JPH03210968A - Electric source apparatus for hot wire tig welding - Google Patents

Abstract

PURPOSE:To surely generate arc even when a wire approaches an electrode by winding two coils in the same direction and the same number of turns at secondary side in high frequency coupling coils and connecting each coil to output circuit of TIG arc current and output circuit of wire heating current, respectively. CONSTITUTION:By starting a high frequency generator 4, the high frequency and high voltage are generated to the coupling coils 6. By this method, insulation between a tungsten electrode 11 and a base material 15 is broken to generate the arc. At this time, the output of TIG arc current and the output of wire heating current are connected with two secondary coupling coils closely and doubly wound in the same direction and the same number of turns, respectively, and the tungsten electrode 11 and tip part of the filler wire 12 are charged to the level of completely same phase and same potential. Therefore, the current does not flow into between the tungsten electrode 11 and the filler wire 12. By this method, high frequency spark is generated between the electrode and the base material having low potential, even in the case the wire 12 is positioned at any neighborhood of the electrode 11, and the arc is surely generated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a hot wire TIG welding power supply device, and particularly to a hot wire TIG suitable for performing arc start well.
This relates to an lG1 connected power supply device.

[Conventional technology]

FIG. 3 schematically shows the configuration of a conventional hot wire welding machine. Hot wire welding electric current a1 is mainly T
It consists of a TIG power supply unit 2 that supplies IG arc current, a wire heating power supply unit 3 that supplies wire heating current, and a high frequency generator 4 that causes dielectric breakdown between tungsten electrode 11 and base material 15 at the time of arc start. .

The output of the TIG current is connected to the TIG torch 10 and the base material 15 through an arc power cable 16 and a welding ground cable 18 to supply current. The wire heating current output is
It is connected to the wire feeder 14 by a wire power cable 17 and is supplied to the filler wire 12 via the wire conduit cable 19 and the contact tip 13 to heat the wire.

The high frequency generator 4 for igniting the arc includes a transformer 5, a coupling 6, a capacitor 7, a discharge gap 8, etc. When the high frequency generator 4 is started, a voltage of several thousand ports is generated on the secondary side of the transformer 5, which starts charging the capacitor 7. When the terminal voltage rises to the discharge starting voltage of the discharge gap 8, the capacitor 7 The charges stored in the capacitor 7 are discharged to the coupling coil 6 through the discharge gap 8, and then the capacitor 7 starts charging again and repeats the discharge. As a result, an oscillation circuit with a frequency of MHz is constructed, spark discharge is started between the tungsten electrode 11 and the base material 15, and TIG
If the power supply section 2 is activated and voltage is applied, this will induce arcing. Further, a bypass capacitor 9 is provided on the output side of the TIG power supply section 2 and the wire heating power supply section 3, and protects the internal semiconductors by preventing the high frequency high current generated at the time of arc start from flowing into the power supply.

By the way, in normal hot wire TIG welding, the filler wire 12 is often inserted obliquely from the front or rear, as shown in the torch section of FIG.

However, when the shape of the workpiece is complex and it is difficult to insert the torch, the filler wire 12 is connected to the electrode 1 as shown in FIG.
It may be inserted almost parallel to 1.

Since high-frequency sparks are generated closest to the tungsten electrode 11, when the high-frequency generator is started in this state, high-frequency sparks are generated from the electrode 11 toward the filler wire 12.

That is, the high-frequency current path is explained with reference to FIG. 3. The high-frequency current path is transmitted as a high-frequency spark from the tungsten electrode 11 to the filler wire 12 via the coupling coil 6 and the arc power cable 16, and is connected to the contact tip 13 - wire power cable 17 - wire heating power supply section. Bypass capacitor 9 connected to 3 Welding ground cable 18-TIG power supply section 2
It returns to the coupling coil 6 from the bypass capacitor 9 connected to the . As a result, tungsten electrode 1
Since no high-frequency spark is generated between the base material 1 and the base material 15 and no dielectric breakdown occurs, an arc cannot be ignited.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, in hot wire TIG welding, when the filler wire is close to the tungsten electrode, high frequency waves for arc starting are generated between the electrode and the wire,
There was a problem in that the insulation between the electrode and the base material could not be broken, and the arc could not be ignited.

An object of the present invention is to provide a hot wire TIG welding power source that can reliably ignite regardless of the positional relationship between the filler wire, tungsten electrode, and base material.

[Means to solve the problem]

The above object is achieved by making the potential of the filler wire in phase with the tungsten electrode when generating high frequency waves for ignition. Further, the above object is achieved by inserting a reactor or a switch to shut off the high frequency current from entering the wire side output terminal of the wire heating power source when generating the high frequency wave for ignition.

[Effect]

Current has the property of flowing from higher potential to lower potential.

Therefore, if the potential of the tungsten electrode and the filler wire are always the same, or if the circuit connected to the filler wire is in a high impedance state with respect to high frequencies, no current will flow from the electrode to the wire, and the high frequency spark will Generates toward the wood. In this way, ignition can be ensured regardless of the positional relationship between the electrode, wire, and base material.

[Embodiments of the invention]

(i) Overall configuration FIG. 1 shows a configuration diagram of a hot wire TIG welding power source according to the present invention.

Hola 1-Wire TIG welding type #1 is almost the same as the conventional hot wire TIG welding power source shown in Fig. 3, and includes a TIG power source section 2, a wire heating power source section 3, a high frequency generator 4, a TIG power source, and a wire heating power source. It has a bypass capacitor 9 for protection from high voltage, and its power output is connected to a welding torch 10, a contact tip 13, and a base material 15 to supply current.

The principle of the high-frequency generator 4 for ignition is the same as that described in the prior art, but in the present invention, the coupling coil 6 is provided not only in the TIG current supply section but also in the wire current supply section. It has characteristics. That is, the coupling coil 6 has two secondary windings, one connected to the TIG current output path and the other connected to the wire current output path. Further, the two secondary coils have the same direction and the same number of turns, so that the generated secondary voltages are as in-phase and at the same potential as possible.

(11) Interrelationship and operation of each component in the hot wire TIG welding power source of the present invention shown in FIG.
The arc ignition method at the start of welding is the same as the method described in the conventional method.

That is, by starting the high frequency generator 4, a high frequency high voltage is generated in the coupling coil 6. This destroys the insulation between the tungsten electrode 11 and the base material 15 and generates an arc. At this time, the output of the TIG arc current and the output of the wire heating current are respectively connected to two secondary coupling coils tightly wound in the same direction and with the same number of turns. The tips are completely in-phase and at the same potential. Therefore, no current flows between the tungsten electrode 11 and the wire wire 12, and high-frequency sparks are generated between the wire 12 and the base material, which has a low potential, no matter how close the wire 12 is to the electrode 11.

Therefore, at the start of welding, if a voltage is applied between the electrode 11 and the base metal 15 with only the TIG power supply section 2 activated, and the wire heating power supply section 3 is stopped, when the high frequency generator 4 is activated, the wire wire 12 Even if the wire is close to the tungsten electrode 12, if the tungsten electrode is closer to the base metal than the wire wire, high frequency sparks will be generated between the electrode 11 and the base metal 15, and an arc can be generated.

Another embodiment of the invention is shown in FIG.

In this embodiment, the secondary side of the coupling coil 6 of the high frequency generator 4 is the same as the conventional power supply shown in FIG. are doing.

When the high-frequency generator 4 is started, if the wire 12 is closer to the electrode 11 than the base material 15, an attempt is made to generate a high-frequency spark between the electrode and the wire, but the reactor 20
Since the high-frequency current is blocked and no current can flow, a high-frequency wave is generated between the electrode and the base material and ignites the arc.

Further, the same effect can be obtained by connecting an electromagnetic contactor in place of the reactor 20 shown in FIG. 2, and when generating high frequency waves, by keeping the electromagnetic contactor open and cutting off the wire current path by δ.

J Effects of the Invention] According to the present invention, the arc can be reliably ignited even if the wire wire is close to the tungsten electrode, so there is no need to make adjustments such as moving the wire away from the tungsten electrode each time welding starts. Good too. Furthermore, since high-frequency sparks are no longer emitted unnecessarily, there is no possibility of peripheral electronic circuits malfunctioning due to noise.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the configuration of a hot wire TIG welding power source according to the present invention, Fig. 2 is a diagram showing another embodiment that provides the same effect as Fig. 1, and Fig. 3 is a diagram showing a conventional hot wire TIG welding power source.
FIG. 4 is a diagram showing the configuration of the welding power source, and is a diagram showing the positional relationship between the electrode and wire in the welding torch section. ■...Hot wire TIG welding power source, 2...TIG
Power supply unit, 3... Wire heating power supply unit, 4... High frequency generator, 6... Coupling coil, 20... Reactor. Figure 2

Claims (3)

[Claims] (1) In a hot wire TIG welding power supply device equipped with a power supply that supplies TIG arc current, a power supply that supplies current to and heats the filler wire, and a high-frequency generator for arc generation, the secondary side of the high-frequency coupling coil A hot wire TIG welding power supply device characterized in that two coils are wound in the same direction and with the same number of turns, and each is connected to an output path of a TIG arc current and an output path of a wire heating current. (2) In a hot wire TIG welding power supply device that is equipped with a power supply that supplies TIG arc current, a power supply that supplies current to and heats the filler wire, and a high-frequency generator for arc generation, high frequency is used in the output path of the wire heating current. A hot wire TIG welding power supply device characterized by being provided with a reactor for current interruption. (3) In a hot wire TIG welding power supply device equipped with a power supply that supplies TIG arc current, a power supply that supplies current to and heats the filler wire, and a high-frequency generator for arc generation, there is a switch in the output path of the wire heating current. A hot wire T characterized in that a switch is provided, and when high frequency is generated, the switch is opened to prevent high frequency current from flowing to the wire heating power source side.
IG welding power supply device.