JPS60206575A - Method for controlling wire inching - Google Patents

Abstract

PURPOSE:To inch easily, accurately and efficiently a wire with good reproducibility by feeding the wire at the fixed size at every closing of an inching command switch and feeding continuously the wire when the closed circuit continues for the specified time or above. CONSTITUTION:The wire 20 is inched by closing the inching command switch 1 and driving an electric motor, which is controlled in accordance with the output set value of a welding speed setter 25, by the output set value of an inching speed setter 2 in the stage of inching the wire of an arc welding machine which drives the motor 16 to feed the wire at a specified speed to a welding torch 29 and welds materials 30 to be welded. The wire is fed at the fixed size at every closing of the switch at the fixed size feed speed to be set by the above-mentioned setter 2 when the switch is closed for a short period. The wire 20 is kept continuously supplied at the continuous feed speed and the high speed according to need after the switch 1 is closed and is once released until the switch is closed again during the lapse of the time when the switch is closed for a prescribed period or above.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to arc welding in which consumable electrode wires or filler wires are welded while being fed into the welding area, and as a preparatory work before the start of welding, these wires are connected to a manual pushbutton. Feed 1 when using a switch to perform inching feed (wire inching) until the appropriate amount protrudes from the tip of the welding torch
2 is related to the control method.

In conventional automatic or semi-automatic arc welding, the speed of wire feeding during welding is determined in accordance with the welding current, welding voltage, etc., and the wire is fed automatically. However, when newly feeding the wire from the coiled wire reel to the tip of the welding torch, or when the tip of the wire has already reached the welding torch, the defective part of the tip shape is removed or the wire feeding status is checked. For example, there may be cases where it is desired to feed a desired amount of wire separately from welding.

In response to such a request, a wire inching command switch is normally provided separately, and the operator presses the switch appropriately to feed the wire in increments to perform the above-mentioned operations. Conventionally, during this inching feed, the wire slowdown speed is set to ensure a good arc start during actual welding. When inching, the wire is moved to the tip of the welding torch only while the inching command switch is pressed at this wire slowdown speed. It was supposed to be sent towards the destination.

However, the feeding speed when the wire was down was
In order to achieve a good arc start, the speed is set to be extremely slow compared to normal welding. Is such a low speed acceptable when the wire has already reached the tip of the welding torch, or is it extremely inefficient, for example when the wire wound on a wire reel is used up or when changing the wire? It becomes work. In other words, there is a long path of several meters to tens of meters between the drive unit for feeding the wire and the welding torch, and this path is usually structured to pass through a flexible conduit, so it cannot be done manually. The wire cannot be inserted into it.1. For this reason, it is necessary to feed the wire over a long feeding path by an inching operation using the electric motor of the wire feeding drive section, and at this time, even if the speed is slow (N speed) as described above, a long Gf time is required. There is a variable resistor to set the slowdown speed, and it can be changed arbitrarily.This wire slowdown speed is originally a value that corresponds to the wire and welding current used for good arc starting. This is also undesirable.Moreover, even in the same wire inching operation, as mentioned above, if the tip of the wire has already reached the tip of the welding torch and it is fed out just a little, There are times when it is good and times when sending a long feeding path, such as when replacing wires.
If the high speed is set when a small amount is to be sent, and the inching command switch is pressed continuously, it will not only be difficult to adjust the feed amount, but also dangerous for the operator.

Furthermore, when delivering small amounts, it is necessary to be able to accurately control the amount delivered. For example, in a teaching playback type arc welding robot, it is necessary to accurately teach the welding line to the robot before welding, but at this time, the wire protruding from the welding torch is used to teach the arc generation point. Tip position (
(position relative to the welding torch) must always be fixed. For this purpose, the wire must be fed in advance by an inching operation, but unless this feeding length is accurate, correct teaching cannot be performed. Conventionally, feeding and stopping were simply determined by a push button switch, so there was no other way than to protrude extra and cut it with pliers at an appropriate position, which resulted in poor accuracy and The work was tedious.

Furthermore, in submerged arc welding, arc starting is usually performed by sandwiching a small lump of steel wool between the tip of the wire and the object to be welded, but in order to do this, the steel wool must be pressed lightly with the wire. If this pressing force is too strong, the thick wire or the object to be welded will come into strong contact, resulting in failure. On the other hand, if this pressing force is too small, the steel wool may become misaligned when the flux is sprayed, or the slack may enter between the steel wool and the wire, insulating them, and the arc start will fail as well. I will do it. Therefore, in any of these cases, the conventional method of adjusting the wire tip, which must be accurately positioned, by the time the inching command switch is pressed is to slow down the inching speed sufficiently and adjust the timing of releasing the switch to the wire feeding device. It was necessary to learn from experience, taking into account the amount of coasting, and required skill.

OBJECTS OF THE INVENTION The present invention eliminates the drawbacks of the conventional device described above, feeds the wire in increments by a fixed amount, simplifies the switch operation when feeding a small amount, and makes it possible to feed a large amount. When a large amount of feed is required, by holding down the inching command switch for more than a certain period of time, the inching command switch can be changed to continuous feeding, and when the feed amount is small, accurate and reproducible feeding can be performed without any skill required. This paper proposes a wire inching control method that allows efficient feeding even when the feeding amount is large.

SUMMARY OF THE INVENTION The present invention feeds a fixed amount of wire each time a wire inching command switch is closed. In addition to this, the wire is continuously fed after a certain period of time has elapsed, making the operation easy regardless of whether the feeding amount is large or small.Furthermore, the continuous feeding state can be maintained or the speed can be increased. This achieved high efficiency.

Embodiment FIG. 1 is a connection diagram of an apparatus illustrating an example of implementing the method of the present invention. In the figure, 1 is a wire inching command switch, which is usually provided in a remote control box, a welding operation panel, or a welding torch together with setting devices for welding current and welding voltage. Reference numeral 2 denotes an inching speed setting device, which includes a setting device VR1 at the time of initial fixed-size feeding and a feeding speed setting device VR2 after the start of continuous feeding. 3
is a timer and is a high level signal for a preset time from the falling edge of the input signal to the input terminal T (it turns into an H signal). 7, 8, 9 are AND gates, and 10 is a high level signal for a preset time from the fall of the input signal to the input terminal T. A multivibrator that outputs an H signal for a set time from the rising edge, 11, 12.13 are inverters for signal inversion, 14.15 and 24.25 are analog switches,
Reference numeral 16 denotes an amplifier, which determines the rotational speed of the wire feeding electric motor 17 according to an input signal. Reference numeral 18 denotes a slope control circuit, which smoothly changes the output even if the input signal of the amplifier 16 changes stepwise when the slope 1/1'1/1/1 selector switch 19 is closed. As this slope control circuit 18, for example, the amplifier 1
This can be realized by connecting a capacitor between the input and output of 6 to provide a time delay element. 20 is a wire feeding roll driven by the electric motor 17, and the wire 21
is fed from the wire reel 22 through the feeding path 23 toward the welding torch 30 and the workpiece 31. 26 is a wire feed speed setting device during bath welding, a wire slowdown speed setting device V R3 that sets a low feeding speed until an arc occurs at the start of welding, and a wire slowdown speed setting device V R3 for setting a low feeding speed until an arc occurs at the start of welding. It consists of a feeding speed setting device VR4, etc. 27 is a welding start command switch, which is a torch switch provided on an operation panel (not shown) or attached to the welding torch 30. 28 is a welding control circuit, which slows down the wire 21 from when the welding start command switch 27 is pressed until the wire 21 contacts the workpiece 31 and current flows and generation of a welding arc is detected. The analog switch 24 is made conductive so as to feed at a low speed determined by the speed setting device VR3, and the output of the wire feeding speed setting device VR5 during welding, which is higher than this after arc occurrence is detected, is sent to the amplifier 16. It has a known function of controlling the analog switch 25 to conduct so as to supply the welding power source 29 with an output command signal determined by an output setting device (not shown).

In Fig. 1, before the inching command switch 1 is pressed, the timer 3 and the flip-flop circuits 4, 5, and 6 are all reset, and each output is a low level (hereinafter referred to as a low signal) output. Switches 14,15 are both open and therefore amplifier 1
6 is zero, and the electric motor 17 is stopped. When the inner command switch 1 is pressed in this state, the human power of the timer 3 is grounded and becomes an L signal, and the fall of this input signal activates the timer 3 and outputs an H signal for a fixed time period T1. During this time, the output of the flip-flop circuit 4.6 is L.
remains the signal, and therefore the inverters 11, 12.1
All inputs of the A I"J D gate 9 inverted by 3 become H signals, and its output also becomes an H signal, and the mono multivibrator 10 is triggered by the rising edge of this H signal and outputs an H signal for a fixed time period T2. The analog switch 15 is made conductive by the H output of the mono multivibrator 10. As a result, the output of the setting device VR1 of the inching speed setting device 2 at the time of fixed-length feeding is supplied to the amplifier 16. , the electric motor 17 is set by this setting device VR.
The wire 21 is fed at a relatively low speed determined by the output of 1 for a time T2. If the wire inching command switch 1 is opened before the end of the time limit T of the timer 3, the timer 3 is immediately reset, and the ANiJNi top 9 is opened and everything returns to its initial state.

Therefore, when the closing time of the wire inching command switch 1 is short, a fixed amount of wire determined by the set time 1'2 of the multivibrator 10 and the set value of the speed setting device VR1 is sent regardless of the length of the actual closing time. It will be done.

Consider the case where the wire inching command switch 1 continues to be closed even at the end of the time period 'l'1 of the -4 timer 3. When the timer 3 expires, the flip-flop circuit 4 is triggered and its output becomes an H signal.

As a result, the output of the inverter 11 becomes an L signal and the AND gate 9 is closed. On the other hand, the analog switch 13 is made conductive by the H signal of the flip-flop circuit 4, and the output of the setting device VR2 of the wire inching speed setting device 2 is supplied to the amplifier 15. As a result, the wire 20 is fed at the speed set by the setting device VR21. When the inching command switch 1 is opened in this state, the AND gate 7
Both inputs become H signals, and as a result, the output of the flip-flop circuit 5 also becomes an H signal, and it is stored that the inching command switch has been opened once. At this time, since the output of the flip-flop circuit 4 remains the H signal, the analog switch 13 remains conductive, and the motor 16 continues to rotate at a speed corresponding to the output of the setting device VR2. To stop wire inching, press the wire inching command switch 1 again. Due to this second closing, both inputs of the ANI gate 8 become H signals, and the output of the flip-flop circuit 6 is also inverted and becomes an H signal. By the H signal output of this flip-flop circuit 6, the flip-flop circuit 4
and 5 are reset, and their output becomes an L signal, which opens the analog switch 14, which is inverted by the inverter circuit 12, and the L signal is input to the AND gate 9, so that the mono multivibrator 10 does not output again. do not have. Therefore, the input to the amplifier 16 becomes zero, the motor 17 stops, and the wire inching ends. The flip-flop circuit 6 is reset by opening the wire inching switch 1 and returns to its initial state.

In the embodiment shown in the figure, the wire 2 is controlled by closing the wire inching command switch for a short time.
1 can be repeated for each closed circuit, and if the inching command switch is held down until the time set by timer 3 has elapsed, the wire will be continuously fed after the time set by timer 3 has elapsed. Ru. Moreover, after this continuous feeding is achieved, the feeding state is maintained even if the inching command switch 1 is opened, and the feeding state is not canceled until the switch 1 is closed again. It's convenient. Also, in this case, the speed setting device V
If R2 is set to a value that provides a relatively high speed, work efficiency can be further improved.

On the other hand, 7 people pressed the slope "ON 6 - OFF" selection switch 19.
When set to the side, the slope control circuit 18 becomes effective, and the feeding speed changes smoothly.

In this case, if the output of the flip-flop circuit 4 is used as a command signal for the slope "on 1.-I+off 1 selection switch, the speed change can be smoothly shifted over a period of months only at the start of continuous feeding.

FIGS. 2(a) to 2g) are diagrams for explaining the operation of the embodiment shown in FIG. 1 over time, and FIG. , (b) is timer 3, (C) is flip-flop circuit 4, (d) is flip-flop circuit 5, (e)
Hough 1J tube flop circuit 6, (f) shows the state of each output of the mono multivibrator 10, and g) shows the state of the output of the amplifier 16. Further, the broken line in the figure shows the situation when the slope control circuit 18 is enabled.

During welding, the inching command switch 1 is opened and the welding start command switch 27 is closed instead.
Wire feeding with normal wire slowdown speed,
A series of operations are performed including occurrence of cracking and normal welding, but since these operations are not particularly different from known methods, details will be omitted.

Furthermore, the present invention is not limited to the method implemented by the embodiment shown in FIG. If the switch is not released within a certain period of time, it is sufficient that the feeder stops, and if the switch is not released within a certain period of time, then the feeder switches to a continuous feeding state. It's okay. This can be achieved by removing the AND gate 7.8, the flip-flop circuits 5, 6 and the winter inverter 3 in the embodiment of FIG. Furthermore, by providing a self-holding single "-'tJJ" switch 32 shown by a broken line in FIG. 1 and connecting it so as to bypass the flip-flop circuit 6, it is possible to select to maintain the continuous feeding state only when necessary. . Furthermore, it is also possible to adopt a system in which the feeding speed after the start of continuous feeding is gradually increased according to the feeding amount, or to program these speed changes in advance so that they become appropriate values. Of course, it is also possible to use a wire inching speed setter that outputs a single setting value and to feed the wire according to the common speed setting value both during fixed-length feeding and during continuous feeding.

Effects of the Invention As described above, the present invention provides that when the wire inching command switch is closed for a short time, the wire is fed by a fixed amount regardless of the closing time, and when the command switch is continuously closed for a fixed period of time or more, the wire is sent by a certain amount. In addition to feeding a fixed amount, the wire is fed continuously after that, so even when feeding a small amount, there is no need to delicately change the time to press the wire inching command switch, and accurate positioning of the wire tip is possible. Furthermore, when feeding a large amount of wire, the feeding amount can be determined by pressing the command switch as in the past, making it possible to achieve highly efficient control with excellent workability.

[Brief explanation of the drawing]

FIG. 1 is a connection diagram showing an embodiment of the apparatus for implementing the method of the present invention, and FIGS. 2(a) to 2(g) are diagrams for explaining the operation of the apparatus of FIG. 1. . l... Inching command switch, 2... Inching speed setting device, 3... Timer, 4, 5.6... Flip-flop circuit, 10... Mono multivibrator,
17... Electric motor, 21... Wire, 30... Torch, 31... Welding object. Agent: Hiroshi Nakai, Hiroshi Nakai, Procedural Neyama Masashi (self-motivated), April 27, 1980, Display of Case 18, 1982 Patent Application No. 64608 2, Title of Invention: Wire Inching Control Method 3, Person Who Amends Case Relationship with Patent Applicant: 2-1-11 Tabyo, Yodoyo-ku, Osaka (026) Osaka Transformer Co., Ltd. 4, Agent [Contact Information Telephone (06) 301-1212] 5, Date of Amendment Order Voluntary

Claims (1)

[Scope of Claims] 1. In a wire inching command control method for an arc welding machine that performs welding while feeding a consumable electrode wire or filler wire to a welding part at a predetermined speed, the wire inching command switch is closed. A wire inching e control method in which the wire is fed by a predetermined length every time, and when the command switch is closed for a certain period of time or more, the wire is continuously fed after the certain period of time has elapsed. . 2. The wire inching tube according to claim 1, wherein the speed at which the wire is continuously fed after the certain period of time has elapsed is higher than the speed at which the wire is fed by the predetermined length. Control method. 3. After the certain period of time has elapsed, the state of continuously feeding the wire is maintained until the command switch is once unclosed and then closed again. The wire/wire according to any of paragraph 2
Cink 11 control method. 4. Wire inching according to claim 1 or 3, in which the 111111 vernal feeding speed is increased at a predetermined gradient when the wire is continuously fed after the certain period of time has elapsed. - Control method. 5. Continuous wire feeding after the elapse of a certain period of time, especially the wire inching according to claim 1 or 3, in which the feeding speed is changed according to a predetermined program. How to do it.