Method for designing a gear machining tool and design support device for a gear machining tool

Abstract

A method for designing a gear cutting tool (T) comprises: a step (S1) of acquiring gear specifications, tool specifications, and a target tooth profile direction modification amount, and designing a preliminary shape of a tool cutting edge of the gear cutting tool based on the gear specifications, the tool specifications, and the target tooth profile direction modification amount; a step (S2) of acquiring a target tooth flank direction modification amount; determining a correction amount of a machining control element based on the target tooth flank direction modification amount; a step (S33) of calculating a first tooth flank shape of the gear based on the correction amount of the machining control element and the preliminary designed tool cutting edge shape;a step (S35) of comparing the first tooth flank shape with a target tooth flank shape and calculating a first target deviation of the first tooth flank shape in the tooth profile direction; and a step (S38) of fully designing the tool cutting edge shape based on the target tooth profile direction modification amount and a first target deviation correction amount for reducing the first target deviation.

Description

TECHNICAL FIELDThe present invention relates to a method for designing a gear machining tool and a design support device for a gear machining tool.PRIOR ARTWhen gears are subjected to a load, the teeth or shafts may deform and the engagement state may deteriorate. Therefore, noise may be generated. There is an increasing demand for quiet gears which achieve ideal tooth meshing under load. Therefore, it is necessary to modify the tooth flank shape. The modification elements of the tooth flank shape of the gear include, for example, the inclination of the tooth flank line (also referred to as "tooth flank line helix"), the crowning, the prestress, the angle of engagement and the tooth profile roundness. Of these modification elements, the tooth trace inclination, the crowning, and the preload are modification elements in a tooth trace direction of the gear, and the engagement angle and the tooth profile roundness are modification elements in a tooth profile direction of the gear (direction from a tooth root to a tooth tip).Japanese Unexamined Patent Application No. 2021-11 011 (JP 2021-11 011 A) (Patent Document 1) describes a technology in which additional movement for changing the modification member in the tooth trace direction of the gear is provided to the gear machining tool to change the modification member in the tooth trace direction. Thereby, improvement in the accuracy of the gear in the tooth trace direction is expected.Prior Art DocumentsPatent DocumentsPatent Document 1: Japanese Unexamined Patent Application, Publication No. 2021-11 011 (JP 2021-11 011 A)SUMMARY OF THE INVENTIONProblem to be Solved by the InventionHowever, in the above technology, when the gear is machined by providing the additional movement to the gear machining tool, the accuracy in the tooth trace direction of the gear is improved, but a problem arises because a deviation in the shape occurs in the tooth profile direction of the gear.The present invention has been made in view of the above problem, and provides a method for constructing a gear machining tool capable of correcting deviations with respect to a tooth trace direction and a tooth profile direction of a gear, and a design support device for a gear machining tool.Means for Solving the ProblemAn aspect of the present invention is a method of designing a gear machining tool configured to machine teeth of a gear on a workpiece by relative movement of the workpiece and the gear machining tool while synchronously rotating the gear machining tool and the workpiece in a state in which an axis parallel to a central axis of the gear machining tool has a predetermined axis cut angle with respect to a central axis of the workpiece. The method includes: a step of acquiring gear specifications that are specifications of the gear, acquiring tool specifications that are specifications of the gear machining tool, acquiring a target tooth profile direction modification amount that is a target value of a tooth profile direction modification element of a tooth flank shape of the gear, and preliminarily designing a tool edge shape of the gear machining tool on the basis of the gear specifications, the tool specifications, and the target tooth profile direction modification amount; a step of acquiring a Sollzahnflankenlinienrichtungsmodifikationsbetrags that is a target value of a tooth flank line direction modification element of the tooth flank shape, and determining a correction amount of a machining control element during a machining operation on the basis of the Sollzahnflankenlinienrichtungsmodifikationsbetrags; a step of calculating a first tooth flank shape of the gear based on the correction amount of the machining control element and the preliminarily designed tool edge shape; a step of comparing the calculated first tooth flank shape with a target tooth flank shape indicated in the specifications of the gear and calculating a first target deviation of the first tooth flank shape toward the tooth profile; and a step of fully designing the tool edge shape based on the modification amount of the target direction of the tooth profile and a first target deviation correction amount for reducing the first target deviation.Another aspect of the present invention is a design support device for a gear machining tool configured to machine teeth of a gear on a workpiece by moving the workpiece and the gear machining tool relative to each other while synchronously rotating the gear machining tool and the workpiece in a state in which an axis parallel to a central axis of the gear machining tool has a predetermined axis intersection angle with respect to a central axis of the workpiece. The design support device includes: a gear specification acquisition unit configured to acquire gear specifications, i.e., specifications of the gear; a tool specification acquisition unit configured to acquire tool specifications, i.e., specifications of the gear machining tool; a target tooth profile direction modification amount acquisition unit configured to acquire a target tooth profile direction modification amount, which is a target value of a tooth profile direction modification element of a tooth profile shape of the gear; a provisional design unit configured to discard a provisional shape of a tool blade of the gear machining tool based on the gear specifications, the tool specifications, and the target tooth profile direction modification amount; a target tooth flank line direction modification amount obtaining unit that is a target value of a tooth flank line direction modification element of the tooth flank shape; a correction amount determining unit configured to determine a correction amount of a machining control unit element during a machining operation based on the target tooth flank direction modification amount; a first tooth flank shape calculating unit configured to calculate a first tooth flank shape of the gear based on the correction amount of the machining control unit element and the preliminarily designed tool edge shape; a first target deviation calculating unit configured to compare the calculated first tooth flank shape with a target tooth flank shape indicated in the wheel specifications and calculate a first target deviation of the tooth flank shape toward the tooth profile; A full design unit configured to fully design the tool cutting shape based on the modification amount of the target tooth profile direction and a first target deviation correction amount for reducing the first target deviation.Effect of the inventionIn one and the other aspects of the present invention, the shape of the tool edge of the gear machining tool T is entirely designed based on the first target deviation correction amount for reducing the first target deviation included by the correction of the machining control member during the machining operation based on the modification amount of the target tooth flank direction. Therefore, it is possible to suppress the occurrence of the tooth flank shape deviation of the gear in the tooth profile direction even when the machining control element is corrected based on the modification amount of the target tooth flank direction.Reference numerals in parentheses in the claims indicate correspondence with the means described particularly in the embodiments below, and are not intended to limit the technical scope of the present invention.BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a perspective view showing a machining apparatus according to a first embodiment. FIG. 2 is a schematic diagram showing a workpiece and a gear machining tool in a gear machining method, as viewed in the radial direction of the gear machining tool when an axis crossing angle is set. FIG. 3 is a schematic diagram of FIG. 2 as viewed in the direction of the central axis of the gear machining tool. FIG. 4 is a schematic diagram illustrating an operation of the gear peeling method as viewed in the radial direction of the gear machining tool. FIG. 5 is a schematic diagram of FIG. 4 as viewed in the direction of the central axis of the machining tool. FIG. 6 is a schematic diagram of the workpiece and the gear machining tool in the gear machining method when an offset angle is set, as viewed in the radial direction of the gear machining tool. FIG. 7 is a schematic diagram showing a modification of the crowning as a modification member. FIG. 8 is a schematic diagram showing a modification of biasing as a modification member. FIG. 9 is a schematic diagram showing a modification of the inclination of the tooth flank as a modification member. FIG. 10 is a schematic diagram showing an engagement angle modification as a modification element. FIG. 11 is a schematic diagram showing a change amount of tooth profile roundness as a modification member. FIG. 12 is a schematic diagram showing a motion for parabolically changing a center distance between a center axis of the gear machining tool and a center axis of the workpiece with respect to a tooth width position. FIG. 13 is a schematic diagram showing a movement for linearly changing the angle at which the axes intersect between the central axis of the gear machining tool and the central axis of the workpiece with respect to the tooth width position. FIG. 14 is a schematic diagram showing a movement for linearly changing a rotation angle of the workpiece relative to a rotation angle of the gear machining tool with respect to the tooth width position. FIG. 15 is a schematic diagram showing a correlation between a change amount in a Y axis and the crowning modification amount, a correlation between the change amount in the Y axis and the preload modification amount, and a correlation between the change amount in the Y axis and the tooth flank line inclination modification amount. FIG. 16 is a schematic diagram showing a correlation between a change amount in a B axis and the crowning modification amount, a correlation between the change amount in the B axis and the preload modification amount, and a correlation between the change amount in the B axis and the tooth flank line inclination modification amount. FIG. 17 is a schematic diagram showing a correlation between a change amount in a Cw axis and the crowning modification amount, a correlation between the change amount in the Cw axis and the preload modification amount, and a correlation between the change amount in the Cw axis and the tooth flank line inclination modification amount. FIG. 18 is a schematic diagram showing a correlation between change amounts in an X axis and the Y axis and the crowning modification amount, a correlation between the change amounts in the X axis and the Y axis and the preload modification amount, and a correlation between the change amounts in the X axis and the Y axis and the tooth trace inclination modification amount. FIG. 19 is a diagram showing the configuration of a design support device according to the first embodiment. FIG. 20 is a flowchart showing an operation of the design support device and a main flow of a design method. FIG. 21 is a flowchart showing a provisional design process for a tool blade shape. FIG. 22 is a flowchart showing a correction amount determination process. FIG. 23 is a flowchart showing a complete construction process. FIG. 24 is a perspective view showing a state in which a first target deviation is calculated on the basis of a cross section perpendicular to the axis at a position at the center of a gear in the tooth width direction. FIG. 25 is a flowchart showing a second deviation calculation process. FIG. 26 is a flowchart showing a redesign process. FIG. 27 is a flowchart showing a process for re-determining a correction amount. FIG. 28 is a perspective view showing a state in which the first target deviation is calculated on the basis of a cross section perpendicular to the axis at an arbitrary position on the gear in the tooth width direction according to a second embodiment. FIG. 29 is a perspective view showing a state in which the first command value deviation according to a third embodiment is based on cross sections that are perpendicular to the axis at a plurality of locations on the gear in the tooth width direction. FIG. 30 is a perspective view showing a state in which the first target deviation is calculated based on the entire range of the gear in the tooth width direction according to a fourth embodiment. FIG. 31 is a perspective view showing a state in which the first target deviation is calculated based on a partial region of the gear in the tooth width direction according to a fifth embodiment.MODES FOR CARRYING OUT THE INVENTION(First Embodiment)1. Configuration of a Gear Machining ApparatusA design method and a design support device for a gear machining tool (also referred to as a "gear cutting cutter" ("gear curving cutter")) according to a first embodiment of the present invention are applied to the design of a gear machining tool for machining a workpiece. In the present 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.The configuration of the gear machining apparatus will be described with reference to FIG. 1. In the present embodiment, a gear machining apparatus 1 machines gear teeth on a workpiece W by moving the workpiece W and a gear machining tool T relative to each other while synchronously rotating the gear machining tool T and the workpiece W in a state in which an axis parallel to a central axis RT of the gear machining tool T has a predetermined axis intersection angle α with respect to a central axis RW of the workpiece W.As can be seen from FIG. 1, the gear machining apparatus 10 is, for example, a five-axis machining center having three linear axes and two rotation axes as drive axes for changing the relative positions and postures of the workpiece W and the gear machining tool T. The present embodiment of the gear machining apparatus 10 has three perpendicular axes (X axis, Y axis, Z axis) as linear axes and a B axis and a Cw axis as rotating axes. In the present embodiment, the B axis is a rotation axis about a center axis RB of a rotary table 14 that is parallel to the Y axis, and the Cw axis is a rotation axis about the center axis RW of the workpiece W. The gear machining apparatus 10 has a Ct axis that is a rotation axis about the center axis RT of the gear machining tool T, and is a machining center having six axes when the Ct axis is included.The gear machining apparatus 10 has a tool spindle 11 that holds the gear machining tool T and is rotatable about the Ct axis and movable in the Y axis and Z axis directions. The gear machining apparatus 10 further includes a workpiece spindle 12 that supports the workpiece W and is rotatable about the Cw axis, rotatable about the B axis, and movable in the X axis direction. The present embodiment illustrates a case where gear teeth on the workpiece W are machined by a gear peeling operation. The present invention is not limited to the above configuration, and the tool spindle 11 and the workpiece spindle 12 may be configured in any manner as long as they are movable relative to each other.2. Machining MethodThe rolling-up process (planing) will be described with reference to FIGS. 2, 3, 4, 5 and 6. In the gear cutting method, as shown in FIGS. 2 and 3, the central axis RT of the gear machining tool T is set to have the axis crossing angle α with respect to an axis parallel to the central axis RW of the workpiece W. When viewed in the X-axis direction, the central axis RT of the gear machining tool T and the central axis RW of the workpiece W are parallel to each other. The distance between the center of the center axis RT of the gear machining tool T and the center of the center axis RW of the workpiece W is represented by D.As can be seen from FIGS. 4 and 5, the method is to machine the gear teeth of the workpiece W by feeding the gear tool T toward the central axis RW of the workpiece W relative to the workpiece W while synchronizing the rotation of the workpiece W about the central axis RW of the workpiece W and the rotation of the gear tool T about the central axis RT of the gear tool T. In the gear machining method, each portion of the tooth gap of the workpiece W is machined only once by the gear machining tool T while the workpiece W rotates once.FIG. 6 shows an offset angle γ. The offset angle γ is an angle when a machining point between the gear machining tool T and the workpiece W is displaced in a circumferential direction of the workpiece W. A reference position at which the offset angle γ is zero is a position of the gear machining tool T corresponding to a machining point at which a center distance D is the largest when the center axis RT of the gear machining tool T and the center axis RW of the workpiece W are parallel and viewed in a direction perpendicular to the center axis RW of the workpiece W (X-axis direction in the present embodiment) when the machining point is changed in the circumferential direction of the workpiece W.3. Tooth Flank Modification ElementsTooth flank modification elements used for modifying the tooth flank shape of a gear will be described with reference to FIGS. 7 to 11. As can be seen from FIGS. 7 to 11, the modification elements in the shape of a tooth flank Gf of a gear tooth G have modification elements in a tooth flank line direction and modification elements in a tooth profile direction. The modification elements in the tooth flank direction have crowning (FIG. 7 ), prestress (FIG. 8 ), and inclination of the tooth flank (FIG. 9 ). The modification members in the tooth profile direction have an engagement angle (FIG. 10 ) and a tooth profile roundness (FIG. 11 ). The crowning means that the center of the tooth width in the tooth flank direction is higher than the both ends. The prestress means that the angle of engagement is continuously changed in the direction of the tooth flank in order to impart a spiral shape to the tooth flank.As is apparent from FIG. 7, an amount Mc of crowning modification is expressed as a distance of a portion through which a measurement diameter at a center position (surface width center in the present embodiment) of an evaluation region Dc passes toward the tooth flank Gf of the tooth G. As can be seen from FIG. 8, a preload modification amount Mb is expressed as a difference between the engagement angles Mp 1 and Mp 2 at both end positions (positions shifted by Db / 2 on both sides from the center of the tooth width in the present embodiment) of an evaluation range Db in the tooth flank direction on the tooth flank Gf of the tooth G.As can be seen from FIG. 9,A tooth flank line inclination modification amount Mh is expressed as a height difference in the tooth flank line direction between portions through which the measurement diameter at both end positions (position of an end surface of the tooth and tooth width center position in the present embodiment) of an evaluation range Dh in the tooth flank line direction passes on the tooth flank Gf of the tooth G.As can be seen from FIG. 10, an engagement angle modification amount Mp is expressed as inclination variation in the direction of the tooth height at a position in the center (tooth width position in the present embodiment) of an evaluation range Dp in the tooth flank direction on the tooth flank Gf of the tooth G. As can be seen from FIG. 11, a circularity modification amount Mr of a tooth profile is expressed as a projection amount of a tooth profile variation at a center position (tooth width position in the present embodiment) of an evaluation region Dr toward the tooth flank Gf of the tooth G.4. Fundamentals of the Tooth Flank Modification MethodAmong the tooth flank shape modification elements, the engagement angle and the circularity of the tooth profile are modifications toward the tooth profile and are modifications of a tool blade shape. That is, the modifications may be made based on the cutting shape of the gear machining tool T. Moreover, the modifications may be made based on specifications of the tool such as the number of cutting edges, a rack shift coefficient, a skew angle, a sharpness angle, and a rake angle. Among the modification elements of the tooth flank shape, the crowning, the preload, and the inclination of the tooth flank line direction, modifications are in the tooth flank line direction and are transmissions of a movement path of the gear machining device 10. The engagement angle and the roundness of the tooth profile may also be modified based on the control devices of the gear machining device 10, but in the present embodiment, are modified based on the shape of the tool blade (specifications) of the gear machining tool T.Specifically, as shown in FIG. 12, the crowning can be formed by providing a movement while parabolically changing the center distance D (shown in FIGS. 3 and 5 ) between the center axis RT of the gear machining tool T and the center axis RW of the workpiece W with respect to a tooth width position during the feeding in the tooth width direction. Therefore, the crowning can be changed by controlling the operation in the Y axis in the gear machining apparatus 10.As can be seen from FIG. 13, the preload can be formed by providing a movement while linearly changing the axis cutting angle α between the center axis RT of the gear machining tool T and the center axis RW of the workpiece W with respect to the tooth width position during the feeding in the tooth width direction. Therefore, the preload can be modified by controlling the operation of rotating the gear machining tool T about an axis parallel to the Y axis. In the gear machining apparatus 10, however, the gear machining tool T does not rotate. Therefore, the modification can be made by controlling the operation in the B axis, which is the rotational axis of the workpiece W (workpiece rotational angle (axis cutting angle α)).Although not illustrated, the bias may be formed by changing, during the feeding in the tooth width direction, the offset angle γ obtained when the machining point between the gear machining tool T and the workpiece W is shifted in the circumferential direction of the workpiece W. Therefore, the modification can be made by controlling the operations in the X axis and the Y axis in the gear machining apparatus 10.As can be seen from FIG. 14, the tooth flank line inclination can be formed by providing a movement while linearly changing a rotation angle β of the workpiece W relative to a rotation angle of the gear machining tool T with respect to the tooth width position during the advancement in the tooth width direction. Therefore, the tooth flank line inclination can be modified by controlling the operation in the Cw axis in the gear machining apparatus 10. The horizontal axes in FIGS. 12 to 14 represent tooth width positions of the machining point between the gear machining tool T and the workpiece W, i.e., a position on a right tooth flank on one end surface side of the tooth (machining start position) to a position on the right tooth flank on the other end surface side of the tooth (machining end position).5. Correlations between Modification Elements and Control Elements for ProcessingNext, the correlations between the modification elements and the control elements for the processing will be described with reference to FIGS. 15 to 18. The correlations between the modification elements and the control elements for machining vary depending on the specifications of the gear machining tool T. The specifications of the gear machining tool T are determined based on the specifications of a gear to be machined on the workpiece W. Therefore, the correlations shown in FIGS. 15 to 18 are correlations in a certain gear machining tool T and vary in another gear machining tool T. Examples of the modification elements are the crowning, the preload, and the tooth trace inclination, which are modification elements in the tooth trace direction. Examples of the control elements of the machining are the Y axis, the B axis, the Cw axis, and the off angle γ (two synchronous axes consisting of the X axis and the Y axis).FIG. 15 shows a correlation between a change amount ΔY in the Y axis and the crowning modification amount Mc, a correlation between the change amount ΔY in the Y axis and the preload modification amount Mb, and a correlation between the change amount ΔY in the Y axis and the tooth trace inclination modification amount Mh. Each correlation is calculated based on a deviation between a tooth flank shape obtained by a gear machining simulation and a reference tooth flank shape when the gear machining simulation is performed in a state where only the Y axis is changed by a reference machining control element.For example, each correlation between the modifying element and the machining control element is calculated using a quadratic function based on the tooth flank shape obtained by the gear machining simulation. Specifically, a deviation between the tooth flank shape obtained by the gear machining simulation and an involute helical tooth flank that is the reference tooth flank shape is calculated, and a correlation between the calculated deviation and the amount of change in the machining control element (Y axis) is calculated.Specifically, the gear machining simulation is first performed to calculate a plurality of tooth flank shapes by gradually changing the Y axis, which is the control element for machining. This process is sequentially performed to calculate the entire tooth flank shape. The correlations are obtained by calculating the crowning, biasing, and tooth trace inclination modification amounts Mc, Mb, and Mh that are the modification elements of each tooth trace shape in the tooth trace direction, and preparing graphs by associating the calculated crowning, biasing, and tooth trace inclination modification amounts Mc, Mb, and Mh with the change amount ΔY in the Y axis that is the machining control element.The change amount ΔY in the Y axis has a plurality of values changed from the reference value in the positive direction and a plurality of values changed from the reference value in the negative direction. As can be seen from FIG. 15, the crowning can be largely changed when the Y axis is changed. When the Y axis is changed, the preload and the tooth trace inclination are also changed.The gear machining simulation is described in, for example, Japanese Unexamined Patent Application No. 2017-144502 (JP 2017-144 502 A). The machining reference control element is a control element for machining a gear without crowning, preload, modified tooth flank line inclination, engagement angle, or tooth profile roundness. The modified tooth flank line slope means tooth flank line slope with respect to the reference tooth flank line slope, which is one of the gear specifications.FIG. 16 shows a correlation between a modification amount ΔB in the B axis and the crowning modification amount Mc, a correlation between the modification amount ΔB in the B axis and the preload modification amount Mb, and a correlation between the modification amount ΔB in the B axis and the tooth trace inclination modification amount Mh. Each correlation is calculated based on a deviation between the tooth flank shape of the gear obtained by the gear machining simulation and the reference tooth flank shape when the gear machining simulation is performed in a state where only the B axis is changed from the reference machining control element. The modification amount ΔB in the B axis is controlled based on the workpiece rotation angle (intercept angle 0).Diagrams showing the relationship between the crowning, biasing, and tooth flank line inclination modification amounts Mc, Mb, and Mh and the modification amount ΔB in the B axis which is the machining control element are prepared in substantially the same manner as in the Y axis described above. The modification amount ΔB in the B axis has a plurality of values changed from the reference value in the positive direction and a plurality of values changed from the reference value in the negative direction. As can be seen from FIG. 16, the bias voltage can be largely changed when the B axis is changed. When the B axis is changed, the crowning and the tooth flank line inclination are changed.FIG. 17 shows a correlation between a modification amount ΔCw in the Cw axis and the crowning modification amount Mc, a correlation between the modification amount ΔCw in the Cw axis and the bias modification amount Mb, and a correlation between the modification amount ΔCw in the Cw axis and the tooth trace inclination modification amount. Each correlation is calculated based on a deviation between the tooth flank shape of the gear obtained by the gear machining simulation and the reference tooth flank shape when the gear machining simulation is performed in a state where only the Cw axis is changed from the reference machining control element. The modification amount ΔCw in the Cw axis is controlled based on the workpiece rotation angle β.Diagrams showing the relationship between the crowning, biasing, and tooth flank line inclination modification amounts Mc, Mb, and Mh and the modification amount ΔCw in the Cw axis, which is the machining control element, are prepared in substantially the same manner as in the Y axis described above. The modification amount ΔCw in the Cw axis has a plurality of values changed from the reference value in the positive direction and a plurality of values changed from the reference value in the negative direction. As can be seen from FIG. 17, the tooth trace inclination can be largely changed when the Cw axis is changed. When the Cw axis is changed, the crowning and the preload are hardly changed.FIG. 18 shows correlations between a change amount in the offset angle γ and the modification elements. The offset angle γ is an angle when the machining point between the gear machining tool T and the workpiece W is displaced in the direction of the circumference of the workpiece W. Therefore, the offset angle γ can be expressed by synchronizing the X axis and the Y axis. That is, the amount of change in the offset angle γ can be expressed by the amounts of change ΔX and ΔY in the two synchronous axes, the X axis and the Y axis. Hereinafter, the change amount of the offset angle γ is represented by ΔX, ΔY.That is, FIG. 18 shows a correlation between the amount of change ΔX, Y in the offset angle γ and the crowning modification amount Mc, a correlation between the amount of change ΔX, Y in the offset angle γ and the preload modification amount Mb, and a correlation between the amount of change ΔX, Y in the offset angle γ and the tooth trace inclination modification amount Mh. Each correlation is calculated based on a deviation between the tooth flank shape of the gear obtained by the gear machining simulation and the reference tooth flank shape when the gear machining simulation is performed in a state where only the offset angle γ from the reference machining control element is changed.Diagrams showing the relationship between the crowning, biasing, and tooth flank line inclination modification amounts Mc, Mb, and Mh and the change amount ΔX, ΔY of the offset angle γ, which is the machining control element, are prepared in substantially the same manner as in the Y axis described above. As can be seen from FIG. 18, the bias voltage can be largely changed when the offset angle γ is changed. When the offset angle γ is changed, the crowning and the tooth flank line inclination are also changed.From the above, it is understood that the modification elements and the machining control elements influence each other. Therefore, even if one modification element is modified, the other modification elements are affected. Therefore, the modification is necessary for the other modification elements. In the above, each machining control element (Y axis, B axis, Cw axis, displacement angle γ) is changed exclusively, but a plurality of elements may be changed synchronously based on a certain synchronization condition. Also in this case, it is possible to obtain the correlations between the machining control elements and the modification elements.6. Method for Calculating Deviation from Reference Tooth FlankAs described above, each correlation is based on the deviation between the tooth flank shape obtained when each machining control element is changed and the reference tooth flank shape. The reference tooth flank shape is, for example, an involute toothing. The method for calculating the deviation from the reference tooth flank is described, for example, in JP 2021-11 011 A.7. Configuration of Design Support Device 20The configuration of a design support device 20 will be described with reference to FIG. 19. The design assist device 20 is a device capable of assisting in machining gear teeth by modifying the tooth flank shape. The design support device 20 may be, for example, an embedded system (microcomputer) such as an PLC (Programmable Logic Controller) or a CNC (Computerized Numerical Control) device, or a personal computer or a server.As is apparent from FIG. 19, the design support device 20 has a storage device 21 that stores gear specifications that are the specifications of the gear, tool specifications that are the specifications of the gear machining tool T, target tooth profile direction modification amounts that are target values of tooth profile direction modification elements of the tooth flank shape of the gear, and Sollzahnflankenlinienrichtungmodifikationsbeträge that are target values of tooth flank line direction modification elements of the tooth flank shape. The design support device 20 includes a gear specification acquisition unit 22 for acquiring the gear specifications from the storage device 21, a tool specification acquisition unit 23 for acquiring the tool specifications from the storage device 21, a Sollzahnprofilrichtungmodifikationsbetragerlangungseinheit 24 for acquiring the target tooth profile direction modification amount from the storage device 21, and a Sollzahnflankenlinienrichtungmodifikationsbetragerlangungseinheit 25 for acquiring the target tooth flank line direction modification amount from the storage device 21.A provisional designing unit 26 acquires the gear specifications from the gear specification acquiring unit 22, acquires the tool specifications from the tool specification acquiring unit 23, and acquires the target tooth profile direction modification amount from the Sollzahnprofilrichtungmodifikationsbetragerlangungseinheit 24.A correction amount determination unit 27 acquires the target tooth flank line direction modification amount from the target target tooth flank line direction modification amount acquisition unit 25. the correction amount determination unit 27 determines a correction amount of the machining control element during the machining operation based on the target tooth flank line direction modification amount acquisition unit 25. the machining control element has at least one of the axis intersection angle α, the offset angle γ indicating the position of the gear machining tool T in the circumferential direction of the workpiece, the distance D between the central axis of the workpiece and the central axis of the gear machining tool T, and a relative rotational speed between the workpiece and the gear machining tool T.A first tooth flank shape calculation unit 28 acquires the preliminarily designed tool cutting shape of the gear machining tool T from the preliminary design unit 26 and acquires the correction amount of the machining control element from the correction amount determination unit 27.A first target deviation calculation unit 29 acquires the first tooth flank shape from the first tooth flank shape calculation unit 28, and acquires a target tooth flank shape included in the gear specifications from the gear specification acquisition unit 22. The first target deviation calculation unit 29 compares the calculated first tooth flank shape with the target tooth flank shape, and calculates a first target deviation of the tooth flank shape in the tooth profile direction.A full design unit 30 acquires the first target deviation from the first target deviation calculation unit 29 and acquires the target tooth profile direction modification amount from the Sollzahnprofilrichtungsmodifikationsbetragerlangungseinheit 24.A second tooth flank shape calculation unit 31 acquires the fully designed tool edge shape from the full design unit 30 and acquires the correction amount of the machining control element from the correction amount determination unit 27.A second target deviation calculation unit 32 acquires the calculated second tooth flank shape from the second tooth flank shape calculation unit 31 and acquires the target tooth flank shape included in the gear specifications from the gear specification acquisition unit 22. The second tooth flank shape calculation unit 31 compares the calculated second tooth flank shape with the target tooth flank shape and calculates a second target deviation of the second tooth flank shape.A redesign unit 33 acquires the target tooth profile direction modification amount from the Sollzahnprofilrichtungmodifikationsbetragerlangungseinheit 24, acquires the target tooth flank line direction modification amount from the Sollzahnflankenlinienrichtungmodifikationsbetragerlangungseinheit 25, and acquires the second target deviation from the second target deviation calculation unit 32. the redesign unit 33 re-designs the shape of the tool blade based on at least one of the target tooth profile direction modification amount and the target tooth flank line direction modification amount and a second target deviation correction amount to reduce the second target deviation.A correction amount re-determination unit 34 acquires the target tooth profile direction modification amount from the Sollzahnprofilrichtungmodifikationsbetragerlangungseinheit 24, acquires the target tooth flank line direction modification amount from the Sollzahnflankenlinienrichtungmodifikationsbetragerlangungseinheit 25, and acquires the second target deviation from the second target deviation calculation unit 32.The design support device of the present embodiment may have both the redesign unit 33 and the correction amount re-determination unit 34, or only one of them.8. Operation of Design Support Device 20 (Design Method) (1) Main RoutineNext, the operation of the design support device 20 and the design method according to the present embodiment will be described. As is apparent from FIG. 20, upon activation of the design support device 20, a preliminary design process is performed to preliminarily design the tool-cutting shape of the gear machining tool T (S 1: preliminary design step). Next, a correction amount determination process is performed to determine the correction amount of the machining control element during the gear machining operation (S 2: correction amount determination step). Next, a complete design process is performed to completely design the tool-cutting shape of the gear machining tool T (S 3: complete design step).In order for the gear to be formed by machining a workpiece using the gear machining tool T having the tool edge shape determined by executing the full design process, a second target deviation calculation process is executed to calculate the second target deviation of the second tooth flank shape formed on the gear by comparing the second tooth flank shape with the target tooth flank shape included in the gear specifications (S 4: second target deviation calculation step). Next, a redesign process is performed to redesign the shape of the tool blade based on the second target deviation (S 5: redesign step). A correction amount re-determination process is performed to re-determine the correction amount of the machining control element based on the second target deviation (S 6: correction amount re-determination step). The order of the redesign process (S 5) and the correction amount re-determination process (S 6) is not limited. Both the redesign process (S 5) and the correction amount re-determination process (S 6) may be performed, or only one of them may be performed.(2) Preliminary Design ProcessAs is apparent from FIG. 21, when the preliminary design process is performed, the gear specification acquisition unit 22 acquires the gear specifications from the storage device 21 (S 11: gear specification acquisition step). The gear specifications contain information about the shape, material, etc. of the gear teeth to be machined on the workpiece. Next, the tool specification acquisition unit 23 acquires the tool specifications from the storage device 21 (S 12: tool specification acquisition step). The tool specifications include information on the shape, material, etc. of the gear machining tool T. Next, the Sollzahnprofilrichtungmodifikationsbetragerlangungseinheit 24 acquires the target tooth profile direction modification amount from the storage device 21 (S 13: target modification amount acquisition step). Next, the provisional design unit 26 designs the tool cutting shape of the gear machining tool T on the basis of the gear specifications, the tool specifications, and the target tooth profile direction modification amount (S 14: provisional design step). The tool-cutting shape of the gear machining tool T can be modified by the full design process described later. Therefore, the shape of the tool blade of the gear machining tool T is preliminarily designed.In the above-described manner, the provisional design process for the shape of the tool blade is completed.(3) Correction Amount Determination ProcessNext, the correction amount determination process (S 2) is performed as shown in FIG. 22. The gear machining simulation is performed to calculate a plurality of tooth flank shapes when the Y axis, which is one of the machining control elements, is changed (S 21: tooth flank shape calculation step). Next, the correlation between the amount of change ΔY in the Y axis and each modification element is calculated based on the deviation between the tooth flank shape of the gear calculated by the gear machining simulation and the reference tooth flank shape (S 22: correlation calculation step).Next, the gear machining simulation is performed to calculate a plurality of tooth flank shapes when the Cw axis, which is one of the machining control elements, is changed (S 23: tooth flank shape calculation step). Next, the correlation between the change amount ΔCw in the Cw axis and each modification element based on the deviation between the tooth flank shape calculated by the gear machining simulation and the reference tooth flank shape is calculated (S 24: correlation calculation step).Next, the gear machining simulation is performed to calculate a plurality of tooth flank shapes when the B axis, which is one of the machining control elements, is changed (S 25: tooth flank shape calculation step). Next, the correlation between the amount of change ΔY in the B axis and each modification element is calculated based on the deviation between the tooth flank shape of the gear calculated by the gear machining simulation and the reference tooth flank shape (S 26: correlation calculation step). The order of calculating the correlations of the Y-axis, the Cw-axis, and the B-axis may be changed as appropriate.Next, the correction amount determination unit 27 calculates a correction amount ΔYa in the Y axis (S 27: correction amount calculation step). For example, the correction amount determination unit 27 calculates the correction amount ΔYa in the Y axis based on a target crowning modification amount and the correlation between the change amount ΔY in the Y axis and the crowning modification amount Mc (upper schematic diagram in FIG. 15 ). The amount of change ΔY in the Y axis when the crowning modification amount Mc in FIG. 15 reaches the target modification amount is set as the correction amount ΔYa in the Y axis.Next, the correction amount determination unit 27 calculates a correction amount ΔBa in the B axis (S 28: correction amount calculation step). For example, the correction amount determination unit 27 calculates the correction amount ΔBa in the B axis based on a target bias modification amount, the change amount ΔB in the B axis, and the bias modification amount Mb (middle graph in FIG. 16 ), and the bias modification amount Mb when the correction amount ΔYa in the Y axis is set (middle graph in FIG. 15 ). For example, the bias modification amount Mb in FIG. 16 is determined such that the sum of the bias modification amount Mb when the correction amount ΔYa is set in the Y axis (intermediate schematic diagram in FIG. 15 ) and the bias modification amount Mb in FIG. 16 corresponds to the target modification amount. The amount of change ΔB in the B axis when the bias modification amount Mb is determined in FIG. 16 is set as the correction amount ΔBa in the B axis.Next, the correction amount determination unit 27 calculates a correction amount ΔCwa in the Cw axis (S 29: correction amount calculation step). For example, the correction amount determination unit 27 calculates the correction amount ΔCwa in the Cw axis based on a Sollzahnflankenlinienneigungsmodifikationsbetrag the change amount ΔCw in the Cw axis, and the tooth trace inclination modification amount Mh (lower schematic diagram in FIG. 17 ), the tooth trace inclination modification amount Mh when the correction amount ΔYa is set in the Y axis (lower schematic diagram in FIG. 15 ), and the tooth trace inclination modification amount Mh when the correction amount ΔBa is set in the B axis (lower schematic diagram in FIG. 16 ). For example, the tooth trace inclination modification amount Mh in FIG. 17 is determined such that the sum of the tooth trace inclination modification amount Mh when the correction amount ΔYa is set in the Y axis (lower schematic diagram in FIG. 15 ), the tooth trace inclination modification amount Mh when the correction amount ΔBa is set in the B axis (lower schematic diagram in FIG. 16 ), and the tooth trace inclination modification amount Mh in FIG. 17 matches the target modification amount. The change amount ΔCw in the Cw axis when the tooth trace inclination modification amount Mh is determined in FIG. 17 is set as the correction amount ΔCwa in the Cw axis.Next, the correction amount determination unit 27 calculates the crowning, biasing, and tooth flank line inclination modification amounts Mc', Mb', and Mh' (S 30: modification amount calculation step). The modification amounts Mc', Mb', and Mh' of the modification elements are calculated based on the correction amount ΔYa in the Y axis, the correction amount ΔBa in the B axis, the correction amount ΔCwa in the Cw axis, and the correlations. For example, the crowning modification amount Mc' is calculated based on the sum of the crowning modification amount Mc when the correction amount ΔYa is set in the Y axis (upper diagram in FIG. 15 ), the crowning modification amount Mc when the correction amount ΔBa is set in the B axis (upper diagram in FIG. 16 ), and the crowning modification amount Mc when the correction amount ΔCwa is set in the Cw axis (upper diagram in FIG. 17 ). The same is applied to the bias and tooth flank line inclination modification amounts Mb' and Mh'.Next, the correction amount determination unit 27 determines whether the crowning, biasing, and tooth flank line inclination modification amounts Mc', Mb', and Mh' approximately correspond to the respective target modification amounts (S 31: determination step). When the modification amounts Mc', Mb', and Mh' do not approximately correspond to the respective target modification amounts (S 31: N), the correction amount determination unit 27 returns to step S 27 and repeats the above process. For example, when the crowning modification amount Mc' deviates from the target modification amount, the correction amounts ΔYa, ΔBa, and ΔCwa of the modification elements are calculated so that the modification can be additionally made for the modification amount.As described above, the correction amount determination unit 27 calculates, in this order, the correction amount ΔYa in the Y axis, the correction amount ΔBa in the B axis, and the correction amount ΔCwa in the Cw axis. This is because, as can be seen from FIGS. 15 to 17, the changes of the modification amounts Mc, Mb, and Mh of the modification elements are smaller in the order of the Y axis, the B axis, and the Cw axis. That is, the B axis is less affected by the Y axis, and the Cw axis is less affected by the Y axis and the B axis. From this relationship, it is understood that the modification amounts Mc', Mb', and Mh' of the modification elements quickly come near the respective target modification amounts even in a simple calculation. That is, the number of repetitions of steps S 27 to S 31 can be reduced in the determination of the correction amounts ΔYa, ΔBa, and ΔCwa in the Y axis, the B axis, and the Cw axis.When the modification amounts Mc', Mb', and Mh' approximately correspond to the respective target adjustment amounts in S 31 (S 31: Y), the correction amount determination unit 27 determines the calculated correction amounts ΔYa, ΔBa, and ΔCwa in the Y axis, the B axis, and the Cw axis, which are the machining control elements (S 32: correction amount determination step). Therefore, the correction amounts ΔYa, ΔBa, and ΔCwa of the modification elements can be calculated with very simple calculation. The simple calculation described herein is a calculation that is simpler than the calculation by the gear machining simulation.(4) Full Design ProcessNext, as shown in FIG. 23, the first tooth flank shape calculation unit 28 calculates the first tooth flank shape of the gear by the gear machining simulation using the correction amounts ΔYa, ΔBa, and ΔCwa in the Y axis, the B axis, and the Cw axis, which are the machining control units determined by the correction amount determination unit 27 (S 33: first tooth flank shape calculation step). The first target deviation calculation unit 29 acquires the calculated first tooth flank shape (S 34: first tooth flank former acquisition step). The first target deviation calculation unit 29 compares the first tooth flank shape with the target tooth flank shape, and calculates the first target deviation of the first tooth flank shape in the tooth profile direction (S 35: first target deviation calculation step). The first target deviation is a deviation of at least one of the pressure angle and the tooth profile roundness.As shown in FIG. 24, the first target deviation is calculated based on the shape of the tooth flank Gf in a cross section PA perpendicular to the axis at a position at the center of the gear G in a tooth width direction Wd.Next, the full design unit 30 acquires the target tooth profile direction modification amount from the storage device 21 (S 36: target modification amount acquisition step). The full design unit 30 calculates the first target deviation correction amount to reduce the first target deviation calculated by the first tooth flank shape calculation unit 28 (S 37: first target deviation correction amount calculation step). The full design unit 30 fully designs the tool-edge shape of the gear machining tool T by modifying the tool-edge shape of the gear machining tool T toward the tooth profile based on the target tooth-profile direction modification amount and the first target deviation correction amount (S 38: full design step).(5) Second Target Deviation Calculation MethodNext, as can be seen from FIG. 25, the second tooth flank shape calculation unit 31 acquires the correction amounts ΔYa, ΔBa, and ΔCwa in the Y axis, the B axis, and the Cw axis, which are the machining control units determined by the correction amount determination unit 27 (S 41: correction amount acquisition step), and acquires the tool cutting shape of the gear machining tool T completely designed by the full design unit 30 (S 42: tool cutting shape acquisition step). The second tooth flank shape calculation unit 31 calculates the second tooth flank shape of the gear by the gear machining simulation based on the correction amounts of the machining control units and the fully designed tool blade shape (S 43: second tooth flank shape calculation step).The second target deviation calculation unit 32 acquires the target tooth flank shape included in the gear specifications from the storage device 21 (S 44: step of acquiring the target tooth flank shape). The second target deviation calculation unit 32 compares the second tooth flank shape with the target tooth flank shape and calculates the second target deviation of the second tooth flank shape (S 45: second target deviation calculation step). The second desired deviation has either a deviation in the direction of the tooth profile or a deviation in the direction of the tooth flank line, or both.(6) Redesign ProcessThe redesign unit 33 re-designs the tool cutting shape of the gear machining tool T by modifying the tool cutting shape when the second target deviation occurs in the tooth profile direction modifying element. As is apparent from FIG. 26, the redesign unit 33 acquires the target tooth profile direction modification amount from the storage device 21 (S 51: target modification amount acquisition step). The redesign unit 33 calculates the second target deviation correction amount for reducing the second target deviation for the tooth profile direction modification element (S 52: second target deviation calculation step). The redesign unit 33 re-designs the tool-cutting shape of the gear machining tool T by modifying the tool-cutting shape in the tooth profile direction based on the target tooth profile direction modification amount and the second target deviation correction amount (S 53: tool-cutting shape redesign step).(7) Correction amount re-determination processThe correction amount re-determination unit 34 re-determines the correction amount of the control unit for machining when the second target deviation occurs in the tooth trace direction modification element. As is apparent from FIG. 27, the correction amount re-determination unit 34 acquires the target tooth track direction modification amount from the storage device 21 (S 61: step of acquiring the target modification amount). The correction amount re-determination unit 34 calculates the second target deviation correction amount for reducing the second target deviation for the tooth flank line direction modification element (S 62: second target deviation calculation step). The correction amount re-determination unit 34 re-determines the correction amount of the control unit for the processing based on the Sollzahnflankenlinienrichtungsmodifkiationsbetrag and the second target deviation correction amount (S 63: correction amount re-determination step). In the above-described manner, all the processes are completed.9. Example:Next, an example in which the present embodiment is applied to a specific gear machining tool T will be described. Table 1 shows the target tooth profile direction modification amounts and the target tooth flank line direction modification amounts of the gear machining tool T according to the present example. [Table 1] (Table 1) (Table 1)Angle of Intervention Modification Amount [μm]0.00.6-0.6Tooth Profile Roundness Modification Amount [μm]0.00.2-0.2Tooth Tooth Trace Inclination Modification Amount [μm]5.00.0-Crown modification amount [μm]5.00.0-Bias modification amount [μm]10.00.0-In the present example, the amount of the meshing angle modification and the amount of the tooth profile roundness modification, which are the target tooth profile direction modification elements, are set to 0.0 μm. The tooth flank line inclination modification amount, the crowning modification amount, and the bias modification amount, which are the target tooth flank line direction modification elements, are set to 5.0 μm, 5.0 μm, and 10.0 μm, respectively. The tool cutting shape provisional design process is performed on the gear machining tool T according to the present example to preliminarily design the tool cutting shape (S 1 in FIG. 20 ).Next, the correction amount determination process is performed based on the target tooth flank line direction modification amount to determine the correction amount of the machining control element during the operation of machining (S 2 in FIG. 20 ).Next, the first tooth flank shape of the gear is calculated based on the correction amount of the machining control member and the preliminarily designed tool cutting shape (S 33 in FIG. 23 ). The calculated first tooth flank shape is compared with the target tooth flank shape, and the first target deviation of the first tooth flank shape in the tooth profile direction is calculated (S 35 in FIG. 23 ).As is apparent from Table 1, in the present example, the first target deviations occurred in the target tooth profile direction modification elements. In particular, the first setpoint deviation of the engagement angle is 0.6 μm and the first setpoint deviation of the tooth profile roundness is 0.2 μm. The first target deviations for the tooth flank inclination, the crowning and the prestress, which relate to the modification elements for those for the target tooth flank direction, are 0.0 μm.When the machining control element is corrected during the machining operation based on the modification amount of the target tooth flank direction, by the correction, the movement path of the gear machining tool T during the machining operation changes. Thus, the shape to be removed from the workpiece by the gear machining tool T changes. As a result, it is considered that the first target deviation occurs between the calculated first tooth flank shape and the target tooth flank shape in the tooth profile direction.Next, the first target deviation correction amounts for reducing the first target deviations are calculated for the engagement angle and the tooth profile roundness (S 37 in FIG. 23 ).For the engagement angle, the target tooth profile direction modification amount is 0.0 μm and the first target deviation is 0.6 μm. Therefore, the first target deviation correction amount is calculated to be -0.6 μm. For the tooth profile roundness, the target tooth profile direction modification amount is 0.0 μm and the first target deviation is 0.2 μm. Therefore, the first target deviation correction amount is calculated to be -0.2 μm.Next, the tool-edge shape of the gear machining tool T is fully designed based on the target tooth profile direction modification amounts and the first target deviation correction amounts (S 38 in FIG. 23 ).Next, the second tooth flank shape of the gear is calculated based on the correction amount of the machining control member and the fully designed tool cutting shape of the gear machining tool T (S 43 in FIG. 25 ). The calculated second tooth flank shape is compared with the target tooth flank shape, and the second target deviation of the second tooth flank shape is calculated (S 45 in FIG. 25 ). The second desired deviation can have both a deviation in the direction of the tooth profile and a deviation in the direction of the tooth track or only one of them.As is apparent from Table 1, no second target deviation occurred in the present example. Specifically, the first target value deviation of the engagement angle and the second target value deviation of the tooth profile roundness is 0.0 μm, and the second target value deviations of the tooth flank inclination, crowning, and biasing are 0.0 μm.10. Operations and Effects of the Present EmbodimentIn the present embodiment, no second set value deviation occurred. Therefore, the tool-edge shape is not re-designed in the redesign process for the tool-edge shape (S 5 in FIG. 20 ), and the correction amount is not re-determined in the correction amount re-determination process (S 6 in FIG. 20 ).In the present example, the tool-cutting shape of the gear machining tool T is entirely designed on the basis of the first target deviation correction amount to reduce the first target deviation that has occurred by correcting the machining control element during the machining operation on the basis of the Sollzahnflankenneigungsrichtungsmodifikationsbetrags. Therefore, it is possible to suppress the occurrence of the tooth flank shape deviation of the gear in the tooth profile direction even when the machining control element is corrected based on the modification amount of the target tooth flank line inclination direction.In the present embodiment, the second tooth flank shape of the gear is calculated based on the correction amount of the machining control element and the fully designed tool blade shape, and the second target deviation of the calculated second tooth flank shape is calculated by comparing the second tooth flank shape with the target tooth flank shape. Therefore, the deviation can be calculated as the second target deviation even if an unexpected deviation has occurred in the second tooth flank shape of the gear machined by the fully designed gear machining tool T due to the modification from the preliminarily designed tool cutting shape to the fully designed tool cutting shape. Thus, it is possible to take measures even if the unexpected deviation has occurred.In the present embodiment, when the second target deviation has occurred, the tool cutting shape is newly designed or the correction amount of the machining control element is newly determined based on the second target deviation correction amount to reduce the second target deviation. Therefore, it is possible to suppress the occurrence of the deviation in the tooth flank shape of the gear when the preliminarily designed tool cutting shape is modified into the fully designed tool cutting shape.(Second Embodiment)Next, a second embodiment will be described with reference to FIG. 28. As is apparent from FIG. 28, in the present embodiment, in the correction amount determination process (S 2), the correction amount is determined based on the shape of the tooth flank Gf in the cross section PA perpendicular to the axis at an arbitrary position on the gear tooth G in the direction of the tooth width Wd.In the following description, the same elements as in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.According to the present embodiment, for example, the first target deviation may be calculated based on the cross section perpendicular to the axis at a location particularly affected by the deviation at the gear tooth G in the tooth width Wd direction. Thus, it is possible to improve the accuracy of the calculation of the first target deviation.(Third Embodiment)Next, a third embodiment will be described with reference to FIG. 29. As is apparent from FIG. 29, in the present embodiment, the first target deviation is calculated based on the shapes of the tooth flank Gf in cross sections PA 1 and PA 2 perpendicular to the axis at a plurality of locations (two locations in the present embodiment) on the gear tooth G in the direction of the tooth width Wd (S 35 in FIG. 23 ). In the present embodiment, the first target deviation may be calculated based on an average value of the deviations in the cross sections PA 1 and PA 2 perpendicular to the axis at the two locations, for example. According to the present embodiment, it is possible to improve the accuracy of calculation of the first target deviation based on the cross sections PA 1 and PA 2 perpendicular to the axis at the plurality of locations.(Fourth Embodiment)Next, a fourth embodiment will be described with reference to FIG. 30. As is apparent from FIG. 30, in the present embodiment, the first target deviation is calculated from deviations in the direction of the tooth profile calculated over the entire range of the gear G in the direction of the tooth width Wd (S 35 in FIG. 23 ). In the present embodiment, the first target deviation may be calculated based on, for example, an average value of the deviations over the entire range of the gear G in the direction of the tooth width Wd. According to the present embodiment, it is possible to improve the accuracy of calculation of the first target deviation based on the entire range of the gear G in the direction of the tooth width Wd.(Fifth Embodiment)Next, a fifth embodiment will be described with reference to FIG. 31. As is apparent from FIG. 31, in the present embodiment, the first target deviation is calculated from deviations in the tooth profile direction calculated over a partially continuous range A of the gear G in the tooth width direction WD (S 35 in FIG. 23 ). In the present embodiment, the first target deviation may be based on, for example, the range A particularly affected by the deviation at the gear tooth G in the tooth width Wd. Thus, it is possible to improve the accuracy of the calculation of the first target deviation.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedJP 2021 - 11 011

[0003] JP 2021-11 011 A [0003, 0004, 0041]JP 2017-144 502 A

[0032]

Claims

A method for designing a gear machining tool (T) configured to machine teeth (G) of a gear on a workpiece (W) by moving the workpiece and the gear machining tool relative to each other while the gear machining tool and the workpiece are synchronously rotated in a state in which an axis parallel to a central axis (RT) of the gear machining tool has a predetermined axis intersection angle (a) with respect to a central axis (RW) of the workpiece, the method comprising: a step (S1) of obtaining gear specifications that are specifications of the gear, obtaining tool specifications that are specifications of the gear machining tool, obtaining a target tooth profile direction modification amount, which is a target value of a tooth profile direction modification element of a tooth flank shape of the gear, and preliminarily design a tool blade shape of the gear machining tool based on the gear specifications, the tool specifications, and the target tooth profile direction modification amount; a step (S 2) of obtaining a target tooth flank line direction modification amount which is a target value of a tooth flank line modification element of the tooth flank shape, and determining a correction amount of a machining control element based on the target tooth flank line direction modification amount during a machining operation; a step (S 33) of calculating a first tooth flank shape of the gear based on the correction amount of the machining control element and the preliminarily designed tool blade shape; a step (S 35) of comparing the calculated first tooth flank shape with a target tooth flank shape specified in the wheel specifications and calculating a first target deviation of the first tooth flank shape in the tooth profile direction; and a step (S 38) of fully designing the tool blade shape based on the target tooth profile direction modification amount and a first target deviation correction amount for reducing the first target deviation.The method for designing a gear machining tool according to claim 1, further comprising: a step (S43) of calculating a second tooth flank shape of the gear based on the correction amount of the machining control element and the fully designed tool edge shape; and a step (S45) of comparing the calculated second tooth flank shape with the target tooth flank shape indicated in the specifications of the gear and calculating a second target deviation of the second tooth flank shape.The method for designing a gear machining tool according to claim 2, further comprising a step (S53, S63) of redesigning the shape of the tool blade based on at least one of the target tooth profile direction modification amount and the target tooth flank line direction modification amount and a second target deviation correction amount for reducing the second target deviation or re-determining the correction amount of the machining control element.The method for designing a gear machining tool according to claim 1, wherein the first target deviation in the tooth profile direction is calculated in a cross section (PA) perpendicular to an axis at a location on the gear in a tooth width direction (Wd).The method for designing a gear machining tool according to claim 4, wherein the first target deviation in the tooth profile direction is calculated in a cross section perpendicular to the axis at a location at a center in the tooth width direction.The method for designing a gear machining tool according to claim 1, wherein the first target deviation is calculated from deviations in the tooth profile direction calculated in cross sections (PA1, PA2) perpendicular to an axis at a plurality of locations on the gear in a tooth width direction.The method for designing a gear machining tool according to claim 1, wherein the first target deviation is calculated from deviations in the tooth profile direction calculated over an entire range of the gear in a tooth width direction.The method for designing a gear machining tool according to claim 1, wherein the first target deviation is calculated from deviations in the tooth profile direction calculated over a partial region (A) of the gear in a tooth width direction.The method for designing a gear machining tool according to any one of claims 1 to 8, wherein the tooth profile direction modifying member has at least one of an engagement angle and a tooth profile roundness, and the tooth flank line direction modifying member has at least one of a crowning, a preload, and a tooth flank line inclination.The method for designing a gear machining tool according to any one of claims 1 to 8, wherein the machining control element to be corrected has at least one of: the axis cut angle (a); an offset angle (γ) indicating a position of the gear machining tool in a direction along the circumference of the workpiece; a center distance (D) between the center axis of the workpiece and the center axis of the gear machining tool; and a relative rotational speed between the workpiece and the gear machining tool.A design support device (20) for a gear machining device (T) configured to machine teeth (G) of a gear on a workpiece (W) by moving the workpiece and the gear machining device relative to each other while the gear machining device and the workpiece are synchronously rotated in a state in which an axis parallel to a central axis (RT) of the gear machining device has a predetermined axis intersection angle (α) with respect to a central axis (RW) of the workpiece, the design support device comprising: a gear specification acquisition unit (22) configured to acquire gear specifications that are specifications of the gear; a tool specification acquisition unit (23) configured to acquire tool specifications that are specifications of the gear machining tool; Sollzahnprofilrichtungmodifikationsbetragerlangungseinheit (24) configured to acquire an amount of modification of the direction of the target tooth target tooth profile direction modification amount that is a target value of a tooth profile direction modification element of a tooth flank shape of the gear; a PROVISIONALr DESIGN UNIT (26) configured to preliminarily design a tool cutting shape of the gear machining tool based on the gear specifications, the tool specifications, and the target tooth profile direction modification amount; a Sollzahnflankenlinienrichtungmodifikationsbetragerlangungseinheit (25) configured to acquire a target tooth flank line direction modification amount that is a target value of a tooth flank line direction modification element of the tooth flank shape; a correction amount determination unit (27) configured to determine a correction amount of a machining control unit during machining operation based on the target tooth flank line direction modification amount; a first tooth flank shape calculation unit (28) configured to calculate a first tooth flank shape of the gear based on the correction amount of the machining control unit and the preliminarily designed tool edge shape; a first target deviation calculation unit (29) configured to compare the calculated first tooth flank shape with a target tooth flank shape indicated in the specifications of the gear and calculate a first target deviation of the tooth flank shape in the tooth profile direction; and a full design unit (30) configured to fully design the shape of the tool blade on the basis of the target tooth profile direction modification amount and a first target deviation correction amount for reducing the first target deviation.The design support device for a gear machining tool according to claim 11, further comprising: a second tooth flank shape calculation unit (31) configured to calculate a second tooth flank shape of the gear based on the correction amount of the machining control unit and the fully designed tool edge shape; and a second target deviation calculation unit (32) configured to compare the calculated second tooth flank shape with the target tooth flank shape specified in the specifications of the gear and calculate a second target deviation of the second tooth flank shape.The design support device for a gear machining tool according to claim 12, further comprising a redesign unit (33) configured to redesign the tool cutting edge shape, or a correction amount redesign unit (34) configured to redefine the correction amount of the machining control element based on at least one of the target tooth profile direction modification amount and the target tooth flank line direction modification amount, and a second target deviation correction amount for reducing the second target deviation.

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