Control Method of Welding Machine

Abstract

Comprising: a first step of detecting the acceleration in the X-axis direction of a torch (60) equipped with an acceleration sensor (310) at each prescribed time interval; a second step of calculating the moving average of the acceleration during the period using the acceleration detected in the first step; and a third step of comparing the number of times of acceleration detection during the period and the number of times E of the case where the absolute value of the difference between the acceleration and the moving average during the period exceeds a threshold value, and restricting the operation of a welding machine having the torch (60) when the ratio of the number of times to the number of detections (= number of times / number of detections) is less than a prescribed value.

Description

Technical Field

[0001] The present disclosure relates to a control method for a welding machine, and particularly to a control method for a welding machine having a torch of a type manually operated by a welding operator. Background Art

[0002] Conventionally, the following technique has been known: a sensor such as an acceleration sensor is installed in a torch manually operated by a welding operator, and arc welding is controlled based on an output signal from the sensor (for example, refer to Patent Documents 1 to 3).

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2013-066906

[0006] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2013-223879

[0007] Patent Document 3: International Publication No. 2019 / 202854 Summary of the Invention

[0008] -Problems to be Solved by the Invention-

[0009] However, in arc welding in which a torch is manually operated, due to a misoperation of the torch or the like, the welding machine may operate at an unexpected timing and generate a welding output. In such a case, not only does the welding operation become unsafe, but also welding defects and a reduction in welding quality may occur.

[0010] However, in the existing structures disclosed in Patent Documents 1 and 2, a technique for preventing the welding machine from operating at an unexpected timing is not disclosed.

[0011] On the other hand, in Patent Document 3, the following is disclosed: when the current flowing through the torch is equal to or less than a specified value and it is detected by an acceleration sensor and an angular velocity sensor that the tip of the torch has not moved for a specified period, the operation of a welding switch provided on the torch is invalidated.

[0012] However, in the structure disclosed in Patent Document 3, the items to be detected involve a plurality of items, and signal processing and control become complicated.

[0013] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a control method for a welding machine that can easily prevent the welding machine from operating at an unexpected timing.

[0014] -Means for Solving the Problems-

[0015] To achieve the above object, a control method for a welding machine according to the present disclosure is a control method for a welding machine having a torch equipped with an acceleration sensor, and is characterized by comprising: a first step of detecting the acceleration of the torch at each predetermined time interval; a second step of calculating a moving average of the acceleration during a predetermined period using the acceleration detected in the first step; and a third step of comparing the number of times of detecting the acceleration during the predetermined period with the number of times when the absolute value of the difference between the acceleration and the moving average during the predetermined period exceeds a predetermined threshold, and restricting the operation of the welding machine when the ratio of the number of detections to the number of times is less than a predetermined value.

[0016] -Advantages of the Invention-

[0017] According to the present disclosure, it is possible to simply prevent the operation of the welding machine at an unexpected timing. In addition, the work safety of the welding operator can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic diagram showing the structure of an arc welding machine according to an embodiment.

[0019] Figure 2 is a schematic diagram showing the appearance of a torch.

[0020] Figure 3 is a schematic diagram showing the internal structure of a torch.

[0021] Figure 4 is a schematic block diagram of the power supply device and the functional blocks of the torch.

[0022] Figure 5 is an example of the time variation of the acceleration in the X-axis direction of the torch.

[0023] Figure 6 is a schematic block diagram of the power supply device and the functional blocks of the torch according to a modified example. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the present disclosure, its applications, or its uses.

[0025] (Embodiment)

[0026] [Structure of Arc Welding Machine and Structure of Torch]

[0027] Figure 1 A schematic diagram showing the structure of the arc welding machine according to the present embodiment. Figure 2 A schematic diagram showing the appearance of the torch, Figure 3Schematic diagram showing the internal structure of the welding torch.

[0028] As Figure 1 shown, the arc welding machine 10 (hereinafter, may be simply referred to as the welding machine 10) includes a power supply device 20, a wire feeding device 30, and a welding torch 60. In addition, a shielding gas, such as CO 2 gas, is supplied from a gas cylinder 80 to the welding torch 60 via a gas hose 81 and the wire feeding device 30. In addition, the shielding gas is adjusted and supplied by a flow regulator (not shown) so that the pressure and flow rate of the shielding gas are at specified values. Further, the gas hose 81 is accommodated inside the torch cable 41, and the power cable 40 and the control cable 50, which will be described later, are also accommodated inside the torch cable 41.

[0029] The power supply device 20 connects the power cable 40 to one of the output terminals 21 and the workpiece cable 42 to the other, and supplies welding power to the welding torch 60 from the power cable 40. Specifically, welding current is supplied to the welding wire 70 passing through the welding torch 60 via the power cable 40 accommodated inside the torch cable 41 and connected to the welding torch 60 and a welding chip (not shown). In addition, the power supply device 20 is configured to send control signals for controlling the wire feeding speed and the welding current flowing through the welding wire 70 to the wire feeding device 30. The functions and internal functional block structures of the power supply device 20 will be described later.

[0030] The wire feeding device 30 includes a wire feeding mechanism (not shown) and a motor 31 that drives the wire feeding mechanism, and feeds the welding wire 70 to the workpiece (welding object) W at a specified speed according to a control signal from the power supply device 20. In addition, the shielding gas supplied from the gas cylinder 80 is supplied to the welding torch 60. Alternatively, the shielding gas may be directly supplied to the welding torch 60 via the flow regulator.

[0031] The control cable 50 is connected to the power supply device 20 and the wire feeding device 30, and is configured to send control signals for controlling the wire feeding speed of the welding wire 70, and to perform various signal interactions between various devices provided in the welding torch 60 and the power supply device 20. In addition, drive power for various devices provided in the welding torch 60 is supplied via the control cable 50. Further, the control cable 50 is configured to send an operation signal of the torch switch 64 that determines the start / stop of welding to the power supply device 20.

[0032] As Figure 2 , 3 shown, the welding torch 60 has a torch body 61, a torch holder 63, a torch switch 64, and a head 62. In addition, the welding wire 70 is held inside the welding torch 60, and the welding wire 70 is fed from the front end of the head 62 to the workpiece W.

[0033] As Figure 2As shown, a display unit 100 and an operation unit 200 are arranged in the torch holder 63. The display unit 100 includes, for example, a display device such as a liquid crystal display or an organic EL display. The display unit 100 performs various displays such as welding conditions. The operation unit 200 includes, for example, devices such as operation buttons (not shown), and outputs an operation signal to various devices provided in the torch 60 or the power supply device 20 through the operation of the welding operator. For example, the display / non-display of the display unit 100 can be switched through the operation of the operation unit 200. In addition, when the display unit 100 is a touch panel, the function of the operation unit 200 can be integrated into the display unit 100, and the operation unit 200 can be omitted.

[0034] In addition, as Figure 3 shown, a sensor unit 300 is installed inside the torch holder 63 and is electrically connected to a control cable 50 passing through the torch cable 41 via a wiring 65. In addition, a torch switch 64 is installed in the torch holder 63, and the torch switch 64 is also electrically connected to the control cable 50 passing through the torch cable 41 via a wiring 66. Operating the torch switch 64, in other words, pressing the torch switch 64, switches between a welding start state and a welding stop state. The welding start state is an ON state in which the wire feeding device 30 operates and a welding current flows through the welding wire 70, and the welding stop state is an OFF state in which the supply of the welding current stops and the wire feeding device 30 also stops. Here, as will be described later, the operation of the torch switch 64 is effective only when it can be determined based on the detection result in the sensor unit 300 that the welding operator is holding the torch 60.

[0035] [Functional block structure of power supply device and torch]

[0036] Figure 4 The schematic structural diagram of the functional blocks of the power supply device and the torch is shown, Figure 5 which shows an example of the time change of the acceleration in the X-axis direction of the torch. In addition, although not shown, as described above, the control cable 50 is connected to the power supply device 20 and the torch 60 via the wire feeding device 30.

[0037] As Figures 2 to 4 shown, in the torch 60, a display unit 100, an operation unit 200, and a sensor unit 300 are provided. The functions of the display unit 100 and the operation unit 200 are as described above.

[0038] As Figure 4As shown, the sensor unit 300 is a device that includes an acceleration sensor 310, an angular velocity sensor 320, a signal processing unit 330 that processes the outputs of these acceleration sensor 310 and angular velocity sensor 320, and these are integrated in one package. Additionally, the acceleration sensor 310 and the angular velocity sensor 320 are sensors that respectively detect changes in acceleration or angular velocity in the three mutually orthogonal axes ( Figure 2 the X-axis, Y-axis, and Z-axis shown) of the three-dimensional space. In other words, the sensor unit 300 is a so-called six-axis sensor. Furthermore, the signal processing unit 330 includes an IC or an LSI. The sensor unit 300 detects the acceleration and angular velocity in each axial direction in the torch 60 and their changes. These values are detected at each predetermined time interval. Additionally, based on the changes in the acceleration and angular velocity in each axial direction and the difference in the position between the predetermined sensor unit 300 and the tip of the head 62 of the torch 60, the moving speed and movement of the tip of the torch 60 are detected.

[0039] In addition, the signal processing unit 330 receives the analog output signals of the acceleration sensor 310 and the angular velocity sensor 320, and performs noise filtering, signal amplification, or digital processing of the analog output signals. Additionally, in this embodiment, the acceleration sensor 310, the angular velocity sensor 320, and the signal processing unit 330 are integrated in one package, but they can also be separately prepared and installed on a printed circuit board. Among the sensor unit 300, the detection signal of the acceleration sensor 310 is used for the effective / invalid determination of the operation of the torch switch 64 described later.

[0040] On the other hand, in the power supply device 20, a control unit 400 and a storage unit 500 are provided. The control unit 400 at least has an arithmetic unit 410, a judgment unit 420, and a welding control unit 430.

[0041] In addition, the control unit 400 is a functional block that executes and implements a specified software on a microcomputer or an LSI, and the arithmetic unit 410, the judgment unit 420, and the welding control unit 430 included therein are the same. Additionally, the arithmetic unit 410, the judgment unit 420, and the welding control unit 430 can also be separately installed on other LSIs.

[0042] The welding control unit 430 among the control unit 400 controls the wire feeding speed of the welding wire 70 fed from the wire feeding device 30. Additionally, the welding control unit 430 controls the welding output, that is, the welding current and welding voltage flowing through the welding wire 70.

[0043] The arithmetic unit 410 performs various arithmetic processes based on the signals output from the signal processing unit 330 of the sensor unit 300, that is, the detection values of the acceleration sensor 310 and the angular velocity sensor 320. For example, it calculates the speed, amplitude, and attitude of the tip of the torch 60, etc.

[0044] The storage unit 500 stores welding conditions, such as the set voltage, set current, and the corresponding wire feed speed. In addition, the storage unit 500 sequentially stores the acceleration of the torch 60 detected by the acceleration sensor 310 at each specified time interval. In the following description, the acceleration A in the X-axis direction is mainly described. X (Hereinafter, simply referred to as acceleration A X ). The arithmetic unit 410 calculates the moving average MA X of the acceleration A X based on the acceleration A stored in the storage unit 500. X (Hereinafter, simply referred to as moving average MA X ). Here, the so-called moving average is a value obtained by shifting the interval and calculating the average value for each preset fixed period. In the present embodiment, this fixed period is the Figure 5 period T shown.

[0045] The determination unit 420 counts the number E of cases where the acceleration A X exceeds the moving average MA X ± the threshold value K during the period T, that is, the number E of cases where the absolute value of the difference between the acceleration A X and the moving average MA X exceeds the threshold value K. Here, the threshold value K is a positive value.

[0046] As Figure 5 shown, the acceleration A X may vary greatly over time. For example, when the welding operator holds the torch 60, due to the influence of hand tremors, the torch 60 moves irregularly and sometimes has large movements. This movement is reflected in the acceleration A X , as Figure 5 shown, during the specified period T, there will be cases where the acceleration A X exceeds the moving average MA X ± the threshold value K. In addition, the value of the threshold value K is appropriately set according to the range of the output signal of the acceleration sensor 310 caused by hand tremors. Therefore, the size and weight of the torch 60 also affect the setting of the threshold value K.

[0047] In addition, the determination unit 420 determines the acceleration A during the specified period T XThe number of detections N is compared with the number E. When the ratio of the number of detections N to the number E (= E / N) is less than a specified value, it is determined that the welder is not holding the welding torch 60. If it is equal to or greater than the specified value, it is determined that the welder is holding the welding torch 60. In the present embodiment, this specified value is set to 0.5, but it is not particularly limited thereto, and other values can be appropriately taken. In addition, the number of detections N is 100, but it is not particularly limited thereto, and other values can be appropriately taken.

[0048] When the welding control unit 430 determines through the determination unit 420 that the welder is not holding the welding torch 60, the operation of the torch switch 64 is invalidated. Therefore, in this state, even if the torch switch 64 is pressed, the wire feeding device 30 does not operate and no welding current flows through the welding wire 70. In other words, the operation of the arc welding machine 10 is restricted.

[0049] On the other hand, when the welding control unit 430 determines through the determination unit 420 that the welder is holding the welding torch 60, the operation of the torch switch 64 is validated. Therefore, the operation restriction of the arc welding machine 10 is released. In this state, if the torch switch 64 is pressed, the wire feeding device 30 operates, and it becomes a welding start state where a specified welding current flows through the welding wire 70.

[0050] [Effects, etc.]

[0051] As described above, the control method of the welding machine according to the present embodiment is a control method for a welding machine 10 having a welding torch 60 equipped with an acceleration sensor 310.

[0052] This control method includes: a first step of detecting the acceleration A of the welding torch 60 at each specified time interval X and a second step of using the acceleration A detected in the first step X to calculate the moving average value MA of the acceleration A X . X In addition, it includes a third step of comparing the number of detections N of the acceleration A during a specified period T

[0053] and the number E of cases where the absolute value of the difference between the acceleration A and the moving average value MA during the specified period T X exceeds a threshold value K. When the ratio of the number of detections N to the number E (= E / N) is less than a specified value, the operation of the arc welding machine 10 is restricted. X with the moving average value MA X

[0054] According to the present embodiment, based on the acceleration A of the welding torch 60 X and its moving average value MA X, limiting the action of the welding machine 10, thereby being able to simply prevent the welding output from occurring at unexpected timing due to malfunction of the welding torch switch 64, etc. This can improve the safety of the welding operator. In addition, it is possible to prevent the occurrence of welding failures such as welding at unexpected positions on the workpiece W.

[0055] Furthermore, unlike the structure disclosed in Patent Document 3, in determining the motion limit of the welding machine 10, only the acceleration A is detected. X Therefore, the calculation process for judgment can be simplified.

[0056] Furthermore, in determining the motion limit of the welding machine 10, the acceleration A is not directly used. X , but use its moving average MA X , so that the judgment accuracy can be improved. This is further explained.

[0057] As is known in the past, the output signal of the acceleration sensor 310 has temperature dependence that changes according to the temperature. Therefore, if the temperature of the surrounding environment changes, the acceleration detected by the acceleration sensor 310 also changes. In addition, there are individual differences in the acceleration sensor 310, so due to the individual differences, the acceleration detected by the acceleration sensor 310 varies between different welding machines 10. In addition, due to the installation error when the acceleration sensor 310 is installed on the mounting substrate not shown in the figure, or the installation error when the sensor unit 300 is installed on the welding torch holder 63, the acceleration detected by the acceleration sensor 310 also varies.

[0058] Thus, the output signal of the acceleration sensor 310, in other words, the acceleration detected by the acceleration sensor 310, has a plurality of variable factors. X To determine the action limit of the welding machine 10, there is a concern that the acceleration A X Due to the detection deviation, the judgment accuracy of the action limitation of the welding machine 10 is reduced.

[0059] On the other hand, according to this embodiment, by using the moving average MA X Since the influence of the variable factors is mitigated, it is possible to accurately determine whether the operation restriction of the welding machine 10 is required.

[0060] In addition, the determination unit 420 may count the following number of times F instead of the number of times E. The number of times F is the acceleration A in the predetermined period T. X The acceleration A during the specified period T X and acceleration A X Standard Deviation SD X (hereinafter referred to as standard deviation SDX ) the number of times the absolute value of the difference exceeds the threshold K1. In this case, in the third step, the acceleration A during a specified period T X the number of detections N, and the acceleration A during the specified period T X and the standard deviation SD X are compared with the number of times F that the absolute value of the difference exceeds the threshold K1. When the ratio (= F / N) of the number of detections N to the number F is less than a specified value, the operation of the welding machine 10 is restricted.

[0061] Thus, similar to the case of the usage times E, it is also possible to simply prevent welding output from occurring at an unexpected timing. In addition, of course, the work safety of the welding operator can be improved and the occurrence of welding defects can be prevented. Additionally, the threshold K1 is a value different from the threshold K. However, it can also be the same value.

[0062] In addition, the operation of the welding machine 10 can also be restricted by a different method. For example, when the standard deviation SD during a specified period T X is below a specified threshold, the determination unit 420 determines that the welding operator is not holding the torch 60 and restricts the operation of the welding machine 10.

[0063] In the third step, when the ratio of the number of detections N to the number E or the number F is less than a specified value, the operation of the torch switch 64 provided on the torch 60 is invalidated.

[0064] By doing so, even if the torch switch 64 is operated, it does not become the welding start state, and the operation of the welding machine 10 can be reliably restricted. Thereby, of course, the occurrence of welding output at an unexpected timing can be reliably prevented, and the work safety of the welding operator can be improved and the occurrence of welding defects can be prevented.

[0065] In addition, in the present embodiment, the acceleration A in the X-axis direction of the torch 60 is shown X and its moving average MA X are used to restrict the operation of the welding machine 10, but it is not particularly limited thereto. For example, the acceleration A in the Y-axis direction Y or the acceleration A in the Z-axis direction Z and its moving average can also be used. In addition, the square root of the sum of squares of the accelerations A X in each axial direction, A Y and A Z can also be used.

[0066] Additionally, the movement of the torch 60 caused by hand tremors is more likely to occur in the plane of the long side direction of the torch 60, which is the Y-axis direction, than in the Z-axis direction. Therefore, by using the acceleration A in the X-axis directionX or the acceleration A in the Y-axis direction Y , it is possible to accurately judge hand tremors and then judge whether the welding operator is holding the welding torch 60, which can improve the judgment accuracy of the operation limit of the welding machine 10.

[0067] In addition, in the present embodiment, an example is shown in which the operation of the welding machine 10 is restricted when the ratio of the detection times N to the times E or F is less than a specified value. However, for example, it is also possible to prohibit the change of the welding conditions of the welding machine 10. In other words, when it is judged that the welding operator is not holding the welding torch 60, it is also possible to prohibit the change of the welding conditions of the welding machine 10.

[0068] By doing so, it is possible to prevent unexpected changes in welding conditions. Thereby, it is possible to prevent the occurrence of welding defects. In addition, it is possible to improve the operation safety of the welding operator.

[0069] In addition, the welding machine 10 according to the present embodiment at least includes: a welding torch 60 equipped with an acceleration sensor 310, and a power supply device 20 electrically connected to the welding torch 60 and supplying welding power to the welding torch 60.

[0070] The power supply device 20 has a control unit 400 and a storage unit 500. The control unit 400 at least has an arithmetic unit 410, a judgment unit 420, and a welding control unit 430.

[0071] The acceleration sensor 310 detects the acceleration of the welding torch 60 at each specified time interval.

[0072] The storage unit 500 sequentially stores the accelerations of each axis of the welding torch 60 detected by the acceleration sensor 310.

[0073] Based on the acceleration A stored in the storage unit 500 X , the arithmetic unit 410 calculates its moving average value MA X .

[0074] The judgment unit 420 counts the number of times E when the absolute value of the difference between the acceleration A X and the moving average value MA X exceeds the threshold value K during a specified period T. In addition, the judgment unit 420 compares the number of detection times N of the acceleration A X during a specified period T with the number of times E when the absolute value of the difference between the acceleration A X and the moving average value MA X exceeds the threshold value K. When the ratio (=E / N) of the detection times N to the number of times E is less than a specified value, it is judged that the welding operator is not holding the welding torch 60.

[0075] When the welding control unit 430 determines, via the determination unit 420, that the welder is not holding the welding torch 60, the operation of the welding machine 10 is restricted.

[0076] With the welding machine 10 of the present embodiment, as described above, it is possible to easily prevent welding output from occurring at an unexpected timing due to a malfunction of the torch switch 64 or the like. Thereby, the working safety of the welder can be improved. In addition, it is possible to prevent the occurrence of welding defects such as welding the workpiece W at an unexpected position.

[0077] In addition, when the welding control unit 430 determines, via the determination unit 420, that the welder is not holding the welding torch 60, the operation of the torch switch 64 is invalidated, thereby restricting the operation of the welding machine 10. Thereby, it is possible to reliably prevent the occurrence of welding output at an unexpected timing, improve the working safety of the welder, and prevent the occurrence of welding defects.

[0078] Alternatively, the arithmetic unit 410 may calculate the standard deviation SD of the acceleration A during the period T based on the acceleration A stored in the storage unit 500. X The determination unit 420 counts the number of times F when the absolute value of the difference between the acceleration A and the standard deviation SD during the period T exceeds the threshold value K1. Alternatively, the determination unit 420 may compare the detection number N of the acceleration A during the period T with the number of times F when the absolute value of the difference between the acceleration A and the standard deviation SD exceeds the threshold value K1. When the ratio (=F / N) of the detection number N to the number of times F is less than a specified value, it is determined that the welder is not holding the welding torch 60. X of the acceleration A during the period T X and the standard deviation SD X during the period T, X and counts the number of times F when the absolute value of the difference therebetween exceeds the threshold value K1. X Furthermore, the determination unit 420 may compare the detection number N of the acceleration A X during the period T with the number of times F when the absolute value of the difference between the acceleration A X and the standard deviation SD exceeds the threshold value K1. When the ratio (=F / N) of the detection number N to the number of times F is less than a specified value, it is determined that the welder is not holding the welding torch 60.

[0079] <Modification Example>

[0080] Figure 6 The schematic configuration diagram of the functional blocks of the power supply device and the welding torch according to the modification example is shown.

[0081] Figure 6 The structure shown is different from the structure shown in that the arithmetic unit 610, the determination unit 620, and the storage unit 500 are provided in the welding torch 60. In addition, the functions of the arithmetic unit 610 and the determination unit 620 are the same as the functions of the arithmetic unit 410 and the determination unit 420 shown. Figure 4 The structure shown is different in that the arithmetic unit 610, the determination unit 620, and the storage unit 500 are provided in the welding torch 60. Figure 4 The functions of the arithmetic unit 610 and the determination unit 620 are the same as the functions of the arithmetic unit 410 and the determination unit 420 shown.

[0082] Further, when the output signal of the sensor unit 300 is sent to the control unit 400 provided in the power supply device 20, a communication unit 630 is provided in the torch 60, and this signal is sent from the communication unit 630 to the welding control unit 430 of the control unit 400 as an isolation signal.

[0083] By this modification example, the same effects as those of the structure shown in the embodiment can be achieved. In other words, it is possible to prevent the occurrence of welding output at an unexpected timing, improve the working safety of the welding operator, and prevent the occurrence of welding defects. In addition, it is possible to prevent the unexpected change of welding conditions, prevent the occurrence of welding defects, and improve the working safety of the welding operator.

[0084] Furthermore, by this modification example, the acceleration and angular velocity of each axis of the torch 60 can be accurately calculated. When the torch cable 41 including the control cable 50 is very long, if the output signal of the sensor unit 300 is small, the attenuation of the signal transmitted through the control cable 50 and input to the control unit 400 becomes large, and it may be difficult to accurately calculate the acceleration and angular velocity of each axis of the torch 60. In such a case, by providing an arithmetic unit 610, a determination unit 620, and a storage unit 500 in the torch 60, the attenuation of the signal in the control cable 50 can be eliminated, and the acceleration and angular velocity of each axis of the torch 60 can be accurately calculated.

[0085] In addition, the arithmetic unit 410 and the determination unit 420 may be assembled and integrated in the signal processing unit 330. Furthermore, the communication unit 630 may be a functional block for transmitting and receiving wireless signals. In this case, a wireless communication unit (not shown) is provided in the power supply device 20, and signals are exchanged between the communication unit 630 and this wireless communication unit.

[0086] In addition, in this application specification, the so-called consumable electrode type arc welding machine 10 using the welding wire 70 has been described as an example, but the arc welding machine 10 may be a non-consumable electrode type arc welding machine such as TIG. However, in this case, since the wire feeding device 30 is not required, power is directly supplied from the power supply device 20 to the torch 60 via the power cable 40. In addition, a welding rod or a filler material feeding device may be arranged instead of the wire feeding device 30. In addition, the torch 60 is directly connected to the power supply device 20 through the control cable 50.

[0087] Industrial Applicability

[0088] The control method of the welding machine of the present disclosure can easily prevent the occurrence of welding output at an unexpected timing based on the acceleration of the torch, and the control method of the welding machine of the present disclosure is useful.

[0089] -Symbol Explanation-

[0090] 10 Arc welding machine (welding machine)

[0091] 20 Power supply device

[0092] 30 Wire feeding device

[0093] 31 Motor

[0094] 40 Power cable

[0095] 41 Torch cable

[0096] 42 Workpiece cable

[0097] 50 Control cable

[0098] 60 Torch

[0099] 61 Torch body

[0100] 62 Head

[0101] 63 Torch holder

[0102] 64 Torch switch

[0103] 70 Welding wire

[0104] 80 Gas cylinder

[0105] 81 Gas hose

[0106] 100 Display unit

[0107] 200 Operation unit

[0108] 300 Sensor unit

[0109] 310 Acceleration sensor

[0110] 320 Angular velocity sensor

[0111] 330 Signal processing unit

[0112] 400 Control unit

[0113] 410, 610 Arithmetic unit

[0114] 420, 620 Judgment unit

[0115] 430 Welding control unit

[0116] 500 Storage unit

[0117] 630 Communication unit

[0118] W Workpiece (object to be welded).

Claims

1. A control method for a welding machine, the welding machine having a torch equipped with an acceleration sensor, the control method comprising: a first step of detecting the acceleration of the torch at each predetermined time interval; a second step of calculating a moving average of the acceleration during a predetermined period using the acceleration detected in the first step; and a third step of comparing the number of times of detecting the acceleration during the predetermined period with the number of times when the absolute value of the difference between the acceleration and the moving average exceeds a predetermined threshold during the predetermined period, and when the ratio of the number of times to the number of detections is less than a predetermined value, determining that the welder is not holding the torch and restricting the operation of the welding machine.

2. A control method for a welding machine, the welding machine having a torch equipped with an acceleration sensor, the control method comprising: a first step of detecting the acceleration of the torch at each predetermined time interval; a second step of calculating a standard deviation of the acceleration during a predetermined period using the acceleration detected in the first step; and a third step of comparing the number of times of detecting the acceleration during the predetermined period with the number of times when the absolute value of the difference between the acceleration and the standard deviation exceeds a predetermined threshold during the predetermined period, and when the ratio of the number of times to the number of detections is less than a predetermined value, determining that the welder is not holding the torch and restricting the operation of the welding machine.

3. The control method for a welding machine according to claim 1 or 2, wherein, in the third step, when the ratio of the number of times to the number of detections is less than a predetermined value, the operation of the torch switch provided on the torch is invalidated.

4. The control method for a welding machine according to claim 1 or 2, wherein, the acceleration is an acceleration related to the movement of the torch in a plane including the long side direction of the torch.

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