Tool, gear machining device, and gear machining method

Abstract

A tool 10 comprises: a first tool member 11 having first machining blades 11B that are formed on an outer peripheral surface of a first tool body 11A and perform first machining on a gear W to be machined; and a second tool member 12 having second machining blades 12B that are formed on an outer peripheral surface of a second tool body 12A and perform second machining on the gear W to be machined. The tool 10 is formed such that, in a state in which the first tool member 11 and the second tool member 12 are combined, the first machining blades 11B of the first tool member 11 protrude toward the second tool member 12, and the second machining blades 12B of the second tool member 12 are located with a predetermined interval in a circumferential direction from the protruding portions of the first machining blades 11B.

Description

Tool, gear processing device, and gear processing method

[0001] The present invention relates to a tool, a gear machining apparatus, and a gear machining method.

[0002] A chamfering cutter, such as that disclosed in Patent Document 1, is known from the past. The conventional chamfering cutter has a chamfered portion and a deburring portion formed on the outer periphery of a disc-shaped cutter body. The chamfered portion is formed by an array of one or more chamfering blades (chamfering blades) that chamfer the ends of the teeth of the gear to be processed by pressing against the ends. The deburring portion is formed by an array of one or more deburring blades that cut and remove burrs that are generated when the chamfering blade presses against the ends of the teeth of the gear to be processed. In the conventional chamfering cutter, the chamfered portion and the deburring portion are arranged alternately in the circumferential direction along the outer periphery of the cutter body.

[0003] JP 2013-56403 A

[0004] In the conventional framing cutter described above, the framing blade presses against the end face of the gear tooth to chamfer it, and the deburring blade presses against the protrusions that result from the chamfering to smooth them out as burrs. In other words, although the framing blade and deburring blade of conventional framing cutters have different processing purposes, both perform only rolling, i.e., pressing the processing point in one direction to crush the cutting point so that the planar shape of the blade is transferred to the processing point.

[0005] However, different machining processes may be required for a workpiece while it is rotating and meshing with a tool. When the workpiece is a gear, in addition to the chamfering process (i.e., framing process) described above, relief machining may be required to remove corners while moving the machining point relative to the workpiece in order to improve tooth rattle. Furthermore, when the workpiece is a gear, shaving may be required to remove irregularities (so-called polygonal errors) on the tooth surface of the gear while moving the machining point relative to the workpiece in order to achieve smooth meshing.

[0006] In these cases, with the conventional chamfering cutter described above, after chamfering and deburring, it is necessary to change to a relief cutter if relief processing is required, or to a shaving cutter if shaving processing is required. In other words, with the conventional chamfering cutter, if processing is required while moving the processing point relative to the workpiece, a changeover is required. Therefore, the more frequently changeovers are required to accommodate multiple processing operations, the more time is required for the changeover. Therefore, when processing a gear, which is a workpiece, using a conventional chamfering cutter, there is room for improvement in terms of improving production efficiency.

[0007] An object of the present invention is to provide a tool that can improve production efficiency, a gear machining apparatus using the tool, and a gear machining method using the tool.

[0008] The tool of the present invention is a tool having multiple machining blades, including a first machining blade formed on the outer surface of the tool body so as to be parallel to the rotation axis of the disk-shaped tool body and performing a first machining operation on the workpiece, and a second machining blade formed on the outer surface so as to be twisted about the rotation axis and having a blade length along the direction of the rotation axis longer than the first machining blade so that the machining point on the workpiece can be moved and performing a second machining operation on the workpiece, and the first machining blades and second machining blades are arranged alternately along the outer surface.

[0009] In this case, as an example, the tool body is formed by a disk-shaped first tool body and a disk-shaped second tool body, and is equipped with a first tool member formed on the outer peripheral surface of the first tool body and having a first processing blade for performing a first processing on the workpiece, and a second tool member formed on the outer peripheral surface of the second tool body and having a second processing blade for performing a second processing on the workpiece, and when the first tool member and the second tool member are combined so that the rotation axes of the first tool body and the second tool body are coaxial, one of the processing blades of the first tool member and the second tool member is formed to protrude toward the other of the first tool member and the second tool member, and the other processing blade is formed to be positioned at a predetermined distance in the circumferential direction from the protruding portion of one processing blade.

[0010] The gear machining device of the present invention comprises the above-mentioned tool, a tool spindle that rotates and drives the tool, a work spindle that rotatably supports a gear to be machined as a workpiece, and a moving device that moves the work spindle and the tool spindle relative to each other so that the tool supported by the tool spindle and the gear to be machined supported by the work spindle can mesh with each other, and repeatedly performs the first machining and the second machining in one machining step.

[0011] Furthermore, a gear machining method of the present invention comprises the above-mentioned tool, a tool spindle that rotationally drives the tool, a work spindle that rotatably supports a gear to be machined as a workpiece, and a moving device that moves the work spindle and the tool spindle relative to each other so that the tool supported by the tool spindle and the gear to be machined supported by the work spindle can mesh with each other, and by performing the first machining followed by the second machining and the first machining followed by the second machining, the first machining and the second machining are repeatedly performed in succession.

[0012] According to the present invention, the tool can be equipped with a first processing blade for performing a first processing step and a second processing blade for performing a second processing step that moves the processing point differently from the first processing step. The tool can then perform the first and second processing steps on the workpiece repeatedly and continuously. This eliminates the need for time for setup changes and the like compared to performing the first and second processing steps separately on the workpiece, i.e., performing only the first processing step and then the second processing step. This allows the tool to shorten the processing time. Therefore, the tool can improve the production efficiency of workpieces.

[0013] FIG. 1 is a schematic configuration diagram of a tool and a gear machining device according to an embodiment. FIG. 2 is a diagram for explaining the names of a workpiece gear, which is a workpiece. FIG. 3 is a diagram for explaining the names of a tool. FIG. 4 is a schematic configuration diagram of a tool according to an embodiment. FIG. 5 is a diagram for explaining the configuration of the tool according to an embodiment. FIG. 6 is a flowchart showing an example of a gear machining method. FIG. 7 is a diagram for explaining the operation of the gear machining device. FIG. 8 is a diagram for explaining meshing between the tool and the workpiece gear according to an embodiment. FIG. 9 is a diagram along a pitch circle showing first and second machining of the workpiece gear by the tool unit according to an embodiment. FIG. 10 is a schematic configuration diagram of a tool according to a first modified example. FIG. 11 is a diagram for explaining the operation of the gear machining device according to the first modified example. FIG. 12 is a diagram for explaining the configuration of a tool according to a second modified example. FIG. 13 is a diagram for explaining meshing between the tool and the workpiece gear according to the second modified example. FIG. 14 is a diagram along a pitch circle showing first and second machining of the workpiece gear by the tool unit according to a third modified example. FIG. 15 is a diagram along a pitch circle showing first and second machining of the workpiece gear by the tool unit according to a fourth modified example. FIG. 16 is a diagram along a pitch circle showing first and second machining of the workpiece gear by the tool unit according to a fifth modified example. 10A and 10B are views taken along a pitch circle showing first and second machining of a workpiece gear by a tool unit of a fifth modified example; FIG. 10B are views taken along a pitch circle showing first and second machining of a workpiece gear by a tool unit of a fifth modified example; FIG. 10C are views taken along a pitch circle showing first and second machining of a workpiece gear by a tool unit of a sixth modified example; FIG. 10D are views taken along a pitch circle showing first and second machining of a workpiece gear by a tool unit of a sixth modified example; FIG. 10E are views taken along a pitch circle showing first and second machining of a workpiece gear by a tool unit of a seventh modified example; FIG. 10F are views taken along a pitch circle showing first and second machining of a workpiece gear by a tool unit of a seventh modified example; FIG. 10H are views taken along a pitch circle showing first and second machining of a workpiece gear by a tool unit of a seventh modified example; FIG. 10H are views for explaining the difference in blade height between a first machining blade and a second machining blade according to an eighth modified example; FIG. 10H are views for explaining eccentricity of a first tool member and a second tool member according to a ninth modified example; and FIG. 10H are views for explaining a coating layer according to a tenth modified example.

[0014] (1. Configuration of Gear Machining Apparatus 1) The configuration of the gear machining apparatus 1 will be described with reference to FIG. 1. The gear machining apparatus 1 is a machine tool that performs predetermined machining processes, such as rolling, cutting, or grinding, on a workpiece. In this embodiment, the workpiece that is machined by the gear machining apparatus 1 is, for example, a gear W to be machined, in which workpiece teeth W1 are generated by a gear cutting process (description omitted) using a gear cutter such as a hob or gear shaper. Hereinafter, the gear W to be machined may be simply referred to as the "gear workpiece W."

[0015] In addition, the gear workpiece W may have helical teeth generated through a gear cutting process, or may have spur teeth generated through a gear cutting process. In this embodiment, a case where the workpiece teeth W1 are helical teeth will be described as an example.

[0016] The gear machining device 1 performs rolling, cutting, or grinding on a gear workpiece W while rotating the gear workpiece W and a tool 10 (described later) in a state where the gear workpiece W is engaged with the tool 10. For this reason, examples of the gear machining device 1 include a machining center, lathe, grinding machine, etc., equipped with multiple drive axes that change the relative position and attitude of the gear workpiece W and the tool 10.

[0017] 1 , the gear machining device 1 mainly includes a base 2, a workpiece spindle 3, a Z-axis moving table 4, a swivel table 5, a tool spindle 6, an X-axis moving table 7, a deburring roller 8, and a control device 9. The gear machining device 1 also includes a tool unit T1 that is attached to the tool spindle 6 and includes a tool 10.

[0018] Here, the gear machining apparatus 1 has, for example, an X-axis, a Y-axis, and a Z-axis that are orthogonal to one another. The direction of the rotation axis Cw of the gear workpiece W (the rotation axis Cw of the workpiece spindle 3) is defined as the Y-axis direction, and the two axes that are orthogonal to the Y-axis direction are defined as the X-axis direction and the Z-axis direction. In Fig. 1, in the gear machining apparatus 1, the horizontal direction is the X-axis direction, the vertical direction is the Y-axis direction, and the depth direction is the Z-axis direction.

[0019] The gear cutting device 1 also has a rotation axis Ct (rotation axis Ct of the tool spindle 6) that is provided along the Y-axis direction and that rotates and drives the tool 10. The gear cutting device 1 also has a rotation axis Cr that is provided along the Y-axis direction and that supports the deburring roller 8 so that it can rotate freely. Furthermore, in the gear cutting device 1, the tool spindle 6 has a C-axis (a rotation axis about the Z-axis in the reference state shown in FIG. 1 ) that changes the relative attitude between the gear workpiece W and the tool 10, as will be described in detail later.

[0020] The base 2 is fixed on an installation surface and is formed in any shape, such as a substantially rectangular shape.

[0021] The work spindle 3 is provided on the top surface of the base 2, approximately in the center in the X-axis direction and on the front side in the Z-axis direction. The work spindle 3 supports the gear workpiece W so that it can freely rotate around the Y-axis, i.e., around the rotation axis Cw. As a result, as will be described later, when the tool 10 (tool unit T1) held by the tool spindle 6 is rotated while meshed with the gear workpiece W, the gear workpiece W supported by the work spindle 3 rotates together with the tool 10.

[0022] The Z-axis moving table 4, which serves as a moving device, is provided so as to be movable in the Z-axis direction relative to the base 2. Specifically, a pair of Z-axis guide rails 4A extending in the Z-axis direction is provided on the upper surface of the base 2. The Z-axis moving table 4 is driven by a linear motor, a ball screw mechanism, or the like (not shown). As a result, the Z-axis moving table 4 moves back and forth in the Z-axis direction, i.e., relative to the gear workpiece W and the workpiece spindle 3, while being guided by the pair of Z-axis guide rails 4A.

[0023] The rotating table 5 as a moving device is installed on the side of the Z-axis moving table 4 facing the gear workpiece W, and moves back and forth in the Z-axis direction together with the Z-axis moving table 4. The rotating table 5 is also provided so as to be rotatable about the C-axis relative to the Z-axis moving table 4. The rotating table 5 is driven by a rotary motor (not shown) to be rotatable about the C-axis.

[0024] In the reference state shown in FIG. 1 , the tool spindle 6 is arranged parallel to the Y-axis direction. The tool spindle 6 is rotatably supported by the swivel table 5 and moves in the Z-axis direction together with the swivel table 5 and the Z-axis moving table 4, i.e., moves relative to the workpiece spindle 3. The tool spindle 6 is rotationally driven by a spindle motor 6A provided on the swivel table 5. The tool spindle 6 supports a tool unit T1 including a tool 10. The tool spindle 6 has a tool holder (not shown), and the tool unit T1 is attached to the tip of the tool spindle 6 by being held by the tool holder. As a result, the tool 10 rotates as the tool spindle 6 is rotated by the spindle motor 6A.

[0025] The X-axis moving table 7 is provided so as to be movable in the X-axis direction relative to the base 2. Specifically, on the upper surface of the base 2, an X-axis guide rail 7B extending in the X-axis direction is provided on a support portion 7A erected in the X-axis direction (to the right of the work spindle 3 in FIG. 1 ) and forward in the Z-axis direction relative to the work spindle 3. The X-axis moving table 7 is driven by a linear motor or a ball screw mechanism (not shown). As a result, the X-axis moving table 7 moves back and forth in the X-axis direction, i.e., relative to the gear workpiece W, while being guided by the X-axis guide rail 7B.

[0026] The deburring roller 8 removes burrs that occur on the gear workpiece W during machining. The deburring roller 8 is mounted on the X-axis moving table 7 and moves back and forth in the X-axis direction together with the X-axis moving table 7. The deburring roller 8 also includes a pair of rollers 8A. In this embodiment, the pair of rollers 8A are driven by a drive mechanism (not shown) to move toward or away from each other along the rotation axis Cr, i.e., the Y-axis direction.

[0027] As a result, the deburring roller 8 moves integrally with the X-axis moving table 7, thereby approaching the gear workpiece W. The pair of rollers 8A of the deburring roller 8 sandwich the side surfaces of the gear workpiece W in the direction of the rotation axis Cw, thereby removing burrs (protrusions) formed on the side surfaces of the gear workpiece W. With the pair of rollers 8A sandwiching the gear workpiece W, the deburring roller 8 rotates along with the gear workpiece W as the gear workpiece W rotates, i.e., as the tool 10 is rotated.

[0028] The control device 9 controls the operation of the gear machining device 1 based on an NC program generated based on operation command data such as the shape of the workpiece tooth W1 in the gear workpiece W, machining conditions, and the shape of the tool 10 (tool unit T1). That is, the control device 9 inputs the operation command data and generates an NC program based on the operation command data. The control device 9 then controls the motors including the spindle motor 6A based on the generated NC program, thereby machining the workpiece tooth W1 of the gear workpiece W (gear W to be machined). Here, the operation command data includes, for example, a command cutting speed, a command position, a command rotational speed of the tool 10, and a command pressing force with which the tool 10 presses the gear workpiece W.

[0029] Here, as shown in Figure 2, in the following description, the radial direction of the gear workpiece W will be referred to as the "workpiece radial direction." Furthermore, in the following description, the "tooth trace direction" corresponds to the extension direction of a continuous workpiece tooth W1 that continues from one end to the other in the direction of the rotation axis Cw of the gear workpiece W. If the gear workpiece W has helical teeth, the tooth trace direction is inclined with respect to the rotation axis Cw of the gear workpiece W. Furthermore, if the gear workpiece W has spur teeth, the tooth trace direction is parallel to the rotation axis Cw of the gear workpiece W. For ease of understanding, Figure 2 illustrates an example in which the gear workpiece W has spur teeth.

[0030] In the following description, the "end W2" and the "fraging portion W2" correspond to both ends in the tooth trace direction, as shown by the thick lines in Fig. 2. In this case, when the "end W2" is subjected to framing and chamfered, the "fraging portion W2" is formed in the "end W2".

[0031] Furthermore, in the following description, the "corner W3" and the "relief W3" correspond to one of the four corners in the tooth trace direction. That is, the "corner W3" is an area present on the tooth tip side and tooth base side of the work tooth W1, as indicated by dots in Figure 2. When the "corner W3" is subjected to relief machining to remove the corner, the "relief W3" is formed in the "corner W3."

[0032] 3, in the following description, "blade height" refers to the radial distance from the base to the tip of the first processing blade 11B and the second processing blade 12B in the case of the tool 10 described later. In the following description, "blade length" refers to the length of the first processing blade 11B and the second processing blade 12B extending from one end to the other in the direction of the rotation axis Ct of the tool 10 in the case of the tool 10.

[0033] (2. Configuration of tool unit T1) Next, the configuration of the tool unit T1 attached to the tool spindle 6 of the gear machining device 1 will be described. As shown in Fig. 4, the tool unit T1 of this embodiment includes a tool 10, a spacer 13, and a framing cutter 14. The tool unit T1 is assembled integrally via the spacer 13 so that the tool 10 and the framing cutter 14 are coaxial and spaced apart by a distance corresponding to the tooth width in the tooth trace direction of the gear workpiece W. The tool 10 and the framing cutter 14 are fixed to the spacer 13, for example, by bolts (not shown).

[0034] (2-1. Configuration of tool 10)

[0035] The tool 10 is a rolling die and includes a first tool member 11 and a second tool member 12. The tool 10 is formed by combining the first tool member 11 and the second tool member 12. As a result, in the tool unit T1, the tool 10, which is a combination of the first tool member 11 and the second tool member 12, and the chamfering cutter 14 are fixed to the spacer 13.

[0036] The first tool member 11 is a tool member that performs a first machining operation on the workpiece tooth W1 of the gear workpiece W. The first tool member 11 includes a disk-shaped first tool body 11A. The first tool member 11 also includes a first machining blade 11B formed on the outer peripheral surface of the first tool body 11A. Here, the "first machining operation" in this embodiment is a framing operation (chamfering operation) that chamfers the end W2 of the workpiece tooth W1. Therefore, the first machining blade 11B in this embodiment is a framing blade that is formed parallel to the rotation axis Ct of the first tool body 11A and performs the framing operation.

[0037] The second tool member 12 is a tool member that performs a second machining operation, which is different from the first machining operation, on the workpiece tooth W1 of the gear workpiece W. The second tool member 12 includes a disk-shaped second tool body 12A that is different from the first tool body 11A. The second tool member 12 also includes a second machining blade 12B formed on the outer peripheral surface of the second tool body 12A. Here, the "second machining operation" in this embodiment is a relief machining operation that removes a corner W3 of one of the four corners of the workpiece tooth W1. Therefore, the second machining blade 12B in this embodiment is a relief blade that is formed to twist with respect to the rotation axis Ct of the second tool body 12A (i.e., has a helical tooth shape) and performs the relief machining.

[0038] Here, the blade length of the first processing blade 11B parallel to the rotation axis Ct of the tool 10 corresponds to the length obtained by adding the protrusion of the protrusion 11C (described later) to the thickness of the first tool body 11A (the distance in the direction of the rotation axis Ct). The second processing blade 12B twists with respect to the rotation axis Ct of the tool 10, i.e., is inclined with respect to the rotation axis Ct, and therefore extends along the circumferential direction of the second tool body 12A. The blade length of the second processing blade 12B is longer than the blade length of the first processing blade 11B.

[0039] In the tool 10, the first tool member 11 and the second tool member 12 are combined with each other. Specifically, the first tool member 11 and the second tool member 12 are combined with each other so that the rotation axes Ct of the first tool body 11A and the second tool body 12A are coaxial. In this case, one of the processing blades of the first tool member 11 and the second tool member 12, i.e., the first processing blade 11B in this embodiment, as shown in FIGS. 4 and 5 , has a protruding portion 11C that protrudes toward the other of the first tool member 11 and the second tool member 12, the second tool member 12. The second tool member 12 is formed with a second processing blade 12B so as to be positioned at a predetermined circumferential distance from the protruding portion 11C of the first processing blade 11B of the first tool member 11.

[0040] More specifically, the forming pitch of the cutting blade of the framing cutter 14 is the same as the forming pitch of the workpiece teeth W1 created on the gear workpiece W. When the forming pitch of the framing cutter 14 is used as a reference, the forming pitch of the first cutting blade 11B and the forming pitch of the second cutting blade 12B are larger than the forming pitch of the framing cutter 14, assuming that they are the same forming pitch.

[0041] That is, as shown in Fig. 5, the second tool member 12 should originally have the second processing blades 12B formed at the same forming pitch as the framing cutter 14. However, in this embodiment, the second tool member 12 has a removed portion 12C indicated by a dashed line in Fig. 5 by removing a portion of the second processing blade 12B. As a result, when the first tool member 11 and the second tool member 12 are combined, the protruding portion 11C of the first processing blade 11B enters the removed portion 12C of the second tool member 12, in other words, between two second processing blades 12B adjacent in the circumferential direction. Therefore, in this embodiment, the first processing blade 11B and the second processing blade 12B are spaced apart from each other in the circumferential direction.

[0042] (3. Gear Machining Method) Next, a gear machining method will be described in which, for example, frazing and relieving are performed on a gear workpiece W (machined gear W) before heat treatment, with the tool unit T1 including the tool 10 attached to the gear machining device 1 described above. Note that the gear workpiece W is subjected to frazing and relieving before heat treatment, so that a rough framing portion W2 and a relief portion W3 are formed in advance. Finally, the workpiece teeth W1 are subjected to finishing grinding or the like, so that the gear workpiece W is produced as a finished gear.

[0043] When gears, which are products, mesh together to transmit power, the smooth meshing of the two gears may be impaired when they begin to mesh due to the presence of burrs or protrusions on the edges. If smooth meshing is impaired in this way, noise may be generated as the gears rotate, and the teeth may be damaged.

[0044] Therefore, in this embodiment, the first processing blade 11B and the framing cutter 14 are engaged with both end portions W2 of the workpiece tooth W1 in the tooth trace direction. The first processing blade 11B and the framing cutter 14 then cut into the workpiece tooth W1 while rotating, thereby performing a rolling process in which the end portions W2 are pressed and crushed with their respective blade faces, i.e., a framing process. This forms a chamfered framing portion W2 at the end portions W2 of the workpiece tooth W1, achieving smooth gear meshing.

[0045] Furthermore, when gears are meshed together to transmit power, deflection of the gear teeth can cause a phase shift in the meshing when the gears begin to mesh. If a phase shift occurs at the beginning of meshing, the teeth can interfere significantly, resulting in high surface pressure at the point where meshing begins, potentially damaging the teeth.

[0046] Therefore, in this embodiment, the second processing blade 12B moves the processing point along the tooth trace direction while rotating while meshing with the workpiece tooth W1. As a result, the second processing blade 12B performs relief processing by pressing an area of ​​the tooth flank of the workpiece tooth W1 where high surface pressure occurs at the beginning of meshing, specifically, one of the four corners W3 of the tooth flank. Then, the corner of the corner W3 of the tooth flank is removed to form the relief portion W3, that is, the thickness of the portion of the workpiece tooth W1 where the relief portion W3 is formed is reduced, thereby suppressing the generation of high surface pressure.

[0047] Specifically, in the gear cutting method of this embodiment, the control device 9 executes a gear cutting step in which the first cutting and the second cutting are sequentially and continuously repeated in step S11. Then, in step S12, the control device 9 determines whether the gear cutting step has been executed for a predetermined time, and if so, ends the process in step S13.

[0048] As described above, the tool 10 is a combination of a first tool member 11 for performing frazing and a second tool member 12 for performing relief. In other words, by combining the first tool member 11 and the second tool member 12 in the tool 10, frazing blades, which are spur-toothed first cutting blades 11B, and relief blades, which are helical-toothed second cutting blades 12B, are arranged alternately along the circumferential direction. This allows the first tool member 11 and the second tool member 12 to alternately perform frazing and relief on the workpiece tooth W1 at one end of the gear workpiece W in the tooth trace direction when the gear workpiece W and the tool 10 are engaged. Therefore, in the gear machining process of step S11, the gear machining device 1 can repeatedly and consecutively perform frazing and relief machining in sequence.

[0049] (3-1. Gear Machining Process) As shown in Figure 7, the gear machining process is a process in which a gear workpiece W before heat treatment is rotated in mesh with a tool 10 to perform framing and relief machining on the workpiece teeth W1. By performing framing and relief machining before heat treatment, it is possible to form rough framing portions W2 and relief portions W3 in advance before finish machining. This shortens the machining time required for finish machining, improving productivity and ultimately making it possible to manufacture high-performance gears with higher load capacities while suppressing increases in manufacturing costs.

[0050] The control device 9 first moves the Z-axis moving table 4 in the Z-axis direction as shown by the thick arrow in Fig. 7. That is, the control device 9 moves the tool spindle 6, i.e., the tool unit T1 including the tool 10, toward the gear workpiece W. The control device 9 also moves the X-axis moving table 7 in the X-axis direction as shown by the thick arrow in Fig. 7. That is, the control device 9 moves the deburring roller 8 toward the gear workpiece W.

[0051] 8, the control device 9 brings the first processing blade 11B or the second processing blade 12B of the tool 10 into mesh with the workpiece tooth W1 of the gear workpiece W, and brings the chamfering cutter 14 of the tool unit T1 into mesh with the workpiece tooth W1 of the gear workpiece W. In this case, the control device 9 can bring the gear workpiece W into mesh with the tool 10 by, for example, rotating the tool spindle 6 at an extremely low speed while reciprocating the Z-axis moving table 4.

[0052] 7, the control device 9 moves the pair of rollers 8A of the deburring roller 8 that has moved near the gear workpiece W closer to each other. As a result, the pair of rollers 8A of the deburring roller 8 hold the side surfaces of the gear workpiece W. During the framing process, the control device 9 can, for example, reciprocate the X-axis moving table 7 so that the deburring rollers 8 rotate along with the gear workpiece W while holding the side surfaces of the gear workpiece W.

[0053] 8, the control device 9 controls the motors (not shown) and the like to move the Z-axis moving table 4 so that the tool 10 and the framing cutter 14 meshed with the gear workpiece W press the gear workpiece W with a predetermined pressing force in the Z-axis direction. In other words, during machining, the tool 10 and the framing cutter 14 are always maintained in a state where they press the gear workpiece W with a predetermined pressing force.

[0054] Next, the control device 9 generates a rotational driving force in the spindle motor 6A of the tool spindle 6, causing the tool unit T1 to rotate. As a result, the gear workpiece W supported by the workpiece spindle 3 rotates in conjunction with the rotational drive of the tool unit T1. In this manner, while the gear workpiece W and the tool 10 are both rotating, the first processing blade 11B and the framing cutter 14 perform framing on the end W2 of the workpiece tooth W1. Furthermore, the second processing blade 12B adjacent to the first processing blade 11B performing framing performs relief on the corner W3 following the framing by the first processing blade 11B. In other words, the gear machining device 1 continuously repeats framing and relief processing in sequence on the workpiece tooth W1 of the gear workpiece W in one gear machining process.

[0055] 9, the first machining blade 11B of the first tool member 11 chamfers an end W2 on one side of the workpiece tooth W1 by pressing it, thereby forming a framing portion W2. The second machining blade 12B of the second tool member 12 removes the corner by pressing it while moving the machining point in a direction along the rotation axis Ct at a corner W3 circumferentially adjacent to the formed framing portion W2 of the workpiece tooth W1 on which the first machining blade 11B has formed the framing portion W2, thereby forming a relief portion W3.

[0056] Although not shown, the corner W3, i.e., the relief W3, varies depending on whether the finished gear is a drive gear or a driven gear. For example, if the finished gear is a drive gear, the relief W3 is formed in the corner W3 on the tooth base side of the work tooth W1 because the gear begins to mesh with the mating gear on the tooth base side in the radial direction of the work (see FIG. 2). On the other hand, if the finished gear is a driven gear, the relief W3 is formed in the corner W3 on the tooth tip side of the work tooth W1 because the gear begins to mesh with the mating gear on the tooth tip side in the radial direction of the work (see FIG. 2).

[0057] The framing cutter 14 chamfers the end W2 of the workpiece tooth W1 on the opposite side in the direction of the rotation axis Ct from the machining position by the first machining blade 11B and the second machining blade 12B, thereby forming the framing portion W2. The framing cutter 14 chamfers the end W2 of the workpiece tooth W1 on the opposite side in the direction of the rotation axis Ct from the machining position by the first machining blade 11B and the second machining blade 12B, thereby forming the framing portion W2.

[0058] In this way, when the tool 10 processes the workpiece tooth W1 of the gear workpiece W, the processing time can be significantly reduced compared to, for example, performing framing processing using a single framing cutter and then switching to a separate single relief cutter to perform relief processing. More specifically, when the tool 10 is used, framing processing and relief processing can be performed continuously and repeatedly without switching.

[0059] For this reason, when using the tool 10, for example, it is possible to perform both framing and relief processing in a processing time that is approximately the same as the processing time required to perform only conventional framing processing. Therefore, when using the tool 10, it is possible to improve the production efficiency of gears. Furthermore, when using the tool 10, there is no need to change stages, so there is no need to clearly distinguish between the framing process and the relief process, and there is no need to provide a dedicated processing machine for framing processing or a dedicated processing machine for relief processing.

[0060] As can be understood from the above explanation, the tool 10 comprises a first tool member 11 having a first processing blade 11B formed on the outer peripheral surface of the first tool body 11A and performing a framing process as a first process on a gear workpiece W (a gear W to be processed), which is a workpiece; and a second tool member 12 having a second processing blade 12B formed on the outer peripheral surface of the second tool body 12A and performing a relief process as a second process on the gear workpiece W. When the first tool member 11 and the second tool member 12 are combined so that the rotation axes Ct of the first tool body 11A and the second tool body 12A are coaxial, the first processing blade 11B of the first tool member 11, which is one of the processing blades of the first tool member 11 and the second tool member 12, is formed to protrude toward the second tool member 12, which is the other of the first tool member 11 and the second tool member 12, and the second processing blade 12B of the second tool member 12 is formed to be positioned at a predetermined distance in the circumferential direction from the protruding portion of the first processing blade 11B.

[0061] Here, the first processing blade 11B is formed on the outer peripheral surface of the first tool body 11A so as to be parallel to the rotation axis Ct of the disk-shaped first tool body 11A, and performs a first processing on the workpiece tooth W1 of the gear workpiece W. In addition, the second processing blade 12B is formed on the outer peripheral surface of the second tool body 12A so as to be twisted about the rotation axis Ct, and is formed with a blade length along the direction of the rotation axis Ct longer than that of the first processing blade 11B so that the processing point on the workpiece tooth W1 of the gear workpiece W is movable, and performs a second processing on the workpiece tooth W1 of the gear workpiece W.

[0062] According to this, the tool 10 can be equipped with a first processing blade 11B that performs the first processing and a second processing blade 12B that performs the second processing, which is different from the first processing and moves the processing point. The tool 10 can then continuously and repeatedly perform the first and second processing on the gear workpiece W. This eliminates the need for setup changeovers and shortens the processing time compared to when the first and second processing are performed separately on the work teeth of the gear workpiece W, i.e., when only the first processing is performed followed by only the second processing. Therefore, when the tool 10 is used, the production efficiency of gears can be improved.

[0063] Furthermore, since the tool 10 can continuously and repeatedly perform the first and second machining processes, which are different from each other, there is no need to prepare a dedicated process or machine for the first machining, or a dedicated process or machine for the second machining. Therefore, when using the tool 10, it is possible to suppress increases in production costs even when producing high-performance gears with higher load capacities.

[0064] (4. First Modification) In the above-described embodiment, an example has been given of the case where the gear machining device 1 performs relief machining on the workpiece teeth W1 of the gear workpiece W as the second machining. Alternatively, the gear machining device 1 can also perform shaving as the second machining, in which the gear machining device 1 moves the machining point relative to the tooth surface while meshing with the gear workpiece W and contacting the tooth surface, thereby removing irregularities on the tooth surface. The first modification will be described in detail below.

[0065] 10 , the tool 20 includes a first tool member 21 and a second tool member 22. The tool 20 is formed by combining the first tool member 21 and the second tool member 22. Similarly to the tool unit T1, the tool unit T2 is integrally assembled via a spacer 23 so that the tool 20 and the chamfering cutter 24 are coaxially spaced apart from each other with a gap corresponding to the tooth width of the gear workpiece W in the tooth trace direction.

[0066] In the first modified example, the first tool member 21 is a tool member that performs frazing as a first processing on the gear workpiece W, similar to the first tool member 11 of the above-described embodiment. The first tool member 21 has a disk-shaped first tool body 21A. The first tool member 21 also has a first processing blade 21B (i.e., a frazing blade) that is formed on the outer peripheral surface of the first tool body 21A and is parallel to the rotation axis Ct of the first tool body 21A and performs the frazing.

[0067] The second tool member 22 is a tool member that performs shaving as a second processing different from the first processing on the workpiece tooth W1 of the gear workpiece W. The second tool member 22 has a disk-shaped second tool body 22A that is different from the first tool body 21A. The second tool member 22 also has a second processing blade 22B that is formed on the outer peripheral surface of the second tool body 22A so as to twist with respect to the rotation axis Ct of the second tool body 22A and that performs the shaving processing.

[0068] The second cutting blade 22B has numerous serration grooves 22D on its cutting surface to remove irregularities (so-called polygonal errors) on the tooth surface of the workpiece tooth W1 while cutting. In other words, the second cutting blade 22B is a shaving blade for performing shaving. Therefore, in the first modified example, the tool 20 is formed by combining a first cutting blade 21B (fraging blade) that performs framing as the first process and a second cutting blade 22B (shaving blade) that performs shaving as the second process. The second cutting blade 22B can perform, for example, crowning, which forms a bulge in the center portion of the workpiece tooth W1 in the tooth trace direction. Furthermore, because the second cutting blade 22B can remove irregularities on the tooth surface of the workpiece tooth W1, it can also perform relief processing to remove the corners of the corners W3, as in the above-described embodiment.

[0069] Here, in the tool 20, as in the tool 10 of the above-described embodiment, the first tool body 21A and the second tool body 22A are combined so that their respective rotation axes Ct are coaxial. Also in the first modified example, the first processing blade 21B of the first tool member 21 is formed to protrude toward the second tool member 22. Therefore, in the second tool member 22, the second processing blade 22B and the removing portion 22C are formed so as to be positioned at a predetermined interval in the circumferential direction from the protruding portion 21C of the first processing blade 21B of the first tool member 21.

[0070] Next, a gear machining method will be described in which, for example, frazing and shaving are performed on a gear workpiece W (machined gear W) before heat treatment, with the gear machining apparatus 1 being equipped with a tool unit T2 including a tool 20. Specifically, in the first modified example, as in the above-described embodiment, frazing and shaving are performed in sequence and continuously in the gear machining process shown in Figure 6.

[0071] In the first modified example, as shown in Fig. 11 , the control device 9 rotates the tool spindle 6, i.e., the tool unit T2, of the gear cutting device 1 around the C-axis. That is, the control device 9 operates the swivel table 5 to rotate the tool spindle 6, i.e., the tool unit T2, around the C-axis. The magnitude of rotation of the tool spindle 6, i.e., the tool 20, around the C-axis is determined, for example, based on the magnitude of torsion of the second cutting blade 22B about the rotation axis Ct and the magnitude of torsion of the workpiece tooth W1 of the gear workpiece W about the rotation axis Cw. This allows the second cutting blade 22B to continuously contact the tooth flank of the workpiece tooth W1 in the tooth trace direction, i.e., the machining point can be moved, and irregularities on the tooth flank can be removed by the serration grooves 22D.

[0072] The control device 9 then brings the first processing blade 21B or the second processing blade 22B of the tool 20 into mesh with the workpiece tooth W1 of the gear workpiece W, and brings the chamfering cutter 24 of the tool unit T2 into mesh with the workpiece tooth W1 of the gear workpiece W. Here, even in the first modified example, the tool 20 and the chamfering cutter 24 meshed with the gear workpiece W are maintained in a state in which they press the gear workpiece W with a predetermined pressing force in the Z-axis direction. The control device 9 also makes the pair of rollers 8A of the deburring rollers 8 clamp the side surfaces of the gear workpiece W.

[0073] Next, the control device 9 generates a rotational driving force in the spindle motor 6A of the tool spindle 6 to rotate the tool unit T2. As a result, the gear workpiece W supported by the workpiece spindle 3 rotates in conjunction with the rotational drive of the tool unit T1. In this manner, while the gear workpiece W and the tool 20 are both rotating, the first processing blade 21B and the framing cutter 24 perform framing on the workpiece tooth W1. Furthermore, the second processing blade 22B adjacent to the first processing blade 21B performing the framing performs shaving after the framing by the first processing blade 21B. In other words, the gear machining device 1 of the first modified example repeatedly and continuously performs framing and shaving in the gear machining process until a predetermined machining time has elapsed.

[0074] Therefore, in the first modified example, the framing portion W2 can be formed on the workpiece tooth W1 of the gear workpiece W by framing, as in the above-described embodiment, and shaving can be performed to remove irregularities. In this case, by using the tool unit T2 including the tool 20 in the gear machining device 1, the framing and shaving can be performed continuously and repeatedly on the workpiece tooth W1 of the gear workpiece W. Therefore, the first modified example also provides the same effects as the above-described embodiment.

[0075] (5. Second Modification) Next, a second modification that is a modification of the above-described embodiment and first modification will be described. The tool 10 of the tool unit T1 in the above-described embodiment includes a first tool member 11 that performs a first machining operation (specifically, frazing) and a second tool member 12 that performs a second machining operation (specifically, relief machining), and the first tool member 11 and the second tool member 12 are combined together. In this case, the first tool member 11 has a disk-shaped first tool body 11A, and the second tool member 12 has a disk-shaped second tool body 12A.

[0076] The tool 20 of the tool unit T2 of the first modified example described above includes a first tool member 21 for performing a first processing (specifically, frazing) and a second tool member 22 for performing a second processing (specifically, shaving), and is configured to combine the first tool member 21 and the second tool member 22. In this case, the first tool member 21 has a disk-shaped first tool body 21A, and the second tool member 22 has a disk-shaped second tool body 22A.

[0077] 12 , the tool 30 constituting the tool unit T3 includes, for example, a disk-shaped tool body 31 formed by integrating the first tool body 11A and the second tool body 12A of the tool 10. That is, the tool body 31 is formed by the first tool body 11A and the second tool body 12A. Of course, the tool body 31 can also be formed by the first tool body 21A and the second tool body 22A of the tool 20.

[0078] A first processing blade 32 is formed on the outer peripheral surface of the disk-shaped tool body 31 to perform a first processing on the workpiece tooth W1 of the gear workpiece W. The first processing blade 32 is formed to be parallel to the rotation axis Ct of the tool body 31. Here, in the second modified example, a case will be exemplified in which the first processing blade 32 is a frazing blade that performs frazing as the first processing.

[0079] Furthermore, a second processing blade 33 is formed on the outer peripheral surface of the tool body 31 to perform a second processing on the workpiece tooth W1 of the gear workpiece W. The second processing blade 33 is formed to twist with respect to the rotation axis Ct of the tool body 31. The second processing blade 33 is formed to have a longer blade length along the direction of the rotation axis Ct than the first processing blade 32 so that the processing point on the workpiece tooth W1 can move. Here, the second modified example illustrates a case where the second processing blade 33 is a relief blade that performs a relief processing as the second processing. Of course, the second processing blade 33 may also be a shaving blade that performs a shaving processing as the second processing.

[0080] The first processing blade 32 and the second processing blade 33 are arranged alternately along the outer circumferential surface of the tool body 31, for example, in accordance with the spacing between the workpiece teeth W1 in the circumferential direction of the gear workpiece W, similarly to the tool 10 in which the above-described first tool member 11 and second tool member 12 are combined. Similarly to the tool unit T1, the tool unit T3 is assembled integrally via the spacer 34 so that the tool 30 and the chamfering cutter 35 are coaxial with a spacing corresponding to the tooth width in the tooth trace direction of the gear workpiece W.

[0081] The tool unit T3 equipped with the tool 30 is also mounted on the tool spindle 6 of the gear cutting device 1 and the above-mentioned gear cutting process is performed, thereby performing framing as the first process and relief or shaving as the second process on the workpiece tooth W1. That is, in the second modified example as well, the control device 9 controls the operation of the gear cutting device 1 to bring the first processing blade 32 or the second processing blade 33 of the tool 30 into mesh with the workpiece tooth W1 of the gear workpiece W, and the framing cutter 35 of the tool 30 into mesh with the workpiece tooth W1 of the gear workpiece W, as shown in Figure 13 .

[0082] In the second modified example, the control device 9 also causes the spindle motor 6A of the tool spindle 6 to generate a rotational driving force, thereby rotating the tool unit T3 pressing against the gear workpiece W. This causes the first processing blade 32 and the framing cutter 25 to perform framing on the workpiece tooth W1. Furthermore, the second processing blade 33 adjacent to the first processing blade 32 performing framing performs a relieving or shaving process following the framing process performed by the first processing blade 32. In other words, in the second modified example, the gear machining device 1 repeatedly and continuously performs the framing and the relieving or shaving processes in the gear machining process shown in FIG. 6 until a predetermined machining time has elapsed. Therefore, the second modified example also achieves the same effects as the above-described embodiment and the first embodiment.

[0083] (6. Third Modification) In the above-described embodiment, first modification, and second modification, an example has been given of a case in which the first processing blade 11B, the first processing blade 21B, and the first processing blade 32 perform framing as the first processing. In this case, as shown in FIG. 9 , the first processing blades 11B, 21B, and 32 and the framing cutters 14, 24, and 35 press the side surfaces parallel to the rotation axis Ct against the workpiece tooth W1, thereby chamfering the workpiece tooth W1 and forming the framing portion W2.

[0084] Instead, in the third modified example, as shown in Fig. 14, the first cutting blade 11B, 21B, 32 is provided with a chamfering portion 11D, a chamfering portion 21D, and a chamfering portion 32A for chamfering the workpiece tooth W1. As a result, in the third modified example, the tool 10, 20, 30 chamfers the workpiece tooth W1 by pressing the chamfering portion 11D, 21D, 32A against the workpiece tooth W1 during framing. This allows a framing portion W2 of a desired shape to be formed on the workpiece tooth W1.

[0085] 14, the chamfering cutter 14, 24, 35 is provided with chamfering portions 14A, 14B, chamfering portions 24A, 24B, and chamfering portions 35A, 35B for chamfering two adjacent workpiece teeth W1 in a gear workpiece W. As a result, in the third modification, the tool 10, 20, 30 chamfers the workpiece teeth W1 during framing by pressing the chamfering portion 14A, 24A, 35A against one of the two adjacent workpiece teeth W1 and pressing the chamfering portion 14B, 24B, 35B against the other of the two adjacent workpiece teeth W1. This makes it possible to form a framing portion W2 of a desired shape on the workpiece tooth W1 and shorten the processing time.

[0086] (7. Fourth Modification) In the third modification described above, the first processing blades 11B, 21B, 32 are provided with chamfered portions 11D, 21D, 32A on only one side, so as to perform framing on one workpiece tooth W1 of the gear workpiece W. In addition to this, as shown in Fig. 15, it is also possible to provide the first processing blades 11B, 21B, 32 with chamfered portions 11D, 11E, chamfered portions 21D, 21E, and chamfered portions 32A, 32B that chamfer two adjacent workpiece teeth W1 on the gear workpiece W. As a result, even in the fourth modification, it is possible to form a framing portion W2 of a desired shape on the workpiece tooth W1 and further shorten the processing time.

[0087] (8. Fifth Modification) In the above-described embodiment and each modification, the tool units T1, T2, and T3 are configured by assembling one tool 10, 20, or 30 and a chamfering cutter 14, 24, or 35 via the spacers 13, 23, or 34. Alternatively, the chamfering cutters 14, 24, or 35 and the spacers 13, 23, or 34 of the tool units T1, T2, or T3 may be omitted, and two tools 10, 20, or 30 may be assembled using bolts or the like. For example, as shown in FIG. 16 , a tool unit T4 can be configured by assembling two tools 10.

[0088] In this case, as shown in Fig. 17, the tool 10 constituting the tool unit T4 can be provided with a chamfered portion 11D on the first processing blade 11B in the same manner as in the third modified example described above. Furthermore, in this case, as shown in Fig. 18, the tool 10 constituting the tool unit T4 can be provided with chamfered portions 11D and 11E on the first processing blade 11B in the same manner as in the fourth modified example described above. While the fifth modified example illustrates the tool unit T4 using the tool 10, it is of course also possible to configure the tool unit using tools 20 and 30.

[0089] (9. Sixth Modification) In the above-described embodiment and each modification except for the second modification, for example, the case where the first processing blade 11B of the first tool member 11 has a protrusion 11C protruding toward the second tool member 12 has been exemplified. In addition to this, as shown in Fig. 19 , when the tool unit T5 is configured using two tools 10, the second processing blade 12B of the second tool member 12 may have, for example, a protrusion 12D protruding toward the adjacent second tool member 12 on the opposite side of the first tool member 11 along the rotation axis Ct. Furthermore, as shown in Fig. 19 , when the tool unit T5 is configured using two tools 20, the second processing blade 22B of the second tool member 22 may have, for example, a protrusion 22E protruding toward the adjacent second tool member 22 on the opposite side of the first tool member 21 along the rotation axis Ct.

[0090] In this case, the blade length of the second cutting blade 12B provided on the second tool member 12 can be increased. For example, by reducing the angle between the second cutting blade 12B and the workpiece tooth W1, the relief portion W3 can be formed larger along the tooth trace direction. In other words, by increasing the blade length of the second cutting blade 12B, the area where relief processing is performed can be expanded as needed. Furthermore, when performing shaving as the second processing, for example, by increasing the blade length of the second cutting blade 22B, the serration grooves 22D of the second cutting blade 22B can more easily contact the tooth surface of the workpiece tooth W1. This allows the tooth surface of the workpiece tooth W1 to be ground more smoothly.

[0091] In this case, the tools 10 and 20 constituting the tool unit T5 can be provided with chamfered portions 11D and 21D on the first cutting blades 11B and 21B in the same manner as in the third modified example described above, as shown in Fig. 20. In this case, the tools 10 and 20 constituting the tool unit T5 can be provided with chamfered portions 11D and 11E and chamfered portions 21D and 21E for chamfering the first cutting blades 11B and 21B in the same manner as in the fourth modified example described above, as shown in Fig. 21.

[0092] (10. Seventh Modification) In the above-described embodiment and each modification except for the second modification, the tool units T1, T2, T4, and T5 each include the tool 10 and the tool 20, which are a combination of one first tool member 11 and one second tool member 12, or one first tool member 21 and one second tool member 22. In addition to or instead of this, the tool units T1, T2, T4, and T5 may each include the tool 10 and the tool 20, which are a combination of a plurality of first tool members 11 and a plurality of second tool members 12, or a combination of a plurality of first tool members 21 and a plurality of second tool members 22. Specifically, as illustrated in FIG. 22 , the tool unit T6 may include, for example, the tool 10, which has one first tool member 11 and two second tool members 12M and 12N.

[0093] The two second tool members 12M and 12N can have different arrangements of the second machining blades 12B so that the machining positions relative to the workpiece tooth W1 are different. For example, as shown in FIG. 22 , the second machining blade 12B of the second tool member 12M is formed so that the contact angle with the workpiece tooth W1 is small. On the other hand, as shown in FIG. 22 , the second machining blade 12B of the second tool member 12N is formed so that the contact angle with the workpiece tooth W1 is large. As a result, for example, when performing relief machining, the second tool member 12M and the second tool member 12N can each relieve different corners W3 (relief portions W3) of the workpiece tooth W1, i.e., two corners W3.

[0094] As a result, according to the seventh modification, it is possible to increase the number of locations where the second machining, such as relief machining, can be performed, thereby reducing the machining time. Here, the two second tool members 12M and 12N perform the second machining, although at different machining positions. Therefore, the two second tool members 12M and 12N can be considered as a single second tool member 12. It goes without saying that the second machining is not limited to relief machining and includes the shaving machining described above.

[0095] Also in this case, as shown in Fig. 23, the tool 10 constituting the tool unit T6 can be provided with a chamfered portion 11D on the first processing blade 11B in the same manner as in the third modified example described above. Also in this case, as shown in Fig. 24, the tool 10 constituting the tool unit T6 can be provided with chamfered portions 11D, 11E on the first processing blade 11B in the same manner as in the fourth modified example described above. Although not shown in the figures, the tool 20 can also be provided with chamfered portions in the same manner.

[0096] (11. Eighth Modification) In the above-described embodiment and each modification, the cutting height of the first cutting blades 11B, 21B, 32 and the cutting height of the second cutting blades 12B, 22B, 33 are the same. However, the force required to machine the workpiece teeth W1 of the gear workpiece W, i.e., the machining force, may differ between the first machining and the second machining. As described above, the gear machining device 1 performs machining while pressing the tool spindle 6, i.e., the tools 10, 20, 30, toward the gear workpiece W so that a predetermined pressing force is generated, with the tools 10, 20, 30 meshing with the gear workpiece W. In this case, it is preferable in terms of control and configuration that the gear machining device 1 maintain a constant pressing force.

[0097] Therefore, in the eighth modified example, the cutting height of the first cutting blades 11B, 21B, 32 is made different from the cutting height of the second cutting blades 12B, 22B, 33 so that the necessary cutting force can be applied to the gear workpiece W depending on the difference between the first and second machining. That is, in the first and second machining, the cutting height of the cutting blade on the side requiring a relatively large cutting force is made higher than the cutting height of the other cutting blade.

[0098] Specifically, frazing requires a greater machining force in the radial direction of the workpiece than relief machining or shaving, which are performed along the tooth trace direction. For this reason, as shown in Figure 25, the blade height of the first cutting blades 11B, 21B, and 32 used for frazing is made higher than the blade height of the second cutting blades 12B, 22B, and 33 used for relief machining and shaving.

[0099] As a result, when the tools 10, 20, 30 in the gear cutting device 1 are pressed against the gear workpiece W in the workpiece radial direction with a constant pressing force, the processing force of the framing processing by the first processing blades 11B, 21B, 32 is relatively greater than the processing force of the relief processing and shaving processing by the second processing blades 12B, 22B, 33. Therefore, the first processing blades 11B, 21B, 32 can reliably form the framing portion W2 on the workpiece tooth W1. As for other effects, the same effects as those of the above-mentioned embodiment and each modified example can be obtained.

[0100] (12. Ninth Modification) In the above-described embodiments and each modification except for the third modification, the first tool member 11, 21 and the second tool member 12, 22 are coaxial with respect to the rotation axis Ct, that is, the central axis of the first tool body 11A, 21A and the central axis of the second tool body 12A, 22A are coaxial with respect to the rotation axis Ct.

[0101] As explained in the eighth modified example above, there are cases where the machining force required for the first machining is different from that required for the second machining. In this case, it is effective to vary the cutting edge height of some of the first machining blades 11B, 21B formed along the outer peripheral surface of the first tool body 11A, 21A or some of the second machining blades 12B, 22B formed along the outer peripheral surface of the second tool body 12A, 22A, depending on the required machining force.

[0102] Therefore, in the ninth modified example, as shown in FIG. 26 , the central axis Ot1 of the first tool body 11A, 21A and the central axis Ot2 of the second tool body 12A, 22A are offset from each other. Specifically, the central axis Ot1 of the first tool body 11A, 21A and the central axis Ot2 of the second tool body 12A, 22A are offset by a distance L. For example, as described above, framing requires a relatively greater machining force than relief machining. Therefore, in this case, the central axis Ot1 of the first tool body 11A, 21A is offset by the distance L in the Z-axis direction from the central axis Ot2 of the second tool body 12A, 22A.

[0103] In this case, the central axis Ot2 of the second tool body 12A, 22A coincides with the rotation axis Ct of the tool 10, 20. In other words, the central axis Ot1 of the first tool body 11A, 21A is eccentric from the rotation axis Ct by a distance L. It should be noted that the central axis Ot2 of the second tool body 12A, 22A does not necessarily have to coincide with the rotation axis Ct of the tool 10, 20.

[0104] As a result, when the tools 10, 20 are pressed against the gear workpiece W with a constant pressing force in the gear cutting device 1, the processing force of the framing process by the first cutting blades 11B, 21B becomes relatively greater than the processing force of the relief and shaving process by the second cutting blades 12B, 22B for each half rotation, i.e., each half cycle. In this case, if the number of teeth of the first cutting blades 11B, 21B and the number of teeth of the workpiece teeth W1 of the gear workpiece W are set to have a predetermined relationship, the first cutting blades 11B, 21B can contact all of the workpiece teeth W1 as the tools 10, 20 continue to rotate. Therefore, the first cutting blades 11B, 21B can reliably form the framing portion W2 on the workpiece teeth W1. Other effects are similar to those of the above-described embodiment and each modified example.

[0105] Here, when the central axis Ot1 of the first tool body 11A, 21A is offset by a distance L from the central axis Ot2 of the second tool body 12A, 22A, the diameter of the second tool body 12A, 22A can be set to be smaller than the diameter of the first tool body 11A, 21A by a distance 2L. In other words, the outer diameter of the first tool body 11A, 21A and the outer diameter of the second tool body 12A, 22A are different, and the outer diameter of the first tool body 11A, 21A is set to be larger than the outer diameter of the second tool body 12A, 22A.

[0106] As a result, when the central axis Ot1 of the first tool body 11A, 21A is offset by a distance L in the radial direction relative to the central axis Ot2 of the second tool body 12A, 22A, the protruding portion 11C, 21C of the first processing blade 11B, 21B on the opposite side of the eccentricity direction abuts against the outer peripheral surface of the removal portion 12C, 22C of the second tool body 12A, 22A. This makes it extremely easy to prepare for offsetting the central axis Ot1 of the first tool body 11A, 21A. Furthermore, the first processing blade 11B, 21B on the opposite side of the eccentricity direction can also perform processing.

[0107] (13. Tenth Modification) In the above-described embodiment and each modification, examples have been given of relief processing, which is a rolling process, and shaving processing, which is a cutting process, being performed as the second processing by the second processing blade 12B, 22B, 33. In particular, with regard to the second processing, the second processing blade 12B, 22B, 33 performs processing while moving the processing point relative to the workpiece tooth W1, so grinding processing can also be performed.

[0108] Therefore, in the tenth modification, a case where the second processing blade 12B, 22B, 33 has a coating layer containing abrasive grains and performs relief processing or shaving processing by grinding on the workpiece tooth W1 is particularly illustrated. Specifically, as shown in Fig. 27, the surface of the second processing blade 12B, 22B, 33 is covered with a coating layer 12E, 22F, 33C containing abrasive grains.

[0109] As a result, the second machining blades 12B, 22B, 33 rotate relative to the gear workpiece W while meshing with it, moving the contact position between the coating layers 12E, 22F, 33C and the tooth flank of the workpiece tooth W1, i.e., the machining point. As a result, the coating layers 12E, 22F, 33C grind the tooth flank of the workpiece tooth W1. Therefore, the coating layers 12E, 33C can form a relief portion W3 on the tooth flank of the workpiece tooth W1 by grinding. Furthermore, the coating layer 22F, together with the serration grooves 22D, can remove irregularities on the tooth flank of the workpiece tooth W1 while grinding. Other effects similar to those of the above-described embodiment and each modified example can be obtained.

[0110] Incidentally, while it is effective for performing grinding to have the coating layer 12E, 22F, 33C on the second processing blade 12B, 22B, 33, it is also possible for the first processing blade 11B, 21B, 32, which performs rolling, to have a coating layer. In this case, for example, the coating layer containing abrasive grains has high hardness, so that it is possible to suppress wear and abrasion of the first processing blade 11B, 21B, 32, which performs rolling.

[0111] (14. Other Modifications) In the above-described embodiment and each modification except for the third modification, the case where the number of teeth of the first processing blades 11B, 21B on the outer peripheral surface of the first tool body 11A, 21A is the same as the number of teeth of the second processing blades 12B, 22B on the outer peripheral surface of the second tool body 12A, 22A has been exemplified. Also, the case where the formation pitch of the first processing blades 11B, 21B on the outer peripheral surface of the first tool body 11A, 21A is the same as the formation pitch of the second processing blades 12B, 22B on the outer peripheral surface of the second tool body 12A, 22A has been exemplified.

[0112] As described above, the removal portions 12C, 22C are provided on the outer peripheral surfaces of the second tool bodies 12A, 22A to allow the protrusions 11C, 21C of the first processing blades 11B, 21B to penetrate. Here, the removal portions 12C, 22C are formed by removing parts of the second processing blades 12B, 22B formed on the outer peripheral surfaces of the second tool bodies 12A, 22A.

[0113] Alternatively, the number of teeth of the second processing blades 12B, 22B formed on the outer peripheral surface of the second tool body 12A, 22A may be less than the number of teeth of the first processing blades 11B, 21B formed on the outer peripheral surface of the first tool body 11A, 21A so that the protruding portions 11C, 21C of the first processing blades 11B, 21B can penetrate. In this case, the formation pitch at which the second processing blades 12B, 22B are formed on the outer peripheral surface of the second tool body 12A, 22A is preferably at least twice the formation pitch at which the first processing blades 11B, 21B are formed on the outer peripheral surface of the first tool body 11A, 21A.

[0114] This configuration reduces the number of second cutting edges 12B, 22B formed on the outer peripheral surface of the second tool body 12A, 22A, thereby increasing the spacing between the second cutting edges 12B, 22B, i.e., the formation pitch. This allows for sufficient space for the protrusions 11C, 21C to penetrate. In particular, if the formation pitch of the second cutting edges 12B, 22B is at least twice the formation pitch of the first cutting edges 11B, 21B, the first cutting edges 11B, 21B and the second cutting edges 12B, 22B can be arranged at equal intervals in the circumferential direction with the protrusions 11C, 21C inserted, as in the above-described embodiment. Therefore, it is not necessary to remove a portion of the second cutting edges 12B, 22B formed on the outer peripheral surface of the second tool body 12A, 22A to form the removed portions 12C, 22C.

[0115] Furthermore, in the above-described embodiment and each modified example, the first processing blades 11B, 21B, 32 and the second processing blades 12B, 22B, 33 in the tools 10, 20, 30 are alternately arranged one by one. Alternatively, for example, in the case of the tool 10, the tool 10 can have a first processing blade group consisting of a plurality of first processing blades 11B arranged continuously along the outer circumferential surface of the first tool body 11A, and a second processing blade group consisting of at least one second processing blade 12B arranged along the outer circumferential surface of the second tool body 12A. This allows the arrangement of the first processing blades 11B, 21B, 32 and the second processing blades 12B, 22B, 33 to be freely set depending on the first processing and the second processing.

[0116] In the above-described embodiment and each modified example, relief processing and shaving processing are exemplified as the second processing. The second processing is not limited to relief processing, which is a rolling processing, or shaving processing, which is a cutting processing, and various processing can be adopted, particularly as long as the processing point is moved. For example, tooth surface finishing processing can be exemplified. In this case, a finishing cutter can be used as the second processing blade.

[0117] Furthermore, in the above-described embodiment and each modified example, the tool 10 (i.e., the tool spindle 6) in the gear machining apparatus 1 is capable of linear movement in the Z-axis direction toward the gear workpiece W, and the deburring roller 8 is capable of linear movement in the X-axis direction toward the gear workpiece W. Furthermore, in the above-described embodiment and each modified example, the gear machining apparatus 1 is configured to rotate the tool spindle 6 around the C-axis with the workpiece spindle 3 as the reference, using the swivel table 5 provided on the Z-axis moving table 4.

[0118] However, in the gear machining apparatus 1, the configuration for relatively moving the gear workpiece W and the tool 10 can be modified as appropriate. For example, in the gear machining apparatus 1, the tool 10 (i.e., the tool spindle 6) can be made to move linearly toward the gear workpiece W in the X-axis direction, and the deburring roller 8 can be made to move linearly toward the gear workpiece W in the Z-axis direction. Furthermore, the gear machining apparatus 1 can also be made to move the gear workpiece W (i.e., the workpiece spindle 3) linearly toward the tool 10 (i.e., the tool spindle 6) in the Z-axis direction or the X-axis direction. Furthermore, the gear machining apparatus 1 can also be configured so that the workpiece spindle 3 is used as a reference and the tool spindle 6 is rotated around the A-axis, which is a rotation axis around the X-axis in a reference state. Furthermore, the gear machining apparatus 1 can also be configured so that the workpiece spindle 3 is used as a reference and the workpiece spindle 3 is rotated around the C-axis or the A-axis, using the tool spindle 6 as a reference.

[0119] Furthermore, in the above-described embodiment and each modified example, the workpiece spindle 3 is used as a free rotation axis and the tool spindle 6 is rotationally driven in the gear machining device 1. Alternatively, the gear machining device 1 can be configured such that the workpiece spindle 3 is rotationally driven and the tool spindle 6 is used as a free rotation axis.

[0120] Furthermore, in the above-described embodiment and each modified example, framing, relief, and shaving are performed on an external gear workpiece W having workpiece teeth W1 formed on its outer peripheral surface. However, shaving, in particular, can also be performed on an internal gear workpiece W having workpiece teeth formed on its inner peripheral surface by internal tooth shaving.

[0121] Here, the first form of tool of the present invention is a tool having a plurality of machining blades, including a first machining blade formed on the outer surface of the tool body so as to be parallel to the rotation axis of the disk-shaped tool body and performing a first machining on the workpiece, and a second machining blade formed on the outer surface so as to be twisted about the rotation axis and having a blade length along the direction of the rotation axis longer than the first machining blade so that the machining point on the workpiece can be moved and performing a second machining on the workpiece, and the first machining blades and second machining blades are arranged alternately along the outer surface.

[0122] A second form of the tool of the present invention is the tool of the first form described above, wherein the tool body is formed of a disk-shaped first tool body and a disk-shaped second tool body, and comprises a first tool member formed on the outer peripheral surface of the first tool body and having a first processing blade for performing a first processing on the workpiece, and a second tool member formed on the outer peripheral surface of the second tool body and having a second processing blade for performing a second processing on the workpiece, and when the first tool member and the second tool member are combined so that the rotation axes of the first tool body and the second tool body are coaxial, one of the processing blades of the first tool member and the second tool member is formed to protrude toward the other of the first tool member and the second tool member, and the other processing blade is formed to be positioned at a predetermined distance in the circumferential direction from the protruding portion of one processing blade.

[0123] The tool of the second form of the present invention is a tool having a plurality of machining blades, and is composed of a first tool member having a first machining blade formed on the outer peripheral surface of a disk-shaped first tool body for performing a first machining operation on a workpiece, and a second tool member having a second machining blade formed on the outer peripheral surface of a disk-shaped second tool body different from the first tool body for performing a second machining operation on the workpiece. When the first tool member and the second tool member are combined so that the rotation axes of the first tool body and the second tool body are coaxial, one of the machining blades of the first tool member and the second tool member may be formed to protrude toward the other of the first tool member and the second tool member, and the other machining blade may be formed to be positioned at a predetermined circumferential distance from the protruding portion of one of the machining blades.

[0124] Furthermore, a third form of tool of the present invention is the tool of the second form described above, in which one side has a protruding portion formed so that at least a part of the processing blade protrudes toward the other side, and the other side has a removal portion from which at least a part of the processing blade has been removed, and when the first tool member and the second tool member are combined, the protruding portion enters the removal portion.

[0125] Furthermore, in a fourth form of the tool of the present invention, in the tool of the third form described above, the forming pitch at which the first processing blade is formed on the first tool member is the same as the forming pitch at which the second processing blade is formed on the second tool member.

[0126] In addition, in a tool of a fifth aspect of the present invention, the number of teeth of the other processing blade in the tool of the second aspect is smaller than the number of teeth of the one processing blade.

[0127] In a sixth aspect of the present invention, in the tool of the fifth aspect, the forming pitch at which the cutting edges are formed on the other side is at least twice the forming pitch at which the cutting edges are formed on the one side.

[0128] A seventh aspect of the present invention is a tool according to any one of the second to sixth aspects, wherein the central axis of one of the first and second tool members is eccentric with respect to the central axis of the other of the first and second tool members.

[0129] In addition, the tool of an eighth aspect of the present invention is the tool of the seventh aspect, wherein the outer diameter of the first tool body of the first tool member is different from the outer diameter of the second tool body of the second tool member.

[0130] A tool according to a ninth aspect of the present invention is the tool according to the eighth aspect, wherein the outer diameter of the first tool body is larger than the outer diameter of the second tool body.

[0131] Furthermore, a tool of a tenth aspect of the present invention is a tool of any one of the first to ninth aspects, in which the first processing blade and the second processing blade have different cutting heights, which represent the height from the base of the blade to the tip of the blade.

[0132] Furthermore, the tool of an eleventh aspect of the present invention is the tool of the tenth aspect, wherein the cutting edge height of one of the first processing blade and the second processing blade is greater than the cutting edge height of the other of the first processing blade and the second processing blade.

[0133] Furthermore, a twelfth form of the tool of the present invention is a tool according to any one of the first to eleventh forms, wherein the workpiece is a gear to be processed, the first processing blade is a framing blade that meshes with the gear to be processed and presses an end of the tooth flank of the gear to be processed in the tooth trace direction to perform a framing process as a first processing step, thereby chamfering the end, and the second processing blade is a relief blade that meshes with the gear to be processed and presses one of the four corners of the tooth flank in the tooth trace direction while moving a processing point relative to the tooth flank of the gear to perform a relief process to remove the corner of the corner.

[0134] Furthermore, a thirteenth form of the tool of the present invention is a tool according to any one of the first to twelfth forms, in which the workpiece is a gear to be machined, the first machining blade is a framing blade that meshes with the gear to be machined and presses the end of the tooth flank of the gear to be machined in the tooth trace direction to perform a framing process as a first process, and the second machining blade is a shaving blade that meshes with the gear to be machined and moves a machining point relative to the tooth flank while contacting the tooth flank to perform a shaving process as a second process, removing irregularities on the tooth flank.

[0135] Furthermore, a tool of a fourteenth aspect of the present invention is a tool of any one of the first to thirteenth aspects, wherein the surface of the first processing blade and at least the second processing blade of the second processing blade is covered with a coating layer containing abrasive grains.

[0136] Furthermore, a tool of a fifteenth form of the present invention is a tool of any one of the first form to the fourteenth form, which has a first cutting blade group consisting of a plurality of first cutting blades arranged continuously along the outer peripheral surface, and a second cutting blade group consisting of at least one second cutting blade along the outer peripheral surface.

[0137] 1... gear machining device, 2... base, 3... work spindle, 4... Z-axis moving table (moving device), 5... turning table (moving device), 6... tool spindle, 6A... spindle motor, 7... X-axis moving table, 8... deburring roller, 8A... pair of rollers, 9... control device, 10... tool, 11... first tool member, 11A... first tool body, 11B... first processing blade (frazing blade), 11C... protrusion, 11D... chamfering portion, 11 E... chamfered portion, 12... second tool member, 12A... second tool body, 12B... second processing blade (relief blade), 12C... removal portion, 12D... protruding portion, 12E... coating layer, 13... spacer, 14... frazing cutter, 14A... chamfered portion, 14B... chamfered portion, 20... tool, 21... first tool member, 21A... first tool body, 21B... first processing blade (frazing blade), 21C... protruding portion, 21D... chamfered portion , 21E... chamfered portion, 22... second tool member, 22A... second tool body, 22B... second processing blade (shaving blade), 22C... removal portion, 22D... serration groove, 22E... protrusion, 22F... coating layer, 23... spacer, 24... framing cutter, 24A... chamfered portion, 24B... chamfered portion, 30... tool, 31... tool body, 32... first processing blade (fraging blade), 32A... chamfered portion, 32B... Chamfered portion, 33...second processing blade (relief blade, shaving blade), 34...spacer, 35...fraging cutter, 35A...chamfered portion, 35B...chamfered portion, W...gear work (gear to be processed (workpiece)), W1...workpiece tooth, W2...fraging portion (end portion), W3...relief portion (corner portion), Ct, Cw, Cr...rotation axis, Ot1, Ot2...center axis, T1, T2, T3, T4, T5, T6...tool unit

Claims

1. A tool having a plurality of machining blades, comprising: a first machining blade formed on the outer peripheral surface of a disk-shaped tool body so as to be parallel to the rotation axis of the tool body and performing a first machining operation on a workpiece; and a second machining blade formed on the outer peripheral surface so as to be twisted about the rotation axis and having a blade length along the direction of the rotation axis longer than that of the first machining blade so that a machining point on the workpiece can be moved and performing a second machining operation on the workpiece, wherein the first machining blade and the second machining blade are arranged alternately along the outer peripheral surface.

2. The tool according to claim 1, wherein the tool body is formed of a disk-shaped first tool body and a disk-shaped second tool body, and comprises: a first tool member having the first processing blade formed on the outer peripheral surface of the first tool body and performing the first processing on the workpiece; and a second tool member having the second processing blade formed on the outer peripheral surface of the second tool body and performing the second processing on the workpiece, and wherein, in a state in which the first tool member and the second tool member are combined so that the rotation axes of the first tool body and the second tool body are coaxial, one of the processing blades of the first tool member and the second tool member is formed to protrude toward the other of the first tool member and the second tool member, and the other processing blade is formed to be positioned at a predetermined interval in the circumferential direction from the protruding portion of the one processing blade.

3. A tool as described in claim 2, wherein the one of the tool members has a protruding portion formed so that at least a portion of the processing blade protrudes toward the other of the tool members, and the other of the tool members has a removal portion from which at least a portion of the processing blade has been removed, and when the first tool member and the second tool member are combined, the protruding portion enters the removal portion.

4. The tool according to claim 3, wherein the forming pitch at which the first machining blade is formed on the first tool member is the same as the forming pitch at which the second machining blade is formed on the second tool member.

5. The tool according to claim 2, wherein the number of teeth of the other cutting blade is less than the number of teeth of the one cutting blade.

6. The tool according to claim 5, wherein the forming pitch at which the cutting edges are formed on the other side is at least twice the forming pitch at which the cutting edges are formed on the one side.

7. The tool of claim 2, wherein a central axis of one of said first and second tool members is disposed eccentrically relative to a central axis of the other of said first and second tool members.

8. The tool of claim 7, wherein an outer diameter of the first tool body of the first tool member and an outer diameter of the second tool body of the second tool member are different.

9. The tool of claim 8, wherein an outer diameter of the first tool body is greater than an outer diameter of the second tool body.

10. The tool according to claim 1, wherein the first processing blade and the second processing blade have different blade heights, which represent the height from the base of the blade to the tip of the blade.

11. The tool of claim 10, wherein the edge height of one of the first work blade and the second work blade is greater than the edge height of the other of the first work blade and the second work blade.

12. The tool described in claim 1, wherein the workpiece is a gear to be processed, the first processing blade is a framing blade which performs, as the first processing, a framing process by meshing with the gear to press an end portion of the tooth flank of the gear to be processed in the tooth trace direction to chamfer the end portion, and the second processing blade is a relief blade which performs, as the second processing, a relief process by meshing with the gear to be processed and pressing one of the four corners of the tooth flank in the tooth trace direction while moving a processing point relative to the tooth flank of the gear to remove the corner of the one corner portion.

13. A tool as described in claim 1, wherein the workpiece is a gear to be processed, the first machining blade is a framing blade which performs, as the first machining, a framing process by meshing with the gear to be processed and pressing an end of the tooth flank of the gear to be processed in the tooth trace direction to chamfer the end, and the second machining blade is a shaving blade which performs, as the second machining, a shaving process by meshing with the gear to be processed and contacting the tooth flank while moving a machining point relative to the tooth flank to remove irregularities on the tooth flank.

14. The tool according to claim 1, wherein the first processing blade and at least the second processing blade of the second processing blade are covered on their surfaces with a coating layer containing abrasive grains.

15. The tool of claim 1, comprising: a first cutting edge group consisting of a plurality of the first cutting edges arranged continuously along the outer circumferential surface; and a second cutting edge group consisting of at least one of the second cutting edges arranged along the outer circumferential surface.

16. A gear machining device comprising: the tool according to any one of claims 1 to 15; a tool spindle which rotationally drives the tool; a work spindle which rotationally drives a gear to be machined as the workpiece; and a moving device which moves the work spindle and the tool spindle relatively so that the tool supported by the tool spindle and the gear to be machined supported by the work spindle can mesh with each other, wherein the first machining and the second machining are repeatedly performed in one machining step.

17. A gear machining device as set forth in claim 16, wherein the second machining blade for performing the second machining has a surface covered with a coating layer containing abrasive grains and grinds the tooth surface of the gear to be machined.

18. A gear machining method comprising: the tool according to any one of claims 1 to 15; a tool spindle which rotationally drives the tool; a work spindle which rotationally drives a gear to be machined as the workpiece; and a moving device which moves the work spindle and the tool spindle relatively so that the tool supported by the tool spindle and the gear to be machined supported by the work spindle can mesh with each other, wherein in one machining step, the second machining is performed following the first machining, and the first machining is performed following the second machining, thereby repeatedly performing the first machining and the second machining in that order.

19. A gear machining method as set forth in claim 18, wherein the second machining blade performing the second machining has a surface covered with a coating layer containing abrasive grains and grinds the tooth surface of the gear to be machined.

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