JPH08309540A - Semi-automatic tig welding equipment - Google Patents

Abstract

PURPOSE: To provide a semi-automatic TIG welding equipment capable of frequent feeding/stopping of filler wire during arcing. CONSTITUTION: An equipment is provided with a wire feeding device 3 to execute feeding/stopping of a filler wire 9, an arc power unit 1 to impress arc voltage and arc voltage detecting means 23a, 23b to detect arc voltage. Further the equipment is provided with a reference voltage setter 24 to set reference voltage and a feeding controller 22 in which by comparing the arc voltage detected with the arc voltage detecting means 23a, 23b and the reference voltage set with the reference voltage setter, in the case arc voltage is lower than reference voltage, filler wire feeding signal is outputted, in the case arc voltage is higher than reference voltage, feed stopping signal is outputted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semi-automatic TIG welding device, and more particularly to a feed control device for an additive wire of the welding device.

[0002]

2. Description of the Related Art FIG. 4 shows a schematic structure of a conventionally known semi-automatic TIG welding apparatus held in one hand.

A TIG arc power source 1 and its remote control box 2,
Additive Wire Feeding Device 3 and Additive Wire Feeding Control Device 4
A semi-automatic TIG welding device is composed of the remote control box 5, the TIG torch 6, the base metal 7, and the like. The adding wire feeding device 3 is composed of a feeding motor, a feeding roll, an adding wire reel, etc., which are not shown, and the conduit 8
The addition wire 9 is fed to the TIG torch 6 through.

The TIG torch 6 is a tungsten electrode 1
0, shield gas nozzle 11, torch body 12, addition wire guide 13 and attachment member 14 for attaching it to the outside of the TIG torch 6, torch switch 15 for turning on / off the arc 17 and addition wire feed, arc power supply The side and the arc current cable, the shield gas hose, the cooling water inlet / outlet hose, the cable sheath 16 including the signal cables such as the torch switch 15 and the like.

A cable 18 is provided between the arc power source 1 and the base material 7.
Connected by. In the figure, illustration of the cooling water system and the shield gas system is omitted.

Tungsten electrode 1 in TIG torch 6
0 and the base material 7 are connected to the arc power source 1 for DC welding, and the tungsten electrode 10 is used as the negative electrode in the argon shield gas, and the base material 7 is used as the anode to form the arc 17. The dosing wire guide 13 moves integrally with the TIG torch 6 via a mounting member 14.

A normal welding sequence of this semi-automatic TIG welding apparatus will be described with reference to FIG. First, the operator presses the torch switch 15 at t ₁ to generate a high frequency for starting an arc, and at the same time, an arc voltage is applied to cause an arc current to flow. When the torch switch 15 is released at t ₂ , the arc current gradually increases to the value set as the welding current. At the same time, the feeding of the dosing wire is started, as indicated by the dosing wire speed (1). Although the welding proceeds in this way, when the torch switch 15 is pressed at t ₃ , the feeding of the additive wire is stopped, the arc current is gradually reduced to the value set as the crater current, and then at t ₄ , the torch is cut. When the switch 15 is released, the arc current supply is stopped and the arc is extinguished. The welding current and the speed of the added wire are set or changed by the volumes in the remote control boxes 2 and 5 before or during welding.

Since the sequence shown in FIG. 5 is normally followed by operating one torch switch 15 in this manner, the feeding of the additive wire cannot be interrupted or restarted during welding. Therefore, another torch switch 19 may be provided for feeding / stopping the addition wire. The wire speed (2) in FIG. 5 is set such that during the previous sequence execution, the wire feeding is stopped while the torch switch 19 is on, and when the torch switch 19 is turned off, it returns to the value in the original sequence. This is an example of control.

In this way, the two torch switches 15, 1
9 can be used to feed and stop the additive wire 9 during welding, but a push button type torch switch 15,
When pushing 19 with a finger, the tip of the TIG torch 6, that is, the tip of the tungsten electrode 10 is likely to move laterally from the weld. In particular, the operation of pressing the two torch switches 15 and 19 differently moves the finger greatly, and the TIG
The position of the arc is often unstable due to the displacement of the torch 6. For this reason, the torch switch 15,
Manipulating 19 is impractical and rarely used in practice.

In the conventional semi-automatic TIG welding apparatus, as shown in FIG. 4, the addition wire 9 is inserted obliquely outside the TIG torch 6 along the base metal 7 as much as possible. For this reason, the circumference of the TIG torch 6 becomes bulky and it becomes difficult to perform welding in a narrow space. Moreover, since the additive wire 9 is inserted from the lateral direction, the position of the tip of the wire largely shifts when the arc length changes, which makes it difficult to keep the welding state constant. Therefore, if the arc length is kept constant, the welding operation is It will be very difficult. From the above, semi-automatic TI
The reality is that G welding equipment has not been put to practical use.

[0011]

In semi-automatic TIG welding, there are cases where the amount of deposited metal should be reduced to achieve deeper penetration, or a large amount of deposited metal is required.
For that purpose, it is necessary to be able to freely adjust the wire addition amount, and in order to make such adjustment possible, it is necessary to easily feed and stop the addition wire. However, in the conventional semi-automatic TIG welding device, it is complicated to frequently feed and stop the additive wire with the torch switch during welding as described above, and it is not practical because of the shaking caused by the operation. Welding condition cannot be obtained.

In order to reduce the size of the torch,
Then, in order to stabilize the wire insertion position, if the additive wire is inserted along the tungsten electrode, and if the wire melting is delayed for some reason, the wire hits the base metal and stretches, lifts the torch and continues the welding work. It has the drawback that it cannot be performed.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide a semi-automatic TIG welding apparatus capable of frequently supplying and stopping the additive wire even when an arc is generated.

[0014]

In order to achieve the above-mentioned object, the present invention provides a device for feeding and stopping an additive wire between a wire feeding device and a non-consumable electrode such as a tungsten electrode. An arc power source for applying an arc voltage, an arc voltage detecting means for detecting an arc voltage, a reference voltage setting device for setting a reference voltage, and an arc voltage detected by the arc voltage detecting means during a wire feeding permission period. When the arc voltage is lower than the reference voltage, the additive wire feed signal is output, and when the arc voltage is higher than the reference voltage, the additive wire feed temporary stop signal is output. And a feed control device for outputting.

[0015]

The present invention has the above-described structure, and the operator sets the reference voltage to a value slightly higher than the arc voltage when welding is performed by adding the wire, and the arc voltage detecting means is used. Detect the arc voltage. Then, during welding, the arc voltage and the reference voltage are input to the comparison circuit, and the magnitudes of their absolute values are compared. As a result, when the arc voltage is lower than the reference voltage, the additive wire feed command signal is output to the feed motor drive circuit, and when the arc voltage is higher than the reference voltage, the add wire feed command is sent to the feed motor drive circuit. Outputs a pause signal to pause.

The worker performs welding work while adding and melting the additive wire at an arc voltage suitable for the work, and when it is desired to temporarily stop the addition of the wire, the arc length can be made slightly longer to increase the arc voltage. The wire addition can be suspended while the material continues to melt.

When the wire addition is restarted, if the arc length is shortened and the arc voltage is made lower than the reference voltage, the addition wire is fed. In this way, it is possible to easily feed and stop the additive wire only by changing the arc length by the TIG torch held by the hand.

[0018]

【Example】

(First Embodiment) FIG. 1 is a schematic configuration diagram of a semi-automatic TIG welding apparatus including an additive wire feed control device according to a first embodiment of the present invention, and FIG. 2 illustrates a welding sequence of the additive wire feed control device. It is a timing chart for doing.

In FIG. 1, a TIG torch 21 is a one-hand semi-automatic modification of the automatic welding torch of Japanese Patent Laid-Open No. 3-297574 proposed by the present inventors. , The tungsten wire 10 is delivered to the arc generating portion in the vicinity thereof and along the same, so that the additive wire 9 enters from the direction perpendicular to the surface of the base material 7. The addition wire feed control device 22 inputs the arc voltage detected by the arc voltage detection lines 23a and 23b, and also receives an input signal from the reference voltage setting device 24 placed by the welding operator, and the arc power supply 1 In response to the control input signal from the controller, the additive wire feeding device 3 is controlled.

The addition wire feed control device 22 has a function of outputting to the feed motor drive circuit in the addition wire feed device 3 as well as
Arc power supply 1 based on the signal from the torch switch 15
A microprocessor (not shown) in the controller for input signals such as an additive wire feed permission signal 25, an arc voltage 26, and a reference voltage 27 (see FIGS. 2 and 3) created by a welding controller (not shown) in the controller. In the end, while the addition wire feed permission signal 25 based on the torch switch 15 is turned on, the addition wire 9 is fed or the wire feeding is temporarily stopped depending on the result of comparison between the arc voltage 26 and the reference voltage 27. Is configured to output a signal that

Next, the welding work sequence including the operation of the additive wire feed control device will be described with reference to FIG. First, before starting the welding operation, the arc current, the feeding speed of the additive wire, the reference voltage 27 and the like are set to appropriate values by using the remote control boxes 2 and 5 at hand, the reference voltage setting device 24 and the like.

[0022] then the welder torch switch 1 t ₁
5 is pressed to generate a high frequency for starting an arc, and at the same time, an arc voltage 26 is applied to flow an arc current. When the torch switch 15 is released at t ₂ , the arc current gradually increases to the value set as the welding current. At the same time the arc voltage 26
Is lower than the reference voltage 27, the feeding control device 22 starts feeding the additive wire as indicated by the wire speed. Welding proceeds in this way, but at t ₅ , TIG
When the torch 21 is slightly separated from the base material 7 and the arc length is made slightly longer, the arc voltage 26 becomes higher than the reference voltage 27, and the feed control device 22 detects that and the feed wire feeding is temporarily stopped.

Next, at t ₆ , the arc length is slightly shortened and the arc voltage 26 is made lower than the reference voltage 27, and the feed control device 22 detects this and restarts the feeding of the addition wire 9. In this way, the worker can feed or stop the addition wire 9 during the welding work only by lengthening the arc length so as not to hinder the work or returning it to the original position.

Finally, when the torch switch 15 is pushed at t ₃ , the wire feeding is stopped, the arc current is gradually reduced to the value set as the crater current, and then at t ₄ , the torch switch 15 is released to release the arc current. Supply is stopped and the arc is extinguished. In addition, welding current, added wire speed, reference voltage 2
7 is a variable resistor in the remote control boxes 2 and 5 and the reference voltage setting device 24, the value of which can be arbitrarily changed during welding.

The reference voltage 27 is practically selected to be higher than the proper arc voltage for feeding and feeding the additive wire 9 by about 0.7 V, which is an arc length change amount of 1 to 2 mm. It will change to some extent.

In the case of the present embodiment, the addition wire 9 is misconfigured.
When the wire feeding speed is set to be higher than the melting speed of T, the T added to the base material 7 by the addition wire 9
The IG torch 21 is lifted, and as a result, the arc length becomes longer, the arc voltage 26 becomes higher than the reference voltage 27, the wire feeding is stopped, and the addition wire 9 waits for the melting to proceed. That is, there is an advantage that even if the additive wire 9 is inserted vertically into the surface of the base material 7, the situation in which the TIG torch 21 is not lifted to a state in which it cannot be welded is achieved.

(Second Embodiment) The structure of the semi-automatic TIG welding apparatus is the same as that of the first embodiment, but as shown in FIG. 3, the arc voltage 26 is applied during the period when the feed permission signal 25 is on.
Is higher than the reference voltage 27, wire feeding is stopped from feeding, or switching from stop to feeding is performed.

In the case of this embodiment, the reference voltage 27 is set slightly higher than that in the case of the first embodiment, and when the wire feeding / stopping is switched, the arc length is momentarily lengthened. Immediately after that, the arc length can be shortened back to a state suitable for work. That is, there is an advantage that the arc length can be shortened even during the wire stop period.

(Third Embodiment) Semi-automatic TIG of the first embodiment.
When a welding apparatus is used and a low pulse arc current is used, the arc voltage 26 during the peak current period is high and the arc current during the base period is low, so the reference voltage 27
If is kept constant, there may occur a situation in which the feeding is stopped during the peak current period and is fed during the base period.

Therefore, by controlling the wire feeding / stopping by comparing the arc voltage 26 and the reference voltage 27 only during the peak current period, the semi-automatic TIG welding of the present invention can be performed even in the case of a low pulse arc current. The device can be used as it is. In this embodiment, the arc voltage during the peak current period is targeted for control, but similarly, the arc voltage during the base current period may be targeted for similar control.

[0031]

According to the present invention, it is possible to control the feeding / stopping of the additive wire by slightly approaching or separating the torch from the base metal during arc generation, so that the torch switch is used to feed the additive wire. -Semi-automatic TIG welding work becomes easier because there is less shaking of the non-consumable electrode than when stopped, and frequent feeding / stopping operations can be performed. As a result, more preferable beads can be formed, and the occurrence of welding defects is reduced.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a semi-automatic TIG welding apparatus according to a first embodiment of the present invention.

FIG. 2 is a timing chart for explaining a welding sequence of the semi-automatic TIG welding device.

FIG. 3 is a timing chart for explaining a welding sequence of the semi-automatic TIG welding apparatus according to the second embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of a conventional semi-automatic TIG welding apparatus.

FIG. 5 is a timing chart for explaining a welding sequence of the semi-automatic TIG welding apparatus.

[Explanation of symbols]

 1 Arc power supply 3 Additive wire feeder 7 Base material 9 Additive wire 10 Tungsten electrode 17 Arc 21 TIG torch 22 Feed controller 23a, 23b Arc current detection line 24 Reference voltage setting device 25 Feed permission signal 26 Arc voltage 27 See Voltage

Claims (1)

[Claims] 1. A wire feeding device for feeding and stopping an additive wire, an arc power source for applying an arc voltage between a base material and a non-consumable electrode, and an arc voltage detecting means for detecting an arc voltage. , A reference voltage setting device for setting a reference voltage, and during the wire feed permission period, the arc voltage detected by the arc voltage detecting means and the reference voltage set by the reference voltage setting device are compared to obtain an arc voltage. Is lower than the reference voltage, the feeding wire feeding signal is output when the arc voltage is higher than the reference voltage, and a feeding control device that outputs the feeding wire feeding temporary stop signal is provided. .