Grinding system and method for controlling grinding system

Abstract

To provide a better control method of a grinding system that grinds a work-piece in a gear wheel-shape by engaging the work-piece with a grinding tool having a spiral grinding tooth surface to rotate the work-piece.SOLUTION: A grinding system 10, which comprises a grinding device 11 that grinds a tooth surface 62 of a work-piece 12 in a gear wheel shape using a spiral grinding tooth surface 66 of a griding tool 14, by engaging the work-piece with the grinding tool to synchronously rotate the work-piece, is further provided with: an information obtaining part 92 that obtains information showing a synchronization error between the work-piece and the grinding tool during grinding of the work-piece tooth surface; and a determining part 96 that determines whether an abnormality occurs in grinding the tooth surface of the work-piece on the basis of the synchronization error.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] TECHNICAL FIELD The present disclosure relates to a grinding system and a method for controlling a grinding system. [Background technology]

[0002] Patent Document 1 discloses a grinding system equipped with a grinding device that grinds the workpiece tooth surface of a gear-shaped workpiece with a grinding tool by meshing the workpiece with the grinding tool and rotating the workpiece. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5467833 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a need for better grinding systems and methods of controlling grinding systems.

[0005] The present disclosure aims to solve the above-mentioned problems. [Means for solving the problem]

[0006] A first aspect of the present disclosure is a grinding system equipped with a grinding device that grinds the workpiece tooth surface of a gear-shaped workpiece with a grinding tool by meshing the workpiece with the grinding tool and rotating them synchronously, and the grinding system is equipped with an information acquisition unit that acquires information indicating a synchronization error between the workpiece and the grinding tool during grinding of the workpiece tooth surface, and a judgment unit that judges whether an abnormality has occurred in grinding the workpiece tooth surface based on the synchronization error.

[0007] A second aspect of the present disclosure is a control method for a grinding system equipped with a grinding device that grinds the workpiece tooth surface of a gear-shaped workpiece with a grinding tool by meshing the workpiece with the grinding tool and rotating them synchronously, the control method for a grinding system comprising: an information acquisition step of acquiring a signal indicating a synchronization error between the workpiece and the grinding tool during grinding of the workpiece tooth surface; and a judgment step of judging whether or not an abnormality has occurred in grinding of the workpiece tooth surface based on the synchronization error. [Effects of the Invention]

[0008] According to the present disclosure, a better grinding system and a method for controlling the grinding system may be provided. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing an example of a grinding system according to an embodiment. [Figure 2] FIG. 2 is a control block diagram of the grinding system. [Figure 3] FIG. 3 is a flowchart showing an example of a method for controlling the grinding system. [Figure 4] FIG. 4 is a graph for explaining the determination step. [Figure 5] FIG. 5 is a graph for explaining the determination step. DETAILED DESCRIPTION OF THE INVENTION

[0010] In recent years, efforts to realize a low-carbon or carbon-free society have become more active, and research and development of electric vehicles (e.g., hybrid vehicles, fuel cell vehicles) is being conducted to reduce CO2 emissions and improve energy efficiency. Such electric vehicles have quieter engine noise than conventional gasoline-fueled vehicles. Therefore, electric vehicles are required to reduce the noise generated by gear rotation more than gasoline-fueled vehicles. To reduce the noise generated by gear rotation, the workpiece tooth flank must be ground with high precision. If an abnormality occurs in the grinding of the workpiece tooth flank, the workpiece tooth flank cannot be ground with high precision. For example, an abnormality in the grinding of the workpiece tooth flank can occur due to vibration of a specific part of the grinding device during grinding. Whether the workpiece tooth flank has been ground with high precision can be confirmed by measuring the shape of each tooth flank of the product gear obtained after grinding. However, this requires a device to measure the shape of the tooth flank of the product gear and requires a significant amount of labor.

[0011] The present inventors have discovered that when the workpiece tooth surface is ground with a grinding tooth surface while rotating the workpiece and the grinding tool synchronously, there is a correlation between the synchronization error between the workpiece and the grinding tool and the grinding accuracy of the workpiece tooth surface. By focusing on this correlation, the present disclosure can provide a grinding system and a grinding system control method that can easily determine abnormalities in the grinding of the workpiece tooth surface.

[0012] Fig. 1 is a perspective view showing an example of a grinding system 10 according to an embodiment. As shown in Fig. 1, the grinding system 10 includes a grinding device 11 and a control device 26. The grinding device 11 grinds a gear-shaped workpiece 12 using a grinding tool 14. The grinding device 11 includes a bed 16, a gear support mechanism 18, a gear rotation mechanism 20, a tool support mechanism 22, and a tool rotation mechanism 24.

[0013] The bed 16 is placed on a horizontal surface, for example, in a factory. The gear support mechanism 18 is disposed on the flat upper surface of the bed 16. The gear support mechanism 18 has a cutting table 28, a cutting motor 30, a traverse table 32, and a traverse motor 34.

[0014] The cutting table 28 moves in the direction A relative to the bed 16. The direction A is a horizontal direction perpendicular to the height direction of the bed 16. The cutting table 28 is connected to a cutting motor 30 via a ball screw shaft 36. The cutting motor 30 moves the cutting table 28 in the direction A by rotating the ball screw shaft 36.

[0015] The traverse table 32 is disposed on the upper surface of the cutting table 28. The traverse table 32 moves in the direction B relative to the cutting table 28. The direction B is perpendicular to the height direction of the bed 16 and the direction A. The traverse table 32 is connected to a traverse motor 34 via a ball screw shaft (not shown). The traverse motor 34 moves the traverse table 32 in the direction B by rotating the ball screw shaft.

[0016] The gear rotation mechanism 20 is disposed on the upper surface of the traverse table 32. The gear rotation mechanism 20 has a gear mounting shaft 38 and a first motor 40. The gear mounting shaft 38 extends in the direction B. The workpiece 12 is detachably attached to the gear mounting shaft 38. The first motor 40 rotates the gear mounting shaft 38.

[0017] The tool support mechanism 22 has a column 42, a swivel table 44, a shift table 46, and a shift motor 48. The column 42 is disposed on the upper surface of the bed 16 so as to face the gear support mechanism 18. The column 42 extends upward from the bed 16. The swivel table 44 is attached to the surface of the column 42 facing the gear support mechanism 18.

[0018] The swivel table 44 extends in one direction. A swivel motor (not shown) swivels the swivel table 44 in direction C relative to the column 42. A shift table 46 is provided on the surface of the swivel table 44 facing the gear support mechanism 18. The shift table 46 is connected to a shift motor 48 via a ball screw shaft 50. The shift motor 48 is attached to the swivel table 44. The shift motor 48 moves the shift table 46 in direction D relative to the swivel table 44.

[0019] The tool rotation mechanism 24 has a base portion 54, a tool mounting shaft 56, and a second motor 58. The base portion 54 is attached to the surface of the shift table 46 that faces the gear support mechanism 18. The base portion 54 extends in the extension direction of the swivel table 44. The tool mounting shaft 56 is inserted through the base portion 54 in the extension direction of the base portion 54. The grinding tool 14 is detachably attached to the tool mounting shaft 56. The second motor 58 rotates the tool mounting shaft 56.

[0020] As shown in Figure 2, the workpiece 12 is attached to the gear mounting shaft 38. The workpiece 12 can be rotated in the R1 direction and the R2 direction by the driving force of the first motor 40. The workpiece 12 has a plurality of teeth 60. Each of the plurality of teeth 60 is formed with a workpiece tooth surface 62. The workpiece tooth surface 62 includes a left workpiece tooth surface 62a and a right workpiece tooth surface 62b.

[0021] The grinding tool 14 is attached to the tool mounting shaft 56. The grinding tool 14 can rotate in the R3 direction and the R4 direction by the driving force of the second motor 58. The grinding tool 14 is a tool for grinding the workpiece 12. The grinding tool 14 has a spiral grinding tooth 64. The grinding tooth 64 is formed with a grinding tooth surface 66. The grinding tooth surface 66 includes a first grinding tooth surface 66a and a second grinding tooth surface 66b. For example, a single layer of CBN (cubic boron nitride) abrasive grains or the like is electrodeposited on the grinding tooth surface 66 via a nickel plating layer.

[0022] When grinding the workpiece 12 with the grinding tool 14, the workpiece 12 and the grinding tool 14 are engaged. With the workpiece 12 and the grinding tool 14 engaged, the left workpiece tooth flank 62a faces the first grinding tooth flank 66a, and the right workpiece tooth flank 62b faces the second grinding tooth flank 66b. With the workpiece 12 and the grinding tool 14 engaged, for example, by rotating the workpiece 12 in the R1 direction and rotating the grinding tool 14 in the R3 direction, the left workpiece tooth flank 62a can be ground by the first grinding tooth flank 66a, and the right workpiece tooth flank 62b can be ground by the second grinding tooth flank 66b. In addition, with the workpiece 12 and the grinding tool 14 engaged, for example, by rotating the workpiece 12 in the R2 direction and rotating the grinding tool 14 in the R4 direction, the left workpiece tooth surface 62a can be ground by the first grinding tooth surface 66a and the right workpiece tooth surface 62b can be ground by the second grinding tooth surface 66b.

[0023] The grinding device 11 further includes a first encoder 68 and a second encoder 70. The first encoder 68 is provided in a state of being connected to the rotation shaft of the first motor 40. The first encoder 68 outputs information (e.g., a pulse signal) relating to the rotation phase (rotation speed, rotation angle, rotation position, and rotation amount) of the workpiece 12 to the control device 26.

[0024] The second encoder 70 is provided in a state of being coupled to the rotation shaft of the second motor 58. The second encoder 70 outputs information (e.g., a pulse signal) relating to the rotation phase (rotational speed, rotation angle, rotation position, and rotation amount) of the grinding tool 14 to the control device 26.

[0025] The control device 26 includes a first servo amplifier 74, a second servo amplifier 76, and a control main body 78. The first servo amplifier 74 controls the rotation of the first motor 40 based on a signal output from the control main body 78. The second servo amplifier 76 controls the rotation of the second motor 58 based on a signal output from the control main body 78.

[0026] The control main body 78 includes a calculation unit 80, a storage unit 82, an operation unit 84, and a display unit 86. The calculation unit 80 is configured by a processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). In other words, the calculation unit 80 is configured by processing circuitry.

[0027] The calculation unit 80 includes a control unit 88, a rotation control unit 90, an information acquisition unit 92, an analysis unit 94, a determination unit 96, a signal output unit 98, and a vibration location identification unit 100. The control unit 88 controls the infeed motor 30, the traverse motor 34, a swing motor (not shown), and the shift motor 48. The rotation control unit 90 controls the rotation of the workpiece 12 via the first servo amplifier 74. The rotation control unit 90 also controls the rotation of the grinding tool 14 via the second servo amplifier 76. The rotation control unit 90 controls the rotation of the workpiece 12 so that the rotation of the workpiece 12 is synchronized with the rotation of the grinding tool 14. The information acquisition unit 92 acquires information indicating a synchronization error between the workpiece 12 and the grinding tool 14. The analysis unit 94 analyzes the information acquired by the information acquisition unit 92. The determination unit 96 determines whether an abnormality has occurred in the grinding of the workpiece tooth surface 62 based on the synchronization error. The signal output unit 98 outputs an abnormality signal. The vibration part specifying unit 100 specifies the vibration part of the grinding device 11 based on the determination result of the determining unit 96 .

[0028] The control unit 88, the rotation control unit 90, the information acquisition unit 92, the analysis unit 94, the determination unit 96, the signal output unit 98, and the vibration part identification unit 100 can be realized by the calculation unit 80 executing a program stored in the storage unit 82. Note that at least a portion of the control unit 88, the rotation control unit 90, the information acquisition unit 92, the analysis unit 94, the determination unit 96, the signal output unit 98, and the vibration part identification unit 100 may be realized by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array). Furthermore, at least a portion of the control unit 88, the rotation control unit 90, the information acquisition unit 92, the analysis unit 94, the determination unit 96, the signal output unit 98, and the vibration part identification unit 100 may be configured by an electronic circuit including discrete devices.

[0029] The storage unit 82 is composed of a volatile memory (not shown) and a non-volatile memory (not shown). An example of the volatile memory is a random access memory (RAM). The volatile memory is used as a working memory for the processor, and temporarily stores data necessary for processing or calculation. An example of the non-volatile memory is a read-only memory (ROM) or a flash memory. The non-volatile memory is used as a storage memory, and stores programs, tables, maps, etc. At least a part of the storage unit 82 may be provided in the processor, integrated circuit, etc. described above.

[0030] The operation unit 84 is used when the user operates the control device 26. The operation unit 84 may include a keyboard, a mouse, etc. The display unit 86 is provided with a display element (not shown). For example, a liquid crystal display element, an organic electroluminescence display element, etc. may be used as the display element. The operation unit 84 and the display unit 86 may be configured by a touch panel (not shown) provided with such a display element.

[0031] Next, a description will be given of an example of a control method for the grinding system 10. Fig. 3 is a flowchart showing an example of the control method for the grinding system 10. Note that, in an initial state, the grinding tool 14 is attached to the tool attachment shaft 56.

[0032] In step S1, the workpiece 12 is mounted on the gear mounting shaft 38. After this, the process proceeds to step S2.

[0033] In step S2, the workpiece 12 is meshed with the grinding tool 14. Specifically, the control unit 88 controls the cutting motor 30, the traverse motor 34, a turning motor (not shown), and the shift motor 48 to mesh the workpiece 12 with the grinding tool 14. After this, the process proceeds to step S3.

[0034] In step S3, a grinding step is performed. In the grinding step, the workpiece tooth surface 62 is ground by the grinding tooth surface 66. The rotation control unit 90 rotates the workpiece 12 via the first servo amplifier 74 and rotates the grinding tool 14 via the second servo amplifier 76. The rotation control unit 90 rotates the workpiece 12 and the grinding tool 14 synchronously. In other words, the rotation control unit 90 feedback-controls the first servo amplifier 74 and the second servo amplifier 76 based on information output from the first encoder 68 and information output from the second encoder 70 so that the workpiece 12 and the grinding tool 14 rotate while maintaining their meshed state. Note that the rotation control unit 90 may also perform control by incorporating information output from an encoder provided in the traverse motor 34 (the traverse speed in the tooth width direction of the workpiece 12) as a synchronization signal. In the grinding step, grinding is performed around one circumference of the workpiece 12 (all of the workpiece tooth surfaces 62). In the grinding step, grinding may be performed multiple times (for example, first rough grinding, second rough grinding, and finish grinding) on ​​the workpiece tooth surface 62. After this, the process proceeds to step S4.

[0035] In step S4, an information acquisition step is performed. In the information acquisition step, the information acquisition unit 92 acquires a signal indicating a synchronization error between the workpiece 12 and the grinding tool 14 during grinding of the workpiece tooth surface 62. The information acquisition step may be performed in parallel with the grinding step. Specifically, the information acquisition step acquires phase difference data between the rotational phase of the workpiece 12 detected by the first encoder 68 and the rotational phase of the grinding tool 14 detected by the second encoder 70 as information indicating the synchronization error. The phase difference data is, for example, a stagnant pulse. After this, the process proceeds to step S5.

[0036] In step S5, an analysis step is performed. In the analysis step, the analysis unit 94 obtains analysis data by frequency analysis of the phase difference data. Specifically, the analysis unit 94 obtains analysis data by performing a fast Fourier transform on the phase difference data. After this, the process proceeds to step S6.

[0037] In step S6, the determination unit 96 performs a determination step of determining, based on the synchronization error, whether or not an abnormality has occurred in grinding of the workpiece tooth surface 62. That is, in the determination step, it is determined that an abnormality has occurred in grinding of the workpiece tooth surface 62 when the peak value of the phase difference data included in a predetermined frequency band of the analysis data is equal to or greater than a predetermined threshold value for that frequency band.

[0038] In this embodiment, a plurality of frequency bands may be determined in advance according to the natural frequencies of a plurality of portions of the grinding machine 11 where vibrations are expected to occur. Specifically, a first frequency band and a second frequency band are determined in advance. The first frequency band corresponds to the natural frequency of the gear mounting shaft 38, for example. The second frequency band corresponds to the natural frequency of the tool mounting shaft 56, for example.

[0039] 4 and 5 are graphs illustrating the determination step. In FIG. 4, the horizontal axis represents the peak value of the phase difference data included in the first frequency band, and the vertical axis represents the amount of waviness of the tooth surface of the product gear obtained after grinding the workpiece tooth surface 62. As indicated by the dashed line L1 in FIG. 4, the amount of waviness is proportional to the peak value of the phase difference data included in the first frequency band. Note that the dashed line L1 is obtained by conducting a test in advance. In this case, the amount of waviness reaches the upper limit value W when the peak value of the phase difference data in the first frequency band is Ta. Note that the upper limit value W is appropriately set depending on the shape and size of the product gear. In this embodiment, the first threshold value T1 of the peak value of the phase difference data in the first frequency band is obtained by adding a safety factor to Ta. Note that the first threshold value T1 may be the same as Ta. In the determination step, the determination unit 96 determines that an abnormality has occurred in the grinding of the workpiece tooth surface 62 if the peak value of the phase difference data included in the first frequency band is equal to or greater than the first threshold value T1.

[0040] In FIG. 5, the horizontal axis represents the peak value of the phase difference data included in the second frequency band, and the vertical axis represents the amount of waviness of the tooth surface of the product gear obtained after grinding the workpiece tooth surface 62. As indicated by the dashed line L2 in FIG. 5, the amount of waviness is proportional to the peak value of the phase difference data included in the second frequency band. Note that the dashed line L2 is obtained by conducting a test in advance. In this case, the amount of waviness reaches the upper limit value W when the peak value of the phase difference data in the second frequency band is Tb. In this embodiment, the second threshold value T2 of the peak value of the phase difference data in the second frequency band is obtained by adding a safety factor to Tb. Note that the second threshold value T2 may be the same as Tb. In the determination step, the determination unit 96 determines that an abnormality has occurred in the grinding of the workpiece tooth surface 62 if the peak value of the phase difference data included in the second frequency band is equal to or greater than the second threshold value T2.

[0041] Specifically, for example, assume that the analysis result in the analysis step indicates that the peak value of the phase difference data included in the first frequency band is Pa1 and the peak value of the phase difference data included in the second frequency band is Pa2. Pa1 is smaller than the first threshold value T1 (see FIG. 4), and Pa2 is smaller than the second threshold value T2 (see FIG. 5). In this case, the determination unit 96 determines that no abnormality has occurred in the grinding of the workpiece tooth surface 62.

[0042] Furthermore, suppose that the analysis result in the analysis step indicates that the peak value of the phase difference data included in the first frequency band is Pb1 and the peak value of the phase difference data included in the second frequency band is Pb2. Pb1 is greater than the first threshold value T1 (see FIG. 4), and Pb2 is smaller than the second threshold value T2 (see FIG. 5). In this case, the determination unit 96 determines that an abnormality has occurred in the grinding of the workpiece tooth surface 62.

[0043] Furthermore, suppose that the analysis result in the analysis step indicates that the peak value of the phase difference data included in the first frequency band is Pc1 and the peak value of the phase difference data included in the second frequency band is Pc2. Pc1 is smaller than the first threshold value T1 (see FIG. 4), and Pc2 is larger than the second threshold value T2 (see FIG. 5). In this case, the determination unit 96 determines that an abnormality has occurred in the grinding of the workpiece tooth surface 62.

[0044] Furthermore, suppose that the analysis result in the analysis step indicates that the peak value of the phase difference data included in the first frequency band is Pd1 and the peak value of the phase difference data included in the second frequency band is Pd2. Pd1 is greater than the first threshold value T1 (see FIG. 4), and Pd2 is greater than the second threshold value T2 (see FIG. 5). In this case, the determination unit 96 determines that an abnormality has occurred in the grinding of the workpiece tooth surface 62.

[0045] That is, in the determination step, if the peak value of the phase difference data is equal to or greater than a threshold value in at least one frequency band, it is determined that an abnormality has occurred in the grinding of the workpiece tooth surface 62. The above-described analysis step and determination step are performed every time the grinding step is completed. In addition, the analysis step and determination step may be performed, for example, while the product gear is removed from the gear mounting shaft 38 and transported to the next process.

[0046] If it is determined in the determination step that an abnormality has occurred in the grinding of the workpiece tooth surface 62 (YES in step S6), the process proceeds to step S7. In step S7, a signal output step is performed. In the signal output step, the signal output unit 98 outputs an abnormality signal indicating an abnormality in the grinding of the workpiece tooth surface 62. This makes it possible, for example, to remove a product gear in which a grinding abnormality has occurred from the production line based on the abnormality signal. After this, the process proceeds to step S8.

[0047] In step S8, a vibration part identification step is performed. In the vibration part identification step, the vibration part identification unit 100 identifies a vibration part of the grinding machine 11 based on the determination result of the determination step. Specifically, for example, if the determination step determines that the peak value of the phase difference data included in the first frequency band is equal to or greater than the first threshold value T1, the vibration part identification unit 100 identifies the part (gear mounting shaft 38) having a natural frequency corresponding to the first frequency band as the vibration part. Also, for example, if the determination step determines that the peak value of the phase difference data included in the second frequency band is equal to or greater than the second threshold value T2, the vibration part identification unit 100 identifies the part (tool mounting shaft 56) having a natural frequency corresponding to the second frequency band as the vibration part. The control unit 88, for example, causes the display unit 86 to display information about the vibration part identified by the vibration part identification unit 100. This allows the user to identify the vibration part and perform appropriate processing, such as investigating the cause of the vibration. After this, the process proceeds to step S9.

[0048] In step S9, the control unit 88 stops driving the grinding system 10. After this, the processing of FIG.

[0049] If it is determined in the determination step that no abnormality has occurred in the grinding of the workpiece tooth surface 62 (NO in step S6), the process proceeds to step S10. In step S10, the determination unit 96 determines whether grinding of all workpieces 12 has been completed. In other words, the determination unit 96 determines whether grinding of a predetermined number of workpieces 12 (e.g., N workpieces 12) has been completed. If the determination unit 96 determines that grinding of all workpieces 12 has not been completed (NO in step S10), the process proceeds to step S1. If the determination unit 96 determines that grinding of all workpieces 12 has been completed (YES in step S10), the process of step S9 is performed, and then the process of FIG. 3 is completed.

[0050] According to this embodiment, whether or not an abnormality has occurred in the grinding of the workpiece tooth surface 62 is determined based on the synchronization error between the workpiece 12 and the grinding tool 14. This makes it possible to easily determine whether or not an abnormality has occurred in the grinding of the workpiece tooth surface 62. Therefore, it is possible to provide a better grinding system 10 and a control method for the grinding system 10.

[0051] The following additional notes are further disclosed regarding the above embodiment.

[0052] (Appendix 1) The grinding system (10) of the present disclosure is a grinding system including a grinding device (11) that grinds a workpiece tooth surface (62) of a gear-shaped workpiece (12) with a grinding tool (14) by meshing the workpiece with the grinding tool and rotating them synchronously, and includes an information acquisition unit (92) that acquires information indicating a synchronization error between the workpiece and the grinding tool during grinding of the workpiece tooth surface, and a determination unit (96) that determines whether an abnormality has occurred in grinding the workpiece tooth surface based on the synchronization error.

[0053] With this configuration, whether or not an abnormality has occurred in grinding of the workpiece tooth surface is determined based on the synchronization error between the workpiece and the grinding tool. This makes it possible to easily determine whether or not an abnormality has occurred in grinding of the workpiece tooth surface. Therefore, it is possible to provide a better grinding system and a method for controlling the grinding system.

[0054] (Appendix 2) In the grinding system described in Appendix 1, the information acquisition unit may acquire, as the information indicating the synchronization error, phase difference data between the rotational phase of the workpiece detected by a first encoder (68) and the rotational phase of the grinding tool detected by a second encoder (70).

[0055] With this configuration, information about the synchronization error can be easily obtained.

[0056] (Appendix 3) The grinding system described in Appendix 2 may further include an analysis unit (94) that obtains analysis data by performing frequency analysis on the phase difference data, and the determination unit may determine that the abnormality has occurred when a peak value of the phase difference data included in a predetermined frequency band of the analysis data obtained by the analysis unit is equal to or greater than predetermined threshold values ​​(T1, T2) for the frequency band.

[0057] According to this configuration, by using the peak value of the phase difference data included in a specific frequency band, it is possible to accurately determine whether or not an abnormality has occurred in the grinding of the workpiece tooth surface.

[0058] (Appendix 4) The grinding system described in Appendix 3 may further include a vibration part identification unit (100) that, when the determination unit determines that the abnormality has occurred, identifies the vibration part of the grinding device based on the determination result, wherein the frequency band is determined based on the natural frequency of a part of the grinding device where vibration is expected to occur.

[0059] With this configuration, if a specific part of the grinding machine vibrates and an abnormality occurs in grinding the tooth surface of the workpiece, the vibrating part can be easily identified, allowing the user to understand the vibrating part and take appropriate action.

[0060] (Appendix 5) The grinding system described in any one of Supplementary Notes 1 to 4 may further include a signal output unit (98) that outputs an abnormality signal indicating the abnormality when the determination unit determines that the abnormality has occurred.

[0061] With this configuration, it is possible to take appropriate action, such as removing a product gear in which a grinding abnormality has occurred, from the production line based on the abnormality signal output from the signal output unit.

[0062] (Appendix 6) The control method for a grinding system disclosed herein is a control method for a grinding system equipped with a grinding device that grinds the workpiece tooth surface of a gear-shaped workpiece with a grinding tool by meshing the workpiece with the grinding tool and rotating them synchronously, and includes an information acquisition step of acquiring a signal indicating a synchronization error between the workpiece and the grinding tool during grinding of the workpiece tooth surface, and a judgment step of judging whether or not an abnormality has occurred in grinding of the workpiece tooth surface based on the synchronization error.

[0063] This method provides the same effect as that of Supplementary Note 1. Therefore, it is possible to provide a better method for controlling a grinding system.

[0064] (Appendix 7) In the grinding system control method described in Appendix 6, the information acquisition step may acquire phase difference data between the rotational phase of the workpiece detected by a first encoder and the rotational phase of the grinding tool detected by a second encoder as information indicating the synchronization error.

[0065] According to this method, the same effect as that of Supplementary Note 2 can be achieved.

[0066] (Appendix 8) In the grinding system control method described in Appendix 7, the determination step may determine that the abnormality has occurred when a peak value of the phase difference data included in a predetermined frequency band of analysis data obtained by frequency analysis of the phase difference data is equal to or greater than a predetermined threshold value of the frequency band.

[0067] According to this method, the same effect as that of Supplementary Note 3 can be achieved.

[0068] (Appendix 9) The grinding system control method described in Appendix 8 may further include a vibration part identification step of identifying the vibrating part of the grinding device based on the frequency band that includes the peak value that exceeds the threshold value when the frequency band is determined based on the natural frequency of a part of the grinding device where vibration is expected to occur, and when the determination step determines that the abnormality has occurred, the control method may further include a vibration part identification step of identifying the vibrating part of the grinding device based on the frequency band that includes the peak value that exceeds the threshold value.

[0069] According to this method, the same effect as that of Supplementary Note 4 can be achieved.

[0070] (Appendix 10) The control method for a grinding system described in any one of Appendices 6 to 9 may further include a signal output step of outputting an abnormality signal indicating the abnormality when the determination step determines that the abnormality has occurred.

[0071] According to this method, the same effect as that of Supplementary Note 5 can be achieved.

[0072] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. These embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values ​​or mathematical expressions are used in the description of the above-described embodiments. [Explanation of symbols]

[0073] 10... Grinding system 11... Grinding device 12...Workpiece 14...Grinding tool 62...Workpiece tooth surface 64...Ground tooth 66... ​​Ground tooth surface 68... First encoder 70... Second encoder 92... Information acquisition unit 94...Analysis section 96...Judgment section 98...signal output unit 100...vibration part identification unit T1...First threshold (threshold) T2...Second threshold (threshold)

Claims

1. A grinding system including a grinding device that grinds a work tooth surface of a gear-shaped workpiece with a grinding tool by meshing the workpiece with the grinding tool and rotating the workpiece synchronously, the grinding system comprising: an information acquiring unit that acquires information indicating a synchronization error between the workpiece and the grinding tool during grinding of the workpiece tooth surface; a determination unit that determines whether or not an abnormality has occurred in grinding the tooth surface of the workpiece based on the synchronization error; Equipped with the information acquisition unit acquires, as the information indicating the synchronization error, phase difference data between a rotational phase of the workpiece detected by a first encoder and a rotational phase of the grinding tool detected by a second encoder; an analysis unit that obtains analysis data by frequency analyzing the phase difference data, The determination unit determines that the abnormality has occurred when a peak value of the phase difference data included in a predetermined frequency band of the analysis data obtained by the analysis unit is equal to or greater than a predetermined threshold value of the frequency band.

2. 10. The grinding system of claim 1, the frequency band is determined based on the natural frequency of a portion of the grinding machine where vibration is expected to occur, The grinding system further includes a vibration part identifying unit that identifies a vibration part of the grinding device based on a determination result when the determining unit determines that the abnormality has occurred.

3. 3. The grinding system according to claim 1 or 2, The grinding system further includes a signal output unit that outputs an abnormality signal indicating the abnormality when the determination unit determines that the abnormality has occurred.

4. A control method for a grinding system including a grinding device that grinds a work tooth surface of a gear-shaped workpiece with a grinding tool by meshing the workpiece with the grinding tool and rotating the workpiece synchronously, the method comprising: an information acquiring step of acquiring a signal indicating a synchronization error between the workpiece and the grinding tool during grinding of the workpiece tooth surface; a determining step of determining whether or not an abnormality has occurred in grinding of the workpiece tooth surface based on the synchronization error; Equipped with the information acquiring step acquires, as information indicating the synchronization error, phase difference data between a rotational phase of the workpiece detected by a first encoder and a rotational phase of the grinding tool detected by a second encoder; In the determination step, it is determined that the abnormality has occurred when a peak value of the phase difference data included in a predetermined frequency band of analysis data obtained by frequency analysis of the phase difference data is equal to or greater than a predetermined threshold value of the frequency band.

5. 5. A method for controlling a grinding system according to claim 4, comprising: the frequency band is determined based on the natural frequency of a portion of the grinding machine where vibration is expected to occur, The grinding system control method further includes a vibration part identifying step of identifying a vibration part of the grinding device based on the frequency band including the peak value exceeding the threshold value when it is determined in the determination step that the abnormality has occurred.

6. 6. A method for controlling a grinding system according to claim 4 or 5, comprising: The grinding system control method further comprises a signal output step of outputting an abnormality signal indicating the abnormality when it is determined in the determination step that the abnormality has occurred.

Images