JP2015112638A - Rocking type narrow groove welding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably execute automatic control of including lateral copying, in an electrode wear type narrow groove welding device.SOLUTION: A rocking type narrow groove welding device 100 comprises a torch 13 formed so that a feeding welding wire 11 obliquely projects from the tip of a tip 12, a rocking unit 10 for laterally rocking in a groove by rotating the torch 13, a lateral movement unit 20 for laterally moving the rocking unit 10 and a vertical movement unit 30 for vertically moving the rocking unit 10, and adjusts a lateral position of the torch 13 so as to reduce a difference in an arc current in a lateral stopping position by comparing an arc current in a left stopping position with an arc current in a right stoping position when rocking the torch 13 in the groove.

Description

  The present invention relates to an oscillating narrow gap welding apparatus that melts and welds a tip of a welding wire fed from a tip end while oscillating between workpieces having a narrow gap.

  Conventionally, as a device for welding workpieces arranged to face each other with a narrow groove width, a rocking type that melts and welds while rocking the tip of the welding wire fed from the tip of the tip Narrow groove welding equipment is used.

  For example, in Patent Document 1, in order to oscillate the tip of a welding core wire (welding wire), a wavy plastic deformation is applied to the welding core wire before feeding into the nozzle hole of the contact tip, and the wavy elasticity is maintained. An invention is described in which the direction of the welding core wire fed through the nozzle hole is automatically reciprocated between both the groove walls in accordance with the supply of the core wire and the progress of welding. .

  Further, Patent Document 2 discloses that the welding core wire (welding wire) is subjected to wavy plastic deformation to be swung and the left and right copying (adjustment of the left and right positions) between the groove walls is performed. An invention is described in which an integral value in each cycle of the arc current waveform is obtained and control is performed so that the difference between the integral values becomes small.

  Similarly, as a method for performing left-right copying, Patent Document 3 discloses a swing of an arc formed at the tip of a welding core wire and a swinging means for causing a wavy plastic deformation in the welding core. An invention is described in which a phase difference is calculated to determine the current oscillation position of the arc, and the deviation position from the center is determined and controlled by associating the obtained oscillation position with the value of the welding current or welding voltage. .

  On the other hand, as a groove tracking control method in non-consumable electrode arc welding, Patent Document 4 discloses an arc voltage at the time when the left-right oscillation is stopped in the groove and performs groove tracking control based on a difference between the left and right arc voltages. The invention has been described.

Japanese Patent Laid-Open No. 52-110246 JP-A-5-146877 JP 2004-268088 A JP 2002-45966 A

  However, in the case of the invention described in Patent Document 1, it is not possible to make a left-right copy between the two walls of the groove. In the case of the inventions described in Patent Document 2 and Patent Document 3, control based on the values of the melting current and the melting voltage is performed in order to perform the left-right copying between the groove walls. There is a problem that the current is not stable. That is, in the case of a device that applies wavy plastic deformation to a welding core wire (welding wire) and swings, the welding wire 51 moves within the power feed tip 52 as shown in FIG. There are things that do not.

  On the other hand, the invention described in Patent Document 4 relates to a groove tracking control method in non-consumable electrode arc welding, and melts and welds the tip of a welding wire fed from the tip end in the groove. It cannot be applied to an electrode wear type narrow gap welding apparatus.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and is configured to stably perform automatic control including left-right copying in an electrode consumption type narrow gap welding apparatus.

  In order to solve the above-mentioned problems, the swing type narrow gap welding apparatus of the present invention includes a torch formed so that a welding wire to be fed projects obliquely from a tip end of the tip, and a groove by rotating the torch. An oscillating narrow gap welding apparatus having an oscillating unit that oscillates left and right, a left and right moving unit that moves the oscillating unit left and right, and an up and down moving unit that moves the oscillating unit up and down. And comparing the arc current at the left stop position with the arc current at the right stop position when the torch is swung in the groove, so that the difference between the arc currents at the left and right stop positions is reduced. The left and right positions of the torch are adjusted.

  Further preferably, the adjustment of the left-right position of the torch is performed by at least one of a change of a swing range of the torch by the swing unit and a movement of the swing unit in the left-right direction by the left-right moving unit. .

  Preferably, the measurement of the arc current at the left and right stop positions is performed without changing the vertical position of the torch in the groove.

  Preferably, the vertical position of the torch is adjusted so that the average value of the arc current when the torch is swung in the groove approaches a predetermined value.

  Preferably, the adjustment of the left-right position of the torch and the up-and-down movement of the torch during the swing from the left-right one stop position to the other stop position immediately after measurement of the arc current at the left-right stop position The position adjustment is performed simultaneously.

  The swing type narrow groove welding apparatus of the present invention includes a torch formed so that a welding wire to be fed protrudes obliquely from the tip end, and a swing that rotates the torch left and right within the groove. Since the moving unit is provided, by rotating the torch by the swing unit, it is possible to swing left and right within the groove while changing the direction of the obliquely protruding welding wire. In addition, the swing range can be changed by adjusting the left and right rotation angles.

  Moreover, since the left / right moving unit for moving the swing unit to the left / right is provided, the left / right position of the torch in the groove can be adjusted by the left / right moving unit.

  Moreover, since the vertical movement unit for moving the swing unit up and down is provided, the vertical position of the torch in the groove can be adjusted by the vertical movement unit.

  In addition, the arc current at the left stop position and the arc current at the right stop position when the torch is swung in the groove are compared, and the difference between the arc currents at the left and right stop positions is reduced. The left / right position can be adjusted. At this time, the welding wire is not subjected to wave-like plastic deformation, and the welding wire always contacts at one point without moving within the power feed tip, so that the arc current can be stably and stably controlled. .

  The left and right position of the torch can be adjusted by changing the swing range of the torch by the swing unit, or by moving the swing unit in the left and right direction by the left and right moving unit. You can also Therefore, finer and more accurate control can be performed.

  In addition, by measuring the arc current at the left and right stop positions without changing the vertical position of the torch in the groove, even if the accuracy of the material to be welded is low, the horizontal position of the torch is offset. The right and left positions can be adjusted with accurate determination.

  Also, by adjusting the vertical position of the torch so that the average value of the arc current when the torch is swung in the groove approaches a predetermined value, the protruding amount of the welding wire is made constant. It is possible to perform up-and-down copying.

  In addition, the adjustment of the left / right position of the torch and the vertical position of the torch are simultaneously performed during the swing from the left / right stop position to the other stop position immediately after the measurement of the arc current at the left / right stop positions. By doing so, left-right copying and vertical copying can be performed in a short time, and more stable welding can be performed.

  As described above, according to the present invention, automatic control including left-right tracing can be stably performed in an electrode-consumable narrow gap welding apparatus.

It is a block diagram of the rocking | fluctuation type narrow gap welding apparatus which concerns on embodiment of this invention. It is an enlarged view which shows the front-end | tip of the electric power feeding chip | tip which concerns on embodiment of this invention. It is a figure which shows the front-end | tip angle and rocking | fluctuation range of the electric power feeding chip | tip which concerns on embodiment of this invention. It is explanatory drawing which shows the example of the acquisition timing of the data at the time of right-and-left copying. It is explanatory drawing which shows the example of the acquisition timing of the data at the time of up-down copying. It is an enlarged view which shows the front-end | tip of the electric power feeding chip | tip which concerns on a prior art example. It is an enlarged view which shows the front-end | tip of the electric power feeding chip which concerns on other embodiment.

  Next, with reference to FIG. 1 thru | or FIG. 5, the rocking | fluctuation type narrow groove welding apparatus which concerns on embodiment of this invention is demonstrated. First, with reference to FIG. 1, the whole structure of the rocking | fluctuation type narrow gap welding apparatus 100 which concerns on this embodiment is demonstrated.

  An oscillating narrow gap welding apparatus 100 according to the present embodiment is mainly composed of a welding power source 1, a control apparatus 2, a relay box 3, and a welding head 4, and welds the inside of the narrow gap of the material 5 to be welded. It is like that. Further, the welding head 4 includes a swing unit 10 that rotates the torch in the groove to swing left and right, a left-right moving unit 20 that moves the swing unit 10 left and right, and a swing unit 10 that moves up and down. A vertical movement unit 30 is provided.

  The welding power source 1 supplies electric power for melting the welding wire and also supplies electric power for driving the swing unit 10, the left / right moving unit 20, and the up / down moving unit 30. The control device 2 controls the power supply from the welding power source 1 and measures an arc current at a predetermined position in the groove by a built-in program, and the relay box 3 based on the measured current value. The oscillating unit 10, the left / right moving unit 20 and the up / down moving unit 30 are controlled via these to change the position of the torch in the groove.

  Next, the front end portion of the power feed tip according to the embodiment of the present invention will be described. FIG. 2 is an enlarged view showing the power supply chip 12 according to the present embodiment. The tip of the power feed tip 12 attached to the torch 13 is bent obliquely. The welding wire 11 fed through the inside of the torch 13 changes its direction along the bending of the power feed tip 12 and protrudes obliquely from the tip of the power feed tip 12. That is, the welding wire 11 goes out from the angled hole while bending at the tip of the power feed tip 12. Thus, the torch 13 is formed so that the welding wire 11 to be fed protrudes obliquely from the tip of the power feed tip 12. When the torch 13 is rotated, the direction of the tip of the power feed tip 12 changes so as to draw a circle and swings. Accordingly, the protruding direction of the welding wire 11 changes. The welding wire 11 is not subjected to wave-like plastic deformation, and is always in contact at one point without moving within the power feed tip.

  Next, the tip angle (bending angle) and the swing range of the power feed tip 12 will be described. FIG. 3 is a diagram showing a tip angle and a swing range of the power feed tip 12 according to the embodiment of the present invention. The tip angle of the power feed tip 12 can be set variously. The lower row in FIG. 3 shows an example of the tip end angle, which is set to (a) 15 degrees, (b) 25 degrees, (c) 35 degrees, and (d) 45 degrees, respectively. 3 shows the swing range of the torch when the welding wire protrusion length is assumed to be 10 mm and the arc length is 10 mm at each tip end angle, and the torch is moved within the groove. Seen from above.

  When the tip tip angle shown in FIG. 3A is 15 degrees, the tip tip allowable angle is 90 degrees on one side, the wire tip allowable angle is 53 degrees on one side, and the arc tip allowable angle is 34 degrees on one side. When the tip end angle shown in FIG. 3B is 25 degrees, the tip tip allowable angle is 57 degrees on one side, the wire tip allowable angle is 29 degrees on one side, and the arc tip allowable angle is 20 degrees on one side. When the tip end angle shown in FIG. 3C is 35 degrees, the tip end allowable angle is 38 degrees on one side, the wire end allowable angle is 21 degrees on one side, and the arc tip allowable angle is 14 degrees on one side. When the tip end angle shown in FIG. 3D is 45 degrees, the tip tip allowable angle is 30 degrees on one side, the wire tip allowable angle is 17 degrees on one side, and the arc tip allowable angle is 12 degrees on one side. Thus, as the tip end angle increases, the allowable angle within the groove decreases.

  Next, arc current measurement (data acquisition) and scanning control in the groove will be described. The control method shown below is an example, and the swing angle of the torch, the time setting, the data acquisition timing, etc. are not limited to this.

(Left / right copy)
First, left-right copying (left-right position adjustment) will be described. FIG. 4 is an explanatory diagram illustrating an example of data acquisition timing during left-right copying. In the drawing, the “left” and “right” straight lines indicate the left and right groove walls, and the torch swings to the left and right within the left and right straight lines (within both walls of the groove). And the state (1) → (2) →... → (11) → (12) → (1) → (2) →. The swing angle of the torch is 34 degrees on one side, and the left and right stop time is 0.4 seconds.

  As setting parameters for data acquisition, [1] the data acquisition start angle is 33 degrees, [2] the data acquisition delay time is 0.01 seconds, and [3] the data acquisition time is 0.2 seconds. It should be noted that “data acquisition start angle” ≦ “torch swing angle” and “data acquisition delay time” + “data acquisition time” ≦ “left / right stop time”. Each parameter can be set independently on the left and right.

1. Data is acquired during periods (2) to (3) and (5) to (6), and a copying operation is performed during periods (7) to (12).
2. Data acquisition on the left side of the swing end: [2] After the data acquisition delay time elapses from the time when the swing angle exceeds the [1] data acquisition start angle, the period data set in [3] data acquisition time is acquired.
3. In this example, data is acquired for 0.2 seconds after 0.01 seconds from the time when the swing angle exceeds 33 degrees.
4). Data acquisition on the right side of the swing end: After the swing angle exceeds the [1] data acquisition start angle, after the [2] data acquisition delay time elapses, the period data set in [3] data acquisition time is acquired.
5. In this example, data is acquired for 0.2 seconds after 0.01 seconds have elapsed from the time when the swing angle exceeds −33 degrees.

  As described above, the arc current in the groove is measured (data acquisition), and the arc current at the left stop position is compared with the arc current at the right stop position, so that the difference between the arc currents at the left and right stop positions is reduced. As described above, the left and right positions of the torch 13 are adjusted.

  The adjustment of the left / right position of the torch 13 can be performed by at least one of changing the swing range of the torch 13 by the swing unit 10 and moving the swing unit 10 in the left / right direction by the left / right moving unit 20. Therefore, it can be performed by changing the swing range of the torch 13 by the swing unit 10, or by moving the swing unit 10 in the left-right direction by the left / right moving unit 20, or by both. When the change is made only by changing the swing range of the torch 13, the amount of rotation of the left and right of the torch 13 may be changed.

  Moreover, it is preferable to measure the arc current (data acquisition) at the left and right stop positions without changing the vertical position of the torch in the groove. Thereby, even if it is a case where the precision of a to-be-welded material is low, the deviation of the left-right position of a torch can be determined exactly.

(Up-and-down copying)
Next, vertical scanning (adjustment of the vertical position) will be described. FIG. 5 is an explanatory diagram illustrating an example of data acquisition timing during vertical scanning. In the drawing, the “left” and “right” straight lines indicate the left and right groove walls, and the torch swings to the left and right within the left and right straight lines (within both walls of the groove). And the state (1) → (2) →... → (11) → (12) → (1) → (2) →. The swing angle of the torch is 34 degrees on one side, and the left and right stop time is 0.4 seconds.

  As setting parameters for data acquisition, [1] the rocking end non-acquisition angle is 1 degree, [2] the rocking end non-acquisition time is 0.2 seconds, and [3] the average number of data is 8. It should be noted that “swing end unacquired angle” ≦ “torch swing angle”.

1. Data is acquired during the periods (3) to (5) and (9) to (11) and the periods (6) to (8) and (12) to (2). Follow the period.
2. Swing end non-acquisition period: Data is not acquired until the “unacquired time” elapses from the time when the swing angle reaches the angle obtained by subtracting the “unacquired angle” from the “torch swing angle”.
3. In the case of this example, the data is obtained from the point when the swing angle reaches 33 degrees obtained by subtracting 1 degree from the "torch swing angle" from 34 degrees until the "unacquired time" reaches 0.2 seconds. Do not get.
4). Except for the data non-acquisition time, data is always taken and is set as a moving average (in this example, the moving average number is 8). The moving average value is compared with a preset ACC current value.
5. The hold state is set when data is not yet acquired, and the operation is resumed after the acquisition is started.

  As described above, the arc current in the groove is measured (data acquisition), and the vertical position of the torch 13 is adjusted so that the average value of the arc current approaches a predetermined value.

  The vertical position of the torch 13 is adjusted by the vertical movement of the swing unit 10 by the vertical movement unit 30.

  Note that the left-right position adjustment and the vertical position adjustment may be performed simultaneously. For example, immediately after the measurement of the arc current at the left and right stop positions, the torch 13 swings from the left and right stop positions to the other stop position ("between the left stop position and the right stop position" or "right stop position"). → Between the left stop position)), the left and right position adjustment and the vertical position adjustment can be performed simultaneously.

  The swing-type narrow groove welding apparatus 100 according to this embodiment includes a torch 13 formed so that a welding wire 11 to be fed protrudes obliquely from a tip end 12, and a torch 13 is rotated to rotate the inside of the groove. Since the torch 13 is rotated by the oscillating unit 10, the oscillating unit 10 oscillates left and right within the groove while changing the direction of the obliquely protruding welding wire 11. Can be made. In addition, the swing range can be changed by adjusting the left and right rotation angles.

  Further, since the left / right moving unit 20 for moving the swing unit 10 to the left / right is provided, the left / right position of the torch 13 in the groove can be adjusted by the left / right moving unit 20.

  Further, since the vertical movement unit 30 for moving the swing unit 10 up and down is provided, the vertical position of the torch 13 in the groove can be adjusted by the vertical movement unit 30.

  Further, the arc current at the left stop position and the arc current at the right stop position when the torch 13 is swung in the groove are compared, and the difference between the arc currents at the left and right stop positions is reduced. 13 left and right positions can be adjusted. At this time, the welding wire 11 is not subjected to wave-like plastic deformation, and the welding wire 11 always contacts at one point without moving in the power feed tip 12, so that the arc current is stably and stably controlled. be able to.

  The left / right position of the torch 13 can be adjusted by changing the swing range of the torch 13 by the swing unit 10 or by moving the swing unit 10 in the left / right direction by the left / right moving unit 20. However, both can be performed. Therefore, finer and more accurate control can be performed.

  Further, by measuring the arc current at the left and right stop positions without changing the vertical position of the torch 13 in the groove, even if the accuracy of the material to be welded 5 is low, the left and right positions of the torch 13 It is possible to adjust the left and right positions by accurately determining the bias.

  Further, by adjusting the vertical position of the torch 13 so that the average value of the arc current when the torch 13 is swung in the groove approaches a predetermined value, the protruding amount of the welding wire 11 is constant. Thus, it is possible to perform vertical scanning.

  In addition, immediately after the measurement of the arc current at the left and right stop positions, the adjustment of the left and right positions of the torch 13 and the vertical position of the torch 13 during the swing from the left and right stop positions of the torch 13 to the other stop position. Are performed at the same time, the left and right copying and the vertical copying can be performed in a short time, and more stable welding can be performed.

  As described above, according to the swing-type narrow groove welding apparatus 100 according to the present embodiment, automatic control including right and left copying can be stably performed in the electrode wear-type narrow groove welding apparatus.

  In addition, this invention is not limited to the said embodiment, A various change is possible. For example, not only the adjustment of the left / right position of the torch 13 in the groove, but also the swinging itself may be performed by combining the swinging unit 10 and the left / right moving unit 20. At this time, the torch 13 may be moved left and right while rotating, or the torch 13 may be rotated after moving the torch 13 left and right.

  Further, when the left and right arc currents change greatly compared to a predetermined value, it can be determined that the power supply tip is consumed and can be used as a guide for tip replacement. That is, when the tip of the power supply tip is consumed, the diameter of the hole through which the welding wire passes is enlarged so that the wire protrusion angle changes rapidly, and this utilizes the phenomenon that the left and right arc currents exhibit abnormal values. be able to.

  In addition, when the workpiece is arranged only on one side, the position of the torch can be adjusted by comparing the arc current with a predetermined value instead of the method of comparing the left and right arc currents.

  In the present embodiment, the tip of the power feed tip 12 attached to the torch 13 is formed to be bent obliquely so that the welding wire 11 to be fed protrudes obliquely from the tip of the tip 12. 7 may be formed like a power supply chip 62 according to another embodiment shown in FIG. The tip of the power feed tip 62 is not bent obliquely, but the internal hole 63 through which the welding wire passes is bent in the diagonal direction. Thereby, the welding wire protrudes at an angle of 15 degrees with respect to the rotation axis of the torch (note that the angle of 15 degrees shown in FIG. 7 is an example and is not limited to this. ). Even with a configuration such as the power feed tip 62, the welding wire to be fed can be projected obliquely from the tip end, and by rotating the torch, the direction of the obliquely projected welding wire is changed in the groove. It can be swung left and right.

DESCRIPTION OF SYMBOLS 1 Welding power supply 2 Control apparatus 3 Relay box 4 Welding head 5 To-be-welded material 10 Oscillating unit 11 Welding wire 12 Feeding tip 13 Torch 20 Left and right moving unit 30 Vertical moving unit 51 Welding wire 52 Feeding tip 62 Feeding tip 63 Hole 100 Oscillating Type narrow groove welding equipment

Claims (5)

A torch formed so that the welding wire to be fed protrudes obliquely from the tip end, a swing unit that rotates the torch to swing left and right within the groove, and moves the swing unit to the left and right A swing type narrow gap welding apparatus having a left and right moving unit and a vertical moving unit for moving the swing unit up and down,
Comparing the arc current at the left stop position and the arc current at the right stop position when the torch is swung in the groove, the difference between the arc currents at the left and right stop positions is reduced. A swing-type narrow groove welding apparatus characterized by adjusting left and right positions.   The adjustment of the left-right position of the torch is performed by at least one of changing a swing range of the torch by the swing unit and moving the swing unit in the left-right direction by the left-right moving unit. The swing type narrow gap welding apparatus as described.   The swing type narrow groove welding apparatus according to claim 1 or 2, wherein the arc current is measured at the left and right stop positions without changing the vertical position of the torch in the groove.   4. The swing type according to claim 3, wherein the vertical position of the torch is adjusted so that an average value of arc current when the torch is swung in a groove approaches a predetermined value. 5. Narrow groove welding equipment.   Immediately after the measurement of the arc current at the left and right stop positions, during the swing from the left and right stop positions of the torch to the other stop position, adjustment of the left and right positions of the torch and adjustment of the vertical position of the torch The swing-type narrow groove welding apparatus according to claim 4, wherein: