Method for designing gear processing tool and device for supporting designing gear processing tool

Abstract

A method for designing a gear machining tool (T) is provided with: a step (S1) for acquiring a specification, a tool specification, and a target tooth profile direction dressing amount, and temporarily designing a tool blade shape of the gear machining tool on the basis of the gear specification, the tool specification, and the target tooth profile direction dressing amount; a step (S2) for acquiring a linear-direction target dressing amount and determining a correction amount for a machining control element on the basis of the tooth-line-direction target dressing amount; a step (S33) for calculating a first tooth surface shape of the gear on the basis of the correction amount of the machining control element and the temporarily designed tool blade shape; a step (S35) for comparing the first tooth surface shape with a target tooth surface shape and calculating a first target error in the tooth shape direction in the first tooth surface shape; and a step (S38) for formally designing the tool blade shape on the basis of the tooth profile direction target trimming amount and a first target error trimming amount for reducing the first target error.

Description

Technical Field

[0001] The present invention relates to a design method for a gear machining tool and a design assisting device for the gear machining tool. Background Art

[0002] When gears are subjected to load, deformation of the teeth and shaft can deteriorate the meshing state, generating noise. To achieve ideal meshing under load, and to improve quietness, gears need to adjust the tooth profile. Factors that modify the tooth profile include tooth line inclination (also known as "tooth line twist"), crown, offset, pressure angle, and tooth fillet. Tooth line inclination, crown, and offset modify the gear's tooth line direction, while pressure angle and tooth fillet modify the gear's tooth profile direction (from tooth bottom to tooth tip).

[0003] Japanese Patent Application Publication No. 2021-11011 (Patent Document 1) describes a technique for applying additional motion to a gear machining tool to change the trimming element in the gear tooth trace direction. This technique is expected to improve the accuracy of the gear tooth trace direction.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2021-11011

[0005] However, according to the above-mentioned technology, when the gear machining tool is given additional motion to machine the gear, the accuracy of the gear tooth trace direction is improved, but there is a problem that the shape of the gear tooth profile direction has errors. Summary of the Invention

[0006] The present invention has been made in view of such problems and provides a design method for a gear machining tool and a design support device for a gear machining tool, which can correct errors related to the tooth trace direction and tooth profile direction of a gear.

[0007] A technical solution of the present invention provides a method for designing a gear processing tool, in which an axis in the gear processing tool is parallel to the central axis of the gear processing tool and has a predetermined axis crossing angle with respect to the central axis of the workpiece, while the gear processing tool and the workpiece are rotated synchronously, the workpiece and the gear processing tool are moved relative to each other, thereby processing the teeth of the gear on the workpiece, wherein the method for designing the gear processing tool comprises: obtaining the specifications of the gear, namely the gear specifications, obtaining the specifications of the gear processing tool, namely the tool specifications, obtaining the target value of the tooth profile direction trimming element of the tooth surface shape of the gear, namely the tooth profile direction target trimming amount, and based on the gear specifications, the tool specifications and the tooth profile direction target trimming amount, obtaining the target value of the tooth profile direction trimming element of the tooth surface shape of the gear, obtaining the target value of the tooth profile direction trimming element, namely the tooth profile direction target trimming amount, and processing the gear teeth on the workpiece. The present invention relates to a process for temporarily designing the tool blade shape of the gear processing tool based on the adjustment amount; a process for obtaining the target value of the tooth line direction adjustment element of the tooth surface shape, that is, the tooth line direction target adjustment amount, and determining the correction amount of the processing control element in the processing action based on the tooth line direction target adjustment amount; a process for calculating the first tooth surface shape of the gear based on the correction amount of the processing control element and the temporarily designed tool blade shape; a process for comparing the calculated first tooth surface shape with the target tooth surface shape included in the gear specification, and calculating the first target error in the tooth profile direction in the first tooth surface shape; and a process for formally designing the tool blade shape based on the tooth profile direction target adjustment amount and the first target error adjustment amount for reducing the first target error.

[0008] In addition, another technical solution of the present invention provides a design assistance device for a gear processing tool, in which an axis parallel to the central axis of the gear processing tool has a predetermined axis crossing angle with respect to the central axis of the workpiece, while the gear processing tool and the workpiece are rotated synchronously, the workpiece and the gear processing tool are moved relative to each other, thereby processing the teeth of the gear on the workpiece, wherein the design assistance device for the gear processing tool comprises: a gear specification acquisition unit for acquiring the specifications of the gear, namely, the gear specifications; a tool specification acquisition unit for acquiring the specifications of the gear processing tool, namely, the tool specifications; a tooth profile direction target trimming amount acquisition unit for acquiring the target value of the tooth profile direction trimming element of the tooth surface shape of the gear, namely, the tooth profile direction target trimming amount; a temporary design unit, based on the gear specifications, the tool specifications and the a tooth profile direction target trimming amount, temporarily designs the tool blade shape of the gear processing tool; a tooth line direction target trimming amount acquisition unit, obtains the target value of the tooth line direction trimming element of the tooth surface shape, namely the tooth line direction target trimming amount; a correction amount determination unit, determines the correction amount of the processing control element in the processing action based on the tooth line direction target trimming amount; a first tooth surface shape calculation unit, calculates the first tooth surface shape of the gear based on the correction amount of the processing control element and the temporarily designed tool blade shape; a first target error calculation unit, compares the calculated first tooth surface shape with the target tooth surface shape included in the gear specification, and calculates the first target error in the tooth profile direction in the tooth surface shape; and a formal design unit, formally designs the tool blade shape based on the tooth profile direction target trimming amount and the first target error trimming amount for reducing the first target error.

[0009] According to one and other aspects of the present invention, a first target error is generated by correcting machining control elements during machining based on a target tooth trace direction trimming amount. The tool edge shape of the gear machining tool T is then formally designed based on the first target error trimming amount to reduce the first target error. Consequently, even when the machining control elements are corrected based on the target tooth trace direction trimming amount, errors in the gear tooth surface shape in the tooth profile direction can be suppressed.

[0010] In addition, the reference numerals in parentheses described in the claims indicate the correspondence relationship with specific elements described in the embodiments described later, and do not limit the technical scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a perspective view showing the processing device in Embodiment 1.

[0012] Figure 2 This diagram shows the workpiece and the gear processing tool during gear skiving, with the axis crossing angle set as viewed in the radial direction of the gear processing tool.

[0013] Figure 3 Observed in the direction of the center axis of the gear processing tool Figure 2 Picture.

[0014] Figure 4 These are diagrams for explaining the operation of gear skiving, and are diagrams viewed in the radial direction of the gear processing tool.

[0015] Figure 5 Observed in the direction of the center axis of the processing tool Figure 4 Picture.

[0016] Figure 6 This diagram shows the workpiece and the gear processing tool during gear skiving, with the set runout angle viewed in the radial direction of the gear processing tool.

[0017] Figure 7 It is a diagram showing the amount of convexity correction of the correction element.

[0018] Figure 8 This is a diagram showing the offset adjustment amount of the correction element.

[0019] Figure 9 It is a diagram showing the amount of adjustment of the tooth trace inclination of the correction element.

[0020] Figure 10 It is a diagram showing the adjustment amount of the pressure angle of the correction element.

[0021] Figure 11 This is a diagram showing the amount of rounding of the tooth profile of the correction element.

[0022] Figure 12 This is a diagram showing a motion in which the center-to-center distance between the center axis of the gear machining tool and the center axis of the workpiece is parabolically changed relative to the position of the tooth width.

[0023] Figure 13 This diagram shows a motion in which the position of the axis intersection angle between the center axis of the gear machining tool and the center axis of the workpiece relative to the tooth width is linearly changed.

[0024] Figure 14 This is a diagram showing a motion in which the rotation angle of the workpiece relative to the rotation angle of the gear machining tool is linearly changed relative to the position of the tooth width.

[0025] Figure 15 Graphs showing correlations between the Y-axis variation and the crowning amount, the Y-axis variation and the offset variation, and the Y-axis variation and the tooth trace inclination variation.

[0026] Figure 16Graphs showing correlations between the amount of change in the B-axis and the amount of crowning, correlations between the amount of change in the B-axis and the amount of offset correction, and correlations between the amount of change in the B-axis and the amount of tooth trace inclination correction.

[0027] Figure 17 Graphs showing correlations between the amount of change in the Cw axis and the amount of crowning, correlations between the amount of change in the Cw axis and the amount of offset modification, and correlations between the amount of change in the Cw axis and the amount of tooth trace inclination modification.

[0028] Figure 18 The graph shows the correlation between the X and Y axis changes and the crowning amount, the offset change, and the tooth line inclination change.

[0029] Figure 19 This is a diagram showing the configuration of a design support device according to the first embodiment.

[0030] Figure 20 This is a flowchart showing the operation of the design support device and the main flow of the design method.

[0031] Figure 21 This is a flowchart showing a temporary design process of a tool blade shape.

[0032] Figure 22 : is a flowchart showing the correction amount determination process.

[0033] Figure 23 This is a flowchart showing the formal design process.

[0034] Figure 24 This is a perspective view showing a state in which a first target error is calculated based on a cross section perpendicular to the axis at one location in the center of the gear in the tooth width direction.

[0035] Figure 25 is a flowchart showing the second error calculation process.

[0036] Figure 26 is a flowchart showing the redesign process.

[0037] Figure 27 This is a flowchart showing the correction amount redetermination process.

[0038] Figure 28 This is a perspective view showing a state in which a first target error is calculated based on an axis-orthogonal cross section at any one position in the tooth width direction of the gear in the second embodiment.

[0039] Figure 29 This is a perspective view showing a state in which a first target error is calculated based on axis-orthogonal cross sections at a plurality of locations in the tooth width direction of a gear in the third embodiment.

[0040] Figure 30 This is a perspective view showing a state in which the first target error is calculated based on the entire range in the tooth width direction of the gear in the fourth embodiment.

[0041] Figure 31 This is a perspective view showing a state in which a first target error is calculated based on a partial range in the tooth width direction of a gear in the fifth embodiment. DETAILED DESCRIPTION

[0042] (Implementation 1)

[0043] 1. Structure of gear processing device

[0044] The first embodiment of the present invention relates to a design method and design support device for a gear machining tool (also referred to as a "gear scraper") for use in designing a gear machining tool for machining a workpiece. In this embodiment, the workpiece is supported by a gear machining device, and the gear teeth are formed by the gear machining tool attached to the gear machining device.

[0045] Reference Figure 1 The structure of the gear machining apparatus will be described. The gear machining apparatus 1 of this embodiment machines gear teeth on the workpiece W by rotating the gear machining tool T and the workpiece W in sync while moving the workpiece W relative to the gear machining tool T, with an axis parallel to the center axis RT of the gear machining tool T at a predetermined axis intersection angle α relative to the center axis RW of the workpiece W.

[0046] like Figure 1 As shown, the gear processing device 10 is, for example, a five-axis machining center having three forward axes and two rotation axes as a driving axis for changing the relative position and posture of the workpiece W and the gear processing tool T. In this embodiment, the gear processing device 10 has three orthogonal axes (X axis, Y axis, Z axis) as forward axes and a B axis and a Cw axis as rotation axes. In this embodiment, the B axis is a rotation axis around the center axis RB of the rotary table 14 parallel to the Y axis, and the Cw axis is a rotation axis around the center axis RW of the workpiece W. In addition, the gear processing device 10 has a Ct axis, which is a rotation axis around the center axis RT of the gear processing tool T. If the Ct axis is included, it becomes a six-axis machining center.

[0047] The gear machining device 10 includes a tool spindle 11 that supports a gear machining tool T and is rotatable about the Ct axis and movable in both the Y and Z axes. Furthermore, the gear machining device 10 includes a workpiece spindle 12 that supports a workpiece W and is rotatable about the Cw axis, rotatable about the B axis, and movable in the X axis. This embodiment describes the machining of gear teeth on the workpiece W through gear skiving. The configuration is not limited to the above; the tool spindle 11 and the workpiece spindle 12 may be any configuration capable of relative movement.

[0048] 2. Gear skiving

[0049] Reference Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 as well as Figure 6 The gear skiving process is explained. Figure 2 as well as Figure 3 As shown, during gear skiving, the center axis RT of the gear machining tool T forms an axis intersection angle α with respect to an axis parallel to the center axis RW of the workpiece W. Furthermore, when viewed from the X-axis direction, the center axis RT of the gear machining tool T is parallel to the center axis RW of the workpiece W. Furthermore, the center-to-center distance between the center axis RT of the gear machining tool T and the center axis RW of the workpiece W is denoted by D.

[0050] Moreover, if Figure 4 as well as Figure 5 As shown, a method is described in which the gear machining tool T is conveyed relative to the workpiece W in the direction of the center axis RW of the workpiece W while synchronizing the rotation of the workpiece W about the center axis RW of the workpiece W with the rotation of the gear machining tool T about the center axis RT of the gear machining tool T, thereby machining gear teeth on the workpiece W. During gear skiving, each tooth groove of the workpiece W is machined once by the gear machining tool T during one rotation of the workpiece W.

[0051] exist Figure 6 y represents the deviation angle γ. The deviation angle γ is the angle at which the machining point of the gear machining tool T and the workpiece W are offset in the circumferential direction of the workpiece W. The reference position at which the deviation angle γ is zero is the position of the gear machining tool T corresponding to the machining point where the center axis RT of the gear machining tool T is parallel to the center axis RW of the workpiece W and when viewed from a direction perpendicular to the center axis RW of the workpiece W (in this embodiment, the X-axis direction), when the machining point is varied in the circumferential direction of the workpiece W.

[0052] 3. Tooth surface finishing factors

[0053] Reference Figures 7 to 11 The tooth surface modification elements when modifying the gear tooth surface shape are explained. Figures 7 to 11 As shown, among the modification elements of the shape of the tooth surface Gf of the gear tooth G, there are modification elements in the tooth trace direction and modification elements in the tooth profile direction. As the modification elements in the tooth trace direction, there are convex surfaces ( Figure 7 ), bias( Figure 8 ), tooth line tilt ( Figure 9 As a modification factor in the tooth profile direction, there is a pressure angle ( Figure 10 ) and tooth fillet ( Figure 11 Here, convex means that the center of the tooth width in the tooth trace direction is higher than the two ends. Offset means that the pressure angle is continuously changed in the tooth trace direction, giving the tooth surface a twist.

[0054] like Figure 7 As shown, the crowning amount Mc is represented by the distance of the portion where the measurement diameter passes through the center position (in this embodiment, the center position of the tooth width) of the evaluation range Dc in the tooth trace direction on the tooth surface Gf of the tooth G. Figure 8 As shown, the offset trimming amount Mb is represented by the difference between the pressure angles Mp1 and Mp2 at both ends of the evaluation range Db in the tooth trace direction on the tooth surface Gf of the tooth G (in this embodiment, positions Db / 2 from the center of the tooth width to both sides).

[0055] like Figure 9 As shown, the tooth trace inclination adjustment amount Mh is represented by the difference in height in the tooth trace direction of the portion where the measured diameter passes through at both end positions of the tooth trace direction evaluation range Dh on the tooth surface Gf of the tooth G (in this embodiment, the position of one end surface of the tooth and the center position of the tooth width).

[0056] like Figure 10 As shown, the pressure angle adjustment amount Mp is represented by the tilt error in the tooth height direction at the center position (in this embodiment, the center position of the tooth width) of the evaluation range Dp in the tooth trace direction on the tooth surface Gf of the tooth G. Figure 11 As shown, the tooth profile fillet correction amount Mr is represented by the convex amount of the tooth profile error at the center position of the evaluation range Dr in the tooth trace direction on the tooth surface Gf of the tooth G (in this embodiment, the center position of the tooth width).

[0057] 4. Basic tooth surface finishing methods

[0058] The pressure angle and tooth profile fillet in the tooth surface shape trimming elements are trimming in the tooth profile direction, which becomes a transfer of the tool blade shape. That is, the blade shape of the gear processing tool T can be used for trimming. In addition, tool specifications such as the number of blades, displacement coefficient, torsion angle, blade angle, and rake angle can also be used for additional correction. On the other hand, the convex surface, offset, and tooth line inclination in the tooth surface shape trimming elements are trimming in the tooth line direction, which becomes a transfer of the motion trajectory of the gear processing device 10. That is, the processing control elements of the gear processing device 10, namely the Cw axis, B axis, X axis, and Y axis, can be used for trimming. In addition, the pressure angle and tooth profile fillet can also be trimmed using the processing control elements of the gear processing device 10, but in this method, they are trimmed based on the tool blade shape (specifications) of the gear processing tool T.

[0059] Specifically, if Figure 12 As shown, by making the center distance D between the center axis RT of the gear machining tool T and the center axis RW of the workpiece W ( Figure 3 as well as Figure 5 As shown in FIG, the position of the tooth width relative to the tooth width changes and moves in a parabolic manner as it advances in the tooth width direction, thereby forming a convex surface. Therefore, the convex surface can be trimmed by controlling the Y-axis movement in the gear processing device 10.

[0060] like Figure 13 As shown, an offset can be created by linearly changing the position of the intersection angle α formed by the center axis RT of the gear machining tool T and the center axis RW of the workpiece W relative to the tooth width as the gear machining tool T advances in the tooth width direction. Therefore, the offset can be adjusted by controlling the rotation of the gear machining tool T about an axis parallel to the Y-axis. However, in the gear machining device 10, the gear machining tool T does not rotate, so adjustment can be achieved by controlling the movement of the B-axis, the rotation axis of the workpiece W (the workpiece rotation angle (intersection angle α)).

[0061] In addition, although not shown in the figure, even if the deviation angle γ when the processing point of the gear processing tool T and the workpiece W is offset in the circumferential direction of the workpiece W changes as it advances in the tooth width direction, an offset can be formed, so that in the gear processing device 10, adjustment can be performed by controlling the movement of the X-axis and the Y-axis.

[0062] like Figure 14 As shown, the tooth trace inclination can be formed by linearly changing the position of the workpiece W relative to the tooth width as the workpiece W moves in the tooth width direction relative to the rotation angle of the gear machining tool T. Therefore, the tooth trace inclination can be corrected by controlling the movement of the Cw axis in the gear machining device 10. Figures 12 to 14The horizontal axis represents the position of the tooth width of the processing point of the gear processing tool T and the workpiece W, that is, from the position of the right tooth surface on one end face side of the tooth (processing start position) to the position of the right tooth surface on the other end face side of the tooth (processing end position).

[0063] 5. Correlation between finishing factors and processing control factors

[0064] Next, refer to Figures 15 to 18 The correlation between each dressing element and each processing control element is explained. Here, the correlation between each dressing element and each processing control element varies depending on the specifications of the gear processing tool T. Moreover, the tool specifications of the gear processing tool T are determined based on the specifications of the gear processed on the workpiece W. Therefore, Figures 15 to 18 Each correlation shown represents a correlation for a specific gear machining tool T. Different gear machining tools T will display different correlations. Examples of trimming elements include crowning, offset, and tooth trace tilt, which are trimming elements in the tooth trace direction. Examples of machining control elements include the Y-axis, B-axis, Cw-axis, and runout angle γ (synchronized with the X and Y axes).

[0065] Figure 15 These represent the correlations between the Y-axis variation ΔY and the crown adjustment amount Mc, the Y-axis variation ΔY and the offset adjustment amount Mb, and the Y-axis variation ΔY and the tooth trace inclination adjustment amount Mh. When performing a gear machining simulation with only the Y-axis varied from the baseline machining control element, these correlations are calculated based on the error between the gear tooth surface shape obtained from the gear machining simulation and the baseline tooth surface shape.

[0066] For example, for each correlation, the correlation between the trimming factor and the machining control factor is calculated using, for example, a quadratic function based on the gear tooth surface shape obtained through gear machining simulation. Specifically, the error between the gear tooth surface shape obtained through gear machining simulation and the reference tooth surface shape, i.e., the tooth surface of an involute screw, is calculated, and the correlation between the calculated error and the change in the machining control factor (Y-axis) is calculated.

[0067] Specifically, a gear machining simulation is first performed to gradually change the Y-axis, a machining control factor, to calculate multiple tooth profiles. This process is repeated sequentially to calculate the overall tooth profile shape. Furthermore, correlation is calculated for each tooth profile shape by calculating the respective adjustment amounts Mc, Mb, and Mh for the tooth trace direction adjustment factors, namely crown, offset, and tooth trace inclination. The calculated adjustment amounts Mc, Mb, and Mh are then plotted against the Y-axis change ΔY, a machining control factor.

[0068] In addition, the Y-axis variation ΔY includes values ​​obtained by changing from the reference value in the positive direction multiple times and values ​​obtained by changing from the reference value in the negative direction multiple times. Figure 15 As shown in FIG, if the Y axis is changed, the convex surface can be greatly changed. However, if the Y axis is changed, the offset and the tooth line inclination will also change.

[0069] Gear machining simulation is described in, for example, Japanese Patent Application Laid-Open No. 2017-144502. Reference machining control elements are machining control elements used to machine a gear without crowning, offset, trimmed tooth line inclination, pressure angle, or tooth fillet. Furthermore, trimmed tooth line inclination refers to the tooth line inclination relative to the reference tooth line inclination, which is the standard for the gear.

[0070] Figure 16 This chart shows the correlation between the B-axis variation ΔB and the crowning adjustment amount Mc, the offset adjustment amount Mb, and the tooth trace inclination adjustment amount Mh. Each correlation is calculated based on the error between the gear tooth surface shape obtained from the gear machining simulation and the reference tooth surface shape, when performing a gear machining simulation with only the B-axis changed from the reference machining control elements. The B-axis variation ΔB is controlled by the workpiece rotation angle (axis intersection angle α).

[0071] The graph that corresponds the crown, offset, and tooth line tilt adjustment amounts Mc, Mb, and Mh to the B-axis variation ΔB, which is a machining control element, is essentially created in the same manner as the Y-axis. The B-axis variation ΔB includes values ​​obtained by changing from the reference value in the positive direction multiple times and values ​​obtained by changing from the reference value in the negative direction multiple times. Figure 16 As shown in FIG, if the B axis is changed, the offset can be greatly changed. However, if the B axis is changed, the crown and the tooth trace inclination will also change.

[0072] Figure 17 This chart shows the correlation between the Cw-axis variation ΔCw and the crowning adjustment amount Mc, the offset adjustment amount Mb, and the tooth trace inclination adjustment amount. These correlations are calculated based on the error between the gear tooth surface shape obtained from the gear machining simulation and the reference tooth surface shape, when performing a gear machining simulation with only the Cw-axis varied from the reference machining control element. The Cw-axis variation ΔCw is controlled by the workpiece rotation angle β.

[0073] The graph that corresponds to the crown, offset, and tooth line tilt adjustment amounts Mc, Mb, and Mh and the Cw axis change ΔCw, which is a machining control element, is essentially created in the same way as the Y axis. The Cw axis change ΔCw includes values ​​obtained by changing from the reference value in the positive direction multiple times and values ​​obtained by changing from the reference value in the negative direction multiple times. Figure 17 As shown in FIG, if the Cw axis is changed, the tooth trace inclination can be greatly changed. In addition, when the Cw axis is changed, the crown and the offset are almost unchanged.

[0074] Figure 18 The correlation between the change in the deviation angle γ and various dressing factors is shown. Here, the deviation angle γ refers to the angle at which the machining point of the gear machining tool T and the workpiece W is offset in the circumferential direction of the workpiece W. Therefore, the deviation angle γ can be expressed by synchronizing the X and Y axes. In other words, the change in the deviation angle γ can be expressed as the changes ΔX and ΔY based on the synchronized X and Y axes. Hereinafter, the change in the deviation angle γ is expressed as ΔX and ΔY.

[0075] Right now, Figure 18 The following table shows the correlation between the change in the deviation angle γ, ΔX, Y, and the crowning adjustment amount Mc; the correlation between the change in the deviation angle γ, ΔX, Y, and the offset adjustment amount Mb; and the correlation between the change in the deviation angle γ, ΔX, Y, and the tooth trace inclination adjustment amount Mh. These correlations are calculated based on the error between the gear tooth surface shape obtained from the gear machining simulation and the reference tooth surface shape, when performing a gear machining simulation with only the deviation angle γ changed from the reference machining control element.

[0076] The graphs corresponding to the respective trimming amounts Mc, Mb, Mh of the crown, offset, and tooth line inclination and the variation amounts ΔX, ΔY of the deviation angle γ, which are the machining control elements, are prepared in substantially the same manner as the Y-axis graphs described above. Figure 18 As shown in FIG, if the offset angle γ is changed, the offset can be greatly changed. However, if the offset angle γ is changed, the crown and the tooth trace inclination also change.

[0077] As described above, each trimming factor and each process control factor influence each other. Therefore, even when adjusting one trimming factor, other trimming factors are also affected, necessitating adjustment of those other trimming factors. Furthermore, while the process control factors (Y-axis, B-axis, Cw-axis, and deviation angle γ) are varied individually in the above description, multiple factors can also be varied synchronously based on predetermined synchronization conditions. In this case, correlations between the process control factors and the trimming factors can also be determined.

[0078] 6. Calculation method of error from reference tooth surface

[0079] As described above, each correlation is calculated based on the error between the gear tooth surface shape and the reference tooth surface shape when each machining control factor is varied. Furthermore, the reference tooth surface shape is, for example, an involute tooth surface. For example, Japanese Patent Application Laid-Open No. 2021-11011 describes a method for calculating the error from the reference tooth surface.

[0080] 7. Design of the structure of the auxiliary device 20

[0081] Reference Figure 19 The structure of the design support device 20 will be described. The design support device 20 is a device that assists in machining gear teeth by modifying the tooth surface shape. The design support device 20 can be implemented as an embedded system (microcomputer) such as a PLC (Programmable Logic Controller) or a CNC (Computerized Numerical Control) device, or as a personal computer or server.

[0082] like Figure 19 As shown, the design support device 20 includes a storage device 21 that stores gear specifications (gear specifications), tool specifications (gear machining tool T specifications), target values ​​of gear tooth profile direction modification elements (tooth profile direction target modification amounts), and target values ​​of tooth trace direction modification elements (tooth trace direction target modification amounts). The design support device 20 includes a gear specification acquisition unit 22 that acquires the gear specifications from the storage device 21, a tool specification acquisition unit 23 that acquires tool specifications from the storage device 21, a tooth profile direction target modification amount acquisition unit 24 that acquires the tooth profile direction target modification amount from the storage device 21, and a tooth trace direction target modification amount acquisition unit 25 that acquires the tooth trace direction target modification amount from the storage device 21. The tooth profile direction modification elements include at least one of a pressure angle and a tooth profile fillet, and the tooth trace direction modification elements include at least one of a crown, an offset, and a tooth trace inclination.

[0083] The provisional design unit 26 acquires the gear specifications from the gear specification acquisition unit 22, the tool specifications from the tool specification acquisition unit 23, and the target tooth profile direction trimming amount from the target tooth profile direction trimming amount acquisition unit 24. The provisional design unit 26 provisionally designs the tool edge shape of the gear machining tool T based on the gear specifications, tool specifications, and the target tooth profile direction trimming amount.

[0084] The correction amount determination unit 27 acquires the target tooth trace direction trimming amount from the tooth trace direction trimming amount acquisition unit 25. Based on the target tooth trace direction trimming amount acquisition unit 25, the correction amount determination unit 27 determines the correction amount for the machining control element during the machining operation. The machining control element includes at least one of the axis intersection angle α, the deviation angle γ indicating the position of the gear machining tool T in the circumferential direction of the workpiece, the center-to-center distance D between the center axis of the workpiece and the center axis of the gear machining tool T, and the relative rotational speed between the workpiece and the gear machining tool T.

[0085] The first tooth surface shape calculation unit 28 receives the provisionally designed tool blade shape of the gear machining tool T from the provisional design unit 26 and receives the correction amount of the machining control element from the correction amount determination unit 27. The first tooth surface shape calculation unit 28 calculates the first tooth surface shape of the gear based on the provisionally designed tool blade shape and the correction amount of the machining control element.

[0086] The first target error calculation unit 29 obtains the first tooth surface shape from the first tooth surface shape calculation unit 28 and obtains the target tooth surface shape included in the gear specifications from the gear specification acquisition unit 22. The first target error calculation unit 29 compares the calculated first tooth surface shape with the target tooth surface shape and calculates a first target error in the tooth surface shape in the tooth profile direction.

[0087] The formal design unit 30 obtains the first target error from the first target error calculation unit 29 and obtains the target tooth profile direction adjustment amount from the target tooth profile direction adjustment amount acquisition unit 24. The formal design unit 30 formally designs the tool edge shape based on the target tooth profile direction adjustment amount and the first target error adjustment amount for reducing the first target error.

[0088] The second tooth surface shape calculation unit 31 obtains the officially designed tool edge shape from the official design unit 30 and obtains the correction amount of the machining control element from the correction amount determination unit 27. The second tooth surface shape calculation unit 31 calculates the second tooth surface shape of the gear based on the correction amount of the machining control element and the officially designed tool edge shape.

[0089] The second target error calculation unit 32 obtains the calculated second tooth surface shape from the second tooth surface shape calculation unit 31 and obtains the target tooth surface shape included in the gear specifications from the gear specification acquisition unit 22. The second tooth surface shape calculation unit 31 compares the calculated second tooth surface shape with the target tooth surface shape and calculates a second target error for the second tooth surface shape.

[0090] The redesign unit 33 acquires the target tooth profile direction trimming amount from the tooth profile direction target trimming amount acquisition unit 24, acquires the target tooth trace direction trimming amount from the tooth trace direction target trimming amount acquisition unit 25, and acquires the second target error from the second target error calculation unit 32. The redesign unit 33 redesigns the tool edge shape based on at least one of the target tooth profile direction trimming amount and the target tooth trace direction trimming amount and the second target error trimming amount for reducing the second target error.

[0091] The correction amount re-determining unit 34 obtains the target tooth profile direction trimming amount from the target tooth profile direction trimming amount acquiring unit 24, obtains the target tooth trace direction trimming amount from the target tooth trace direction trimming amount acquiring unit 25, and obtains the second target error from the second target error calculating unit 32. The correction amount re-determining unit 34 re-determines the correction amount of the machining control element based on at least one of the target tooth profile direction trimming amount and the target tooth trace direction trimming amount and the second target error trimming amount for reducing the second target error.

[0092] However, the design support device of this embodiment may include both the redesign unit 33 and the correction amount redetermination unit 34 , or may include only one of them.

[0093] 8. Operation of the Design Support Device 20 (Design Method)

[0094] (1) Main program

[0095] Next, the operation and design method of the design support device 20 of this embodiment will be described. Figure 20 As shown, when the design support device 20 is activated, a provisional design process for provisionally designing the tool blade shape of the gear machining tool T is executed (S1: provisional design step). Next, a correction amount determination process for determining the correction amount of the machining control element in the gear machining operation is executed (S2: correction amount determination step). Next, a formal design process for formally designing the tool blade shape of the gear machining tool T is executed (S3: formal design step).

[0096] The gear machining tool T determines the tool blade shape by performing a formal design process, and a workpiece is machined using the machining tool T to form a gear. For the gear, the following second target error calculation process (S4: second target error calculation process) is performed to compare the second tooth surface shape formed on the gear with the target tooth surface shape included in the gear specifications, and calculate the second target error of the second tooth surface shape. Next, based on the second target error, a redesign process (S5: redesign process) is performed to redesign the tool blade shape. In addition, based on the second target error, a correction amount redetermination process (S6: correction amount redetermination process) is performed to redetermine the correction amount of the machining control element. However, the order of the redesign process (S5) and the correction amount redetermination process (S6) is not limited. In addition, it is also possible to configure the redesign process (S5) and the correction amount redetermination process (S6) to both be performed, or it is also possible to configure the redesign process (S5) and the correction amount redetermination process (S6) to be performed only one of them.

[0097] (2) Temporary design processing

[0098] like Figure 21 As shown, when the provisional design process is executed, the gear specification acquisition unit 22 acquires the gear specifications from the storage device 21 (S11: gear specification acquisition step). The gear specifications include information related to the shape and material of the teeth of the gear to be machined on the workpiece. Next, the tool specification acquisition unit 23 acquires the tool specifications from the storage device 21 (S12: tool specification acquisition step). The tool specifications include information related to the shape and material of the gear machining tool T. Next, the tooth profile direction target dressing amount acquisition unit 24 acquires the tooth profile direction target dressing amount from the storage device 21 (S13: target dressing amount acquisition step). Next, the provisional design unit 26 provisionally designs the tool blade shape of the gear machining tool T based on the gear specifications, tool specifications, and tooth profile direction target dressing amount (S14: provisional design step). Since the tool blade shape of the gear machining tool T may be modified by the formal design process described later, the tool blade shape of the gear machining tool T is assumed to be the designed configuration. With the above, the provisional design process for the tool blade shape is completed.

[0099] (3) Correction Amount Determination Process

[0100] Next, if Figure 22 As shown, a correction amount determination process (S2) is executed. Through a gear machining simulation, multiple tooth surface shapes are calculated when one of the machining control elements, namely the Y-axis, is varied (S21: tooth surface shape calculation step). Next, based on the error between the gear tooth surface shape calculated through the gear machining simulation and the reference tooth surface shape, the correlation between the Y-axis variation ΔY and each trimming element is calculated (S22: correlation calculation step).

[0101] Next, a gear machining simulation is used to calculate multiple tooth surface shapes when the Cw axis, one of the machining control elements, is varied (S23: tooth surface shape calculation step). Next, based on the error between the gear tooth surface shape calculated by the gear machining simulation and the reference tooth surface shape, the correlation between the Cw axis variation ΔCw and each trimming element is calculated (S24: correlation calculation step).

[0102] Next, a gear machining simulation is used to calculate multiple tooth surface shapes when the B-axis, one of the machining control elements, is varied (S25: tooth surface shape calculation step). Next, based on the error between the tooth surface shape calculated by the gear machining simulation and the reference tooth surface shape, the correlation between the B-axis variation ΔY and each trimming element is calculated (S26: correlation calculation step). The order of calculating the correlations for the Y-axis, Cw-axis, and B-axis can be modified as appropriate.

[0103] Next, the correction amount determination unit 27 calculates the Y-axis correction amount ΔYa (S27: correction amount calculation step). For example, the correction amount determination unit 27 calculates the Y-axis correction amount ΔYa based on the target convex surface correction amount, the correlation between the Y-axis change ΔY and the convex surface correction amount Mc ( Figure 15 Calculate the Y-axis correction value ΔYa. Figure 15 The Y-axis change amount ΔY when the crowning amount Mc reaches the target correction amount is defined as the Y-axis correction amount ΔYa.

[0104] Next, the correction amount determination unit 27 calculates the correction amount ΔBa of the B axis (S28: correction amount calculation step). For example, the correction amount determination unit 27 calculates the correction amount ΔBa of the B axis based on the target correction amount of the offset, the change amount ΔB of the B axis, and the correction amount Mb of the offset ( Figure 16 The offset adjustment amount Mb ( Figure 15 For example, when determining the correction amount ΔYa of the Y axis, the offset adjustment amount Mb ( Figure 15 The middle section of Figure 16 When the total of the offset trimming amount Mb is consistent with the target trimming amount Figure 16 The offset adjustment amount Mb. Figure 16 The change amount ΔB of the B axis when the offset trimming amount Mb is set is set as the correction amount ΔBa of the B axis.

[0105] Next, the correction amount determination unit 27 calculates the correction amount ΔCwa of the Cw axis (S29: correction amount calculation step). For example, the correction amount determination unit 27 calculates the correction amount Mh of the tooth trace inclination based on the target correction amount of the tooth trace inclination, the change amount ΔCw of the Cw axis, and the correction amount Mh of the tooth trace inclination ( Figure 17 The lower part of the figure), the tooth line inclination adjustment amount Mh ( Figure 15The lower part of the figure), the tooth line inclination correction amount Mh ( Figure 16 For example, when determining the correction amount ΔYa of the Y axis, the tooth line inclination adjustment amount Mh ( Figure 15 The tooth line inclination adjustment amount Mh ( Figure 16 (lower part of the figure) and Figure 17 When the total amount of tooth line inclination trimming Mh is consistent with the target trimming amount Figure 17 The tooth line inclination adjustment amount Mh. Figure 17 The change amount ΔCw of the Cw axis when the tooth trace inclination is trimmed by the amount Mh is defined as the correction amount ΔCwa of the Cw axis.

[0106] Next, the correction amount determination unit 27 calculates the correction amounts Mc', Mb', and Mh' of the crown, offset, and tooth line inclination (S30: correction amount calculation step). The correction amounts Mc', Mb', and Mh' of each correction element are calculated based on the Y-axis correction amount ΔYa, the B-axis correction amount ΔBa, the Cw-axis correction amount ΔCwa, and the respective correlations. For example, the crown correction amount Mc ( Figure 15 The upper part of the figure), the convex surface correction amount Mc when the B-axis correction amount ΔBa ( Figure 16 The convex surface correction amount Mc ( Figure 17 The crowning amount Mc' is calculated from the total value of the upper diagram of FIG. The same applies to the offset and tooth line inclination trimming amounts Mb' and Mh'.

[0107] Next, the correction amount determination unit 27 determines whether the crown, offset, and tooth line inclination adjustment amounts Mc', Mb', and Mh' approximate their respective target adjustment amounts (S31: determination step). If the adjustment amounts Mc', Mb', and Mh' do not approximate their respective target adjustment amounts (S31: No), the correction amount determination unit 27 returns to step S27 and repeats the above-described process. For example, if the crown adjustment amount Mc' deviates from the target adjustment amount, the correction amounts ΔYa, ΔBa, and ΔCwa for each adjustment element are calculated to compensate for the deviation.

[0108] As described above, the correction amount determination unit 27 sequentially calculates the correction amount ΔYa of the Y axis, the correction amount ΔBa of the B axis, and the correction amount ΔCwa of the Cw axis. Figures 15 to 17As shown, the reason for this is that the changes in the trimming amounts Mc, Mb, and Mh for each trimming element decrease in the order of the Y-axis, B-axis, and Cw-axis. Specifically, the Y-axis influence of the B-axis is smaller, while the Y-axis and B-axis influences of the Cw-axis are smaller. This relationship allows the trimming amounts Mc', Mb', and Mh' for each trimming element to quickly approach their respective target trimming amounts, even with simple calculations. This reduces the number of iterations of steps S27 through S31 in determining the correction amounts ΔYa, ΔBa, and ΔCwa for the Y-axis, B-axis, and Cw-axis.

[0109] If the respective dressing amounts Mc', Mb', and Mh' approximate the respective target dressing amounts in S31 (S31: Yes), the correction amount determination unit 27 determines the calculated correction amounts ΔYa, ΔBa, and ΔCwa for the Y-axis, B-axis, and Cw-axis machining control elements (S32: Correction amount determination step). Therefore, the correction amounts ΔYa, ΔBa, and ΔCwa for each dressing element can be calculated using very simple calculations. The simple calculations mentioned here are simpler than those performed by gear machining simulations.

[0110] (4) Formal design process

[0111] Then, if Figure 23 As shown, the first tooth surface shape calculation unit 28 calculates the first tooth surface shape of the gear through a gear machining simulation using the machining control elements, namely, the correction amounts ΔYa, ΔBa, and ΔCwa, for the Y-axis, B-axis, and Cw-axis, determined by the correction amount determination unit 27 (S33: first tooth surface shape calculation step). The first target error calculation unit 29 acquires the calculated first tooth surface shape (S34: first tooth surface shape acquisition step). The first target error calculation unit 29 compares the first tooth surface shape with the target tooth surface shape and calculates a first target error in the tooth profile direction within the first tooth surface shape (S35: first target error calculation step). The first target error is an error associated with at least one of the pressure angle and the tooth profile fillet.

[0112] like Figure 24 As shown, the first target error is calculated based on the shape of the tooth surface Gf in the axial perpendicular section PA at the center position of the tooth G of the gear in the tooth width direction Wd.

[0113] Next, the final design unit 30 acquires the target tooth profile direction correction amount from the storage device 21 (S36: target correction amount acquisition step). The final design unit 30 calculates the first target error correction amount to reduce the first target error calculated by the first tooth surface shape calculation unit 28 (S37: first target error correction amount calculation step). Based on the target tooth profile direction correction amount and the first target error correction amount, the final design unit 30 corrects the tool edge shape of the gear machining tool T in the tooth profile direction, thereby formally designing the tool edge shape of the gear machining tool T (S38: final design step).

[0114] (5) Second Object Error Calculation Process

[0115] Then, if Figure 25 As shown, the second tooth surface shape calculation unit 31 obtains the correction amounts ΔYa, ΔBa, and ΔCwa for the Y-axis, B-axis, and Cw-axis, which are the machining control elements determined by the correction amount determination unit 27 (S41: correction amount acquisition step), and obtains the tool blade shape of the gear machining tool T formally designed by the formal design unit 30 (S42: tool blade shape acquisition step). Based on the correction amounts for the machining control elements and the formally designed tool blade shape, the second tooth surface shape calculation unit 31 calculates the second tooth surface shape of the gear through a gear machining simulation (S43: second tooth surface shape calculation step).

[0116] The second target error calculation unit 32 obtains the target tooth surface shape included in the gear specifications from the storage device 21 (S44: target tooth surface shape acquisition step). The second target error calculation unit 32 compares the second tooth surface shape with the target tooth surface shape and calculates a second target error in the second tooth surface shape (S45: second target error calculation step). The second target error includes both an error in the tooth profile direction and an error in the tooth trace direction, or one of both.

[0117] (6) Redesign process

[0118] When the second target error occurs in the tooth profile direction trimming element, the redesigning unit 33 redesigns the tool edge shape by trimming the tool edge shape of the gear machining tool T. Figure 26 As shown, the redesign unit 33 acquires the target tooth profile direction correction amount from the storage device 21 (S51: target correction amount acquisition step). The redesign unit 33 corrects the elements in the tooth profile direction and calculates the second target error correction amount for reducing the second target error (S52: second target error calculation step). Based on the target tooth profile direction correction amount and the second target error correction amount, the redesign unit 33 corrects the tool edge shape of the gear machining tool T in the tooth profile direction, thereby redesigning the tool edge shape (S53: tool edge shape redesign step).

[0119] (7) Correction amount redetermination process

[0120] The correction amount re-determining unit 34 re-determines the correction amount of the machining control element when the second target error occurs in the tooth trace direction trimming element. Figure 27 As shown, the correction amount re-determining unit 34 obtains the target tooth trace direction trimming amount from the storage device 21 (S61: target trimming amount obtaining step). The correction amount re-determining unit 34 calculates a second target error trimming amount for the tooth trace direction trimming element to reduce the second target error (S62: second target error calculating step). Based on the target tooth trace direction trimming amount and the second target error trimming amount, the correction amount re-determining unit 34 re-determines the correction amount for the machining control element (S63: correction amount re-determining step). This completes the entire process.

[0121] 9. Examples

[0122] Next, an example will be described in which this embodiment is applied to a specific gear machining tool T. Table 1 shows the target dressing amount in the tooth profile direction and the target dressing amount in the tooth trace direction of the gear machining tool T of this example.

[0123] [Table 1]

[0124]

[0125] In this example, the target adjustment factors in the tooth profile direction, namely the pressure angle adjustment amount and the tooth profile fillet adjustment amount, are 0.0 μm. The target adjustment factors in the tooth trace direction, namely the tooth line inclination adjustment amount, the crowning adjustment amount, and the offset adjustment amount, are 5.0 μm, 5.0 μm, and 10.0 μm, respectively.

[0126] By executing the temporary design process of the tool blade shape for the gear machining tool T of this example, the temporary designed tool blade shape ( Figure 20 of S1).

[0127] Next, a correction amount determination process is executed based on the target tooth trace direction trimming amount, thereby determining the correction amount of the machining control element in the machining operation ( Figure 20 S2).

[0128] Next, the first tooth surface shape of the gear is calculated based on the correction amount of the machining control element and the temporarily designed tool edge shape ( Figure 23 S33). Compare the calculated first tooth surface shape with the target tooth surface shape, and calculate the first target error ( Figure 23 S35).

[0129] As shown in Table 1, in this example, the first target error for the target modification elements in the tooth profile direction was 0.6 μm. Specifically, the first target error for the pressure angle was 0.6 μm, and the first target error for the tooth profile fillet was 0.2 μm. Meanwhile, the first target error for the target modification elements in the tooth trace direction (tooth trace inclination, crown, and offset) was 0.0 μm.

[0130] When machining control elements during machining are corrected based on the target trimming amount in the tooth trace direction, the correction changes the movement path of the gear machining tool T during machining. Consequently, the shape removed from the workpiece by the gear machining tool T changes. As a result, a first target error is considered to occur between the calculated first tooth surface shape and the target tooth surface shape in the tooth profile direction.

[0131] Next, for the pressure angle and the tooth profile fillet, the first target error correction amount ( Figure 23 S37).

[0132] For the pressure angle, the target adjustment amount in the tooth profile direction is 0.0 μm, and the first target error is 0.6 μm, so the first target error adjustment amount is calculated as -0.6 μm. Furthermore, for the tooth profile fillet, the target adjustment amount in the tooth profile direction is 0.0 μm, and the first target error is 0.2 μm, so the first target error adjustment amount is calculated as -0.2 μm.

[0133] Next, the tool edge shape ( Figure 23 S38).

[0134] Next, the second tooth surface shape of the gear is calculated based on the correction amount of the machining control element and the tool edge shape of the gear machining tool T that is formally designed ( Figure 25 Compare the calculated second tooth surface shape with the target tooth surface shape, and calculate the second target error ( Figure 25 The second target error may include both the error in the tooth profile direction and the error in the tooth trace direction, or may include only one of them.

[0135] As shown in Table 1, in this example, no second target error occurs. Specifically, the first target error for the pressure angle and the second target error for the tooth profile fillet are 0.0 μm, and the second target error for the tooth line inclination, crown, and offset is 0.0 μm.

[0136] 10. The effect of this method

[0137] In this method, the second object error does not occur, so in the redesign process of the tool blade shape ( Figure 20 In S5) of the tool blade shape is not redesigned, and the correction amount is re-determined ( Figure 20 The correction amount is not redetermined in S6).

[0138] According to this example, machining control elements during machining are corrected based on the target tooth trace direction trimming amount, resulting in a first target error. The tool edge shape of the gear machining tool T is then formally designed based on the first target error trimming amount to reduce the first target error. Consequently, even when machining control elements are corrected based on the target tooth trace direction trimming amount, errors in the gear tooth surface shape in the tooth profile direction can be suppressed.

[0139] Furthermore, according to this method, the second tooth surface shape of the gear is calculated based on the correction amount of the machining control element and the officially designed tool blade shape. The calculated second tooth surface shape is then compared with the target tooth surface shape to calculate the second target error of the second tooth surface shape. Thus, by trimming the provisionally designed tool blade shape to the officially designed tool blade shape, even if an unexpected error occurs in the second tooth surface shape of the gear machined with the officially designed gear machining tool T, this error can be calculated as the second target error. This allows for handling even the occurrence of unexpected errors.

[0140] According to this method, when a second target error occurs, the tool edge shape is redesigned or the correction amount of the machining control element is re-determined based on the second target error correction amount to reduce the second target error. This prevents errors in the gear tooth surface shape from occurring when the provisionally designed tool edge shape is corrected to the final designed tool edge shape.

[0141] (Implementation Method 2)

[0142] Next, refer to Figure 28 Implementation 2 is described. Figure 28 As shown, in this embodiment, in the correction amount determination process (S2), the correction amount is determined based on the shape of the tooth surface Gf in the axial perpendicular section PA at any one position of the gear tooth G in the tooth width direction Wd.

[0143] In the following description, the same reference numerals are given to the same components as those in Embodiment 1, and redundant description is omitted.

[0144] According to this embodiment, for example, the first target error can be calculated based on a cross-section perpendicular to the axis at a location affected by the error in the tooth width direction Wd of the gear tooth G. This improves the calculation accuracy of the first target error.

[0145] (Implementation 3)

[0146] Next, refer to Figure 29 Implementation 3 is described. Figure 29 As shown, in this embodiment, the first target error ( Figure 23 In this method, for example, the first target error can be calculated based on the average of the errors in the two axially perpendicular sections PA1 and PA2. According to this method, by using the axially perpendicular sections PA1 and PA2 at multiple locations as a reference, the calculation accuracy of the first target error can be improved.

[0147] (Implementation 4)

[0148] Next, refer to Figure 30 Implementation 4 is described. Figure 30 As shown, in this embodiment, the first target error ( Figure 23 In this method, for example, the first target error can be calculated based on the average value of the errors across the entire range in the tooth width direction Wd of the gear teeth G. According to this method, by using the entire range in the tooth width direction Wd of the gear teeth G as a reference, the calculation accuracy of the first target error can be improved.

[0149] (Implementation 5)

[0150] Next, refer to Figure 31 Implementation 5 will be described. Figure 31 As shown, in this embodiment, the first target error ( Figure 23 In this method, for example, in the tooth width direction Wd of the gear tooth G, the first target error can be calculated based on the range A affected by the error. This can improve the calculation accuracy of the first target error.

Claims

1. A method for designing a gear machining tool, wherein an axis parallel to a central axis (RT) of a gear machining tool (T) has a predetermined axis intersection angle (α) with respect to a central axis (RW) of a workpiece (W), the gear machining tool and the workpiece are rotated synchronously while the workpiece and the gear machining tool are relatively moved, thereby machining a gear tooth (G) on the workpiece, wherein: The design method of the gear processing tool has the following features: Step (S1), obtaining the specification of the gear, i.e., the gear specification, obtaining the specification of the gear processing tool, i.e., the tool specification, obtaining the target value of the tooth profile direction trimming element of the tooth surface shape of the gear, i.e., the tooth profile direction target trimming amount, and temporarily designing the tool blade shape of the gear processing tool based on the gear specification, the tool specification, and the tooth profile direction target trimming amount; Step (S2), obtaining a target value of a tooth trace direction trimming element of the tooth surface shape, that is, a target tooth trace direction trimming amount, and determining a correction amount of a machining control element in a machining operation based on the target tooth trace direction trimming amount; Step (S33), calculating a first tooth surface shape of the gear based on the correction amount of the machining control element and the provisionally designed tool edge shape; Step (S35), comparing the calculated first tooth surface shape with a target tooth surface shape included in the gear specification, and calculating a first target error in the tooth profile direction in the first tooth surface shape; and In step (S38), the tool edge shape is formally designed based on the target correction amount in the tooth profile direction and the first target error correction amount for reducing the first target error.

2. The method for designing a gear machining tool according to claim 1, wherein: have: Step (S43), calculating a second tooth surface shape of the gear based on the correction amount of the machining control element and the formally designed tool edge shape; as well as The step (S45) is to compare the calculated second tooth surface shape with the target tooth surface shape included in the gear specification, and calculate a second target error of the second tooth surface shape.

3. The method for designing a gear machining tool according to claim 2, wherein: A process (S53, S63) is provided for redesigning the tool blade shape or re-determining the correction amount of the machining control element based on at least one of the target trimming amount in the tooth profile direction and the target trimming amount in the tooth line direction and a second object error trimming amount for reducing the second object error.

4. The method for designing a gear machining tool according to claim 1, wherein: The first target error in the tooth profile direction in an axis-perpendicular section (PA) at one location in the tooth width direction (Wd) of the gear is calculated.

5. The method for designing a gear machining tool according to claim 4, wherein: The first target error in the tooth profile direction in an axially perpendicular cross section at one center point in the tooth width direction is calculated.

6. The method for designing a gear machining tool according to claim 1, wherein: The first target error is calculated based on errors in the tooth profile direction calculated in axis-orthogonal sections (PA1, PA2) at a plurality of locations in the tooth width direction of the gear.

7. The method for designing a gear machining tool according to claim 1, wherein: The first target error is calculated based on the error in the tooth profile direction calculated in the entire range in the tooth width direction of the gear.

8. The method for designing a gear machining tool according to claim 1, wherein: The first object error is calculated based on the error in the tooth profile direction calculated in a partial range (A) in the tooth width direction of the gear.

9. The method for designing a gear machining tool according to any one of claims 1 to 8, wherein: The tooth profile direction modification element includes at least one of a pressure angle and a tooth profile fillet. The tooth trace direction modification element includes at least one of a convex surface, an offset, and a tooth trace inclination.

10. The method for designing a gear machining tool according to any one of claims 1 to 8, wherein: The corrected processing control elements include the axis intersection angle (α), the deviation angle (γ) indicating the position of the gear processing tool in the circumferential direction of the workpiece, the center-to-center distance (D) between the center axis of the workpiece and the center axis of the gear processing tool, and at least one of the relative rotation speeds of the workpiece and the gear processing tool.

11. A design support device (20) for a gear machining tool, wherein an axis parallel to a central axis (RT) of the gear machining tool (T) has a predetermined axis intersection angle (α) relative to a central axis (RW) of a workpiece (W), the gear machining tool and the workpiece are rotated synchronously while the workpiece and the gear machining tool are relatively moved, thereby machining a gear tooth (G) on the workpiece, wherein: The gear machining tool design assisting device (20) comprises: A gear specification acquisition unit (22) acquires the specification of the gear, i.e., the gear specification; A tool specification acquisition unit (23) acquires the specification of the gear processing tool, i.e., the tool specification; A tooth profile direction target trimming amount acquisition unit (24) acquires a target value of a tooth profile direction trimming element of the tooth surface shape of the gear, namely, a tooth profile direction target trimming amount; A temporary design unit (26) temporarily designs a tool edge shape of the gear processing tool based on the gear specifications, the tool specifications and the target dressing amount in the tooth profile direction; A tooth trace direction target trimming amount acquisition unit (25) is configured to acquire a target value of a tooth trace direction trimming element of the tooth surface shape, namely, a tooth trace direction target trimming amount; A correction amount determination unit (27) determines a correction amount of a machining control element in a machining operation based on the target trimming amount in the tooth trace direction; A first tooth surface shape calculation unit (28) calculates a first tooth surface shape of the gear based on the correction amount of the machining control element and the temporarily designed tool edge shape; A first object error calculation unit (29) compares the calculated first tooth surface shape with a target tooth surface shape included in the gear specification, and calculates a first object error in the tooth surface shape in the tooth profile direction; as well as A formal design section (30) formally designs the tool edge shape based on the tooth profile direction target correction amount and a first target error correction amount for reducing the first target error.

12. The design support device for a gear machining tool according to claim 11, wherein: have: A second tooth surface shape calculation unit (31) calculates a second tooth surface shape of the gear based on the correction amount of the machining control element and the formally designed tool edge shape; as well as A second target error calculation unit (32) compares the calculated second tooth surface shape with a target tooth surface shape included in the gear specifications, and calculates a second target error of the second tooth surface shape.

13. The design support device for a gear machining tool according to claim 12, wherein: A redesign section (33) for redesigning the tool blade shape based on at least one of the target trimming amount in the tooth profile direction and the target trimming amount in the tooth line direction and a second object error trimming amount for reducing the second object error, or a correction amount redetermination section (34) for redetermining the correction amount of the machining control element.

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