welding equipment

Abstract

To provide a welding device that is improved in productivity.SOLUTION: An arc-welding device 1 is provided with a determining part 31 that when a detected result of an encoder 13 by a blowing device 10 does not satisfy a predetermined rotation condition and when a detected result by a temperature sensor 22 does not satisfy a predetermined temperature condition, determines that operation of stopping supply of electric power by a power supply circuit 21 and operation at the time of occurrence of an abnormality including operation of outputting an error display image by a display instrument 40, and otherwise, determines that the operation at the time of occurrence of an abnormality is not necessary.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a welding device that can continue to operate in accordance with temperature conditions even if a cooling fan fails. [Background technology]

[0002] Patent Document 1 discloses a welding device that includes a welding power source that supplies power between a welding electrode and a workpiece, and a fan with multiple blades. This welding device improves maintainability by attaching a fan mounting plate for the fan to the fan mounting portion in an openable and closable manner. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-198772 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention provides a welding device that can continue to operate according to temperature conditions even if the cooling fan fails.

[0005] Patent Document 1 describes improving maintainability by making the fan mounting section openable and closable, but does not disclose any description of a welding device that can continue to operate according to temperature conditions even if the cooling fan breaks down. [Means for solving the problem]

[0006] The present invention includes a fan having a plurality of blades, a motor for rotating the fan, a power supply circuit that supplies power between a welding electrode and a workpiece and is cooled by the air blown by the fan, a rotation detection unit that detects rotation by the motor, a temperature sensor that detects the temperature of the power supply circuit, and a determination unit that, if the detection result of the rotation detection unit does not satisfy a predetermined rotation condition and the detection result of the temperature sensor does not satisfy a predetermined temperature condition, determines that a predetermined abnormality operation is necessary, including at least one of an operation to stop the supply of power by the power supply circuit and an output operation by an output unit that outputs at least one of a predetermined sound, image, and light, and otherwise determines that the predetermined abnormality operation is unnecessary. [Effects of the Invention]

[0007] According to the present invention, it is possible to suppress a decrease in productivity of a welding device. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic perspective view of an arc welding device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram showing the configuration of the arc welding device according to the first embodiment of the present invention. [Figure 3] FIG. 3 is a front view of the fan and its surroundings according to the first embodiment of the present invention. [Figure 4] FIG. 4 is a perspective view of the power supply circuit and its surroundings according to the first embodiment of the present invention. [Figure 5] Fig. 5(a) is a timing chart illustrating a pulse signal output by the encoder according to the first embodiment of the present invention. Fig. 5(b) is a timing chart illustrating a pulse signal output by the encoder according to the first embodiment of the present invention. Fig. 5(c) is a timing chart illustrating a pulse signal output by the encoder according to the first embodiment of the present invention. [Figure 6]FIG. 6 is an explanatory diagram illustrating an error display image output by the display device according to the first embodiment of the present invention. [Figure 7] FIG. 7 is a flowchart illustrating the operation of the control device according to the first embodiment of the present invention. [Figure 8] FIG. 8 is a flowchart illustrating the operation of the control device according to the second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] (Background to the invention) In the conventional welding machine disclosed in Patent Document 1, the power supply circuit of the welding machine is cooled by air blown by a fan. When an abnormality occurs in the fan, such as a broken blade, it is necessary to stop the power supply from the power supply circuit for maintenance. However, welding machine maintenance often requires cumbersome work, such as moving the welding machine from the welding site, and takes many days. Therefore, if welding work is immediately stopped to perform maintenance every time an abnormality such as a broken blade occurs in the fan, there is a problem of reduced productivity.

[0010] In response to this, the inventors of the present application have discovered that even if an abnormality such as broken blades occurs in the fan, it may be possible to continue using the welding machine depending on the temperature around the power supply circuit. Therefore, in the following embodiments, a welding machine configured to determine that it is not necessary to stop the supply of power from the power supply circuit when the temperature of the power supply circuit satisfies a predetermined condition, even if an abnormality such as broken blades occurs in the fan, will be described.

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0012] (Embodiment 1) Fig. 1 is a schematic perspective view of an arc welding apparatus 1 according to embodiment 1. Fig. 2 is a block diagram showing the configuration of the arc welding apparatus 1 according to embodiment 1. The arc welding apparatus 1 includes a blower 10, a power supply circuit 21, a temperature sensor 22, a welding electrode 23, a control device 30, a display 40, and a housing 50.

[0013] As shown in FIG. 2, the blower 10 includes a fan 11, a motor 12, and an encoder 13 as a rotation detector.

[0014] Fig. 3 is a front view of the fan 11 and its surroundings according to embodiment 1. As shown in Fig. 3, the fan 11 has a hub 11a and a plurality of blades 11b protruding from the outer periphery of the hub 11a. The fan 11 is disposed in an opening 51 provided in the outer wall surface of the housing 50 so as to face outward.

[0015] The motor 12 rotates the fan 11 .

[0016] The encoder 13 is an incremental encoder that outputs a pulse signal that rises every time the motor 12 rotates a predetermined angle as a detection result.

[0017] FIG. 4 is a perspective view of the power supply circuit 21 and its surroundings according to the first embodiment. The power supply circuit 21 converts AC power sent from an AC power source (not shown) and supplies the converted power between the welding electrode 23 and the workpiece. The welding electrode 23 is held by a welding torch (not shown). The welding torch (not shown) is provided with a torch switch (not shown) for starting and stopping arc welding. As shown in FIG. 4, the power supply circuit 21 has three semiconductor components 24. Each semiconductor component 24 has a semiconductor chip (not shown) and a resin package 24a that houses the semiconductor chip. The three semiconductor components 24 are attached to a common heat sink 25. The heat sink 25 is made of a metal with high thermal conductivity, such as aluminum or copper. The heat sink 25 is composed of a rectangular main plate 25a and a plurality of rectangular protruding plate portions 25b protruding from one surface of the main plate 25a. The protruding plate portion 25b is formed over the entire longitudinal direction of the main plate portion 25a, with its plate surface facing the short side of the main plate portion 25a. The three semiconductor components 24 are attached to the surface of the main plate portion 25a of the heat sink 25 where the protruding plate portion 25b is not formed, with a gap between them in the longitudinal direction of the main plate portion 25a. A temperature sensor 22 is attached to the surface of the main plate portion 25a of the heat sink 25 where the protruding plate portion 25b is not formed, at a location sandwiched between the two semiconductor components 24. The temperature sensor 22 detects the temperature of the power supply circuit 21. The heat sink 25 is housed in the housing 50. The heat sink 25 is positioned so that air from the fan 11 flows between the protruding plate portions 25b of the heat sink 25 when the fan 11 is rotating. Therefore, the power supply circuit 21 is cooled by the air blown by the fan 11.

[0018] The control device 30 includes a determination unit 31, a display instruction unit 32, and a motor control unit 33. The functions of the control device 30 are realized by, for example, a control board on which a microcomputer is mounted.

[0019] 5(a) to 5(c) are timing charts illustrating pulse signals output by the encoder 13 according to the first embodiment. Note that Fig. 5(b) is a timing chart when the rotation speed of the fan 11 is lower than that of Fig. 5(a). Fig. 5(c) is a timing chart when eccentricity of the motor 12 occurs due to breakage of the blades of the fan 11 according to the first embodiment, for example.

[0020] The determination unit 31 determines whether a predetermined abnormality operation is required based on the pulse signal output by the encoder 13 and the detection result of the temperature sensor 22. Specifically, the determination unit 31 determines that the abnormality operation is required if the pulse signal output by the encoder 13 does not satisfy a pulse condition as a predetermined rotation condition and if a predetermined temperature condition for the detection result of the temperature sensor 22 is not satisfied. On the other hand, in other cases, the determination unit 31 determines that the abnormality operation is not required. Here, the pulse condition includes, for example, a condition that the interval INT (interval) between the timing at which a pulse signal having a waveform as shown in the timing charts of FIGS. 5(a) to 5(c) switches between high and low levels is equal to or less than a predetermined upper threshold, and a condition that the interval INT is equal to or greater than a predetermined lower threshold. In other words, if the pulse signal output by the encoder 13 satisfies the predetermined pulse conditions, it indicates that there is no defect in the blades of the fan 11 and the rotation state of the fan 11 is stable, and if the predetermined pulse conditions are not satisfied, it indicates that there is a defect in the blades of the fan 11 and the rotation state of the fan 11 is unstable or the air flow volume is insufficient.

[0021] The temperature conditions include a condition that the temperature detected by temperature sensor 22 is below a predetermined air temperature threshold when arc welding apparatus 1 is started or when a predetermined time has elapsed since arc welding apparatus 1 entered a standby state where no welding is being performed, and a condition that the temperature detected by temperature sensor 22 is below a predetermined operating temperature threshold when it is determined that the pulse signal does not satisfy the pulse condition. The temperature of a location within housing 50 that is not directly exposed to the wind from fan 11 during the welding process is approximately 20°C higher than the ambient temperature. For example, when power supply circuit 21 is started and an arc is generated between welding electrode 23 and the workpiece when the ambient temperature is 40°C, the temperature detected by temperature sensor 22 rises and saturates at approximately 80°C to 90°C. Furthermore, even after power supply circuit 21 is started, the temperature within housing 50 and the temperature detected by temperature sensor 22 decrease to approximately the same temperature as the ambient temperature or room temperature at the location where power supply circuit 21 is installed after a predetermined time (e.g., 30 to 60 minutes) has elapsed in a standby state. Here, the "standby state" refers to a state in which the user has stopped operating the torch switch (not shown) of the arc welding apparatus 1 (the torch switch is in the OFF state), and the supply of power from the power supply circuit 21 to between the welding electrode 23 and the workpiece to be welded has stopped. The moment the torch switch (not shown) is switched from ON to OFF, the welding process transitions to the standby state. Because the airflow from the fan 11 promotes heat dissipation from the heat sink 25, the temperature detected by the temperature sensor 22 drops more quickly than the temperatures of other components.

[0022] Although the welding process transitions to a standby state the moment the torch switch (not shown) is switched from ON to OFF, welding that intermittently forms multiple weld beads can also be treated as a continuous welding process, and the welding process transitions to a standby state after a predetermined time (e.g., 5 to 20 minutes) has elapsed since the torch switch (not shown) was switched from ON to OFF.

[0023] Furthermore, the determination unit 31 determines at predetermined time intervals whether the temperature detected by the temperature sensor 22 is at a predetermined abnormality detection threshold. If the temperature detected by the temperature sensor 22 is at the predetermined abnormality detection threshold, the determination unit 31 causes the display instruction unit 32 to output an image indicating a temperature abnormality on the display 40. The abnormality detection threshold is set to be about 5°C higher than the operating temperature threshold.

[0024] In the first embodiment, it is assumed that the arc welding device 1 will be used in an environment with an outside air temperature of -10°C to 40°C, and the air temperature threshold is set to 25°C and the operating temperature threshold is set to 90°C to 100°C. However, the air temperature threshold and the operating temperature threshold may be set to other temperatures. As the outside air temperature (environmental temperature) drops, the temperature detected by the temperature sensor 22 also drops. When the determination unit 31 determines that an abnormality operation, which is a response operation in the event of an abnormality, is necessary, it stops the supply of power by the power supply circuit 21, and when it determines that an abnormality operation is not necessary, it continues the supply of power by the power supply circuit 21.

[0025] 6 is an explanatory diagram illustrating an example of an error display image output by the display device 40 according to the first embodiment. The display instruction unit 32 operates based on the determination made by the determination unit 31 as to whether or not an operation to output an error display image is required. Specifically, when the determination unit 31 determines that an operation to be performed when an abnormality occurs is required, the display instruction unit 32 causes the display device 40 to output an error display image as shown in FIG. 6. On the other hand, when the determination unit 31 determines that an operation to be performed when an abnormality occurs is not required, the display instruction unit 32 does not cause the display device 40 to output an error display image.

[0026] Motor control unit 33 controls motor 12 in accordance with the temperature detected by temperature sensor 22 before the start of operation of power supply circuit 21. Specifically, when the temperature detected by temperature sensor 22 before the start of operation of power supply circuit 21 is higher than a predetermined upper air temperature threshold, motor control unit 33 controls motor 12 to increase the rotation speed of fan 11 before the start of welding compared to when the temperature is lower.

[0027] The display 40 is an FPD (flat panel display) such as a liquid crystal display, and outputs an error display image as shown in Fig. 6 in response to an instruction from the display instruction unit 32. That is, in the first embodiment, the abnormality operation is an operation of stopping the power supply from the power supply circuit 21 and an operation of outputting an error display image from the display 40. Note that a 7-segment LED display may be used as the display 40 as long as the display content can be supported.

[0028] Next, the main operation of the arc welding device 1 configured as described above will be described with reference to the flowchart of Fig. 7. Fig. 7 is a flowchart illustrating the operation of the control device 30 of the first embodiment.

[0029] First, arc welding device 1 is started. At this time, power supply circuit 21 is in a standby state and has not yet started supplying power between welding electrode 23 and the workpiece. Next, in (S101), determination unit 31 of control device 30 stores the temperature detected by temperature sensor 22. Thereafter, determination unit 31 receives the temperature detected by temperature sensor 22 at predetermined intervals (e.g., every second).

[0030] When arc welding apparatus 1 is started and power supply circuit 21 is in a standby state and has not yet started supplying power between welding electrode 23 and the workpiece, the detection result of temperature sensor 22 is a temperature corresponding to the ambient temperature or room temperature of the location where arc welding apparatus 1 is used, relative to arc welding apparatus 1. Furthermore, even after power supply circuit 21 is started, the temperature detected by temperature sensor 22 drops to approximately the same temperature as the ambient temperature or room temperature of the location where power supply circuit 21 is installed after a predetermined time (e.g., one hour) has passed in a standby state.

[0031] Restarting the arc welding device 1 after a predetermined time (for example, one hour) has elapsed in the standby state corresponds to starting up the arc welding device 1 at the start of the operation of the flowchart in FIG.

[0032] Next, in (S102), determination unit 31 determines whether or not the welding process is in progress, in which generation of an arc has begun between welding electrode 23 and the work-pieces. If the welding process is in progress, the process proceeds to (S103); if the welding process is not in progress, (S102) is executed again. Here, "the welding process is in progress" means that the user has operated the torch switch (not shown) of arc welding apparatus 1, and power is being supplied between welding electrode 23 and the work-pieces (the torch switch is ON).

[0033] In (S103), the determination unit 31 receives the pulse signal output by the encoder 13 and determines whether the pulse signal output by the encoder 13 satisfies a predetermined pulse condition. If the pulse signal satisfies the predetermined pulse condition, the operation of (S102) is executed again. On the other hand, if the condition is not satisfied, the operation proceeds to (S104). Specifically, if the interval INT between the timings at which the pulse signal switches between high and low levels is equal to or less than a predetermined upper threshold and the interval INT is equal to or greater than a predetermined lower threshold, the operation of (S102) is executed again. On the other hand, if the interval INT exceeds the predetermined upper threshold or is below the predetermined lower threshold, the operation proceeds to (S104).

[0034] In step S104, the determination unit 31 determines whether a temperature condition is satisfied, in which the temperature previously stored when the process in step S101 was executed is less than a predetermined air temperature threshold and the temperature currently detected by the temperature sensor 22 (specifically, the temperature detected by the temperature sensor 22 when it was determined that the pulse signal did not satisfy the pulse condition) is equal to or less than a predetermined operating temperature threshold. If the temperature condition is satisfied, the determination unit 31 causes the power supply circuit 21 to continue supplying power between the welding electrode 23 and the workpiece, and the process in step S102 is executed again. On the other hand, if the temperature condition is not satisfied, the process proceeds to step S105. That is, in the operation of the flowchart in FIG. 7, if the temperature stored in step S101 is less than the predetermined air temperature threshold and the temperature currently detected by the temperature sensor 22 is equal to or less than the predetermined operating temperature threshold, the process in step S102 is executed again while the power supply circuit 21 continues operation. On the other hand, if the temperature stored in (S101) is equal to or higher than the predetermined air temperature threshold, or if the temperature currently detected by the temperature sensor 22 exceeds the predetermined operating temperature threshold, the process proceeds to (S105).

[0035] In (S105), determination unit 31 determines that a predetermined abnormality action is necessary. Then, determination unit 31 causes power supply circuit 21 to stop supplying power between welding electrode 23 and the work-piece. Also, display instruction unit 32 causes display device 40 to output an error display image as shown in FIG. 6.

[0036] Furthermore, if the temperature most recently stored in advance as the outside air temperature for the arc welding device 1 in (S101) is, for example, 25°C or higher, and if the pulse conditions are not met in (S103) during the welding process, it is determined that blade breakage has occurred, and if the temperature conditions are not met in (S104), the supply of power between the welding electrode 23 and the workpiece is stopped by processing in (S105).

[0037] Furthermore, when the outside air temperature is, for example, 40°C in (S101), the temperature of temperature sensor 22 provided in power supply circuit 21 rises to approximately 80°C to 90°C during the welding process. In the first embodiment, if the pulse conditions are not satisfied in (S103) during the welding process and the temperature of temperature sensor 22 exceeds 90°C in (S104), the supply of power between welding electrode 23 and the work-piece is stopped by the process of (S105).

[0038] 7, the determination unit 31 determines at predetermined time intervals whether the temperature detected by the temperature sensor 22 is at a predetermined abnormality detection threshold. If the temperature detected by the temperature sensor 22 is at the predetermined abnormality detection threshold, the determination unit 31 causes the display instruction unit 32 to output an image indicating a temperature abnormality to the display 40.

[0039] Therefore, in the first embodiment, the determination unit 31 determines whether or not an abnormality operation is required based on the pulse signal output by the encoder 13 and the detection result of the temperature sensor 22 that detects the temperature of the power supply circuit 21. The pulse signal output by the encoder 13 of the motor 12 reflects the presence or absence of an abnormality, such as a broken blade. The detection result of the temperature sensor 22 indicates a temperature corresponding to the air temperature at the location where the arc welding apparatus 1 is used. If the temperature of the power supply circuit 21 satisfies a predetermined condition, the determination unit 31 determines that the operation to stop the power supply circuit 21 is unnecessary. As a result, even if an abnormality, such as a broken blade, occurs in the fan 11, i.e., even if the detection result of the determination unit 31 does not satisfy the predetermined rotation condition, the power supply circuit 21 can continue to supply power as long as the detection result of the temperature sensor 22 satisfies the predetermined temperature condition. Therefore, a decrease in productivity of the arc welding apparatus 1 can be suppressed.

[0040] Furthermore, the temperature detected by temperature sensor 22 when arc welding apparatus 1 is started, i.e., before power supply circuit 21 starts operating, is hardly affected by the operation of power supply circuit 21 due to the generation of an arc during the welding process, and is therefore approximately equal to the ambient temperature, i.e., the air temperature, of the location where arc welding apparatus 1 is used. In the embodiment, determination unit 31 determines whether or not operation is required in an emergency based on the temperature detected by temperature sensor 22 when arc welding apparatus 1 is started, and therefore the air temperature of the location where arc welding apparatus 1 is used can be more accurately reflected in the determination of whether or not operation is required in an emergency.

[0041] More specifically, even if the pulse signal does not satisfy the pulse conditions due to a failure of fan 11, if the temperature detected by temperature sensor 22 when arc welding apparatus 1 is started or when a predetermined time has elapsed since it was determined that the welding process is not in progress is below a predetermined air temperature threshold, and if the temperature detected by temperature sensor 22 during the welding process when it is determined that the pulse signal does not satisfy the pulse conditions is equal to or below a predetermined operating temperature threshold, power supply circuit 21 will not stop the power supply (operation) and display 40 will not output an error display image. Therefore, the user can continue the welding work.

[0042] Furthermore, in embodiment 1, when the temperature detected by the temperature sensor 22 before the operation of the power supply circuit 21 as the outside air temperature or room temperature is higher than a predetermined upper temperature threshold, the motor control unit 33 increases the rotation speed of the fan 11 before the start of welding compared to when the temperature is lower. Therefore, the rotation speed of the fan 11 can be relatively reduced when the outside air temperature is below the predetermined upper temperature threshold and relatively low.

[0043] (Embodiment 2) FIG. 8 is a flowchart illustrating the operation of the control device 30 according to the second embodiment. In the second embodiment, if the determination unit 31 determines in step S102 that the welding process is in progress, the process proceeds to step S201. In step S201, the determination unit 31 determines whether the welding current is less than a predetermined current threshold. For example, if the rated current of the welding current is 350 A, the current threshold is set to 0.25 to 0.3 times the rated current, e.g., 90 to 100 A. If the welding current is less than the predetermined current threshold, the determination unit 31 proceeds to step S202. On the other hand, if the welding current is equal to or greater than the predetermined current threshold, the process proceeds to step S203. If the welding current is less than the predetermined current threshold, the determination unit 31 sets the in-operation temperature threshold to a first threshold higher than the second threshold in step S202, and the process proceeds to step S103. If the welding current is equal to or greater than the predetermined current threshold, in (S203), the determination unit 31 sets the in-operation temperature threshold to a second threshold lower than the first threshold, and proceeds to (S103). If the heat-resistant temperature of the semiconductor components 24 of the power supply circuit 21 is equal to or lower than approximately 125°C, for example, the first threshold is set to 95°C to 105°C, and the second threshold is set to 85°C to 95°C, which is approximately 10°C lower than the first threshold.

[0044] Other operations are the same as those in the first embodiment, so the same reference numerals are used for common operations and detailed descriptions thereof will be omitted.

[0045] In this way, in embodiment 2, the in-operation temperature threshold is set higher when the welding current is less than the predetermined current threshold compared to when the welding current is equal to or greater than the predetermined current threshold. This prevents abnormal operation from being performed when maintenance is not required when the welding current is less than the predetermined current threshold, i.e., when the temperature rise of power supply circuit 21 is relatively gradual, thereby reducing the number of maintenance operations and improving productivity.

[0046] In the first and second embodiments, the temperature condition includes (S101), i.e., the condition that the temperature detected by temperature sensor 22 before the start of operation of power supply circuit 21 is below a predetermined air temperature threshold. However, instead of this condition, a condition that the temperature detected by temperature sensor 22 after a predetermined time has elapsed since power supply circuit 21 was stopped may be included. Furthermore, in one arc welding apparatus 1, the temperature condition may include, in one situation, a first condition that the temperature detected by temperature sensor 22 before the start of operation of power supply circuit 21 is below a predetermined air temperature threshold, while in another situation, the temperature condition may include, in place of the first condition, a second condition that the temperature detected by temperature sensor 22 after a predetermined time has elapsed since power supply circuit 21 was stopped is below a predetermined air temperature threshold. If the predetermined time is sufficiently long, for example, set to 30 to 60 minutes, the temperature detected by temperature sensor 22 after the start of operation of power supply circuit 21 will be approximately equal to the ambient air temperature at the location where arc welding apparatus 1 is used.

[0047] In the second embodiment, in step S201, determination unit 31 determines whether the welding current is less than a predetermined current threshold. However, instead of this, in step S201, determination unit 31 may determine whether the welding voltage is less than a predetermined voltage threshold. Specifically, if the welding voltage is less than the predetermined voltage threshold, the process proceeds to step S202, whereas if the welding voltage is equal to or greater than the predetermined voltage threshold, the process proceeds to step S203. This prevents abnormal operation from being performed when maintenance is not required when the welding voltage is less than the predetermined voltage threshold, i.e., when the temperature rise of power supply circuit 21 is relatively gradual, thereby reducing the number of maintenance operations and improving productivity.

[0048] 7 and 8, the determination of whether or not an abnormality operation is required is performed while the power supply circuit 21 is operating. However, the determination of whether or not an abnormality operation is required may also be performed while the power supply circuit 21 is stopped. In the flowcharts of FIGS. 7 and 8, even if the pulse signal does not satisfy the predetermined pulse condition, the abnormality operation is not performed as long as the detection result of the temperature sensor 22 satisfies the predetermined temperature condition. However, even if the pulse signal does not satisfy the predetermined pulse condition, if the detection result of the temperature sensor 22 satisfies the predetermined temperature condition, the display 40 may be configured to output an error display image for the pulse condition while the power supply circuit 21 is stopped.

[0049] In the first and second embodiments, if the determination unit 31 determines in step S104 that the temperature condition is satisfied, the power supply circuit 21 continues to operate and the operation of step S102 is executed again. However, if the determination unit 31 determines in step S104 that the temperature condition is satisfied, the determination unit 31 may continue to operate the power supply circuit 21 and execute the operation of step S102 again, and may also output an output image on the display 40 prompting the user to replace the fan. The abnormality action may not include the display 40 outputting an error display image, but may include, for example, only the power supply circuit 21 stopping the supply of power. The determination unit 31 may determine that the display 40 needs to output an error display image if the pulse signal does not satisfy the predetermined pulse condition, regardless of the detection result of the temperature sensor 22. However, if the pulse signal satisfies the predetermined pulse condition, the determination unit 31 may further determine that the output action is unnecessary. This allows the user to recognize the abnormality in the fan 11 and perform maintenance on the fan 11 during off-time when the arc welding apparatus 1 is not being used.

[0050] Furthermore, the operation in the event of an abnormality may be limited to outputting an error display image on the display 40. For example, the determination unit 31 may not determine whether or not it is necessary to stop the supply of power from the power supply circuit 21, and the user may always determine whether or not the stopping operation is necessary.

[0051] Furthermore, in the above-described first and second embodiments and the modified examples, the arc welding device 1 may be provided with an output unit that outputs at least one of a predetermined sound and light instead of the display 40, and the output unit may output at least one of the predetermined sound and light instead of the error display image. Alternatively, both an output unit that outputs at least one of a predetermined sound and light and the display 40 may be provided, and the user may be made aware of an abnormality by both the output of at least one of a sound and light and the output of the error display image.

[0052] Furthermore, in the above-mentioned first and second embodiments and the modified examples, the pulse condition is that the interval INT is equal to or less than a predetermined upper threshold value and equal to or greater than a predetermined lower threshold value, but it may also be either that the interval INT is equal to or less than a predetermined upper threshold value or that the interval INT is equal to or greater than a predetermined lower threshold value.

[0053] Furthermore, in the first and second embodiments and the modified example, the display 40 is provided as an output unit as part of the arc welding device 1, but it may be provided separately from the arc welding device 1.

[0054] Furthermore, in the above-mentioned embodiments 1, 2, and the modified example, the blower device 10 is provided with the encoder 13 as a rotation detection unit, but the rotation detection unit may also be a fan sensor that detects a predetermined angle of rotation by the motor 12 based on whether or not the light beam emitted from the projector is blocked by the blades before reaching the receiver. [Industrial Applicability]

[0055] The present invention is useful as a technology that can improve the productivity of welding equipment and that allows welding equipment equipped with a fan to continue operation in accordance with temperature conditions even if the fan breaks down. [Explanation of symbols]

[0056] 1. Arc welding equipment 10. Blower 11 Fan 11a Hub 11b Feather 12 motors 13 Encoder (rotation detection unit) 21 Power circuit 22 Temperature sensor 23 Welding electrodes 24 Semiconductor parts 24a package 25 Heatsink 25a Main plate part 25b Projecting plate part 30 Control device 31 Judgment section 32 Display instruction section 33 Motor control unit 40 Display 50 cabinets 51 Opening

Claims

1. a fan having a plurality of blades; a motor that rotates the fan; a power supply circuit that supplies power between the welding electrode and the workpiece and is cooled by the air blown by the fan; a rotation detection unit that detects rotation by the motor; a temperature sensor for detecting the temperature of the power supply circuit; a determining unit that determines that a predetermined abnormality operation is necessary, including at least one of an operation to stop the supply of power by the power supply circuit and an output operation by an output unit that outputs at least one of a predetermined sound, image, and light, when the detection result of the rotation detection unit does not satisfy a predetermined rotation condition and a predetermined temperature condition for the detection result of the temperature sensor is not satisfied, and that the predetermined abnormality operation is not necessary in other cases.

2. 2. The welding device according to claim 1, wherein the temperature condition includes a condition that the temperature detected by the temperature sensor is less than a predetermined air temperature threshold before the power supply circuit starts operating or after a predetermined time has elapsed since the power supply circuit is stopped.

3. 3. The welding device according to claim 1, wherein the temperature condition includes a condition that the temperature detected by the temperature sensor when it is determined that the detection result of the rotation detection unit does not satisfy the predetermined rotation condition is equal to or lower than a predetermined operating temperature threshold value.

4. the rotation detection unit outputs a pulse signal that rises every time the motor rotates a predetermined angle; 4. The welding device according to claim 1, wherein the predetermined rotation condition includes at least one of a condition that an interval between the timing at which the pulse signal is switched between a high level and a low level is equal to or less than a predetermined upper threshold, and a condition that the interval between the timing is equal to or greater than a predetermined lower threshold.

5. 5. The welding device according to claim 4, wherein the determining unit determines whether the predetermined abnormality operation is required based on at least one of a welding current and a welding voltage.

6. The welding device according to any one of claims 1 to 5, further comprising a motor control unit that controls the motor in accordance with the temperature detected by the temperature sensor before the power supply circuit starts operating.

7. 7. The welding device according to claim 6, wherein the motor control unit controls the motor to increase the rotation speed of the fan before starting welding when the temperature detected by the temperature sensor before operation of the power supply circuit is higher than a predetermined upper air temperature threshold, compared to when the temperature is lower.

8. the predetermined abnormality operation does not include the output operation, The welding device according to any one of claims 1 to 7, characterized in that the determination unit determines that the output operation is necessary when the detection result of the rotation detection unit does not satisfy the predetermined rotation condition, and further determines that the output operation is unnecessary when the detection result of the rotation detection unit satisfies the predetermined rotation condition.

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