Gear machining equipment and machining condition determining device

Abstract

The present invention provides a gear machining apparatus and a machining condition determination device that can shorten the overall machining time when performing tooth profile machining and chamfering machining. The control device (100) of the gear machining apparatus (1) includes: a first chamfering machining control unit (101) for machining a chamfer (62, 72, 82) at one axial end of the tooth profile (61, 71, 81) by moving a hob (T) relative to the workpiece (W) axially and radially relative to the workpiece (W); a tooth profile machining control unit (102) for machining the tooth profile (61, 71, 81) after chamfering at one axial end; and a second chamfering machining control unit (103) for machining the other axial end of the tooth profile by moving the hob (T) relative to the workpiece (W) axially and radially relative to the workpiece after machining the tooth profile.

Description

Technical Field

[0001] This invention relates to a gear machining apparatus and a machining condition determination device. Background Technology

[0002] Patent document 1 describes a technique for chamfering the corners of the axial ends of the tooth profile after tooth profile machining by a hob.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2013-212551

[0004] Chamfering operations using shaping tools are sometimes performed on a dedicated machine, different from the machining unit equipped with a hob. In this case, a dedicated chamfering machine must be installed, increasing equipment costs. Furthermore, the workpiece with the teeth machined by the hob must be transported from the machining unit equipped with the hob to the machining unit equipped with the shaping tool, thus lengthening the overall processing time.

[0005] Alternatively, general-purpose equipment such as machining centers can be used to perform hob-based tooth profile machining and chamfering based on forming tools. In this case, hob-based tooth profile machining is performed in the machining apparatus, followed by a tool change from hob to forming tool, and then chamfering based on the forming tool is performed. Therefore, the tool change is required, and the overall machining time is correspondingly longer. Summary of the Invention

[0006] The object of this invention is to provide a gear machining apparatus that can shorten the overall machining time when performing tooth profile machining and chamfering. Another object of this invention is to provide a machining condition determining apparatus for determining the machining conditions in a gear machining method performed by the gear machining apparatus.

[0007] (1. Gear machining device)

[0008] A gear machining apparatus includes a hob for machining tooth profiles on a workpiece; and a control device for synchronously rotating and moving the hob relative to the workpiece. The control device includes: a first chamfering control unit that moves the hob relative to the workpiece axially and radially relative to the workpiece to perform chamfering at one axial end of the tooth profile; a tooth profile machining control unit that, following the chamfering at one axial end of the tooth profile, moves the hob relative to the workpiece axially to machine the tooth profile; and a second chamfering control unit that, following the tooth profile machining, moves the hob relative to the workpiece axially and radially relative to the workpiece to perform chamfering at the other axial end of the tooth profile.

[0009] According to the gear machining apparatus described above, a hob is used for chamfering and tooth profile machining. Specifically, by moving the hob axially toward the workpiece once, chamfering at one end of the axial direction, tooth profile machining, and chamfering at the other end of the axial direction can be performed sequentially.

[0010] More specifically, the chamfering at one axial end is performed by adding a radial motion while moving the hob axially toward the workpiece. Following this chamfering, the hob is moved axially toward the workpiece, thereby machining the tooth profile. That is, the chamfering at one axial end is performed before machining the tooth profile. Then, after machining the tooth profile, the chamfering at the other axial end is performed. The chamfering at the other axial end is performed by moving the hob axially toward the workpiece and radially toward the workpiece.

[0011] In other words, the chamfering at one end of the axial direction, the machining of the tooth profile, and the chamfering at the other end of the axial direction are all performed through a series of actions by a hob. Therefore, no workpiece transport or tool changing is required for chamfering. Consequently, the overall machining time for both tooth profile machining and chamfering is reduced.

[0012] (2. Processing condition determination device)

[0013] The machining condition determining device is a device that determines the machining conditions in a gear machining method that uses a hob to machine tooth profiles on a workpiece. The gear machining method includes: a first chamfering step, in which the hob is moved relative to the workpiece axially and radially to perform chamfering at one axial end of the tooth profile; a tooth profile machining step, following the chamfering at one axial end of the tooth profile, in which the hob is moved relative to the workpiece axially to machine the tooth profile; and a second chamfering step, following the tooth profile machining, in which the hob is moved relative to the workpiece axially and radially to perform chamfering at the other axial end of the tooth profile.

[0014] For each of the chamfering processes at one axial end of the aforementioned tooth profile and the chamfering process at the other axial end of the aforementioned tooth profile, the chamfer shape is simulated under various processing conditions related to the relative movement trajectory of the hob relative to the workpiece, thereby determining a processing condition related to the relative movement trajectory of the hob relative to the workpiece in which the chamfer shape satisfies the specified allowable conditions.

[0015] When performing chamfering, it is not easy to derive the relative movement trajectory of the hob relative to the workpiece. This is especially true when the gear teeth and hob cutting edges have a torsion angle, or when the gear and hob are at a crossing angle. Due to these situations, it is difficult to determine the relationship between the relative movement trajectory of the hob and the chamfer shape.

[0016] Furthermore, as elements of the chamfer shape, there are various target shapes, such as the chamfer angle of the corner between the axial edge of the tooth tip and the tooth thickness direction edge of the tooth shape, the axial chamfer length of the corner between the axial edge of the tooth tip and the tooth thickness direction edge of the tooth shape, the chamfer angle of the corner between the tooth root of the axial section of the workpiece and the axial end face of the tooth shape, and the axial chamfer length of the corner between the tooth root of the axial section of the workpiece and the axial end face of the tooth shape.

[0017] Therefore, the relative movement trajectory of the hob cannot be simply derived based on, for example, the chamfer angle and the outer diameter of the hob. Therefore, simulation is performed to determine a machining condition related to the relative movement trajectory of the hob relative to the workpiece, where the chamfer shape meets specified allowable conditions. As a result, it is possible to determine the machining conditions that ensure the chamfer shape meets the specified allowable conditions. Attached Figure Description

[0018] Figure 1 This is a perspective view showing an example of a gear processing device.

[0019] Figure 2 It is a diagram showing the state of a workpiece being machined using a hob.

[0020] Figure 3 This is a partial 3D view of a gear.

[0021] Figure 4 This is a partial view taken from the axial direction of the gear.

[0022] Figure 5 From Figure 4 The diagram is viewed from the V direction, that is, from the radial outside of the gear.

[0023] Figure 6 yes Figure 4 The VI-VI sectional view, which is the axial sectional view of the gear.

[0024] Figure 7 This is a functional block diagram representing the control and drive devices of a gear processing device.

[0025] Figure 8 This is a flowchart illustrating the gear machining method.

[0026] Figure 9 It is a diagram showing the gear machining method, and it is also a diagram showing the positional relationship between the workpiece and the hob when the first chamfering process begins.

[0027] Figure 10 It is a diagram showing the gear machining method, and it is also a diagram showing the positional relationship between the workpiece and the hob when the first chamfering is completed and the tooth profile machining begins.

[0028] Figure 11 It is a diagram showing the gear machining method, and it is also a diagram showing the positional relationship between the workpiece and the hob when the tooth profile machining is completed and the second chamfering machining is started.

[0029] Figure 12 It is a diagram showing the gear machining method, and also a diagram showing the positional relationship between the workpiece and the hob after the second chamfering process is completed.

[0030] Figure 13 This is a functional block diagram representing the device that determines the processing conditions.

[0031] Figure 14 This is a flowchart illustrating the condition determination process performed by the processing condition determination device.

[0032] Explanation of reference numerals in the attached figures

[0033] 1: Gear machining device; T: Hob; W: Workpiece; 50: Tooth tip; 61: Tooth root (tooth profile); 71, 81: Tooth surface (tooth profile); 62, 72, 82: Chamfer at one axial end; 63, 73, 83: Chamfer at the other axial end; 91, 92: Axial end face; 100: Control device; 101: First chamfering machining control unit; 102: Tooth profile machining control unit; 103: Second chamfering machining control unit; 120: Machining condition determination device; 121: Parameter acquisition unit; 122: Simulation processing unit; 123: Judgment unit; 124: Parameter modification unit; G: Gear; L1: First separation distance (end position of the first chamfering machining operation); L2: Second separation distance (start position of the second chamfering machining operation). First perspective, The second angle, θb1: tooth root chamfer angle, θb2: tooth root chamfer angle, θt1: tooth tip chamfer angle, θt2: tooth tip chamfer angle Detailed Implementation

[0034] (1. Structure of gear machining device 1)

[0035] Reference Figure 1 Let me explain the gear machining apparatus 1. The gear machining apparatus 1 is a device that moves the hob T relative to the workpiece W, thereby creating a machined tooth profile on the workpiece W by means of the hob T.

[0036] In this example, the gear machining device 1 uses a general-purpose machine tool, such as a machining center. That is, the machining center is configured with interchangeable tools, capable of performing machining corresponding to the installed tools. For example, in addition to the hob T, interchangeable tools include gear cutting tools, end mills, milling tools, drills, turning tools, thread cutting tools, grinding tools, etc. Furthermore, in Figure 1 The tool changing device and tool magazine for storing tools are not shown in the diagram.

[0037] Furthermore, in this example, the machining center serving as gear machining device 1 is based on a horizontal machining center. However, gear machining device 1 can also utilize other structures such as vertical machining centers.

[0038] like Figure 1 As shown, the gear machining device 1, for example, has three mutually orthogonal straight-line axes (X-axis, Y-axis, and Z-axis) as drive shafts. Here, the direction of the rotation axis of the hob T (equal to the rotation axis of the tool spindle) is defined as the Z-axis direction, and the two axes orthogonal to the Z-axis direction are defined as the X-axis direction and the Y-axis direction. Figure 1 In this design, the horizontal direction is defined as the X-axis, and the vertical direction as the Y-axis. Furthermore, the gear machining apparatus 1 has two rotational axes (A-axis and B-axis) as drive shafts for changing the relative posture of the hob T and the workpiece W. Additionally, the gear machining apparatus 1 has a Ct-axis as a rotational axis for rotating the hob T.

[0039] That is, the gear machining device 1 is a 5-axis machining center capable of machining free-form surfaces (or a 6-axis machining center if the tool spindle (Ct axis) is considered). Here, the gear machining device 1 can also replace the structure with the A axis (rotation axis about the X axis in the reference state) and the B axis (rotation axis about the Y axis in the reference state), and can be set to have a Cw axis (rotation axis about the Z axis in the reference state) and the B axis, or it can be set to have an A axis and a Cw axis.

[0040] In the gear machining apparatus 1, the structure for relative movement between the hob T and the workpiece W can be appropriately selected. In this example, the gear machining apparatus 1 can move the hob T linearly along the Y-axis and Z-axis, move the workpiece W linearly along the X-axis, and rotate the workpiece W about the A-axis and the B-axis. Additionally, the hob T can rotate about the Ct-axis.

[0041] The gear processing apparatus 1 includes a base 10, a workpiece holding device 20, and a tool holding device 30. The base 10 is formed into an arbitrary shape, such as a roughly rectangular shape, and is mounted on the ground. The workpiece holding device 20 enables the workpiece W to move linearly relative to the base 10 along the X-axis and allows for rotation along the A-axis and B-axis. The workpiece holding device 20 mainly includes an X-axis moving worktable 21, a B-axis rotary table 22, and a workpiece spindle assembly 23.

[0042] The X-axis moving stage 21 is configured to move relative to the base 10 along the X-axis direction. Specifically, the base 10 is provided with a moving stage along the X-axis direction ( Figure 1 A pair of X-axis guide rails extending in the front-back direction; the X-axis moving worktable 21 is driven by a drive device such as a linear motor or ball screw mechanism (not shown), thereby moving in the X-axis direction while being guided by the pair of X-axis guide rails.

[0043] The B-axis rotary table 22 is disposed on the upper surface of the X-axis moving stage 21 and moves integrally with the X-axis moving stage 21 in the X-axis direction. Furthermore, the B-axis rotary table 22 is configured to rotate relative to the X-axis moving stage 21 along the B-axis. A rotary motor (not shown) is housed in the B-axis rotary table 22, and the B-axis rotary table 22 is driven by the rotary motor to rotate along the B-axis.

[0044] The workpiece spindle assembly 23 is mounted on the B-axis rotary table 22 and rotates along the B-axis integrally with the B-axis rotary table 22. The workpiece spindle assembly 23 supports the workpiece W so that it can rotate along the A-axis. In this example, the workpiece spindle assembly 23 cantileverly supports the workpiece W. The workpiece spindle assembly 23 includes a rotary motor (not shown) that rotates the workpiece W. With the above structure, the workpiece holding device 20 can move the workpiece W relative to the base 10 in the X-axis direction and can rotate along both the A-axis and B-axis.

[0045] The tool holding device 30 mainly includes a column 31, a saddle 32, and a tool spindle assembly 33. The column 31 is configured to move relative to the base 10 in the Z-axis direction. Specifically, the base 10 is provided with a Z-axis direction ( Figure 1 A pair of Z-axis guide rails extending in the left and right directions; the column 31 is driven by a drive device such as a linear motor or ball screw mechanism (not shown), thereby being guided by the pair of Z-axis guide rails and moving in the Z-axis direction.

[0046] The saddle 32 is disposed on the side of the workpiece W side of the column 31. Figure 1 The left side of the column 31, and a side surface parallel to a plane orthogonal to the Z-axis. A side surface along the Y-axis is provided on the side surface of the column 31. Figure 1 A pair of Y-axis guide rails extending in the vertical direction are provided. The saddle 32 is driven by a linear motor or ball screw mechanism (not shown) to move in the Y-axis direction.

[0047] The tool spindle assembly 33 is mounted on the saddle 32 and moves integrally with the saddle 32 in the Y-axis direction. The tool spindle assembly 33 supports the hob T so that it can rotate along the Ct axis. In this example, the tool spindle assembly 33 cantilever-supports the hob T. However, the tool spindle assembly 33 may also have a double-arm support structure for the hob T. The tool spindle assembly 33 includes a rotary motor (not shown) for rotating the hob T. Thus, the tool holding device 30 allows the hob T to move relative to the base 10 in the Y-axis and Z-axis directions and holds it so that it can rotate along the Ct axis.

[0048] (2. Description of the machining state of hob T)

[0049] Reference Figure 2 This illustrates the state when a machining tooth profile is created on the workpiece W using a hob T. For example, as... Figure 2 As shown, the hob T passes through the base end side ( Figure 2 The mounting portion (on the right side) is mounted on the tool spindle assembly 33 and cantilevered. Furthermore, the hob T has multiple cutting edges on its outer circumferential surface on the front end side (free end side). These multiple cutting edges are arranged discontinuously in a spiral pattern. The multiple cutting edges of the hob T are arranged in multiple turns. That is, the hob T has multiple rows of cutting edges in the axial direction. Figure 2 The diagram shows the case where the hob T has 5 to 6 cutting rows.

[0050] In tooth profile machining, the central axis of the hob T intersects the central axis of the workpiece W at an angle. This angle is formed by the axis parallel to the central axis of the workpiece W at the machining point, and the axis parallel to the central axis of the hob T at the machining point. In this example, the angle is shown as 90°, but it can also be any angle other than 90°. Furthermore, while the hob T rotates about its central axis and the workpiece W rotates synchronously about its central axis, the hob T is moved relative to the central axis of the workpiece W.

[0051] In this example, the hob T is positioned at the upper end of the workpiece W. That is, with the hob T positioned along the Y-axis, it is moved relative to the workpiece W along the X-axis and Z-axis, thereby achieving the aforementioned action. However, the machining position is not limited to the upper end of the workpiece W; it can also be set to other positions around the circumference of the workpiece W.

[0052] (3. Design shape of gear G)

[0053] Reference Figures 3-6 This section describes the design shape of gear G, which serves as the target shape for machining workpiece W; that is, the ideal shape of the machined gear G. Here, gear G is described using an external gear as an example, but internal gears can also be applied. Furthermore, for ease of explanation, while gear G is described as a gear without a torsion angle in this example, it can also be described as a gear with a torsion angle.

[0054] Gear G has a convex-concave tooth profile in the circumferential direction, that is, it has multiple convex teeth. Gear G has a front end face of the convex teeth, namely the tooth tip 50. There is a tooth groove between adjacent convex teeth in the circumferential direction. The tooth groove is formed by the tooth root 61, the tooth surface 71 as a meshing surface, and the tooth surface 81 as another meshing surface. The tooth surfaces 71 and 81 are formed, for example, by an involute curve. In addition, gear G has an end face 91 in one axial direction and an end face 92 in the other axial direction.

[0055] Furthermore, gear G has chamfers 62, 72, and 82 formed at one axial end of its tooth profile. Specifically, gear G has a chamfer 62 formed at the corner of the tooth root 61 and the end face 91 on one side of the axial direction, a chamfer 72 formed at the corner of one tooth surface 71 and the end face 91, and a chamfer 82 formed at the corner of the other tooth surface 81 and the end face 91.

[0056] Furthermore, gear G has chamfers 63, 73, and 83 formed at the other end of the tooth profile along the axial direction. Specifically, gear G has a chamfer 63 formed at the corner of the tooth root 61 and the end face 92 on the other side of the axial direction, a chamfer 73 formed at the corner of one tooth surface 71 and the end face 92, and a chamfer 83 formed at the corner of another tooth surface 81 and the end face 92.

[0057] like Figure 5 as well as Figure 6 As shown, the chamfering shape elements on one side of the axial direction include the tooth tip chamfer angle θt1, the tooth tip chamfer length Ct1, the tooth root chamfer angle θb1, and the tooth root chamfer length Cb1. Furthermore, the chamfering shape elements on the other side of the axial direction include the tooth tip chamfer angle θt2, the tooth tip chamfer length Ct2, the tooth root chamfer angle θb2, and the tooth root chamfer length Cb2.

[0058] The tooth tip chamfer angle θt1 is the chamfer angle at the corner of the tooth tip 50 in the tooth profile, between the axial edge and the tooth thickness edge (the edge extending along the tooth direction). The tooth tip chamfer length Ct1 is the axial chamfer length at the corner of the tooth tip 50 in the tooth profile, between the axial edge and the tooth thickness edge. The tooth root chamfer angle θb1 is the chamfer angle at the corner of the tooth root 61 and the axial end face 91 in the axial section of gear G (workpiece W). The tooth root chamfer length Cb1 is the axial chamfer length at the corner of the tooth root 61 and the axial end face 91 in the axial section of gear G (workpiece W). Here, the tooth tip chamfer length Ct1 and the tooth root chamfer length Cb1 are very small relative to the tooth width L.

[0059] The tooth tip chamfer angle θt2 is the chamfer angle at the corner of the tooth tip 50 in the tooth profile, between the edge on the opposite side of the axial direction and the edge in the tooth thickness direction. The tooth tip chamfer length Ct2 is the axial chamfer length at the corner of the tooth tip 50 in the tooth profile, between the edge on the opposite side of the axial direction and the edge in the tooth thickness direction. The tooth root chamfer angle θb2 is the chamfer angle at the corner of the tooth root 61 and the end face 92 on the opposite side of the axial direction in the axial section of gear G (workpiece W). The tooth root chamfer length Cb2 is the axial chamfer length at the corner of the tooth root 61 and the end face 92 on the opposite side of the axial direction in the axial section of gear G (workpiece W). Here, the tooth tip chamfer length Ct2 and the tooth root chamfer length Cb2 are very small relative to the tooth width L.

[0060] Furthermore, specific allowable conditions are set for each element of the chamfer shape. That is, in the machined workpiece W, if each element of the chamfer shape meets the specified allowable conditions, the workpiece W is a qualified product. In other words, the machining conditions are determined in a manner that satisfies the specified allowable conditions for each element of the chamfer shape.

[0061] (4. Structure of the control device 100 of the gear processing device 1)

[0062] Reference Figure 7 The structure of the control device 100 of the gear processing apparatus 1 will be explained below. The control device 100 consists of... Figure 1 Part of the gear machining device 1 shown, controlling Figure 1 The gear machining apparatus 1 shown has a drive device 110 (motor, etc.). That is, the control device 100 causes the hob T to rotate synchronously with the workpiece W while moving relative to it, thereby machining the tooth profile on the workpiece W.

[0063] The control device 100 consists of a CNC (Computerized Numerical Control) device, a PLC (Programmable Logic Controller), and the like. Therefore, the control device 100 has a CPU or other processing unit, a memory or other storage unit, and an interface for communicating with external devices.

[0064] In addition, such as Figure 7 As shown, the control device 100, as a functional structure, includes a first chamfering control unit 101, a tooth profile machining control unit 102, and a second chamfering control unit 103. The first chamfering control unit 101 controls the drive device 110 to perform chamfering of 62, 72, and 82 at one axial end of the tooth profile. The first chamfering control unit 101 controls the drive device 110 by executing the control program for performing the first chamfering machining operation, which will be described later.

[0065] The tooth profile machining control unit 102 controls the drive device 110 to perform tooth profile machining 61, 71, and 81. The tooth profile machining control unit 102 controls the drive device 110 by executing a control program for performing the tooth profile machining process, described later. The second chamfering machining control unit 103 controls the drive device 110 to perform chamfering 63, 73, and 83 at the other end of the tooth profile along its axial direction. The second chamfering machining control unit 103 controls the drive device 110 by executing a control program for performing the second chamfering machining process, described later.

[0066] (5. Gear Machining Methods)

[0067] Reference Figures 8-12 The gear machining method is explained below. The gear machining method is executed by the control units 101, 102, and 103 of the control device 100. The gear machining method sequentially performs the first chamfering machining step (step S1) executed by the first chamfering machining control unit 101, the tooth profile machining step (step S2) executed by the tooth profile machining control unit 102, and the second chamfering machining step (step S3) executed by the second chamfering machining control unit 103.

[0068] Here, we will illustrate the case where the workpiece W rotates only around its central axis, while the hob T rotates and moves simultaneously. However, as long as the workpiece W and the hob T move relative to each other, it is also possible to make only the hob T rotate while the workpiece W rotates and moves simultaneously, or to make both of them move.

[0069] In the first chamfering process S1, as follows Figure 9 As shown, the reference position on the central axis of the hob T is located at position P1. Therefore, in the first chamfering operation S1, position P1 is the starting position. Here, when the cross angle is 90°, the central axis of the hob T is located at position P1. However, when the cross angle is not 90°, not the entire central axis of the hob T is located at position P1. Therefore, a reference position on the centerline of the hob T is defined, and the state in which this reference position is located at position P1 is set as the starting state of the first chamfering operation S1.

[0070] Then, as Figure 10 As shown, the reference position on the central axis of the hob T is moved linearly towards position P2 relative to the workpiece W. Therefore, in the first chamfering operation S1, position P2 becomes the final position. That is, the hob T rotates synchronously relative to the workpiece W while moving axially towards the workpiece W and radially (outward in this example) towards the workpiece W. Figure 10 As shown, this action is used to process chamfers 62, 72, and 82.

[0071] Here, the linear trajectory connecting positions P1 and P2, and the line parallel to the central axis of the workpiece W, form an acute angle. (First Angle). That is, the relative movement direction of the hob T with respect to the workpiece W has a specified first angle relative to the central axis of the workpiece W. Additionally, position P2 is located axially away from end face 91 of workpiece W, away from L1 (first separation distance) in the axial direction of workpiece W. First angle The first separation distance L1 is determined by the processing condition determining device 120, which will be described later. Here, the first angle... It is an angle that is different from the tooth tip chamfer angle θt1 and tooth root chamfer angle θb1 on the axial side.

[0072] Furthermore, in this example, gear G is taken as an external gear. Therefore, in the first chamfering operation S1, the hob T is moved axially toward the workpiece W and radially outward of the workpiece W. Assuming that gear G is an internal gear, in the first chamfering operation S1, the hob T is moved axially toward the workpiece W and radially inward of the workpiece W.

[0073] The tooth profile machining process S2 is performed consecutively with the first chamfering process S1. Therefore, in the tooth profile machining process S2, as... Figure 10 As shown, position P2 becomes the starting position. Furthermore, as... Figure 11 As shown, the reference position on the central axis of the hob T is moved linearly towards position P3 relative to the workpiece W. Therefore, in the tooth profile machining operation S2, position P3 becomes the final position. That is, the hob T rotates synchronously relative to the workpiece W while moving axially towards the workpiece W. Figure 11 As shown, tooth profiles 61, 71, and 81 are machined through this action. The action of this tooth profile machining process S2 is based on the known tooth profile machining of the hob T.

[0074] Here, position P3 is located axially away from end face 92 on the other side of workpiece W, at distance L2 (second separation distance). The second separation distance L2 is determined by the machining condition determining device 120 described later.

[0075] The second chamfering process S3 is performed consecutively with the tooth profile machining process S2. Therefore, in the second chamfering process S3, position P3 becomes the starting position. Furthermore, as... Figure 12 As shown, the reference position on the central axis of the hob T is moved linearly towards position P4 relative to the workpiece W. Therefore, in the second chamfering operation S3, position P4 becomes the final position. That is, the hob T rotates synchronously relative to the workpiece W while moving axially towards the workpiece W and radially (in this example, radially inward) towards the workpiece W. Figure 12 As shown, this action is used to process chamfers (63, 73, 83).

[0076] Here, the linear trajectory connecting positions P3 and P4 forms an acute angle with the line parallel to the central axis of the workpiece W. (Second angle). That is, the relative movement direction of the hob T with respect to the workpiece W has a specified second angle relative to the central axis of the workpiece W. Second angle The processing conditions, described later, determine the device 120. Here, the second angle... It becomes an angle different from the tooth tip chamfer angle θt2 and tooth root chamfer angle θb2 on the other side of the axis.

[0077] Furthermore, in this example, gear G is taken as an external gear. Therefore, in the second chamfering operation S3, the hob T is moved axially toward the workpiece W and radially inward toward the workpiece W. Assuming that gear G is an internal gear, in the second chamfering operation S3, the hob T is moved axially toward the workpiece W and radially outward toward the workpiece W.

[0078] (6. Effects of the gear machining method performed by gear machining device 1)

[0079] The gear machining device 1 uses a hob T to perform chamfering and tooth profile machining. Specifically, by moving the hob T along the axial direction of the workpiece W in one motion, chamfering at one end of the axial direction, tooth profile machining, and chamfering at the other end of the axial direction can be performed sequentially.

[0080] More specifically, the chamfering at one axial end (62, 72, 82) is performed by the first chamfering control unit 101, which adds radial movement while moving the hob T axially toward the workpiece W. Next, the chamfers 62, 72, and 82 are processed by moving the hob T axially toward the workpiece W via the tooth profile processing control unit 102, thereby processing the tooth profiles 61, 71, and 81. That is, the chamfering at one axial end (62, 72, 82) is performed before processing the tooth profiles 61, 71, and 81. After processing the tooth profiles 61, 71, and 81, the chamfering at the other axial end (63, 73, 83) is performed by the second chamfering control unit 103. The chamfering at the other axial end (63, 73, 83) is performed by moving the hob T axially toward the workpiece W and radially toward the workpiece W.

[0081] Specifically, the machining of chamfers 62, 72, and 82 at one axial end, the machining of tooth profiles 61, 71, and 81, and the machining of chamfers 63, 73, and 83 at the other axial end are performed through a series of actions of the hob T. Therefore, for chamfering, there is no need to transport the workpiece W or change tools. Thus, the overall machining time for machining tooth profiles 61, 71, and 81 and chamfers 62, 72, 82, 63, 73, and 83 can be shortened.

[0082] (7. Processing conditions determine the structure of device 120)

[0083] To implement the gear machining method, it is necessary to determine the machining conditions for chamfers 62, 72, and 82 on one side of the axial direction and chamfers 63, 73, and 83 on the other side of the axial direction. (Refer to...) Figure 13 The machining condition determining device 120 used to determine the machining conditions will be described below. The machining condition determining device 120 determines the first angle by simulating the chamfer shape as an element of the machining conditions. Second angle First separation distance L1 and second separation distance L2 (refer to) Figure 9 ).

[0084] First, the purpose of determining machining conditions through simulation of the chamfer shape will be explained. When performing chamfering as described above, it is not easy to derive the relative movement trajectory of the hob T relative to the workpiece W. In particular, this is especially true when the teeth of the gear G and the cutting edge of the hob T have a torsion angle, or when tooth profile machining is performed with the gear G and hob T having a crossing angle. Because of these situations, it is not easy to grasp the relationship between the relative movement trajectory of the hob T and the chamfer shape.

[0085] Furthermore, as elements of the chamfer shape, there are various target shapes such as the chamfer angles θt1 and θt2 at the corners of the axial edge and the tooth thickness direction edge of the tooth tip 50, the axial chamfer lengths Ct1 and Ct2 at the corners of the axial edge and the tooth thickness direction edge of the tooth tip 50, the chamfer angles θb1 and θb2 at the corners of the tooth root 61 and the axial end faces 91 and 92 of the tooth profile of the workpiece W, and the axial chamfer lengths Cb1 and Cb2 at the corners of the tooth root 61 and the axial end faces 91 and 92 of the tooth profile of the workpiece W.

[0086] Therefore, for example, the relative movement trajectory of the hob T cannot be simply derived based on the chamfer angles θt1, θt2, θb1, θb2 and the outer diameter of the hob T. Therefore, a simulation of the chamfer shape is performed, thereby determining a machining condition related to the relative movement trajectory of the hob T relative to the workpiece W where the chamfer shape meets specified allowable conditions. As a result, it is possible to determine the machining conditions that ensure the chamfer shape meets the specified allowable conditions.

[0087] The processing condition determining device 120 can also be configured Figure 1 The gear processing apparatus 1 shown can also be provided as a separate device from the gear processing apparatus 1. When the processing condition determination device 120 is part of the gear processing apparatus 1, it can be integrated with the mechanical structure of the gear processing apparatus 1, or it can be located at a different position from the mechanical structure of the gear processing apparatus 1, forming a network. When the processing condition determination device 120 utilizes the CNC device of the control device 100 constituting the gear processing apparatus 1, it is preferably configured as an assembly system of the control device 100. Furthermore, the processing condition determination device 120 includes a processing unit such as a CPU, a storage device such as a memory, and an interface for communication with external machines. The processing condition determination device 120 may also include an input device and a display device.

[0088] like Figure 13 As shown, the processing condition determination device 120 has a parameter acquisition unit 121, a simulation processing unit 122, a determination unit 123, and a parameter modification unit 124 as a functional structure.

[0089] The parameter acquisition unit 121 acquires the first angle as a parameter of the processing conditions. Second angle The first separation distance L1 and the second separation distance L2. The parameter acquisition unit 121 may acquire only the initial value of each parameter, or it may acquire multiple values ​​for each parameter.

[0090] The simulation processing unit 122 uses a parameter obtained by the parameter acquisition unit 121 to simulate the gear machining method described above. In this way, the simulation processing unit 122 can obtain the shape of the machined workpiece W, especially the chamfer shape. Specifically, the chamfer angles θt1, θt2, θb1, θb2 and the chamfer lengths Ct1, Ct2, Cb1, Cb2 can be obtained as elements of the chamfer shape.

[0091] The determination unit 123 determines whether the chamfer shape of the processed workpiece W obtained by the simulation processing unit 122 meets the specified allowable conditions. Specifically, the determination unit 123 determines whether each element of the chamfer shape meets the specified allowable conditions.

[0092] Based on the determination result of the determination unit 123, the parameter modification unit 124 modifies the simulation parameters performed by the simulation processing unit 122 if the specified allowable conditions are not met. If the parameter acquisition unit 121 only acquires an initial value, the parameter modification unit 124 modifies the parameter value by applying appropriate changes to the initial value, causing the simulation processing unit 122 to use the modified parameter value for simulation. If the parameter acquisition unit 121 acquires multiple values, the parameter modification unit 124 causes the simulation processing unit 122 to use the values ​​of the other parameters for simulation.

[0093] As described above, the simulation processing unit 122 simulates the chamfer shape for various processing conditions, thereby enabling the determination unit 123 to determine a processing condition in which the chamfer shape meets the specified allowable conditions.

[0094] Furthermore, the processing conditions determined by the processing condition determining device 120 are used for control of the control device 100. Specifically, the first chamfering processing control unit 101 is based on a first angle, which is an element of the determined processing conditions. The drive unit 110 is controlled based on the first separation distance L1 and the second separation distance L2, which are factors of the determined machining conditions. The second chamfering control unit 103 controls the drive unit 110 based on the second angle, which is a factor of the determined machining conditions. And the second separation distance L2, to control the drive unit 110.

[0095] (8. Examples of conditions determining the course of action)

[0096] Reference Figure 14Let me illustrate an example of the condition determination process performed by the processing condition determination device 120. In this example, we assume that the parameter acquisition unit 121 acquires the initial values ​​of the parameters.

[0097] First, the parameter acquisition unit 121 obtains the first angle as a factor of the processing conditions for the first chamfering process S1. And the initial value of the first separation distance L1 (step S11). Next, simulation is performed by the simulation processing unit 122 (step S12). Next, the shape θt1, θb1, Ct1, Cb1 of the chamfers 62, 72, 82 on one side of the axis is determined by the determination unit 123 (step S13). Next, if the determination result does not meet the specified allowable conditions (step S14: No), the parameters are changed by the parameter changing unit 124. The value of L1 (step S15). Then, return to step S12 again to perform the simulation.

[0098] Therefore, simulations are repeated for different parameter values ​​until the shapes θt1, θb1, Ct1, Cb1 of the chamfers 62, 72, and 82 on one side of the axial direction meet the specified allowable conditions. Then, if the specified allowable conditions are met (S14: Yes), the values ​​that meet the specified allowable conditions will be... The value of L1 is determined as an element of the processing conditions (step S16).

[0099] Next, the parameter acquisition unit 121 obtains the second angle as a factor of the processing conditions for the second chamfering process S3. And the initial value of the second separation distance L2 (step S17). Next, simulation is performed by the simulation processing unit 122 (step S18). Next, the shape θt2, θb2, Ct2, Cb2 of the chamfers 63, 73, 83 on the other side of the axis is determined by the determination unit 123 (step S19). Next, if the determination result does not meet the specified allowable conditions (step S20: No), the parameters are changed by the parameter changing unit 124. The value of L2 (step S21). Then, return to step S18 again to perform the simulation.

[0100] Therefore, simulations are repeated for different parameter values ​​until the shapes θt2, θb2, Ct2, Cb2 of the chamfers 63, 73, 83 on the other side of the axis meet the specified allowable conditions. Then, if the specified allowable conditions are met (S20: Yes), the values ​​that meet the specified allowable conditions will be... The value of L2 is determined as an element of the processing conditions (step S22).

[0101] This allows for the determination of processing conditions. Furthermore, in the aforementioned condition-determining process, a first-angle approach is taken through different procedures. And the determination of the first separation distance L1, and the second angle And the determination of the second separation distance L2. In addition, it is also possible to consider all processing condition elements. L1 and L2 are used for simulation and judgment in one go.

Claims

1. A gear processing device, characterized in that, have: A hob, which processes tooth profiles on a workpiece; and The control device causes the hob and the workpiece to rotate synchronously and move relative to each other. The aforementioned control device includes: The first chamfering control unit moves the hob relative to the workpiece in the axial direction and in the radial direction, thereby moving it relative to the workpiece from the starting position (P1) to the position (P2) which is the first target position, so that the hob performs chamfering on one end of the tooth profile in the axial direction during the relative movement from the starting position to the first target position. The tooth profile machining control unit continuously continues the chamfering machining of one axial end of the tooth profile, causing the hob to move relative to the workpiece in the axial direction of the workpiece, thereby moving relative to the first target position to the position (P3) which is the second target position, and machining the tooth profile during the relative movement of the hob from the first target position to the second target position. as well as The second chamfering control unit continuously continues the machining of the tooth profile, causing the hob to move relative to the workpiece in the axial direction and in the radial direction, thereby moving relative to the workpiece from the second target position to the third target position (P4), so that the hob performs chamfering machining on the other end of the tooth profile in the axial direction during the relative movement from the second target position to the third target position.

2. The gear processing apparatus according to claim 1, characterized in that, The aforementioned first chamfering control unit controls the movement of the hob relative to the workpiece at a predetermined first angle relative to the workpiece's central axis. The aforementioned second chamfering control unit controls the movement of the hob relative to the workpiece at a predetermined second angle relative to the workpiece's central axis. The aforementioned first angle is set to an angle different from the chamfer angle of one end of the axial direction of the aforementioned tooth profile. The second angle mentioned above is set to be different from the chamfer angle at the other end of the axial direction of the tooth profile.

3. The gear processing apparatus according to claim 1, characterized in that, It also has: The machining condition determining device simulates various machining conditions related to the relative movement trajectory of the hob relative to the workpiece for each of the chamfering machining at one axial end of the aforementioned tooth profile and the chamfering machining at the other axial end of the aforementioned tooth profile, thereby determining a machining condition related to the relative movement trajectory of the hob relative to the workpiece in which the chamfer shape satisfies the specified allowable conditions. The first chamfering control unit and the second chamfering control unit control the process based on the processing conditions determined by the processing condition determining device.

4. The gear processing apparatus according to claim 2, characterized in that, It also has: The processing condition determining device simulates various processing conditions related to the relative movement trajectory of the hob relative to the workpiece for each of the chamfering processing at one axial end of the aforementioned tooth profile and the chamfering processing at the other axial end of the aforementioned tooth profile. It then determines a processing condition related to the relative movement trajectory of the hob relative to the workpiece in which the chamfer shape satisfies the specified allowable conditions. The first chamfering processing control unit and the second chamfering processing control unit perform control based on the processing condition determined by the processing condition determining device.

5. The gear processing apparatus according to claim 3, characterized in that, The machining conditions of the first chamfering machining control unit include a first angle representing the relative movement direction of the hob relative to the workpiece, and an end position of the relative movement toward the first angle. The processing conditions of the second chamfering control unit include a second angle representing the relative movement direction of the hob relative to the workpiece, and a starting position for relative movement toward the second angle.

6. The gear processing apparatus according to claim 4, characterized in that, The machining conditions of the first chamfering machining control unit include a first angle representing the relative movement direction of the hob relative to the workpiece, and an end position of the relative movement toward the first angle. The processing conditions of the second chamfering control unit include a second angle representing the relative movement direction of the hob relative to the workpiece, and a starting position for relative movement toward the second angle.

7. The gear processing apparatus according to any one of claims 3 to 6, characterized in that, The elements of the above-mentioned chamfer shape include: The chamfer angle of the corner between the axial edge of the tooth tip and the edge in the tooth thickness direction of the aforementioned tooth profile. The axial chamfer length of the corner between the axial edge of the tooth tip and the edge in the tooth thickness direction of the above-mentioned tooth profile. The chamfer angle between the tooth root of the axial section of the above-mentioned workpiece and the corner of the axial end face of the above-mentioned tooth profile. The axial chamfer length of the corner between the tooth root of the axial section of the above-mentioned workpiece and the axial end face of the above-mentioned tooth profile. At least one of them.

8. A machining condition determining device for determining machining conditions in a gear machining method that uses a hob to machine tooth profiles on a workpiece, characterized in that, The above gear machining method includes: In the first chamfering process, the hob is moved relative to the workpiece in the axial direction and in the radial direction, thereby moving relative to the workpiece from the starting position (P1) to the position (P2) which is the first target position. During the relative movement of the hob from the starting position to the first target position, the hob is chamfered at one end of the tooth profile in the axial direction. In the tooth profile machining process, the chamfering of one end of the tooth profile is continuously carried out, and the hob moves relative to the workpiece in the axial direction of the workpiece, thereby moving relative to the first target position to the position (P3) which is the second target position, and the hob processes the tooth profile during the relative movement from the first target position to the second target position. as well as The second chamfering process continues uninterruptedly from the machining of the aforementioned tooth profile. The hob is moved relative to the workpiece axially and radially, thereby moving relative to the workpiece from the second target position to the third target position (P4). During this relative movement from the second target position to the third target position, the hob performs chamfering on the other axial end of the aforementioned tooth profile. For each of the chamfering processes at one axial end of the aforementioned tooth profile and the chamfering process at the other axial end of the aforementioned tooth profile, the chamfer shape is simulated under various processing conditions related to the relative movement trajectory of the hob relative to the workpiece, thereby determining a processing condition related to the relative movement trajectory of the hob relative to the workpiece in which the chamfer shape satisfies the specified allowable conditions.

9. The processing condition determining device according to claim 8, characterized in that, The elements of the above-mentioned chamfer shape include: The chamfer angle of the corner between the axial edge of the tooth tip and the edge in the tooth thickness direction of the aforementioned tooth profile. The axial chamfer length of the corner between the axial edge of the tooth tip and the edge in the tooth thickness direction of the above-mentioned tooth profile. The chamfer angle between the tooth root of the axial section of the above-mentioned workpiece and the corner of the axial end face of the above-mentioned tooth profile. The axial chamfer length of the corner between the tooth root of the axial section of the above-mentioned workpiece and the axial end face of the above-mentioned tooth profile. At least one of them, The processing conditions that determine at least one of the chamfer angle of the tooth tip, the axial chamfer length of the tooth tip, the chamfer angle of the tooth root, and the axial chamfer length of the tooth root, which are elements of the chamfer shape, satisfy the aforementioned specified allowable conditions.

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