JP2897063B2 - TIG arc welding torch and welding equipment - Google Patents

Description

The present invention relates to a TIG arc welding torch and a welding apparatus,
Particularly, the present invention relates to a welding torch and a welding device suitable for performing TIG arc welding or hot wire TIG arc welding with good operability.

[Conventional technology]

TIG arc welding or hot wire TIG arc welding is a welding method in which an arc is generated between a non-consumable tungsten electrode and a workpiece while an inert gas is supplied, and an additional wire is supplied. This welding method is a widely used welding method because the arc stability is very good, and an inert gas is used as a shielding gas, so that high-quality welding without spatter can be performed.

As shown in FIG. 9, a conventional TIG arc welding torch includes an arc torch composed of a torch body 20, a cap 21, a nozzle 1a, a tungsten electrode 2a, and the like, an additional wire torch 24 separated from the arc torch, and a welding portion. The upper and lower sliders 22, the right and left sliders 23 for adjusting the insertion position of the addition wire 4a into the addition wire 4a; When performing manual welding, the additional wire torch is separated, and welding is performed with an arc torch in one hand and a wire torch in the other hand.

Further, in order to perform TIG arc welding with high efficiency, the torch is also used in hot wire TIG arc welding in which the additive wire 4a between the additive wire torch 24 and the workpiece 8a is electrically heated.

Next, details of the arc torch will be described with reference to FIG. The tungsten electrode 2a is sandwiched by a collet 30 having a slit formed at the tip, housed in a collet holder 31 having a tapered inner bottom, fixed in a state where the upper cap 21 is squeezed and protrudes from the nozzle 1a. You.

An inert gas (eg, argon gas) flows from the nozzle tip through the inside of the collet holder 31 and the inside of the nozzle 1a from the argon gas inlet 28 to make the tip of the tungsten electrode 2a an inert atmosphere. Electric power is supplied to the power supply unit 32, the collet holder 31, and the tungsten electrode 2a from the outside, and a voltage is applied between the tungsten electrode 2a and the workpiece to generate an arc. Since the temperature of the tungsten electrode 2a becomes high during the generation of the arc, the power supply unit 32 is cooled with water through the cooling water inlet 26 and the cooling water outlet 27.

[Problems to be solved by the invention]

The conventional welding torch described above has the following problems.

(A) In normal TIG arc welding, the welding wire 8a and the additional wire 4a are melted by arc heat, so that the additional wire 4a is formed at an angle of 10 to 45 ° with respect to the workpiece 8a from the front in the welding progress direction. Into the weld. In hot wire TIG arc welding in which the additive wire 4a is electrically heated, the additive wire 4a is inserted from a wide rear of the molten pool in order to stabilize the wire current. Also in this case, in order to insert the addition wire 4a from outside the nozzle of the arc torch, the addition wire is inserted at an angle of 10 to 60 ° with respect to the workpiece.

For this reason, in the conventional TIG arc welding, it is necessary to insert the additional wire 4a from either the front or the rear in the welding progress direction, and there is a problem in the directionality of the torch.

(B) Since the wire torch 24 is provided on the side surface of the arc torch, the narrow overflow portion cannot be constructed.

(C) Since the addition wire 4a is obliquely inserted into the tungsten electrode 2a arranged in the vertical direction, the wire insertion position changes greatly when the arc length changes, so that precise control of the arc length is required.

An object of the present invention is to provide a TIG arc welding torch capable of selecting a welding direction irrespective of an insertion direction of an additive wire, performing a narrow overflow portion, and having a margin of an arc length, and a welding apparatus having the welding torch. Is to do.

[Means for solving the problem]

The above-described object is to provide a power supply tip inside the nozzle tip, and make a tungsten electrode protrude from this power supply tip,
In addition, an addition wire insulation guide communicating with the addition wire guide disposed inside the nozzle is installed on the power supply tip, and the addition wire fed from the addition wire insulation guide is angled in a state substantially parallel to the tungsten electrode with respect to the tungsten electrode. It is achieved by setting to have.

Preferably, a water-cooling conduit having conductivity is provided inside the nozzle to cool and supply electricity to the power supply tip. Further, the power supply tip is disposed such that the tip end side is exposed to the shield gas flow path.

Next, the welding apparatus of the present invention comprises a TIG arc welding torch, a mechanism for rotating and driving the torch around its tungsten electrode, a heating and melting of the addition wire independently of the arc heat while energizing and heating the addition wire. And a control mechanism for causing the

[Action]

Since a tungsten electrode and an additional wire insulation guide for feeding the additional wire are provided on the power supply tip provided at the tip of the nozzle, the additional wire is inserted substantially parallel to the tungsten electrode and directly below the arch from near the tungsten electrode.

The influence of the insertion direction of the addition wire is reduced, and omnidirectional welding is performed, which allows welding to proceed regardless of the insertion direction of the addition wire.

The addition wire guide is provided inside the nozzle, the wire torch and the arc torch are integrated, and the entire torch has a compact structure, so that welding can be easily performed even on a narrow overflow portion.

When a trouble occurs in the welding operation when the tungsten electrode and the additional wire are close to each other, a welding power source is controlled by the control device to switch between the arc current and the wire current, so that welding can be performed without the trouble.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a front sectional view showing one embodiment of a TIG arc welding torch of the present invention, and FIG. 2 is a side view of FIG.

This TIG arc welding torch is a hollow torch
The tungsten electrode 2 and the additional wire insulation guide 6 are installed on a power supply tip 3 attached to the tip of the device by a replaceable mechanism.

The exchange mechanism includes, for example, the tungsten electrode 2 and the additional wire insulation guide 6 from the tip end side of the power supply tip 3.
May be a plug-in type, and may be a mechanism for fixing with a screw or a spring.

Further, a nozzle 1 made of ceramics or the like is fitted on the outer periphery of the tip of the torch body 14, and an insulating cover 13 is fitted on the torch body 14. Further, inside the torch body 14, a flow path 14a for flowing argon as an inert gas is formed, and blows out to the inner peripheral portion of the tip of the nozzle 1.

Inside the hollow torch body 14, a water-cooled conduit 9 having conductivity such as copper is provided, and the tip of the water-cooled conduit 9 is connected to a groove 3a formed in the power supply chip 3.
Therefore, the water cooling conduit 9 is connected to the power supply chip 3 by the cooling water.
Is cooled, and at the same time, since it has conductivity, current is supplied to the power supply tip 3 and the tungsten electrode 2 so that an arc can be generated between the tungsten electrode 2 and the workpiece 8.

As shown in FIGS. 4 and 5, the water-cooling conduit 9 is a water-cooling conduit 9a having a double pipe structure, and a water-cooling conduit having a partition plate therein and having two flow paths formed along the pipe axis direction. 9b etc.

An additional wire guide 5 is provided inside the nozzle 14 along the axial direction of the nozzle, and the lower end thereof is connected to the additional wire feed tip 12 inclined toward the tungsten electrode 2 with respect to the axial direction of the nozzle. And is connected to an additional wire insulation guide 6 fixed in the power supply chip 3. A wire feed roller 10 driven by a wire feed motor 11 is installed on the upper part of the torch. Through the wire feed roller 10, the addition wire 4 is connected to the addition wire guide 5, the addition wire feed tip 12 and the addition wire. The additional wire 4 is fed to the weld immediately below the tungsten electrode 2 via the wire insulation guide 6.

 Next, the torch tip will be described in detail with reference to FIG.

In the TIG arc welding torch of the present invention, it is desirable to feed the additional wire 4 directly below the arc as much as possible, and the arc length is approximately 3 mm. In this case, if the tungsten electrode 2 and the additional wire 4 are too close to each other, a situation may occur in which the high frequency at the time of the high frequency starts flying to the wire and the wire cannot be started. When this happens, it comes into contact with the tungsten electrode 2 and the welding operation cannot be continued.

Therefore, from the viewpoint of avoiding the above conditions, the shortest distance (r) between the tungsten electrode 2 and the additional wire 4
Are preferably separated by 0.5 mm or more. However, in order to improve the directionality of the torch, the shortest distance (r) between the tungsten electrode 2 and the additional wire 4 is desirably within 2 mm, particularly preferably about 1 mm.

Further, the angle (θ) between the tungsten electrode 2 vertically mounted on the power supply tip 3 located inside the nozzle 1 and the additional wire fed from the inside of the additional wire insulation guide 6 is 2.5 ° The above is desirable. However, considering the directionality of the torch, the angle (θ)
Is preferably within 15 °, and particularly preferably 8 °.

Next, FIG. 6 is a sectional view showing another embodiment of the TIG arc welding torch of the present invention. In this TIG arc welding torch, an annular porous body 35 is arranged between the nozzle 1 and the power supply tip 3c. It differs from the torch of the embodiment in that it is provided.

In a normal torch, in order to enhance the shielding performance, the space inside the nozzle is enlarged and the shielding gas is blown into the space once, and the gas is made laminar from the nozzle tip, or a gas lens made of wire mesh Is introduced into the nozzle to make the gas flow laminar and blown out from the tip of the nozzle.

In the case of the TIG arc welding torch shown in FIG. 6, laminarization of gas is extremely effectively performed. Therefore, laminarization is possible even if the thickness of the porous body 35 is reduced. Since the diameter can be reduced, the size of the nozzle can be reduced.

Next, the operation of the TIG arc welding torch configured as described above will be described with reference to FIGS.

Argon as an inert gas is caused to flow from the tip of the nozzle 1 through a gas flow path 14a formed inside the torch body 14, so that the tip of the tungsten electrode 2 is in an inert gas atmosphere.

In addition, the power supply tip 9 is cooled by the water-cooled conduit 9, and power is supplied to the power supply tip 3 and the tungsten electrode 2 to generate an arc 7 between the tungsten electrode 2 and the workpiece 8. The addition wire 4 is connected to a wire feed motor 11 above the torch.
Wire addition mechanism 5 and an addition wire power supply tip by a pull-type wire feeding mechanism composed of
12, is supplied to the welded portion immediately below the tungsten electrode 2 through the additional wire insulation guide 6.

In such a welding operation, an additional wire insulating guide 6 for supplying the tungsten electrode 2 and the additional wire 4 to the power supply tip 3 is provided, and by feeding the additional wire 4 directly below the arc 7, the wire insertion direction is affected. Omnidirectional that allows welding to proceed in any direction without being performed
TIG welding becomes possible.

In particular, since the power supply tip 3 is provided at the tip of the torch, when the additional wire insulation guide 6 is installed at an angle of 2.5 ° to 15 ° with respect to the tungsten electrode 2, the power supply tip 3 Compared to the case where it is installed inside the nozzle, the added wire insulation guide 6 and the tungsten electrode 2
Is small, which is effective for reducing the size of the nozzle. In addition, since the tip end side of the power supply chip 3 projects so as to be exposed to the flow path of the shield gas, the cooling by the water cooling conduit 9 and the cooling operation by the shield gas can be efficiently performed at the same time.

Further, the wire torch and the arc torch are integrated to form a compact structure, and it is possible to cope with the welding directionality and the welding to a narrow overflow portion, which are problems when the welding torch is mounted on the robot. Further, by inserting the additional wire substantially in parallel with the tungsten electrode 2, the tolerance of the wire insertion position with respect to the change in the arc length is increased.
In addition, one-handed semi-automatic welding, in which an operator performs welding with one hand, can be easily performed.

Next, when the additional wire 4 is inserted substantially parallel to the tungsten electrode 2, when the feeding unevenness of the additional wire 4 occurs, a phenomenon occurs in which the additional wire 4 becomes beaded in the arc plasma. In order to prevent this phenomenon, a pull-type wire feeding mechanism including a wire feeding motor 11 and a wire feeding roller 10 is provided above the torch to prevent uneven feeding of the addition wire 4.

Further, since the addition wire 4 can be fed in accordance with the angle between the addition wire insulation guide 6 at the tip of the addition wire guide 5 and the tungsten electrode 2, even when the addition wire 4 is bent, the addition wire insulation guide 6 can be used. Thus, since the addition wire 4 is forcibly turned to the welded portion, the target position can be made constant.

Further, an addition wire feeding tip 12 is attached to the tip of the addition wire guide 5, and the addition wire guide 5 is covered with an insulating material. When power is supplied from above the addition wire guide, the addition wire feeding tip 12 and the workpiece 8 are connected. A wire heating current flows to the wire 4, and hot wire welding can be performed.

FIG. 7 is an overall schematic configuration diagram of a welding apparatus provided with the above-described TIG arc welding torch. In this welding device, the robot control device causes the robot to output an arm operation control signal for operating the arm. Further, the robot controller causes the controller to output a torch operation control signal in synchronization with the arm operation control signal.

The control device activates an arc power supply based on the torch drive control signal, and causes the arc power supply to flow an arc current between the torch and the workpiece.
Further, the control device activates a wire heating power supply based on the torch drive control signal, and causes a wire heating current to flow between the torch and the workpiece by the wire heating power supply.

FIG. 8 shows the timing of the operation of the addition wire and the supply of the arc current and the wire current flowing between the torch and the workpiece in such a configuration.

In FIG. 8 (A), when the additive wire comes into contact with the workpiece, the additive wire is energized to cause rapid heating and fusing, and the arc is applied only during a period in which the additive wire is separated from the workpiece. Apply TIG welding (hereinafter abbreviated as wire separation HST).

In FIG. 8 (B), a hot wire switching TIG in which the arc current and the wire heating current are pulse-controlled and the additional wire is electrically heated during the base period of the arc current (the arc current is set to a value of 0 A or several tens of A). Welding (hereinafter abbreviated as HST) is applied.

In FIG. 8 (C), the additive wire is made to have a positive polarity and the work to be welded is made to have a negative polarity, and the additive wire is subjected to pulsed electric heating (hereinafter abbreviated as pulse electric heating).

Here, the problem when the additional wire is inserted into the welded portion in the vicinity of the tungsten electrode will be described.

(D) In ordinary TIG arc welding, as shown in FIG. 11, the additional wire 4b is melted by the heat of the arc 7b. Therefore, when the additional wire 4b is inserted almost in parallel with the tungsten electrode 2b, the additional wire 4b Melting ability of
When the number of the additional wires 4b is increased, a phenomenon of pecking the work 8b occurs. That is, the range of the supply amount of the additive wire becomes very narrow.

(E) When the amount of the added wire is small, as shown in FIG. 12, the tip of the added wire 4b becomes spherical in the plasma of the arc 7b, comes into contact with the tungsten electrode 2b, and it becomes impossible to continue welding.

(F) When the additional wire 4b is in contact with the workpiece 8b, the workpiece 8b and the additional wire 4b have the same potential, and an arc is easily formed between the additional wire 4b and the tungsten electrode 2b, and The melting state of the object 8b and the addition wire 4b becomes unstable, and the melting ability of the object to be welded decreases.

Such a phenomenon can be eliminated by the means shown in FIG. That is, the above three means (FIG. 8 (A),
(B) and (C)] are both hot wire welding methods in which the additive wire is heated by energization, and the additive wire can be melted independently of the arc heat. Is gone.

Also, in the wire separation HST of FIG. 8 (A), the arc current is pulsed and the heat input is controlled by a method in which the arc is applied only during a period in which the additive wire is separated from the workpiece, and the additive wire is spherical in the plasma column. It is hard to turn. Also,
Since the arc is cut off when the addition wire is in contact with the workpiece, an arc is not formed between the addition wire and the tungsten electrode.

Next, in the HST of FIG. 8 (B), since the arc current is a pulse current, the additive wire is unlikely to be spherical in the plasma column as described above. In the case of HST, since the difference between the peak value and the base value of the pulse current arc is large, the rigidity of the arc is high, and the arc is rarely formed between the added wire and the tungsten electrode.

In the pulse heating shown in FIG. 8 (C), the addition wire is made to have a positive polarity, the work to be welded is made to have a negative polarity, and the addition wire is heated by a pulse current. Due to this phenomenon, the additive wire is less likely to be spherical in the plasma column, and no arc is formed between the additive wire and the tungsten electrode.

The problems (d), (e) and (d) are solved by means of the above-mentioned FIGS. 8 (A), (B) and (C), and the additive wire is placed as close as possible almost in parallel with the tungsten electrode. Therefore, stable welding can be performed even if the welding is performed just below the arc.

〔The invention's effect〕

According to the present invention, since the welding progress direction can be selected regardless of the insertion position of the addition wire, there is no limitation on the weldable range depending on the insertion position of the addition wire, which is particularly problematic when the robot is mounted. Teaching can be performed regardless of the insertion direction, so teaching time can be reduced.

Since the wire torch and the arc torch are integrated and only the arc torch is used, it is possible to weld a narrow overflow portion, which could not be welded by the conventional wire torch.

The tolerance to the change in arc length, which is a problem in TIG welding, is increased, and deformation of the work piece due to distortion during welding can be prevented.

From the above, the welding range can be expanded, especially when the robot is mounted, the teaching time can be shortened, and high quality welding without spatter can be performed because rough teaching can be performed, and the TIG welding robot can be applied. This has the effect of expanding the range.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing an embodiment of a TIG arc welding torch of the present invention, FIG. 2 is a side view of FIG. 1, and FIG.
4 and 5 are transverse sectional views showing the structure of the water-cooled conduit in FIG. 1, and FIG. 6 is a TI of the present invention.
FIG. 7 is a cross-sectional view showing another embodiment of the tip of the torch in the G arc welding torch, FIG. 7 is a schematic configuration diagram of the welding apparatus of the present invention, and FIGS. FIG. 9 is a schematic configuration diagram of a conventional TIG arc welding torch, FIG. 10 is an enlarged sectional view of a main part of FIG. 9, and FIGS. 11 and 12 are arc welding. FIG. DESCRIPTION OF SYMBOLS 1 ... Nozzle, 2 ... Tungsten electrode, 3 ... Feeding tip, 4 ... Addition wire, 5 ... Addition wire guide, 6
... Additional wire insulation guide, 7 ... Arc, 8 ... Workpiece to be welded, 9 ... Water-cooled conduit, 10 ... Wire feeding roller, 11 ...
… Wire feeding motor, 12 …… Additional wire feeding tip, 13
…… Insulation cover, 14 …… Torch body, 35 …… Porous body.

Continuation of the front page (56) References JP-A-52-98648 (JP, A) JP-A-51-31650 (JP, A) JP-A-63-180376 (JP, A) JP-A-61-186172 (JP, A) JP-A-58-138569 (JP, A) JP-A-52-58039 (JP, A) JP-A-48-112822 (JP, U) JP-A-52-113838 (JP, U) (58) Field surveyed (Int.Cl. ⁶ , DB name) B23K 9 / 12,9 / 167,9 / 26 B23K 9/29

Claims (10)

(57) [Claims] 1. A non-consumable tungsten electrode protruding from a tip of a nozzle provided with a water-cooling conduit having conductivity therein is held in a vertically fitted state, and is connected to the water-cooling conduit to be connected to the water-cooling conduit. A power supply tip that is cooled and energized via the power supply tip, an annular shield gas supply flow path formed on the outer peripheral side of the power supply tip, an addition wire guide provided inside the nozzle, and a power supply tip. And an additional wire insulation guide formed of an insulating material, wherein a direction in which the additional wire is supplied from the additional wire insulation guide has an angle with respect to the non-consumable tungsten electrode. And TIG arc welding torch. 2. The angle between the non-consumable tungsten electrode and the additional wire fed from the inside of the additional wire insulation guide.
The TIG arc welding torch according to claim 1, wherein the angle is 2.5 ° to 15 °. 3. The TIG arc welding torch according to claim 1, wherein a nozzle tip side of the power supply tip projects so as to be exposed to the shield gas supply flow dew. 4. The addition wire guide according to claim 1, wherein the addition wire guide is made of a conductive member, and the addition wire between the power supply tip and the workpiece is electrically heated. TIG arc welding torch. 5. The water-cooled conduit has two flow paths formed in the pipe by a partition surface along the axial direction, cooling water is introduced from one flow path side, and after reaching the power supply chip, the other flow path is formed. The TIG arc welding torch according to claim 3, wherein the torch has a structure that is discharged from a road. 6. The TI according to claim 1, wherein a pull-type wire feeding mechanism is provided above the torch.
G arc welding torch. 7. A TIG arc welding torch according to any one of claims (1) to (6), wherein the TIG arc welding torch is electrically heated to melt the addition wire independently of arc heat. A welding apparatus, comprising: 8. The welding apparatus according to claim 7, further comprising a control mechanism for energizing the arc in a pulsed manner only during a period in which the additive wire is separated from the workpiece. 9. The welding apparatus according to claim 7, further comprising a control mechanism for energizing the arc in a pulsed manner and for energizing the additional wire in response to the base of the pulsed current arc. 10. The welding apparatus according to claim 7, wherein the addition wire has a positive polarity, the work to be welded has a negative polarity, and a control mechanism for heating the addition wire with a pulse current is provided.