CONDITION MONITORING SYSTEM FOR WIRESAW, WIRESAW AND CONDITION MONITORING METHOD FOR WIRESAW

Abstract

A condition monitoring system for a wire saw, comprising a first processing roller and a second processing roller, a wire stretched over the first and second processing rollers, and a motion element that moves to press a workpiece against the wire between the first and second processing rollers while the wire is running, includes a measurement data acquisition unit configured to acquire measurement data from a first wire sensor detecting the quantity of wire fed into the first processing roller and measurement data from a second wire sensor detecting the quantity of wire fed out of the second processing roller, an estimation unit configured to estimate the condition of the wire based on the quantity fed and the quantity discharged, and an output unit configured to output an estimation result from the estimation unit.

Description

TECHNICAL AREA

[0001] The present disclosure relates to a condition monitoring system for a wire saw, a wire saw and a condition monitoring method for a wire saw. STATE OF THE ART

[0002] In a technical field relating to a wire saw, a wire bending monitoring system as known in patent literature 1 is disclosed. LIST OF COUNTERPOINTS Patent Literature

[0003] Patent Literature 1: JP 2014-060397 A BRIEF DESCRIPTION OF THE INVENTION Technical Problem

[0004] When a wire saw performs a cutting operation, a workpiece is pressed against a moving wire. If the workpiece is cut by the wire in a defective condition, there is a possibility that the quality of the workpiece will be degraded after cutting or that the productivity of the wire saw will be reduced.

[0005] One function of the present disclosure is to monitor the condition of a wire. Solution to the problem

[0006] According to the present disclosure, a condition monitoring system for a wire saw is provided, including a first processing roller and a second processing roller, a wire stretched over the first processing roller and the second processing roller, and a motion element that moves such that, with the wire running, it presses a workpiece against the wire between the first processing roller and the second processing roller, wherein the condition monitoring system includes a measurement data acquisition unit configured to acquire measurement data from a first wire sensor that detects a quantity of wire fed into the first processing roller and measurement data from a second wire sensor that detects a quantity of wire discharged from the second processing roller, an estimation unit configured to estimate a condition of the wire based on the quantity fed and the quantity discharged, and an output unit.which is configured to output an estimate result by the estimation unit. Advantageous effects of the invention

[0007] According to the present disclosure, the condition of a wire can be monitored. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a schematic illustration of a wire saw according to one embodiment. Fig. Figure 2 is a block diagram illustrating the wire saw according to the embodiment. Fig. Figure 3 is a block diagram illustrating a condition monitoring system for the wire saw according to the embodiment. Fig. Figure 4 is a diagram describing the operation of the wire saw according to the embodiment. Fig. Figure 5 is a diagram to describe a relationship between a condition of the wire and an extent of deflection according to the embodiment. Fig. Figure 6 is a diagram describing the relationship between the condition of the wire and the extent of the deflection according to the embodiment. Fig. Figure 7 is a diagram to describe a difference between a quantity of wire supplied and a quantity of wire discharged according to the embodiment. Fig. Figure 8 is a flowchart illustrating a condition monitoring procedure for the working machine according to the embodiment. Fig. Figure 9 is a block diagram illustrating a computer system according to the embodiment. Fig. Figure 10 is a diagram illustrating part of a wire saw according to a further embodiment. DESCRIPTION OF EXECUTION FORMS

[0008] The following describes embodiments according to the present disclosure with reference to the drawings; however, the disclosure is not limited to these embodiments. Components of the embodiments described below can be combined in any way. In some cases, certain components are not used. Wire saw

[0009] Fig. Figure 1 is a diagram that schematically illustrates a wire saw 1 according to one embodiment. Fig. Figure 2 is a block diagram illustrating the wire saw 1 according to the embodiment. The wire saw 1 cuts a workpiece W. Examples of the workpiece W include a silicon ingot, synthetic quartz, crystal, and a magnet.

[0010] As in Fig. 1 and Fig. As illustrated in Figure 2, the wire saw 1 includes a processing roller 2, a roller motor 3, a wire 4, a movement element 5, a coil body 6, a coil motor 7, a traversing device 8, a dancer roller 9, a dancer motor 10, a guide roller 11, a wire sensor 12 and a control unit 13.

[0011] The processing roller 2 rotates while supporting the wire 4. A plurality of parallel grooves are provided on one surface of the processing roller 2. At least a portion of the wire 4 is positioned within the groove.

[0012] At least two processing roller 2 units are provided. In this embodiment, two processing roller 2 units are provided. Processing roller 2 includes a processing roller 2A and a processing roller 2B. It should be noted that three or four processing roller 2 units may be provided.

[0013] The roller motor 3 generates a rotational force to rotate the processing roller 2. The roller motor 3 is connected to the processing roller 2. The processing roller 2 is rotated by the roller motor 3 in both a forward and a reverse direction. In this embodiment, the roller motor 3 includes a roller motor 3A, which is connected to the processing roller 2A, and a roller motor 3B, which is connected to the processing roller 2B. The processing roller 2A and the processing roller 2B rotate synchronously with each other in the forward or reverse direction.

[0014] The wire 4 is stretched over the processing roller 2A and the processing roller 2B. At least a portion of the wire 4 is positioned between the processing roller 2A and the processing roller 2B. By rotating the processing roller 2 in the forward direction, the wire 4 runs between an upper section of the processing roller 2A and an upper section of the processing roller 2B in one direction, from the processing roller 2A to the processing roller 2B. By rotating the processing roller 2 in the reverse direction, the wire 4 runs between the upper section of the processing roller 2A and the upper section of the processing roller 2B in the opposite direction, from the processing roller 2B to the processing roller 2A.

[0015] The wire 4 cuts the workpiece W. In this embodiment, the wire saw 1 cuts the workpiece W using a method with firmly bonded abrasive grains. The firmly bonded abrasive grain method is a method for cutting the workpiece W with the wire 4, which includes a core wire and abrasive grains attached to a surface of the core wire. The core wire of the wire 4 is made, for example, of carbon steel. Examples of abrasive grains include diamond abrasive grains. It should be noted that a loose grinding method can be used for the wire saw 1, in which the workpiece W is cut by the wire 4 while grinding slurry is fed to the running wire 4.

[0016] The moving element 5 moves in such a way that it presses the workpiece W against the wire 4 between the processing rollers 2A and 2B while the wire 4 is running. In this embodiment, the moving element 5 is arranged above the wire 4 between the processing rollers 2A and 2B. The moving element 5 is raised and lowered in a position in which it holds the workpiece W. The workpiece W is attached to a lower surface of the moving element 5. As the moving element 5 moves downwards, it presses the workpiece W, held by the moving element 5, against the wire 4, which runs between the upper section of the processing roller 2A and the upper section of the processing roller 2B. When the workpiece W is pressed against the running wire 4, it is cut by the wire 4.

[0017] The coil former 6 guides the wire 4 from its base and winds it onto the coil former. The wire 4 is wound around the coil former 6. Two coil formers 6 are provided. The coil former 6 encloses a coil former 6A and a coil former 6B. One end of the wire 4 is connected to coil former 6A. Another end of the wire 4 is connected to coil former 6B.

[0018] The coil motor 7 generates a torque to rotate the coil former 6. The coil motor 7 is connected to the coil former 6. In this embodiment, the coil motor 7 includes a coil motor 7A, which is connected to the coil former 6A, and a coil motor 7B, which is connected to the coil former 6B. The coil motor 7A and the coil motor 7B are alternately rotated synchronously in the forward or reverse direction.

[0019] When the processing roller 2 rotates in the forward direction, the coil former 6A rotates so that the wire 4 is discharged, and the coil former 6B rotates so that the wire 4 is wound onto it. The wire 4 discharged from coil former 6A is fed to the processing roller 2A. The wire 4 discharged from processing roller 2B is wound around the coil former 6B.

[0020] When the processing roller 2 rotates in the reverse direction, the coil former 6B rotates so that the wire 4 is discharged, and the coil former 6A rotates so that the wire 4 is wound onto it. The wire 4 discharged from the coil former 6B is fed to the processing roller 2B. The wire 4 discharged from the processing roller 2A is wound around the coil former 6A.

[0021] The traversing device 8 adjusts the position of the wire 4 wound around the coil former 6. Two units of the traversing device 8 are provided. The traversing device 8 comprises a traversing device 8A, which adjusts the position of the wire 4 wound around the coil former 6A, and a traversing device 8B, which adjusts the position of the wire 4 wound around the coil former 6B. The traversing device 8 includes a traversing roller 14, which is movable in an axial direction along the coil former 6 at a position opposite the coil former 6. The traversing roller 14 is moved in the axial direction along the coil former 6 by a driving force generated by a traversing actuator (not illustrated).

[0022] The traversing roller 14 adjusts the position of the wire 4 in the axial direction of the coil former 6 by moving in the axial direction of the coil 6. The traversing roller 14 is arranged between the processing roller 2 and the coil former 6. Two traversing roller 14 units are provided. The traversing roller 14 includes a traversing roller 14A, which is enclosed in the traversing device 8A, and a traversing roller 14B, which is enclosed in the traversing device 8B. The traversing roller 14A is arranged between the processing roller 2A and the coil former 6A. The traversing roller 14B is arranged between the processing roller 2B and the coil former 6B. The wire 4 is in contact with the traversing roller 14. The traversing roller 14 is a driven roller that rotates with the movement of the wire 4.

[0023] The dancer roller 9 adjusts the tension of the wire 4 by oscillation. The dancer roller 9 is rotatably supported by a distal end section of a dancer arm 15. The dancer roller 9 is arranged between the processing roller 2 and the coil former 6. The dancer roller 9 is arranged between the processing roller 2 and the traversing roller 14. Two units of the dancer roller 9 are provided. The dancer roller 9 includes a dancer roller 9A, which is arranged between the processing roller 2A and the coil former 6A, and a dancer roller 9B, which is arranged between the processing roller 2B and the coil former 6B. The dancer roller 9A is arranged between the processing roller 2A and the traversing roller 14A. The dancer roller 9B is arranged between the processing roller 2B and the traversing roller 14B. The wire 4 is in contact with the dancer roller 9. The dancer roller 9 is a driven roller that is rotated with the movement of the wire 4.

[0024] The dancer motor 10 generates a driving force to oscillate the dancer roller 9 via the dancer arm 15. The dancer motor 10 is connected to the dancer arm 15. In this embodiment, the dancer motor 10 includes a dancer motor 10A, which oscillates the dancer roller 9A, and a dancer motor 10B, which oscillates the dancer roller 9B. The tension of the wire 4 is adjusted by the dancer roller 9, which is oscillated by the driving force of the dancer motor 10.

[0025] The guide roller 11 guides the wire 4. The guide roller 11 is arranged between the processing roller 2 and the coil former 6. The guide roller 11 is arranged between the processing roller 2 and the dancer roller 9. At least two units of the guide roller 11 are provided. In this embodiment, the guide roller 11 includes a guide roller 11A, which is arranged between the processing roller 2A and the coil former 6A, and a guide roller 11B, which is arranged between the processing roller 2B and the coil former 6B. The guide roller 11A is arranged between the processing roller 2A and the dancer roller 9A. The guide roller 11B is arranged between the processing roller 2B and the dancer roller 9B. The wire 4 is in contact with the guide roller 11. The guide roller 11 is a driven roller that rotates with the movement of the wire 4.

[0026] It should be noted that any number of two or more units of the guide roller 11 can be provided. For example, four or six units of the guide roller 11 can be provided. Two or more units of the guide roller 11 can be arranged between the processing roller 2A and the dancer roller 9A. Two or more units of the guide roller 11 can be arranged between the processing roller 2B and the dancer roller 9B.

[0027] The wire sensor 12 detects the degree of movement of the wire 4. Two units of the wire sensor 12 are provided. The wire sensor 12 includes a wire sensor 12A, which detects the degree of movement of the wire 4 relative to the processing roller 2A, and a wire sensor 12B, which detects the degree of movement of the wire 4 relative to the processing roller 2B.

[0028] When processing roller 2 moves in the forward direction of rotation, wire sensor 12A detects a quantity of wire 4 fed into processing roller 2A. When processing roller 2 moves in the forward direction of rotation, wire sensor 12B detects a quantity of wire 4 being discharged from processing roller 2B.

[0029] When processing roller 2 moves in the reverse direction of rotation, wire sensor 12B detects a quantity of wire 4 fed into processing roller 2B. When processing roller 2 moves in the reverse direction of rotation, wire sensor 12A detects a quantity of wire 4 being discharged from processing roller 2A.

[0030] The quantity of wire 4 fed into processing roller 2 refers to the extent of movement of the wire 4 entering the rotating processing roller 2. The quantity of wire 4 discharged from processing roller 2 refers to the extent of movement of the wire 4 discharged from the rotating processing roller 2. The extent of movement of the wire 4 can be the extent of movement of the wire 4 per unit of time. The extent of movement of the wire 4 can be the extent of movement of the wire 4 in a third state described below.

[0031] In this embodiment, the wire sensor 12 includes a rotary encoder capable of detecting the number of revolutions of the guide roller 11. As described above, the guide roller 11 is a driven roller that rotates with the movement of the wire 4. The range of motion of the wire 4 and the number of revolutions of the guide roller 11 correspond to each other in a one-to-one ratio. Increasing the number of revolutions of the guide roller 11 increases the range of motion of the wire 4, and decreasing the number of revolutions of the guide roller 11 decreases the range of motion of the wire 4. The wire sensor 12 detects the range of motion of the wire 4 by detecting the number of revolutions of the guide roller 11. The number of revolutions of the guide roller 11 can be the number of revolutions per unit of time.The number of revolutions of the guide roller 11 can be the number of revolutions of the guide roller 11 in the third state described below.

[0032] The wire sensor 12 can be a magnetic encoder or an optical encoder. If the wire sensor 12 is a magnetic encoder, the guide roller 11 is equipped with a permanent magnet. The wire sensor 12 detects the number of revolutions of the guide roller 11 by detecting a magnetic field that changes due to the rotation of the guide roller 11.

[0033] When processing roller 2 moves in the forward direction of rotation, wire sensor 12A detects the number of revolutions of guide roller 11A as the amount of wire 4 fed into processing roller 2A. When processing roller 2 moves in the forward direction of rotation, wire sensor 12B detects the number of revolutions of guide roller 11B as the amount of wire 4 fed from processing roller 2B.

[0034] When processing roller 2 moves in the reverse direction, wire sensor 12B detects the number of revolutions of guide roller 11B as the amount of wire 4 fed into processing roller 2B. When processing roller 2 moves in the reverse direction, wire sensor 12A detects the number of revolutions of guide roller 11A as the amount of wire 4 fed from processing roller 2A.

[0035] Control unit 13 controls wire saw 1. Control unit 13 includes a computer system that includes at least one processor. Condition monitoring system

[0036] Fig. Figure 3 is a block diagram illustrating a condition monitoring system 20 for the wire saw 1 according to the embodiment. The condition monitoring system 20 monitors at least one condition of the wire 4. The condition monitoring system 20 estimates the condition of the wire 4 based on measurement data from the wire sensor 12. The condition of the wire 4 includes the degree of deflection of the wire 4 between the processing roller 2A and the processing roller 2B.

[0037] The condition monitoring system 20 includes the wire sensor 12, a processing device 21, and an output device 22. The processing device 21 performs an arithmetic operation. The processing device 21 includes a computer system that includes at least one processor. The output device 22 outputs an operating result from the processing device 21. The output device 22 includes an output device capable of displaying data. Note that the output device 22 may include an audio output device capable of emitting audio data. Note that the output device 22 may output a control signal for controlling the wire saw 1 based on the operating result of the processing device 21.

[0038] The processing device 21 includes a measurement data acquisition unit 23, an estimation unit 24 and an output unit 25.

[0039] The data acquisition unit 23 acquires measurement data from wire sensor 12A and wire sensor 12B. When the processing roller 2 rotates in the forward direction, the measurement data from wire sensor 12A indicates the quantity of wire 4 fed into processing roller 2A, and the measurement data from wire sensor 12B indicates the quantity of wire 4 discharged from processing roller 2B. When the processing roller 2 rotates in the reverse direction, the measurement data from wire sensor 12B indicates the quantity of wire 4 fed into processing roller 2B, and the measurement data from wire sensor 12A indicates the quantity of wire 4 discharged from processing roller 2A.

[0040] Estimating unit 24 estimates the condition of the wire 4 based on the quantity of wire 4 supplied and the quantity of wire 4 discharged. In this embodiment, estimating unit 24 estimates the condition of the wire 4 based on the difference between the quantity of wire 4 supplied and the quantity of wire 4 discharged. Estimating unit 24 estimates the extent of the deflection of the wire 4 between processing roller 2A and processing roller 2B as the condition of the wire 4. Estimating unit 24 estimates the condition of the wire 4 during the processing of the workpiece W.

[0041] Output unit 25 outputs an estimation result from estimation unit 24. Output unit 25 outputs the extent of wire 4 deflection estimated by estimation unit 24. Output unit 25 causes output device 22 to output the estimation result from estimation unit 24. Output unit 25 can output a control signal to control wire saw 1 based on the extent of wire 4 deflection estimated by estimation unit 24. Estimation of wire condition

[0042] Next, a method for estimating the condition of the wire 4 according to the embodiment is described. In the following description, it is assumed that the processing roller 2 rotates in the forward direction.

[0043] Fig. Figure 4 is a diagram describing the operation of the wire saw 1 according to the embodiment. When the workpiece W is cut by the wire 4, the control unit 13 drives the roller motor 3 and the spool motor 7 to run the wire 4. The control unit 13 controls the motion element 5 so that the workpiece W changes from a first state to a third state via a second state while the wire 4 is running. The motion element 5 moves downwards at a predetermined speed. The motion element 5 can move downwards at a constant speed or it can move downwards while changing its speed incrementally.

[0044] The first state is a state in which the workpiece W is separated from the wire 4. In the first state, the workpiece W, held by the moving element 5, is positioned above the wire 4 between the processing roller 2A and the processing roller 2B. In the first state, the wire 4 is not bent between the processing roller 2A and the processing roller 2B.

[0045] The second state is the state at the moment when the workpiece W, moving towards the wire 4, comes into contact with it. The downward-moving motion element 5, which holds the workpiece W and moves towards the wire 4, causes the workpiece W to transition from the first state to the second state. In the second state, the workpiece W is in contact with the wire 4 between the upper section of the processing roller 2A and the upper section of the processing roller 2B. In the second state, the wire 4 is not bent between the processing rollers 2A and 2B.

[0046] The third state is a state in which the workpiece W moves in contact with the wire 4 in such a way that it bends the wire 4. After the workpiece W comes into contact with the wire 4, the workpiece W transitions from the second state to the third state due to the further downward movement of the moving element 5. In the third state, the wire 4 is bent downwards between the upper section of the processing roller 2A and the upper section of the processing roller 2B. In the third state, the wire 4 is gradually bent between the processing roller 2A and the processing roller 2B as the workpiece W moves downwards. In the third state, the degree of bending of the wire 4 gradually increases with the downward movement of the workpiece W.

[0047] As the degree of deflection of wire 4 gradually increases, the change in deflection decreases when the contact force of the workpiece W against the wire 4 reaches a certain value and cutting of the workpiece W begins. That is, when cutting of the workpiece W begins, the degree of deflection of wire 4 changes from a variable state to a constant state.

[0048] In the first state and in the second state, the amount of wire 4 fed into the processing roller 2A and the amount of wire 4 removed from the processing roller 2B are equal to each other.

[0049] In the third state, the degree of deflection of the wire 4 changes between the processing roller 2A and the processing roller 2B, and therefore the amount of wire 4 discharged from processing roller 2B is less than the amount of wire 4 fed into processing roller 2A. During a period in which the degree of deflection of the wire 4 gradually increases due to the movement of the workpiece W after the workpiece W has come into contact with the wire 4, the amount of wire 4 discharged from processing roller 2B is less than the amount of wire 4 fed into processing roller 2A. Since the amount of wire 4 discharged from processing roller 2B is less than the amount of wire 4 fed into processing roller 2A, the number of revolutions of guide roller 11B is reduced.

[0050] When the contact force of the workpiece W against the wire 4 reaches a certain value and the cutting of the workpiece W begins, the amount of wire 4 discharged from the processing roller 2B approaches the amount of wire 4 fed into the processing roller 2A. That is, when the degree of deflection of the wire 4 reaches a constant state, the amount of wire 4 fed into the processing roller 2A and the amount of wire 4 discharged from the processing roller 2B essentially equalize.

[0051] This means that in the third state, where the degree of deflection of wire 4 is in the unstable state, a difference arises between the quantity of wire 4 supplied and the quantity of wire 4 removed due to the change in the degree of deflection. The difference between the quantity supplied and the quantity removed increases when the degree of deflection of wire 4 increases, when the degree of deflection changes from the unstable state to the stable state, and the difference between the quantity supplied and the quantity removed decreases when the degree of deflection decreases.

[0052] Fig. 5 and Fig. Figure 6 are diagrams to describe a relationship between the condition of the wire 4 and the extent of the deflection according to the embodiment. Fig. Figure 5 illustrates the extent of the deflection of wire 4 when the condition of wire 4 is good. Fig. Figure 6 illustrates the extent of the deflection of wire 4 when the condition of wire 4 is faulty.

[0053] The good condition of wire 4 means that wire 4 is in a state where it is likely to cut workpiece W. For example, wire 4 will cut workpiece W easily if it is new or if the abrasive grains adhere sufficiently to the surface of the core wire of wire 4.

[0054] The defective condition of wire 4 means that wire 4 is in a state where it is unlikely to cut workpiece W. For example, wire 4 is unlikely to cut workpiece W if it is in a state where it has deteriorated due to use, or if the abrasive grains do not adhere sufficiently to the surface of the core wire of wire 4.

[0055] As in Fig. As illustrated in Figure 5, if the condition of the wire 4 is good, cutting of the workpiece W will begin even if the contact force of the workpiece W against the wire 4 is low in the third state. That is, since the sharp wire 4 is used, cutting of the workpiece W will only begin with slight pressure of the workpiece W against the wire 4. Therefore, as shown in Figure 5, Fig. Figure 5 illustrates that if the condition of the wire 4 is good, the extent of the deflection of the wire 4 when the workpiece W is cut through the wire 4 is small.

[0056] As in Fig. As illustrated in Figure 6, if the wire 4 is in a faulty state, it is necessary to increase the contact force of the workpiece W against the wire 4 in order to cut the workpiece W in the third state. That is, since the blunt wire 4 is used, the workpiece W must be pressed firmly against the wire 4 to begin cutting the workpiece W. Therefore, as shown in Fig. Figure 6 illustrates that if the condition of the wire 4 is faulty, the extent of the deflection of the wire 4 will be large when the workpiece W is cut through the wire 4.

[0057] As described above, in the third state, the difference between the amount of wire 4 fed into processing roller 2A and the amount of wire 4 discharged from processing roller 2B is greater when the wire 4 deflects more, and the difference between the amount of wire 4 fed into processing roller 2A and the amount of wire 4 discharged from processing roller 2B is smaller when the wire 4 deflects less. Therefore, the estimating unit 24 can estimate the condition of the wire 4 based on the difference between the amount of wire 4 fed into and the amount of wire 4 discharged, as detected by the wire sensor 12 in the third state. If the difference between the amount of wire 4 fed into and the amount of wire 4 discharged is large, the estimating unit 24 can estimate that the condition of the wire 4 is faulty.If the difference between the amount of wire 4 supplied and the amount of wire 4 removed is small, the estimating unit 24 can estimate that the condition of the wire 4 is good.

[0058] Fig. Figure 7 is a diagram describing the difference between the quantity of wire 4 supplied and the quantity of wire 4 discharged according to the embodiment. In the diagram shown in Fig. In diagram 7, a horizontal axis represents the elapsed time from the start time of cutting the workpiece W. A vertical axis represents the difference between the quantity of wire 4 supplied and the quantity of wire 4 discharged. The quantity of wire 4 supplied is detected by wire sensor 12A, and the quantity of wire 4 discharged is detected by wire sensor 12B. The start time of cutting is a point in time at which the workpiece W is in the first state.

[0059] In Fig. Line 7 La indicates a relationship between the difference between the amount of wire 4 supplied and the amount of wire 4 removed, and the elapsed time, when the cutting is performed using wire 4 in good condition. Line Lb indicates the relationship between the difference between the amount of wire 4 supplied and the amount of wire 4 removed, and the elapsed time, when the cutting is performed using wire 4 in a defective condition.

[0060] As in Fig. As shown in Figure 7, when the workpiece W is in the first state, the quantity of wire 4 fed into the processing roller 2A and the quantity of wire 4 removed from the processing roller 2B are equal to each other, and therefore the difference between the quantity of wire 4 fed in and the quantity of wire 4 removed is zero.

[0061] In Fig. 7 is a time t1, a time at which the workpiece W changes from the first state to the second state. After the workpiece W changes from the first state to the second state, the workpiece W moves downwards, so that the wire 4 is bent, which gradually increases the difference between the amount of wire 4 supplied and the amount of wire 4 removed after time t1.

[0062] The maximum difference between the amount of wire 4 supplied and the amount of wire 4 discharged when wire 4 is in good condition is a value Da. The maximum difference between the amount of wire 4 supplied and the amount of wire 4 discharged when wire 4 is defective is a value Db. The value Db is greater than the value Da. That is, when wire 4 is in good condition, the difference between the amount of wire 4 supplied and the amount of wire 4 discharged in the third state is small. When wire 4 is defective, the difference between the amount of wire 4 supplied and the amount of wire 4 discharged in the third state is large.

[0063] The difference between the quantity of wire 4 fed in and the quantity of wire 4 discharged corresponds to the degree of deflection of the wire 4 in a one-to-one ratio. The data acquisition unit 23 acquires, at least in the third state, the measurement data of wire sensor 12A, which detects the quantity of wire 4 fed into processing roller 2A, and the measurement data of wire sensor 12B, which detects the quantity of wire 4 discharged from processing roller 2B. The estimation unit 24 can estimate the state of the wire 4 based on the difference between the quantity of wire 4 fed in and the quantity of wire 4 discharged, as detected by the data acquisition unit 23 in the third state. The estimation unit 24 can estimate that the condition of the wire 4 is good if the difference between the amount of wire 4 supplied in the third state and the amount of wire 4 removed in the third state is small.The estimation unit 24 can estimate that the state of wire 4 is faulty if the difference between the amount of wire 4 supplied in the third state and the amount of wire 4 removed in the third state is large.

[0064] It should be noted that the degree of deflection of wire 4 can change depending on the processing condition for the workpiece W. For example, if the decreasing speed of the moving element 5 is increased to cut the workpiece W in a short time, the degree of deflection of wire 4 will increase in the third state, even if the condition of wire 4 is otherwise good. If the condition of wire 4 is estimated based on the maximum value of the difference between the amount of wire 4 fed in and the amount of wire 4 discharged, it is necessary to set the same processing condition (the decreasing speed of the moving element 5) for the workpiece W when estimating the condition of wire 4. Condition monitoring procedures

[0065] Fig. Figure 8 is a flowchart illustrating a state monitoring procedure for the wire saw 1 according to the embodiment. When the workpiece W is cut by the wire 4, the control unit 13 drives the roller motor 3 and the spool motor 7 to run the wire 4. The control unit 13 controls the motion element 5 so that the workpiece W transitions from the first state to the third state via the second state while the wire 4 is running.

[0066] The wire sensor 12A detects the number of revolutions of the guide roller 11A. The wire sensor 12B detects the number of revolutions of the guide roller 11B. The measurement data acquisition unit 23 acquires measurement data from the wire sensor 12A and measurement data from the wire sensor 12B (step S1).

[0067] The estimation unit 24 calculates a difference between the number of revolutions of guide roller 11A and the number of revolutions of guide roller 11B based on the measurement data acquired in step S1. By calculating the difference between the number of revolutions of guide roller 11A and the number of revolutions of guide roller 11B, a difference is calculated between the quantity of wire 4 fed into processing roller 2A and the quantity of wire 4 discharged from processing roller 2B (step S2).

[0068] The estimation unit 24 estimates the extent of the deflection of the wire 4 between the processing roller 2A and the processing roller 2B based on the difference between the quantity of wire 4 supplied calculated in step S2 and the quantity of wire 4 discharged (step S3).

[0069] The output unit 25 causes the output device 22 to output an estimated degree of deflection, which is an estimated value of the degree of deflection estimated in step S3 (step S4).

[0070] An operator or manager of the wire saw 1 can determine the condition of the wire 4 by checking the estimated degree of deflection output by the output device 22. If the estimated degree of deflection is small, the operator or manager of the wire saw 1 can determine that the condition of the wire 4 is good. If the estimated degree of deflection is large, the operator or manager of the wire saw 1 can determine that the condition of the wire 4 is defective. For example, if the estimated degree of deflection is less than a predetermined degree of deflection, the operator or manager of the wire saw 1 can determine that the condition of the wire 4 is good. For example, if the estimated degree of deflection is greater than a predetermined degree of deflection, the operator or manager of the wire saw 1 can determine that the condition of the wire 4 is defective.

[0071] It should be noted that in step S4, output unit 25 can output a control signal to control wire saw 1 based on the estimated degree of deflection. For example, if the condition of wire 4 is faulty, output unit 25 can output a control signal to change a condition for processing by wire saw 1 or to stop the operation of wire saw 1. For example, if the estimated degree of deflection is greater than the predetermined degree of deflection, output unit 25 can output a control signal to reduce the downward speed of moving element 5 or to stop the movement of moving element 5. If the estimated degree of deflection is less than the predetermined degree of deflection, output unit 25 can output a control signal to increase the downward speed of moving element 5. computer system

[0072] Fig. Figure 9 is a block diagram illustrating a computer system 1000 according to the embodiment. Each of the control unit 13 and processing unit 21 described above is included in the computer system 1000. The computer system 1000 includes a processor 1001, such as a central processing unit (CPU), main memory 1002, which includes non-volatile memory such as read-only memory (ROM) and volatile memory such as random-access memory (RAM), memory 1003, and an interface 1004, which includes an input / output circuit. Functions of each of the control unit 13 and the processing unit 21 described above are stored as a computer program in memory 1003. The processor 1001 reads the computer program from memory 1003, loads the computer program into main memory 1002, and performs the processing described above according to the program.It should be noted that the computer program can be distributed to computer system 1000 via a network.

[0073] The computer program or computer system 1000 can perform the following according to the embodiment described above: detecting a quantity of wire 4 fed into the processing roller 2A by the wire sensor 12A, detecting a quantity of wire 4 discharged from the processing roller 2B by the wire sensor 12B, estimating a state of the wire 4 based on a difference between the quantity of wire 4 fed in detected by the wire sensor 12A and the quantity of wire 4 discharged detected by the wire sensor 12B, and outputting an estimation result. Effects

[0074] As described above, according to the embodiment, the condition monitoring system 20 can monitor the condition of the wire 4 based on the difference between the quantity of wire 4 fed into the processing roller 2A and the quantity of wire 4 discharged from the processing roller 2B. If it is determined that the condition of the wire 4 is defective, a measure such as replacing the wire 4 is taken, thereby preventing a reduction in the quality of the workpiece W after cutting or a reduction in the productivity of the wire saw 1.

[0075] The condition of the wire 4 includes the degree of deflection of the wire 4. For example, if the degree of deflection of the wire 4 is detected by a displacement sensor, it may be difficult to install the displacement sensor in a position opposite the wire 4 between the processing roller 2A and the processing roller 2B, or the installation of the displacement sensor may be time-consuming. In this embodiment, the wire sensor 12 can be easily installed in a position away from the processing roller 2A and the processing roller 2B. Further embodiment

[0076] In the embodiment described above, the wire sensor 12 detects the number of revolutions of the guide roller 11. The wire sensor 12 can detect the number of revolutions of the dancer roller 9 or the number of revolutions of the traversing roller 14.

[0077] Fig. Figure 10 is a diagram illustrating part of the wire saw 1 according to a further embodiment. In the embodiment described above, the wire sensor 12 detects the number of revolutions of a driven roller, such as the guide roller 11. As in Fig. As illustrated in Figure 10, the wire sensor 16 can include a detection device capable of detecting the running speed of the wire 4. The detection device can be a laser device. In the figure shown in Fig.In the illustrated example 10, when the processing roller 2 rotates in the forward direction, the wire sensor 16 includes a wire sensor 16A, which detects the running speed of the wire 4 entering the processing roller 2A, and a wire sensor 16B, which detects the running speed of the wire 4 exiting the processing roller 2B. The wire sensor 16A is arranged between the guide roller 11A and the processing roller 2A and detects the running speed of the wire 4 running from the guide roller 11A to the processing roller 2A. The wire sensor 16B is arranged between the processing roller 2B and the guide roller 11B and detects the running speed of the wire 4 running from the processing roller 2B to the guide roller 11B.Estimation unit 24 can estimate the condition of the wire 4 based on the difference between the running speed of the wire 4 entering processing roller 2A and the running speed of the wire 4 discharged from processing roller 2B. Furthermore, estimation unit 24 can estimate the quantity of wire 4 fed into processing roller 2A and the quantity of wire 4 discharged from processing roller 2B based on the running speed of the wire 4.

[0078] In the embodiment described above, the wire saw 1 can include the condition monitoring system 20. The control unit 13 and the processing device 21 can be configured with a single piece of hardware. The condition monitoring system 20 can include a network that is connected to either the wire saw 1 or the control unit 13. Reference symbol list

[0079] 1 Wire saw, 2 Processing roller, 2A Processing roller, 2B Processing roller, 3 Roller motor, 3A Roller motor, 3B Roller motor, 4 Wire, 5 Motion element, 6 Spool body, 6A Spool body, 6B Spool body, 7 Spool motor, 7A Spool motor, 7B Spool motor, 8 Traversing device, 8A Traversing device, 8B Traversing device, 9 Dancer roller, 9A Dancer roller, 9B Dancer roller, 10 Dancer motor, 10A Dancer motor, 10B Dancer motor, 11 Guide roller, 11A Guide roller, 11B Guide roller, 12 Wire sensor, 12A Wire sensor, 12B Wire sensor, 13 Control unit, 14 Traversing roller, 14A Traversing roller, 14B Traversing roller, 15 Dancer arm, 16 Wire sensor, 16A Wire sensor, 16B Wire sensor, 20 Condition monitoring system, 21 Processing device, 22 Output device, 23 Measurement data acquisition unit, 24 Estimation unit, 25 Output unit, 1000 Computer system, 1001 Processor, 1002 Main memory, 1003 Storage, 1004 Interface, W Workpiece QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2014-060397 A

[0003]

Claims

Condition monitoring system for a wire saw, including a first processing roller and a second processing roller, a wire stretched over the first processing roller and the second processing roller, and a motion element that moves to press a workpiece against the wire between the first processing roller and the second processing roller while the wire is running; the condition monitoring system comprising: a measurement data acquisition unit configured to acquire measurement data from a first wire sensor that detects a quantity of wire fed into the first processing roller, and measurement data from a second wire sensor that detects a quantity of wire discharged from the second processing roller; an estimation unit configured to estimate a condition of the wire based on the quantity fed and the quantity discharged; and an output unit configured to output an estimate result through the estimation unit. Condition monitoring system for the wire saw according to claim 1, wherein the estimating unit estimates the condition of the wire based on a difference between the quantity supplied and the quantity discharged. Condition monitoring system for the wire saw according to claim 1, wherein the condition of the wire includes an extent of the deflection of the wire between the first processing roller and the second processing roller. Condition monitoring system for the wire saw according to claim 1, wherein the estimating unit estimates the condition of the wire during processing of the workpiece. Condition monitoring system for the wire saw according to claim 4, wherein the movement element is controlled to change from a first state in which the workpiece is separated from the wire, via a second state in which the workpiece is in contact with the wire, to a third state in which it moves in such a way as to bend the wire, and the estimating unit estimates the state of the wire based on the quantity supplied and the quantity discharged detected in the third state. Condition monitoring system for the wire saw according to claim 1, wherein the wire saw includes a first spool body that carries away the wire to be fed to the first processing roller, a second spool body that winds up the wire carried away from the second processing roller, a first driven roller arranged between the first processing roller and the first spool body and rotated with the movement of the wire, and a second driven roller arranged between the second processing roller and the second spool body and rotated with the movement of the wire, the first wire sensor detects the number of revolutions of the first driven roller as the quantity supplied, and the second wire sensor detects the number of revolutions of the second driven roller as the quantity dispensed. Condition monitoring system for the wire saw according to claim 6, wherein each of the first driven roller and the second driven roller is a guide roller that guides the wire. Condition monitoring system for the wire saw according to claim 6, wherein each of the first wire sensor and the second wire sensor includes a rotary encoder. Condition monitoring system for the wire saw according to claim 1, wherein each of the first wire sensor and the second wire sensor includes a detection device designed to detect a running speed of the wire. Wire saw comprising the condition monitoring system for the wire saw according to claim 1. Condition monitoring method for a wire saw, including a first processing roller and a second processing roller, a wire stretched over the first processing roller and the second processing roller, and a moving element that moves to press a workpiece against the wire between the first processing roller and the second processing roller while the wire is running, the condition monitoring method comprising: detecting a quantity of wire fed into the first processing roller by a first wire sensor; detecting a quantity of wire fed from the second processing roller by a second wire sensor; estimating a condition of the wire based on a difference between the quantity fed detected by the first wire sensor and the quantity discharged detected by the second wire sensor; and outputting an estimation result.

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