Gear grinding machine and gear grinding method
The gear grinding machine and method improve machining accuracy and efficiency by measuring end faces and setting precise tool-workpiece movements to account for tolerances, reducing air cut and overcut, and thus shortening machining time.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- JTEKT CORP
- Filing Date
- 2025-01-08
- Publication Date
- 2026-07-21
Smart Images
Figure 2026120022000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a gear grinding machine and a gear grinding method.
Background Art
[0002] In a gear grinding machine that grinds a workpiece with a helical grinding wheel, when forming a gear tooth surface on the workpiece, it is necessary to align the tool and the workpiece to set a reference position for the machining operation. Conventionally, as the reference position of the machining operation, for example, the tooth width center position of the workpiece held by the jig is calculated from the position of a reference surface preset in the jig for gripping the workpiece and the design value of the tooth width of the gear. Also, in the configuration disclosed in Patent Document 1, the reference position of the machining operation is set based on the deviation amount between the results of measuring a plurality of positions on the tooth surface of the workpiece and a reference involute shape.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] However, since the shape of the workpiece includes tolerances, if the reference position for machining is set using the design value of the gear tooth width, as in the conventional configuration, the reference position for machining will be shifted by the tolerance. Also, even if the reference position for machining is set based on the position of a point on the tooth surface, as in the configuration disclosed in Patent Document 1, the reference position for machining will include the tolerance shift of the workpiece shape. Therefore, in either case, there is room for improvement in improving the machining accuracy of the tooth surface formed on the workpiece. Furthermore, because the reference position for machining is shifted by the tolerance, it is necessary to ensure that the air cut amount, which is the amount of movement before the tool contacts the workpiece, and the overcut amount, which is the amount of movement after the tool moves away from the workpiece, are large enough to take the tolerance into account, which increases the machining time.
[0005] This invention has been made in view of the above problems, and aims to provide a gear grinding machine and a gear grinding method that can improve the machining accuracy of the tooth surface and shorten the machining time. [Means for solving the problem]
[0006] One aspect of the present invention is, A gear grinding machine that grinds a workpiece having a gear portion with multiple teeth formed on its circumferential surface and a shaft portion connected to the center of the gear portion with a tool to form tooth surfaces on the gear portion, A workpiece spindle head that grips the shaft portion and supports the workpiece so that it can rotate, A tool spindle that rotatably holds the aforementioned tool, An end face position measuring unit for measuring the position of at least one of a pair of end faces in the tooth width direction of the gear portion of the workpiece supported on the workpiece headstock, or the position of at least one of a pair of end faces in the axial direction of the shaft portion, A machining operation reference calculation unit calculates a machining operation reference, which is the reference position for the machining operation of the grinding process by the tool, based on the measurement results of the end face position measuring unit. A machining operation setting unit sets a machining operation, which is the relative movement between the tool and the workpiece, based on the machining operation reference and the desired shape of the tooth surface to be formed on the workpiece. A control unit controls the operation of the tool spindle and the workpiece spindle head based on the machining operation set by the machining operation setting unit to grind the tooth surface of the workpiece. It is located in a gear grinding machine equipped with [this feature].
[0007] Other aspects of the present invention include: A gear grinding method for forming tooth surfaces on a gear portion having a gear portion with multiple teeth formed on its circumferential surface and a shaft portion connected to the center of the gear portion, wherein the workpiece is ground with a tool to form tooth surfaces on the gear portion, An end face position measuring step for measuring the position of at least one of a pair of end faces in the tooth width direction of the gear portion, or the position of at least one of a pair of end faces in the axial direction of the shaft portion, in the workpiece which is rotatably supported by gripping the shaft portion with the workpiece headstock, A machining operation reference calculation step calculates a machining operation reference, which is the reference position of the machining operation of the grinding operation performed by the tool rotatably held on the tool spindle, based on the measurement results in the end face position measurement step. A machining operation setting step, which sets a machining operation that is the relative movement between the tool and the workpiece, based on the machining operation reference and the target shape of the tooth surface to be formed on the workpiece, A gear grinding method comprising a grinding step of grinding the tooth surface of a workpiece by controlling the operation of the tool spindle and the workpiece spindle head based on the machining operation set in the machining operation setting step. It is located there. [Effects of the Invention]
[0008] According to the gear grinding machine of the above embodiment, the position of at least one of a pair of end faces in the tooth width direction of the gear portion or the position of at least one of a pair of end faces in the axial direction of the shaft portion of the workpiece supported on the workpiece headstock is measured, and a machining operation standard is calculated based on the measurement result. As a result, the machining operation standard is calculated taking into account the tolerance of the workpiece, and the tooth surface formed by the machining operation set according to the machining operation standard and the target shape exhibits high machining accuracy. Furthermore, the machining operation set according to the machining operation standard and the target shape can reduce the air cut amount, which is the amount of movement before the tool contacts the workpiece, and the overcut amount, which is the amount of movement after the tool moves away from the workpiece, thereby shortening the machining time.
[0009] According to the gear grinding method of the other embodiment described above, the position of at least one of a pair of end faces in the tooth width direction of the gear portion or the position of at least one of a pair of end faces in the axial direction of the shaft portion of the workpiece supported on the workpiece headstock is measured, and a machining operation standard is calculated based on the measurement result. As a result, the machining operation standard is calculated taking into account the tolerance of the workpiece, and the tooth surface formed by the machining operation set according to the machining operation standard and the target shape exhibits high machining accuracy. Furthermore, the machining operation set according to the machining operation standard and the target shape can reduce the air cut amount, which is the amount of movement before the tool contacts the workpiece, and the overcut amount, which is the amount of movement after the tool moves away from the workpiece, thereby shortening the machining time.
[0010] As described above, according to the above embodiment, it is possible to provide a gear grinding machine and a gear grinding method that can improve the machining accuracy of the tooth surface and shorten the machining time. [Brief explanation of the drawing]
[0011] [Figure 1] This is a conceptual diagram illustrating the configuration of the gear grinding machine according to Embodiment 1. [Figure 2] This is a conceptual diagram illustrating the first measurement mode of the end face position measuring unit of Embodiment 1. [Figure 3] It is a conceptual diagram for explaining the second measurement mode of the end face position measurement unit of Embodiment 1. [Figure 4] It is a conceptual diagram for explaining the third measurement mode of the end face position measurement unit of Embodiment 1. [Figure 5] (a) It is a conceptual diagram showing a reference involute shape, and (b) to (d) are conceptual diagrams showing elements of tooth surface finishing with respect to the reference involute shape. [Figure 6] It is a conceptual diagram showing the machining operation standard in Embodiment 1. [Figure 7] It is a conceptual diagram showing the start position of the machining operation in Embodiment 1. [Figure 8] It is a conceptual diagram showing the end position of the machining operation in Embodiment 1. [Figure 9] It is a flowchart of the gear grinding method of Embodiment 1. [Figure 10] It is a conceptual diagram for explaining the configuration of the gear grinding machine of Embodiment 2. [Figure 11] It is a flowchart of the gear grinding method of Embodiment 2.
Mode for Carrying Out the Invention
[0012] (Embodiment 1) 1. Gear grinding machine 1 The gear grinding machine 1 of Embodiment 1 will be described with reference to FIG. 1. The gear grinding machine 1 is a gear grinding machine that grinds the peripheral surface of the gear portion Wa of the workpiece W with the tool T to form a tooth surface on the gear portion Wa. The workpiece W to be processed includes a gear portion Wa and a shaft portion Wb connected to the center of the gear portion Wa, and a plurality of teeth are formed on the peripheral surface of the gear portion Wa by the gear grinding machine 1. The gear portion Wa has a disk shape or a columnar shape, and the shaft portion Wb has a rod shape. The gear portion Wa may be a spur gear or a helical gear. As shown in FIG. 1, the gear grinding machine 1 includes a workpiece spindle base 10, a tool spindle 20, an end face position measurement unit 30, a machining operation standard calculation unit 40, a machining operation setting unit 50, a control unit 60, and an input unit 70. Each configuration will be described in detail below.
[0013] 1-1. Workpiece spindle base 10 The workpiece headstock 10 shown in Figure 1 grips the shaft portion Wb of the workpiece W and supports the workpiece so that it can rotate. In this embodiment 1, the lower end of the shaft portion Wb is gripped so that the axial direction of the shaft portion Wb is vertical. The axis of rotation C of the rotational movement of the workpiece W by the workpiece headstock 10 coincides with the axis of the shaft portion Wb. In this embodiment 1, the vertical direction is defined as the Z direction, the direction perpendicular to the Z direction and in which the tool T (described later) and the workpiece W face each other is defined as the X direction, and the direction perpendicular to the Z direction and the X direction is defined as the Y direction. A motor (not shown) is mounted on the workpiece headstock 10, and the rotation phase of the workpiece W can be controlled by the control unit 60 (described later) which controls the drive of the motor. Note that the direction of the shaft portion Wb by the workpiece headstock 10 is not limited to the vertical direction, but may also be horizontal or inclined.
[0014] 1-2. Tool spindle 20 The tool spindle 20 shown in Figure 1 rotatably supports the tool T. The type of tool T is not limited as long as it is a tool capable of grinding, but in this embodiment 1, the tool T is a screw-shaped grinding wheel. The tool spindle 20, which holds the tool T, is connected to the tool headstock 21, and the tool T rotates as the tool spindle 20 rotates around the A axis, which is the central axis of the tool spindle 20, by a motor (not shown) provided on the tool headstock 21. The rotation speed of the tool T is controlled by a control unit 60, which will be described later.
[0015] Furthermore, the tool headstock 21 is equipped with a motor (not shown), which allows it to move in the X and Y directions. It can also rotate around the B axis, which has the Y direction as its axis. The movement in the X and Y directions and the rotation phase of the A axis are controlled by the control unit 60, which will be described later.
[0016] 1-3. End face position measurement section 30 The end face position measuring unit 30 shown in Figure 1 measures the position of at least one of a pair of end faces in the tooth width direction of the gear portion Wa of the workpiece W supported by the workpiece headstock 10, or the position of at least one of a pair of end faces in the axial direction of the shaft portion Wb. The end face position measuring unit 30 is composed of a contact type or a non-contact type position sensor. In this embodiment 1, the end face position measuring unit 30 is a contact type position sensor equipped with a sensor head 31. The end face position measuring unit 30 is provided on the tool headstock 21 such that the sensor head 31 protrudes toward the workpiece W held by the workpiece headstock 10.
[0017] In this embodiment 1, as shown in Figure 2, the end face position measuring unit 30 detects the position of end face Wa1 by bringing the sensor head 31 into contact with one of the pair of end faces Wa1 and Wa2 in the tooth width direction of the gear portion Wa on the workpiece W. Furthermore, as shown in Figure 3, the end face position measuring unit 30 detects the position of end face Wa2 by bringing the sensor head 31 into contact with the other end face Wa2. The detected position information is stored in a memory (not shown) provided in the arithmetic unit 2, which will be described later.
[0018] In addition, instead of detecting the position of both or one of the pair of end faces Wa1 and Wa2 in the tooth width direction of the gear portion Wa, the end face position measuring unit 30 may measure the position of one of the pair of end faces Wb1 and Wb2 in the axial direction of the shaft portion Wb, as shown in Figure 4. Also, although not shown, if the other end face Wb2 of the pair of end faces Wb1 and Wb2 in the axial direction of the shaft portion Wb is in a measurable position, the position of the other end face Wb2 may be measured instead.
[0019] 1-4. Machining operation standard calculation unit 40 The machining operation reference calculation unit 40 shown in Figure 1 calculates the machining operation reference L1, which is the reference position for the machining operation of grinding by the tool T, based on the measurement results of the end face position measuring unit. The machining operation reference calculation unit 40 is realized by executing a predetermined program on a computing device 2, which includes a computer and memory (not shown).
[0020] The machining operation reference calculation unit 40 can calculate the machining operation reference L1 according to the tooth surface modification elements set based on the target shape of the tooth surface to be formed on the workpiece W and the reference involute shape. In this embodiment 1, the tooth surface modification elements are tooth surface modifications in the tooth trace direction and include one or more combinations of tooth trace crowning modification shown by reference numeral 16 in Figure 5(b), bias modification shown by reference numeral 16 in Figure 5(c), and end relief shown by reference numeral 16 in Figure 5(d). If the target shape matches the reference involute shape shown by reference numeral 15 in Figure 5(a), the tooth surface modification is set to none, and the machining operation reference L1 can be calculated based on this.
[0021] In this embodiment 1, the machining operation reference calculation unit 40 calculates the central position in the tooth width direction (Z direction) as the machining operation reference L1, for example, in accordance with tooth trace crowning correction, as shown in Figure 6. Since tooth trace crowning correction is a correction that causes the central position in the tooth width direction (Z direction) to bulge relative to the reference involute shape, the accuracy of the correction can be improved by setting the central position in the tooth width direction as the machining operation reference L1. Note that other positions may be calculated instead of the central position in the tooth width direction as the machining operation reference L1.
[0022] Furthermore, if the position of the other end face Wa2 in the tooth width direction of the gear part Wa or the position of the other end face Wb2 in the axial direction of the shaft part Wb is not in a detectable position, the machining operation reference calculation unit 40 can also calculate the machining operation reference L1 based on the workpiece headstock reference position L2 set on the workpiece headstock 10 shown in Figure 6 and the position of one end face Wa1 in the tooth width direction of the gear part or the position of one end face Wb2 in the axial direction of the shaft part Wb, which are included in the measurement results of the end face position measurement unit 30.
[0023] 1-5. Machining operation setting section 50 The machining operation setting unit 50 shown in Figure 1 sets the machining operation, which is the relative movement between the tool T and the workpiece W, based on the machining operation reference L1 and the desired shape of the tooth surface to be formed on the workpiece W. The machining operation setting unit 50 is realized by executing a predetermined program on the calculation unit 2.
[0024] The machining operation setting unit 50 sets time-series data of the position of the tool T in the X, Y, and Z directions, the rotational phase of the B axis, and the rotational phase of the workpiece W as machining operations. The machining operations may also include information on the rotational speed of the tool T. The machining operations reflect the tooth surface modification set according to the target shape.
[0025] In this embodiment 1, the machining operation setting unit 50 sets the start and end positions of the machining operation. In this embodiment 1, the machining operation generally follows the arrow P shown in Figure 1. For example, as the start position of the machining operation, the position of the tool T can be set near one end face Wa1 of the gear part Wa, as shown in Figure 7, and as the end position of the machining operation, the position of the tool T can be set near the other end face Wa2 of the gear part Wa, as shown in Figure 8. If the tooth trace of the target shape has a helix angle, the machining operation can be tilted with respect to the Z direction according to the helix angle.
[0026] 1-6. Control Unit 60 The control unit 60 shown in Figure 1 controls the operation of the tool spindle 20 and the workpiece headstock 10 based on the machining operation set by the machining operation setting unit 50 to grind the tooth surface of the workpiece W. The control unit 60 is implemented by CNC (Computer Numerical Control), which causes the calculation unit 2 to execute a predetermined program and numerically controls the drive of various motors provided on the tool spindle 20 and the workpiece headstock 10 according to the machining operation.
[0027] 1-7. Input section 70 The input unit 70 shown in Figure 1 allows the user to input the desired shape of the tooth surface, machining conditions, etc.
[0028] 2. Gear grinding method in Embodiment 1 Next, the gear grinding method in this embodiment 1 will be described with reference to the flowchart shown in Figure 9. In this gear grinding method, first, in step S1 shown in Figure 9, a gripping step S1 is performed in which the shaft portion Wb of the workpiece W is gripped by the workpiece headstock 10 and the workpiece W is supported so that it can rotate.
[0029] Subsequently, in step S2, the end face position measuring unit 30 performs an end face position measuring step S2, which measures the position of at least one of the pair of end faces Wa1 and Wa2 in the tooth width direction of the gear portion Wa on the workpiece W held by the workpiece headstock 10, or the position of at least one of the pair of end faces Wb1 and Wb2 in the axial direction of the shaft portion Wb. In this embodiment 1, as shown in Figures 3 and 4, the positions of both the pair of end faces Wa1 and Wa2 in the tooth width direction of the gear portion Wa are measured. The measurement results are stored in a memory (not shown) of the arithmetic unit 2.
[0030] Next, the process proceeds to step S3 in Figure 9, where the machining operation reference calculation unit 40 calculates the machining operation reference L1, which is the reference position for the grinding operation by the tool T rotatably held on the tool spindle 20, based on the measurement results of the end face position measuring unit 30. This is the machining operation reference calculation step S3. In this embodiment 1, as shown in Figure 6, the central position in the tooth width direction of the gear Wa is calculated as the machining operation reference L1.
[0031] Then, in step S4 of Figure 9, the machining operation setting unit 50 performs a machining operation setting step S4, which sets the machining operation, which is the relative movement between the tool T and the workpiece W, based on the machining operation reference L1 and the desired shape of the tooth surface to be formed on the workpiece W. The desired shape of the tooth surface is entered in advance by the user into the input unit 70. Furthermore, in step S5 of Figure 9, the machining operation setting unit 50 performs a start and end position setting step S5, which sets the start and end positions of the machining operation.
[0032] Subsequently, the process proceeds to step S6 in Figure 9, where the control unit 60 controls the operation of the tool spindle 20 and the workpiece spindle head 10 based on the machining operation set by the machining operation setting unit 50 to perform a grinding process S6 in which the tooth surface of the workpiece W is ground. The grinding is performed by moving the tool T from the start position to the end position of the machining operation set by the machining operation setting unit 50. The machining operation may be repeated multiple times. The flow ends upon completion of the grinding process.
[0033] 3. Effects of the gear grinding machine 1 and gear grinding method of Embodiment 1 According to the gear grinding machine 1 and gear grinding method of this embodiment 1, the position of at least one of the pair of end faces Wa1 and Wa2 in the tooth width direction of the gear portion Wa of the workpiece W supported on the workpiece headstock 10, or the position of at least one of the pair of end faces Wb1 and Wb2 in the axial direction of the shaft portion Wb is measured, and the machining operation standard L1 is calculated based on the measurement results. As a result, the machining operation standard L1 is calculated taking into account the tolerance of the workpiece W, and the tooth surface formed by the machining operation set according to the machining operation standard L1 and the target shape exhibits high machining accuracy. Furthermore, since the machining operation set according to the machining operation standard L1 and the target shape can reduce the amount of air cut and the amount of overcut, the machining time can be shortened.
[0034] Furthermore, in this embodiment 1, the machining operation reference calculation unit 40 calculates the central position in the tooth width direction of the gear portion Wa as the machining operation reference L1. This makes it possible to set the machining operation with high precision based on the machining operation reference L1.
[0035] Furthermore, in this embodiment 1, the machining operation reference calculation unit 40 can calculate the machining operation reference L1 based on the workpiece headstock reference position L2 set on the workpiece headstock 10 and the position of one end face Wa1 in the tooth width direction of the gear portion or the position of one end face Wb1 in the axial direction of the shaft portion Wb, which are included in the measurement results of the end face position measurement unit 30. In this case, even if it is difficult to measure the position of the other end face Wa2 in the tooth width direction of the gear portion Wa or the position of the other end face Wb2 in the axial direction of the shaft portion Wb, the machining operation reference L1 can be calculated considering the tolerance of the workpiece W, thereby expanding the range of application of the gear grinding machine 1 and gear grinding method of this embodiment.
[0036] Furthermore, in this embodiment 1, the machining operation reference calculation unit 40 calculates the machining operation reference L1 according to the elements of tooth surface modification relative to the reference involute shape in the target shape of the tooth surface of the workpiece W. This makes it possible to further improve the machining accuracy of the tooth surface.
[0037] Furthermore, in this embodiment 1, the elements of tooth surface modification include at least one of tooth trace crowning modification, bias modification, and end relief. As a result, since the tooth surface modification is a modification in the direction of the tooth trace, the influence of the machining operation is strongly reflected, and the effect of improving the machining accuracy of the tooth surface by the gear grinding machine 1 and gear grinding method of this embodiment is further demonstrated.
[0038] Furthermore, in this embodiment 1, the machining operation setting unit 50 sets the position of one of the pair of end faces Wa1 in the tooth width direction of the tooth surface of the workpiece W as the starting position of the machining operation, and sets the position of the other end face Wa2 in the tooth width direction of the tooth surface of the workpiece W as the ending position of the machining operation. This further reduces the amount of air cut and the amount of overcut, thereby shortening the machining time. In this embodiment 1, an example is shown where one end face Wa1 in the tooth width direction of the tooth surface of the workpiece W is located above in the Z direction and the other end face Wa2 is located below in the Z direction, but it is also possible to have one end face Wa1 located below in the Z direction and the other end face Wa2 located above in the Z direction.
[0039] As described above, this embodiment 1 provides a gear grinding machine 1 and a gear grinding method that can improve the machining accuracy of the tooth surface and shorten the machining time.
[0040] (Embodiment 2) The gear grinding machine 1 of this second embodiment includes, in addition to the configuration of the first embodiment, a tilt calculation unit 80 and a tilt determination unit 81, as shown in Figure 10. The tilt calculation unit 80 and the tilt determination unit 81 are realized by executing a predetermined program on the arithmetic unit 2.
[0041] 4. Inclination calculation unit 80 and inclination determination unit 81 The tilt calculation unit 80 shown in Figure 10 calculates the tilt of the workpiece W on the workpiece spindle head 10 based on the measurement results of the end face position measuring unit 30. The tilt determination unit 81 determines whether the tilt of the workpiece W is within a preset tolerance range. The tolerance range can be set as appropriate.
[0042] 5. Gear grinding method in Embodiment 2 Next, the gear grinding method in this embodiment 2 will be described with reference to the flowchart shown in Figure 11. Steps S1 and S2 in the gear grinding method in this embodiment 2, as shown in Figure 11, are the same as steps S1 and S2 in embodiment 1 shown in Figure 9.
[0043] In this second embodiment, after step S2 shown in Figure 11, the process proceeds to step S21, in which the inclination calculation unit 80 performs an inclination calculation step S21 in which it calculates the inclination of the workpiece W on the workpiece spindle head 10 based on the measurement results of the end face position measuring unit 30.
[0044] Subsequently, in step S22, the tilt determination unit 81 performs a tilt determination step S22 to determine whether the tilt of the workpiece W is within a preset allowable range. If it is determined in step S22 that the tilt of the workpiece W is not within the allowable range, the process proceeds to step S22 No., and steps S1 onwards are repeated.
[0045] On the other hand, if it is determined in step S22 that the tilt of the workpiece W is within an acceptable range, the process proceeds to Yes in step S22, and steps S3 to S6 shown in Figure 11 are performed in the same way as steps S3 to S6 in Embodiment 1 shown in Figure 9. Then, the flow is terminated.
[0046] 6. Effects of the gear grinding machine 1 and gear grinding method of Embodiment 2 According to the gear grinding machine 1 and gear grinding method of this second embodiment, the inclination of the workpiece W held in the workpiece headstock 10 is calculated, and grinding is performed in the same manner as in the first embodiment when the inclination of the workpiece W is within the allowable range. This prevents grinding from being performed with the workpiece W in an unintended inclination when it was held. As a result, a decrease in machining accuracy caused by the unintended inclination of the workpiece W can be prevented. This second embodiment also provides the same effects as the first embodiment.
[0047] The present invention is not limited to the above embodiments 1 and 2, and can be applied to various embodiments without departing from its spirit. [Explanation of symbols]
[0048] 1. Gear grinding machine 10 Workpiece spindle head 20 Tool spindle 21 Tool headstock 30 Edge position measurement section 40 Machining operation standard calculation section 50 Machining operation setting section 60 Control Unit 70 Input section 80. Slope calculation unit 81 Tilt determination unit
Claims
1. A gear grinding machine that grinds a workpiece having a gear portion with multiple teeth formed on its circumferential surface and a shaft portion connected to the center of the gear portion with a tool to form tooth surfaces on the gear portion, A workpiece spindle head that grips the shaft portion and supports the workpiece so that it can rotate, A tool spindle that rotatably holds the aforementioned tool, An end face position measuring unit for measuring the position of at least one of a pair of end faces in the tooth width direction of the gear portion of the workpiece supported on the workpiece headstock, or the position of at least one of a pair of end faces in the axial direction of the shaft portion, A machining operation reference calculation unit calculates a machining operation reference, which is the reference position for the machining operation of the grinding process by the tool, based on the measurement results of the end face position measuring unit. A machining operation setting unit sets a machining operation, which is the relative movement between the tool and the workpiece, based on the machining operation reference and the desired shape of the tooth surface to be formed on the workpiece. A control unit controls the operation of the tool spindle and the workpiece spindle head based on the machining operation set by the machining operation setting unit to grind the tooth surface of the workpiece. A gear grinding machine equipped with [a specific feature].
2. The gear grinding machine according to claim 1, wherein the processing operation reference calculation unit calculates the central position in the tooth width direction of the gear portion as the processing operation reference.
3. The gear grinding machine according to claim 1 or 2, wherein the machining operation reference calculation unit calculates the machining operation reference based on the workpiece headstock reference position set on the workpiece headstock and the position of one end face in the tooth width direction of the gear portion or the position of one end face in the axial direction of the shaft portion included in the measurement results of the end face position measuring unit.
4. The gear grinding machine according to claim 1 or 2, wherein the processing operation reference calculation unit calculates the processing operation reference according to the elements of tooth surface modification with respect to the reference involute shape in the target shape of the tooth surface.
5. The gear grinding machine according to claim 4, wherein the elements of tooth surface modification include at least one of tooth trace crowning modification, bias modification, and end relief.
6. The gear grinding machine according to claim 1 or 2, wherein the machining operation setting unit sets the position of one of a pair of end faces of the tooth surface in the tooth width direction as the starting position of the machining operation, and sets the position of the other end face of the tooth surface in the tooth width direction as the ending position of the machining operation.
7. An inclination calculation unit calculates the inclination of the workpiece on the workpiece spindle head based on the measurement results of the end face position measuring unit, An inclination determination unit that determines whether the inclination of the workpiece is within a preset allowable range, A gear grinding machine according to claim 1 or 2, comprising:
8. A gear grinding method for forming tooth surfaces on a gear portion having a gear portion with multiple teeth formed on its circumferential surface and a shaft portion connected to the center of the gear portion, wherein the workpiece is ground with a tool to form tooth surfaces on the gear portion, An end face position measuring step for measuring the position of at least one of a pair of end faces in the tooth width direction of the gear portion, or the position of at least one of a pair of end faces in the axial direction of the shaft portion, in the workpiece which is rotatably supported by gripping the shaft portion with the workpiece headstock, A machining operation reference calculation step calculates a machining operation reference, which is the reference position of the machining operation of the grinding operation performed by the tool rotatably held on the tool spindle, based on the measurement results in the end face position measurement step. A machining operation setting step, which sets a machining operation that is the relative movement between the tool and the workpiece, based on the machining operation reference and the desired shape of the tooth surface to be formed on the workpiece, A gear grinding method comprising a grinding step of grinding the tooth surface of a workpiece by controlling the operation of the tool spindle and the workpiece spindle head based on the machining operation set in the machining operation setting step.