Grinding system and control method of grinding system

Abstract

The invention provides a grinding system and a control method of the grinding system. A grinding system (10) is provided with a grinding device (11) for grinding a workpiece tooth surface (62) of a gear-shaped workpiece (12) and a grinding tool (14) with a spiral grinding tooth surface (66) of the grinding tool by causing the gear-shaped workpiece (12) and the grinding tool (14) to mesh and rotate synchronously, and is provided with an information acquisition unit (92) and a determination unit (96), the information acquisition part acquires information representing the synchronization error of the workpiece and the grinding tool in the grinding process of the tooth surface of the workpiece; the determination unit determines whether or not there is an abnormality in the grinding of the tooth surface of the workpiece on the basis of the synchronization error. Therefore, a better grinding system and a control method of the grinding system can be provided.

Description

Technical Field

[0001] The present invention relates to a grinding system and a method for controlling a grinding system. Background Art

[0002] Japanese Patent Application No. 5467833 discloses a grinding system having a grinding device for grinding a gear-shaped workpiece (workpiece) with a grinding tool by meshing and rotating the workpiece and using the helical grinding tooth surface of the grinding tool to grind the workpiece tooth surface. Summary of the Invention

[0003] We look forward to better grinding systems and grinding system control methods.

[0004] The purpose of the present invention is to solve the above technical problems.

[0005] A first embodiment of the present invention is a grinding system comprising a grinding device for grinding a workpiece tooth surface of the workpiece with a spiral grinding tooth surface of the grinding tool by meshing and synchronously rotating a gear-shaped workpiece and a grinding tool. The grinding system comprises an information acquisition unit and a determination unit, wherein the information acquisition unit acquires information indicating a synchronization error between the workpiece and the grinding tool during the grinding of the workpiece tooth surface; and the determination unit determines whether an abnormality occurs in the grinding of the workpiece tooth surface based on the synchronization error.

[0006] A second embodiment of the present invention is a method for controlling a grinding system, wherein the grinding system includes a grinding device for grinding a workpiece tooth surface of the workpiece with a spiral grinding tooth surface of the grinding tool by meshing and synchronously rotating a gear-shaped workpiece and a grinding tool. The method for controlling the grinding system includes an information acquisition step and a judgment step, wherein, in the information acquisition step, information indicating a synchronization error between the workpiece and the grinding tool during the grinding of the workpiece tooth surface is acquired; and in the judgment step, whether an abnormality occurs in the grinding of the workpiece tooth surface is determined based on the synchronization error.

[0007] According to the present invention, a more excellent grinding system and a method for controlling the grinding system can be provided.

[0008] The above-mentioned objects, features and advantages will be easily understood from the following description of the embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a perspective view showing an example of a grinding system according to the embodiment.

[0010] Figure 2 It is the control block diagram of the grinding system.

[0011] Figure 3 This is a flowchart showing an example of a control method of a grinding system.

[0012] Figure 4 It is a graph for explaining the determination steps.

[0013] Figure 5 It is a graph for explaining the determination steps. DETAILED DESCRIPTION

[0014] In recent years, efforts to realize a low-carbon society or a decarbonized society have been actively made. In order to reduce CO2 emissions and improve energy efficiency, research and development of electric vehicles (hybrid vehicles, fuel cell vehicles, etc.) are being carried out. Compared with existing general gasoline-fueled vehicles, the engine noise of such electric vehicles is small. Therefore, compared with gasoline-fueled vehicles, it is required to reduce the noise generated when the gears rotate in electric vehicles. In order to reduce the noise generated when the gears rotate, it is necessary to grind the workpiece tooth surface with high precision. If an abnormality occurs in the grinding of the workpiece tooth surface, the workpiece tooth surface cannot be ground with high precision. The grinding abnormality of the workpiece tooth surface may be caused, for example, by vibration of a specific part of the grinding device during the grinding process of the workpiece tooth surface. By measuring the shape of the tooth surface of the product gear obtained after grinding the workpiece tooth surface one by one, it can be confirmed whether the workpiece tooth surface is ground with high precision. However, in this case, a device for measuring the shape of the tooth surface of the product gear is required, and a lot of man-hours are required.

[0015] The inventors of this application have discovered that when a workpiece tooth surface is ground using a grinding tool while the workpiece and grinding tool rotate synchronously, the synchronization error between the workpiece and grinding tool is correlated with the grinding accuracy of the workpiece tooth surface. The present invention addresses this correlation and provides a grinding system and a method for controlling the grinding system that can easily detect abnormalities in the grinding of workpiece tooth surfaces.

[0016] Figure 1 1 is a perspective view showing an example of a grinding system 10 according to an embodiment. Figure 1 As shown, 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 rotating mechanism 20, a tool support mechanism 22, and a tool rotating mechanism 24.

[0017] The bed 16 is placed on a horizontal surface in a factory, for example. The gear support mechanism 18 is arranged on the flat upper surface of the bed 16. The gear support mechanism 18 includes a feed table (cutting table) 28, a feed motor (cutting motor) 30, a traverse table 32, and a traverse motor 34.

[0018] The feed 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 feed table 28 is connected to the feed motor 30 via a ball screw shaft 36. The feed motor 30 rotates the ball screw shaft 36 to move the feed table 28 in the direction A.

[0019] The traverse table 32 is disposed on the upper surface of the feed table 28. The traverse table 32 moves relative to the feed table 28 in the direction B. The direction B is perpendicular to the height direction of the bed 16 and the direction A. The traverse table 32 is connected to the traverse motor 34 via a ball screw shaft (not shown). The traverse motor 34 rotates the ball screw shaft to move the traverse table 32 in the direction B.

[0020] The gear rotating mechanism 20 is disposed on the upper surface of the traverse table 32. The gear rotating mechanism 20 includes a gear mounting shaft 38 and a first motor 40. The gear mounting shaft 38 extends in the direction B. The workpiece 12 is attachable to and detachable from the gear mounting shaft 38. The first motor 40 rotates the gear mounting shaft 38.

[0021] The tool support mechanism 22 includes a column 42, a rotary 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 rotary table 44 is mounted on the surface of the column 42 facing the gear support mechanism 18.

[0022] The turntable 44 extends in one direction. A rotary motor (not shown) rotates the turntable 44 in the C direction relative to the column 42. A displacement table 46 is provided on the surface of the turntable 44 facing the gear support mechanism 18. The displacement table 46 is connected to a displacement motor 48 via a ball screw shaft 50. The displacement motor 48 is mounted on the turntable 44. The displacement motor 48 moves the displacement table 46 in the D direction relative to the turntable 44.

[0023] The tool rotation mechanism 24 includes a base 54, a tool mounting shaft 56, and a second motor 58. The base 54 is mounted on the surface of the displacement table 46 facing the gear support mechanism 18. The base 54 extends along the direction in which the turntable 44 extends. The tool mounting shaft 56 penetrates the base 54 along the direction in which the base 54 extends. The grinding tool 14 is attachable to and detachable from the tool mounting shaft 56. The second motor 58 rotates the tool mounting shaft 56.

[0024] like Figure 2 As shown, the workpiece 12 is mounted on the gear mounting shaft 38. The workpiece 12 can rotate 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 teeth 60 has a workpiece tooth surface 62. The workpiece tooth surface 62 includes a left workpiece tooth surface 62a and a right workpiece tooth surface 62b.

[0025] The grinding tool 14 is mounted on 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 spiral grinding teeth 64. Grinding tooth surfaces 66 are formed on the grinding teeth 64. The grinding tooth surfaces 66 include a first grinding tooth surface 66a and a second grinding tooth surface 66b. A single layer of CBN (cubic boron nitride) abrasive grains, for example, is electrodeposited on the grinding tooth surfaces 66 via a nickel plating layer.

[0026] When the workpiece 12 is ground using the grinding tool 14, the workpiece 12 is meshed with the grinding tool 14. When the workpiece 12 and the grinding tool 14 are meshed, the left workpiece tooth surface 62a faces the first grinding tooth surface 66a, and the right workpiece tooth surface 62b faces the second grinding tooth surface 66b. When the workpiece 12 and the grinding tool 14 are meshed, for example, by rotating the workpiece 12 in the R1 direction and the grinding tool 14 in the R3 direction, the left workpiece tooth surface 62a is ground by the first grinding tooth surface 66a, and the right workpiece tooth surface 62b is ground by the second grinding tooth surface 66b. In addition, when the workpiece 12 is engaged with the grinding tool 14, for example, the workpiece 12 is rotated in the R2 direction and the grinding tool 14 is rotated in the R4 direction, thereby also being able to use the first grinding tooth surface 66a to grind the left workpiece tooth surface 62a and the second grinding tooth surface 66b to grind the right workpiece tooth surface 62b.

[0027] The grinding device 11 further includes a first encoder 68 and a second encoder 70. The first encoder 68 is provided in a state connected to the rotating shaft of the first motor 40. The first encoder 68 outputs information (e.g., a pulse signal) related to the rotation phase (rotation speed, rotation angle, rotation position, rotation amount) of the workpiece 12 to the control device 26.

[0028] The second encoder 70 is connected to the rotation shaft of the second motor 58 and outputs information (eg, pulse signal) on the rotation phase (rotation speed, rotation angle, rotation position, rotation amount) of the grinding tool 14 to the control device 26 .

[0029] The control device 26 includes a first servo amplifier 74, a second servo amplifier 76, and a control main unit 78. The first servo amplifier 74 controls the rotation of the first motor 40 based on a signal output from the control main unit 78. The second servo amplifier 76 controls the rotation of the second motor 58 based on a signal output from the control main unit 78.

[0030] The control main unit 78 includes a computing unit 80, a storage unit 82, an operating unit 84, and a display unit 86. The computing unit 80 is composed of a processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). In other words, the computing unit 80 is composed of processing circuitry.

[0031] The computing 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 feed motor 30, the traverse motor 34, the rotary motor (not shown), and the displacement motor 48. The rotation control unit 90 controls the rotation of the workpiece 12 via the first servo amplifier 74. Furthermore, the rotation control unit 90 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 site identification unit 100 identifies the vibration site of the grinding device 11 based on the determination result of the determination unit 96 .

[0032] 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 site identification unit 100 can be implemented by the calculation unit 80 executing a program stored in the storage unit 82. 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 site identification unit 100 can be implemented using 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 site identification unit 100 can also be formed using an electronic circuit including discrete devices.

[0033] The storage unit 82 is composed of a volatile memory (not shown) and a non-volatile memory (not shown). Examples of volatile memory include RAM (Random Access Memory). Volatile memory is used as working memory for the processor, temporarily storing data required for processing or calculations. Examples of non-volatile memory include ROM (Read Only Memory) and flash memory. Non-volatile memory is used as storage memory, storing programs, tables, maps, etc. At least a portion of the storage unit 82 may be provided on the processor, integrated circuit, etc. described above.

[0034] The operating unit 84 is used by the user to operate the control device 26. Furthermore, the operating unit 84 may include a keyboard, a mouse, or the like. A display element (not shown) is provided on the display unit 86. Examples of such display elements include liquid crystal display elements and organic electroluminescent display elements. Alternatively, the operating unit 84 and the display unit 86 may be configured using a touch panel (not shown) having such a display element.

[0035] Next, an example of a control method of the grinding system 10 will be described. Figure 3 1 is a flowchart showing an example of a control method of the grinding system 10. In the initial state, the grinding tool 14 is mounted on the tool mounting shaft 56.

[0036] In step S1, the workpiece 12 is mounted on the gear mounting shaft 38. Thereafter, the process proceeds to step S2.

[0037] In step S2, the workpiece 12 is meshed with the grinding tool 14. Specifically, the control unit 88 controls the feed motor 30, the traverse motor 34, the rotation motor (not shown), and the displacement motor 48 to mesh the workpiece 12 with the grinding tool 14. Thereafter, the process moves to step S3.

[0038] In step S3, a grinding step is performed. In the grinding step, the workpiece tooth surface 62 is ground using the grinding tooth surface 66. The rotation control unit 90 rotates the workpiece 12 through the first servo amplifier 74 and rotates the grinding tool 14 through the second servo amplifier 76. The rotation control unit 90 causes the workpiece 12 and the grinding tool 14 to rotate synchronously. In other words, the rotation control unit 90 performs feedback control on the first servo amplifier 74 and the second servo amplifier 76 based on the information output from the first encoder 68 and the information output from the second encoder 70 so that the workpiece 12 and the grinding tool 14 rotate while maintaining engagement. In addition, the rotation control unit 90 can input and control the information output from the 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 within the entire circumference of the workpiece 12 (all workpiece tooth surfaces 62). In the grinding step, multiple grinding steps (for example, first rough grinding, second rough grinding, and finish grinding) can be performed on the workpiece tooth surface 62. Thereafter, the process proceeds to step S4.

[0039] In step S4, an information acquisition step is performed. In this step, the information acquisition unit 92 acquires a signal indicating the synchronization error between the workpiece 12 and the grinding tool 14 during the grinding process of the workpiece tooth surface 62. The information acquisition step can be performed in parallel with the grinding process. 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 may be, for example, accumulated pulses. The process then moves to step S5.

[0040] In step S5, an analysis step is performed. In the analysis step, the analysis unit 94 obtains analysis data by performing frequency analysis on the phase difference data. Specifically, the analysis unit 94 obtains analysis data by performing a fast Fourier transform on the phase difference data. Thereafter, the process moves to step S6.

[0041] In step S6, the determination unit 96 performs a determination step for determining whether an abnormality has occurred in the grinding of the workpiece tooth surface 62 based on the synchronization error. Specifically, in the determination step, if the peak value of the phase difference data included in the analysis data within a predetermined frequency band is greater than or equal to a predetermined threshold value for that frequency band, it is determined that an abnormality has occurred in the grinding of the workpiece tooth surface 62.

[0042] In this embodiment, multiple frequency bands can be predetermined based on the natural vibration frequencies of multiple locations in the grinding device 11 where vibration is expected to occur. Specifically, a first frequency band and a second frequency band are predetermined. The first frequency band corresponds to the natural vibration frequency of the gear mounting shaft 38, for example. The second frequency band corresponds to the natural vibration frequency of the tool mounting shaft 56, for example.

[0043] Figure 4 and Figure 5 It is a graph used to illustrate the determination steps. Figure 4 In FIG. 1 , the horizontal axis is the peak value of the phase difference data included in the first frequency band, and the vertical axis is the fluctuation amount of the tooth surface of the product gear obtained after grinding the workpiece tooth surface 62. Figure 4 As shown by the dotted line L1, the fluctuation amount is proportional to the peak value of the phase difference data contained in the first frequency band. In addition, the dotted line L1 is obtained by conducting experiments in advance. In this case, when the peak value of the phase difference data in the first frequency band is Ta, the fluctuation amount reaches the upper limit value W. In addition, the upper limit value W is appropriately set according to the shape and size of the product gear. In the present embodiment, the first threshold value T1 of the peak value of the phase difference data in the first frequency band is obtained by taking the safety factor into account in Ta. In addition, the first threshold value T1 may also be the same as Ta. In the judgment step, when the peak value of the phase difference data contained in the first frequency band is greater than the first threshold value T1, the judgment unit 96 determines that an abnormality has occurred in the grinding of the workpiece tooth surface 62.

[0044] exist Figure 5 In FIG. 1 , the horizontal axis is the peak value of the phase difference data included in the second frequency band, and the vertical axis is the fluctuation amount of the tooth surface of the product gear obtained after grinding the workpiece tooth surface 62. Figure 5 As shown by the dotted line L2, the fluctuation amount is proportional to the peak value of the phase difference data contained in the second frequency band. In addition, the dotted line L2 is obtained by conducting experiments in advance. In this case, when the peak value of the phase difference data in the second frequency band is Tb, the fluctuation amount reaches the upper limit value W. 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 taking into account the safety factor in Tb. In addition, the second threshold value T2 may also be the same as Tb. In the judgment step, when the peak value of the phase difference data contained in the second frequency band is greater than the second threshold value T2, the judgment unit 96 determines that an abnormality has occurred in the grinding of the workpiece tooth surface 62.

[0045] Specifically, for example, it is assumed that the result of the analysis in the analysis step is 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 (refer to Figure 4 ), Pa2 is less than the second threshold T2 (refer to Figure 5 In this case, the determination unit 96 determines that no abnormality has occurred in the grinding of the workpiece tooth surface 62 .

[0046] Furthermore, it is assumed that the result of the analysis in the analysis step is 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 larger than the first threshold value T1 (refer to Figure 4 ), Pb2 is less than the second threshold value T2 (refer to Figure 5 In this case, the determination unit 96 determines that an abnormality has occurred in the grinding of the workpiece tooth surface 62 .

[0047] Furthermore, it is assumed that the result of the analysis in the analysis step is 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 (refer to Figure 4 ), Pc2 is greater than the second threshold T2 (refer to Figure 5 In this case, the determination unit 96 determines that an abnormality has occurred in the grinding of the workpiece tooth surface 62 .

[0048] Furthermore, it is assumed that the result of the analysis in the analysis step is 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 larger than the first threshold value T1 (refer to Figure 4 ), Pd2 is greater than the second threshold T2 (refer to Figure 5 In this case, the determination unit 96 determines that an abnormality has occurred in the grinding of the workpiece tooth surface 62 .

[0049] Specifically, in the determination step, if the peak value of the phase difference data in at least one frequency band is greater than or equal to a threshold, it is determined that an abnormality has occurred in the grinding of the workpiece tooth surface 62. The above-described analysis and determination steps are performed each time the grinding step is completed. Furthermore, the analysis and determination steps can be performed, for example, while the product gear is being removed from the gear mounting shaft 38 and transported to the next process.

[0050] If the determination step determines 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 this 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 allows, for example, the production gear experiencing a grinding abnormality to be removed from the production line based on the abnormality signal. The process then proceeds to step S8.

[0051] In step S8, a vibration part identification step is performed. In the vibration part identification step, the vibration part identification unit 100 identifies the vibration part of the grinding device 11 based on the determination result of the determination step. Specifically, in the determination step, for example, when it is determined that the peak value of the phase difference data included in the first frequency band is greater than the first threshold value T1, the vibration part identification unit 100 identifies the part (gear mounting shaft 38) having the natural vibration frequency corresponding to the first frequency band as the vibration part. In addition, in the determination step, for example, when it is determined that the peak value of the phase difference data included in the second frequency band is greater than the second threshold value T2, the vibration part identification unit 100 identifies the part (tool mounting shaft 56) having the natural vibration 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 related to the vibration part identified by the vibration part identification unit 100. Based on this, the user can understand the vibration part and can therefore perform appropriate processing such as finding out the cause of the vibration. Thereafter, the process moves to step S9.

[0052] In step S9, the control unit 88 stops the driving of the grinding system 10. Figure 3 The processing is completed.

[0053] When it is determined in the determination step that the grinding of the workpiece tooth surface 62 does not produce an abnormality (No in step S6), transfer to step S10. In step S10, the determination unit 96 determines whether the grinding of all the workpieces 12 has been completed. In other words, the determination unit 96 determines whether the grinding of a predetermined number of workpieces 12 (for example, N workpieces 12) has been completed. In the case where it is determined by the determination unit 96 that the grinding of all the workpieces 12 is not completed (No in step S10), transfer to step S1. In the case where it is determined by the determination unit 96 that the grinding of all the workpieces 12 has been completed (Yes in step S10), after the processing of step S9 is performed, Figure 3 The processing is completed.

[0054] According to this embodiment, whether 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 an abnormality has occurred in the grinding of the workpiece tooth surface 62. Consequently, a more advanced grinding system 10 and a method for controlling the grinding system 10 can be provided.

[0055] The following supplementary notes are also disclosed regarding the above-mentioned embodiment.

[0056] (Note 1) The grinding system (10) of the present invention has a grinding device (11) for grinding a workpiece tooth surface (62) of the workpiece with a spiral grinding tooth surface (66) of the grinding tool by meshing and synchronously rotating a gear-shaped workpiece (12) and a grinding tool (14). The grinding system has an information acquisition unit (92) and a judgment unit (96), wherein the information acquisition unit acquires information indicating a synchronization error between the workpiece and the grinding tool during the grinding of the workpiece tooth surface; and the judgment unit judges whether an abnormality occurs in the grinding of the workpiece tooth surface based on the synchronization error.

[0057] With this structure, whether an abnormality has occurred in the 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 if an abnormality has occurred in the grinding of the workpiece tooth surface. Consequently, a more advanced grinding system and grinding system control method can be provided.

[0058] (Note 2) In the grinding system described in Note 1, the information acquisition unit may acquire phase difference data between the rotational phase of the workpiece detected by the first encoder (68) and the rotational phase of the grinding tool detected by the second encoder (70) as the information representing the synchronization error.

[0059] According to such a configuration, information on synchronization errors can be easily acquired.

[0060] (Note 3) In the grinding system described in Note 2, it may be possible to further include an analysis unit (94) which obtains analysis data by performing frequency analysis on the phase difference data, and when the peak value of the phase difference data contained in a predetermined frequency band in the analysis data obtained by the analysis unit is above a predetermined threshold value (T1, T2) of the frequency band, the determination unit determines that the abnormality has occurred.

[0061] According to such a configuration, by using the peak value of the phase difference data included in a specific frequency band, it is possible to accurately determine whether an abnormality has occurred in the grinding of the workpiece tooth surface.

[0062] (Note 4) In the grinding system described in Appendix 3, the frequency band can be determined based on the natural vibration frequency of the part of the grinding device where vibration is assumed to occur. The grinding system also has a vibration part specifying unit (100) that specifies the vibration part of the grinding device based on the judgment result when the judgment unit determines that the abnormality has occurred.

[0063] According to this structure, when a specific part of the grinding device vibrates and causes abnormal grinding of the workpiece tooth surface, the vibrating part can be easily identified. This allows the user to understand the vibrating part and take appropriate measures.

[0064] (Note 5) The grinding system according to 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.

[0065] According to such a configuration, appropriate processing such as removing a product gear having a grinding abnormality from a production line can be performed based on the abnormality signal outputted from the signal output unit.

[0066] (Note 6) The grinding system in the control method of the grinding system of the present invention has a grinding device for grinding the workpiece tooth surface of the workpiece with the spiral grinding tooth surface of the grinding tool by making the gear-shaped workpiece and the grinding tool mesh and rotate synchronously. The control method of the grinding system has an information acquisition step and a judgment step, wherein in the information acquisition step, information representing the synchronization error between the workpiece and the grinding tool during the grinding of the workpiece tooth surface is acquired; in the judgment step, whether an abnormality occurs in the grinding of the workpiece tooth surface is determined based on the synchronization error.

[0067] According to such a method, the same effects as those of Supplementary Note 1 are achieved. Therefore, a more excellent method for controlling a grinding system can be provided.

[0068] (Note 7) In the control method of the grinding system described in Note 6, in the information acquisition step, phase difference data between the rotation phase of the workpiece detected by the first encoder and the rotation phase of the grinding tool detected by the second encoder may be acquired as information representing the synchronization error.

[0069] According to this method, the same effect as Supplementary Note 2 is achieved.

[0070] (Note 8) In the control method of the grinding system described in Note 7, it can be that in the judgment step, when the peak value of the phase difference data contained in a predetermined frequency band in the analysis data obtained by performing frequency analysis on the phase difference data is above a predetermined threshold value of the frequency band, it is judged that the abnormality has occurred.

[0071] According to this method, the same effect as Supplementary Note 3 is achieved.

[0072] (Note 9) In the control method for a grinding system described in Supplementary Note 8, the frequency band may be determined based on the natural vibration frequency of a portion of the grinding device where vibration is assumed to occur. The control method for the grinding system may further include a vibration portion specifying step. In this vibration portion specifying step, when it is determined in the determination step that the abnormality has occurred, the vibration portion of the grinding device is specified based on the frequency band including the peak value exceeding the threshold value.

[0073] According to this method, the same effect as Supplementary Note 4 is achieved.

[0074] (Note 10) The method for controlling a grinding system according to any one of Supplementary Notes 6 to 9 may further include a signal output step of outputting an abnormality signal indicating the abnormality when the abnormality is determined to have occurred in the determination step.

[0075] According to this method, the same effect as Supplementary Note 5 is achieved.

[0076] Although the present invention has been described in detail, the present invention is not limited to the above-mentioned embodiments. These embodiments can be variously added, replaced, changed, partially deleted, etc. without departing from the scope of the main purpose of the present invention, or without departing from the scope of the main purpose of the present invention derived from the contents recorded in the technical solution and its equivalents. In addition, these embodiments can also be implemented in combination. For example, in the above-mentioned embodiment, the order of each action and the order of each processing are shown as an example and are not limited to this. In addition, the same applies to the case where numerical values ​​or formulas are used in the description of the above-mentioned embodiment.

Claims

1. A grinding system comprising a grinding device for grinding a tooth surface of a gear-shaped workpiece with a grinding tool by meshing and rotating the workpiece and the grinding tool in synchronization with the workpiece, It is characterized by: It has an information acquisition unit and a determination unit, wherein The information acquisition unit acquires information indicating a synchronization error between the workpiece and the grinding tool during grinding of the tooth surface of the workpiece; The determination unit determines whether an abnormality has occurred in the grinding of the workpiece tooth surface based on the synchronization error.

2. The grinding system according to claim 1, characterized in that The information acquisition unit acquires phase difference data between a rotation phase of the workpiece detected by a first encoder and a rotation phase of the grinding tool detected by a second encoder as the information indicating the synchronization error.

3. The grinding system according to claim 2, characterized in that It also includes an analysis unit that performs frequency analysis on the phase difference data to obtain analysis 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 in the analysis data obtained by the analysis unit is equal to or greater than a predetermined threshold value in the frequency band.

4. The grinding system according to claim 3, characterized in that The frequency band is determined based on the natural frequency of the portion of the grinding device where vibration is assumed to occur. The grinding system further includes a vibration site identifying unit that identifies a vibration site of the grinding device based on a determination result when the determination unit determines that the abnormality has occurred.

5. The grinding system according to any one of claims 1 to 4, characterized in that The device further includes a signal output unit that outputs an abnormality signal indicating the abnormality when the determination unit determines that the abnormality has occurred.

6. A method for controlling a grinding system, wherein the grinding system includes a grinding device for grinding a tooth surface of a gear-shaped workpiece with a helical grinding tooth surface of the grinding tool by meshing and synchronously rotating the workpiece and the grinding tool. It is characterized by: It has an information acquisition step and a determination step, wherein: In the information acquisition step, information representing a synchronization error between the workpiece and the grinding tool during the grinding of the tooth surface of the workpiece is acquired; In the determination step, it is determined whether an abnormality occurs in the grinding of the tooth surface of the workpiece based on the synchronization error.

7. The control method of the grinding system according to claim 6, characterized in that: In the information acquisition step, phase difference data between the rotation phase of the workpiece detected by the first encoder and the rotation phase of the grinding tool detected by the second encoder is acquired as information indicating the synchronization error.

8. The control method of the grinding system according to claim 7, characterized in that: 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 in 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.

9. The control method of the grinding system according to claim 8, characterized in that: The frequency band is determined based on the natural frequency of the portion of the grinding device where vibration is assumed to occur. The method further includes a vibration location identifying step of identifying a vibration location of the grinding device based on the frequency band including the peak exceeding the threshold value when the determination step determines that the abnormality has occurred.

10. The method for controlling a grinding system according to any one of claims 6 to 9, characterized in that: The method further includes a signal output step of outputting an abnormality signal indicating the abnormality when the determination step determines that the abnormality has occurred.

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