JP6155151B2 - Wire feeding device - Google Patents

Description

  The present invention relates to a wire feeding device for feeding a welding wire.

  Conventionally, a welding wire is mechanically short-circuited by periodically advancing (inching) and retreating (retracting) the welding wire with respect to a base material to realize welding with less spatter. For example, Patent Document 1 describes that stable welding can be realized by periodically driving a drive source to realize high-speed advancement and retreat of a welding wire. Moreover, in the wire feeding for moving the welding wire forward and backward, Patent Document 2 discloses that there is a gap between a wire feeding device for feeding the welding wire and a wire feeding device for moving the welding wire forward and backward. It is described that a welding wire buffer is installed and the welding wire is fed using feedback of the buffer. By providing such a buffer, the welding wire can be prevented from slipping, and appropriate wire feeding can be realized.

JP 2012-91222 A JP 2004-50292 A

However, when a buffer is provided, it is necessary to perform calibration. By performing the calibration, it is possible to appropriately know how much welding wire is accommodated in the buffer. As a result, it is possible to prevent the welding wire from buckling or the like due to buffering of the welding wire exceeding the specified value, or to prevent the welding wire from having an insufficient buffer amount.
Normally, such calibration is performed manually, and thus there is a problem that time and labor are required for the calibration. In particular, when a wire feeding device without a buffer amount storage mechanism is used, there is a problem that such calibration time and labor are required at each startup.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a wire feeding device that can reduce time and labor required for calibration related to the buffer amount of a welding wire.

In order to achieve the above object, in a wire feeding device according to the present invention, a first wire feeding unit for feeding a welding wire and a welding wire fed by the first wire feeding unit are buffered. A wire buffer, a second wire feeding unit that feeds the welding wire buffered by the wire buffer to the welding torch, and a buffer amount that obtains a buffer amount that is the amount of the welding wire buffered by the wire buffer An acquisition unit; an acquisition unit that acquires a force in the length direction of the welding wire buffered by the wire buffer; and a calibration unit that calibrates the buffer amount acquisition unit. The welding wire is moved so as to reduce the buffer amount by at least one of the two wire feeding units, and the tension obtained by the obtaining unit exceeds the first threshold value. The buffer amount is set to the minimum value, the welding wire is moved so that the buffer amount increases by at least one of the first and second wire feeding units, and the pressing force acquired by the acquiring unit is the second threshold value. The buffer amount at the time when the value exceeds the maximum value is set.
With such a configuration, the buffer amount acquisition unit can be automatically calibrated, and the time and labor required for calibration can be reduced. Further, even a wire feeding device without a buffer amount storage mechanism can be automatically calibrated when the device is activated.

In the wire feeding device according to the present invention, the welding by at least one of the first and second wire feeding units is performed so that the buffer amount acquired by the buffer amount acquiring unit is between the maximum value and the minimum value. You may further provide the controller which controls feeding of a wire.
With such a configuration, it is possible to realize appropriate control using an accurate buffer amount in feeding the welding wire.

Further, in the wire feeding device according to the present invention, the wire buffer has an inlet and an outlet of the welding wire, and a case that accommodates a welding wire whose length from the inlet to the outlet changes, and a welding in the case. A wire guide through which the wire passes, and a shaft support portion that pivotally supports at least a part of the wire guide with respect to the case, and the buffer amount acquisition unit is a wire guide that is supported by the shaft support portion. You may acquire the buffer amount according to an angle.
With such a configuration, it is possible to acquire a buffer amount corresponding to the angle of the wire guide.

  According to the wire feeding device of the present invention, it becomes possible to automatically perform calibration related to the acquisition of the buffer amount, and it is possible to reduce time and labor for the calibration.

The block diagram which shows the structure of the wire feeding apparatus by Embodiment 1 of this invention. The figure which shows an example of a structure of the wire buffer by the embodiment The figure which shows an example of a structure of the wire buffer by the embodiment The flowchart which shows operation | movement of the wire feeder by the same embodiment

  Hereinafter, a wire feeding device according to the present invention will be described using embodiments. In the following embodiments, components and steps denoted by the same reference numerals are the same or equivalent, and repetitive description may be omitted.

A wire feeding device according to an embodiment of the present invention will be described with reference to the drawings. The wire feeding device according to the present embodiment automatically calibrates the buffer amount acquisition unit.
FIG. 1 is a block diagram showing a configuration of a wire feeding device 1 according to the present embodiment. The wire feeding device 1 according to the present embodiment includes a first wire feeding unit 11, a wire buffer 12, a second wire feeding unit 13, a buffer amount obtaining unit 14, an obtaining unit 15, and a calibration. The unit 16 and the controller 17 are provided.

  The first wire feeding unit 11 feeds the welding wire 5 wound around the wire reel 2 toward the welding torch 3. The first wire feeding unit 11 normally feeds the welding wire 5 in the forward direction, but may be moved in the direction of retracting the welding wire 5 during calibration. The advance of the welding wire 5 is a direction in which the welding wire 5 advances toward the welding torch 3, and the retreat of the welding wire 5 is a direction in which the welding wire 5 advances toward the wire reel 2. The first wire feeding unit 11 has a mechanism for feeding the welding wire 5. The mechanism is already known and will not be described in detail. The mechanism may include, for example, a roller that advances or retracts the welding wire 5 and a motor that rotates the roller. For example, the motor may rotate in a direction in which the welding wire 5 is advanced or retracted in accordance with an instruction from the calibration unit 16 or the controller 17.

  The wire buffer 12 exists between the first wire feeding unit 11 and the second wire feeding unit 13. In the wire buffer 12, the welding wire 5 fed by the first wire feeding unit 11 is buffered. When the length of the welding wire 5 accommodated in the wire buffer 12 changes, the buffer amount of the welding wire 5 changes. When the amount of the welding wire 5 fed in the forward direction by the first wire feeding unit 11 is larger than the amount of the welding wire 5 fed in the forward direction by the second wire feeding unit 13 The buffer amount will increase, and if it is small, the buffer amount will decrease. An example of the configuration of the wire buffer 12 will be described later.

  The second wire feeding unit 13 feeds the welding wire 5 buffered by the wire buffer 12 to the welding torch 3. In the welding torch 3, arc welding is performed by a voltage applied from a welding power source. For example, the second wire feeding unit 13 may feed the welding wire 5 while repeatedly moving the welding wire 5 forward and backward relative to the base material. The forward and backward repetitions may be performed periodically, for example, or may be performed by feedback. In the former case, the second wire feeding unit 13 may repeatedly advance and retract the welding wire 5 by repeating a predetermined cycle, for example. In the latter case, for example, when a short circuit is detected when the welding wire 5 advances, the second wire feeding unit 13 retracts the welding wire 5 and short-circuits the advancement and retraction of the welding wire 5. It may be repeated according to the detection. The feeding mechanism of the welding wire 5 included in the second wire feeding unit 13 is also the same as that of the first wire feeding unit 11, and the description thereof is omitted. However, when the second wire feeding unit 13 repeats the advance and retreat of the welding wire 5 at a high speed, it is preferable to use a motor capable of realizing the high-speed advance and retreat.

  The buffer amount acquisition unit 14 acquires a buffer amount that is the amount of the welding wire 5 buffered by the wire buffer 12. Since the method for acquiring the buffer amount differs depending on the configuration of the wire buffer 12, it will be described later together with the description of the configuration of the wire buffer 12.

  The acquisition unit 15 acquires a force in the length direction of the welding wire 5 buffered by the wire buffer 12. In addition, the force in the length direction of the welding wire 5 acquired by the acquisition unit 15 is obtained when the buffer amount is calibrated. The force in the length direction becomes tension when the welding wire 5 is pulled, and becomes pressing force when the welding wire 5 is compressed in the length direction (when pressed). The pressing force is a force applied in the direction opposite to the tension. That is, the force according to the tensile stress becomes the tension, and the force according to the compressive stress becomes the pressing force. The force in the length direction is not a strict value because it is used to know whether the amount of the welding wire 5 buffered by the wire buffer 12 has become the minimum value or the maximum value. Also good. In other words, the acquisition unit 15 may acquire a force that allows the user to know that the force in the length direction has become larger than when the buffer amount is between the minimum value and the maximum value. . When the motor feeds the welding wire 5 at a low speed, there is a correlation between the torque of the motor and the force in the length direction of the welding wire 5. Therefore, the acquisition unit 15 may acquire the force in the length direction of the welding wire 5 according to the current value of the motor used for feeding the welding wire 5. The motor is a motor of the first wire feeding unit 11 and / or the second wire feeding unit 13 that feeds the welding wire 5. The force in the length direction of the welding wire 5 may be, for example, a value obtained by converting a current value into a force in the length direction, or may be a current value itself. In the latter case, the current value is regarded as a force in the length direction. Note that the absolute value of the current value may be used as the current value. Moreover, the acquisition part 15 may acquire the tension | tensile_strength and pushing force of the welding wire 5 using the force of the welding wire 5 regarding the direction orthogonal to a length direction. The acquisition of the tension and the pressing force may be performed using, for example, a mechanism similar to the tension sensor. Specifically, the tension can be measured according to the force with which the welding wire 5 tries to become a straight line, and the pressing force can be measured according to the force with which the welding wire 5 tries to bend. In addition, since the friction in the lengthwise direction of the welding wire 5 is acquired in this way, a new friction related to the feeding of the welding wire 5 is generated. Therefore, the acquisition is performed only at the time of calibration, It is preferable that it is not performed at the time of other normal feeding. In the present embodiment, a case will be mainly described in which the acquisition unit 15 acquires a tension and a pressing force that are current values of a feeding motor of the second wire feeding unit 13.

  The calibration unit 16 calibrates the buffer amount acquisition unit 14. The calibration of the buffer amount acquisition unit 14 means (1) setting of a minimum value and (2) setting of a maximum value of the buffer amount acquired by the buffer amount acquisition unit 14. Each will be described below.

(1) Setting of minimum value of buffer amount The calibration unit 16 has a buffer amount of the welding wire 5 buffered by the wire buffer 12 by at least one of the first and second wire feeding units 11 and 13. The welding wire 5 is moved so as to decrease. Specifically, the calibration unit 16 may move the welding wire 5 backward by the first wire feeding unit 11, may advance the welding wire 5 by the second wire feeding unit 13, or The welding wire 5 may be moved backward and forward by both the first and second wire feeding units 11 and 13. When moving the welding wire 5 to one feeding part, the movement of the welding wire 5 by the other feeding part is stopped. Note that while the welding wire 5 is being moved, the calibration unit 16 compares the tension of the welding wire 5 acquired by the acquisition unit 15 with the first threshold value. When the amount of the welding wire 5 buffered by the wire buffer 12 is minimized, the welding wire 5 cannot be pulled out any further, and the tension of the welding wire 5 is increased. Therefore, when the tension acquired by the acquisition unit 15 exceeds the first threshold, the calibration unit 16 stops the movement of the welding wire 5, and the buffer amount acquisition unit 14 minimizes the buffer amount at that time. Set to value. In this way, the minimum buffer amount can be automatically set.

(2) Setting of Maximum Buffer Amount The calibration unit 16 has a buffer amount of the welding wire 5 buffered by the wire buffer 12 by at least one of the first and second wire feeding units 11 and 13. The welding wire 5 is moved so as to increase. Specifically, the calibration unit 16 may advance the welding wire 5 by the first wire feeding unit 11, may retract the welding wire 5 by the second wire feeding unit 13, or The welding wire 5 may be moved forward and backward by both the first and second wire feeding units 11 and 13, respectively. When moving the welding wire 5 to one feeding part, the movement of the welding wire 5 by the other feeding part is stopped. Note that while the welding wire 5 is being moved, the calibration unit 16 compares the pressing force of the welding wire 5 acquired by the acquisition unit 15 with the second threshold value. When the amount of the welding wire 5 buffered by the wire buffer 12 is the largest, a force is required to push the welding wire 5 in and the pressing force of the welding wire 5 is increased. Therefore, when the pressing force acquired by the acquisition unit 15 exceeds the second threshold value, the calibration unit 16 stops the movement of the welding wire 5 and the buffer amount acquisition unit 14 sets the buffer amount at that time. Set to the maximum value. In this way, the maximum buffer amount can be automatically set.

  Here, the first threshold value and the second threshold value may be the same value or different values. In addition, in the case of the minimum value of the buffer amount, the tension becomes considerably large because the welding wire 5 is fully extended. On the other hand, in the case of the maximum value of the buffer amount, the resistance for inserting the welding wire 5 into the wire buffer 12 is high, and the pressing force does not increase so much. Therefore, the first threshold value may be set to a value larger than the second threshold value.

  Note that this calibration is performed when the minimum value and the maximum value of the buffer amount are not set in the buffer amount acquisition unit 14 (for example, when the wire feeder 1 starts to be used or when the wire feeder without a storage mechanism is activated). May be performed at other times, and may be performed at other times. In the latter case, for example, calibration may be performed at regular intervals.

  In addition, the minimum value and the maximum value of the buffer amount acquired by the buffer amount acquisition unit 14 are set to the minimum value of the value measured to acquire the buffer amount (this value may be referred to as “sensor value”). The maximum value may be stored in a recording medium (not shown). The accumulation may be performed by, for example, the buffer amount acquisition unit 14 or the calibration unit 16. In this case, for example, the minimum value S1 and the maximum value S2 of the sensor values are accumulated according to the calibration, and the control using the minimum value S1, the maximum value S2, and the current sensor value is performed by the controller 17. Will be done by. The setting of the minimum value and the maximum value of the buffer amount acquired by the buffer amount acquisition unit 14 associates the minimum value and the maximum value of the sensor value with the minimum value and the maximum value of the buffer amount that are a predetermined range. Thus, information such as a conversion formula or conversion table for converting the sensor value and the buffer amount may be set. The setting may be performed by the buffer amount acquisition unit 14 or the calibration unit 16, for example. In this case, for example, the range of S1 to S2 is set so that the minimum value S1 and maximum value S2 of the acquired sensor values correspond to the predetermined minimum value B1 and maximum value B2 of the buffer amount. An expression, a table (corresponding information) or the like for converting the sensor value into a buffer amount in the range of B1 to B2 may be generated and stored in a recording medium (not shown). In this case, the buffer amount acquisition unit 14 may convert the sensor value into a buffer amount and output it. Further, the controller 17 may perform feeding control of the welding wire 5 using the converted buffer amount. The relationship between the sensor value in the range of S1 to S2 and the buffer amount in the range of B1 to B2 may or may not be linear. If the relationship between the two is not linear, information indicating the relationship between the two is stored in advance on a recording medium (not shown), and the calibration unit 16 may generate information for conversion between the two using the information. Good.

  In addition, the buffer amount acquisition unit 14 or the calibration unit 16 may set an optimum amount of the buffer amount that is between the maximum value and the minimum value of the buffer amount. The optimum amount of the buffer amount may be, for example, the exact middle point between the maximum value and the minimum value of the buffer amount, and the maximum value and the minimum value of the buffer amount are divided at a predetermined ratio ( Value).

  The controller 17 uses the welding wire 5 by at least one of the first and second wire feeding units 11 and 13 so that the buffer amount acquired by the buffer amount acquiring unit 14 is between the maximum value and the minimum value. Control the feeding of For example, the controller 17 may control at least one of the first and second wire feeding units 11 and 13 so that the buffer amount becomes the above-described optimum amount. The method of this control is not limited, but an example will be briefly described. For example, when the first wire feeding unit 11 feeds the welding wire 5 at a predetermined feeding speed, the controller 17 sets the second wire so that the buffer amount is constant. The feeding of the welding wire 5 by the feeding unit 13 may be controlled. By doing so, a predetermined amount of the welding wire 5 can be consumed, and the possibility of welding defects and the like can be reduced. In the case of the control, since the buffer amount is required to be constant, fine control is required. For example, when the second wire feeding unit 13 feeds the welding wire 5 in accordance with the speed command of the welding wire 5, the controller 17 prevents the buffer amount from becoming the minimum value. The feeding of the welding wire 5 by the first wire feeding unit 11 may be controlled. In the case of such control, fine control is not required because the amount of buffered welding wire 5 need only be between a minimum value and a maximum value.

FIG. 2A is a diagram illustrating an example of the wire buffer 12. In FIG. 2A, the wire buffer 12 includes a case 21, a wire guide 22, and a shaft support portion 23.
The case 21 has an inlet 21 a and an outlet 21 b for the welding wire 5. The case 21 accommodates the welding wire 5 whose length from the inlet 21a to the outlet 21b changes. That is, buffering is performed by changing the accommodation length of the welding wire 5. The buffer amount increases as the accommodation length increases, and the buffer amount decreases as the accommodation length decreases.

  The wire guide 22 is a guide through which the welding wire 5 passes in the case 21. The wire guide 22 may pass only a part of the welding wire 5 accommodated in the case 21, or may pass all of the welding wire 5 accommodated in the case 21. Also good. FIG. 2A shows the latter case. That is, the wire guide 22 exists from the inlet 21a to the outlet 21b. Note that the wire guide 22 may be, for example, a metal wire formed in a coil shape or a coil-shaped resin. The wire guide 22 expands and contracts in length according to the amount of the welding wire 5 accommodated in the case 21.

  The shaft support portion 23 rotatably supports at least a part of the wire guide 22 with respect to the case 21. In the case of FIG. 2A, the shaft support portion 23 supports the substantially center of the wire guide 22 so as to be rotatable in the arrow direction at the approximately center of the case 21. In addition, the shaft support part 23 may be a disk-shaped member provided so as to be rotatable with respect to the case 21, for example. Further, the wire guide 22 may pass through a hole provided in the diameter direction of the shaft support portion 23.

  In the wire buffer 12 shown in FIG. 2A, when the buffer amount of the welding wire 5 becomes the minimum value, the curvature of the wire guide 22 is reduced to the position 22a. On the other hand, as the buffer amount of the welding wire 5 increases, the curvature of the wire guide 22 increases, and the shaft support portion 23 rotates in response thereto, for example, the wire guide 22 is positioned at 22b. Thus, since the buffer amount of the welding wire 5 and the angle of the wire guide 22 in the shaft support portion 23 are in a monotonic mapping relationship, the buffer amount acquisition unit 14 is supported by the wire guide 22 supported by the shaft support portion 23. The buffer amount corresponding to the angle may be acquired. In that case, the buffer amount acquisition unit 14 may acquire the buffer amount by acquiring the angle of the shaft support unit 23. The buffer amount may be the angle itself, or may be an angle converted into a buffer amount. The angle may be acquired by, for example, an encoder that measures the angle of the shaft support 23, may be acquired by a laser angle meter that measures the angle of a predetermined portion of the shaft support 23, or other angle sensor. Or the like. The encoder may be, for example, an incremental type or an absolute type. In the former case, a separate storage mechanism for storing the current angle may or may not be provided. If the storage mechanism is not provided, for example, calibration may be performed every time the apparatus is activated. When the angle corresponding to the minimum value of the buffer amount set by the calibration unit 16 is A and the angle corresponding to the maximum value is B, the controller 17 causes the angle of the shaft support 23 to be larger than A, The buffer amount may be controlled to be less than B.

  FIG. 2B is a diagram illustrating another example of the wire buffer 12. In FIG. 2B, the wire buffer 12 includes a case 21 and a wire guide 25. Note that only a part of the welding wire 5 accommodated in the case 21 passes through the wire guide 25. Therefore, unlike the wire guide 22, the wire guide 25 may not expand or contract. That is, it may be tubular rather than coiled. Moreover, the wire guide 25 shall be provided so that the movement of the range of the arrow in FIG. 2B is possible. The wire guide 25 moves upward in the figure when the buffer amount increases, and moves downward in the figure when the buffer amount decreases. Therefore, the buffer amount acquisition unit 14 can acquire the buffer amount by acquiring the position of the wire guide 25 in the arrow direction. The buffer amount may be the position itself, or may be a value obtained by converting the position into a buffer amount.

  It goes without saying that the method for obtaining the buffer amount is not limited to the above-described one. For example, the buffer amount acquisition unit 14 includes a roller that is provided at each of the inlet 21a and the outlet 21b of the case 21 and that rotates according to the movement of the welding wire 5, and an encoder that detects the number of rotations of the roller. It may be. By using the roller and the encoder, the buffer amount acquisition unit 14 can acquire the length of the welding wire 5 that has entered the case 21 and the length of the welding wire 5 that has exited the case 21. Therefore, the buffer amount acquisition unit 14 may acquire the buffer amount by subtracting the length of the welding wire 5 exiting from the case 21 from the length of the welding wire 5 entering the case 21.

Next, operation | movement of the wire feeder 1 is demonstrated using the flowchart of FIG. The flowchart of FIG. 3 is a flowchart showing a calibration process by the calibration unit 16 or the like.
(Step S101) The calibration unit 16 passes an instruction to reduce the buffer amount to at least one of the first and second wire feeding units 11 and 13. In response to the instruction, the welding wire 5 is pulled out from the wire buffer 12, and the buffer amount decreases. In addition, it is suitable for the motor driven at that time to move the welding wire 5 at a low speed.

  (Step S102) The calibration unit 16 determines whether or not the tension acquired by the acquisition unit 15 is greater than the first threshold value. If the tension is greater than the first threshold, the process proceeds to step S103. If not, the process of step S102 is repeated until the tension is greater than the first threshold.

  (Step S103) The calibration unit 16 gives an instruction to stop the movement to at least one of the first and second wire feeding units 11 and 13 that are moving the welding wire 5. In response to the instruction, the movement of the welding wire 5 is stopped.

  (Step S <b> 104) The calibration unit 16 passes an instruction to set the buffer amount at that time to the minimum value to the buffer amount acquisition unit 14. In response to the instruction, the buffer amount acquisition unit 14 sets the angle of the shaft support 23 at that time, the position of the wire guide 25, the value of the encoder, or the like to the minimum value of the buffer amount.

  (Step S105) The calibration unit 16 passes an instruction for increasing the buffer amount to at least one of the first and second wire feeding units 11 and 13. In response to the instruction, the welding wire 5 is drawn into the wire buffer 12, and the buffer amount increases. In addition, it is suitable for the motor driven at that time to move the welding wire 5 at a low speed.

  (Step S106) The calibration unit 16 determines whether or not the pressing force acquired by the acquisition unit 15 is greater than the second threshold value. If the pressing force is larger than the second threshold value, the process proceeds to step S107. If not, the process of step S106 is repeated until the pressing force becomes larger than the second threshold value.

  (Step S107) The calibration unit 16 gives an instruction to stop the movement to at least one of the first and second wire feeding units 11 and 13 that are moving the welding wire 5. In response to the instruction, the movement of the welding wire 5 is stopped.

  (Step S <b> 108) The calibration unit 16 passes an instruction to set the buffer amount at that time to the maximum value to the buffer amount acquisition unit 14. In response to the instruction, the buffer amount acquisition unit 14 sets the angle of the shaft support 23 at that time, the position of the wire guide 25, the value of the encoder, or the like to the maximum value of the buffer amount.

(Step S109) The buffer amount acquisition unit 14 sets an amount corresponding to a point (for example, a middle point) that internally divides between the maximum value and the minimum value of the buffer amount at a predetermined ratio as an optimal amount. . Then, a series of calibration processes is completed.
Although not shown in the flowchart of FIG. 3, the feeding control of the welding wire 5 by the controller 17 may be performed in accordance with the subsequent welding. At that time, for example, the controller 17 may use the maximum value and the minimum value of the buffer amount accumulated by the buffer amount acquisition unit 14.

  Next, operation | movement of the wire feeder 1 by this Embodiment is demonstrated using a specific example. In this specific example, the buffer amount is calibrated by moving the welding wire 5 to the second wire feeding unit 13. Moreover, the wire buffer 12 is what is shown by FIG. 2A, and the buffer amount acquisition part 14 shall acquire the angle of the axial support part 23 using an encoder.

  When the wire feeder 1 is used for the first time, the operator pulls the welding wire 5 drawn from the wire reel 2 into the first wire feeder 11, the wire buffer 12, the second wire feeder 13, and the welding. It is assumed that the torch 3 is passed in the order. Then, it is assumed that the operator gives an instruction to start calibration to the wire feeder 1. Then, in response to the instruction, the calibration unit 16 gives an instruction to advance the welding wire 5 to the second wire feeding unit 13 in order to reduce the buffer amount. And according to the instruction | indication, the 2nd wire supply part 13 advances the welding wire 5 (step S101). Note that the current value of the motor used for the forward movement is acquired by the acquisition unit 15, and the tension according to the current value is passed to the calibration unit 16. The tension may be an absolute value of a current value, for example. And the calibration part 16 judges whether the tension | tensile_strength became larger than the 1st threshold value (step S102). When the tension exceeds the first threshold according to the movement of the welding wire 5 by the second wire feeding unit 13, the calibration unit 16 stops the movement of the welding wire 5 by the second wire feeding unit 13. (Step S103). In addition, the calibration unit 16 passes an instruction to the buffer amount acquisition unit 14 to set a minimum value. In response to the instruction, the buffer amount acquisition unit 14 sets the encoder value at that time to the minimum value of the buffer amount (step S104). If the encoder value at that time is 10 °, the buffer amount acquisition unit 14 sets 10 ° to the minimum value.

  Next, the calibration unit 16 causes the second wire feeding unit 13 to retract the welding wire 5 and determines whether the pressing force is greater than the second threshold (steps S105 and S106). The pressing force may be, for example, an absolute value of a current value of a motor used for retracting the welding wire 5. When the pressing force exceeds the second threshold value, the calibration unit 16 stops the movement of the welding wire 5 by the second wire feeding unit 13 and sets the encoder value at that time to the maximum buffer amount. (Steps S107 and S108). If the encoder value at that time is 70 °, the buffer amount acquisition unit 14 sets 70 ° to the maximum value. Further, assuming that the relationship between the angle of the wire guide 22 acquired by the encoder and the length of the welding wire 5 to be buffered is linear, the calibration unit 16 calculates the maximum value and the minimum value accumulated by the buffer amount acquisition unit 14. The value 40 ° of the center encoder with respect to the value is set to 0 point of the buffer amount. If the maximum buffer amount is “10” and the minimum buffer amount is “−10”, the calibration unit 16 sets the buffer amount Y to Y = (X−40) / 3. Set. X is a value of the encoder. When the calibration is completed in this way, the buffer amount acquisition unit 14 calculates the buffer amount Y corresponding to the value X of the encoder using the equation, and passes the buffer amount to the controller 17. Then, the controller 17 uses the buffer amount Y received from the buffer amount acquisition unit 14 to control the feeding of the welding wire 5 so that the buffer amount of the welding wire 5 falls within the range of −10 to 10. Will do.

  As described above, according to the wire feeding device 1 according to the present embodiment, it is possible to automatically perform calibration relating to the buffer amount. Therefore, it is possible to reduce the time and labor required when the calibration is performed manually. In addition, since calibration can be automatically performed when the apparatus is activated, convenience is improved particularly in the wire feeding apparatus 1 that does not have a buffer amount storage mechanism. Further, since the calibration can be automatically performed, the buffer amount acquisition unit 14 may not include a buffer amount storage mechanism, and the cost can be reduced by using such a buffer amount acquisition unit 14. Can do. Further, when the acquisition unit 15 acquires a tension or the like corresponding to the current value, it may be possible to add a mechanism for calibration without newly adding a physical configuration. Further, even the buffer amount acquisition unit 14 in which a steady error occurs as time passes can be periodically calibrated, so that an accurate buffer amount can be acquired, and as a result, accurate feedback is obtained. Control becomes possible. Moreover, even if the ideal origin position differs depending on the configuration and state of the welding system, it can be flexibly handled.

  In the present embodiment, the case where the wire feeding device 1 includes the controller 17 and performs control related to the feeding of the wire has been described, but this need not be the case. The control related to the feeding of the wire may be performed by another device. In that case, the wire feeder 1 outputs the buffer amount, receives a control instruction corresponding to the buffer amount, and the first and second wire feeders 11 and 13 operate according to the control instruction. Also good.

  Further, as described above, it goes without saying that the configurations of the wire buffer 12 and the buffer amount acquisition unit 14 are not limited to those described above. A wire buffer 12 or a buffer amount acquisition unit 14 having a configuration other than those described above may be used.

  In the above embodiment, each process or each function may be realized by centralized processing by a single device or a single system, or may be distributedly processed by a plurality of devices or a plurality of systems. It may be realized by doing.

  In the above embodiment, the information exchange between the components is performed by one component when, for example, the two components that exchange the information are physically different from each other. It may be performed by outputting information and receiving information by the other component, or when two components that exchange information are physically the same, one component May be performed by moving from the phase of the process corresponding to to the phase of the process corresponding to the other component.

  In the above embodiment, information related to processing executed by each component, for example, information received, acquired, selected, generated, transmitted, or received by each component In addition, information such as threshold values, mathematical formulas, setting values, and the like used in processing by each component may be temporarily or for a long time held in a recording medium (not shown), even if not specified in the above description. . Further, the storage of information in the recording medium (not shown) may be performed by each component or a storage unit (not shown). Further, reading of information from the recording medium (not shown) may be performed by each component or a reading unit (not shown).

  Further, in the above embodiment, when the information used by each component etc., for example, information such as threshold values and various set values used by each component may be changed by the user, the above explanation is given. Even if not explicitly stated, the user may be able to change the information as appropriate, or may not be so. If the information can be changed by the user, the change is realized by, for example, a not-shown receiving unit that receives a change instruction from the user and a changing unit (not shown) that changes the information in accordance with the change instruction. May be. The change instruction received by the receiving unit (not shown) may be received from an input device, information received via a communication line, or information read from a predetermined recording medium, for example. .

  In the above embodiment, each component may be configured by dedicated hardware, or a component that can be realized by software may be realized by executing a program. For example, each component can be realized by a program execution unit such as a CPU reading and executing a software program recorded on a recording medium such as a hard disk or a semiconductor memory. At the time of execution, the program execution unit may execute the program while accessing the storage unit or the recording medium. The program may be executed by being downloaded from a server or the like, or may be executed by reading a program recorded on a predetermined recording medium (for example, an optical disk, a magnetic disk, a semiconductor memory, or the like). Good. Further, this program may be used as a program constituting a program product. Further, the computer that executes the program may be singular or plural. That is, centralized processing may be performed, or distributed processing may be performed.

  Further, the present invention is not limited to the above-described embodiment, and various modifications are possible, and it goes without saying that these are also included in the scope of the present invention.

  As described above, according to the wire feeding device of the present invention, the effect that the buffer amount can be automatically calibrated is obtained, which is useful as a wire feeding device having a wire buffer.

DESCRIPTION OF SYMBOLS 1 Wire feeding apparatus 5 Welding wire 11 1st wire feeding part 12 Wire buffer 13 2nd wire feeding part 14 Buffer amount acquisition part 15 Acquisition part 16 Calibration part 17 Controller 21 Case 22, 25 Wire guide 23 Axis Branch

Claims (3)

A first wire feeding section for feeding a welding wire;
A wire buffer in which the welding wire fed by the first wire feeding unit is buffered;
A second wire feeding section for feeding a welding wire buffered by the wire buffer to a welding torch;
A buffer amount obtaining unit for obtaining a buffer amount that is an amount of the welding wire buffered in the wire buffer;
An acquisition unit for acquiring a force in a length direction of the welding wire buffered by the wire buffer;
A calibration unit that calibrates the buffer amount acquisition unit,
The calibration unit includes
The welding wire is moved so that the buffer amount is reduced by at least one of the first and second wire feeding units, and the buffer amount when the tension acquired by the acquiring unit exceeds the first threshold is set. Set to the minimum value,
The amount of buffer when the pressing force acquired by the acquisition unit exceeds the second threshold by moving the welding wire so that the buffer amount increases by at least one of the first and second wire feeding units. Wire feeding device that sets the maximum value. The feeding of the welding wire by at least one of the first and second wire feeding units is controlled so that the buffer amount acquired by the buffer amount acquiring unit is between the maximum value and the minimum value. The wire feeding device according to claim 1, further comprising a controller. The wire buffer is
A case for receiving a welding wire having an inlet and an outlet for the welding wire, the length from the inlet to the outlet being changed; and
In the case, a wire guide through which the welding wire passes,
A shaft support that pivotally supports at least a part of the wire guide with respect to the case; and
The wire feeding device according to claim 1, wherein the buffer amount acquisition unit acquires a buffer amount according to an angle of the wire guide that is pivotally supported by the shaft support portion.

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