JP2020069623A - Processing device and method for gear-cutting tool - Google Patents

Abstract

To provide a device and a method for easily and efficiently processing a gear cutting tool for skiving.SOLUTION: A processing device 10 for a gear cutting tool 2 is formed into an external gear shape, has an abrasive wheel 1 having an external tooth as a grinding part and carries out the grinding operation for the gear cutting tool 2 having plural teeth 2a on a peripheral face and used for skiving. The circumferential cross-sectional shapes of the abrasive wheel 1 in the grinding part are formed into those for at least grinding before and after finishing. The processing device 10 comprises: a rotation control part rotating the abrasive wheel 1 around the center axis X1 thereof and also rotating the gear cutting tool 2 around the center axis X2 thereof with the center axis X1 of the abrasive wheel 1 and the center axis X2 of the gear cutting tool 2 intersecting and inclined at a crossing angle; and a movement control part relatively moving the abrasive wheel 1 in a center axis X2 direction to continuously carry out tooth grinding before and after finishing at the grinding part.SELECTED DRAWING: Figure 1A

Description

  The present invention relates to a machining device and a machining method for a gear cutting tool.

  A gear cutting tool for cutting a cutting object to create a gear is formed in a shape based on the shape of the gear. When the cutting edge of the gear cutting tool is worn, dressing is performed. For example, Patent Document 1 describes a method of dressing an internal gear type grinding wheel (a gear cutting tool) with an external gear type dresser. Further, Patent Document 2 describes a dressing method for a pinion cutter (a gear cutting tool).

  By the way, in recent years, gear cutting capable of high-speed cutting has been desired from the viewpoint of cost, and skiving processing as described in Patent Document 3 is known. Skiving is a state in which the center axis of the gear cutting tool and the center axis of the cutting target are tilted (a state where there is a crossing angle in gear cutting), and the gear cutting tool and the cutting target are synchronized around each center axis. This is a process of relatively moving the gear cutting tool in the direction of the central axis of the object to be cut while rotating. An external gear type is generally used as a gear cutting tool for skiving. When the cutting edge of the external gear type gear cutting tool is worn, dressing is performed with a disc type grinding wheel.

JP-A-8-252768 Japanese Patent No. 4763611 JP 2012-171020 A

  When the object to be processed is an external gear, an internal gear type, which has a smaller processing load and is less likely to wear than an external gear type, is desirable as a gear cutting tool for skiving. However, if the cutting edge of the internal gear type gear cutting tool is worn, dressing with a disk type grinding wheel may cause the disk type grinding wheel to interfere with the support member (chuck etc.) that supports the gear cutting tool. There is. Further, in the dressing of this gear cutting tool, it is necessary to perform a pre-finishing process and a finishing process in order to ensure dimensional accuracy, and the takt time tends to be long. This problem exists not only when dressing an internal gear type gear cutting tool (machining a gear cutting tool) but also when manufacturing an internal gear type gear cutting tool (machining a gear cutting tool). .. The same applies to the external gear type gear cutting tool.

  An object of the present invention is to provide a machining device and a machining method for a gear cutting tool that can easily and efficiently process a gear cutting tool for skiving.

  A machining device for a gear cutting tool according to the present invention is a gear cutting tool that is formed in an external gear shape and has a grinding wheel with external teeth as a grinding portion, and that is used for skiving processing having a plurality of blades on a peripheral surface. As a grinding target, there is provided a processing device for a gear cutting tool that grinds the gear cutting tool with the grinding wheel, wherein the grinding wheel has at least a cross-sectional shape in the circumferential direction of the grinding wheel in the grinding section for pre-finish grinding. And formed for finish grinding, in a state in which the central axis of the grinding wheel and the central axis of the gear cutting tool are orthogonal to each other in a state of being inclined by a crossing angle, the grinding wheel around the central axis of the grinding wheel While rotating, the rotation control unit for rotating the gear cutting tool around the central axis of the gear cutting tool, and the grinding wheel is relatively moved in the central axis direction of the gear cutting tool, the blade in the grinding unit. Before finishing and grinding Comprises a movement control unit for performing finish grinding continuously, the

  A method of processing a gear cutting tool according to the present invention is a gear cutting tool formed in an external gear shape, having a grinding wheel with external teeth as a grinding portion, and used for skiving having a plurality of blades on a peripheral surface. As a grinding target, there is provided a method of processing a gear cutting tool for grinding the gear cutting tool with the grinding wheel, wherein the grinding wheel has at least a cross-sectional shape in the circumferential direction of the grinding wheel in the grinding section for pre-finish grinding. And formed for finish grinding, in a state in which the central axis of the grinding wheel and the central axis of the gear cutting tool are orthogonal to each other in a state of being inclined by a crossing angle, the grinding wheel around the central axis of the grinding wheel While rotating, the rotation control step of rotating the gear cutting tool around the central axis of the gear cutting tool, and relatively moving the grinding wheel in the central axis direction of the gear cutting tool, the blade in the grinding unit. Pre-finish grinding Fine finish grinding includes a movement controlling step performed continuously, the.

  According to the machining device and the machining method for a gear cutting tool according to the present invention, the center axis of the grinding wheel and the center axis of the gear cutting tool are in a state of being inclined by a crossing angle, so that the grinding wheel and the gear cutting tool are supported. It is possible to prevent interference with a supporting member or the like that operates. Since the cross-sectional shape of the grinding portion is formed for pre-finishing and for finishing, pre-finishing grinding and finish grinding can be continuously performed, and the tact time can be shortened. Therefore, the gear cutting tool for skiving can be processed easily and efficiently.

It is an outline of a processing device of a gear cutting tool, and is a perspective view showing a state of grinding a gear cutting tool with a grinding wheel. It is the figure which looked at the processing apparatus of Drawing 1A from the IB direction. It is a figure which shows the detail of the control apparatus of the processing apparatus of FIG. 1A. It is a flow chart for explaining the first half of the processing method of a gear cutting tool. It is a flow chart for explaining the second half of the processing method of a gear cutting tool. It is a perspective view which shows the grinding wheel for grinding a gear cutting tool. It is the figure which looked at the grinding part of the grindstone of Drawing 4A in the direction of the central axis. It is the figure which looked at the grinding wheel of FIG. 4B from the IVC direction. It is the figure which looked at the grinding wheel of FIG. 4B from the IVD direction. It is a perspective view showing a gear cutting tool for cutting a gear. It is the figure which looked at the blade of the gear cutting tool of Drawing 5A in the peripheral direction. It is the figure which looked at the blade of the gear cutting tool of Drawing 5A in the diameter direction. It is a perspective view of the gearwheel as a cutting target of a gear cutting tool. It is a perspective view which shows the state which cuts a gear with a gear cutting tool with the processing apparatus of FIG. 1A. It is a figure which shows the relationship between the grinding part of the grinding wheel and the blade of a gear cutting tool for explaining the processing method of a gear cutting tool. It is a figure which shows another example of the grinding part of a grinding wheel corresponding to FIG. 4C.

(1. Configuration of gear cutting tool processing device)
With reference to FIGS. 1A and 1B, a processing device 10 (grinding machine) that performs processing (dressing, manufacturing, etc.) of a gear cutting tool 2 for cutting a gear 3 (see FIG. 6) in a grinding wheel 1 will be described. .. In the present embodiment, the processing device 10 is, for example, a machining center. In particular, a 5-axis machining center having three orthogonal axes and two rotation axes in addition to the main spindle that supports the gear cutting tool 2 is applied.

  The processing apparatus 10 includes a spindle unit 11 that is movable in three orthogonal directions on a bed (not shown), and a grinding wheel 1 attached to the tip of the spindle unit 11. Therefore, the grinding wheel 1 can rotate around the central axis X1 (θ1) of the grinding wheel 1 and can move in three orthogonal directions with respect to the bed.

  Further, the processing device 10 includes a rotary table 12 that supports the gear cutting tool 2 as a cutting target. The rotary table 12 rotatably supports the gear cutting tool 2 via the chuck 13 around the central axis X2 (θ22) of the gear cutting tool 2. The rotary table 12 is provided so as to be swingable (tiltable) around one axis different from the rotary axis of the rotary table 12 with respect to the bed. That is, the rotary table 12 supports the gear cutting tool 2 so as to be tiltable.

  Further, the processing device 10 includes a control device 20. As shown in FIG. 2, the control device 20 includes a rotation control unit 21 and a movement control unit 22. The rotation control unit 21 rotates the grinding wheel 1 provided in the main spindle unit 11 around the central axis X1 (θ1) and rotates the gear cutting tool 2 provided in the rotary table 12 around the central axis X2 (θ22). ) The rotation drive motor (not shown) is controlled to rotate. Further, it drives and controls a rotary drive motor (not shown) for tilting the rotary table 12.

  The movement control unit 22 sets the spindle unit 11 to the central axis X2 direction (M31) of the gear cutting tool 2, the radial direction (M32) of the gear cutting tool 2, and the rotational tangential direction (translational direction) of the gear cutting tool 2 (M33). ) Drive control of a ball screw mechanism and a drive motor which are not shown.

  The processing apparatus 10 having such a configuration performs processing (dressing, manufacturing, etc.) of the gear cutting tool 2 with the grinding wheel 1 by the same operation as skiving processing. That is, as shown in FIG. 1, by positioning the spindle unit 11 and the rotary table 12, the central axis X1 of the grinding wheel 1 and the central axis X2 of the gear cutting tool 2 are positioned so as to have an intersection angle η. The intersection angle η is adjusted according to the twist angle β of the gear cutting tool 2 (see FIG. 5B). In this example, the twist angle β and the crossing angle η are the same.

  In this state, the grinding wheel 1 is rotated around the central axis X1 (θ1), and the gear cutting tool 2 is rotated around the central axis X2 (θ22) in synchronization with the rotation of the grinding wheel 1. Then, the grinding wheel 1 is relatively moved in the direction of the central axis X2 of the gear cutting tool 2. In this way, the gear cutting tool 2 is formed.

(2. Outline of grinding wheel, gear cutting tool and gear shape)
Here, the outline of the shapes of the grinding wheel 1, the gear cutting tool 2, and the gear 3 will be described with reference to the drawings. As shown in FIG. 4A, the grinding wheel 1 is formed in the shape of an external gear and has the external teeth as the grinding portion 1a. That is, the grinding wheel 1 includes a plurality of grinding portions 1a on the peripheral surface around the central axis X1. The grinding part 1a of the grinding wheel 1 grinds the blade 2a (see FIG. 5A) of the gear cutting tool 2 with the gear cutting tool 2 as a grinding target.

  As shown in FIG. 4B, when the grinding portion 1a is viewed in the direction of the central axis X1 from the one end surface 1A (end surface opposite to the spindle unit 11 side) side of the grinding wheel 1, the grinding portion 1a includes the gear cutting tool 2 Although it is formed in a shape corresponding to the shape of the blade groove of, in this example, it is formed in the same shape as the involute curve shape. The grinding portion 1a has a top surface 1aa, a left side surface 1ab and a right side surface 1ac.

  Then, as shown in FIG. 4C, when the grinding portion 1a is viewed in the IVC direction of FIG. 4B (the radial direction of the grinding wheel 1), the top surface 1aa of the grinding portion 1a is formed in a substantially rectangular shape, and the grinding portion 1a is formed. Between the left side surface 1ab and the right side surface 1ac is formed in a barrel shape in which the center in the direction of the central axis X1 swells to both sides in the circumferential direction of the grinding wheel 1.

  Specifically, the circumferential wall thickness of the grinding wheel 1 between the left side surface 1ab and the right side surface 1ac of the grinding portion 1a is linear from the one end surface 1A of the grinding wheel 1 toward the central axis X1 direction to the vicinity of the center. After increasing and increasing / decreasing in an arc shape near the center, it linearly decreases from the vicinity of the center in the direction of the central axis X1 to the other end surface 1B of the grinding wheel 1.

  That is, as shown in FIGS. 4B and 4C, the wall thickness on the other end surface 1B (end surface on the spindle unit 11 side) side of the grinding wheel 1 between the left side surface 1ab and the right side surface 1ac of the grinding section 1a is the left side of the grinding section 1a. It is the same as the wall thickness on the one end face 1A side of the grinding wheel 1 between the face 1ab and the right face 1ac, and becomes the minimum wall thickness ta. Further, the center wall thickness of the one end surface 1A and the other end surface 1B of the grinding wheel 1 between the left side surface 1ab and the right side surface 1ac of the grinding portion 1a becomes the maximum wall thickness tb.

  The cross-sectional shape Sa of the minimum wall thickness ta portion indicated by the alternate long and short dash line on the one end surface 1A side and the other end surface 1B side of the grinding wheel 1 between the left side surface 1ab and the right side surface 1ac of the grinding portion 1a is the same as that of the gear cutting tool 2. It is formed for pre-finishing grinding when grinding the blade 2a. The cross-sectional shape Sb of the maximum wall thickness tb indicated by the two-dot chain line at the center between the one end surface 1A and the other end surface 1B of the grinding wheel 1 between the left side surface 1ab and the right side surface 1ac of the grinding portion 1a is the gear cutting tool 2 It is formed for finish grinding when grinding the blade 2a.

  That is, the blade 2a of the gear cutting tool 2 starts pre-finishing grinding with the sectional shape Sa on the one end face 1A side of the grinding wheel 1 in the grinding portion 1a of the grinding wheel 1 and finishes the final blade shape with the central sectional shape Sb. Is finished and ground. The pre-finishing grinding may be started with the sectional shape Sa on the other end surface 1B side, and the final blade shape may be ground with the central sectional shape Sb. As a result, the blade 2a of the gear cutting tool 2 can be ground when the grinding wheel 1 moves forward and backward with respect to the gear cutting tool 2, so that the grinding efficiency can be improved.

  The reason for increasing or decreasing the wall thickness in an arc shape in the vicinity of the center of the one end surface 1A and the other end surface 1B of the grinding wheel 1 between the left side surface 1ab and the right side surface 1ac of the grinding portion 1a is that the abrasive grains fall off when grinding at the corners. This is because the machining accuracy is deteriorated due to the occurrence of the phenomenon, but when the grinding is performed on the surface, the removal of the abrasive grains can be suppressed and the processing accuracy can be maintained.

  The shape of the ground portion 1a shown in FIG. 4B viewed in the direction of the central axis X1 can be obtained by changing the dislocation coefficient, but it may be changed to a similar shape. Then, as shown in FIG. 4C, an angle δ formed by a straight line Lab extending from a side surface contour of the grinding portion 1a in the direction of the central axis X1 and a straight line L1 parallel to the central axis X1 is referred to as a side clearance angle. The side clearance angle δ may not be provided on the left side surface 1ab and the right side surface 1ac of the grinding portion 1a.

  Then, as shown in FIG. 4D, when the grinding portion 1a is viewed in the circumferential direction of the grinding wheel 1, the top surface 1aa of the grinding portion 1a is formed in a circular arc shape that is convex outward in the radial direction of the grinding wheel 1. It Specifically, the top surface 1aa of the grinding portion 1a increases in height from the one end surface 1A of the grinding wheel 1 toward the center in the direction of the central axis X1 and from the top surface 1aa to the groove surface 1ad. The height of the ground surface 1aa of the grinding portion 1a decreases from the vicinity of the center toward the other end surface 1B of the grinding wheel 1 in the direction of the central axis X1 and from the top surface 1aa to the groove surface 1ad.

  That is, the length from the top surface 1aa of the grinding wheel 1 on the other end surface 1B side to the groove surface 1ad on the top surface 1aa of the grinding portion 1a is determined from the top surface 1aa of the grinding portion 1a on the one end surface 1A side of the grinding wheel 1 to the groove surface. It is the same as the length up to 1ad and has the minimum length ha. Further, the height from the central top surface 1aa to the groove surface 1ad in the top surface 1aa of the grinding portion 1a is the maximum height hb.

  The reason why the top surface 1aa of the grinding portion 1a is hung on both sides in the direction of the central axis X1 is that the grinding portion 1a does not interfere with the grinding tool 1a from entering the blade groove of the gear cutting tool 2 to exiting. This is because The angle ε formed by the tangent line Lac at the end point Q on the one end face 1A side in the top surface contour of the grinding portion 1a in the direction of the central axis X1 and the straight line L11 parallel to the central axis X1 is called the front clearance angle. The front clearance angle ε may not be provided on the top surface 1aa of the grinding portion 1a.

  As shown in FIG. 5A, the shape of the gear cutting tool 2 to be ground by the grinding wheel 1 has a plurality of blades 2a on the inner peripheral surface around the central axis X2 of the annular member. The gear cutting tool 2 includes a rake face 2b on the end face in the direction of the central axis X2. The rake face 2b may be tapered with the center axis X2 of the gear cutting tool 2 as the center, or may be formed in a face shape that faces different directions for each blade 2a.

  Then, as shown in FIG. 5B, when the blades 2a are viewed in the circumferential direction of the gear cutting tool 2, the top surfaces 2aa of the plurality of blades 2a are formed by the top surfaces 2aa and a straight line L2 parallel to the central axis X2. It is a front flank having a clearance angle α. In this case, the distance from the central axis X2 of the gear cutting tool 2 on the cutting edge surface gradually increases as it goes from the one end surface 2b of the cutting edge 2a toward the cutting edge 2f (see FIG. 5C).

  Further, as shown in FIG. 5C, when the blades 2a are viewed in the radial direction of the gear cutting tool 2, the plurality of blades 2a have a straight line L21 whose blade line 2f direction (equal to the blade groove direction) is parallel to the central axis X2. Has a helix angle β with respect to. However, the helix angle β of the blade 2a differs depending on the helix angle of the teeth 3a of the gear 3 and the intersection angle η between the gear 3 and the gear cutting tool 2 in the cutting process. Therefore, the blade 2a may not have the helix angle β. In this example, the twist angle β and the crossing angle η are the same. The right side surface 2ab and the left side surface 2ac of the plurality of blades 2a are side clearance surfaces each having a side clearance angle γ formed by the right side surface 2ab and the left side surface 2ac and a straight line L21 parallel to the central axis X2.

  As shown in FIG. 6, the gear 3 to be cut by the gear cutting tool 2 has a plurality of teeth 3a on the peripheral surface around the central axis X3. In this embodiment, the gear 3 is a spur gear as an example, but various gears such as a helical gear can be applied.

  Since the machining of the gear 3 (creation of the teeth 3a) can be performed by skiving by the machining device 10 shown in FIG. 1, it will be briefly described. As shown in FIG. 7 corresponding to FIG. 1, the spindle unit 11 is capable of rotating the gear cutting tool 2 through the chuck 14 around the central axis X2 of the gear cutting tool 2 (θ21) and with respect to the bed. It is supported so as to be movable in three orthogonal directions. The turntable 12 supports the gear 3 rotatably and tiltably around the central axis X3 of the gear 3 (θ3).

  Then, by positioning the spindle unit 11 and the rotary table 12, the central axis X2 of the gear cutting tool 2 and the central axis X3 of the gear 3 are positioned so as to have an intersecting angle. In this state, the gear cutting tool 2 is rotated around the central axis X2 (θ21), and the gear 3 is synchronously rotated around the central axis X3 (θ3). Then, the gear cutting tool 2 is relatively moved in the direction of the central axis X3 of the gear 3. In this way, the gear 3 is formed.

(3. Operation of control device of machining device for gear cutting tool)
Next, the operation (processing method) of the control device 20 of the processing device 10 for the gear cutting tool 2 will be described with reference to FIGS. 3A, 3B and 8. The grinding wheel 1 shown in FIG. 4A is attached to the tip of the spindle unit 11 by a tool changing device. Further, the gear cutting tool 2 shown in FIG. 5A is assumed to be supported by the rotary table 12. Then, in the processing device 10 of the gear cutting tool 2, the gear cutting tool 2 is dressed by the grinding wheel 1.

  The control device 20 moves the grinding wheel 1 to the rake face 2b side of the gear cutting tool 2 so that the central axis X1 of the grinding wheel 1 and the central axis X2 of the gear cutting tool 2 have a crossing angle η. Positioning is performed (step S1 in FIG. 3A). In this state, the grinding wheel 1 is rotated around the central axis X1 (θ1) and the gear cutting tool 2 is rotated around the central axis X2 (θ22) (step S2 in FIG. 3A, rotation control step). Then, first, the top surface 2aa of the blade 2a of the gear cutting tool 2 is processed.

  That is, the control device 20 moves the grinding wheel 1 in the radial direction of the gear cutting tool 2 in order to form the front clearance angle α when moving the grinding wheel 1 in the direction of the central axis X2 of the gear cutting tool 2. Change gradually and move. Then, as shown in FIG. 8, in the groove surface 1ad between the adjacent grinding portions 1a of the grinding wheel 1, pre-finishing grinding and finish grinding are continuously performed on the top surface 2aa of the blade 2a of the gear cutting tool 2 ( Step S3 of FIG. 3A, movement control step). The amount of movement when gradually changing the grinding wheel 1 in the radial direction of the gear cutting tool 2 is set based on the front clearance angle α formed on the top surface 2aa of the blade 2a of the gear cutting tool 2.

  Then, the control device 20 determines whether or not the grinding of the top surfaces 2aa of all the blades 2a of the gear cutting tool 2 is completed (step S4 in FIG. 3A), and the tops of all the blades 2a of the gear cutting tool 2 are determined. When the grinding of the surface 2aa has not been completed, the process returns to step S3 and the above-described processing is repeated. On the other hand, in step S4, when the grinding of the top surfaces 2aa of all the blades 2a of the gear cutting tool 2 is completed, next, the right side surface 2ab of the blade 2a of the gear cutting tool 2 is processed.

  That is, when the grinding wheel 1 is moved in the direction of the central axis X2 of the gear cutting tool 2, the control device 20 intersects the right side surface 2ab of the blade 2a of the gear cutting tool 2 to form a side clearance angle γ. Change the angle η and move it. Then, as shown in FIG. 8, on the left side surface 1ab of the grinding portion 1a of the grinding wheel 1, pre-finishing grinding and finish grinding are continuously performed on the right side surface 2ab of the blade 2a of the gear cutting tool 2 (see FIG. 3A). Step S5, movement control step). The angle of the intersecting angle η to be changed is set based on the side clearance angle γ formed on the right side surface 2ab of the blade 2a of the gear cutting tool 2.

  Then, the control device 20 determines whether or not the grinding of the right side surface 2ab of all the blades 2a of the gear cutting tool 2 is completed (step S6 in FIG. 3A), and the right side of all the blades 2a of the gear cutting tool 2 is determined. When the grinding of the surface 2ab has not been completed, the process returns to step S5 and the above-described processing is repeated. On the other hand, in step S6, when the grinding of the right side surface 2ab of all the blades 2a of the gear cutting tool 2 is completed, the groove surface of the blade 2a of the gear cutting tool 2 is processed next.

  That is, when the grinding wheel 1 is moved in the direction of the central axis X2 of the gear cutting tool 2, the control device 20 restores the angle of the intersection angle η and moves the grinding wheel 1. Then, as shown in FIG. 8, pre-finishing grinding and finish grinding are continuously performed on the groove surface 2ad of the blade 2a of the gear cutting tool 2 at the top surface 1aa of the grinding portion 1a of the grinding wheel 1 (see FIG. 3B). Step S7, movement control step).

  Then, the control device 20 determines whether or not the grinding of the groove surfaces of all the blades 2a of the gear cutting tool 2 is completed (step S8 in FIG. 3B), and the groove surfaces of all the blades 2a of the gear cutting tool 2 are determined. If the grinding is not completed, the process returns to step S7 and the above-described processing is repeated. On the other hand, when the grinding of the groove surfaces of all the blades 2a of the gear cutting tool 2 is completed in step S8, next, the left side surface 2ac of the blade 2a of the gear cutting tool 2 is processed.

  That is, when the grinding wheel 1 is moved in the central axis X2 direction of the gear cutting tool 2, the control device 20 forms a side clearance angle γ with the left side surface 2ac of the blade 2a of the gear cutting tool 2 in order to form a side clearance angle γ. Change the angle η and move it. Then, as shown in FIG. 8, pre-finishing grinding and finish grinding are continuously performed on the right side surface 1ac of the grinding portion 1a of the grinding wheel 1 on the left side surface 2ac of the blade 2a of the gear cutting tool 2 (see FIG. 3B). Step S9, movement control step). The angle of the intersecting angle η to be changed is set based on the side clearance angle β formed on the left side surface 2ac of the blade 2a of the gear cutting tool 2.

  Then, the control device 20 determines whether or not the grinding of the left side surfaces 2ac of all the blades 2a of the gear cutting tool 2 is completed (step S10 in FIG. 3B), and the left side of all the blades 2a of the gear cutting tool 2 is determined. When the grinding of the surface 2ac is not completed, the process returns to step S9 and the above-described processing is repeated. On the other hand, in step S10, when the grinding of the left side surface 2ac of all the blades 2a of the gear cutting tool 2 is completed, the grinding wheel 1 is moved to the retracted position and stopped (step S11 in FIG. 3B), and the grinding wheel 1 is moved. And the rotation of the gear cutting tool 2 is stopped (step S12 of FIG. 3B), and all the processes are ended.

  In the operation of the control device 20 described above, the right side surface 2ab and the left side surface 2ac of the blade 2a of the gear cutting tool 2 are processed by changing the angle of the intersection angle η. However, when the grinding wheel 1 is relatively moved in the direction of the central axis X2 of the gear cutting tool 2, the control device 20 moves the grinding wheel 1 in the translational direction M33 which is the rotational tangential direction of the gear cutting tool 2. Move gradually. Then, in order to form the side clearance angle γ with respect to the right side surface 2ab and the left tooth surface 2ac of the blade 2a of the gear cutting tool 2, respectively, the blade of the gear cutting tool 2 is formed on the right side surface 1ac of the grinding portion 1a of the grinding wheel 1. The pre-finishing grinding and the finishing grinding may be continuously performed on the left side surface 2ac of 2a.

(4. Other)
In the above-described embodiment, between the left side surface 1ab and the right side surface 1ac of the grinding portion 1a of the grinding wheel 1, the center is formed in a barrel shape swelling on both sides in the circumferential direction of the grinding wheel 1. Accordingly, the grinding wheel 1 can reciprocate in the direction of the central axis X2 of the gear cutting tool 2 to process the gear cutting tool 2. However, as shown in FIG. 9 corresponding to FIG. 4C (the same constituent parts are given the same numbers), the grinding wheel 1 on the other end surface 1B side is between the left side surface 1ab and the right side surface 1ac of the grinding part 1a of the grinding wheel 1. It may be formed in the most bulged shape on both sides in the circumferential direction. In this case, the grinding wheel 1 moves in only one direction in the central axis X2 direction of the gear cutting tool 2 to process the gear cutting tool 2.

  A side clearance angle γ is provided on the right side surface 2ab and the left side surface 2ac of the blade 2a of the gear cutting tool 2. As a result, the grinding wheel 1 processes the right side surface 2ab and the left side surface 2ac of the blade 2a of the gear cutting tool 2 one by one. However, the side clearance angle γ may not be provided on the right side surface 2ab and the left side surface 2ac of the blade 2a of the gear cutting tool 2 (the side clearance angle γ is 0 degree). In this case, the grinding wheel 1 The right side surface 2ab and the left side surface 2ac of the blade 2a of the tool 2 can be machined simultaneously.

  Further, the spindle unit 11 is configured to be movable with respect to the rotary table 12. However, the main spindle unit 11 and the rotary table 12 may be relatively moved, and the rotary table 12 may be movable with respect to the main spindle unit 11.

  1: Grinding wheel, 1a: Grinding part, 1aa: Top surface, 1ab: Left side surface, 1ac: Right side surface, 1ad: Groove surface, 2: Gear cutting tool, 2a: Blade, 3: Gear, 3a: Teeth, 10: Processing device for gear cutting tool, 20: control device, 21: rotation control unit, 22: movement control unit, Sa, Sb: cross-sectional shape

Claims (8)

The gear cutting tool is formed in the shape of an external gear and has a grinding wheel with external teeth as a grinding portion, and a gear cutting tool used for skiving having a plurality of blades on the peripheral surface is a grinding target, and the gear cutting tool is used by the grinding wheel. A machining device for a gear cutting tool that grinds
The grinding wheel, the circumferential sectional shape of the grinding wheel in the grinding portion is formed for at least pre-finishing grinding and finish grinding,
With the central axis of the grinding wheel and the central axis of the gear cutting tool being orthogonal to each other, the grinding wheel is rotated around the central axis of the grinding wheel while being inclined by a crossing angle, and the gear cutting tool is A rotation controller for rotating the gear around the central axis of the gear cutting tool,
A movement control unit that relatively moves the grinding wheel in the central axis direction of the gear cutting tool, and continuously performs pre-finishing grinding and finish grinding of the blade in the grinding unit,
A machining device for a gear cutting tool.   When the grinding portion is viewed in the radial direction from the central axis, the left and right side surfaces of the grinding portion are formed in a barrel shape that swells to both sides in the circumferential direction of the grinding wheel, and between the left and right side surfaces of the grinding portion. The cross-sectional shape of the minimum wall thickness portion in the circumferential direction of the grinding wheel is formed for the pre-finishing grinding, and the cross-sectional shape of the maximum wall thickness portion in the circumferential direction of the grinding wheel between the left and right side surfaces of the grinding portion is the finish. The processing device for a gear cutting tool according to claim 1, which is formed for grinding.   On the left and right side surfaces extending in the central axis direction of the grinding wheel in the grinding portion, there is a side clearance angle formed by a straight line extending a side surface profile in the central axis direction of the grinding wheel and a straight line parallel to the central axis of the grinding wheel. The machining device for a gear cutting tool according to claim 1, which is provided respectively.   The top surface of the grinding portion has a front clearance angle formed by a tangent line at an end point on the end surface side of the grinding wheel and a straight line parallel to the center axis of the grinding wheel in the top surface contour in the central axis direction of the grinding wheel. The machining device for a gear cutting tool according to claim 1, wherein the machining device is provided. The gear cutting tool is formed in the shape of an external gear and has a grinding wheel with external teeth as a grinding portion, and a gear cutting tool used for skiving having a plurality of blades on the peripheral surface is a grinding target, and the gear cutting tool is used by the grinding wheel. A method of processing a gear cutting tool for grinding
The grinding wheel, the circumferential sectional shape of the grinding wheel in the grinding portion is formed for at least pre-finishing grinding and finish grinding,
With the central axis of the grinding wheel and the central axis of the gear cutting tool being orthogonal to each other, the grinding wheel is rotated around the central axis of the grinding wheel while being inclined by a crossing angle, and the gear cutting tool is A rotation control step of rotating the gear about the central axis of the gear cutting tool,
A movement control step of relatively moving the grinding wheel in the central axis direction of the gear cutting tool, and continuously performing pre-finishing grinding and finish grinding of the blade in the grinding section;
And a method for processing a gear cutting tool.   In the movement control step, when relatively moving the grinding wheel in the central axis direction of the gear cutting tool, the crossing angle is changed to move the central axis direction of the gear cutting tool in the gear cutting tool. The method for machining a gear cutting tool according to claim 5, wherein side clearance angles formed by the right and left side surfaces and a straight line parallel to the central axis of the gear cutting tool are provided on the left and right side surfaces extending in the direction.   The movement control step gradually changes the amount of movement of the grinding wheel in a translational direction which is a rotational tangential direction of the gear cutting tool when the grinding wheel is relatively moved in the central axis direction of the gear cutting tool. The side clearance angles formed by the left and right side surfaces and a straight line parallel to the central axis of the gear cutting tool are provided on the left and right side surfaces of the gear cutting tool that extend in the central axis direction of the gear cutting tool, respectively. 5. The method for processing a gear cutting tool according to item 5.   In the movement control step, when relatively moving the grinding wheel in the central axis direction of the gear cutting tool, the grinding wheel is gradually moved in the radial direction of the gear cutting tool to move, The gear cutting tool according to any one of claims 5 to 7, wherein a front clearance angle formed by the top surface and a straight line parallel to the central axis of the gear cutting tool is provided on the top surface of the blade of the gear cutting tool. Processing method.

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