Wire feeding amount measuring device and wire feeding amount measuring method

Abstract

To provide a wire feeding amount measuring device and a wire feeding amount measuring method that can measure feeding amount of a wire without affecting the wire to be a welding material.SOLUTION: A wire feeding amount measuring device 30 is mounted in a wire feeding device 20. The wire feeding device 20 has a guide roller 26 for guiding a wire 21 to be used for welding. The guide roller 26 is mounted with a magnetic position marker rotating together with the guide roller 26 thereon. The magnetic sensor 32 outputs an output signal according to a rotation angle of the guide roller 26 and the magnetic position marker. The wire feeding amount measuring device 30 measures feeding amount of the wire 21 on the basis of the output signal of the magnetic sensor 32.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a wire feed rate measuring device for measuring the feed rate of wires such as consumable electrodes and welding wires, and a wire feed rate measuring method.

Background Art

[0002] Patent Document 1 describes a wire feed rate measuring device for measuring the moving speed of a wire (consumable electrode or welding wire). In the wire feed rate measuring device described in Patent Document 1, magnets are arranged to face each other with the wire sandwiched therebetween, and the moving speed of the wire is measured based on the electrical resistance of a magnetoresistive element installed between the magnet and the wire.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the wire feed rate measuring device described in Patent Document 1, since a magnet is arranged near the wire, the wire may be magnetized. In welding using various steel types such as carbon steel, heat-resistant steel, and 9% nickel steel as the base material, if a magnetized wire is used, magnetic blow may occur due to the wire. When magnetic blow occurs, the arc may deflect in a direction unintended by the operator, and the welding quality may deteriorate.

[0005] In addition, in order to accurately measure the moving speed of the wire, it is necessary to arrange a magnet and a magnetoresistive element near the wire being fed. In order to arrange the magnet and the magnetoresistive element near the wire being fed, it is necessary to disassemble the wire feeding device that feeds the wire. Therefore, the wire feeding speed measuring device described in Patent Document 1 needs to disassemble the wire feeding device every time it is attached and detached (attached and removed), and the attachment and detachment are not easy.

[0006] Therefore, an object of the present invention is to provide a wire feeding amount measuring device and a wire feeding device that can measure the feeding amount of a wire without affecting the wire. Another object of the present invention is to provide a wire feeding amount measuring device that is easily attachable to and detachable from a wire feeding device.

Means for Solving the Problems

[0007] In order to solve the above problems, a wire feeding amount measuring device according to an example of an embodiment of the present invention is attached to a wire feeding device having a guide roller for guiding a wire used for welding, and measures the feeding amount of the wire from the wire feeding device. A wire feeding amount measuring device, comprising: a magnetic position marker attached to the guide roller and rotating together with the guide roller; and a magnetic sensor that outputs an output signal corresponding to the rotation angle of the guide roller and the magnetic position marker, and measures the feeding amount of the wire based on the output signal of the magnetic sensor.

[0008] Preferably, the wire feeding amount measuring device further includes a bracket member attached to the guide roller and rotating together with the guide roller, and the magnetic position marker may be attached to the guide roller via the bracket member.

[0009] Preferably, the wire feeding amount measuring device further includes two mounting blocks and a frame member. The wire feeding device has a base member including two base pillar portions, and when the guide roller is disposed between the two base pillar portions, each of the two mounting blocks includes an adsorption magnet capable of switching between a state of being adsorbed to the base pillar portion by magnetic force and a state of not being adsorbed to the base pillar portion. The two mounting blocks are attached to the frame member with a space corresponding to the interval between the two base pillar portions. The magnetic sensor is attached to the frame member between the two mounting blocks. When each of the two mounting blocks is adsorbed to the base pillar portion by the adsorption magnet, the frame member is attached to the wire feeding device. When the frame member is attached to the wire feeding device, the magnetic sensor may face the magnetic position marker attached to the guide roller.

[0010] Preferably, the magnetic sensor of the wire feeding amount measuring device may be capable of changing the attachment position to the frame member between the two mounting blocks.

[0011] Preferably, each of the two mounting blocks of the wire feeding amount measuring device may be capable of adjusting the interval between the two mounting blocks by changing the attachment position to the frame member.

[0012] Preferably, the wire feeding amount measuring device further includes an arithmetic unit that calculates the feeding amount of the wire based on the output signal from the magnetic sensor. The arithmetic unit receives the output signal corresponding to the rotation angle of the guide roller from the magnetic sensor at each specified measurement interval. The arithmetic unit calculates the feeding speed at which the wire is fed based on the difference between the output signals at each measurement interval, the measurement interval, and the diameter dimension of the guide roller. The arithmetic unit may calculate the feeding amount of the wire based on the calculated feeding speed.

[0013] Preferably, the arithmetic unit of the wire feeding amount measuring device calculates the wire feeding amount based on the feeding speed, the diameter dimension of the wire, and the specific gravity of the wire.

[0014] Preferably, as an example of an embodiment according to the present invention, a wire feeding amount measuring method measures the wire feeding amount from a wire feeding device having a guide roller for guiding a wire used for welding, the wire feeding amount measuring device measuring the wire feeding amount based on an output signal of a magnetic sensor that outputs an output signal corresponding to a rotation angle of a magnetic position marker attached to the guide roller and rotating together with the guide roller.

Advantages of the Invention

[0015] According to the wire feeding amount measuring device and the wire feeding amount measuring method as an example of an embodiment according to the present invention, since no magnetic field is directly applied to the wire for measuring the wire feeding amount, the wire is not magnetized along with the measurement of the wire feeding amount. Therefore, according to the wire feeding amount measuring device and the wire feeding amount measuring method of the present invention, it is possible to measure the wire feeding amount without affecting the wire. Further, since the wire feeding amount is measured using a magnetic sensor, unlike the measurement using an optical sensor, the measurement result is not affected by the arc light generated during welding. Also, the possibility that the measurement result is affected by dust or oil adhered to the wire feeding amount measuring device and becomes unstable is reduced.

[0016] Further, according to the wire feeding amount measuring device and the wire feeding amount measuring method of the present invention, since the object to be directly measured is the guide roller instead of the wire, a magnetic sensor or the like for measurement can be arranged at a position away from the wire. Therefore, according to the wire feeding amount measuring device and the wire feeding amount measuring method of the present invention, it is not necessary to disassemble the wire feeding device for measuring the wire feeding amount, and it is easy to attach and detach a magnetic sensor or the like to and from the wire feeding device.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0018] With reference to FIG. 1, a welding system 10 including a wire feeding amount measuring device 30 as an example of an embodiment of the present invention will be described. FIG. 1 is a diagram schematically showing a welding operation performed in the welding system 10 including the wire feeding amount measuring device 30. In the welding system 10, a wire feeding amount measuring method as an example of an embodiment of the present invention is implemented.

[0019] The welding system 10 includes a welding base material 11, a welding torch 13, a wire feeding device 20, and an arithmetic unit 40. Although not shown in FIG. 1, the welding system 10 includes a power supply device. The power supply device supplies power (for example, 10 kW to 100 kW) required for the welding operation to the welding system 10.

[0020] In the welding system 10 of FIG. 1, semi-automatic arc welding is performed. The wire feeder 20 is connected to the power supply device by the torch-side cable 18. Generally, the torch-side cable 18 is a high-voltage wire. The wire feeder 20 feeds the wire 21 supplied with current from the power supply device to the welding torch 13. In this specification, the wire used for welding (such as a consumable electrode for welding or a welding wire) is simply referred to as the wire 21. For example, the wire 21 is a conductive filler material. Examples of the wire used for welding include a solid wire (bare wire) in which a filler material (such as metal) is in the shape of a wire, a flux-cored wire in which flux is enclosed in the wire, and a stranded wire in which a plurality of wires are gathered together. Any of these types of wires can be used as the wire 21 in the welding system 10 of FIG. 1.

[0021] The welding torch 13 is disposed near the weldment 11 that is the object of the welding operation. The tip of the wire 21 fed from the wire feeder 20 is exposed from the tip of the welding torch 13. The weldment 11 is connected to the power supply device by the base material side cable 14 that conducts with the weldment 11 via a clamping device or the like. Generally, the base material side cable 14 is a low-voltage wire (ground wire).

[0022] When the tip of the wire 21 comes into contact with the weldment 11 and then leaves the weldment 11, an arc is generated at the tip of the wire 21 due to the energization between the wire 21 and the weldment 11. Due to the heat of the arc, the weldment 11 and the wire 21 are melted, and the welding operation on the weldment 11 is executed.

[0023] Although not shown in FIG. 1, the welding torch 13 is also connected to a source of shielding gas (such as a cylinder). When an arc is generated, the welding torch 13 injects a shielding gas that protects the arc from the atmosphere around the wire 21.

[0024] The wire 21 that melts due to the generation of an arc is consumed as the welding operation progresses. However, the wire feeding device 20 continuously feeds the wire 21 to the welding torch 13, enabling the welding operation to be continuously executed.

[0025] In FIG. 1, the wire 21 is wound around a spool - shaped reel 22. The wire feeding device 20 pulls out the wire 21 from the reel 22 and guides it to the wire guide path 28, thereby feeding the wire 21 to the welding torch 13.

[0026] The wire feeding device 20 is supported by a base member 25. The wire feeding device 20 also has a guide roller 26 for guiding the wire 21. The guide roller 26 is disposed at a position surrounded by the base member 25. When the guide roller 26 rotates with its outer peripheral surface in contact with the wire 21, the wire 21 of a length corresponding to the rotation amount of the guide roller 26 is fed to the welding torch 13.

[0027] In FIG. 1, a wire feeding amount measuring device 30 is attached to the wire feeding device 20. The wire feeding amount measuring device 30 measures the feeding amount of the wire 21 from the wire feeding device 20. Here, the feeding amount of the wire 21 refers to the weight of the portion of the wire 21 that has been fed to the welding torch 13. The wire feeding amount corresponds to the consumption amount of the wire 21 due to the welding operation.

[0028] The wire feeding amount measuring device 30 includes a magnetic sensor 32. The magnetic sensor 32 outputs an output signal corresponding to the rotation amount of the guide roller 26. The output signal of the magnetic sensor 32 is transmitted to the arithmetic unit 40 via the sensor communication line 41. The arithmetic unit 40 is a unit capable of performing numerical calculations based on an electrical signal. For example, a computer is used as the arithmetic unit 40. The arithmetic unit 40 calculates the feeding amount of the wire 21 based on the output signal of the magnetic sensor 32.

[0029] Referring to FIG. 2, the wire feeding amount measuring device 30 will be described in more detail. FIG. 2 is an enlarged view showing the wire feeding amount measuring device 30 and the wire feeding device 20 of FIG. 1. The wire feeding amount measuring device 30 in FIG. 2 includes a frame member 31, two mounting blocks 34, and a magnetic sensor 32. Although not shown in FIG. 2, the wire feeding amount measuring device 30 is attached to the guide roller 26 and includes a magnetic position marker 60 (FIGS. 3 and 4) that rotates together with the guide roller 26.

[0030] The base member 25 that supports the wire feeding device 20 in FIG. 2 includes two base column portions 25a. The base column portions 25a are typically made of metal (for example, steel). In FIG. 2, the base column portions 25a stand side by side in the left - right direction in the figure. The wire feeding device 20 has a plurality of rollers (including the guide roller 26) for guiding the wire 21, and these rollers are arranged between the base column portions 25a in the left - right direction of FIG. 2. These rollers are arranged at positions away from the base column portions 25a in the direction perpendicular to the paper surface (depth direction).

[0031] Among the plurality of rollers of the wire feeding device 20, in addition to the guide roller 26, various rollers are included. In FIG. 2, a correcting roller 23 and a pressing roller 24 are shown. In FIG. 2, two correcting rollers 23 are shown, and the two correcting rollers 23 sandwich the wire 21 from above and below. The correcting roller 23 corrects the wire 21 drawn from the reel 22 and having a curl into a straight shape. The pressing roller 24 presses the wire 21 against the guide roller 26. Thereby, the pressing roller 24 prevents slippage between the guide roller 26 and the wire 21. The wire feeding device 20 may have various mechanical parts in addition to these rollers.

[0032] The frame member 31 of the wire feeding amount measuring device 30 is arranged so as to span between the two base pillar portions 25a. Further, the frame member 31 is arranged at the same height as the guide roller 26. The magnetic sensor 32 is attached to the frame member 31 arranged at the same height as the guide roller 26, and is arranged so as to face the guide roller 26.

[0033] The two mounting blocks 34 are attached to the frame member 31. In FIG. 2, the two mounting blocks 34 are respectively arranged at the upper surface and the left and right end portions in the lateral direction of the frame member 31. Each of the two mounting blocks 34 can adjust the interval between the two mounting blocks 34 by changing the mounting position with respect to the frame member 31.

[0034] In FIG. 2, the two mounting blocks 34 are respectively attached to the frame member 31 via the block fixing plate 36 and the block fixing screw 36a. On the front surface of the frame member 31 (the surface exposed to the outside of the wire feeding device 20 shown in FIG. 2), a block interval adjustment groove 31a is formed along the longitudinal direction of the frame member 31 (the direction spanning between the base pillar portions 25a, the left and right direction in the figure). The block fixing plate 36 is arranged so as to straddle both the block interval adjustment groove 31a and the mounting block 34, and the mounting block 34 is attached to the frame member 31 by fastening the block fixing screw 36a between the block fixing plate 36 and the block interval adjustment groove 31a, and between the block fixing plate 36 and the mounting block 34.

[0035] The block fixing plate 36 in FIG. 2 has an L-shaped configuration. One arm of the L-shape of the block fixing plate 36 extends in the direction along the block interval adjustment groove 31a (the left and right direction in the figure), and the other arm of the L-shape extends in the direction connecting the block interval adjustment groove 31a and the mounting block 34 (the vertical direction in the figure). The block fixing screw 36a is attached to one block fixing plate 36 at three locations: the tip of one arm of the L-shape, the tip of the other arm of the L-shape, and the confluence of one arm and the other arm of the L-shape.

[0036] When the attachment position of the attachment block 34 with respect to the frame member 31 is changed, the block fixing screw 36a is loosened, and the block fixing plate 36 is moved along the frame member 31 together with the attachment block 34, whereby the attachment position is changed. Here, for the movement and fixing of the block fixing plate 36, a T-shaped groove and a T-shaped nut (not shown in the drawings) may be used.

[0037] For example, the block interval adjustment groove 31a may be a groove having a T-shaped cross section, and the T-shaped nut may be arranged slidably within the block interval adjustment groove 31a. And the T-shaped nut may be provided with a screw hole that can be screwed together with the block fixing screw 36a. In this case, after the T-shaped nut is slid to an appropriate position within the block interval adjustment groove 31a, the block fixing plate 36 and the T-shaped nut are fastened by the block fixing screw 36a, whereby the movement and fixing of the block fixing plate 36 with respect to the frame member 31 become easy.

[0038] Also, each of the two attachment blocks 34 in FIG. 2 includes a detachable dial 34a and an adsorption magnet 34b. The detachable dial 34a is exposed from the outer surface of the attachment block 34, while the adsorption magnet 34b is arranged inside the attachment block 34. The adsorption magnet 34b can be switched between a state of being adsorbed to the metal base pillar portion 25a by magnetic force and a state of not being adsorbed to the base pillar portion 25a. For example, as the detachable dial 34a rotates, the posture of the adsorption magnet 34b within the attachment block 34 changes, whereby the state of the adsorption magnet 34b being adsorbed to the base pillar portion 25a and the state of not being adsorbed can be switched.

[0039] When the wire feed rate measuring device 30 is attached to the wire feeding device 20, first, with the adsorption magnet 34b not adsorbed to the base pillar portion 25a, the two mounting blocks 34 are adjusted in distance so as to be attached to the frame member 31 with a distance corresponding to the distance between the two base pillar portions 25a. With the two mounting blocks 34 having the adjusted distance each brought into contact with the two base pillar portions 25a, the adsorption magnet 34b is switched to the state of being adsorbed to the base pillar portion 25a. Then, each of the two mounting blocks 34 adsorbs to the base pillar portion 25a by the adsorption magnet 34b with a distance corresponding to the distance between the two base pillar portions 25a, whereby the frame member 31 is attached to the wire feeding device 20. Since the distance between the two mounting blocks 34 is adjustable, the wire feed rate measuring device 30 can be attached to wire feeding devices 20 of various dimensions. Also, by using the adsorption magnet 34b that can be switched between the state of being adsorbed to the base pillar portion 25a and the state of not being adsorbed, the attachment and detachment of the wire feed rate measuring device 30 to and from the wire feeding device 20 are easy. Specifically, by simply operating (rotating) the attachment / detachment dial 34a, it is possible to switch between the state where the wire feed rate measuring device 30 is attached to the wire feeding device 20 and the state where the wire feed rate measuring device 30 is detached from the wire feeding device 20.

[0040] When the frame member 31 is attached to the wire feeding device 20, it is preferable that the magnetic sensor 32 faces the guide roller 26 (or the magnetic position marker 60 attached to the guide roller 26). Here, although it will be described later in detail with reference to FIG. 8, it is also preferable that the magnetic sensor 32 can change its attachment position to the frame member 31 between the two mounting blocks 34. When the magnetic sensor 32 does not face the guide roller 26 or the magnetic position marker 60, the position of the magnetic sensor 32 may be adjusted.

[0041] Next, with reference to FIGS. 3 and 4, an example of the positional relationship among the magnetic sensor 32, the magnetic position marker 60, the bracket member 50, and the guide roller 26 and the way they are attached will be described. FIG. 3 is a plan view showing the positional relationship among the magnetic sensor 32, the magnetic position marker 60, the bracket member 50, and the guide roller 26. FIG. 4 is an exploded perspective view showing the way the bracket member 50 and the magnetic position marker 60 are attached to the guide roller 26. As shown in FIG. 4, the wire 21 is guided by a wire groove 26a formed along the outer peripheral surface of the guide roller 26. By being guided by the wire groove 26a, the wire 21 is guided without shifting in a direction parallel to the rotation axis of the guide roller 26.

[0042] Also, with reference to FIGS. 5, 6, and 7, an example of the structure of the bracket member 50 will be described. FIG. 5 is a cross-sectional view showing the structure of the bracket member 50. FIG. 6 is a view showing the surface of the bracket member 50 on the side of the guide roller 26. FIG. 7 is a view showing the surface of the bracket member 50 on the side of the magnetic position marker 60.

[0043] First, as shown in FIGS. 3 and 4, a guide roller nut 27 for attaching the guide roller 26 to the wire feeding device 20 is attached to the guide roller 26. The guide roller nut 27 is in the shape of a hexagon nut in FIGS. 3 and 4. This guide roller nut 27 is attached to the rotation axis of the guide roller 26 and rotates together with the guide roller 26.

[0044] A bracket member 50 is attached to the guide roller 26. The bracket member 50 is a substantially cylindrical member as shown in FIGS. 3, 4, and 5, and is manufactured by cutting an aluminum material, for example. Note that as the aluminum material that forms the base of the bracket member 50, it is desirable that the material be insulated by anodizing treatment that forms an anodic oxide film. Depending on the structure of the wire feeding device 20, the guide roller 26 may be conductive during the wire feeding operation of the wire 21. However, if the material of the bracket member 50 is insulated by anodizing treatment, it is possible to prevent the conductive state of the guide roller 26 from affecting the detection by the magnetic sensor 32. The bracket member 50 is attached to the guide roller 26 with its cylindrical axis aligned with the rotation axis of the guide roller 26. Specifically, as shown in FIGS. 3, 5, and 6, a bracket recess 51 is provided on the surface of the bracket member 50 on the side of the guide roller 26, and a guide roller nut 27 is received in the bracket recess 51. Then, as shown in FIGS. 4 and 6, a plurality of circumferential screw holes 52 are formed along the outer periphery of the bracket recess 51. By screwing bracket mounting screws 52a into each of the plurality of circumferential screw holes 52, the bracket mounting screws 52a press the guide roller nut 27 from a plurality of directions, so that the bracket member 50 is attached to the guide roller 26 so as to rotate together with the guide roller 26.

[0045] Then, a magnetic position marker 60 is attached to the bracket member 50. The magnetic position marker 60 is a substantially cylindrical member including a marker magnet 66, as shown in FIG. 4. The marker magnet 66 is embedded in one of the cylindrical surfaces (the surface on the magnetic sensor 32 side) of the magnetic position marker 60. As the magnetic position marker 60 rotates together with the guide roller 26, the magnetic field generated around the marker magnet 66 changes. The magnetic sensor 32 includes a detection element (e.g., a Hall element) on the detection surface 32a facing the marker magnet 66 to detect the change in the magnetic field accompanying the change in the posture of the marker magnet 66. A marking 67 serving as a rotation angle reference is provided at a point on the outer peripheral surface of the magnetic position marker 60. The magnetic sensor 32 can detect the rotation angle of the magnetic position marker 60 from the reference posture, for example, with the magnetic position marker 60 in a state where the marking 67 faces the direction of the sensor communication line 41 with respect to the magnetic sensor 32 (downward) as the reference posture.

[0046] As shown in FIGS. 3 and 4, the magnetic position marker 60 is provided with a plurality (here, two) of threaded holes 63 parallel to the cylindrical axis. Further, as shown in FIGS. 3, 4, 5, and 7, the bracket member 50 is provided with a plurality (here, two) of axial screw holes 53 parallel to the cylindrical axis. The magnetic position marker 60 is aligned with the bracket member 50 such that the threaded hole 63 and the axial screw hole 53 communicate with each other, and the marker mounting screw 65 fastens the threaded hole 63 and the axial screw hole 53, whereby the magnetic position marker 60 is attached to the bracket member 50. As shown in FIGS. 3, 5, and 7, a bracket convex portion 54 protruding in the axial direction of the cylindrical shape is provided on the surface of the bracket member 50 on the side of the magnetic position marker 60. On the other hand, as shown in FIG. 3, a marker concave portion 64 recessed in the axial direction of the cylindrical shape is provided on the surface of the magnetic position marker 60 on the side of the bracket member 50. By aligning the bracket member 50 and the magnetic position marker 60 such that the bracket convex portion 54 is received in the marker concave portion 64, the axial alignment between the bracket member 50 and the magnetic position marker 60 can be easily performed. As described above, the magnetic position marker 60 is attached to the guide roller 26 via the bracket member 50 and rotates together with the guide roller 26.

[0047] As shown in FIG. 3, the magnetic sensor 32 is arranged at a distance from the magnetic position marker 60. Therefore, the magnetic sensor 32 does not affect the rotation of the guide roller 26 to which the magnetic position marker 60 is attached, and thus the feeding of the wire 21. Further, since the magnetic position marker 60 is attached to the guide roller 26 via the bracket member 50, the marker magnet 66 of the magnetic position marker 60 is arranged at a position sufficiently far from the wire 21 guided by the guide roller 26. Also, since the marker magnet 66 only needs to be able to detect the rotation angle by the magnetic sensor 32, it is not necessary to generate a strong magnetic field. Therefore, the magnetic field by the marker magnet 66 does not affect the wire 21.

[0048] Also, when the form of the guide roller 26 is different from that shown in FIGS. 3 and 4 (for example, when the nut 27 for the guide roller is not hexagonal), a bracket member 50 manufactured according to the form of the guide roller 26 may be used. That is, by replacing the bracket member 50 as needed without changing the shape of the magnetic position marker 60, it is possible to attach the magnetic position marker 60 to guide rollers 26 of various forms.

[0049] Next, with reference to FIG. 8, an example of how to attach the magnetic sensor 32 to the frame member 31 will be described. FIG. 8 is a diagram showing a state in which the magnetic sensor 32 is attached to the frame member 31.

[0050] On the back surface of the frame member 31 (the surface exposed to the inside mechanism side of the wire feeding device 20, the surface opposite to the front surface to which the block fixing plate 36 is attached), a sensor position adjustment groove 31b is formed along the length direction of the frame member 31. Two screw-through holes 32b are formed in the magnetic sensor 32, and the magnetic sensor 32 is attached to the frame member 31 by fastening a sensor mounting screw 37 between the screw-through hole 32b and the sensor position adjustment groove 31b. By changing the position of the sensor mounting screw 37 with respect to the sensor position adjustment groove 31b, the attachment position of the magnetic sensor 32 with respect to the frame member 31 can be changed. Note that the attachment position of the magnetic sensor 32 with respect to the frame member 31 may be a position facing the guide roller 26 between the two attachment blocks 34, as shown in FIG. 2.

[0051] Note that, for the movement and fixation of the magnetic sensor 32, a T-shaped groove and a T-shaped nut (not shown in FIG. 8) may be used. For example, the sensor position adjustment groove 31b may be a groove having a T-shaped cross section, and the T-shaped nut may be arranged to be slidable within the sensor position adjustment groove 31b. And, the T-shaped nut may be provided with a screw hole that can be screwed together with the sensor mounting screw 37. In this case, after the T-shaped nut is slid to an appropriate position within the sensor position adjustment groove 31b, the screw through hole 32b and the T-shaped nut are fastened by the sensor mounting screw 37, facilitating the movement and fixation of the magnetic sensor 32 with respect to the frame member 31.

[0052] Since the mounting position of the magnetic sensor 32 with respect to the frame member 31 can be changed, it becomes possible to arrange the magnetic sensor 32 at an appropriate position where accurate measurement can be performed in accordance with the arrangement of the guide roller 26 within the wire feeding device 20.

[0053] Next, with reference to FIGS. 2 and 9, an example of a method for measuring the supply amount of the wire 21 based on the output signal of the magnetic sensor 32 will be described. FIG. 9 is a diagram showing the relationship between the rotation angle A of the guide roller 26 and the supply amount of the wire 21.

[0054] Since the magnetic sensor 32 in FIG. 2 outputs an output signal corresponding to the rotation angle of the magnetic position marker 60 attached to the guide roller 26, the arithmetic unit 40 connected to the magnetic sensor 32 by the sensor communication line 41 can calculate the rotation angle of the guide roller 26 based on the output signal of the magnetic sensor 32.

[0055] The arithmetic unit 40 receives, at each specified measurement interval, an output signal corresponding to the rotation angle of the guide roller 26 (and the magnetic position marker 60) from the magnetic sensor 32. The specified measurement interval is, for example, a time interval specified by the user of the wire supply amount measuring device 30 during measurement, or a time interval predetermined before measurement (for example, 0.5 seconds).

[0056] The magnetic sensor 32 outputs an output signal according to how much the guide roller 26 (specifically, the magnetic position marker 60 attached to the guide roller 26) has rotated from the reference posture. For example, when the guide roller 26 is in the reference posture (0°), the magnetic sensor 32 outputs an output signal with a lower limit value (for example, a voltage signal of 0V), and when the guide roller 26 is in a posture rotated 359° clockwise from the reference posture, it outputs an output signal with an upper limit value (for example, a voltage signal of 10V). Also, when the rotation angle of the guide roller 26 is between 0° and 359°, the magnetic sensor 32 outputs an output signal (a voltage signal between 0V and 10V) that increases linearly with respect to the magnitude of the rotation angle, for example.

[0057] Assume that at a certain time t0, a point P0 on the outer circumference of the guide roller 26 was in contact with a point W0 on the wire 21. Then, as shown in FIG. 9, while a time of measurement interval Δt has elapsed from time t0, the guide roller 26 rotates by a rotation angle A in the clockwise C direction, and at time t1 (= t0 + Δt), it is assumed that a point P1 on the outer circumference of the guide roller 26 comes into contact with a point W1 on the wire 21. In this case, during the measurement interval Δt, the wire 21 has been fed to the welding torch 13 by the distance between the point W0 and the point W1 on the wire 21. Hereinafter, the length by which the wire 21 has been fed during the measurement interval Δt (the distance between the point W0 and the point W1) is referred to as the feed length L.

[0058] Since the wire 21 is guided in contact with the outer circumferential surface of the guide roller 26 (specifically, the wire groove 26a in FIG. 4), the magnitude of the feed length L by which the wire 21 is fed to the welding torch 13 while the guide roller 26 rotates by the rotation angle A coincides with the arc length of the guide roller 26 corresponding to the rotation angle A.

[0059] The arc length of the guide roller 26 corresponding to the rotation angle A can be expressed as (circumference length) × (ratio of rotation angle A to one rotation) using the circumference length of the guide roller 26. The circumference length can be expressed as πR using the diameter R (diameter dimension) of the guide roller 26. Note that π represents the pi, and the diameter R (diameter dimension) of the guide roller 26 indicates the diameter dimension (inner diameter) of the wire groove 26a.

[0060] The ratio of the rotation angle A to one rotation (360° in degree measure, 2π in radian measure) is (A / 2π) in radian measure. Therefore, the magnitude of the feed length L can be expressed as L = πR×(A / 2π) = RA / 2 using the rotation angle A in radian measure.

[0061] And the magnitude of the rotation angle A in radian measure can be obtained by calculating the ratio of the increase in the output signal before and after the measurement interval Δt elapses to the entire fluctuation range of the output signal. The increase in the output signal is obtained by (output signal at time t1 - output signal at time t0). The entire fluctuation range of the output signal is obtained by (upper limit value of the output signal - lower limit value of the output signal). Thus, A = (output signal at time t1 - output signal at time t0) / (upper limit value of the output signal - lower limit value of the output signal). For example, if the upper limit value of the output signal is 10V and the lower limit value is 0V, the value of the entire fluctuation range is 10V, so A = (output signal at time t1 - output signal at time t0) / 10.

[0062] However, when the reference posture is included in the posture taken by the guide roller 26 during the measurement interval Δt (when the rotation angle A straddles 359° to 0° in degree measure), the output signal at time t1 becomes smaller than the output signal at time t0. In that case, the magnitude of the rotation angle A during the measurement interval Δt can be calculated by correcting by adding the value of the entire fluctuation range to the increase in the output signal (which becomes a negative value). That is, when (output signal at time t1) < (output signal at time t0), A = (output signal at time t1 - output signal at time t0 + entire fluctuation range) / entire fluctuation range.

[0063] From the above, when expressing the feed length L again, When (the output signal at time t1) > (the output signal at time t0): L = (1 / 2) × R × (increase in the output signal) / (total fluctuation range)

[0064] When (the output signal at time t1) < (the output signal at time t0): L = (1 / 2) × R × (increase in the output signal + total fluctuation range) / (total fluctuation range) That is.

[0065] And, since the wire 21 with a feed length L is fed during the measurement interval Δt, the feed speed of the wire 21 (the length of the wire 21 fed per unit time) is represented by L / Δt. Using these relational expressions, the arithmetic unit 40 can calculate the feed speed of the wire 21 based on the difference in the output signal for each measurement interval Δt (the increase in the output signal from time t0 to time t1), the value of the measurement interval Δt, and the diameter dimension (diameter R) of the guide roller 26.

[0066] Also, the arithmetic unit 40 can calculate the feed amount of the wire 21 based on the calculated feed speed. Since the feed amount of the wire 21 corresponds to the weight of the consumed wire 21, it can be obtained by calculating the weight for the feed length L of the wire 21. The weight for the feed length L of the wire 21 can be calculated by (feed length L) × (cross-sectional area of the wire 21) × (specific gravity of the wire 21).

[0067] The cross-sectional area of the wire 21 can be calculated using the diameter D (diameter dimension) of the wire 21 as π × (D / 2) 2 Since it can be calculated in this way, (feed amount) = (π / 4) × (feed length L) × D 2 × (specific gravity of the wire 21).

[0068] Expressing this in terms of the feed speed, (feed amount) = (π / 4) × (feed speed) × (measurement interval Δt) × D 2 × (specific gravity of the wire 21). In the above manner, the arithmetic unit 40 can calculate the feed amount of the wire 21 based on the supply speed, the diameter dimension (diameter D) of the wire 21, and the specific gravity of the wire 21.

[0069] According to the wire feeding amount measuring device 30 of the present embodiment, since no magnetic field is directly applied to the wire 21, the wire 21 is not magnetized along with the measurement of the feeding amount of the wire 21. Therefore, the wire feeding amount measuring device 30 and the wire feeding amount measuring method using the same can measure the feeding amount of the wire 21 without affecting the wire 21. Further, since the feeding amount of the wire 21 is measured using the magnetic sensor 32, unlike the measurement using an optical sensor, the measurement result is not affected by the arc light generated during welding. Also, the possibility that the measurement result is affected by dust, oil, etc. adhering to the wire feeding amount measuring device 30 and becomes unstable is reduced.

[0070] In addition, since the object to be directly measured is the guide roller 26 instead of the wire 21, components such as the magnetic sensor 32 for measurement can be arranged at positions away from the wire 21. Therefore, in the measurement using the wire feeding amount measuring device 30, it is not necessary to disassemble the wire feeding device 20 for measuring the feeding amount of the wire 21, and the wire feeding amount measuring device 30 including components such as the magnetic sensor 32 can be easily attached to and detached from the wire feeding device 20. Further, since the wire feeding amount measuring device 30 of the present embodiment can adjust the interval between the mounting blocks 34 and the mounting position of the magnetic sensor 32, it can be attached to any wire feeding device 20. In the above embodiment, the wire feeding amount measuring device 30 is attached to the wire feeding device 20 by attaching the mounting block 34 to the base member 25 with the adsorption magnet 34b. However, the method of attaching the wire feeding amount measuring device 30 to the wire feeding device 20 is not limited to this and can be selected according to the application. For example, the wire feeding amount measuring device 30 may be attached to the wire feeding device 20 by adsorption with a vacuum pad. Also, a method of attaching the wire feeding amount measuring device 30 to the wire feeding device 20 by screwing by screw processing, clamping by a gripping mechanism, etc. may be selected. Further, when the movement of the wire feeding amount measuring device 30 is not required, the wire feeding amount measuring device 30 may be joined to the wire feeding device 20 by welding or the like.

Explanation of Reference Numerals

[0071] 10 Welding system 11 Welding base material 13 Welding torch 14 Base material side cable 18 Torch side cable 20 Wire feeding device 21 Wire 22 Reel 23 Straightening roller 24 Pressing roller 25 Base member 25a Base column part 26 Guide roller 26a Groove for wire 27 Nut for guide roller 28 Wire guiding path 30 Wire feeding amount measuring device 31 Frame member 31a Block interval adjusting groove 31b Sensor position adjusting groove 32 Magnetic sensor 32a Detection surface 32b Threaded hole 34 Mounting block 34a Detachable dial 34b Adsorbing magnet 36 Block fixing plate 36a Block fixing screw 37 Sensor mounting screw 39 Detection part 40 Calculation part 41 Sensor communication line 50 Bracket member 51 Bracket recess 52 Circumferential threaded hole 52a Bracket mounting screw 53 Axial threaded hole 54 Bracket convex part 60 Magnetic position marker 63 Threaded hole 64 Marker recess 65 Marker mounting screw 66 Marker magnet 67 Marking

Claims

1. A wire feed rate measuring device attached to a wire feeding device having a guide roller for guiding a wire used for welding, for measuring a feed rate of the wire from the wire feeding device, a magnetic position marker attached to the guide roller and rotating together with the guide roller, and a magnetic sensor that outputs an output signal corresponding to a rotation angle of the guide roller and the magnetic position marker, wherein the wire feed rate measuring device measures a feed rate of the wire based on the output signal of the magnetic sensor.

2. further comprising a bracket member attached to the guide roller and rotating together with the guide roller, wherein the magnetic position marker is attached to the guide roller via the bracket member, and the wire feed rate measuring device according to claim 1.

3. further comprising two mounting blocks and a frame member, wherein when the wire feeding device has a base member including two base column portions and the guide roller is disposed between the two base column portions, each of the two mounting blocks includes an adsorption magnet capable of switching between a state of being adsorbed to the base column portion by magnetic force and a state of not being adsorbed to the base column portion, the two mounting blocks are attached to the frame member with a space corresponding to a distance between the two base column portions therebetween, the magnetic sensor is attached to the frame member between the two mounting blocks, each of the two mounting blocks adsorbs to the base column portion by the adsorption magnet, whereby the frame member is attached to the wire feeding device, and when the frame member is attached to the wire feeding device, the magnetic sensor faces the magnetic position marker attached to the guide roller, and the wire feed rate measuring device according to claim 1.

4. The wire feed rate measuring device according to claim 3, wherein the magnetic sensor is capable of changing an attachment position with respect to the frame member.

5. The wire feed rate measuring device according to claim 3, wherein each of the two mounting blocks is capable of changing an attachment position with respect to the frame member to adjust a distance between the two mounting blocks.

6. further comprising an arithmetic unit that calculates a feed rate of the wire based on the output signal from the magnetic sensor, The calculation unit receives the output signal corresponding to the rotation angle of the guide roller from the magnetic sensor at each specified measurement interval. The calculation unit calculates the feeding speed at which the wire is fed based on the difference between the output signals at each measurement interval, the measurement interval, and the diameter dimension of the guide roller. The calculation unit calculates the feeding amount of the wire based on the calculated feeding speed. The wire feeding amount measuring device according to claim 1.

7. The calculation unit calculates the feeding amount of the wire based on the feeding speed, the diameter dimension of the wire, and the specific gravity of the wire. The wire feeding amount measuring device according to claim 6.

8. A wire feeding amount measuring device that measures the feeding amount of a wire from a wire feeding device having a guide roller that guides the wire used for welding, a magnetic position marker attached to the guide roller and rotating together with the guide roller, and a magnetic sensor that outputs an output signal corresponding to the rotation angle of the magnetic position marker, and a wire feeding amount measuring method for measuring the feeding amount of the wire based on the output signal of the magnetic sensor.

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