JPS58110181A - Hot wire tig welding machine - Google Patents

Abstract

PURPOSE:To obtain good bead shapes with good reproducibility by making automatic setting and controlling to correct arc current value and feed speed of a wire possible by setting the thickness of base materials and a welding speed. CONSTITUTION:When the thickness of a base material and a welding speed are set with a setter 36, arc current is set with a function generating circuit 38, and is converted to the signal corresponding to the feed speed of a wire with a function generating circuit 40. The set value and the detected arc current are compared in a comparator 42, and on and off of a switching element is controlled The converted output of the circuit 40 is applied to a motor 60 for driving of a wire, and is inputted together with the output of a current detector 48 for heating of the wire to a comparator 52, by which an on and off of the switching element 56 is controlled. By the above-mentioned operations, heating current is run to a wire 16 so as to melt the same just on the surface of base material 26 in conformity with the feed speed. The necessary arc current from which the current for heating of the wire is deducted is supplied by the on-off operations of the element 46.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hot wire T'IG welding machine, and particularly to a hot wire T'IG welding machine that performs welding while also supplying current to a filler wire to preheat the wire.

In the hot wire T-type G welding machine, as shown in Figure 1,
The electric power source 14 maintains the arc 22 between the tungsten electrode 12 of the wire (10) and the base material 26, and the drive row 218 feeds the filler wire 16 to the base material 26. At this time, the wire 16 becomes the base material 26! As soon as the wire 16 is touched, the power supply 20 and the power supply 28
A current flows inside the wire, thereby preheating the shear wire 16IIi, reaching the base material 26, almost melting at a good point, and depositing it as a bead 24. The arrow in the figure indicates the direction of welding progress.

By the way, this type of conventional welding machine is configured such that the arc current value and wire feeding speed must be adjusted individually with respect to the plate thickness of the base material 26 and the welding speed. Therefore, if the wire feeding speed is too fast for a certain arc current value, the wire 14i
As the current flowing into KfIL- increases, the new welding speed of 24 becomes a convex speed with a slight overlap, as shown in TG 2 (a).On the other hand, if the wire feeding speed is too slow, This results in an undercut bead as shown in FIG. 2 (1)). Furthermore, if the welding speed is slow, the amount of heat input to the base metal 26 is too large, and the base metal may not melt. Because of this, the conventional I! ! It is very difficult to adjust the arc current value and wire feeding speed to appropriate values in the welding machine, and this requires a high degree of skill.

This release! AFi was created in view of the problems of the conventional methods mentioned above, and by setting the plate thickness and welding speed of the target material and base material, the appropriate arc current value and wire feeding speed are automatically set. An object of the present invention is to provide a hot wire T-type G welding machine which can be set to have a good bead shape with good reproducibility and has no overlap during welding.

In order to achieve the above object, the present invention includes a setting means for setting the plate thickness of the base material and the welding speed, and control target values for arc current and filler wire feeding mode based on the setting state of the setting means. calculation means for calculating each of
The present invention is characterized by comprising control means for controlling the arc current and the feeding speed of the filler wire, respectively, based on the calculation results of the calculation means.

Hereinafter, a preferred embodiment of the present invention will be described based on Figure WJK.

Figure 3 shows an embodiment of the hot wire TIG welding machine according to the present invention. In the conventional welding machine shown in the figure, the arc current detector 32, the setting device 36, the first . The second function generating circuit 38°40, the first . It includes a second comparison circuit 42.52, a wire heating current detector 48, a switching element 46.56 using a transistor or the like, a reactor 62.64, a diode 66.68, and the like. Other details of the configuration are almost the same as those of the conventional welding machine described above. Further, the Mxm second function generating circuits 38 and 40 correspond to the arithmetic means, and are constructed using a ROM or the like that stores an arithmetic table.

Here, the principle of this invention will be explained. First, when the thickness of the base material 26 and the arc current are kept constant, the appearance of the bead 24 changes depending on the welding speed and wire supercharging speed. Here, the base material 26 is made of annealed copper with a plate thickness of IJm,
Good wire diameter 1.2■φ.

Arc length 3.2 When the welding speed is 1000/min, the wire feeding speed and wire heating current are adjusted so that the wire 16 comes into contact with the base metal 26 in a nearly molten state, and the arc current is The shape of the bead for each combination of wire feeding speed and wire feeding speed is experimentally determined, and the range in which a stable bead without melt drop or overlap can be obtained is shown in 6 diagrams. It becomes like this. Also,!
#'i (B) in Figure @4 is also a region where the arc current is large, and the heat input to the base metal 26 is too large, resulting in melt drop. The areas (C) and (M) in Figure 4 are also areas where the arc current is small and the wire feeding speed is high, so the bead 24 and the base metal 26 do not fit well, resulting in overlap. , and Fig. 4 shows that the welding speed is 70
Also shown is the condition range in which a stable bead can be obtained in the case of 0 .mu./min-1500 ms+/min. According to this, the welding speed is 1
At 500 m, if the wire feeding speed is slow, undercuts or humping beads will occur and good welding results cannot be obtained. From the above, given the plate thickness and welding speed, the appropriate combination of arc current and wire feed speed can be determined.

The thick straight IIi in the upper right corner shown in Figure 4! Nine suitable conditions for lFi, arc current and wire feed speed are sequentially combined. If this is rewritten as a relationship between welding speed and arc current, and between welding speed and wire feeding speed, the result will be as shown in FIG. Above 1st. Second function generation circuit 38.4
0 defines the functional relationship as shown in Figure 5.

Next, the operation of the welding machine shown in the rs diagram will be explained.

First, the plate thickness and welding speed are set using the setting device 36.

The setting state of the f# contact speed 1lFi is converted into a signal proportional to the arc voltage #IK by the first function generating circuit 38, and becomes one input of the first comparison circuit 42. On the other hand, the arc current is detected by the detector 32, and its detection output is amplified by the amplifier 34 and becomes the other input of the comparison circuit 42 of @1. The output of the first comparator circuit 42 is amplified by an amplifier 44 to control the switching element 4 on and off. Further, it is converted to be proportional to the wire feeding speed by the function generating circuit 40 of the plate thickness setting shape 11t[2.

The converted output is applied to a wire drive motor 60 via an amplifier 58. Further, the converted output serves as one input of the second comparison circuit 52. The output of the wire heating R detector 48 is applied to the other input of the two comparison circuits 52 via an amplifier 50. The comparison circuit @2 controls the switching element 56 on and off via the output amplifier 54 of 52. The arc current and wire heating current are each supplied from a power source 30.

Through the above-described operation, a heating current is applied to the wire 16 in accordance with the wire feeding speed so that the wire 16 becomes molten on the surface of the base material 26. Also,
The required arc current, excluding the wire heating current, is supplied by the on-off operation of the switching element 46. Immediately after the switching element 41518 is turned off, the energy stored in the reactors 62 and 64 circulates through the diodes 66 and 68.

As described above, hot wire TIG welding using Q9Q is performed by setting the plate thickness of the base material to be welded and the welding speed, and adjusting the arc current value and feed of the filler wire according to the settings. Since the feed rate is automatically set to meet the optimum conditions for bead formation, it is possible to obtain a bead without welding defects such as melt drop or overlapping with a simple operation.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a conventional hot wire T-type G welding machine, FIG. 2 is a diagram showing a bead shape, and FIG. 3 is a diagram showing an embodiment of a hot wire T-type G welding machine according to the present invention. , FIG. 4 is a diagram showing the appropriate range of arc current value and wire feeding speed, and FIG. 5 is a diagram showing the combination of welding speed, arc current, and wire feeding speed. Identical members in the figures are designated by the same reference numerals; 10 is a torch; 12 is a torch;
Fi tungsten electrode, 16 filler wire, 22 arc, 26 base material, 30 power supply, 32 arc current detector, 36 #i setting device, 38° 40 function generation circuit, -
42, 52d comparison circuit, 48 wire heating current detector,
46 and 56 are switch/Ill elements, and 60 is a wire feeding drive motor. Agent Patent Attorney Makoto Kuzuno - (Name) Figure 1 Figure 2 Figure 4 Figure 71 Fuyuki Onna [A] Figure 5 Movement L71 [m%] Procedural Amendment (Voluntary) Mr. Commissioner of the Japan Patent Office 1. Indication of the case: Japanese Patent Application No. 56-215682 2. Title of the invention: Hot wire TIG welding machine 3. Name of the person making the amendment: (6699) Patent attorney Shin Kuzuno
-5, Detailed explanation of the invention column 6 of the specification subject to amendment, Contents of amendment (1) [The setting state of the welding speed is the first function generating circuit 38 "is converted into a signal proportional to the arc current," is corrected to "the arc current is set in the first function generating circuit 38 from the settings of the plate thickness and welding speed." (2) Page 6 of the specification, lines 18 to 20 [Also,
The setting state of the plate thickness is converted by the second function generating circuit 40 so as to be proportional to the wire feeding speed. '' should be corrected to ``At the same time, the settings of the plate pressure and welding speed are converted into a signal corresponding to the wire feeding speed in the second function generating circuit 40.'' Below

Claims (1)

[Claims] +1) Setting means for setting the plate thickness of the base material and welding speed, calculation means for calculating respective control target values of arc current and filler wire feeding speed based on the setting state of this setting means, and this calculation means. and control means for respectively controlling the arc current and the feeding speed of the filler wire based on the calculation results of the means) '7 (-?T Engineering G #**.