JPS63144872A - Semiautomatic tig welding equipment for hot wire - Google Patents

Abstract

PURPOSE:To improve the welding quality and the working efficiency by providing a means to detect automatically the contact of base metal with a wire and changing over an arc current based on a detected signal. CONSTITUTION:A touch detection circuit 23 is provided to the inside of a wire heating power source circuit 19 and a wire feed control circuit 24 is arranged to a wire feeder 17. On the other hand, an arc current control circuit 27 connected with the control circuit 24 is installed on the inside of a TIG arc power source 3. The touch detection circuit 23 detects whether or not the tip of an additional wire 5 is in contact with the base metal 2 during TIG welding and a result is outputted to the wire feed control circuit 24. The arc current control circuit 27 changes over from a starting current from a main welding current in receipt of a signal from the control circuit 24 and then, changes over from the main current to a crater processing current. In this way, since an arc can be prevented from deflecting, the welding quality is improved and the working efficiency is also improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a welding device, and particularly to a welding device suitable for performing semi-automatic hot wire TIG arc welding.

[Conventional technology]

FIG. 3 shows an example of the configuration of a conventional automatic hot wire TIG welding device.

The device with this configuration is configured to supply the additive wire while heating it with electricity. That is, an arc power source 3 for welding is directly connected to the tungsten electrode 1 and the base material 2, and an arc 4 is formed with the tungsten electrode 1 as a negative electrode in a shielding gas such as argon. The additive wire 5 is passed from the wire feeding device 6 through a wire guide 9 consisting of a conduit 7 and a contact tip 8 connected to the conduit door, and is blown into the arc generating section and comes into contact with the base material 2. In this case, a wire power source 10 is connected between the contact tip 8 and the base material 2,
Direct current or alternating current is passed through the additive wire 5 to generate Joule heat, thereby increasing the melting rate of the additive wire 5.

With this device, when deposited metal is required for normal manual TIG welding, hold an additive rod with a diameter of 2.4 mm and a length of about 600 mm in your left hand, and hold a TIG arc torch in your right hand. Then, the welding process progresses while manually supplying the metal to be welded. On the other hand, automatic TI
In the case of G welding, the additive metal is supplied by a wire feeding device that automatically feeds the wire using a motor, but the wire guide and TIG arc torch are both fixedly held on a stand, etc., and then welded. Welding is performed by mounting it on a trolley, etc.

A semi-automatic TIG welding device is provided as an intermediate device between the manual type and automatic type described above.

FIG. 4 shows details of the torch holder of a commercially available semi-automatic welding torch currently in use.

In this configuration, a wire guide 9 is semi-fixedly attached to a hand-held TIG torch main body 11 by an attachment means, and the additive wire 5 is automatically fed at a predetermined speed by a wire feeding device (not shown). Ru. Since the tip of the additive wire 5 needs to be added at the correct position in the molten pool 12 formed by the arc 4, it is necessary to adjust the wire addition position with respect to the means for attaching the TIC)-chi body 11. An adjuster 13 is provided.

The operator holds the torch main body 14 configured as described above in his right hand, and while adjusting the torch position, operates a remote control knob of a wire feeding device (not shown) with his left hand to adjust the wire feeding speed. Generally, to start and stop wire feeding, a switch 15 is provided near the holding part of the welding torch, and the switch 15 is operated with the fingertips of the same right hand while holding the welding torch with the right hand. .

FIG. 2 shows the operating sequence of this conventional semi-automatic TIG welding device.

First of all, by pressing the switch 15 provided near the holding part of the welding torch, the arc current at the time of starting the device starts flowing 1. By releasing the torch switch 15, wire feeding starts, and then the wire current starts flowing. , the wire feeding speed gradually increases and is kept at a constant value in terms of Q. At the end of welding, the wire feeding is stopped by pressing the torch switch 15 again, and the wire current decreases accordingly, and after a predetermined period of time, the arc current value for crater treatment is reached, and when the torch switch 15 is further released, the wire feeding is stopped. The current is stopped and the welding operation is completed.

[Problem that the invention seeks to solve]

As specifically shown above, in conventional equipment,
All operations of the device are performed by turning the torch switch 15 ON and OFF. At this time, there is a possibility that the operation of turning the torch switch 15 on and off may have a negative impact on the welding work. Immediately, this torch switch 15 is connected to the welding torch 11.
It is located near the p holding part, and switching is performed by pressing this switch or releasing this suppressed state, so when switching with the switch, the electrode located at the tip of the torch There have been problems in that the arc may oscillate and come into contact with tungsten, or the arc may be too thick and the bead formation may be disturbed.

[Means for solving problems]

The above-mentioned problem is that the work is switched by a switch, which causes torch deflection, so this switch has been abolished, and a signal indicating whether or not the wire is in contact with the base material is output, and this signal is used. The process of welding work is switched according to the following.

[Effect]

Upon receiving a signal that the wire has contacted the base metal, the device switches the arc current at the start to the arc current during the main welding. In addition, the arc current during main welding is switched to the arc current for crater treatment in response to a signal indicating that the wire has separated from the base metal.

〔Example〕

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

In FIG. 1, reference numeral 16 denotes a T having the same structure as the conventional structure.
IG arc welding torch, 17 is a wire feeding device, 18 is a conduit, 19 is a wire heating power source, 20 is a current-carrying cable, 21 is a wire torch, 22 is a contact tip, 23 is a touch detection circuit, 24 is a wire feeding Control device,
25 is a tungsten electrode, 26 is a 'mm reverse feed circuit 27
is the arc current control circuit.

First, the TrG arc welding torch 16 is connected to the TIG arc power source 3 to form the TIG arc 4. In this case T
Both the IG arc welding torch 16 and the TIG arc power source 3 are conventional devices with conventional configurations. The additive wire 5 is supplied from a wire feeder 17 via a conduit 18, and the negative output of a 7V source 19 for heating the wire is sent via an energizing cable 20 to a wire torch 21. The additive wire 5 exits the wire torch 21, contacts the base material 2 connected to the positive output of the wire heating power source 19 that outputs a pulsed current, and is heated and melted by electricity between the contact tip 22 and the base material 2. . The output voltage of the wire heating power source 19 is determined by the detection circuit built into the wire heating power source 19, that is, the touch detection circuit 23 (
(Japanese Patent Application No. 61-30649). This touch detection circuit 23 detects whether the tip of the additive wire is in contact with the base metal during TiG welding, and in hot wire TIG welding in which the wire is heated using pulsed current, the instantaneous value of the wire current is detected. The purpose is to obtain information on the presence or absence of wire contact from the voltage between the base material and the tip of the wire when is zero. That is, when the tip of the wire is in contact with the base material, the plasma potential is detected, and when the tip of the wire is separated from the base material and floating in the arc plasma, the plasma potential is detected. It detects whether or not it is in contact with the base material. The result detected by this touch detection circuit 23 is transmitted to the wire feeding control device 2 of the wire feeding device 17.
Output to 4. In this control device 24, the wire 5 is
When it receives a signal indicating that it has touched the wire, it interprets it as a signal instructing it to feed the wire, and feeds the wire.
If the wire remains separated from the base material for one second or more, it is interpreted as a signal to stop feeding the wire, and the feeding of the wire is stopped.

Similarly, the arc current control circuit 27 receives wire feeding start and feeding stop signals from the control device 24 of the wire feeding device 17. When receiving the signal to "start wire feeding work," the arc current is gradually increased from the starting arc current to the arc current value for main welding. On the other hand, when receiving the "stop wire feeding" signal, the arc current is gradually lowered to an arc current value for crater treatment.

If this work is actually performed by a worker, follow the steps below.
done in a manner.

The worker holds a TIG arc torch 16 in his right hand and a wire torch 21 in his left hand. The tip of the tungsten electrode 25 of the arc torch is brought into contact with the base material 2 to transmit an arc start signal to the arc current, and the arc is then started in a normal manner.

When the melting of the base material 2 progresses and a sufficiently large molten pool is formed, the wire torch 21 held in the left hand is brought close to the base material and the tip of the wire 5 is brought into contact with the molten pool. As a result, in response to this contact signal, °ζ wire feeding is started, and at the same time, the arc current gradually rises and is maintained at a melting current, and in the same way, electricity is supplied from the wire heating power source 19, and hot wire welding is performed. will be implemented.

Next, when the wire torch 21 is separated from the base material 2 at the end of welding, the touch detection circuit 23 detects that the wire has separated from the base material 2 and outputs a signal accordingly. In response to this signal, wire feeding and wire current are stopped, the arc 11 current is gradually lowered to become an arc current for crater treatment, and further, this arc 11 flow is stopped after crater treatment.

〔effect〕

Since the present invention has the above-described configuration, the current can be automatically switched from the start current to the welding current and from the welding current to the crater treatment current according to the work process without using a torch switch. Welding quality can be improved without causing problems such as arc deflection, and welding efficiency can also be improved.

[Brief explanation of the drawing]

FIG. 1 is a semi-automatic hot wire TI showing an embodiment of the present invention.
A conceptual diagram showing the configuration of the G welding device, FIG. 2 is a conceptual diagram showing the work sequence during welding, and FIG. 3 is a conceptual diagram showing the configuration of a conventional semi-automatic hot wire TIG welding device.
FIG. 4 is a partially detailed view of the apparatus shown in FIG. 3. 16... Welding torch 17... Wire feeding device
19... Wire heating power source 21... Wire torch 23... Touch detection circuit 24... Wire feed control circuit 25... Tungsten electrode 27... Arc current control circuit Fig. 1 Fig. 2 figure

Claims (1)

[Claims] In a welding device consisting of a welding arc power source, an arc torch, a wire heating power source, a wire feeding device, and a wire feeding torch, there is provided a means for detecting whether or not a wire is in contact with a base material, and a means for detecting whether or not a wire is in contact with a base material. Means for switching the arc current from the starting value to the value for main welding by a signal indicating that the wire has separated from the base metal, and means for switching the arc current from the value for main welding to the value for crater treatment by a signal indicating that the wire has separated from the base metal. A semi-automatic hot wire TIG welding device comprising: