Gear machining method and gear machining apparatus

Abstract

To provide a gear machining method and a gear machining device that are able to obtain a desired involute tooth surface when performing polish machining or grind machining on an involute tooth surface by means of a cycloid locus of a grinding wheel relative to a workpiece.SOLUTION: A workpiece W and a rotary tool T are synchronously rotated, and polish machining or grind machining on an involute tooth surface Wb of the gear-shaped workpiece W is performed by means of a cycloid locus of a grinding wheel Tb of the rotary tool T relative to the workpiece W. During this machining, the rotary tool T is moved relative to the workpiece W in a direction perpendicular to a rotational axis Ct of the rotary tool T.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a gear processing method and a gear processing apparatus by polishing or grinding.

Background Art

[0002] Patent Document 1 describes performing gear grinding with a spiral grinding wheel. It is also known to perform gear honing with a spiral grinding wheel. Patent Document 2 describes performing gear processing with a skiving cutter.

[0003] Patent Document 3 describes a processing method in which, by using a rotary tool provided with one or more grinding wheels protruding radially outward and synchronously rotating a workpiece and the rotary tool in a state where the rotation axis of the workpiece and the rotation axis of the rotary tool are arranged in parallel, the movement locus of the grinding wheel with respect to the workpiece is made into a cycloid locus, and the involute tooth surface of the workpiece is ground by the cycloid locus of the grinding wheel with respect to the workpiece.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] When performing polishing or grinding of an involute tooth surface by the processing method described in Patent Document 3, it has been found that due to the deviation between the cycloid locus of the grinding wheel with respect to the workpiece and the involute shape of the involute tooth surface, the polishing or grinding is insufficient, and a shape error occurs in the involute tooth surface.

[0006] The present invention has been made in view of the above problems, and aims to provide a gear machining method and gear machining apparatus that can obtain a desired involute tooth surface when polishing or grinding an involute tooth surface by the cycloidal trajectory of a grinding wheel on a workpiece. [Means for solving the problem]

[0007] One aspect of the present invention is, A gear machining method for polishing or grinding the involute tooth surface of a gear-shaped workpiece, A machining method is provided in which a rotary tool equipped with one or more grinding wheels protruding radially outward is used, and the workpiece and the rotary tool are rotated synchronously with the rotation axis of the workpiece and the rotation axis of the rotary tool positioned parallel to each other, thereby making the trajectory of the grinding wheels relative to the workpiece a cycloidal trajectory, and polishing or grinding of the involute tooth surface is performed by the cycloidal trajectory of the grinding wheels relative to the workpiece. The gear machining method involves moving the rotary tool relative to the workpiece in a direction perpendicular to the rotation axis of the rotary tool during the polishing or grinding process.

[0008] Other aspects of the present invention include: A gear machining apparatus for polishing or grinding the involute tooth surface of a gear-shaped workpiece, A rotary tool equipped with one or more grinding wheels protruding radially outward, A control device for controlling the operation of the workpiece and the rotary tool, Equipped with, The control device is The system is configured such that the rotation axis of the workpiece and the rotation axis of the rotary tool are positioned parallel to each other, and the workpiece and the rotary tool are rotated synchronously, thereby creating a cycloidal trajectory for the grinding wheel relative to the workpiece, and the polishing or grinding of the involute tooth surface is performed by following the cycloidal trajectory of the grinding wheel relative to the workpiece. Furthermore, the gear machining apparatus is configured such that, during the polishing or grinding process, the rotary tool is moved relative to the workpiece in a direction perpendicular to the rotation axis of the rotary tool. [Effects of the Invention]

[0009] In the gear machining method according to one embodiment described above, the cycloidal trajectory of the grinding wheel relative to the workpiece is corrected so as to approach the involute shape of the involute tooth surface. Specifically, when polishing or grinding the involute tooth surface on the workpiece with the grinding wheel of a rotary tool, the rotary tool is moved relative to the workpiece in a direction perpendicular to the rotation axis of the rotary tool. This corrects the discrepancy between the involute shape of the involute tooth surface and the cycloidal trajectory of the grinding wheel relative to the workpiece to a small extent.

[0010] Therefore, according to the gear machining method of the above embodiment, when polishing or grinding an involute tooth surface by the cycloidal trajectory of the grinding wheel on the workpiece, a desired involute tooth surface can be obtained.

[0011] In the gear machining apparatus of the other embodiment described above, similar to the gear machining method of the one embodiment described above, the cycloidal trajectory of the grinding wheel with respect to the workpiece is corrected so as to approach the involute shape of the involute tooth surface.

[0012] Therefore, according to the gear processing apparatus of the other embodiment described above, when polishing or grinding an involute tooth surface by the cycloidal trajectory of the grinding wheel on the workpiece, a desired involute tooth surface can be obtained. [Brief explanation of the drawing]

[0013] [Figure 1] This is a diagram showing a gear processing device. [Figure 2] This is a diagram showing the electrical configuration of the control device of the gear processing device. [Figure 3] This is a diagram showing a workpiece and a rotary tool. [Figure 4] This is a diagram showing the relative movement locus of the grinding wheel of the rotary tool with respect to the workpiece. [Figure 5] This is a diagram showing the relative movement locus of the cutting edge of the grinding wheel of the rotary tool with respect to the workpiece. [Figure 6] This is a graph showing the amount of deviation in the position of the operating locus of the cutting edge of the grinding wheel with respect to the involute shape of the involute tooth surface when the diameter from the rotation center of the rotary tool to the cutting edge of the grinding wheel is appropriately changed. [Figure 7] This is a graph showing the change in the correction amount in the X-axis direction when using the time change of the amplitude in the range including the extreme value of the cosine wave. [Figure 8] This is a graph showing the geometric deviation amount (deviation amount before correction) between the involute shape of the involute tooth surface and the operating locus of the cutting edge of the grinding wheel, and the correction amount in the X-axis direction of the rotary tool with respect to the workpiece in the first example. [Figure 9] This is a graph showing the deviation amount before correction in the first example, and the deviation amount after correction after correcting the relative position in the X-axis direction of the rotary tool with respect to the workpiece according to the time change of the amplitude in the range including the extreme value of the cosine wave. [Figure 10] This is a graph showing the geometric deviation amount (deviation amount before correction) between the involute shape of the involute tooth surface and the operating locus of the cutting edge of the grinding wheel, and the correction amount in the X-axis direction of the rotary tool with respect to the workpiece in the second example. [Figure 11] This is a graph showing the deviation amount before correction in the second example, and the deviation amount after correction after correcting the relative position in the X-axis direction of the rotary tool with respect to the workpiece so as to make the geometric deviation amount zero. [Figure 12]A graph showing the machining resistance before correction as a result of measuring the machining resistance in the normal direction of the involute tooth surface during machining measurement in the third example, and the machining resistance after correction when the rotary tool is relatively moved in the X-axis direction with respect to the workpiece so that the machining resistance in the normal direction of the involute tooth surface during machining becomes constant. [Figure 13] A flowchart showing a gear machining method in the fourth example.

Mode for Carrying Out the Invention

[0014] (Embodiment) 1. Configuration of Gear Machining Apparatus 1 The gear machining apparatus 1 is an apparatus for executing a gear machining method. The gear machining apparatus 1 performs polishing or grinding of an involute tooth surface Wb on a gear-shaped workpiece W using a rotary tool T. The gear machining apparatus 1 is composed of a plurality of structures for relatively moving the rotary tool T and the workpiece W. For the gear machining apparatus 1, for example, the configuration of a known machining center is applied.

[0015] A configuration example of the gear machining apparatus 1 will be described with reference to FIG. 1. The gear machining apparatus 1 applies a machining center capable of tool change. In addition to polishing or grinding the involute tooth surface Wb, the gear machining apparatus 1 can also perform cutting of the tooth profile on the workpiece W by gear skiving, hobbing, or the like. Note that the gear machining apparatus 1 may be a dedicated machine for polishing or grinding.

[0016] In this embodiment, the gear machining apparatus 1 exemplifies a case where the configuration of a horizontal machining center is applied as shown in FIG. 1, but other configurations such as a vertical machining center can also be applied. As shown in FIG. 1, the gear machining apparatus 1 has, for example, three linear drive axes (X-axis, Y-axis, Z-axis) that are orthogonal to each other. Here, the direction parallel to the rotation axis line Ct of the rotary tool T is defined as the Z-axis direction, and the two axes orthogonal to the Z-axis direction are defined as the X-axis and the Y-axis. In FIG. 1, the horizontal direction is the X-axis direction, and the vertical direction is the Y-axis direction.

[0017] Furthermore, the gear machining apparatus 1 has one rotary drive axis (rotary drive axis around the B axis) for changing the relative orientation of the workpiece W and the rotary tool T. In this embodiment, the B axis is a rotary drive axis for changing the orientation of the workpiece W around an axis parallel to the Y axis. The gear machining apparatus 1 also has a rotary drive axis for rotating the rotary tool T (rotary drive axis around the Ct axis) and a rotary drive axis for rotating the workpiece W (rotary drive axis around the Cw axis). In this embodiment, the rotation axis Ct of the rotary tool T is always parallel to the Z axis. The rotation axis Cw of the workpiece W is a horizontal axis and can take angles with respect to the Z axis and X axis depending on the B axis angle. However, in polishing or grinding operations, the rotation axis Cw of the workpiece W is parallel to the rotation axis Ct of the rotary tool T.

[0018] In the gear machining apparatus 1, the configuration for relative movement between the workpiece W and the rotary tool T can be selected as appropriate. For example, the gear machining apparatus 1 may have an A axis, which is a rotation axis parallel to the X axis, instead of a B axis. In the following, we will take as an example the case in which the rotary tool T can move linearly in the Y axis and Z axis directions, the workpiece W can move linearly in the X axis direction, and the workpiece W can rotate around the B axis.

[0019] The gear machining apparatus 1 comprises a bed 10, a workpiece holder 20, a tool holder 30, and a control device 40. The bed 10 is installed on a mounting surface and is formed in a shape corresponding to the shape of the workpiece holder 20 and the tool holder 30. In this embodiment, the bed 10 is, for example, rectangular. A pair of X-axis guide rails for moving the workpiece holder 20 in the X-axis direction and a pair of Z-axis guide rails for moving the tool holder 30 in the Z-axis direction are formed on the upper surface of the bed 10.

[0020] The workpiece holder 20 allows the workpiece W to move in the X-axis direction, rotate around the B-axis, and rotate around the Cw-axis relative to the bed 10. The workpiece holder 20 mainly comprises an X-axis moving table 21, a B-axis rotating table 22, and a workpiece spindle device 23. The X-axis moving table 21 is driven by an X-axis motor 211, which is a linear motor or a ball screw mechanism, and moves in the X-axis direction while being guided by a pair of X-axis guide rails.

[0021] The B-axis rotating table 22 is mounted on the upper surface of the X-axis moving table 21 and moves integrally with the X-axis moving table 21 in the direction of the X-axis. The B-axis rotating table 22 is also mounted so as to be rotatable around the B-axis relative to the X-axis moving table 21. The B-axis rotating table 22 is equipped with a rotary motor and a rotation angle detector (not shown), and the B-axis rotating table 22 can rotate around the B-axis by driving the rotary motor.

[0022] The workpiece spindle device 23 is mounted on the B-axis rotating table 22 and rotates integrally with the B-axis rotating table 22 around the B-axis. The workpiece spindle device 23 rotatably holds the workpiece W. The workpiece spindle device 23 comprises a workpiece spindle base 23a, a workpiece spindle housing 23b, and a workpiece spindle 23c. The workpiece spindle base 23a is fixed to the upper surface of the B-axis rotating table 22.

[0023] The workpiece spindle housing 23b is fixed to the workpiece spindle base 23a and has a cylindrical inner surface centered on the Cw axis centerline which is perpendicular to the B axis centerline. The workpiece spindle 23c is rotatably supported by the workpiece spindle housing 23b. The workpiece W is detachably held by the workpiece spindle 23c. In other words, the workpiece spindle 23c rotatably holds the workpiece W in the workpiece spindle housing 23b around the Cw axis and rotates integrally with the workpiece W.

[0024] The workpiece spindle housing 23b is equipped with a rotary motor and a rotation angle detector (not shown), and the workpiece spindle device 23 is capable of rotating the workpiece W around the Cw axis by the drive of the rotary motor. In this way, the workpiece holding device 20 is capable of moving the workpiece W in the X-axis direction relative to the bed 10, rotating around the B axis, and rotating around the Cw axis.

[0025] The tool holder 30 mainly comprises a column 31, a saddle 32, and a tool spindle device 33. The column 31 is driven by a drive device such as a linear motor or a ball screw mechanism (not shown) and moves in the Z-axis direction while being guided by the Z-axis guide rail of the bed 10. A Y-axis guide rail is formed on the vertically extending side surface of the column 31. The saddle 32 is driven by a Y-axis motor 321, which is part of a linear motor or a ball screw mechanism, and moves in the Y-axis direction while being guided by the Y-axis guide rail of the column 31.

[0026] The tool spindle device 33 is mounted on the saddle 32 and moves integrally with the saddle 32 in the Y-axis direction. The tool spindle device 33 holds the rotary tool T. The tool spindle device 33 is equipped with a rotary motor and a rotation angle detector (not shown), and the tool spindle device 33 makes the rotary tool T rotatable around the Ct axis by the drive of the rotary motor. In this way, the tool holding device 30 holds the rotary tool T so that it can move in the Y-axis direction and the Z-axis direction relative to the bed 10, and can rotate around the Ct axis.

[0027] The tool spindle device 33 comprises a tool spindle housing 33a and a tool spindle 33b. The tool spindle housing 33a is fixed to the saddle 32, and the tool spindle 33b of the tool spindle device 33 is rotatably supported by the tool spindle housing 33a. A rotary tool T is detachably held on the tool spindle 33b. In other words, the tool spindle 33b rotatably holds the rotary tool T in the tool spindle housing 33a around the Ct axis and rotates integrally with the rotary tool T.

[0028] The control device 40 controls the drive devices that constitute the workpiece holder 20 and the tool holder 30. The control device 40 controls the operation, enabling the rotation of the workpiece W, the rotation of the rotary tool T, and the relative movement of the workpiece W and the rotary tool T in the X-axis, Y-axis, and Z-axis directions. When performing polishing or grinding by synchronously rotating the workpiece W and the rotary tool T, the control device 40 is configured to move the rotary tool T relative to the workpiece W in the X-axis direction, which is perpendicular to the rotation axis Ct of the rotary tool T. In this embodiment, the operation of the X-axis moving table 21 causes the workpiece W to move in the X-axis direction relative to the rotary tool T.

[0029] The configuration of the control device 40 will be described with reference to Figure 2. The control device 40 includes a synchronous rotation control unit 401 that controls the synchronous rotation of the workpiece W and the rotary tool T, and an axis movement control unit 402 that controls the relative movement of the rotary tool T with respect to the workpiece W in the X-axis direction. The control device 40 stores synchronous rotation data D1 for synchronizing the workpiece W and the rotary tool T, and axis movement data D2 for controlling the relative movement of the rotary tool T with respect to the workpiece W in the X-axis direction. When polishing or grinding of an involute tooth surface Wb is performed, the synchronous rotation data D1 is sent to the synchronous rotation control unit 401, and the axis movement data D2 is sent to the axis movement control unit 402.

[0030] The synchronous rotation control unit 401 controls the synchronous rotation of the workpiece W and the rotary tool T by operating the workpiece spindle unit 23 and the tool spindle unit 33 using the synchronous rotation data D1. The axis movement control unit 402 controls the relative movement of the rotary tool T in the X-axis direction relative to the workpiece W by controlling the X-axis motor 211 using the axis movement data D2. Alternatively, the axis movement control unit 402 may control the relative movement of the rotary tool T in the X-axis and Y-axis directions relative to the workpiece W by controlling the X-axis motor 211 and the Y-axis motor 321 using the axis movement data D2.

[0031] 2. Workpiece W The workpiece W will be explained with reference to Figure 3. The workpiece W to be machined is a gear-shaped (external gear or internal gear) with convex teeth Wc formed on its outer or inner circumferential surface. In other words, the workpiece W to be machined has convex teeth Wc formed on it beforehand. Here, in the workpiece W to be machined, each convex tooth Wc has an involute tooth surface Wb on both sides in the circumferential direction E. The workpiece W has a tooth groove Wa between adjacent convex teeth Wc in the circumferential direction E, that is, between the involute tooth surfaces Wb facing each other in the circumferential direction E.

[0032] This embodiment shows an example of polishing or grinding an internal gear-shaped workpiece W. In this case, the rotary tool T is positioned on the inner circumference side of the workpiece W. The internal gear-shaped workpiece W in this embodiment is a spur gear whose tooth trace direction is parallel to the rotation axis Cw of the workpiece W. The internal or external gear-shaped workpiece W may also be a helical gear whose tooth trace direction is at an angle to the rotation axis Cw of the workpiece W. When polishing or grinding an external gear-shaped workpiece W, the rotary tool T is positioned on the outer circumference side of the workpiece W.

[0033] 3.Rotary tool T The configuration of the rotary tool T will be explained with reference to Figure 3. The rotary tool T is a tool used for polishing or grinding the involute tooth surface Wb. Polishing is a process that smooths out the irregularities of the pre-formed involute tooth surface Wb. Grinding is a process that removes a small amount of material from the pre-formed involute tooth surface Wb.

[0034] The rotary tool T comprises a tool body Ta and a grinding wheel Tb. The tool body Ta is formed, for example, in a cylindrical shape and is held on the tool spindle 33b such that its central axis coincides with the Ct axis centerline of the tool spindle 33b. The tool body Ta is formed from, for example, steel.

[0035] The grinding wheel Tb is provided at the axial end of the tool body Ta and is positioned to protrude radially outward from the tool body Ta. In other words, when viewed from the axial direction of the tool body Ta, the grinding wheel Tb is formed as a rectangle extending radially, or as a trapezoid that narrows towards the tip. In this embodiment, the grinding wheel Tb is formed as a plate extending in the axial direction of the tool body Ta so as to be parallel to the rotation axis Ct of the tool body Ta. Furthermore, when viewed from the direction normal to the surface of the plate (right in Figure 3), the grinding wheel Tb is formed as a rectangle, or as a trapezoid that narrows towards the tip.

[0036] In this embodiment, the case is assumed to be when the tooth trace direction of the convex teeth Wc of the workpiece W is parallel to the rotation axis Cw of the workpiece W, and the grinding wheel Tb is formed in a plate shape that extends in the axial direction of the tool body Ta so as to be parallel to the rotation axis Ct of the tool body Ta. However, if the case is assumed to be when the tooth trace direction of the convex teeth Wc of the workpiece W is at an angle with respect to the rotation axis Cw of the workpiece W, the grinding wheel Tb may also be formed to be at an angle with respect to the rotation axis Ct of the tool body Ta.

[0037] Therefore, the grinding wheel Tb comprises a tip surface Tb1 facing radially outward from the rotating tool T and a side surface Tb2 facing circumferentially from the rotating tool T. The portion of the grinding wheel Tb that performs polishing or grinding of the involute tooth surface Wb of the workpiece W is the ridge portion between the tip surface Tb1 and the side surface Tb2, and this ridge portion Tb3 constitutes the cutting edge Tb3 of the grinding wheel Tb.

[0038] The gear machining apparatus 1 performs polishing or grinding of the involute tooth surface Wb of the workpiece W by synchronously rotating the workpiece W and the rotary tool T with the rotation axis Cw of the workpiece W and the rotation axis Ct of the rotary tool T in parallel. Synchronous rotation means rotating the workpiece W and the rotary tool T with the initial position in the circumferential direction E of each convex tooth Wc of the workpiece W and the initial position in the rotation direction of the grinding wheel Tb on the rotary tool T set. In this embodiment, the workpiece W and the rotary tool T rotate at a constant speed with an appropriate rotation speed ratio set.

[0039] Furthermore, the grinding wheel Tb may have rigidity that is hardly elastically deformable, or it may have rigidity that allows for elastic deformation. When performing polishing, a grinding wheel Tb that is easily elastically deformable can be used, and when performing grinding, a grinding wheel Tb that is not easily elastically deformable can be used.

[0040] In this embodiment, the rotary tool T is given as an example configuration with one grinding wheel Tb, but it may also be equipped with multiple grinding wheels Tb. The multiple grinding wheels Tb may be provided intermittently on the outer circumferential surface of the tool body Ta in the direction of rotation of the rotary tool T.

[0041] 4. Gear machining operation The method for machining the involute tooth surface Wb of a workpiece W using a rotary tool T will be explained with reference to Figures 4 and 5. As shown in Figure 3, the rotation axis Cw of the workpiece W and the rotation axis Ct of the rotary tool T are positioned parallel to each other. In this state, the workpiece W and the rotary tool T are rotated synchronously. In Figure 3, the workpiece W and the rotary tool T are rotated clockwise. Due to this relative motion between the workpiece W and the rotary tool T, the trajectory of the grinding wheel Tb of the rotary tool T relative to the workpiece W is a cycloidal trajectory. Polishing or grinding of the involute tooth surface Wb is performed by the cycloidal trajectory of the grinding wheel Tb relative to the workpiece W.

[0042] Figure 4 shows a magnified view of the area where the grinding wheel Tb contacts the involute tooth surface Wb of the workpiece W. In Figure 4, assuming that the workpiece W and the rotary tool T rotate clockwise and the workpiece W is fixed, the movement trajectories Tr1 and Tr2 of the cutting edge Tb3 of the grinding wheel Tb of the rotary tool T moving within the tooth groove Wa are schematically shown. The movement trajectory Tr1 of the cutting edge Tb3 of the grinding wheel Tb entering the tooth groove Wa is shown by a dashed line, and the movement trajectory Tr2 of the cutting edge Tb3 advancing out of the tooth groove Wa is shown by a solid line.

[0043] With the rotation axis Cw of the workpiece W and the rotation axis Ct of the rotary tool T positioned parallel to each other, the workpiece W and the rotary tool T are rotated synchronously, causing the cutting edge Tb3 of the grinding wheel Tb of the rotary tool T to move in a cycloidal trajectory relative to the workpiece W. When the grinding wheel Tb enters the tooth groove Wa by the motion trajectory Tr1, the cutting edge Tb3 does not machine the involute tooth surface Wb located on the other side of the circumferential direction E of the workpiece W. When the grinding wheel Tb advances out of the tooth groove Wa by the motion trajectory Tr2, the cutting edge Tb3 machines the involute tooth surface Wb located on one side of the circumferential direction E of the workpiece W from the tooth root position Wb1 to the tooth tip position Wb3. Note that the tooth root position Wb1 does not necessarily have to be the deepest position of the tooth groove Wa, but refers to the position on the tooth root side where machining of the involute tooth surface Wb is required.

[0044] The cycloidal trajectory of the grinding wheel Tb as it advances from within the tooth groove Wa, Tr2, does not perfectly coincide with the involute shape Wr of the involute tooth surface Wb located on one side in the circumferential direction E. At the tooth root position Wb1 and tooth tip position Wb3 of the involute tooth surface Wb, the trajectory Tr2 shifts away from the involute tooth surface Wb, and at the intermediate position Wb2 of the involute tooth surface Wb, it shifts towards the involute tooth surface Wb. In this embodiment, the trajectory Tr2 of the cutting edge Tb3 of the grinding wheel Tb relative to the involute tooth surface Wb is adjusted so that the amount of displacement at the intermediate position Wb2 of the involute tooth surface Wb becomes zero.

[0045] Figure 5 shows a magnified view of the positional misalignment between the involute shape Wr of the involute tooth surface Wb and the cycloidal trajectory Tr2 of the cutting edge Tb3 of the grinding wheel Tb relative to the workpiece W. The cutting edge Tb3 of the grinding wheel Tb is formed by the corner (ridge) between the tip surface Tb1 and the side surface Tb2 of the grinding wheel Tb. When performing polishing or grinding, the diameter from the rotation center of the rotary tool T to the cutting edge Tb3 of the grinding wheel Tb, the rotational speed ratio of the workpiece W and the rotary tool T, and the initial machining phase of the rotary tool T relative to the workpiece W are set so that the involute shape Wr of the involute tooth surface Wb and the cycloidal trajectory of the grinding wheel Tb relative to the workpiece W coincide as much as possible. However, even with these settings, a positional misalignment occurs between the involute shape Wr of the involute tooth surface Wb and the cycloidal trajectory Tr2 of the cutting edge Tb3 of the grinding wheel Tb. The distance from the rotation center of the rotary tool T to the cutting edge Tb3 of the grinding wheel Tb is expressed as a radius, but a diameter (corresponding to the rotational diameter of the cutting edge Tb3) may be used in accordance with the specifications of the control device 40 of the gear machining device 1.

[0046] Figure 6 shows the amount of displacement of the movement trajectory Tr2 of the cutting edge Tb3 of the grinding wheel Tb relative to the involute shape Wr of the involute tooth surface Wb, when polishing or grinding is performed on one side of the involute tooth surface Wb of the workpiece W from the tooth root position Wb1 to the tooth tip position Wb3, with the diameter from the rotation center of the rotary tool T to the cutting edge Tb3 of the grinding wheel Tb being appropriately changed as tool samples 1 to 3. The radius of tool sample 2 is larger than the radius of tool sample 1, and the radius of tool sample 3 is larger than the radius of tool sample 2.

[0047] In Figure 6, the positional displacement is shown as the displacement in the tooth thickness direction. The displacement in the tooth thickness direction corresponds to the displacement in the X-axis direction. In Figure 6, the displacement of the motion trajectory Tr2 away from the involute shape Wr of the involute tooth surface Wb is indicated by a minus sign (-). As shown in Figure 6, in all of tool samples 1 to 3, the displacement in the tooth thickness direction increases as you move from the intermediate position Wb2 of the involute tooth surface Wb to the root position Wb1 or the tip position Wb3. Also, the displacement in the tooth thickness direction is largest for tool sample 1, which has the smallest radius, and the displacement in the tooth thickness direction is smallest for tool sample 3, which has the largest radius.

[0048] Furthermore, after adjusting the diameter from the rotation center of the rotary tool T to the cutting edge Tb3 of the grinding wheel Tb, and the rotational speed ratio between the workpiece W and the rotary tool T, when the workpiece W and the rotary tool T are rotated clockwise, polishing or grinding is sequentially performed on all involute tooth surfaces Wb located on one side of the circumferential direction E by the grinding wheel Tb. Also, when the workpiece W and the rotary tool T are rotated counterclockwise (in the opposite direction), polishing or grinding is sequentially performed on all involute tooth surfaces Wb located on the other side of the circumferential direction E by the grinding wheel Tb.

[0049] 5. Correction of the cycloidal trajectory of the grinding wheel Tb relative to the workpiece W. During polishing or grinding operations using the gear processing apparatus 1 and gear processing method, the rotary tool T is moved relative to the workpiece W in a direction perpendicular to the rotation axis Ct of the rotary tool T in order to correct the positional misalignment of the movement trajectory Tr2 of the cutting edge Tb3 of the grinding wheel Tb with respect to the involute shape Wr of the involute tooth surface Wb. In this embodiment, the rotary tool T is moved relative to the workpiece W in the X-axis direction in order to correct the positional misalignment.

[0050] In Figure 3, the relative movement of the rotary tool T relative to the workpiece W in the X-axis direction is indicated by the symbol Xm. The rotational directions of the workpiece W and the rotary tool T are indicated by arrows. In order to correct for positional misalignment, the rotary tool T may be moved relative to the workpiece W in the Y-axis direction, or it may be moved relative to both the X-axis and Y-axis directions.

[0051] The relative movement of the rotary tool T in the X-axis direction relative to the workpiece W during machining can be based on geometric displacement, machining resistance acting on the grinding wheel Tb, or both geometric displacement and machining resistance acting on the grinding wheel Tb. As shown in Figures 4 and 5, when the displacement of the movement trajectory Tr2 of the cutting edge Tb3 of the grinding wheel Tb relative to the involute shape Wr of the involute tooth surface Wb is large, correction based on geometric displacement is effective.

[0052] 5-1. First Example The first example of correcting misalignment is to move the rotary tool T relative to the workpiece W in the X-axis direction to reduce the geometric deviation of the motion trajectory Tr2 of the grinding wheel Tb with respect to the involute shape Wr of the involute tooth surface Wb. In Figures 4 and 5, x1 shows the geometric deviation of the motion trajectory Tr2 at the tooth root position Wb1 of the involute tooth surface Wb, and x2 shows the geometric deviation of the motion trajectory Tr2 at the tooth tip position Wb3 of the involute tooth surface Wb.

[0053] The relative movement of the rotary tool T in the X-axis direction relative to the workpiece W occurs in synchronization with the rotation of the workpiece W and the rotary tool T during machining. In other words, the starting point of the relative movement of the rotary tool T in the X-axis direction relative to the workpiece W is determined in relation to the initial circumferential position E of each convex tooth Wc of the workpiece W and the initial rotational position of the grinding wheel Tb on the rotary tool T.

[0054] As shown in Figures 4 to 6, the relative movement of the rotary tool T in the X-axis direction to the workpiece W is performed in a reciprocating motion as the grinding wheel Tb contacts the involute tooth surface Wb located on one side of the circumferential direction E of the workpiece W, from the tooth root position Wb1 to the tooth tip position Wb3, depending on the geometric displacement of the tooth root position Wb1 and tooth tip position Wb3, which are shifted away from the involute shape Wr relative to the intermediate position Wb2 of the involute tooth surface Wb. In other words, when the workpiece W and the rotary tool T rotate and the grinding wheel Tb processes the involute tooth surface Wb from the tooth root position Wb1 to the tooth tip position Wb3, the rotary tool T moves from one side to the other in the X-axis direction relative to the workpiece W, and then moves from the other side to the one side in the X-axis direction, in order to minimize the geometric displacement.

[0055] In the first example, the relative movement of the rotary tool T with respect to the workpiece W in the X-axis direction is achieved by utilizing the temporal change in amplitude within a range that includes the extremum of a cosine wave, rather than making the geometric displacement zero in at least a portion of the machining range of the involute tooth surface Wb. The geometric displacement between the involute shape Wr of the involute tooth surface Wb and the motion trajectory Tr2 of the cutting edge Tb3 of the grinding wheel Tb changes curvilinearly, including a state where it becomes zero at the intermediate position Wb2 of the involute tooth surface Wb. This curvilinear change approximates the curvilinear change within a range that includes the extremum of a cosine wave.

[0056] Therefore, the relative movement of the rotary tool T in the X-axis direction relative to the workpiece W can be controlled by utilizing the temporal change in amplitude within the range that includes the extremum of the cosine wave. The temporal change in amplitude of a cosine wave is a continuous, curved change. Thus, by utilizing the temporal change in amplitude of the cosine wave, the relative movement of the rotary tool T in the X-axis direction relative to the workpiece W can be made simple and smooth.

[0057] The involute shape Wr of the involute tooth surface Wb and the motion trajectory Tr2 of the cycloidal trajectory of the cutting edge Tb3 of the grinding wheel Tb relative to the workpiece W are calculated from the geometric positional relationship between the two. Then, the difference between the position of the involute shape Wr in the X-axis direction and the position of the motion trajectory Tr2 in the X-axis direction is calculated. To minimize this difference, the temporal change in amplitude within the range including the extremum of the cosine wave is used. The temporal change in amplitude within the range including the extremum of the cosine wave becomes the correction amount for the relative movement of the rotary tool T in the X-axis direction relative to the workpiece W.

[0058] The amount of correction for the rotational tool T in the X-axis direction relative to the workpiece W, due to the temporal change in the amplitude of the cosine wave within the range containing the extreme value, may be determined based on the following equation. That is, when the amplitude of the cosine wave is A [mm], the rotational phase of the workpiece W is θ [°], the adjustment amount of the rotational phase of the workpiece W is Δθa [°], and the number of teeth of the workpiece W is Zw, the correction amount X [mm] in the X-axis direction can be determined based on X = A × cos(Zw × θ - Δθa) - A. A, Zw, and Δθa are constants, and θ and X are variables.

[0059] Figure 7 shows the change in the correction amount in the X-axis direction when utilizing the temporal change in amplitude within the range including the extremum of a cosine wave. In Figure 7, the range of rotational phase θH [°] used for correction in the X-axis direction during machining is set as an appropriate range including the extremum. Note that a sine wave may be used instead of a cosine wave. In this case, the correction amount X in the X-axis direction is determined as a range where the rotational phase is shifted by 90° relative to the cosine wave.

[0060] Figure 8 shows the geometric deviation [mm] between the involute shape Wr of the involute tooth surface Wb and the motion trajectory Tr2 of the cutting edge Tb3 of the grinding wheel Tb, with respect to the phase [°] of the workpiece W at the involute tooth surface Wb (corresponding to the position [mm] in the tooth height direction at the involute tooth surface Wb). It also shows the correction amount X [mm] of the rotary tool T in the X-axis direction relative to the workpiece W, due to the temporal change in the amplitude of the cosine wave within the range including the extreme value, with respect to the phase of the workpiece W at the involute tooth surface Wb. There is a slight phase difference between the pre-correction deviation and the correction amount X.

[0061] Figure 9 shows the pre-correction displacement [mm] and the post-correction displacement [mm] after correcting the rotational tool T in the X-axis direction relative to the workpiece W by the temporal change in amplitude within the range including the extremum of the cosine wave. The post-correction displacement represents the error between the pre-correction displacement (geometric displacement) and the correction amount X in Figure 8. However, the post-correction displacement occurs in a state where it fluctuates between the positive and negative sides near the position where the displacement in the tooth thickness direction is zero. The fluctuation range of the post-correction displacement is smaller than that of the pre-correction displacement, and sufficient correction effect can be obtained even when correcting the geometric displacement by the temporal change in amplitude within the range including the extremum of the cosine wave. This makes it possible to obtain the desired involute tooth surface Wb.

[0062] The relative movement of the rotary tool T relative to the workpiece W in the X-axis direction is performed in a state where it reciprocates periodically while the workpiece W is rotating once. In other words, during machining, the relative movement of the rotary tool T relative to the workpiece W in the X-axis direction is performed in such a way that the periodic change in the amplitude of the cosine wave is continuous. Figure 7 shows the rotation of the workpiece W as a rotation phase from 0° to 360°. In Figure 7, during one rotation of the workpiece W, the range of rotation phase θH[°] during machining repeatedly appears, and the machining of the involute tooth surface Wb by the grinding wheel Tb is repeatedly performed. Even when the grinding wheel Tb is not machining the involute tooth surface Wb, the relative movement of the rotary tool T relative to the workpiece W in the X-axis direction continues. This configuration makes it easy to control the relative movement of the rotary tool T relative to the workpiece W in the X-axis direction.

[0063] Furthermore, the relative movement of the rotary tool T with respect to the workpiece W in the X-axis direction may be performed such that the relative movement speed of the grinding wheel Tb with respect to the involute tooth surface Wb changes continuously before and after the grinding wheel Tb contacts the involute tooth surface Wb, and before and after the grinding wheel Tb separates from the involute tooth surface Wb. This configuration also makes it easier to control the relative movement of the rotary tool T with respect to the workpiece W in the X-axis direction.

[0064] When polishing or grinding an involute tooth surface Wb, after correcting for geometric deviation, the initial machining phase between the convex tooth Wc of the workpiece W and the grinding wheel Tb of the rotary tool T should be set taking into account the polishing or cutting allowance.

[0065] 5-2.Second example A second example of positional displacement correction involves reciprocating the rotary tool T relative to the workpiece W in the X-axis direction so that the geometric displacement is zero within the machining range of the involute tooth surface Wb. The involute shape Wr of the involute tooth surface Wb and the motion trajectory Tr2, which is the cycloidal trajectory of the cutting edge Tb3 of the grinding wheel Tb relative to the workpiece W, are calculated from the geometric positional relationship between the two. Then, the amount of correction for the relative movement of the rotary tool T in the X-axis direction relative to the workpiece W is determined according to the difference between the X-axis position of the involute shape Wr and the X-axis position of the motion trajectory Tr2 in the calculation. When machining each position of the involute tooth surface Wb with the grinding wheel Tb, the amount of correction for the rotary tool T relative to the workpiece W in the X-axis direction is reduced to nearly zero within the machining range of the involute tooth surface Wb by the amount of the correction at each position.

[0066] The geometric displacement is calculated at multiple positions set at appropriate intervals within the machining range of the involute tooth surface Wb. In other words, the geometric displacement is calculated as a point cloud within the machining range of the involute tooth surface Wb. The correction amount for relative movement of the rotary tool T in the X-axis direction relative to the workpiece W is determined so that the geometric displacement is zero at multiple positions on the involute tooth surface Wb. The appropriate intervals can be predetermined time intervals, predetermined intervals in the phase of the workpiece W on the involute tooth surface Wb (angular position in the circumferential direction E), predetermined intervals in the radial position (tooth height direction) of the involute tooth surface Wb, etc.

[0067] When the grinding wheel Tb begins machining at the tooth root position Wb1 of the involute tooth surface Wb, the geometric deviation is large, and the correction amount in the X-axis direction of the motion trajectory Tr2 relative to the involute shape Wr is large. It is difficult to rapidly increase the relative movement of the rotary tool T relative to the workpiece W in the X-axis direction. Therefore, the relative movement of the rotary tool T relative to the workpiece W is started before the grinding wheel Tb begins contact with the involute tooth surface Wb. Then, the relative movement speed of the grinding wheel Tb in the X-axis direction relative to the involute tooth surface Wb is continuously changed before and after the grinding wheel Tb begins contact with the involute tooth surface Wb. This configuration makes it easy to control the relative movement of the rotary tool T relative to the workpiece W in the X-axis direction.

[0068] Figure 10, like Figure 8, shows the pre-correction displacement [mm], as well as the correction amount X [mm] for the rotary tool T in the X-axis direction relative to the workpiece W, when the geometric displacement of the workpiece W with respect to the phase at the involute tooth surface Wb of the workpiece W is set to zero within the machining range of the involute tooth surface Wb. The correction amount X is determined so that the pre-correction displacement is set to zero.

[0069] Figure 11 shows the pre-correction displacement [mm] and the post-correction displacement [mm] after correcting the rotation tool T in the X-axis direction relative to the workpiece W so that the geometric displacement is zero within the machining range of the involute tooth surface Wb. The post-correction displacement is almost zero. This makes it possible to obtain the desired involute tooth surface Wb.

[0070] 5-3. Third example A third example of positional displacement correction involves using the time-dependent change in a range of values ​​that includes the extrema of a quadratic function to correct the relative movement of the rotary tool T in the X-axis direction relative to the workpiece W. The geometric displacement is not zero in at least a portion of the machining range of the involute tooth surface Wb. The curvilinear change in the geometric displacement between the involute shape Wr of the involute tooth surface Wb and the motion trajectory Tr2 of the cutting edge Tb3 of the grinding wheel Tb approximates the curvilinear change in a range that includes the extrema of a quadratic function. The change in a quadratic function is also a continuous, curvilinear change. Therefore, by utilizing the change in a quadratic function, the relative movement of the rotary tool T in the X-axis direction relative to the workpiece W can be made simple and smooth.

[0071] The amount of correction for the rotary tool T in the X-axis direction relative to the workpiece W, due to the temporal change in the value of the range containing the extrema of the quadratic function, may be determined based on the following formula. In this case, when the coefficient of the quadratic function is B [mm], the rotational phase of the workpiece W is θ [°], and the amount of adjustment of the rotational phase of the workpiece W is Δθb [°], the correction amount X [mm] in the X-axis direction is given by X = B × (θ - Δθb). 2 The decision should be based on the following: B and Δθb are constants, while θ and X are variables. Furthermore, the range of rotational phase used for correction in the X-axis direction during machining is set as an appropriate range including the extreme values.

[0072] Even when reciprocating in such a way that the geometric displacement is zero, and when utilizing the temporal change in values ​​within a range that includes the extrema of a quadratic function, the relative movement of the rotary tool T with respect to the workpiece W in the X-axis direction may be performed such that the relative movement speed of the grinding wheel Tb in the X-axis direction with respect to the involute tooth surface Wb changes continuously before and after the grinding wheel Tb contacts the involute tooth surface Wb, and before and after the grinding wheel Tb separates from the involute tooth surface Wb.

[0073] Furthermore, in cases where the reciprocating motion is performed so that the geometric displacement is zero, and in cases where the temporal change of values ​​within a range including the extrema of a quadratic function is utilized, the other configurations are the same as in cases where the temporal change of amplitude within a range including the extrema of a cosine wave is utilized.

[0074] 5-4.Fourth example A fourth example of positional misalignment correction involves moving the rotary tool T relative to the workpiece W in the X-axis direction to reduce the variation in machining resistance applied to the grinding wheel Tb from multiple positions on the involute tooth surface Wb. When the amount of deviation of the movement trajectory Tr2 of the cutting edge Tb3 of the grinding wheel Tb relative to the involute shape Wr of the involute tooth surface Wb is not very large, correction based on variation in machining resistance is effective.

[0075] In the fourth example, during the machining measurement before polishing or grinding, the machining resistance in the normal direction at multiple positions on the involute tooth surface Wb is measured during the polishing or grinding process for measurement. The machining resistance can be measured by various methods. For example, the change in the driving force of the drive device in the X-axis direction in the gear machining apparatus 1 shown in Figure 1 can be used to measure the machining resistance. This is because, in this embodiment, when machining each position on the involute tooth surface Wb, the normal direction of each machining position is configured to coincide almost with the X-axis direction. To measure the machining resistance in the normal direction with higher accuracy, in addition to the change in the driving force of the drive device in the X-axis direction, the change in the driving force of the drive device in the Y-axis direction can also be used. Furthermore, the change in torque of the rotary motor that drives the rotation of the workpiece W, the change in torque of the rotary motor that drives the rotation of the rotary tool T, and measuring instruments such as strain gauges installed on the grinding wheel Tb may also be used to measure the machining resistance.

[0076] When measuring the machining resistance applied from the involute tooth surface Wb to the grinding wheel Tb, a larger polishing or grinding allowance is set, creating a state in which the grinding wheel Tb in contact with the involute tooth surface Wb undergoes elastic deformation. Then, when performing the polishing or grinding for measurement, the machining resistance measured at multiple positions between the tooth root position Wb1 and the tooth tip position Wb3 of the involute tooth surface Wb changes.

[0077] Figure 12 shows the results of measuring the machining resistance in the normal direction of the involute tooth surface Wb with respect to the phase [°] of the workpiece W at the involute tooth surface Wb (corresponding to the position [mm] in the tooth height direction on the involute tooth surface Wb) during machining measurement, as the uncorrected machining resistance [N]. The machining resistance is small near the tooth root position Wb1 and the tooth tip position Wb3 of the involute tooth surface Wb, and large near the intermediate position Wb2 of the involute tooth surface Wb. This change in machining resistance occurs as a variation in machining resistance at each position of the involute tooth surface Wb.

[0078] The lower the machining resistance, the more correction is needed to bring the grinding wheel Tb closer to the involute tooth surface Wb. More specifically, if we take the machining resistance at the intermediate position Wb2 of the involute tooth surface Wb, where the machining resistance is greatest, as the maximum machining resistance, then the lower the machining resistance is compared to the maximum machining resistance, the more correction is needed to bring the grinding wheel Tb closer to the involute tooth surface Wb. When the grinding wheel Tb machines each position of the involute tooth surface Wb, the correction amount, which is the relative movement of the rotary tool T in the X-axis direction relative to the workpiece W, is larger at the tooth root position Wb1 and tooth tip position Wb3 compared to the intermediate position Wb2 of the involute tooth surface Wb.

[0079] During polishing or grinding operations, the rotary tool T is moved relative to the workpiece W in the X-axis direction, which is perpendicular to the rotation axis of the rotary tool T, in order to reduce variations in machining resistance at multiple positions. At this time, the relative movement of the rotary tool T in the X-axis direction relative to the workpiece W is performed based on a correction amount corresponding to the variation in machining resistance. Furthermore, the relative movement of the rotary tool T in the X-axis direction relative to the workpiece W is performed in a state in which the grinding wheel Tb reciprocates as it contacts the involute tooth surface Wb located on one side of the circumferential direction E of the workpiece W, from the tooth root position Wb1 to the tooth tip position Wb3, according to the correction amount.

[0080] Figure 12 also shows the corrected machining resistance [N] when the rotary tool T is moved relative to the workpiece W in the X-axis direction so that the machining resistance in the normal direction is constant at each phase of the workpiece W on the involute tooth surface Wb of the workpiece W during machining. During machining, by rotating the workpiece W and the rotary tool T synchronously and moving the rotary tool T relative to the workpiece W in the X-axis direction, the machining resistance becomes almost uniform and equal to the machining resistance at the intermediate position Wb2, making it possible to obtain the desired involute tooth surface Wb.

[0081] Figure 13 shows a flowchart of the fourth example of a gear machining method. In step S101, the machining resistance in the normal direction is measured at multiple positions on the involute tooth surface Wb during machining measurement. Next, in step S102, a correction amount is determined for the relative movement of the rotary tool T in the X-axis direction relative to the workpiece W according to the machining resistance in the normal direction, and this correction amount is created and stored as axis movement data D2. Next, in step S103, during machining, when the grinding wheel Tb machines each position on the involute tooth surface Wb based on the synchronous rotation data D1, the rotary tool T is moved relative to the workpiece W in the X-axis direction based on the axis movement data D2 to perform the actual machining.

[0082] 5-5.Fifth example The fifth example of positional misalignment correction involves moving the rotary tool T relative to the workpiece W in the X-axis direction, based on both the geometric misalignment shown in the first to third examples and the variation in machining resistance shown in the fourth example. In the fifth example as well, the machining resistance in the normal direction at multiple positions on the involute tooth surface Wb is measured during machining measurement. Then, during machining, the rotary tool T is moved relative to the workpiece W in the X-axis direction, which is perpendicular to the rotation axis Ct of the rotary tool T, in order to reduce the geometric misalignment between the involute shape Wr of the involute tooth surface Wb and the cycloidal trajectory of the grinding wheel Tb relative to the workpiece W, and to reduce the variation in machining resistance at multiple positions on the involute tooth surface Wb.

[0083] The fifth example is effective when simply correcting for geometric deviation is insufficient because the grinding wheel Tb undergoes elastic deformation. In the fifth example, by combining the correction of geometric deviation with the correction of variations in machining resistance, the grinding wheel Tb can be machined more appropriately on the involute tooth surface Wb.

[0084] 6. Effects of the Embodiment In the gear machining method and gear machining apparatus 1 of this embodiment, the cycloidal trajectory of the grinding wheel Tb relative to the workpiece W is corrected so that it approaches the involute shape Wr of the involute tooth surface Wb. Specifically, when polishing or grinding the involute tooth surface Wb on the workpiece W with the grinding wheel Tb of the rotary tool T, the rotary tool T is moved relative to the workpiece W in the X-axis direction. This corrects the discrepancy between the involute shape Wr of the involute tooth surface Wb and the cycloidal trajectory of the grinding wheel Tb relative to the workpiece W to be small.

[0085] Therefore, according to the gear machining method and gear machining apparatus 1 of this embodiment, when polishing or grinding an involute tooth surface Wb by the cycloidal trajectory of the grinding wheel Tb with respect to the workpiece W, a desired involute tooth surface Wb can be obtained. [Explanation of Symbols]

[0086] W Workpiece Wb Involute tooth surface Tb whetstone T Rotary tool Cw Rotation axis of the workpiece Ct Rotation axis of rotary tool Wr Involute Shape Tr1,Tr2 motion trajectory (cycloid trajectory)

Claims

1. A gear machining method for polishing or grinding the involute tooth surface of a gear-shaped workpiece, A machining method is provided in which a rotary tool equipped with one or more grinding wheels protruding radially outward is used, and the workpiece and the rotary tool are rotated synchronously with the rotation axis of the workpiece and the rotation axis of the rotary tool positioned parallel to each other, thereby making the trajectory of the grinding wheel relative to the workpiece a cycloidal trajectory, and the polishing or grinding of the involute tooth surface is performed by the cycloidal trajectory of the grinding wheel relative to the workpiece. A gear machining method, in which, during the polishing or grinding process, the rotary tool is moved relative to the workpiece in a direction perpendicular to the rotation axis of the rotary tool in order to reduce the amount of geometric deviation between the involute shape of the involute tooth surface and the cycloidal trajectory of the grinding wheel with respect to the workpiece.

2. The gear machining method according to claim 1, wherein the relative movement of the rotary tool with respect to the workpiece is performed in a state of reciprocating motion such that the geometric displacement is zero within the machining range of the involute tooth surface.

3. The gear machining method according to claim 1, wherein the relative movement of the rotary tool with respect to the workpiece is performed by utilizing the temporal change in amplitude within a range that includes the extreme value of a cosine wave, rather than making the geometric displacement amount zero in at least a portion of the machining range of the involute tooth surface.

4. The gear machining method according to claim 1, wherein the relative movement of the rotary tool with respect to the workpiece is performed by utilizing the temporal change in the value of a quadratic function within a range that includes an extremum, rather than making the geometric displacement amount zero in at least a portion of the machining range of the involute tooth surface.

5. A gear machining method for polishing or grinding the involute tooth surface of a gear-shaped workpiece, A machining method is provided in which a rotary tool equipped with one or more grinding wheels protruding radially outward is used, and the workpiece and the rotary tool are rotated synchronously with the rotation axis of the workpiece and the rotation axis of the rotary tool positioned parallel to each other, thereby making the trajectory of the grinding wheel relative to the workpiece a cycloidal trajectory, and the polishing or grinding of the involute tooth surface is performed by the cycloidal trajectory of the grinding wheel relative to the workpiece. During the polishing or grinding process, the rotary tool is moved relative to the workpiece in a direction perpendicular to the rotation axis of the rotary tool. A gear machining method in which the relative movement of the rotating tool with respect to the workpiece is performed in a state in which the grinding wheel reciprocates as it contacts the involute tooth surface located on one side of the circumferential direction of the workpiece, moving from the tooth root position to the tooth tip position.

6. A gear machining method for polishing or grinding the involute tooth surface of a gear-shaped workpiece, A machining method is provided in which a rotary tool equipped with one or more grinding wheels protruding radially outward is used, and the workpiece and the rotary tool are rotated synchronously with the rotation axis of the workpiece and the rotation axis of the rotary tool positioned parallel to each other, thereby making the trajectory of the grinding wheel relative to the workpiece a cycloidal trajectory, and the polishing or grinding of the involute tooth surface is performed by the cycloidal trajectory of the grinding wheel relative to the workpiece. During the machining measurement before performing the polishing or grinding process, the machining resistance in the normal direction at multiple positions on the involute tooth surface is measured during the polishing or grinding process for measurement. A gear machining method comprising moving the rotary tool relative to the workpiece in a direction perpendicular to the rotation axis of the rotary tool in order to reduce the variation in the machining resistance at the multiple positions during the polishing or grinding process.

7. A gear machining method for polishing or grinding the involute tooth surface of a gear-shaped workpiece, A machining method is provided in which a rotary tool equipped with one or more grinding wheels protruding radially outward is used, and the workpiece and the rotary tool are rotated synchronously with the rotation axis of the workpiece and the rotation axis of the rotary tool positioned parallel to each other, thereby making the trajectory of the grinding wheel relative to the workpiece a cycloidal trajectory, and the polishing or grinding of the involute tooth surface is performed by the cycloidal trajectory of the grinding wheel relative to the workpiece. During the machining measurement before performing the polishing or grinding process, the machining resistance in the normal direction at multiple positions on the involute tooth surface is measured during the polishing or grinding process for measurement. A gear machining method, in which, during the polishing or grinding process, the rotary tool is moved relative to the workpiece in a direction perpendicular to the rotation axis of the rotary tool in order to reduce the amount of geometric deviation between the involute shape of the involute tooth surface and the cycloidal trajectory of the grinding wheel relative to the workpiece, and to reduce the variation in the machining resistance at the multiple positions.

8. A gear machining method for polishing or grinding the involute tooth surface of a gear-shaped workpiece, A machining method is provided in which a rotary tool equipped with one or more grinding wheels protruding radially outward is used, and the workpiece and the rotary tool are rotated synchronously with the rotation axis of the workpiece and the rotation axis of the rotary tool positioned parallel to each other, thereby making the trajectory of the grinding wheel relative to the workpiece a cycloidal trajectory, and the polishing or grinding of the involute tooth surface is performed by the cycloidal trajectory of the grinding wheel relative to the workpiece. During the polishing or grinding process, the rotary tool is moved relative to the workpiece in a direction perpendicular to the rotation axis of the rotary tool. A gear machining method in which the relative movement of the rotating tool with respect to the workpiece is performed in a state in which the tool periodically reciprocates while the workpiece is rotating once.

9. A gear machining method for polishing or grinding the involute tooth surface of a gear-shaped workpiece, A machining method is provided in which a rotary tool equipped with one or more grinding wheels protruding radially outward is used, and the workpiece and the rotary tool are rotated synchronously with the rotation axis of the workpiece and the rotation axis of the rotary tool positioned parallel to each other, thereby making the trajectory of the grinding wheel relative to the workpiece a cycloidal trajectory, and the polishing or grinding of the involute tooth surface is performed by the cycloidal trajectory of the grinding wheel relative to the workpiece. During the polishing or grinding process, the rotary tool is moved relative to the workpiece in a direction perpendicular to the rotation axis of the rotary tool. A gear machining method, wherein the relative movement of the rotating tool with respect to the workpiece is performed such that the relative movement speed of the grinding wheel with respect to the involute tooth surface changes continuously before and after the grinding wheel contacts the involute tooth surface, and before and after the grinding wheel separates from the involute tooth surface.

10. The aforementioned gear-shaped workpiece is an internal gear-shaped workpiece, The gear machining method according to any one of claims 1 to 9, wherein the rotating tool is positioned on the inner circumference side of the workpiece.

11. A gear machining apparatus for polishing or grinding the involute tooth surface of a gear-shaped workpiece, A rotary tool equipped with one or more grinding wheels protruding radially outward, A control device for controlling the operation of the workpiece and the rotary tool, Equipped with, The control device is The system is configured such that the rotation axis of the workpiece and the rotation axis of the rotary tool are positioned parallel to each other, and the workpiece and the rotary tool are rotated synchronously, thereby creating a cycloidal trajectory for the grinding wheel relative to the workpiece, and the polishing or grinding of the involute tooth surface is performed by following the cycloidal trajectory of the grinding wheel relative to the workpiece. Furthermore, during the polishing or grinding process, the gear machining apparatus is configured to move the rotary tool relative to the workpiece in a direction perpendicular to the rotation axis of the rotary tool in order to reduce the amount of geometric deviation between the involute shape of the involute tooth surface and the cycloidal trajectory of the grinding wheel relative to the workpiece.

12. A gear processing apparatus for polishing or grinding the involute tooth surface of a gear-shaped workpiece, A rotary tool equipped with one or more grinding wheels protruding radially outward, A control device for controlling the operation of the workpiece and the rotary tool, Equipped with, The control device is The system is configured such that the rotation axis of the workpiece and the rotation axis of the rotary tool are positioned parallel to each other, and the workpiece and the rotary tool are rotated synchronously, thereby creating a cycloidal trajectory for the grinding wheel relative to the workpiece, and the polishing or grinding of the involute tooth surface is performed by following the cycloidal trajectory of the grinding wheel relative to the workpiece. During the polishing or grinding process, the rotary tool is configured to move relative to the workpiece in a direction perpendicular to the rotation axis of the rotary tool. A gear machining apparatus, wherein the relative movement of the rotating tool with respect to the workpiece is performed in a reciprocating motion when the grinding wheel contacts the involute tooth surface located on one side of the circumferential direction of the workpiece, moving from the tooth root position to the tooth tip position.

13. A gear processing apparatus for polishing or grinding the involute tooth surface of a gear-shaped workpiece, A rotary tool equipped with one or more grinding wheels protruding radially outward, A control device for controlling the operation of the workpiece and the rotary tool, Equipped with, The control device is The system is configured such that the rotation axis of the workpiece and the rotation axis of the rotary tool are positioned parallel to each other, and the workpiece and the rotary tool are rotated synchronously, thereby creating a cycloidal trajectory for the grinding wheel relative to the workpiece, and the polishing or grinding of the involute tooth surface is performed by following the cycloidal trajectory of the grinding wheel relative to the workpiece. During the machining measurement before performing the polishing or grinding process, the system is configured to measure the machining resistance in the normal direction at multiple positions on the involute tooth surface during the polishing or grinding process for measurement. Furthermore, the gear machining apparatus is configured such that, during the polishing or grinding process, the rotary tool is moved relative to the workpiece in a direction perpendicular to the rotation axis of the rotary tool in order to reduce the variation in the machining resistance at the multiple positions.

14. A gear processing apparatus for polishing or grinding the involute tooth surface of a gear-shaped workpiece, A rotary tool equipped with one or more grinding wheels protruding radially outward, A control device for controlling the operation of the workpiece and the rotary tool, Equipped with, The control device is The system is configured such that the rotation axis of the workpiece and the rotation axis of the rotary tool are positioned parallel to each other, and the workpiece and the rotary tool are rotated synchronously, thereby creating a cycloidal trajectory for the grinding wheel relative to the workpiece, and the polishing or grinding of the involute tooth surface is performed by following the cycloidal trajectory of the grinding wheel relative to the workpiece. During the machining measurement before performing the polishing or grinding process, the system is configured to measure the machining resistance in the normal direction at multiple positions on the involute tooth surface during the polishing or grinding process for measurement. Furthermore, during the polishing or grinding process, the gear machining apparatus is configured to move the rotary tool relative to the workpiece in a direction perpendicular to the rotation axis of the rotary tool in order to reduce the amount of geometric deviation between the involute shape of the involute tooth surface and the cycloidal trajectory of the grinding wheel relative to the workpiece, and to reduce the variation in the machining resistance at the multiple positions.

15. A gear processing apparatus for polishing or grinding the involute tooth surface of a gear-shaped workpiece, A rotary tool equipped with one or more grinding wheels protruding radially outward, A control device for controlling the operation of the workpiece and the rotary tool, Equipped with, The control device is The system is configured such that the rotation axis of the workpiece and the rotation axis of the rotary tool are positioned parallel to each other, and the workpiece and the rotary tool are rotated synchronously, thereby creating a cycloidal trajectory for the grinding wheel relative to the workpiece, and the polishing or grinding of the involute tooth surface is performed by following the cycloidal trajectory of the grinding wheel relative to the workpiece. During the polishing or grinding process, the rotary tool is configured to move relative to the workpiece in a direction perpendicular to the rotation axis of the rotary tool. A gear machining apparatus, wherein the relative movement of the rotating tool with respect to the workpiece is configured to be performed in a state in which the tool periodically reciprocates while the workpiece is rotating once.

16. A gear processing apparatus for polishing or grinding the involute tooth surface of a gear-shaped workpiece, A rotary tool equipped with one or more grinding wheels protruding radially outward, A control device for controlling the operation of the workpiece and the rotary tool, Equipped with, The control device is The system is configured such that the rotation axis of the workpiece and the rotation axis of the rotary tool are positioned parallel to each other, and the workpiece and the rotary tool are rotated synchronously, thereby creating a cycloidal trajectory for the grinding wheel relative to the workpiece, and the polishing or grinding of the involute tooth surface is performed by following the cycloidal trajectory of the grinding wheel relative to the workpiece. During the polishing or grinding process, the rotary tool is configured to move relative to the workpiece in a direction perpendicular to the rotation axis of the rotary tool. A gear machining apparatus, wherein the relative movement of the rotating tool with respect to the workpiece is configured such that the relative movement speed of the grinding wheel with respect to the involute tooth surface changes continuously before and after the grinding wheel contacts the involute tooth surface, and before and after the grinding wheel separates from the involute tooth surface.

Images