JPS60213361A - Method for controlling wire inching - Google Patents

Abstract

PURPOSE:To improve the efficiency for positioning the end of a consumable electrode wire with an arc welding machine using said electrode wire by adjusting the closing time of a switch for commanding wire inching thereby controlling freely the feed speed of the wire. CONSTITUTION:The consumable electrode wire 25 from a reel 26 is passed through a long flexible feed path 27 by feed rolls 24 and is supplied to a welding torch 34 to generate an arc between the wire and base metals 35 for welding and to melt the wire, by which the base metals are welded. The switch 1 for commanding wire inching is closed when the wire 25 is fed in the route 27. An electric motor 21 for the feed rollers is run fast or slowly according to need by the command of an inching speed setter 2 provided with a setter VR1 during initial feeding at a constant rate and a feed speed setter VR2 after the start of continuous feeding, during said time. The wire 25 is passed fast in the route 27 and when the wire emerges from the top end of the torch 34, the wire is fed slowly, by which the feeding operation of the wire is made more efficient.

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 without being fed into the welding area, and in which these wires are manually pushed as a preparatory work before starting welding. This invention relates to a control method for inching a welding torch until the wire protrudes from the tip of the welding torch by an appropriate amount using a button switch.

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 (welding start command to start welding) is set to ensure a good arc start during actual welding.

For example, when inching, use a common setting device (the speed at which the wire is sent at a low speed from when the torch switch is pressed until the wire contacts the surface of the workpiece and an arc is generated), and when inching, set the inching command switch at this wire slowdown speed. The wire was sent toward the tip of the welding torch only while the button was pressed.

However, the feeding speed during this wire slowdown is
In order to achieve a good arc start, the speed is set to be extremely slow compared to normal welding. Therefore, such a low speed is fine when the wire has already reached the tip of the welding torch, but it becomes extremely inefficient when, for example, the wire wound on the wire reel is used up or when changing the wire. becomes. 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 by hand. I can't insert the wire into this. For this reason, the wire must be fed along a long feeding path by inching operation using the electric motor of the wire feeding drive section, and at this time, if the speed is slow as described above, it will take a long time. Of course, there is a variable resistor to set the wire slowdown speed, and it can be changed arbitrarily, but the wire slowdown speed should be set to a value that will give a good arc start, depending on the wire used and the welding current. It should be set to an appropriate value corresponding to the wire inching, and changing it each time for wire inching is not desirable as it is not only inconvenient but also causes erroneous settings. Moreover, even in the same wire inching operation, as mentioned above, there are times when the tip of the wire has already reached the tip of the welding torch and only a small amount needs to be fed, and times when the wire is sent through a long feeding path such as when replacing the wire. Therefore, 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. There is also. Furthermore, when feeding a new wire from the starting end of a long feeding path, the tip of the welding torch is monitored in both directions for a long feeding period in order to stop feeding as soon as the wire protrudes from the tip of the welding torch. There is a need. For this,
During this long feeding time, the operator is restricted to a position where the wire inching command switch can be operated. It is good if the tip of the welding torch can be seen from the feed start end, but if this is difficult (2) For example, when other equipment is installed between the feed start end and the welding torch,
This requires two people to operate the inching command switch and a person monitoring the protrusion of the wire at the welding torch, or it is necessary to devise measures such as installing the inching command switch at two locations.

Furthermore, when feeding a small amount, it is necessary to be able to accurately control the feeding amount. 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 point of arc generation is taught, so the welding line protrudes from the welding torch. Wire 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 correct teaching cannot be performed unless this feeding length is accurate. In the past, 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 troublesome work. was troublesome. 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 and the workpiece will come into strong contact with each other, and when the welding voltage is applied, this part will not be able to immediately scatter and the arc will fail to start. Become. On the other hand, if this pressing force is too small, the steel wool may become misaligned when the flux is sprayed, or the flux may enter between the steel wool and the wire, insulating them, and arc starting may 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 above-mentioned conventional devices, allows wire inching to be fed in relatively small fixed increments, thereby simplifying switch operation when feeding a small amount, and making it possible to feed large amounts of wire. When a feed amount is required, by holding down the inching command switch for more than a certain period of time, the wire will continue to be fed until the set amount is reached, and then stop, even if the command switch is no longer pressed. The wire can be set to the optimum feeding state depending on the size of the feeding amount, and one worker can easily feed the wire along a long feeding path using a single inching command switch. This paper proposes an ideal high-efficiency wire inching method.

SUMMARY OF THE INVENTION The present invention feeds a relatively small fixed amount of wire each time a wire inching command switch is closed, and when the command switch remains closed for a fixed period of time, the wire inching In addition to feeding, the wire is fed continuously after a certain period of time has elapsed, making it easy to operate whether the feeding amount is large or small, and it is also possible to maintain the continuous feeding state or increase the speed. High efficiency has been achieved by automatically stopping the feed after the required amount has been fed.

Embodiment FIG. 1 is a connection diagram of an apparatus showing an example of implementing the method of the present invention. In the figure, 1 is a wire inching command switch, which is normally provided in a remote control box, a welding operation panel, or a welding torch together with various setting devices for welding voltage on the welding side. Reference numeral 2 denotes an inching speed setting device, which includes a setting device VRI 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 which outputs a high level signal (
(hereinafter referred to as H signal).

4.5.6 is a flip-flop circuit, 4 is triggered by the fall of the input signal f of the input terminal T, and 5 and 6 are triggered by the rise of the input signal, respectively, and the output signal is inverted and becomes an H signal. Become. 7 is a timer for determining the wire feeding amount after maintaining the wire inching feeding state, and outputs an H signal for a preset time from the rise of the input signal to the input terminal T by the time setting device 7a. . 8, 9, 10 are AND gates, 11, 13 are mono multivibrators, 11 is triggered by the rising edge of the input signal, and 13 is triggered by the falling edge of the input signal, and outputs an H signal for a set time. 12°15.
16 is an inverter for signal inversion, 14 is an OR gate, 1
7a, 17b are automatic stop "on/off 1 selector switches, 18
．． 19.28.29 is an analog switch, and 20 is an amplifier, which determines the rotational speed of the wire feeding motor 21 according to an input signal. 22 is a slope control circuit;
When the slope "on/off" selection switch 23 is closed, the output changes smoothly even if the input signal of the amplifier 20 changes stepwise. This can be realized by connecting a capacitor between the outputs to provide a time delay element. 24 is a wire feeding roll driven by the electric motor 21, and the wire 25 is transferred to the wire reel 2.
The welding torch 34 and the object to be welded 35 are fed from the welding torch 34 and the workpiece 35 via the feeding path 27. 30 is a wire feed speed setting device during welding, a wire slowdown speed setting device VR3 that sets a low feeding speed until an arc is generated at the start of welding, and a wire feeding speed setting device VR3 during normal welding after an arc occurs. It consists of a speed setting device VR4, etc.

31 is a welding start command switch, which is a torch switch provided on an operation panel (not shown) or attached to the welding torch 34. 33 is a welding control circuit, and the wire 25 starts when the welding start command switch 31 is pressed.
The analog switch 28 is turned on so that the wire 25 is fed at a low speed determined by the wire slowdown speed setting device VR3 until the wire 25 comes into contact with the workpiece 35 and a current flows and generation of a welding arc is detected. In addition, after arc occurrence is detected, the analog switch 29 is controlled to conduct so that the output of the wire feed speed setting device VR5 during welding, which is faster than this, is supplied to the amplifier 20. It has a known function of supplying an output command signal determined by an output setting device to the welding power source 33.

FIGS. 2(a) to 2(i) are diagrams for explaining the operation of the embodiment of FIG. 1, (b) shows the timer 3, (C) shows the flip-flop circuit 4, and (d) shows the flip-flop circuit 5.
, (e) is the flip-flop circuit 6, (f) is the timer 7
, (g) is a mono multivibrator 10, (h
) shows the state of each output of the mono multivibrator 13, and (i) shows the state of the output of the amplifier 20. Further, the broken line in the figure shows the situation when the slope control circuit 22 is enabled.

Next, the operation of the apparatus shown in FIG. 1 will be explained with reference to FIG.

In Fig. 1, before the inching command switch 1 is pressed, the timers 3, 7, flip-flop circuits 4, 5, 6, and mono multi-byte brakes 11 and 13 are all reset, and all outputs are at a low level (hereinafter referred to as signals). ) output, analog switch 18.1
9 are both open, so the input to amplifier 20 is zero and motor 21 is stopped. Time shown in Figure 2 [
- When you press the inching command switch 1 while holding the machine, the timer 3
The input of is grounded and becomes an L signal, and the timer 3 is activated by the falling edge of this input signal and outputs an H signal for a predetermined time period r1. During this time, the output of the flip-flop circuit 4.6 remains the L signal, and therefore the inverters 12, 1
All inputs of the AND gate 10 inverted by 5.16 become H signals, and its output also becomes an H signal, and the mono multivibrator 11 is triggered by the rising edge of this H signal and outputs an H signal during the regulation time period T2. do. The analog switch 19 is rendered conductive by the H output of the mono-multivibrator 11. As a result, the amplifier 2o is supplied with the output of the setting device VR1 of the inching speed setting device 2 during fixed-length feeding, and the motor 21 is
The wire 25 is fed for a time T2 at a relatively low speed determined by the output of I. When the wire inching command switch 1 is opened before the time limit T1 of the timer 3 ends, the timer 3 is immediately reset, the AND gate 10 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 T2 of the multivibrator 11 and the set value of the speed setting device VRI is sent regardless of the length of the actual closing time. become.

Next, consider a case where the wire inching command switch 1 continues to be closed even at the end of the time period T1 of the timer 3. Time (between 2 and 14 (however, L 4 L
2 > T+) When the inching command switch 1 is closed, the flip-flop circuit 4 is triggered by the expiration of the timer 3 at time [3, and its output becomes H.
It becomes a signal. As a result, the output of the inverter 12 becomes an L signal, and the AND gate 10 is closed. On the other hand, the H signal from the flip-flop circuit 4 causes the timer 7 to output an H signal for the time T3 set by the setter 7a, which makes the analog switch 18 conductive and the wire inching speed setter 2 to the amplifier 20. The output of the setting device VR2 is supplied. As a result, the wire 25 is fed at the speed set by the setting device VR2. When the inching command switch 1 is opened after this state is reached, At~D
All inputs to the gate 8 become H signals, and as a result, the output of the flip 70 tube circuit 5 also becomes an H signal. During the time limit of the timer 7, the analog switch 18 remains conductive, and the motor 20 continues to rotate at a speed corresponding to the output of the setting device VR2. When the time limit of the timer 7 ends at time (5), its output becomes an L signal, and therefore the analog switch 18
is open. As a result, the electric It & 21 is stopped, and the falling of the output signal of the timer 7 causes the mono multivibrator 13 to output the adjustment time H signal, and this H signal causes the flip-flop circuit 4, the flip-flop circuit 5, and the timer 7 to each It will be reset and return to the initial state. In order to stop the wire inching feed within the time limit of the timer 7, it is preferable to press the wire inching command switch 1 again during the time limit T2. At time t6, when the wire inching command switch 1 is pressed, the analog switch 19 is turned on during the time limit of the timer 3 as before, and the wire 25 is fed at a speed according to the setting value of the speed setting device VRI. The multivibrator 11 stops after a time limit. After the time limit of the timer 3 ends, when the output of the flip 70 tube circuit 4 is inverted and becomes an H signal, the timer 7 starts the time limit, the analog switch 19 is opened, and the analog switch 18 is conductive, and the setting is made by the setting device VR2. Wire 25 again at the same speed.
will be sent. In this state, when the wire inching command switch 1 is once opened at time t7, the output of the flip-flop circuit 5 becomes an H signal, and it is stored that the inching command switch has been once opened. When the inching command switch 1 is closed again at time t8 within the time limit of the timer 7, both of the AND gates 9 become H signals due to this second closing, and the output of the flip-flop circuit 6 is also inverted and becomes an H signal. . This flip-flop circuit 6
The flip-flop circuits 4, 5 and timer 7 are each reset by the H signal output from the flip-flop circuits 4, 5, and the timer 7, and their output becomes an L signal, which opens the analog switch 18, which is also inverted by the inverter circuit 16, and the L signal is input to the AND gate 10. The analog switch 19 also remains open.

Therefore, the input to the amplifier 20 becomes zero, the motor 21 stops, and the wire inching ends. The flip-flop circuit 6 is reset by opening the wire innerning command switch 1 and returns to the initial state again. Here, if the set time T1 of the mono multi-vibrator 11 is set to the time required for the wire 25 to be fed on the order of several 1011, when feeding a small amount of wire, the arbitrary amount can be fed by turning the wire inching command switch 0N-OFF within this time. can do. It is preferable to set the setting device VR1 so that the feeding speed at this time is relatively low. Also, if you continue to press the inching command switch 1 until after this set time has elapsed, you will be feeding a fairly long distance by inching.
For example, by setting the time limit of the timer 7 to the time required to feed the wire by the length of the wire feeding path 27, the wire 25 can be automatically stopped when the tip of the wire 25 reaches the torch 34.

Furthermore, if the speed setting device VR2 at this time is set to a relatively high speed, work efficiency can be improved. On the other hand, when the slope selection switch 23 is turned to the ON 1 side, the slope control circuit 22 is turned on and the feeding speed is changed for a period of one month. In this case, if the output of the flip-flop circuit 4 is used as a command signal for the slope 1 person 1 - "off" selection switch, the speed change will be smoothed only when transitioning from low speed to high speed, as shown by the broken line in Fig. 2 (i). It will be possible to move to.

During welding, the inching command switch 1 is opened and the welding start command switch 31 is closed instead.
A series of operations are performed including wire feeding at a normal wire slowdown speed, arc generation, and normal welding, but since these operations are not particularly different from known methods, details will be omitted.

The present invention is not limited to the embodiment shown in FIG.
Due to the short closing of the wire inching command switch,
The wire is fed with a relatively small fixed size, and if the wire inching command switch 1 is not opened within a preset time from when it is closed, the feeding state is maintained, and this feeding amount is set in advance. It suffices if it automatically stops when a predetermined relatively large value is reached; for example, one that starts feeding at an initial speed and then gradually increases the speed, or one that automatically stops feeding when a relatively large predetermined value is reached. The speed may be changed according to a speed change program set in advance.

Furthermore, a wire inching speed setting device that outputs a single set value may be used to set the same speed during fixed-length feeding and continuous feeding, and in either case, each signal may be digitized. Of course you can get it.

Furthermore, in order to disable these continuous feeding functions when they are not required, a self-holding "ON/OFF 1 selector switch 36 is provided to disable the flip-flop circuit 6, for example, as shown by the broken line in FIG. In this case, during continuous feeding after the first constant feed, it will naturally stop when the inching command switch 1 is released.Also, if you keep pressing the wire inching command switch 1 continuously, It will automatically stop after the time set by the timer 7.

Furthermore, the setting of the wire feeding amount until automatic stop after continuous feeding is determined by the feeding time, as shown in Fig. 1, or may be determined by setting the actual feeding length. In this case, instead of the timer 7, a feed length setting device and a feed length detector, such as a multiplier for the feed speed and the feed time, or the rotation speed of the electric motor 21 or the feed roll 24 may be used. What is necessary is to provide a comparison circuit that compares both signals and finds a match.

Furthermore, instead of providing these timers and feed length detectors, a wire detector is provided at the end of the feed path 27, that is, near the welding torch 34, and when the tip of the wire reaches this position, the continuous The feeding may be automatically stopped, and safety can be further improved by combining the above-mentioned means and stopping when any set value is reached.

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 certain amount, it will feed continuously after that, and will automatically stop when it reaches this feeding amount or a preset amount, so press the wire inching command switch even when feeding a small amount. There is no need to make subtle changes to the time, making it possible to position the tip of the wire at a reasonable price, and when feeding a large amount of wire, there is no need to keep pressing the command switch, making it possible to control the straw efficiency with excellent work efficiency. .

[Brief explanation of the drawing]

9J1 is a connection diagram showing an embodiment of the apparatus for implementing the method of the present invention, and FIGS. 2(a) to 2i) are diagrams for explaining the operation of the apparatus of FIG. 1. DESCRIPTION OF SYMBOLS 1... Inching command switch, 2... Inching speed setting device, 3, 7... Timer, 4, 5.6... Flip-flop circuit, 11), 13... Mono multivibrator, 21. ...Electric motor, 25...Wire, 3
4...torch, 35...object to be welded. Representative Patent Attorney Hiroshi Nakai Procedural Amendment (Imported) May 4, 1980 1, Display of the case 1982 Patent Application No. 71629 2, Name of the invention Wire inching control method 3, Person making the amendment Related Patent Applicant: 2-1-11, Tadeyo, Yodoyo-ku, Osaka City (026) Osaka Transformer Co., Ltd. 4, Agent address: 532, 2-1-11-5 Tadeyo, Yodoyo-ku, Osaka City, Amendment Order Date of departure 9fl-

Claims (1)

[Claims] 1. In a wire inching 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, each time a wire inching command switch is closed, The wire is fed by a predetermined relatively small length, and when the command switch is closed for a certain period of time or more, the wire is fed by a predetermined relatively large feeding amount after the certain period of time has elapsed. A wire inching control method in which the wire is continuously fed until it reaches the point and then stops. 2. The wire inching 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 relatively small length. Control method. 3. During continuous feeding after the certain period of time has elapsed,
The wire inching control method according to claim 1, wherein when the -H command switch is unclosed and then closed again, the wire inching control method is stopped regardless of the set feed amount. 4. The wire inching control method according to claim 1, wherein after the predetermined time has elapsed, the feeding speed is increased at a predetermined gradient in accordance with the amount of wire fed. 5. The wire inching control method according to claim 1, wherein after the set time has elapsed, the feeding speed is changed according to a predetermined program in accordance with the wire feeding amount. 6. The wire inching control method according to claim 1, wherein the predetermined feeding amount is set in accordance with the length of the wire feeding path. 7. The wire inching control method according to claim 1, wherein the feeding amount is determined by the feeding time. 8. The wire inching control method according to claim 1, wherein the feeding amount is determined by the length of the wire actually fed. 9. The wire inching control method according to claim 1, wherein the fact that the predetermined feed amount has reached 1 is detected by wire detection means provided near the bundle end of the feed path.