Gear machining apparatus and hobbing assembly

Abstract

The utility model relates to gear processing device and hobbing assembly. Gear processing device is used to form multiple helical gears (120) in work piece (100), have: hobbing assembly (200), including hobbing axle (210) and multiple hobbing parts (230, 240), the hobbing axle has hobbing rotation axis (C2), and multiple hobbing parts are set up in the hobbing axle with each other apart interval, the hobbing retaining portion (20) is kept as can rotate to the hobbing assembly, the work piece retaining portion (30) has work piece rotation axis (C1), and the work piece is kept as can rotate, and the control unit (300) controls the posture of hobbing assembly, to make work piece rotation axis and the relationship of hobbing rotation axis become accurate orthogonal, and through parallel movement control of parallel movement of hobbing assembly relative to work piece rotation axis and quasi parallel movement control of quasi parallel movement control at least one control hobbing assembly's movement.

Description

Technical Field

[0001] This utility model relates to a gear processing device and a gear hobbing assembly. Background Technology

[0002] Gear machining apparatuses that utilize gear scraping tools for gear scraping are known. For example, the gear machining apparatus described in Patent Document 1 generates a gear on a workpiece by rotating the gear scraping tool and moving them relative to each other.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2022-182378 Utility Model Content

[0006] The problem to be solved by utility models

[0007] Preferably, multiple helical gears can be effectively formed on the circumferential surface of a workpiece.

[0008] Solution for solving the problem

[0009] The gear processing apparatus according to Solution 1 of this utility model is used to form multiple helical gears on a workpiece. The gear processing apparatus includes: a hobbing assembly, including a hobbing shaft and multiple hobbing portions, the hobbing shaft having a hobbing rotation axis, and the multiple hobbing portions being disposed on the hobbing shaft at intervals; a hobbing holding portion for holding the hobbing assembly so that it can rotate; a workpiece holding portion having a workpiece rotation axis and holding the workpiece so that it can rotate; and a control portion for controlling the posture of the hobbing assembly so that the relationship between the workpiece rotation axis and the hobbing rotation axis is quasi-orthogonal, and controlling the movement of the hobbing assembly by at least one of parallel movement control and quasi-parallel movement control relative to the workpiece rotation axis.

[0010] According to the gear processing apparatus of Scheme 2 of this utility model, in the gear processing apparatus of Scheme 1, preferably, the plurality of helical gears include: a first helical gear having a first pitch circle diameter; and a second helical gear disposed above or below the first helical gear in the vertical direction, and having a second pitch circle diameter greater than the first pitch circle diameter. The plurality of hobbing portions include a first hobbing portion for forming the first helical gear and a second hobbing portion for forming the second helical gear. The control unit controls the hobbing assembly by at least one of parallel movement and quasi-parallel movement of the hobbing assembly relative to the rotation axis of the workpiece in the quasi-orthogonal relationship, so that the first hobbing portion forms the first helical gear on the workpiece.

[0011] The hobbing assembly according to Scheme 3 of this utility model is used to form multiple helical gears on a workpiece. The hobbing assembly includes: a hobbing shaft having a hobbing rotation axis; a first hobbing portion disposed on the hobbing shaft and used to form a first helical gear on the workpiece; and a second hobbing portion disposed on the hobbing shaft at a distance from the first hobbing portion and used to form a second helical gear on the workpiece. When the hobbing assembly is viewed from the direction of the hobbing shaft, which is the direction along the hobbing rotation axis, the number of second cutters in the circumferential direction of the second hobbing portion is an integer multiple of the number of first cutters in the circumferential direction of the first hobbing portion. The phase of the second cutter is different from the phase of the first cutter. The lead angle of the first cutter is set such that at least one of the multiple helical gears can be formed when the posture of the hobbing assembly is controlled such that the relationship between the hobbing rotation axis of the hobbing shaft and the workpiece rotation axis is quasi-orthogonal.

[0012] According to the gear hobbing assembly of Scheme 4 of this utility model, in the gear hobbing assembly of Scheme 3, preferably, the gear hobbing shaft includes an intermediate non-gearing portion, which is disposed between the first gear hobbing portion and the second gear hobbing portion in the gear hobbing shaft direction. The first gear hobbing portion has a first minimum gear diameter portion and an innermost end portion of the first gear located on the side of the intermediate non-gearing portion in the gear hobbing shaft direction. The first minimum gear diameter portion has a first minimum gear radius, which is the minimum radius of the first gear hobbing portion. The second gear hobbing portion has a second minimum gear diameter portion and an innermost end portion of the second gear located on the side of the intermediate non-gearing portion in the gear hobbing shaft direction. The second minimum gear diameter portion has a second minimum gear radius, which is the minimum radius of the second gear hobbing portion. The diameter is the minimum radius of the second hobbing portion, and is greater than the minimum radius of the first hobbing portion. When the first hobbing grinding wheel used for grinding the first hobbing portion is in a specified position, the length of the line segment connecting the minimum diameter of the first hobbing portion at the innermost end of the first hobbing portion and the rotation axis of the first grinding wheel on the reference section, i.e., the first reference line, is shorter than the length of the line segment connecting the minimum diameter of the second hobbing portion at the innermost end of the second hobbing portion and the rotation axis of the first grinding wheel on the reference section, i.e., the second reference line. The specified position is the position where the grinding wheel of the first hobbing portion begins or ends grinding the first hobbing portion, and is the position where the distance from the rotation axis of the first grinding wheel to the innermost end of the second hobbing portion is the shortest on the reference section.

[0013] According to the gear processing apparatus of embodiment 5 of this utility model, it comprises: a gear hobbing assembly as described in any one of embodiments 3 and 4; a gear hobbing holding part for holding the gear hobbing assembly so as to be rotatable; a workpiece holding part for holding the workpiece so as to be rotatable; and a control part for controlling the movement of the gear hobbing assembly by at least one of parallel movement control and quasi-parallel movement control of the gear hobbing assembly relative to the rotation axis of the workpiece.

[0014] According to Scheme 6 of this utility model, a gear hobbing assembly is used to form a helical gear on a workpiece. The gear hobbing assembly includes: a hobbing shaft having a hobbing rotation axis; and a first hobbing portion disposed on the hobbing shaft and used to form a first helical gear on the workpiece. The lead angle of the first tool of the first hobbing portion is set such that, when the posture of the gear hobbing assembly is controlled such that the relationship between the hobbing rotation axis of the hobbing shaft and the workpiece rotation axis is quasi-orthogonal, the first helical gear can be formed by making at least one of parallel movement and quasi-parallel movement of the gear hobbing assembly relative to the workpiece rotation axis.

[0015] According to the gear hobbing assembly of embodiment 7 of this utility model, in the gear hobbing assembly of embodiment 6, it is preferable to further include a second gear hobbing portion which is disposed at a distance from the first gear hobbing portion on the gear hobbing shaft and is used to form a second helical gear on the workpiece. When the gear hobbing assembly is viewed from the gear hobbing shaft direction, which is the direction along the rotation axis of the gear hobbing, the number of second cutters of the second gear hobbing portion in the circumferential direction is an integer multiple of the number of first cutters of the first gear hobbing portion in the circumferential direction.

[0016] According to the gear hobbing assembly of Scheme 8 of this utility model, in the gear hobbing assembly of Scheme 7, preferably, the phase of the second cutter is different from the phase of the first cutter.

[0017] According to the gear hobbing assembly of embodiment 9 of this utility model, in the gear hobbing assembly of embodiment 8, preferably, the gear hobbing shaft includes an intermediate non-gearing portion, the intermediate non-gearing portion being disposed between the first gear hobbing portion and the second gear hobbing portion in the gear hobbing shaft direction, the first gear hobbing portion having a first minimum gear diameter portion and an innermost end portion of the first gear located on the side of the intermediate non-gearing portion in the gear hobbing shaft direction, the first minimum gear diameter portion having a first minimum gear radius, the first minimum gear radius being the minimum radius of the first gear hobbing portion, the second gear hobbing portion having a second minimum gear diameter portion and an innermost end portion of the second gear located on the side of the intermediate non-gearing portion in the gear hobbing shaft direction, the second minimum gear diameter portion having a second minimum gear radius, the second minimum gear radius being the minimum radius of the second gear hobbing portion. The diameter is the minimum radius of the second hobbing portion, and is greater than the minimum radius of the first hobbing portion. When the first hobbing grinding wheel used for grinding the first hobbing portion is in a specified position, the length of the line segment connecting the minimum diameter of the first hobbing portion at the innermost end of the first hobbing portion and the rotation axis of the first grinding wheel on the reference section, i.e., the first reference line, is shorter than the length of the line segment connecting the minimum diameter of the second hobbing portion at the innermost end of the second hobbing portion and the rotation axis of the first grinding wheel on the reference section, i.e., the second reference line. The specified position is the position where the grinding wheel of the first hobbing portion begins or ends grinding the first hobbing portion, and is the position where the distance from the rotation axis of the first grinding wheel to the innermost end of the second hobbing portion is the shortest on the reference section.

[0018] According to the gear processing apparatus of the present invention 10, it comprises: a gear hobbing assembly as described in any one of embodiments 6 to 9; a gear hobbing holding part for holding the gear hobbing assembly so as to be rotatable; a workpiece holding part for holding the workpiece so as to be rotatable; and a control part for controlling the movement of the gear hobbing assembly by at least one of parallel movement control and quasi-parallel movement control of the gear hobbing assembly relative to the rotation axis of the workpiece.

[0019] According to the above structure, since multiple helical gears are formed on the workpiece using a hobbing assembly, multiple helical gears can be effectively formed on the circumferential surface of a single workpiece compared to forming multiple helical gears on a workpiece using scraping or gear planing. Furthermore, since the workpiece's rotation axis and the hobbing axis are quasi-orthogonal, the possibility of the hobbing assembly contacting a location other than the workpiece's machining area during gear formation is reduced.

[0020] Utility Model Effect

[0021] The gear processing device and gear hobbing assembly of this invention can effectively form multiple helical gears on the circumferential surface of a workpiece. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the gear processing apparatus as viewed from the front of the embodiment.

[0023] Figure 2 It's a bird's-eye view. Figure 1 A schematic diagram of a gear processing device.

[0024] Figure 3 It means Figure 1 A block diagram of the electrical configuration of the gear processing device.

[0025] Figure 4 yes Figure 2 The main view of the gear hobbing component.

[0026] Figure 5 yes Figure 4 Side view of the gear hobbing assembly.

[0027] Figure 6 This indicates grinding using the first hobbing grinding wheel. Figure 4 A schematic diagram of an example of the first hobbing part of a hobbing assembly.

[0028] Figure 7 It means by Figure 3 A flowchart illustrating an example of the control of a gear machining device performed by the control unit. Detailed Implementation

[0029] (Implementation Method)

[0030] Reference Figures 1 to 7 The gear machining method, the gear hobbing assembly 200, and the gear machining apparatus 1 will be described below. Hereinafter, the directions of the gear machining apparatus 1 will be referred to as the first horizontal direction X, the second horizontal direction Y orthogonal to the first horizontal direction X, and the vertical direction Z orthogonal to both the first horizontal direction X and the second horizontal direction Y.

[0031] Gear Machining Equipment

[0032] The gear machining apparatus 1 is used to form a plurality of helical gears 120 on a workpiece 100 by cutting it using a gear hobbing assembly 200. The gear machining apparatus 1 performs cutting on the workpiece 100 by simultaneously rotating the workpiece 100 and the gear hobbing assembly 200 while moving the gear hobbing assembly 200 relative to the workpiece 100. In this embodiment, the gear machining apparatus 1 is a gear hobbing machine.

[0033] like Figure 1 and Figure 2 As shown, the gear processing apparatus 1 includes a main body 10, a gear hobbing holding part 20, and a workpiece holding part 30. The gear hobbing holding part 20 and the workpiece holding part 30 are provided in the main body 10. The main body 10 has a base part 11, a movable part, and a support part 16.

[0034] The base portion 11 is located below the movable portion and the support portion 16 in the vertical direction Z. The base portion 11 supports the movable portion and the support portion 16 from below.

[0035] The support portion 16 extends upward from the main body portion 10. A workpiece holding portion 30 is provided in the support portion 16. The workpiece holding portion 30 holds the workpiece 100 so that it can rotate. The workpiece holding portion 30 has a workpiece holding portion main body 31 and a workpiece rotation axis 32. The workpiece rotation axis 32 is disposed on the workpiece holding portion main body 31 in a manner that allows it to rotate relative to the workpiece holding portion main body 31. The workpiece 100 is mounted on the workpiece rotation axis 32. The rotation axis of the workpiece rotation axis 32 is substantially the same as the workpiece rotation axis C1 described later.

[0036] The movable part includes a first movable part 12, a second movable part 13, a third movable part 14, and a rotating part 15. The first movable part 12 is disposed on the base part 11. The first movable part 12 moves on the base part 11 in the first horizontal direction X. The length direction of the base part 11 is substantially aligned with the first horizontal direction X. The first movable part 12 can move in the first horizontal direction X towards the workpiece 100. The first movable part 12 can also move in the first horizontal direction X away from the workpiece 100.

[0037] The second movable part 13 is provided on the side of the first movable part 12 on the workpiece 100 side. The second movable part 13 moves on the side of the first movable part 12 in the vertical direction Z. The second movable part 13 can move in the vertical direction Z such that the second movable part 13 approaches the base part 11. The second movable part 13 can also move in the vertical direction Z such that the second movable part 13 moves away from the base part 11.

[0038] The third movable part 14 is provided on the side of the second movable part 13 on the workpiece 100 side. The third movable part 14 moves on the side of the second movable part 13 in the vertical direction Z. The third movable part 14 can move parallel to the second horizontal direction Y.

[0039] The rotating part 15 is disposed on the side of the third movable part 14 on the workpiece 100 side. The rotating part 15 has a rotating part rotation axis C3. The rotating part 15 is rotatable about the rotating part rotation axis C3. The rotating part rotation axis C3 extends along the first horizontal direction X.

[0040] The hobbing retainer 20 holds the tool so that it can rotate. It has a hobbing retainer body 21 and a hobbing rotation shaft 22. The hobbing retainer body 21 is provided on the side of the workpiece retainer 30 side of the rotating part 15.

[0041] The gear hobbing rotating shaft 22 is disposed on the gear hobbing holding body 21 in a manner that allows it to rotate relative to the gear hobbing holding body 21. The gear hobbing assembly 200 is mounted on the gear hobbing rotating shaft 22 in a manner that allows it to rotate integrally with the gear hobbing rotating shaft 22. The rotation axis of the gear hobbing rotating shaft 22 is substantially the same as the gear hobbing rotating axis C2 described later.

[0042] like Figures 1 to 3 As shown, each movable part of the gear processing device 1 is driven by a plurality of drive units 40. The plurality of drive units 40 includes a first movable part drive unit 41, a second movable part drive unit 42, a third movable part drive unit 43, a rotating part drive unit 44, a workpiece rotation axis drive unit 45, and a gear hobbing rotation axis drive unit 46. Each drive unit 40 includes an actuator. The actuator includes an electric motor or an electromagnetic motor.

[0043] The first movable part drive unit 41 drives the first movable part 12 to move the first movable part 12 along the first horizontal direction X. The first movable part drive unit 41 is electrically connected to the control unit 300 via wired or wireless means.

[0044] The second movable part drive unit 42 drives the second movable part 13 to move the second movable part 13 in the vertical direction Z. The second movable part drive unit 42 is electrically connected to the control unit 300 via wired or wireless means.

[0045] The third movable part drive unit 43 drives the third movable part 14 to move the third movable part 14 along the second horizontal direction Y. The third movable part drive unit 43 is electrically connected to the control unit 300 via wired or wireless means.

[0046] The rotating part drive unit 44 drives the rotating part 15 to rotate around the rotating part rotation axis C3. The rotating part drive unit 44 is electrically connected to the control unit 300 via wired or wireless means.

[0047] The workpiece rotation axis drive unit 45 drives the workpiece rotation axis 32 to make the workpiece 100 rotate around the workpiece rotation axis C1. The workpiece rotation axis drive unit 45 is electrically connected to the control unit 300 via wired or wireless means.

[0048] The gear hobbing shaft drive unit 46 drives the gear hobbing shaft 22 to rotate around the gear hobbing axis C2. The gear hobbing shaft drive unit 46 is electrically connected to the control unit 300 via wired or wireless means.

[0049] The gear processing device 1 is powered by a power supply source 47. The power supply source 47 supplies power to the control unit 300 and the drive unit 40. The power supply source 47 is, for example, an external power source.

[0050] <workpiece>

[0051] like Figure 1 and Figure 2As shown, the workpiece 100 is held by the workpiece holding part 30 in a vertical direction Z with respect to the workpiece rotation axis C1. The workpiece 100 is mounted on the workpiece rotation shaft 32 in a manner that allows it to rotate about the workpiece rotation axis C1.

[0052] The workpiece 100 includes multiple machining portions 110. Each of the multiple machining portions 110 forms a helical gear 120 via a gear hobbing assembly 200. The helical gear 120 is formed on the outer peripheral surface of the multiple machining portions 110. The multiple machining portions 110 are respectively arranged on the workpiece 100 at intervals from each other in the direction along the workpiece rotation axis C1.

[0053] Multiple machining portions 110 include a minor-diameter machining portion 111 and a major-diameter machining portion 112. The diameter of the minor-diameter machining portion 111 is less than or equal to the diameter of the major-diameter machining portion 112. The minor-diameter machining portion 111 is spaced apart from the major-diameter machining portion 112 on the workpiece 100 in the direction along the workpiece rotation axis C1. The workpiece 100 is fixed to the workpiece rotation axis 32 such that the minor-diameter machining portion 111 is located above or below the major-diameter machining portion 112.

[0054] The plurality of helical gears 120 formed on the workpiece 100 include a first helical gear 121 having a first pitch circle diameter and a second helical gear 122 having a second pitch circle diameter. The second pitch circle diameter is greater than or equal to the first pitch circle diameter. The first helical gear 121 is formed in the small diameter machined portion 111. The second helical gear 122 is formed in the large diameter machined portion 112.

[0055] <Gear Hobbing Assembly>

[0056] like Figure 1 , Figure 2 and Figures 4 to 6 As shown, the gear hobbing assembly 200 includes a gear hobbing shaft 210 and a plurality of gear hobbing portions 220. The plurality of gear hobbing portions 220 are integrally formed with the gear hobbing shaft 210. The plurality of gear hobbing portions 220 are disposed on the outer periphery of the gear hobbing shaft 210.

[0057] The plurality of hobbing portions 220 include a first hobbing portion 230 and a second hobbing portion 240. The first hobbing portion 230 is a hobbing portion for forming a first helical gear 121. The second hobbing portion 240 is a hobbing portion for forming a second helical gear 122. The second hobbing portion 240 is disposed on the hobbing shaft 210 at a predetermined interval from the first hobbing portion 230 in the hobbing axis direction HD.

[0058] The hobbing shaft 210 has a hobbing rotation axis C2. The hobbing shaft 210 is rotatable about the hobbing rotation axis C2. The direction along the hobbing rotation axis C2 is defined as the hobbing axis direction HD. The hobbing axis direction HD includes a first hobbing axis direction HD1 and a second hobbing axis direction HD2. The first hobbing axis direction HD1 is the direction along the hobbing axis direction HD from the second hobbing portion 240 toward the first hobbing portion 230. The second hobbing axis direction HD2 is the direction along the hobbing axis direction HD from the first hobbing portion 230 toward the second hobbing portion 240.

[0059] The gear hobbing shaft 210 includes a first non-hogging portion 211, a second non-hogging portion 212, and an intermediate non-hogging portion 213. The first non-hogging portion 211 is disposed in the gear hobbing axis direction HD, closer to the first gear hogging portion 230 on the side of the first gear hobbing axis direction HD1. The second non-hogging portion 212 is disposed in the gear hobbing axis direction HD, closer to the second gear hogging portion 240 on the side of the second gear hobbing axis direction HD2. The intermediate non-hogging portion 213 is disposed between the first gear hogging portion 230 and the second gear hogging portion 240.

[0060] The first hobbing portion 230 includes an outermost end portion 230A and an innermost end portion 230B of the first hobbing tooth. The outermost end portion 230A of the first hobbing tooth is located on the side of the first non-hobbing portion 2131 in the hobbing axis direction HD. The outermost end portion 230A of the first hobbing tooth is the portion of the outermost end portion of the first hobbing portion 230 on the side of the first hobbing axis direction HD1 relative to the center of the first hobbing portion 230 in the hobbing axis direction HD.

[0061] The innermost end 230B of the first hobbing tooth is located on the side of the middle non-hobbing portion 213 in the hobbing axis direction HD. The innermost end 230B of the first hobbing tooth is the portion of the outermost end of the first hobbing portion 230 on the side of the second hobbing axis direction HD2 relative to the center of the first hobbing portion 230 in the hobbing axis direction HD.

[0062] The first hobbing section 230 has a plurality of first cutting tools 231. The plurality of first cutting tools 231 are arranged in a spiral shape. The lead angle of the first cutting tool 231 is set such that when the posture of the hobbing assembly 200 is controlled such that the workpiece rotation axis C1 and the hobbing rotation axis C2 are quasi-orthogonal, the first helical gear 121 can be formed.

[0063] Quasi-orthogonal means that when the hobbing rotation axis C2 is projected onto an imaginary surface passing through the workpiece rotation axis C1, the workpiece rotation axis C1 and the hobbing rotation axis C2 are orthogonal, or the hobbing rotation axis C2 intersects the workpiece rotation axis C1 at a slight inclination. The imaginary surface is a surface that extends in a direction perpendicular to the workpiece rotation axis C1 and is parallel to the hobbing rotation axis C2.

[0064] When the hobbing rotation axis C2 is projected onto an imaginary plane that is quasi-orthogonal to the workpiece rotation axis C1, and the hobbing rotation axis C2 is slightly inclined relative to the workpiece rotation axis C1, the hobbing rotation axis C2 is inclined at a predetermined angle relative to the workpiece rotation axis C1. The predetermined angle is the angle to which the hobbing assembly 200 does not interfere with the large-diameter machining portion 112 of the workpiece 100 when machining the small-diameter machining portion 111 of the workpiece 100. The predetermined angle is greater than 0° and less than 5°.

[0065] The lead angle of the first tool 231 is, for example, 10° or more and 45° or less. The lead angle of the first tool 231 is, for example, 15°.

[0066] The radius of the reference circle that serves as the reference for the lead angle of the first cutting tool 231 is called the first lead angle reference radius. The first lead angle reference radius is, in the radial direction of the first hobbing section 230, a distance less than or equal to the distance from the rotation axis of the first hobbing section 230 to the bottom of the first cutting tool 231. The first lead angle reference radius may also be, in the radial direction of the first hobbing section 230, longer than the distance from the rotation axis of the first hobbing section 230 to the bottom of the first cutting tool 231, and shorter than the distance from the rotation axis of the first hobbing section 230 to the tip of the first cutting tool 231. The first lead angle reference radius may also be, greater than or equal to the distance from the rotation axis of the first hobbing section 230 to the tip of the first cutting tool 231.

[0067] The first hobbing section 230 includes a first hobbing maximum diameter section 230C. The first hobbing maximum diameter section 230C has a first hobbing maximum radius R11, which is the maximum radius of the first hobbing section 230. The first hobbing maximum radius R11 is the distance from the rotation axis of the first hobbing section 230 to the tip of the first cutting tool 231 in the radial direction of the first hobbing section 230. The first hobbing maximum diameter section 230C includes the tip of the first cutting tool 231.

[0068] The first hobbing section 230 includes a first hobbing minimum diameter section 230D. The first hobbing minimum diameter section 230D has a first hobbing minimum radius R12, which is the minimum radius of the first hobbing section 230. The first hobbing minimum radius R12 is the distance from the rotation axis of the first hobbing section 230 to the bottom of the first cutting tool 231 in the radial direction of the first hobbing section 230. The first hobbing minimum diameter section 230D includes the bottom of the first cutting tool 231.

[0069] The second hobbing portion 240 includes the outermost end portion 240A of the second hobbing tooth and the innermost end portion 240B of the second hobbing tooth. The outermost end portion 230A of the first hobbing tooth is located on the side of the second non-hobbing portion 212 in the hobbing axis direction HD. The outermost end portion 240A of the second hobbing tooth is the portion of the outermost end portion of the second hobbing portion 240 on the side of the second hobbing axis direction HD2 relative to the center of the second hobbing portion 240 in the hobbing axis direction HD.

[0070] The innermost end portion 240B of the second hobbing gear is located on the side of the intermediate non-hobbing portion 213 in the hobbing axis direction HD. The innermost end portion 240B of the second hobbing gear is the portion of the outermost end of the second hobbing portion 240 on the side of the second hobbing axis direction HD2 relative to the center of the second hobbing portion 240. The rotation axis of the second hobbing portion 240 is substantially the same as the hobbing rotation axis C2.

[0071] The second hobbing section 240 has a plurality of second cutting tools 241. The plurality of second cutting tools 241 are arranged in a spiral shape. The lead angle of the second cutting tool 241 is taken as the first angle. The inclination angle of the teeth of the second helical gear 122 is taken as the second angle. The second helical gear 122 can be formed when the posture of the hobbing assembly 200 is controlled such that the hobbing rotation axis C2 is tilted by a third angle relative to the workpiece rotation axis C1. The third angle is the absolute value of the difference between the second angle and the first angle.

[0072] The second hobbing portion 240 includes a second maximum hobbing diameter portion 240C. The second maximum hobbing diameter portion 240C has a second maximum hobbing radius R21, which is the maximum radius of the second hobbing portion 240. The second maximum hobbing radius R21, in the radial direction of the second hobbing portion 240, is the distance from the rotation axis of the second hobbing portion 240 to the tip of the second cutting tool 241. The second maximum hobbing diameter portion 240C includes the tip of the second cutting tool 241.

[0073] The second hobbing portion 240 includes a second hobbing minimum diameter portion 240D. The second hobbing minimum diameter portion 240D has a second hobbing minimum radius R22, which is the minimum radius of the second hobbing portion 240. The second hobbing minimum radius R22 is the distance from the rotation axis of the second hobbing portion 240 to the bottom of the second cutting tool 241 in the radial direction of the second hobbing portion 240. The second hobbing minimum diameter portion 240D includes the bottom of the second cutting tool 241.

[0074] Hereinafter, the length of the line segment connecting the outermost end 230A of the first hob and the innermost end 230B of the first hob is referred to as the first hob length L1. The length of the line segment connecting the outermost end 240A of the second hob and the innermost end 240B of the second hob is referred to as the second hob length L2. The length of the line segment connecting the innermost end 230B of the first hob and the innermost end 240B of the second hob is referred to as the intermediate non-hob length L3.

[0075] The gear hobbing portion ground by the grinding wheel 250 is referred to as the work-in-process gear hobbing portion. The gear hobbing portion adjacent to the work-in-process gear hobbing portion and having a larger diameter than the work-in-process gear hobbing portion is referred to as the adjacent gear hobbing portion. When the work-in-process gear hobbing portion is one of a plurality of gear hobbing portions with a diameter smaller than that of the gear hobbing portion having the largest diameter, the grinding wheel 250 may come into contact with the adjacent gear hobbing portion. In this embodiment, to avoid contact between the grinding wheel 250 and the adjacent gear hobbing portion when grinding the work-in-process gear hobbing portion, the following structure is adopted.

[0076] like Figure 5 As shown, when the hobbing assembly 200 is viewed in the second hobbing axis direction HD2, the number of second cutters 241 in the circumferential direction of the second hobbing portion 240 is an integer multiple of the number of first cutters 231 in the circumferential direction of the first hobbing portion 230. In this embodiment, when the hobbing assembly 200 is viewed in the second hobbing axis direction HD2, the number of second cutters 241 in the circumferential direction of the second hobbing portion 240 is twice the number of first cutters 231 in the circumferential direction of the first hobbing portion 230.

[0077] The phase of the first tool 231 is different from the phase of the second tool 241. When the hobbing assembly 200 is viewed in the direction HD2 of the second hobbing axis, the phase of the first tool 231 is offset clockwise by a specified angle AN relative to the phase of the second tool 241. The specified angle AN is greater than 0° and less than 30°.

[0078] As described above, by making the phase of the first tool 231 different from the phase of the second tool 241, when the first tool 231 is ground using the first hobbing grinding wheel 251, the machining surface of the first hobbing grinding wheel 251 easily contacts only the first tool 231. Therefore, interference between the first hobbing grinding wheel 251 and the second tool 241 can be suppressed.

[0079] like Figure 5 and Figure 6 As shown, the minimum radius R22 of the second hobbing tooth is greater than the minimum radius R12 of the first hobbing tooth. The minimum radius R22 of the second hobbing tooth is greater than the maximum radius R11 of the first hobbing tooth. Figure 6The diagram schematically shows the cross-sections of the first hobbing grinding wheel 251, the first hobbing section 230, and the second hobbing section 240 on a reference section. The reference section is a section parallel to the hobbing axis direction HD.

[0080] The first tool 231 and the second tool 241 have grindable regions, which are areas that can be machined by the grinding wheel 250. The grindable region of the first tool 231 is referred to as the first grindable region. The second grindable region of the second tool 241 is referred to as the second grindable region. The size of the first grindable region is set to be the same as or substantially the same as the size of the second grindable region.

[0081] When the size of the grinding area of ​​the first tool 231 and the second tool 241 is different, the lifespan of each hobbing part is also different. When multiple hobbing parts constitute a hobbing assembly, if the lifespan of each hobbing part is different, the hobbing assembly is discarded based on the hobbing part with the shorter lifespan.

[0082] In this respect, since the first grinding region and the second grinding region are set as described above, the lifespans of the first tool 231 and the second tool 241 can be made close. Therefore, it is possible to avoid the situation where the hobbing assembly 200 must be discarded even though one of the first hobbing section 230 and the second hobbing section 240 can be used.

[0083] <Gear hobbing method>

[0084] Reference Figure 5 and Figure 6 The gear hobbing grinding method is described below. The plurality of first tools 231 in the first gear hobbing section 230 and the plurality of second tools 241 in the second gear hobbing section 240 are each ground by different grinding wheels 250. The grinding wheel 250 used to grind the first tools 231 of the first gear hobbing section 230 is called the first gear hobbing grinding wheel 251. The grinding wheel 250 used to grind the second tools 241 of the second gear hobbing section 240 is called the second gear hobbing grinding wheel. Alternatively, the plurality of first tools 231 and the plurality of second tools 241 of the second gear hobbing section 240 may be ground by the same grinding wheel 250.

[0085] The gear hobbing grinding method includes a first grinding step and a second grinding step. The first grinding step is the step of grinding the tooth surface of the first hobbing section 230. The second grinding step is the step of grinding the tooth surface of the second hobbing section 240. The second grinding step is performed before or after the first grinding step.

[0086] In the first grinding step, the first hobbing grinding wheel 251 moves relative to the first hobbing portion 230 in a manner that grinds the tooth surface of the first hobbing portion 230. The first hobbing grinding wheel 251 moves relative to the first hobbing portion 230 along the hobbing axis direction HD. The first hobbing grinding wheel 251 moves between the outer position P1 and the inner position P2 of the first hobbing portion. The first hobbing grinding wheel 251 starts moving relative to the first hobbing portion 230 from either the outer position P1 or the inner position P2.

[0087] The first hobbing grinding wheel 251 moves from one of the outer hobbing position P1 and the inner hobbing position P2 towards the other. When the first hobbing grinding wheel 251 reaches the other side of the outer hobbing position P1 and the inner hobbing position P2, it reverses its movement direction relative to the first hobbing portion 230. The first hobbing grinding wheel 251 moves from the other side of the outer hobbing position P1 and the inner hobbing position P2 towards one side.

[0088] In the second grinding process, the second hobbing grinding wheel moves relative to the second hobbing portion 240 in a manner that grinds the tooth surface of the second hobbing portion 240. Figure 6 The second hobbing grinding wheel is not shown in the diagram. The second hobbing grinding wheel moves relative to the second hobbing portion 240 in a manner along the hobbing axis direction HD. The second hobbing grinding wheel moves between the outer position and the inner position of the second hobbing tooth. The second hobbing grinding wheel begins to move relative to the second hobbing portion 240 from either the outer position or the inner position of the second hobbing tooth.

[0089] The second hobbing grinding wheel moves from one side of the second hobbing tooth outer position and the second hobbing tooth inner position towards the other. When the second hobbing grinding wheel reaches the other side of the second hobbing tooth outer position and the second hobbing tooth inner position, it reverses the direction of movement relative to the second hobbing tooth portion 240. The second hobbing grinding wheel moves from the other side of the second hobbing tooth outer position and the second hobbing tooth inner position towards one side.

[0090] <Setting the intermediate non-hobbing length>

[0091] The first hobbing grinding wheel 251 has a first grinding wheel rotation axis C4. When the first hobbing grinding wheel 251 is located at the inner position P2 of the first hobbing tooth, the first grinding wheel rotation axis C4 of the grinding wheel 250 is referred to as the first inner center CA4. The first inner center CA4 is located on the side of the second hobbing axis direction HD2 relative to the first hobbing tooth portion 230.

[0092] The line segment connecting the first inner center CA4 and the minimum diameter portion 230D of the first hob 230B on the reference section is called the first reference line LS1. The first reference line LS1 connects the first inner center CA4 and the outer periphery of the minimum diameter portion 230D of the first hob 230B.

[0093] The line segment connecting the first inner center CA4 and the minimum diameter portion 240D of the second hob 240B on the reference section is called the second reference line LS2. The second reference line LS2 connects the first inner center CA4 and the outer periphery of the minimum diameter portion 240D of the second hob 240B.

[0094] When the first hobbing grinding wheel 251 is in a predetermined position, the length of the first reference line LS1 is shorter than the length of the second reference line LS2. The predetermined position is the location where the first hobbing grinding wheel 251 begins or ends grinding the first hobbing portion 230. The predetermined position is the location on the reference section where the distance from the first grinding wheel rotation axis C4 of the first hobbing grinding wheel 251 to the innermost end 240B of the second hobbing tooth of the second hobbing portion 240 is the shortest. In this embodiment, the predetermined position substantially coincides with the inner position P2 of the first hobbing tooth.

[0095] With the length of the first reference line LS1 fixed, the length of the second reference line LS2 varies according to the intermediate non-hogging length L3. As the intermediate non-hogging length L3 increases, the length of the second reference line LS2 also increases. The intermediate non-hogging length L3 is set such that the first reference line LS1 is longer than the second reference line LS2. The intermediate non-hogging length L3 is set to the shortest length at which the first hobbing grinding wheel 251 does not contact the innermost end 240B of the second hobbing tooth of the second hobbing portion 240 when the first hobbing grinding wheel 251 is in a predetermined position.

[0096] <Setting the lengths of the first and second hobbing teeth>

[0097] The first hobbing length L1 and the second hobbing length L2 are respectively set such that when the number of times the workpiece 100 is machined by the first hobbing part 230 and the number of times the workpiece 100 is machined by the second hobbing part 240 are the same, the tool wear rate is substantially equal.

[0098] If the wear rates of the various hobbing sections are different, their lifespans will also differ. Therefore, when multiple hobbing sections constitute a hobbing assembly, the hobbing assembly is discarded based on the hobbing section that reaches the end of its lifespan. For example, the diameter of the first hobbing section 230 is smaller than the diameter of the second hobbing section 240. Therefore, when the lengths of the first hobbing section L1 and the second hobbing section L2 are the same, the first hobbing section 230 is more likely to reach its lifespan first.

[0099] In this respect, since the first hobbing length L1 and the second hobbing length L2 are respectively set as described above, the lifespans of the first hobbing portion 230 and the second hobbing portion 240 can be made similar. Therefore, it is possible to avoid the situation where the hobbing assembly 200 must be discarded even though one of the first hobbing portion 230 and the second hobbing portion 240 can be used.

[0100] The number of cuts made by the first tool 231 when forming a first helical gear 121 is called the first cut. The first cut is determined by the feed rate of the first hobbing section 230 towards the workpiece 100 in the axial direction when machining the first helical gear 121 and the required machining accuracy when machining the first helical gear 121.

[0101] The number of cuts made by the second tool 241 when forming a second helical gear 122 is called the second cut. The second cut is determined by the feed rate of the second hobbing section 240 towards the workpiece 100 in the axial direction when machining the second helical gear 122 and the required machining accuracy when machining the second helical gear 122.

[0102] The ratio of the second hobbing to the first hobbing is essentially the same as the ratio of the second hobbing length L2 to the first hobbing length L1. Therefore, by determining the first and second hobbing, the ratio of the second hobbing length L2 to the first hobbing length L1 is determined.

[0103] The sum of the first hobbing length L1, the intermediate non-hobbing length L3, and the second hobbing length L2 is set based on the hobbing range of the hobbing assembly 200. The hobbing range of the hobbing assembly 200 is determined based on the range of motion of the third movable part 14.

[0104] The first hobbing length L1 and the second hobbing length L2 are set according to the ratio of the sum of the first hobbing length L1, the intermediate non-hobbing length L3, and the second hobbing length L2 to the second hobbing length L2 relative to the first hobbing length L1. In this embodiment, the first hobbing length L1 is longer than the second hobbing length L2.

[0105] <Control Department>

[0106] like Figures 1 to 3 As shown, the gear machining apparatus 1 includes a control unit 300 and a storage unit 301. The control unit 300 includes a processing unit that executes a predetermined control program. The control unit 300 controls each drive unit 40 of the gear machining apparatus 1 in order to form a plurality of helical gears 120 on the workpiece 100. The control unit 300 controls the movement of the hobbing assembly 200 by at least one of parallel movement control and quasi-parallel movement control.

[0107] Parallel movement control is the control unit 300 that causes the gear hobbing assembly 200 to move parallel to the workpiece rotation axis 32. Quasi-parallel movement control is the control unit 300 that causes the gear hobbing assembly 200 to move quasi-parallel to the workpiece rotation axis 32.

[0108] The quasi-parallel movement includes at least one of the following: the gear hobbing assembly 200 moves in a slightly circular arc relative to the workpiece rotation axis 32, and the base gear hobbing assembly 200 moves at a slightly inclined position relative to the workpiece rotation axis 32.

[0109] The operator selects which of the at least one controls, parallel movement control and quasi-parallel movement control, the control unit 300 performs. For example, based on the shape of the workpiece 100 to be processed, the operator inputs instructions for at least one control, parallel movement control and quasi-parallel movement control, into the computer. Alternatively, the control unit 300 itself can select which of the at least one control, parallel movement control and quasi-parallel movement control, is performed based on various information input during the input process.

[0110] The storage unit 301 includes a non-volatile memory and a volatile memory. The storage unit 301 is communicatively connected to the control unit 300 via wired or wireless means. The storage unit 301 stores various information for controlling the gear processing device 1.

[0111] <Gear Machining Methods>

[0112] Reference Figures 1 to 3 and Figure 7 This section describes an example of a gear machining method using the gear machining apparatus 1 of this embodiment. The gear machining method is executed by the control unit 300. The gear machining method includes a calculation process, a shaft position control process, a shaft posture control process, and a gear forming process.

[0113] As a pre-processing stage, an input process is performed. The input process involves the operator inputting information required for machining the workpiece 100 into the computer. This information includes, for example, information about the shape of the helical gear 120 and the shape of the gear hobbing assembly 200. In the input process, the operator inputs instructions for at least one control—for parallel movement control and quasi-parallel movement control—into the computer based on the shape of the workpiece 100 to be machined.

[0114] The calculation process is a process that calculates the information required to process workpiece 100 based on the information input in the input process. In the calculation process, the information required to process each of the multiple helical gears 120 is calculated. In the calculation process, the control unit 300 can also select at least one of parallel movement control and quasi-parallel movement control based on the various information input in the input process.

[0115] The information required for machining workpiece 100 includes information about the movement and orientation of the gear hobbing assembly 200 and information about the rotational speed of workpiece 100. The information about the movement and orientation of the gear hobbing assembly 200 includes the rotational speed of the gear hobbing assembly 200, the moving speed of the gear hobbing assembly 200 in the hobbing axis direction HD, and the tilt angle of the gear hobbing assembly 200 relative to workpiece 100.

[0116] The axis position control process includes a first axis position control process and a second axis position control process. The first axis position control process is performed before the machining of the first helical gear 121 begins. The first axis position control process controls the position of the hobbing assembly 200 in the second horizontal direction Y and the vertical direction Z so that the machining execution part of the first hobbing section 230 is located at a position corresponding to the machining start position of the small diameter machining section 111.

[0117] The machining execution portion of the first hobbing section 230 is any part between the outermost end portion 230A and the innermost end portion 230B of the first hobbing tooth. Each time the workpiece 100 is machined, the machining execution portion of the first hobbing section 230 changes between the outermost end portion 230A and the innermost end portion 230B of the first hobbing tooth. For example, if the area near the innermost end portion 230B of the first hobbing tooth is initially selected as the machining execution portion of the first hobbing section 230, in subsequent machining of the workpiece 100, a portion of the first hobbing section 230 closer to the first hobbing tooth axis direction HD1 than the initial machining execution portion is selected as the machining execution portion.

[0118] Repeat the above process. After the area near the outermost end 230A of the first hob is selected as the machining execution area, the area near the innermost end 230B of the first hob is again selected as the machining execution area of ​​the first hob portion 230. This process is repeated until the first tool 231 of the first hob portion 230 can perform the required number of machining operations.

[0119] Regarding the starting position of machining in the vertical direction Z of the small-diameter machining section 111, one of the positions corresponding to the lowest machining target portion of the small-diameter machining section 111 and the highest machining target portion of the small-diameter machining section 111 is selected. Regarding the ending position of machining in the vertical direction Z of the small-diameter machining section 111, the other of the positions corresponding to the lowest machining target portion of the small-diameter machining section 111 and the highest machining target portion of the small-diameter machining section 111 is selected.

[0120] The second axis position control process is performed before the machining of the second helical gear 122 begins. The second axis position control process controls the position of the hobbing assembly 200 in the second horizontal direction Y and the vertical direction Z so that the machining execution part of the second hobbing part 240 is located opposite the machining start position of the large diameter machining part 112.

[0121] The machining execution portion of the second hobbing section 240 is any part between the outermost end portion 240A of the second hobbing tooth and the innermost end portion 240B of the second hobbing tooth. Each time workpiece 100 is machined, the machining execution portion of the second hobbing section 240 changes between the outermost end portion 240A and the innermost end portion 240B of the second hobbing tooth. For example, if initially the area near the innermost end portion 240B of the second hobbing tooth is selected as the machining execution portion of the second hobbing section 240, in subsequent machining of workpiece 100, the side of the second hobbing section 240 closer to the second hobbing tooth axis direction HD2 than the initial machining execution portion is selected as the machining execution portion.

[0122] Repeat the above process. After the area near the outermost end 240A of the second hobbing gear is selected as the machining execution area, the area near the innermost end 230B of the first hobbing gear is again selected as the machining execution area of ​​the first hobbing gear 230. This process is repeated until the second cutting tool 241 of the second hobbing gear 240 can perform the required number of machining operations.

[0123] Regarding the starting position of machining in the vertical direction Z of the large-diameter machining section 112, one of the positions corresponding to the lowest machining target portion of the large-diameter machining section 112 and the highest machining target portion of the large-diameter machining section 112 is selected. Regarding the ending position of machining in the vertical direction Z of the large-diameter machining section 112, the other of the positions corresponding to the lowest machining target portion of the large-diameter machining section 112 and the highest machining target portion of the large-diameter machining section 112 is selected.

[0124] The axis posture control process includes a first axis posture control process and a second axis posture control process. The first axis posture control process is performed before the machining of the first helical gear 121 begins. The first axis posture control process controls the posture of the hobbing assembly 200 so that the relationship between the workpiece rotation axis C1 of the workpiece 100 and the hobbing rotation axis C2 of the hobbing assembly 200 is quasi-orthogonal.

[0125] The second axis posture control process is performed before the machining of the second helical gear 122 begins. The second axis posture control process is to control the posture of the hobbing assembly 200 so that the hobbing rotation axis C2 of the hobbing assembly 200 is tilted by a third angle relative to the workpiece rotation axis C1 of the workpiece 100.

[0126] In the gear forming process, the control unit 300 performs at least one control of parallel movement control and quasi-parallel movement control. The gear forming process includes a first gear forming process and a second gear forming process. The first gear forming process is a process in which a first helical gear 121 is formed on the workpiece 100 by means of at least one parallel movement and quasi-parallel movement of the hobbing assembly 200, which is in a quasi-orthogonal relationship with the workpiece 100, relative to the workpiece rotation axis C1, using the first hobbing part 230.

[0127] The second gear forming process is a process in which the second helical gear 122 is formed on the workpiece 100 by the second hobbing part 240 using at least one of parallel and quasi-parallel movements of the hobbing assembly 200 relative to the workpiece rotation axis C1 while the hobbing posture is tilted. The hobbing posture tilted state is a state in which the hobbing rotation axis C2 of the hobbing assembly 200 is tilted by a third angle relative to the workpiece rotation axis C1 of the workpiece 100.

[0128] When the control unit 300 receives the start signal for gear machining after the human input process, it proceeds according to... Figure 7 The flowchart shown illustrates the gear machining process. When a start signal for gear machining is received, the control unit 300 executes... Figure 7 The processing of step S11.

[0129] The control unit 300 performs a calculation process in step S11. After performing the calculation process, the control unit 300 moves the process to step S12.

[0130] In step S12, the control unit 300 performs the first axis position control process. After performing the first axis position control process, the control unit 300 moves the process to step S13.

[0131] In step S13, the control unit 300 performs the first-axis posture control process. After performing the first-axis posture control process, the control unit 300 moves the processing to step S14. Steps S12 and S13 can also be performed in an interchangeable order.

[0132] In step S14, the control unit 300 performs the first gear forming process. After performing the first gear forming process, the control unit 300 moves the process to step S15.

[0133] In step S15, the control unit 300 performs the second-axis position control process. After performing the second-axis position control process, the control unit 300 moves the process to step S16.

[0134] In step S16, the control unit 300 performs the second-axis posture control process. After performing the second-axis posture control process, the control unit 300 moves the processing to step S17. Steps S15 and S16 can also be executed in an interchangeable order.

[0135] In step S17, the control unit 300 performs the second gear forming process. After performing the second gear forming process, the control unit 300 ends the process.

[0136] (Effects of the implementation method)

[0137] According to the gear machining method of this embodiment, the hobbing assembly 200 and the gear machining apparatus 1 can achieve the following effects, for example.

[0138] (1) A gear machining method for forming a plurality of helical gears 120 on a workpiece 100, the gear machining method comprising: a shaft posture control step for controlling the posture of a hobbing assembly 200 such that the relationship between the workpiece rotation axis C1 of the workpiece 100 and the hobbing rotation axis C2 of the hobbing assembly 200 is quasi-orthogonal; and a gear forming step for forming helical gears 120 on the workpiece 100 by at least one of parallel movement and quasi-parallel movement of the hobbing assembly 200 relative to the workpiece rotation axis C1, which is in a quasi-orthogonal relationship with the workpiece 100.

[0139] According to the above structure, since multiple helical gears 120 are formed on the workpiece 100 using the hobbing assembly 200, for example, compared to forming multiple helical gears 120 on the workpiece 100 by scraping or gear planing, multiple helical gears 120 can be effectively formed on the circumferential surface of a single workpiece 100. Furthermore, since the workpiece rotation axis C1 and the hobbing rotation axis C2 are quasi-orthogonal in the gear forming process, the possibility of the hobbing assembly 200 contacting a location other than the workpiece 100 during the gear forming process can be reduced.

[0140] (2) The plurality of helical gears 120 includes: a first helical gear 121 having a first pitch circle diameter; and a second helical gear 122 disposed above or below the first helical gear 121 in the vertical direction Z, and having a second pitch circle diameter greater than the first pitch circle diameter. The gear hobbing assembly 200 includes a first hobbing portion 230 and a second hobbing portion 240, the first hobbing portion 230 being used to form the first helical gear 121, and the second hobbing portion 240 being used to form the second helical gear 122. The gear forming process includes the following steps: by moving the gear hobbing assembly 200, which is in a quasi-orthogonal relationship with the workpiece 100, at least one of parallel movement and quasi-parallel movement relative to the workpiece rotation axis C1, the first helical gear 121 is formed on the workpiece 100 using the first hobbing portion 230.

[0141] According to the above structure, by moving the hobbing assembly 200, which is in a quasi-orthogonal relationship, at least one of its parallel and quasi-parallel movements relative to the workpiece rotation axis C1, a plurality of helical gears 120 can be formed on the circumferential surface of a workpiece 100 using the first hobbing portion 230. Therefore, the first hobbing portion 230 is less likely to interfere with the second helical gear 122. Thus, a plurality of helical gears 120 can be effectively formed on the circumferential surface of a workpiece 100.

[0142] (3) A gear hobbing assembly 200 for forming a plurality of helical gears 120 on a workpiece 100, the gear hobbing assembly 200 comprising: a hobbing shaft 210 having a hobbing rotation axis C2; a first hobbing portion 230 disposed on the hobbing shaft 210 for forming a first helical gear 121 on the workpiece 100; and a second hobbing portion 240 disposed on the hobbing shaft 210 at a distance from the first hobbing portion 230 for forming a second helical gear 122 on the workpiece 100. When the gear hobbing assembly 200 is viewed from the hobbing shaft direction HD, which is the direction along the hobbing rotation axis C2, the number of second cutters 241 in the circumferential direction of the second hobbing portion 240 is an integer multiple of the number of first cutters 231 in the circumferential direction of the first hobbing portion 230. The phase of the second cutter 241 is different from the phase of the first cutter 231. The lead angle of the first cutting tool 231 is set such that, when the posture of the hobbing assembly 200 is controlled such that the relationship between the hobbing rotation axis C2 of the hobbing assembly 200 and the workpiece rotation axis C1 of the workpiece 100 is quasi-orthogonal, at least one of the plurality of helical gears 120 can be formed.

[0143] According to the above structure, when the posture of the hobbing assembly 200 is controlled such that the hobbing rotation axis C2 and the workpiece rotation axis C1 are quasi-orthogonal, the lead angle of the first tool 231 is set to form at least one of a plurality of helical gears 120. Therefore, by moving the hobbing assembly 200 parallel to or quasi-parallel to the workpiece rotation axis C1, at least one of these movements can be performed, and a plurality of helical gears 120 can be formed on the circumferential surface of the workpiece 100.

[0144] Furthermore, when viewing the hobbing assembly 200 from the direction HD of the hobbing axis, the number of second cutting tools 241 in the circumferential direction of the second hobbing portion 240 is an integer multiple of the number of first cutting tools 231 in the circumferential direction of the first hobbing portion 230. Moreover, the phase of the second cutting tools 241 is different from the phase of the first cutting tools 231. Therefore, when grinding the first hobbing portion 230 using the first hobbing grinding wheel 251, the first hobbing grinding wheel 251 is less likely to interfere with the second hobbing portion 240.

[0145] (4) The hobbing shaft 210 includes an intermediate non-hobbing portion 213, which is disposed between the first hobbing portion 230 and the second hobbing portion 240 in the hobbing shaft direction HD. The first hobbing portion 230 has a first hobbing minimum diameter portion 230D and a first hobbing inner end portion 230B located on the side of the intermediate non-hobbing portion 213 in the hobbing shaft direction HD. The first hobbing minimum diameter portion 230D has a first hobbing minimum radius R12, which is the minimum radius of the first hobbing portion 230. The second hobbing portion 240 has a second hobbing minimum diameter portion 240D and a second hobbing innermost end portion 240B located on the side of the middle non-hobbing portion 213 in the hobbing axis direction HD. The second hobbing minimum diameter portion 240D has a second hobbing minimum radius R22, which is the minimum radius of the second hobbing portion 240 and is greater than the first hobbing minimum radius R12. When the first hobbing grinding wheel 251, used for grinding the first hobbing portion 230, is in a predetermined position, the length of the line segment connecting the minimum diameter 230D of the first hobbing tooth (the innermost end 230B of the first hobbing tooth) and the first grinding wheel rotation axis C4 of the first hobbing grinding wheel 251, i.e., the first reference line LS1, on the reference section, is shorter than the length of the line segment connecting the minimum diameter 240D of the second hobbing tooth (the innermost end 240B of the second hobbing tooth) and the first grinding wheel rotation axis C4, i.e., the second reference line LS2, on the reference section. The predetermined position is the position where the grinding of the first hobbing portion 230 begins or ends with the first hobbing grinding wheel 251, and is the position where the distance from the first grinding wheel rotation axis C4 to the innermost end 240B of the second hobbing tooth is shortest on the reference section.

[0146] According to the above structure, when the first hobbing grinding wheel 251 is in a specified position, the first hobbing grinding wheel 251 can avoid interfering with the innermost end 240B of the second hobbing tooth.

[0147] (5) The gear processing apparatus 1 includes: a gear hobbing assembly 200; a gear hobbing holding part 20 for holding the gear hobbing assembly 200 so as to be rotatable; a workpiece holding part 30 for holding the workpiece 100 so as to be rotatable; and a control part 300 for controlling the movement of the gear hobbing assembly 200 by at least one of parallel movement control and quasi-parallel movement control of the gear hobbing assembly 200 relative to the workpiece rotation axis C1.

[0148] According to the above structure, the control unit 300 can form a plurality of helical gears 120 on the circumferential surface of the workpiece 100 by means of at least one parallel movement control and quasi-parallel movement control.

[0149] (Modified Example)

[0150] The description of the embodiments is an example of the possible methods that can be adopted according to the gear machining method, gear hobbing assembly 200, and gear machining apparatus 1 of this utility model, and is not intended to limit the methods. The gear machining method, gear hobbing assembly 200, and gear machining apparatus 1 of this utility model can be adopted in other ways different from those illustrated in the embodiments, as shown in the following variations. The embodiments and the following variations can be combined with each other within a technically compatible scope.

[0151] Multiple hobbing sections 220 can also be formed separately from the hobbing shaft 210 and mounted on the hobbing shaft 210 in an integral rotating manner.

[0152] The lead angle of the second tool 241 can also be set such that, when the posture of the hobbing assembly 200 is controlled such that the hobbing rotation axis C2 and the workpiece rotation axis C1 are quasi-orthogonal, a second helical gear 122 can be formed. In this modified example, the lead angle of the second tool 241 is, for example, 10° or more and 45° or less. The lead angle of the second tool 241 is, for example, 15°. The radius of the reference circle that serves as the reference for the lead angle of the second tool 241 is called the second lead angle reference radius. The second lead angle reference radius is, in the radial direction of the second hobbing section 240, the distance from the rotation axis of the second hobbing section 240 to the bottom of the second tool 241. The second lead angle reference radius can also be longer than the distance from the rotation axis of the second hobbing section 240 to the bottom of the second hobbing section 241 in the radial direction, and shorter than the distance from the rotation axis of the second hobbing section 240 to the tip of the second hobbing section 241. Alternatively, the second lead angle reference radius can be greater than the distance from the rotation axis of the second hobbing section 240 to the tip of the second hobbing section 241 in the radial direction.

[0153] When the lead angle of the second cutting tool 241 is set as in the modified example described above, the second axis posture control process can also be a process of controlling the posture of the hobbing assembly 200 so that the relationship between the workpiece rotation axis C1 of the workpiece 100 and the hobbing rotation axis C2 of the hobbing assembly 200 is quasi-orthogonal. In this case, the second gear forming process can also be a process of forming the second helical gear 122 on the workpiece 100 by using the second hobbing part 240 to make at least one of the hobbing assembly 200, which is in a quasi-orthogonal relationship with the workpiece 100, move parallel to the workpiece rotation axis C1 and move quasi-parallel to the workpiece.

[0154] • The input process can also be performed by the control unit 300. In this case, the control unit 300 reads the necessary information from multiple data sources during the input process and transfers it to the calculation process.

[0155] • A machining portion 110, different from the small-diameter machining portion 111 and the large-diameter machining portion 112, may also be provided on the workpiece 100. When three or more machining portions 110 are provided on the workpiece 100, they are arranged at intervals along the direction of the workpiece rotation axis C1. The machining portion 110, different from the small-diameter machining portion 111 and the large-diameter machining portion 112, is referred to as an additional machining portion. An additional helical gear is provided on the additional machining portion. When the diameter of the additional machining portion is less than or equal to the diameter of the large-diameter machining portion 112, an additional helical gear is formed on the additional machining portion by at least one of parallel and quasi-parallel movement of the hobbing assembly 200, which is in a quasi-orthogonal relationship with the workpiece 100, relative to the workpiece rotation axis C1, using an additional hobbing portion different from the first hobbing portion 230 or the first hobbing portion 230.

[0156] Explanation of reference numerals in the attached figures

[0157] C1: Workpiece rotation axis

[0158] C2: Hobbing rotation axis

[0159] C4: Rotation axis of the first grinding wheel

[0160] HD: Hobbing shaft direction

[0161] LS1: First baseline

[0162] LS2: Second baseline

[0163] R12: Minimum radius of the first hobbing tooth

[0164] R22: Minimum radius of the second hobbing tooth

[0165] Z: Up / Down direction

[0166] 1: Gear machining equipment

[0167] 20: Gear hobbing retainer

[0168] 30: Workpiece holding part

[0169] 100: Workpiece

[0170] 120: Helical gear

[0171] 121: First helical gear

[0172] 122: Second helical gear

[0173] 200: Gear hobbing assembly

[0174] 210: Gear hobbing shaft

[0175] 213: Intermediate non-hobbed section

[0176] 230: First hobbing section

[0177] 230B: The innermost end of the first hobbing gear

[0178] 230D: Minimum diameter of the first hobbing gear

[0179] 231: First cutting tool

[0180] 240: Second hobbing section

[0181] 240B: The innermost end of the second hob

[0182] 240D: Minimum diameter of the second hobbing gear

[0183] 241: Second cutting tool

[0184] 251: First hobbing grinding wheel

[0185] 300: Control Department

Claims

1. A gear processing apparatus for forming multiple helical gears on a workpiece. The gear processing device includes: A gear hobbing assembly includes a gear hobbing shaft and a plurality of gear hobbing portions, the gear hobbing shaft having a gear hobbing rotation axis, and the plurality of gear hobbing portions being disposed on the gear hobbing shaft at intervals from each other; The gear hobbing retainer holds the gear hobbing assembly so that it can rotate; A workpiece holding part has a workpiece rotation axis and holds the workpiece so that it can rotate; and The control unit controls the posture of the gear hobbing assembly so that the relationship between the workpiece rotation axis and the gear hobbing rotation axis is quasi-orthogonal, and controls the movement of the gear hobbing assembly by at least one of parallel movement control and quasi-parallel movement control of the gear hobbing assembly relative to the workpiece rotation axis.

2. The gear processing apparatus according to claim 1, wherein, The plurality of helical gears include: The first helical gear has a first pitch circle diameter; and The second helical gear is positioned above or below the first helical gear in the vertical direction, and has a second segment circle diameter greater than or equal to the first segment circle diameter. The plurality of hobbing portions include a first hobbing portion for forming the first helical gear and a second hobbing portion for forming the second helical gear. The control unit controls the hobbing assembly by at least one of parallel and quasi-parallel movement relative to the workpiece's rotation axis, which is in a quasi-orthogonal relationship with the workpiece, so that the first hobbing part forms the first helical gear on the workpiece.

3. A gear hobbing assembly for forming multiple helical gears on a workpiece, The gear hobbing assembly includes: A gear hobbing shaft, having a gear hobbing rotation axis; A first hobbing portion disposed on the hobbing shaft and used to form a first helical gear on the workpiece; and A second hobbing portion is disposed at a distance from the first hobbing portion on the hobbing shaft and is used to form a second helical gear on the workpiece. When the hobbing assembly is viewed from the hobbing axis direction, which is the direction along the rotation axis of the hobbing gear, the number of the second cutters in the circumferential direction of the second hobbing part is an integer multiple of the number of the first cutters in the circumferential direction of the first hobbing part. The phase of the second tool is different from the phase of the first tool. The lead angle of the first tool is set such that at least one of the plurality of helical gears can be formed when the posture of the hobbing assembly is controlled such that the hobbing rotation axis of the hobbing shaft and the workpiece rotation axis of the workpiece are quasi-orthogonal.

4. The gear hobbing assembly according to claim 3, wherein, The gear hobbing shaft includes an intermediate non-hobbing portion, which is disposed between the first hobbing portion and the second hobbing portion in the direction of the gear hobbing shaft. The first hobbing portion has a first hobbing minimum diameter portion and an innermost end portion of the first hobbing tooth located on the side of the intermediate non-hobbing portion in the hobbing axis direction. The first hobbing minimum diameter portion has a first hobbing minimum radius, which is the minimum radius of the first hobbing portion. The second hobbing portion has a second hobbing minimum diameter portion and an innermost end portion of the second hobbing tooth located on the side of the intermediate non-hobbing portion in the hobbing axis direction. The second hobbing minimum diameter portion has a second hobbing minimum radius, which is the minimum radius of the second hobbing portion and is greater than the minimum radius of the first hobbing tooth. When the first hobbing grinding wheel used for grinding the first hobbing portion is in a specified position, the length of the first reference line, which connects the minimum diameter of the first hobbing tooth at the innermost end of the first hobbing tooth and the rotation axis of the first grinding wheel on the reference section, is shorter than the length of the second reference line, which connects the minimum diameter of the second hobbing tooth at the innermost end of the second hobbing tooth and the rotation axis of the first grinding wheel on the reference section. The specified position is the position where the grinding of the first hobbing gear begins or ends, and it is the position where the distance from the rotation axis of the first grinding wheel to the innermost end of the second hobbing gear is the shortest on the reference section.

5. A gear processing apparatus, comprising: The gear hobbing assembly according to any one of claims 3 and 4; The gear hobbing retainer holds the gear hobbing assembly so that it can rotate; The workpiece holding part holds the workpiece so that it can rotate; and The control unit controls the movement of the gear hobbing assembly by at least one of parallel movement control and quasi-parallel movement control, which involve parallel movement of the gear hobbing assembly relative to the rotation axis of the workpiece.

6. A gear hobbing assembly for forming helical gears on a workpiece, The gear hobbing assembly includes: A gear hobbing shaft having a gear hobbing rotation axis; and The first hobbing portion, disposed on the hobbing shaft and used to form the first helical gear on the workpiece, is a first hobbing part. The lead angle of the first cutter of the first hobbing section is set such that, when the posture of the hobbing assembly is controlled such that the hobbing rotation axis of the hobbing shaft is quasi-orthogonal to the workpiece rotation axis, the first helical gear can be formed by making at least one of the hobbing assembly move parallel and quasi-parallel relative to the workpiece rotation axis.

7. The gear hobbing assembly according to claim 6, wherein, It also includes a second hobbing portion, which is disposed on the hobbing shaft at a distance from the first hobbing portion and is used to form a second helical gear on the workpiece. When the hobbing assembly is viewed from the hobbing axis direction, which is the direction along the rotation axis of the hobbing gear, the number of the second cutter of the second hobbing part in the circumferential direction is an integer multiple of the number of the first cutter of the first hobbing part in the circumferential direction.

8. The gear hobbing assembly according to claim 7, wherein, The phase of the second tool is different from the phase of the first tool.

9. The gear hobbing assembly according to claim 8, wherein, The gear hobbing shaft includes an intermediate non-hobbing portion, which is disposed between the first hobbing portion and the second hobbing portion in the direction of the gear hobbing shaft. The first hobbing portion has a first hobbing minimum diameter portion and an innermost end portion of the first hobbing tooth located on the side of the intermediate non-hobbing portion in the hobbing axis direction. The first hobbing minimum diameter portion has a first hobbing minimum radius, which is the minimum radius of the first hobbing portion. The second hobbing portion has a second hobbing minimum diameter portion and an innermost end portion of the second hobbing tooth located on the side of the intermediate non-hobbing portion in the hobbing axis direction. The second hobbing minimum diameter portion has a second hobbing minimum radius, which is the minimum radius of the second hobbing portion and is greater than the minimum radius of the first hobbing tooth. When the first hobbing grinding wheel used for grinding the first hobbing portion is in a specified position, the length of the first reference line, which connects the minimum diameter of the first hobbing tooth at the innermost end of the first hobbing tooth and the rotation axis of the first grinding wheel on the reference section, is shorter than the length of the second reference line, which connects the minimum diameter of the second hobbing tooth at the innermost end of the second hobbing tooth and the rotation axis of the first grinding wheel on the reference section. The specified position is the position where the grinding of the first hobbing gear begins or ends, and it is the position where the distance from the rotation axis of the first grinding wheel to the innermost end of the second hobbing gear is the shortest on the reference section.

10. A gear processing apparatus, comprising: The gear hobbing assembly according to any one of claims 6 to 9; The gear hobbing retainer holds the gear hobbing assembly so that it can rotate; The workpiece holding part holds the workpiece so that it can rotate; and The control unit controls the movement of the gear hobbing assembly by at least one of parallel movement control and quasi-parallel movement control, which involve parallel movement of the gear hobbing assembly relative to the rotation axis of the workpiece.

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