3 so as to be in close contact with the temperature measuring section 3S, and the terminals 30b and 30c are the terminals 9a and 9b of the operation switch 9, respectively.
9b in series.

Next, the operation of the water-cooled torch for arc welding configured as described above will be described.

For example, it is assumed that the cooling water hose 15 or the power supply cable 16 is crushed and the flow of the cooling water is deteriorated. The temperature of the cooling water in the power supply cable 16 gradually increases, and accordingly, the temperature of the temperature measuring unit 3S also gradually increases. When the temperature of the temperature measuring section 3S exceeds 70 ° C., the terminal 3
Open between 0b and 30c. As a result, even if the operation switch 9 is turned on, the output between the output terminals 2d and 2h of the welding power source 2 becomes 0, and the welding is forcibly stopped. When the supply of power is stopped, the temperatures of the power cable 16b and the torch body 3 stop rising and are suppressed to 80 ° C. or less. Therefore, the power supply cable 16 and the cooling water hose 15 are not damaged.

When the flow rate of the cooling water is sufficient, the temperature measuring unit 3
Since the temperature of S is kept low, the space between the terminals 30b and 30c is closed, and the welding operation can be performed by turning on and off the operation switch 9.

In the above description, the temperature measuring terminal 30
Although the temperature switch having the terminal a and the terminals 30b and 30c is used, the temperature sensor and the switch may be separately provided.

Further, the temperature T at which the terminal 30b and the terminal 30c are opened is set.
Is set to 70 ° C. in the above description, but the temperature T is not limited to this, and an appropriate value may be selected depending on the material of the hose used for the power supply cable 16 and the cooling water hose 15 and the like.

Further, in the above description, the case where the present invention is applied to a water-cooled torch for TIG welding is described. However, the present invention is not limited to this, and is also applied to, for example, a water-cooled torch for MAG welding. be able to.

[0034]

As described above, according to the present invention,
A temperature sensor that detects the temperature near the connection between the torch head and the power cable, and opens when the temperature near the connection detected by the temperature sensor exceeds a predetermined value and closes when the temperature is below a predetermined value. And an operation switch for turning on / off the power supply to the torch head unit via a power cable.The open / close switch is connected in series with the operation switch. By turning off the power supply to the torch head regardless of whether the switch is on or off, the arc welding is forcibly stopped when the temperature near the connection exceeds a predetermined value. The hoses do not heat up anymore, so that they can be effectively prevented from being damaged by heat.

[Brief description of the drawings]

FIG. 1 is a sectional view of a torch head of a water-cooled torch for TIG welding (for arc welding) according to the present invention.

FIG. 2 is a connection diagram of an operation switch according to the present invention.

FIG. 3 is an external connection diagram of the present invention and a conventional water-cooled torch for TIG welding.

FIG. 4 is a cross-sectional view of a torch head of a conventional water-cooled torch for TIG welding.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water-cooled torch 1a Torch head part 1b Cable part 3S Temperature measurement part 9 Operation switch 15 Cooling water hose 16 Power supply cable 16b Power cable 30 Temperature switch 30a Temperature sensor (measurement terminal) 30b, 30c open / close switch (terminal)

Claims (1)

[Claims] 1. A flexible cooling water hose and a current-carrying cable are connected to a torch head, respectively, and the torch head is cooled by cooling water supplied through the cooling hose. In a cooling torch for arc welding formed by cooling a power cable wired inside the current-carrying cable by cooling water, a temperature sensor for detecting a temperature near a connection portion between the torch head and the power cable, An open / close switch that is opened when the temperature near the connection portion detected by the temperature sensor exceeds a predetermined value and is closed when the temperature is equal to or less than the predetermined value, via the power cable to the torch head unit; An operation switch for turning on / off the supply of power, and the on / off switch is connected in series to the operation switch. Water-cooled torch for that arc welding.