Gear component machining method, program and machining device

Abstract

The present invention relates to a gear component machining method, a program thereof, and a machining device capable of precisely machining a non-toothed portion. The machining method according to the present invention includes a step of gripping a columnar workpiece having a toothed portion machined on a portion of a circumference along the axial direction with the workpiece spindle so that the axis is aligned with the rotary machining axis, measuring the toothed portion to calculate the deviation of the center axis of the toothed portion from the rotary machining axis, and machining the workpiece eccentrically from the other end side with respect to the rotary machining axis based on the deviation. The program includes a step of gripping a columnar workpiece having a toothed portion machined on a portion of a circumference along the axial direction with the workpiece spindle so that the axis is aligned with the rotary machining axis with the workpiece spindle measuring the toothed portion, calculating the deviation of the center axis of the toothed portion from the rotary machining axis from the measured value, and machining the workpiece eccentrically from the other end side with respect to the rotary machining axis based on the calculated deviation. The machining device includes a first workpiece spindle, a tool holding device, a moving device, and a control device for controlling the driving of these devices, and follows the machining program described above.

Description

[Technical field]

[0001] The present invention relates to a method, a program and a processing device for machining gear components, and more particularly to a method, a program and a processing device for machining gear components that processes non-tooth cutting portions. [Background technology]

[0002] A known gear cutting process involves pressing a rotating hob against a rotating workpiece while rotating it to cut a gear. If the rotation axis of the rotary table and the axis of the workpiece do not coincide, the teeth of the gear will be machined eccentrically.

[0003] For example, Patent Document 1 discloses a processing method in which the rotation phase of a rotary table and the cutting depth of a hob cutter are corrected so as to cancel the eccentricity between the rotation axis of the rotary table and the axis of a workpiece in gear cutting using a hob machine. According to this method, it is said that gear cutting can be performed with high precision even on a workpiece that is eccentrically attached. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2011 / 129008 Summary of the Invention [Problem to be solved by the invention]

[0005] By the way, by using a multi-tasking machine, it is possible to attach a hob cutter to perform gear cutting on the circumferential surface of a workpiece to form a gear cutting portion, and then change tools to continue cutting other parts. In this case, if the workpiece is once removed from the workpiece spindle after gear cutting and then reattached to perform rotary cutting, the rotation axis of the workpiece spindle and the central axis of the gear cutting portion of the attached workpiece do not coincide, making it impossible to perform accurate rotary cutting. The same is true when a part that has been machined into gears is attached to a processing machine to perform further rotary cutting.

[0006] An object of the present invention is to provide a gear component machining method, a program therefor, and a machining device that can precisely machine portions other than the gear cutting portion. [Means for solving the problem]

[0007] The method for machining gear parts according to the present invention involves gripping a cylindrical workpiece having a gear cutting portion machined along a portion of the circumference along the axis on one end side of the workpiece by a work spindle so that the axis is aligned with the rotary machining axis, measuring the gear cutting portion and calculating the deviation of the central axis of the gear cutting portion from the rotary machining axis, and performing eccentric machining from the other end side with respect to the rotary machining axis based on this deviation.

[0008] In addition, the machining program according to the present invention measures the gear cutting portion by gripping the workpiece with the work spindle at one end side of a cylindrical workpiece having a gear cutting portion machined on a portion of a circumference along an axis so that the axis is aligned with the rotary machining axis, calculates the deviation of the central axis of the gear cutting portion from the rotary machining axis from the measured measurement value, and performs eccentric machining from the other end side with respect to the rotary machining axis based on the calculated deviation.

[0009] Furthermore, the machining apparatus according to the present invention includes a first work spindle that rotatably grips a workpiece, a tool holding device that holds a measuring instrument or a tool, a moving device that can move the first work spindle and the tool holding device relatively, and a control device that controls the drive of the first work spindle, the tool holding device, and the moving device, and in accordance with a machining program, the first work spindle holds a columnar workpiece having a gear cutting portion machined on a portion of a circumference along the axis at one end side of the workpiece so that the axis is aligned with the rotary machining axis, the measuring instrument held by the tool holding device measures the gear cutting portion, calculates the deviation of the central axis of the gear cutting portion from the rotary machining axis from the measured measurement value, and performs eccentric machining of the workpiece from the other end side of the workpiece with respect to the rotary machining axis based on the calculated deviation using a tool held by the tool holding device.

[0010] According to the above invention, it is possible to precisely machine the portions other than the gear cutting portion. [Brief description of the drawings]

[0011] [Figure 1] 1 is a perspective view (partially a block diagram) of a main part of a processing device in one embodiment according to the present invention. [Diagram 2] 1 is a side cross-sectional view of a workpiece in one embodiment according to the present invention. [Diagram 3] FIG. 2 is a flow diagram illustrating a processing method in one embodiment according to the present invention. [Figure 4A] FIG. 2 is a side view of the columnar material attached to the first work spindle. [Figure 4B] FIG. 2 is a side cross-sectional view of a cylindrical blank to be turned and drilled. [Figure 4C] FIG. 2 is a side cross-sectional view of a columnar material (workpiece) to be machined. [Figure 5A] FIG. 11 is a side cross-sectional view of the workpiece reattached to the first work spindle. [Figure 5B] FIG. 2 is a side cross-sectional view of a workpiece on which tooth pitch measurement is performed. [Figure 5C] FIG. 2 is a side cross-sectional view of a workpiece to be eccentrically machined. [Figure 6A]FIG. 11 is a front view of a workpiece illustrating the misalignment of the central axis in another embodiment. [Figure 6B] FIG. 11 is a front view of a workpiece for explaining correction of deviation of the central axis in another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, a gear component machining method, its program, and machining device according to the present invention will be described in detail with reference to Figs. 1 to 5C.

[0013] First, a processing device used in the gear component processing method will be described.

[0014] As shown in FIG. 1, the processing device 1 is a numerically controlled machine tool that operates according to an input program. Furthermore, it is preferable that the processing device 1 is a multi-tasking machine having an automatic tool changing function. Here, an example is used in which spindle units are provided on the left and right sides of a base 2 as viewed in the drawing (in the explanation of FIG. 1, the left and right sides, the front, etc. are viewed as viewed in the drawing. The same applies to the explanation of each drawing below). Of the left and right spindle units, the left side is a first spindle unit 10 to which a workpiece W is attached, and the right side is a second spindle unit 20. The left first spindle unit 10 includes a workpiece spindle stock 11 and a first workpiece spindle 12, and the first workpiece spindle 12 grips the workpiece W and supports it rotatably around the rotary machining axis C of the first workpiece spindle 12. The right second spindle unit 20 includes a workpiece spindle stock 21 and a second workpiece spindle 22, and can similarly grip the workpiece W and support it rotatably around the rotary machining axis C' of the second workpiece spindle, and is used as needed. The first work spindle 12 and the second work spindle 22 are disposed facing each other, and are provided with a spindle movement mechanism (not shown) that changes the relative distance between them so that the work can be handed over between them. Therefore, the rotary machining axis C and the rotary machining axis C' are disposed to coincide with each other, and the movement by the spindle movement mechanism is along the rotary machining axis C.

[0015] The processing device 1 further includes a column unit 31 that can move horizontally left and right on the base 2. The column unit 31 is attached to the base 2 so as to be movable in parallel left and right along the Z axis, and its position in the Z axis direction is adjusted by a combination of a Z axis servo motor 31a and a Z axis ball screw 31b. A rotating shaft 33 is attached to the front side of the column unit 31 via a combination of an X axis servo motor 32a and an X axis ball screw 32b. This allows the rotating shaft 33 to move in parallel in the X axis direction and the Z axis direction, respectively. The rotating shaft 33 is further rotatable around a rotation axis extending in the Y axis direction, and a tool holding device 33a provided at the tip portion is rotatable around an axis perpendicular to the Y axis. In other words, the tool holding device 33a can be moved relatively to the first work spindle 12 and the second work spindle 22 by a moving device 30 consisting of a series of drive mechanisms including a column unit 31, a Z-axis servo motor 31a, a Z-axis ball screw 31b, a rotating shaft 33, an X-axis servo motor 32a, and an X-axis ball screw 32b.

[0016] Tools 34 are attached to the tool holding device 33a. As the tools 34, measuring instruments such as the touch probe 34a shown here and tools such as cutting tools are used. The touch probe 34a can acquire the coordinates of the contact position with respect to the base 2 by contacting its tip with the surface of the workpiece W, and is used for measuring the dimensions of the workpiece W. The touch probe 34a can also be replaced with a hob cutter described later to cut the workpiece W into a gear to form a gear cutting portion. That is, the tool holding device 33a can be used as a cutting device that cuts the workpiece W or a measuring device that measures the workpiece W by the attached tools 34. An automatic tool changer 45 is provided on the right side of the base 2, and the tool holding device 33a can be moved close to the tool holding device 33a to automatically change the measuring instrument or cutting tool and hold it in the tool holding device 33a.

[0017] The machining device 1 further includes a control device 40 that performs numerical control and can control the driving of the first spindle unit 10, the second spindle unit 20, the moving device 30, the automatic tool changer 45, and the like. The control device 40 includes an input interface (not shown) operated by an operator and is connected to a calculation device 41. The calculation device 41 has at least a memory unit 42 that stores a machining program for gear components and a calculation unit 43. The calculation device 41 sends a signal to the control device 40 to control the operation of the machining device 1 according to the program read from the memory unit 42, and can operate the machining device 1 to perform a machining method for gear components described later. The calculation unit 43 can obtain measurement values ​​such as coordinate data of the workpiece W measured by the touch probe 34a from the control device 40 and calculate a deviation between the center axis A and the rotary machining axis C described later. The calculation device 41 may be built into the control device 40.

[0018] Next, a method for machining a gear component using the machining device 1 will be described.

[0019] As shown in FIG. 2, the gear part to be obtained by machining the workpiece W is a stepped columnar part having a gear cutting part on a part of the circumference in the direction along the axis A', and one end side in the direction along the axis A' is gripped and machined from the other end side after machining of the gear cutting part. Here, a gear part having a stepped cylindrical shape is illustrated as an example, which has a gear cutting part 51 with gear teeth 51a formed on the outer periphery at the center in the left-right direction of the paper, and has shaft-shaped parts 52 and 53 having a substantially cylindrical shape on both the left and right sides. In addition, hole parts 52a and 53a, which are bottomed holes cut from the end faces toward the center, are formed in each of the shaft-shaped parts 52 and 53. The hole parts 52a and 53a are, for example, bearing journals.

[0020] Furthermore, a processing procedure including a processing method for the gear component will be described with reference to FIGS. 4A to 5C along with FIG.

[0021] First, a columnar material W' for obtaining the workpiece W is attached to the first workpiece spindle 12 (S1).

[0022] 4A, the columnar material W' has a gear cutting circumferential portion 51' having a large diameter and a substantially disk-like shape at its center, and cylindrical shaft portions 52 and 53 on both sides. The gear cutting circumferential portion 51' and the shaft portions 52 and 53 have their outer peripheries and side surfaces of steps roughly machined. The first work spindle 12 holds the vicinity of the end of the shaft portion 52 and supports the columnar material W' in a cantilever manner. The central axis A will be described later.

[0023] Next, referring to FIG. 4B, the gear cutting circumferential portion 51' of the columnar material W' is turned, and the shaft-shaped portion 53 on the side of the columnar material W' that is not held, which is one end side of the workpiece W, is turned and then drilled (S2). The turning of the gear cutting circumferential portion 51' is a process for forming a blank for gear cutting, which will be described later, and involves turning the outer circumferential surface and the side surface of the step portion. The turning of the shaft-shaped portion 53 is a finishing process for the shaft-shaped portion 53 of the gear part. In these turning processes, a turning tool 34b is used as the tool 34 held by the tool holding device 33a (see FIG. 1) of the moving device 30, and processing is performed. On the other hand, the drilling of the shaft-shaped portion 53 is a process for forming the hole portion 53a. In such drilling, for example, a pilot hole is formed by cutting using a rotating tool 34c such as a U-drill held by a tool holding device 33a, and then the hole is expanded using an end mill (not shown), or the inner surface is machined using a turning tool.

[0024] Next, referring to FIG. 4C, the outer periphery of the gear cutting circumferential portion 51' is subjected to gear cutting to form a tooth portion 51a, and the workpiece W is obtained from the columnar material W' (S3). Here, the hob cutter 34d is attached to the tool holding device 33a (see FIG. 1) of the moving device 30, and the columnar material W' is rotated around the rotary machining axis C (see FIG. 1) of the first work spindle 12 in synchronization with the rotation of the hob cutter 34d to perform gear cutting. Furthermore, the tooth portion 51a is deburred, and the phase of the formed tooth portion 51a is measured. For such measurement, a touch probe 34a attached to the tool holding device 33a can be used. An automatic tool changer 45 is used to change measuring instruments such as the cutting tool and the touch probe 34a attached to the tool holding device 33a.

[0025] Incidentally, up to this point, the columnar material W' has been machined while being fixed to the first workpiece spindle 12. In other words, the turning and gear cutting processes have been performed while the columnar material W' is rotated around the rotary processing axis C of the first workpiece spindle 12. Therefore, the central axis A of the gear cutting portion 51 and the shaft portion 53 which have been machined coincides with the rotary processing axis C. In other words, up to this point, the columnar material W' has been machined while being rotated around the central axis A.

[0026] The processing up to this point may be performed by having the second work spindle 22 hold the columnar material W'. In this case as well, the vicinity of the end of the shaft-like portion 52 is held, and the shaft-like portion 53 is turned while rotating the columnar material W' around the central axis A (rotation processing axis C'), and the gear cutting circumferential portion 51' is cut to obtain the gear cutting portion 51. In the next step, the shaft-like portion 53 is held by the first work spindle. At this time, it is also possible to transfer the workpiece W obtained by processing the columnar material W' from the second work spindle 22 to the first work spindle 12 automatically by the operation of the processing device 1 alone, without the manual operation of an operator.

[0027] 5A, the workpiece W obtained by forming the gear cutting portion 51 on the columnar material W' is temporarily removed from the first workpiece spindle 12 or transferred from the second workpiece spindle, and one end side of the workpiece W, i.e., the shaft-shaped portion 53 that has been turned, is held by the first workpiece spindle 12, and the workpiece W is attached to the workpiece spindle 12 so that the axis A' (see FIG. 2) is aligned with the rotary machining axis C (S4). At this time, the central axis A of the gear cutting portion 51 of the workpiece W may become eccentric from the rotary machining axis C of the first workpiece spindle 12. Such eccentricity occurs when the first workpiece spindle 12 changes the grip of the workpiece W or when the workpiece W is transferred from the second workpiece spindle 22.

[0028] 5B, in this embodiment, the shape and the like of the gear cutting portion 51 are measured with the rotary machining axis C as a reference (S5). For example, the phase and pitch of the teeth 51a of the gear cutting portion 51 are measured with the rotary machining axis C as a reference. For such measurements, a touch probe 34a attached to the tool holding device 33a can be used as a measuring device. Since the rotary machining axis C is used as a reference, it is preferable to measure the phase and pitch while rotating the workpiece W around the rotary machining axis C.

[0029] Here, the measurement data of the phase and pitch are sent from the control device 40 of the processing device 1 to the calculation device 41. Then, the calculation unit 43 calculates the deviation of the central axis A of the gear cutting portion 51 with respect to the rotary processing axis C of the first work spindle 12. In other words, the amount of eccentricity of the central axis A with respect to the rotary processing axis C and the rotational phase difference (eccentric direction) can be calculated as the deviation.

[0030] The calculation device 41 then determines whether or not there is eccentricity (S6). Here, if the calculated amount of eccentricity of the central axis A, i.e., the amount of eccentricity of the central axis A relative to the rotary machining axis C of the first work spindle 12, is within a predetermined range, it is determined that there is no eccentricity (S6; No). Then, regarding the turning and drilling of the shaft-shaped portion 52, machining is performed as usual, such as by turning around the rotary machining axis C of the first work spindle 12 (S8).

[0031] On the other hand, when the amount of eccentricity exceeds the predetermined range, it is determined that eccentricity exists (S6; Yes). Then, based on the obtained amount and direction of eccentricity, that is, based on the calculated deviation, eccentric machining is performed on the shaft-shaped portion 52 from the other end side of the workpiece W with respect to the rotary machining axis C (S7). In eccentric machining, a tool holding device 33a that holds a cutting tool such as a turning tool 34b is used as a cutting device.

[0032] For example, as shown in FIG. 5C, while rotating the workpiece W around the rotary machining axis C of the first workpiece spindle 12, the turning tool 34b is moved in the radial direction (X-axis direction) in synchronization with the rotation of the workpiece W so as to use the central axis A of the gear cutting portion 51 as a reference, and the outer circumferential surface of the shaft-shaped portion 52 is eccentrically machined. That is, eccentric machining is performed with respect to the rotary machining axis C based on the amount and direction of eccentricity of the central axis A with respect to the rotary machining axis C. Also, for example, the end of the shaft-shaped portion 52 is drilled with the central axis A as a reference to form a hole portion 52a. In such a drilling process, for example, a pilot hole is formed by cutting with a rotary tool 34c such as a U drill held by the tool holding device 33a, and then the hole is expanded with a rotary tool 34c such as an end mill, or the inner diameter is turned with a turning tool. In the hole expanding process using the rotating rotary tool 34c and the turning process using the turning tool, eccentric machining is similarly performed with respect to the rotary machining axis C so that cutting is performed around the central axis A.

[0033] With a gear component obtained in this manner, the shaft-shaped portion 52 on the other end side of the workpiece W can be precisely machined based on the central axis A of the gear cutting portion 51. In other words, machining based on the central axis A of the gear cutting portion can correct deviations in the central axis due to reasons such as changing the grip of the workpiece or other machining defects. The deviations in the central axis due to changing the grip of the workpiece occur because the workpiece is gripped by a new workpiece spindle after the gear cutting portion is formed. In other words, deviations in the central axis can occur in the same way when the workpiece is gripped by the same workpiece spindle, when it is handed over by a different workpiece spindle, or when a workpiece that has been gear-cut by a different machining device is gripped. These deviations can be corrected by the above-mentioned method.

[0034] In the above example, a workpiece W having a gear cutting portion 51 machined on the outer periphery of a stepped columnar shape is machined to machine an axial portion 52 adjacent to the gear cutting portion 51 in the direction of the axis A', but the shape of the workpiece and the machining location are not limited to this.

[0035] For example, if the gear is a columnar part that is cut on a part of the circumference along the axis A', the gear formed by the gear cutting part may be an internal gear or a bevel gear. Here, for the sake of convenience, even if the shape of the workpiece is a part that is short in the direction along the central axis of the gear cutting part or a part that has a hole inside the gear cutting part, it is considered to be a columnar part extending along the axis A'. In addition, the machining part is the same regardless of the shape of the gear product as long as it is a part that is cut by gripping one end side of the workpiece W in the direction along the axis A' and approaching a cutting tool from the other end side after the gear cutting part of the workpiece W is cut around the rotary machining axis C (as a result, the central axis A). For example, the outer periphery or inner periphery of a part adjacent to or separated from the gear cutting part in the axis A' direction, the inner periphery of the gear cutting part, etc. are such machining parts. In addition, regarding the part to be machined after the gear cutting process, the part whose central axis should be aligned with the central axis of the gear cutting part, that is, the part that requires eccentric machining, differs depending on the application of the product. Therefore, among the portions to be machined after gear cutting, there may be included portions that are machined by turning as usual around a rotating machining axis, regardless of the presence or absence of eccentricity.

[0036] The above-mentioned processing method is particularly suitable for use with gear parts that require the workpiece to be changed over or handed over after gear cutting, such as when drilling a bottomed hole from both axial sides in the center of a substantially disk-shaped gear. In addition, when the gear cutting is performed by milling, it is more difficult to align the center axis of the gear cutting portion with the rotation processing axis than when cutting with a hob cutter, so the above-mentioned processing method is also suitable in such cases. Note that if the gear part is one in which the gears are cut on the outer periphery of the workpiece, pitch measurement is easy regardless of the shape, and the above-mentioned processing method can be suitably used.

[0037] The same is true for a gear part in which a shaft hole is formed after gear cutting, as shown in FIG. 6A. Here, the outer periphery of the workpiece W1 having a substantially circular plate shape is the gear cutting portion 61. The gear cutting portion 61 is formed by gear cutting around the central axis A. After the gear cutting, the workpiece W1 is held by a processing device that performs a hole drilling process. Then, the coordinates of the gear cutting portion 61 are measured around the rotary processing axis C of the processing device. Then, the deviation of the central axis A of the gear cutting portion 61 from the rotary processing axis C is calculated. Here, the deviation is calculated as, for example, an eccentricity amount L and a rotation phase difference α. Then, in order to form a shaft hole, a pilot hole 63 is machined, for example, based on the rotary processing axis C. At this time, the rotary processing axis C, which is the center of the pilot hole 63, is deviated from the central axis A by the eccentricity amount L.

[0038] 6B, the hole expanding process is performed eccentrically so that the center of the shaft hole 64 coincides with the central axis A while rotating the workpiece W1 around the rotary machining axis C of the processing device. This also makes it possible to perform processing that accurately forms the shaft hole 64 with the central axis A of the gear cutting portion 61 as a reference by performing eccentric processing with respect to the rotary machining axis C so as to correct the deviation.

[0039] In addition, when measuring the gear cutting portion, the measurement points are the intersections of the pitch circle and the surface of the tooth portion, and measurement values ​​can be obtained only at intermittent points. As a result, the measurement points do not coincide with the eccentricity direction, and an error occurs between the rotational phase difference calculated from the measurement points and the actual rotational phase difference. This error is likely to be large especially when the number of teeth is small. In addition, when measuring the gear cutting portion, it is preferable to perform pitch measurement in this way to calculate the amount of eccentricity, etc., since this increases the concentricity between the gear cutting portion and other parts. In addition, errors due to hob cutter eccentricity do not affect the outer circumference circle (tooth tip), and therefore cannot be detected without pitch measurement.

[0040] As described above, when the rotational phase difference calculated from the measurement points has an error, for example, a method can be used in which a least squares circle is calculated from a graph plot of the relationship between the pitch error and phase at each measurement point obtained from the measurement value, and a cosine curve that fits this can be obtained. By determining the apex of the obtained cosine curve as the rotational phase difference, it is possible to obtain an accurate eccentricity direction and amount. The eccentricity direction and amount may be determined by other known methods. In addition, the presence or absence of eccentricity can be automatically determined using such a graph of the relationship between the pitch error and the phase. For example, a correlation value with the cosine curve of the graph is calculated, and the presence or absence of eccentricity is determined based on this value.

[0041] Although the representative embodiment of the present invention and the associated modifications have been described above, the present invention is not necessarily limited thereto and may be modified as appropriate by those skilled in the art. In other words, those skilled in the art will be able to find various alternative embodiments and modifications without departing from the scope of the appended claims. [Explanation of symbols]

[0042] 1 Processing equipment 12 First work spindle 22 Second work spindle 30 Mobile Device 33a Tool holding device 34a Touch probe (measuring instrument) 34b Turning tools 34c Rotary tools 40 Control device 41 Arithmetic device 45 Automatic tool changer 51 Gear cutting section 51a Teeth 52, 53 Shaft-shaped part A center axis C Rotating axis W work W' Columnar Material

Claims

1. A method for machining a gear part, comprising: gripping the workpiece on a workpiece spindle at one end of the workpiece, which has a gear-cut portion that is gear-cut on a part of the axial direction of the columnar workpiece and on the circumference around it, so that the axial direction is aligned with the rotational machining axis; measuring the gear-cut portion to calculate the deviation of the central axis of the gear-cut portion from the rotational machining axis; and performing eccentric machining of the shaft-shaped portion of the workpiece that has not been gear-cut relative to the rotational machining axis from the other end of the workpiece based on the deviation.

2. The method for machining gear parts according to Claim 1, wherein the eccentric machining is a turning operation on the workpiece.

3. The method for machining a gear part according to claim 1, wherein the measurement of the gear cutting portion is performed by measuring the pitch of the teeth of the gear cutting portion while rotating the workpiece around the rotary machining axis.

4. The method for machining gear parts according to Claim 3, wherein the displacement consisting of the eccentricity and eccentricity direction of the central axis with respect to the rotating machining axis is calculated.

5. A method for machining gear parts according to any one of claims 1 to 4, wherein the eccentric machining is performed while the workpiece is rotated around the rotating machining axis.

6. A method for machining gear parts according to any one of claims 1 to 4, wherein the eccentric machining is performed using a rotating rotary tool.

7. The gear cutting portion is gear-cut on the outer circumference of the workpiece, a method for machining a gear part according to any one of claims 1 to 4.

8. A method for machining a gear part according to any one of claims 1 to 4, comprising: gripping the columnar material on the workpiece spindle in order to machine the columnar material into the workpiece; turning the one end of the columnar material that is the workpiece; and cutting the gear portion.

9. A geared portion is formed on a part of the columnar workpiece along its axial direction and on the circumference around it, and the workpiece is gripped on the workpiece spindle at one end of the workpiece so that the axial direction is aligned with the rotational machining axis, and the geared portion is measured. From the measured values, the deviation of the central axis of the gear cutting portion from the rotational machining axis is calculated. A gear component machining program that causes eccentric machining of the axial portion of the workpiece that has not been gear-cut relative to the rotating machining axis, from the other end of the workpiece, based on the calculated displacement.

10. The machining program for a gear component according to claim 9, wherein the eccentric machining is a turning operation on the workpiece.

11. The gear cutting program according to claim 9, wherein the measurement of the gear cutting portion is performed by rotating the workpiece around the rotary machining axis while measuring the pitch of the teeth of the gear cutting portion.

12. A gear part machining program according to claim 11, which calculates the displacement consisting of the eccentricity and eccentricity direction of the central axis with respect to the rotating machining axis.

13. A gear component machining program according to any one of claims 9 to 12, comprising: gripping the columnar material onto the workpiece spindle; turning the one end of the columnar material that is the workpiece; and cutting the gear portion of the columnar material.

14. A first workpiece spindle that rotatably grips a columnar workpiece, A tool holder for holding measuring instruments or tools, A moving device that allows the first workpiece spindle and the tool holder to move relative to each other, The control device includes the first workpiece spindle, the tool holder, and the moving device, According to the machining program, the workpiece has a gear-cut portion that is machined on a part of the axial direction of the workpiece and on the circumference around it, and the workpiece is held on the first workpiece spindle with the axial direction aligned with the rotational machining axis, and the gear-cut portion is measured by the measuring instrument held in the tool holding device. From the measured values, the deviation of the central axis of the gear cutting portion from the rotational machining axis is calculated. A machining apparatus that, based on the calculated displacement, uses the tool held in the tool holding device to perform eccentric machining of the axial portion of the workpiece that has not been gear-cut relative to the rotating machining axis, from the other end of the workpiece.

15. The machining apparatus according to claim 14, wherein the eccentric machining is a turning operation on the workpiece.

16. Further including a second workpiece spindle for rotatably gripping the workpiece, The processing apparatus according to claim 14, wherein, in order to process a columnar material into the workpiece, the columnar material is gripped by the second workpiece spindle, the end of the columnar material that is the workpiece is turned, and the gear cutting portion is gear cut.

17. The processing apparatus according to any one of claims 14 to 16, further comprising a replacement device for making the tool and the measuring instrument held in the tool holding device replaceable.

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