JPH07204857A - Method and device for preventing spatter deposition in welding torch - Google Patents

Abstract

PURPOSE:To prevent the spatter deposition and to improve the efficiency of the welding work by injecting the spatter adhesion preventing liquid into the welding torch together with highly compressed air for the prescribed period of time while the inert gas shielded arc welding is stopped. CONSTITUTION:The inside of a welding torch 14 used in the inert gas shielded arc welding is connected to a high pressure air source 24 through a conductor 25. A sprayer 26 to spray the spatter adhesion preventing liquid 28 into the conductor 25 following the flow of the air in the conductor 25, and a solenoid valve 27 of the constantly closed type are interposed to the conductor 25. A solenoid 27a of the solenoid valve 27 is connected to the power source through a sensor 12 to detect the welding stopped condition and a timer so that the solenoid valve 27 may be opened for the prescribed period of time while the welding is stopped. This constitution allows the highly compressed air from the high pressure air source 24 to flow in the conductor 25, and the spatter adhesion preventing liquid 28 is sprayed in the sprayer 26, and injected into the welding torch 14 together with the highly compressed air.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for preventing spatter deposition in a welding torch used for inert gas arc welding.

[0002]

2. Description of the Related Art Inert gas arc welding is one in which a meltable material is heated and melted by an arc generated between an electrode in a welding torch and a work while ejecting an inert (inert) gas from the welding torch. Thus, the arc and the welded portion are protected from contact with the outside air by the inert gas, and deterioration due to oxidation or the like can be prevented.

[0003]

By the way, during welding by the above welding torch, spatter is unavoidable to be scattered around, and as the welding is repeated for a long time, the spatter invades and accumulates in the welding torch. To go. Such deposited spatter clogs the nozzle of the welding torch and prevents the normal ejection of inert gas, thus hindering the formation of a good quality weld.

Therefore, conventionally, the welding torch is sometimes disassembled to mechanically remove the attached spatter, but such disassembling and cleaning work is not only troublesome, but also the welding work is interrupted. This leads to a reduction in work efficiency.

The present invention has been made in view of such circumstances, and provides an effective method and apparatus for preventing spatter deposition in the welding torch without disassembling and cleaning the welding torch. The purpose is to

[0006]

To achieve the above object, the first aspect of the present invention is to inject a spatter adhesion preventing liquid together with high-pressure air into a welding torch for a predetermined time during a pause of inert gas arc welding. It is a feature of.

Further, according to the present invention, the inside of a welding torch used for inert gas arc welding is connected to a high-pressure air source via a conduit, and the conduit is connected with a spatter adhesion preventing liquid on the tube with the flow of air in the tube. And a normally closed solenoid valve, and the solenoid of the solenoid valve is connected to a power source via a sensor and a timer for detecting a welding pause state, and the solenoid valve is kept in the welding pause state. The second feature is that the opening is performed for a predetermined time.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

First, in FIG. 1, the present invention is applied to welding a disk-shaped second work W ₂ to one end surface of a cylinder-shaped first work W ₁ .

In order to support the first work W ₁ , a cylindrical jig 1 which is removably fitted to the inner peripheral surface of the first work W ₁ is prepared, which comprises an electric motor 3 having a stator fixed to a base 2.
Is connected to the output shaft 3a. On the outer circumference of the jig 2, a positioning flange 1a that abuts the outer end surface of the first work W ₁
Is formed.

In order to support the second work W ₂ ,
A stepped cylindrical work holding member 5 is provided which fits in the center hole 4 in a removable manner and abuts on the outer end surface thereof. The work holding member 5 has a thrust on the front surface of a support plate 7 fixed to a piston rod 6a of an air cylinder 6. It is rotatably connected via a ball bearing 8. A plurality of guide rods 9 are provided on the rear surface of the support plate 7 in parallel with the piston rod 6a, and these are slidable in a guide hole 11 formed in a front end flange 10 of a cylinder body 6b of the air cylinder 6. Is inserted into. Limit switch 12 on front end flange 10
A (welding pause sensor) is attached, and a dog 13 that operates the sensor is attached to the support plate 7. The cylinder body 6b of the air cylinder 6 is fixed to the base 2 coaxially with the electric motor 3.

If the first and second works W ₁ and W ₂ are inserted into the jig 1 and the work holding member 5, respectively, and the air cylinder 6 is operated to advance the piston rod 6a, The second work W ₂ can be coaxially pressed and held at the inner end of the first work W ₁ .

As shown in FIGS. 1 and 2, a welding torch 14 used for welding the _two works W ₁ and W ₂ has a tubular torch body 15 and a torch nozzle 16 screwed to the front end of the torch body 15. And an electric conduit 17 disposed in the hollow portion of the torch body 15, the electric conduit 17 having the tip of the filler wire 19 fed from the wire feeding device 18 projected outside the torch nozzle 16. Support in the state. At the rear end of the torch body 15, the inert gas cylinder 2
A gas pipe 21 connected to 0 is connected, and a normally closed electromagnetic valve 22 is interposed in the gas pipe 21.

The torch body 15 is supported by being connected to a piston rod 31a of an air cylinder 31 supported by the base 2, and the reciprocating operation of the air cylinder 31 causes both workpieces W to move.
_The welding work position of ₁ and W ₂ facing the welded portion 32 and the welding rest position of withdrawing from the welded portion 32 are shifted.

A connecting pipe 23 is provided on one side of the torch body 15 and has an opening inside thereof.
4 is connected to the conduit 25. A sprayer 26 and a normally-closed solenoid valve 27 are provided in series in the conduit 25. The sprayer 26 stores a known spatter adhesion preventing liquid 28 in its reserve tank 26a, and
When air flows into the pipe 5, the spatter adhesion preventing liquid 28 is sprayed into the conduit 25.

FIG. 3 shows the operating electrical circuit of the solenoid valve 27 in the conduit 25. The solenoid 27a of the solenoid valve 27 is a timer 2
The relay coil 29c of the timer 29 is connected to the power source 30 via the limit switch 12 through the normally open relay contact 29s of FIG. The limit switch 12 closes only when the actuator 12a thereof swings to the left in FIG. 1. Therefore, when the piston rod 6a moves forward toward the work holding position, the dog 13 is moved forward. It does not operate even if it touches the actuator 12a, but when the piston rod 6a returns, the dog 13
As a result, the actuator 12a is swung to the left to cause a closing operation. In addition, the normally open relay contact 2 of the timer 29
In 9s, a predetermined time delay occurs when returning.

Next, the operation of this embodiment will be described.

First, the piston rod 6a of the air cylinder 6
In the retracted state, the first and second works W ₁ and W ₂ are mounted on the jig 1 and the work holding member 5. Then, when a start button (not shown) is pressed, the air cylinder 6 operates, and the work holding member 5 is moved through the piston rod 6a and the support plate 7.
Is moved forward and both works W ₁ and W ₂ are held in the contact state as shown in FIG. Next, the electric motor 3 is operated, and the two workpieces W ₁ and W ₂ are rotationally driven by the output shaft 3a at a constant low speed. At this time, since the work holding member 5 is supported by the support plate 7 via the thrust ball bearing 8, the work holding member 5 rotates together with the second work W ₂ without any trouble and continues to press the second work W ₂ against the first work W _1. be able to.

Subsequently, the welding torch 14 is shifted from the rest position to the welding position by the operation of the air cylinder 31, and welding is started. That is, a high voltage is applied between the electric conduit 17 and the welded portions 32 of the works W ₁ and W ₂ , and the solenoid valve 22 is opened to supply the inert gas from the inert gas cylinder 20 into the torch body 15. . Then, the tip portion of the filler wire 19 is melted by the arc generated between the filler wire 19 and the welded portion 32, and the droplets are welded.
And is welded.

During this time, the inert gas supplied to the torch body 15 is ejected from the torch nozzle 16 and wraps the droplets and the welded portion 32, so that they are shielded from the outside air and escaped from oxidation. On the other hand, when the filler wire 19 is consumed, the wire feeding device 18 is activated to feed the filler wire 19, and the consumed amount is replenished.

When the two workpieces W ₁ and W ₂ make one revolution and the welding of them is completed, the electric motor 3 stops rotating and the air cylinder 31 moves back to retract the welding torch 14 to the rest position. . Then, the air cylinder 6 moves back to retract the work holding member 5 and release the second work W ₂ , so that both welded works W ₁ and W ₂ can be taken out from the jig 1.

By the way, since the dog 13 of the support plate 7 actuates the limit switch 12 to urge the relay coil 29c of the timer 29 during the backward movement of the work holding member 5,
The relay contact 29s is closed for a certain period of time to energize the solenoid 27a of the solenoid valve 27. Therefore, the solenoid valve 27 is opened for a certain period of time, the high pressure air from the high pressure air source 24 flows into the conduit 25, and the sprayer 26 is sprayed with the spatter adhesion preventing liquid 28 in accordance with this, and the welding torch 14 with the high pressure air. Is injected inside. Then, while the spatter adhesion preventing liquid 28 is being sprayed on each part inside the welding torch 14, the high-pressure air blows out the spatter scattered inside the welding torch 14 during welding to the outside of the torch nozzle 16. After that, the same operation is repeated every time welding is performed.

As described above, the welding torch 1 is operated while the welding is stopped.
4. Since the spatter adhesion preventing liquid is sprayed to each part in 4 and the invasion spatter is blown out, the invasion spatter is prevented from adhering to the inside of the welding torch 14 at the time of welding, and the invasion spatter is surely made to the outside at the time of rest. Therefore, it is possible to effectively prevent the deposition of spatters and enable the stable supply of the inert gas to the welded portion 32. Further, since it is not necessary to disassemble and clean the welding torch, the efficiency of welding work is improved.

In the above embodiment, various design changes can be made without departing from the gist of the present invention. For example,
The limit switch 12 may be configured to be closed when the piston rod 6a is moved forward.
It is also possible to perform the closing operation at the time of forward or backward movement of 6. A proximity switch may be used instead of the limit switch 12. Furthermore, the present invention can be applied to a torch for inert gas tungsten arc welding using a tungsten electrode.

[0025]

As described above, according to the first feature of the present invention, since the spatter adhesion preventing liquid is injected into the welding torch together with the high pressure air for a predetermined time during the pause of the inert gas arc welding, the work piece is detached. Spraying of the spatter adhesion prevention liquid inside the welding torch by using the welding pause time
It is possible to effectively prevent the deposition of spatter in the welding torch by simultaneously performing the blowing out of the invading spatter, which can contribute to the stable supply of the inert gas and the improvement of the welding work efficiency.

According to the second aspect of the present invention, the inside of the welding torch used for the inert gas arc welding is connected to a high pressure air source through a conduit, and the conduit is connected with the flow of air in the pipe. A sprayer for spraying the anti-spatter adhesion liquid on the pipe, and a normally-closed solenoid valve are interposed, and the solenoid of the solenoid valve is connected to a power source via a sensor and a timer for detecting a welding halt state, Since the solenoid valve is opened for a predetermined time while the welding is stopped, it is possible to automatically spray the spatter adhesion preventing liquid into the welding torch and blow out the invading spatter, further improving the welding work efficiency. Can bring

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention and is an overall side view of a welding apparatus.

FIG. 2 is a longitudinal sectional view of a main part of the welding torch in FIG.

FIG. 3 is an operation electric circuit diagram of a solenoid valve that opens and closes a conduit connecting the welding torch and a high-pressure air source.

[Explanation of symbols]

 12 Limit Switch (Sensor) 14 Welding Torch 24 High Pressure Air Source 25 Conduit 26 Sprayer 27 Solenoid Valve 28 Spatter Adhesion Prevention Liquid 29 Timer 30 Power Supply

Claims (2)

[Claims] 1. A spatter adhesion preventing liquid (2) is placed in a welding torch (14) for a predetermined time during a pause of inert gas arc welding.
A method for preventing spatter deposition in a welding torch, characterized in that 8) is injected together with high pressure air. 2. The inside of a welding torch (14) used for inert gas arc welding is connected to a high-pressure air source (24) through a conduit (25), and the conduit (25) includes the pipe (2).
A sprayer (26) for spraying the spatter adhesion preventing liquid (28) onto the pipe (25) in accordance with the flow of air in 5) and a normally closed solenoid valve (27) are provided. The solenoid (27a) of 27) is connected to the power source (30) through the sensor (12) for detecting the welding rest state and the timer (29), and the solenoid valve (27) is opened for a predetermined time during the welding rest. An apparatus for preventing spatter deposition in a welding torch, characterized in that