JP2001157918A - Tooth profile cutting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tooth profile cutting method which can summarize the process by adding the tooth profile cutting function by a pinion cutter to the function of an numerically controlled lathe and a machining center, and cut a tooth profile of an inclined tooth trace with respect to the axis line the taper involute spline while suppressing the cost increase. SOLUTION: The tooth profile is cut by relatively moving the pinion cutter 11 along the inclined tooth trace while synchronously rotating the pinion cutter 11 and a work W. When the pinion cutter 11 is relatively moved along the tooth trace, the rotational speed ratio of the pinion cutter 11 or the work W is changed so that the peripheral speed of a contact portion of the pinion cutter 11 is agreed with that of the work W.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tooth profile cutting method for forming a tooth profile, such as a tapered involute spline, whose teeth are inclined with respect to an axis by an NC lathe and a machining center.

[0002]

2. Description of the Related Art
The tapered involute spline is cut by a broach cutter using a dedicated broaching machine with the broach shaft and the workpiece mounting shaft being inclined.

[0003] Since the cutting of the tapered involute spline is limited to a broaching machine, when a hole is formed on the work and a tooth profile is formed, a machining center is required to complete the work. And a broaching machine are required. As described above, in the combined machining, a large amount of cost is required for a plurality of devices, their installation space, transportation between the devices, setup change of each device, and the like. It has become.

The broach cutter used for this broaching machine is very expensive because it is manufactured individually for each workpiece.

[0005] When machining a tooth profile having tooth traces inclined with respect to the axis, such as a bevel gear, a tapered involute spline, etc., a cutter shaft for mounting a gear cutting cutter and a table shaft for mounting a workpiece. There is known a machining method in which a cutter is reciprocated and a table is rotated by generating movement of a table, and a method in which a broach shaft and a table shaft are inclined to perform broaching.

[0006] However, in the above-mentioned processing method, the main shaft or the broach shaft is inclined to the table shaft.
There is a problem that it is a versatile processing machine with poor versatility, and even if the table inclination angle is changeable, it becomes expensive due to the complicated structure. Further, there is a disadvantage that a very expensive broach cutter must be used as described above.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional drawbacks, and an object of the present invention is to add a tooth profile machining function using a pinion cutter to the functions of an NC lathe or a machining center to consolidate processes. It is another object of the present invention to provide a tooth profile cutting method capable of reducing the tool cost by changing the broach cutter to a pinion cutter.

[0008]

Accordingly, a tooth profile cutting method according to a first aspect of the present invention is a tooth profile cutting method for forming a tooth profile in which a tooth trace is inclined with respect to an axis Ow, such as a tapered involute spline and a taper serration. In the rotary tool mounting shaft 12 capable of controlling the rotation angle of the NC lathe,
, A workpiece W is mounted on a workpiece mounting shaft 2 whose rotation angle can be controlled, and the pinion cutter 11 and the workpiece W are synchronously rotated while simultaneously rotating the pinion cutter 11 with the axis Ow. A tooth profile cutting method for performing a cutting process by relatively moving along a tooth trace inclined with respect to the pinion cutter, when the pinion cutter 11 is relatively moved along a tooth trace, It is characterized in that the rotational speed ratio between the rotary tool mounting shaft 12 and the workpiece mounting shaft 2 is changed so that the peripheral speed in the rotational direction of the contact portion between the workpiece 11 and the workpiece W is matched.

According to the tooth profile cutting method of the first aspect, the rotary tool mounting shaft 12 capable of controlling the rotation angle of the NC lathe.
The pinion cutter 11 is attached to the workpiece, and the workpiece W, which is also attached to the workpiece mounting shaft 2 whose rotation angle can be controlled, is synchronously rotated at a certain common ratio, and at the same time, the pinion cutter 11 is relatively moved along the tooth trace. , It is possible to perform tooth profile cutting such as taper involute spline and taper serration. In particular, when the pinion cutter 11 is relatively moved along the tooth trace inclined with respect to the axis Ow, the rotation speed ratio between the rotary tool mounting shaft 12 and the workpiece mounting shaft 2 is changed, and the pinion cutter 11 is rotated. Since the peripheral speed in the rotational direction of the contact portion between the cutter 11 and the workpiece W is made to be the same, the tooth profile cutting having the tooth traces inclined with respect to the axis Ow can be accurately performed.

[0010] Therefore, the workpiece W, which requires both the turning process and the tooth profile process, can be finished to a finished product by one NC lathe, and can cope with a large variety of small quantities.
Further, the steps can be integrated. Furthermore, since a pinion cutter can be used, tool cost can be reduced. As described above, according to the tooth profile cutting method of the first aspect, it is possible to consolidate the steps, and in addition, it is possible to reduce the tool cost.

According to a second aspect of the present invention, there is provided a tooth profile cutting method for forming a tooth profile in which teeth are inclined with respect to an axis Ow, such as a tapered involute spline and a tapered serration. The pinion cutter 11 is mounted on the main shaft 40 whose angle is controllable, and the workpiece W is mounted on a mounting table 33 movable in a plane direction perpendicular to the rotation axis Op of the pinion cutter 11, and the pinion cutter 11 of the workpiece W is attached. The cutting process is performed by synchronously rotating the circular interpolation motion with respect to the rotation speed of the pinion cutter 11 at a certain common ratio and simultaneously moving the pinion cutter 11 relatively along the tooth trace inclined with respect to the axis Ow. The pinion cutter 11 is relatively moved along a tooth streak when the pinion cutter 11 is moved. Jitter 11 to match the peripheral speed of the rotating direction of the contact portion between the workpiece W, and is characterized in that changing the rotational speed ratio between the table 33 mounting the spindle 40.

According to the tooth profile cutting method of the second aspect, the pinion cutter 11 is mounted on the main shaft 40 of the machining center whose rotation angle can be controlled.
By rotating the pinion cutter 11 relatively along the tooth trace while simultaneously rotating the circular interpolation motion relative to the workpiece W and the rotation speed of the pinion cutter 11 at a fixed common ratio, the taper Tooth cutting such as involute spline and taper serration can be performed. In particular, when the pinion cutter 11 is relatively moved along the tooth trace inclined with respect to the axis Ow, the rotation speed ratio between the main shaft 40 or the mounting table 33 is changed to change the pinion cutter 11 and the workpiece. Since the peripheral speed in the rotation direction of the contact portion with W is made to be the same, it is possible to perform a tooth profile cutting process having a tooth trace inclined with respect to the axis Ow.

Therefore, the workpiece W, which requires both drilling and tooth forming, can be finished into a finished product with a single machining center, and can be used even in a small variety of products and the number of machining days can be reduced. . Furthermore, since a pinion cutter can be used, tool cost can be reduced. As described above, according to the tooth profile cutting method of the second aspect, it is possible to consolidate the steps and to reduce the tool cost.

The tooth cutting method according to a third aspect is characterized in that the rotary tool mounting shaft 12 according to the first aspect or the main shaft 40 according to the second aspect is reciprocally driven in the axial direction. By doing so, the control configuration can be simplified.

According to a fourth aspect of the present invention, the pinion cutter 11 is provided with a pressure angle α of tan α = c.
osΦ · tanθ (Φ is the inclination angle between the relative movement direction of the pinion cutter 11 and the axis Ow, and θ is the pressure angle of the tooth profile to be formed on the workpiece W). While rotating the rotation axis 11 so that the rotation axis Op is parallel to the axis Ow of the workpiece W, the pinion cutter 11 is simultaneously moved relatively along the tooth trace inclined with respect to the axis Ow. It is characterized by performing tooth profile cutting.

According to the tooth profile cutting method of the fourth aspect, by providing the pressure angle α of the pinion cutter 11 as described above, it is possible to form a tooth profile having a desired pressure angle θ on the workpiece W. . By mounting the pinion cutter 11 having the predetermined pressure angle α in this way, the inclination angle Φ
By moving the pinion cutter 11 relative to the workpiece W in accordance with the above, it is possible to perform shaping of a tooth profile having tooth traces inclined at a desired angle φ with respect to the axis Ow. Therefore, by changing the relative movement direction of the pinion cutter 11, the inclination angle Φ of the tooth profile can be changed, and by replacing the pinion cutter 11 with a different pressure angle α, the tooth shape with a desired pressure angle θ can be formed. Processing can be performed. Therefore, unlike the conventional machining method, there is no need to incline the main shaft or the like with respect to the table axis, the structure is simple, and the tooth profile cutting can be performed by a versatile apparatus.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an example of an NC machine tool used in an embodiment of a tooth cutting method using an NC lathe. In this NC machine tool, a workpiece mounting shaft 2 is mounted on a workpiece mounting shaft base 1 so as to be able to control the rotation angle, and a chuck 3 is fitted to a tip of the workpiece mounting shaft 2. I have. The workpiece W is fixed to the chuck 3.

On the other hand, a tool rest turret 5 is provided on a tool rest 4 which can be moved and positioned in the Z-axis direction and the X-axis direction so as to be able to rotate around a turning center axis in the Z-axis direction. The pinion cutter 11 is attached to the rotary tool attachment shaft 12 of No. 5. The rotary tool mounting shaft 12 is a drive shaft of the rotary tool, and has a clutch 2 at the right end.
6A is fitted, and the clutch 26A is attached to the tool post 4
26B fitted to the tip of a Z-axis rotating shaft 27 rotatably provided at the turret indexing position
And is detachably engaged. The rotating shaft 27 is driven by a servomotor 29 fixed to the tool rest 4 via a synchro belt 28. The servomotor 29 and a workpiece mounting shaft motor (not shown) for driving the workpiece mounting shaft 2 are controlled by an NC device so as to rotate synchronously at a constant common ratio.

Next, the pinion cutter 11 provided on the NC lathe
A method of tooth profile cutting by the method will be described. Here, using a pinion cutter 11 having a reference pitch circle diameter D and a tooth pressure angle α, the tooth streak is inclined at an angle Φ with respect to the axis Ow.
A method of machining a tapered internal spline inclined at a pressure angle θ will be described with reference to FIGS. FIG.
FIG. 4 is an explanatory diagram for explaining movement of the pinion cutter 11 in the Z-axis direction with respect to the workpiece W in the processing method of the present embodiment. FIG. 3A is an enlarged view of a main part of FIG.
(B) is a view of the contact state between the pinion cutter and the workpiece at the cutting start end as viewed from the axial direction, and (c) is a diagram illustrating the inclination of the tooth profile of the workpiece formed by the pinion cutter at the cutting end. It is the end view seen. FIG. 4 is an explanatory diagram viewed from the Z-axis direction for explaining a relative rotation between the workpiece W and the pinion cutter in the processing method of the embodiment.

In this embodiment, the workpiece W is rotated, and the pinion cutter 11 is moved in the Z-axis direction while rotating, thereby performing tooth profile cutting. As shown in FIG. 2, the movement of the pinion cutter 11 from the feed start point to the cutting start end, the cutting end, and the feed end point is slightly retracted to the axis Ow side of the workpiece W at the feed end point, as shown in FIG. Then, the cycle of retreating to the side of the feed start point and moving to the feed start point again is repeated. In addition,
The movement from the cutting end to the cutting start end in the above cycle is sufficient if the pinion cutter 11 is provided so as not to interfere with other members.

A pinion cutter 11 for performing this shaping
As shown in FIG. 3A, the rotation axis O of the pinion cutter 11 from the axis Ow of the workpiece W to correspond to the inclination angle Φ of the tooth trace of the tapered internal tooth spline (the workpiece W).
The distance p is moved so that X1 is at the cutting start end and X2 is at the cutting end. The position X1 on the X axis of the rotation axis Op of the pinion cutter 11 at the cutting start end starts from a position that satisfies the expression X1 = (m · Zw−m · Zp) / 2. In this equation, m is the module of the pinion cutter 11 and Zp is the pinion cutter 11
, Zw means the number of teeth of the tooth profile to be formed. Further, the pinion cutter 11 moves in a direction inclined at an inclination angle Φ with respect to the axis Ow (center axis) of the workpiece W from the cutting start end to the cutting end. In the present embodiment, X1 is set to be larger than X2, and the pinion cutter 11 moves from the cutting start end to the cutting end so as to approach the axis Ow of the workpiece W. However, on the contrary, it is also possible to set X2 to be larger than X1, and to set so that the pinion cutter 11 moves away from the axis Ow of the workpiece W from the cutting start end to the cutting end. However, in this case, since the clearance angle of the pinion cutter 11 needs to be larger than the cutting angle (the inclination angle Φ of the tooth trace with respect to the axis Ow), X1 is set to be larger than X2 as in the above embodiment. Is preferred.

From the cutting start end to the cutting end, the workpiece W and the pinion cutter 11 are controlled so that the peripheral speed in the rotational direction of the contact portion is the same. That is,
The rotational speed ratio between the two is ωpt / ωwt = [(2Xt +
D) · ωp1] / [(2X1 + D) · ωw1]. In this equation, ωw means the rotation speed of the workpiece W, ωw1 is the rotation speed at the cutting start end, and ωwt is the distance between the rotation axis Op and the axis Ow of the workpiece W up to the cutting end. Means the rotation speed at the position Xt. Ωp means the rotation speed of the workpiece W, ωp1 is the rotation speed at the cutting start end, and ωpt is the rotation axis Op up to the cutting end.
The distance between the workpiece and the axis Ow of the workpiece W means the rotation speed at the position Xt. D is the diameter of the reference pitch circle of the pinion cutter 11. Here, the pinion cutter 11
Is changed, and the rotation speed of the workpiece W is not changed (when ωwt = ωw1), ωpt / ω
The rotation speed of the pinion cutter 11 is controlled so that p1 = (2Xt + D) / (2X1 + D). By controlling the rotation speed of the pinion cutter 11 (rotary tool mounting shaft 12) in this manner, it is possible to perform the tooth profile cutting of the tapered internal tooth spline whose tooth trace is inclined with respect to the axis Ow. When the cutting speed of the pinion cutter 11 in the Z-axis direction is set to a constant speed, ωp2 / ω
The rotation speed ωp2 at the cutting end such that p1 = (2X2 + D) / (2X1 + D) is obtained, and the rotation speed of the pinion cutter 11 from the cutting start end to the cutting end is ωp1.
To ωp2. Similarly, when the rotation speed of the pinion cutter 11 is not changed (ωpt = ωp1
), Ωwt / ωw1 = (2X1 + D) / (2
By controlling the rotation speed of the workpiece W so as to satisfy (Xt + D), it is possible to perform the tooth profile cutting of the tapered internal spline in which the teeth are inclined with respect to the axis Ow.

The pinion cutter 11 has a pressure angle α satisfying tan α = cos Φ · tan θ. Here, Φ is the inclination angle Φ (the inclination angle of the tooth trace with respect to the axis Ow) between the moving direction of the pinion cutter 11 along the Z axis and the axis Ow, and θ is the tooth shape to be formed on the workpiece W. Means pressure angle.

FIG. 5 shows a case where the machining of the tapered external spline is performed. As in the case of the machining of the tapered internal spline, the pinion cutter 11 is set at the cutting start end by X1 = (m · Zw + m · Zp) / Starting from the position 2, the rotational speed is set to ωpt / ωwt = [(2Xt−
D) · ωp1] / [(2X1-D) · ωw1]. When the rotation speed of the workpiece W is not changed (when ωwt = ωw1), ωpt /
The rotation speed of the pinion cutter 11 is controlled so that ωp1 = (2Xt−D) / (2X1−D).

Next, as a second embodiment of the present invention,
An embodiment in which a tooth shape is cut by a machining center will be described. FIG. 6 shows an example of a machining center used in the embodiment of the tooth profile cutting method using the machining center. This machining center has a base 31
And a Y table 32 provided on the base 31 so as to be movable in the Y-axis direction, and an X table 33 provided on the Y table 32 so as to be movable in the X-axis direction.
The workpiece W is fixed on the table 33.

The Y table 32 is driven in the Y axis direction by a Y axis motor 34, and the X table 33 is driven in the X axis direction by an X axis motor 35. The workpiece W on the X table 33 is axially controlled to an arbitrary coordinate position by the X coordinate and the Y coordinate along the horizontal plane by the movement of the X table 33 and the Y table 32 in the XY plane. It has become.

On the other hand, a Z-axis slider 37 is mounted on the column 36 of the machining center so as to be movable in the vertical direction, that is, in the Z-axis direction. The Z-axis slider 37 is driven in the Z-axis direction by a Z-axis motor 38. . A spindle head 39 is attached to the Z-axis slider 37.
In the spindle head 39, the spindle 40 has an axis O in the same direction as the Z axis.
It is mounted so as to rotate around w, that is, around the C axis. The spindle 40 is driven to rotate by a spindle motor 41, and the pinion cutter 11 is mounted on the spindle 40.

The X-axis motor 35, Y-axis motor 34, Z
The shaft motor 38 and the main shaft motor 41 are both servo motors, and these motors 35, 34, 38, 41 have rotary encoders 43, 44, 4, respectively.
5 and 46 are attached, and the encoders 43 and 4
4, 45 and 46 detect the rotation angles of the respective shaft motors 35, 34 and 38 and the main shaft motor 41, and output information on the rotation angles to the control device 50.

As shown in FIG. 7, the control device 50
It has a main control unit 51 that executes a C machining program and outputs each axis command and a main shaft rotation command, and a calculation unit 52 that inputs an axis command from the main control unit 51 and performs an interpolation operation. The calculation unit outputs the movement amounts of the X, Y, and Z axes as command values to the position control units 53, 54, 55, and 56 of the respective axes. These position control units 53, 54,
55 and 56 receive rotation information from rotary encoders 43, 44, 45 and 46 provided coaxially, and control the motors 35, 34, 38, 41
This is for controlling the driving of.

Next, a description will be given of a method of forming a tooth profile using the machining center. Here, a method of machining a tapered internal tooth spline having a reference pitch circle diameter D and a tooth pressure angle α using a pinion cutter 11 with a tooth center inclined at an inclination angle Φ with respect to an axis Ow and a pressure angle θ will be described. I do. Note that a description of the same points as those of the tooth forming method using the NC lathe of the first embodiment is partially omitted.

In this embodiment, the pinion cutter 11
Is rotated to the Z-axis side, and the workpiece W is moved around the pinion cutter 11 by circular interpolation motion to perform tooth profile cutting.

The movement of the workpiece W is performed in order to move the pinion cutter 11 relatively in accordance with the revolution on the circumference centered on the rotation axis Op of the pinion cutter 11 and the inclination angle Φ of the tooth trace. Is moved by an amount obtained by integrating the moving amount of the moving object. That is, in the workpiece W, the contact portion with the pinion cutter 11 is located on the circumference of the radius R1 at the cutting start end, and on the circumference of the radius R2 closer to the axis Ow than the radius R1 at the cutting end. Move to position. Where R1
= (M · Zw−m · Zp) / 2, and R2 = R1−d
TanΦ. In this equation, m1 is a module of the pinion cutter 11, Zp is the number of teeth of the pinion cutter 11, and Zw is the number of teeth of a tooth shape to be formed. Also,
d is the width of the workpiece W (tooth width of the tooth profile), Φ is the inclination angle of the tooth trace, and is the relative movement direction of the pinion cutter 11 with respect to the axis Ow of the workpiece W. . When the pinion cutter 11 reaches the feed end point, the pinion cutter 11 moves the axis Ow of the workpiece W in the same manner as in the first embodiment.
The workpiece W moves so as to slightly retreat to the side, rises to the side of the feed start point, and moves to the feed start point again.

The movement of the workpiece W is performed by the axis control (circular interpolation) of the X table 33 and the Y table 32. In addition, the period Nw of revolution of the workpiece W,
The rotation speed Np of the rotation of the pinion cutter 11 is Nw / N
It is controlled so as to satisfy the relationship of p = Zw / Zp.

The revolution of the workpiece W (movement after subtracting the movement for relative movement of the pinion cutter 11 in the tilt direction) and the rotation of the pinion cutter 11 are from the cutting start end to the cutting end. Control is performed so that the peripheral speeds in the rotational direction of the respective contact portions are made to match. That is,
As in the first embodiment, the rotational speed ratio between the two is ωpt /
ωwt = [(2Rt + D) · ωp1] / [(2Rt +
D) · ωw1]. In this formula, ωw means the rotation speed of the revolution of the workpiece W, ωw1 is the rotation speed at the cutting start end, and ωwt
Is the rotation axis Op and the workpiece W up to the cutting end.
Means the rotation speed at the position of Xt. Further, ωp means the rotation speed of the pinion cutter 11 rotating, and ωp1 is the rotation speed at the cutting start end.
pt means the rotation speed at a position where the distance between the rotation axis Op and the axis Ow of the workpiece W up to the cutting end is Xt. D is the diameter of the reference pitch circle of the pinion cutter 11. Here, when only the rotation speed of the rotation of the pinion cutter 11 is changed and the rotation speed of the revolution of the workpiece W is not changed (when ωwt = ωw1), ωpt
The rotation speed of the pinion cutter 11 is controlled so that / ωp1 = (2Rt + D) / (2R1 + D). Thus, the pinion cutter 11 (the rotary tool mounting shaft 1)
By controlling the rotation speed of 2), it is possible to form the tapered internal tooth spline whose tooth trace is inclined with respect to the axis Ow. When the cutting speed of the pinion cutter 11 in the Z-axis direction is set to a constant speed, ωp2 / ωp
The rotation speed ωp2 at the cutting end may be determined so that 1 = (2X2 + D) / (2X1 + D), and the rotation speed of the pinion cutter 11 may be sequentially changed from ωp1 to ωp2 from the cutting start end to the cutting end.

FIG. 8 shows a case in which a tapered external spline is machined. In the same manner as in the case of the tapered internal spline described above, the pinion cutter 11 is set to R1 = (mZw + mZp) at the cutting start end. ) / 2, the rotational speed ratio is defined as ωpt / ωwt = [(2R
Control is performed so as to satisfy the expression of (t−D) · ωp1] / [(2R1-D) · ωw1]. When the rotation speed of the revolution of the workpiece W is not changed, ωpt / ωp1 = (2R
The rotation speed of the pinion cutter 11 is controlled so that (t−D) / (2R1−D). If the revolution radius is set to infinity, rack machining can be performed.

In the above description, a method in which the machining method using an NC lathe is applied to a machining center has been described. However, in the case where a machining center is used, the workpiece W between the cutting start end and the cutting end is used. By adopting a machining method that makes the peripheral speeds in the rotational direction of the respective contact portions between the pinion cutter 11 and the pinion cutter 11 coincide with “zero”,
The control can be performed easily and easily.

As described above, according to the tooth profile cutting method according to the first and second embodiments, when the tooth profile cutting is performed by relatively moving the pinion cutter 11 along the tooth trace, the pinion cutter 11 Alternatively, it is possible to change the rotation speed of one or both of the workpieces W, that is, change the rotation speed ratio of both, so that the peripheral speed in the rotation direction of the contact portion between the pinion cutter 11 and the workpiece W can be matched. Therefore, it is possible to perform a tooth profile cutting process such as a tapered involute spline having a tooth with a tooth sloping with respect to the axis Ow.

In particular, since the pressure angle α of the pinion cutter 11 is set as described above from the pressure angle θ and the inclination angle Φ of the tooth profile to be formed, a tooth profile having a desired pressure angle θ is formed on the workpiece W. I can do it. Thus, the desired pressure angle α
By mounting the pinion cutter 11 having the above, and moving the pinion cutter 11 relatively to the workpiece W in accordance with the inclination angle Φ of the tooth trace to be formed, the desired angle Φ is inclined with respect to the axis Ow. It is possible to perform a tooth profile cutting process with toothed teeth. Therefore, by changing the relative movement direction of the pinion cutter 11, the inclination angle Φ of the tooth trace can be changed, and by replacing the pinion cutter 11, shaping of a tooth shape having a desired pressure angle θ can be performed. Becomes possible. Therefore, unlike the conventional machining method, there is no need to incline the main shaft or the like with respect to the table axis, the structure is simple, and the tooth profile cutting can be performed by a versatile apparatus.

FIG. 9 is a conceptual diagram showing the difference between the tooth profile cutting according to the present invention and a method of driving a pinion cutter by a conventional crank mechanism. The cutting feed of the pinion cutter, including the normal NC drive, is performed by a crank device. In the machining stroke, measures are taken to avoid large fluctuations in the cutting speed. However, since a crank mechanism is employed, the cutting is performed from the cutting start end to the cutting end as shown by a solid sine waveform in FIG. Large fluctuations in speed cannot be avoided. As shown by the solid line in FIG. 9, the maximum cutting speed is obtained in the middle of the tooth width, and the cutting speed becomes extremely small at the cutting start end and the cutting end. In such machining, the cutting tool needs to select its wear resistance and rigidity according to the point where the cutting speed is highest. Therefore, from the viewpoint of the cutting tool, the tooth profile machining by the conventional pinion cutter is not performed at a speed corresponding to the tool performance, and the work efficiency is poor, and conversely, the average cutting In terms of speed, you are using over-performance cutting tools.

On the other hand, according to the tooth profile cutting method using the NC lathe and the machining center according to the first and second embodiments, as shown by a trapezoidal wave indicated by a broken line in FIG. It has a function to give a cutting speed of. Therefore, a cutting tool according to the cutting speed can be selected. Therefore, from the viewpoint of the pinion cutter 11, machining can be performed at the maximum cutting speed corresponding to the tool performance, and the work efficiency can be improved. On the contrary, since the pinion cutter 11 having the performance corresponding to the cutting speed can be used, the tool cost can be reduced.

In addition, in the first and second embodiments, in addition to turning or boring, external or internal tooth cutting can be performed. Therefore, turning or drilling and tooth forming can be performed. Workpiece W that needs both processing
Can be finished to a finished product with one NC lathe or one machining center. As a result, it is possible to cope with the case of many kinds and small quantities, and it is possible to consolidate processes and shorten the number of working days from material to finished product. Furthermore, NC
In the lathe and the machining center, since a constant cutting speed can be given from the cutting start end to the cutting end, the cutting speed of the pinion cutter 11 is matched with the tool performance, and the cutting efficiency is improved and the tool cost is reduced. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an example of an NC lathe for performing a tooth profile cutting method according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram in a case where a tapered internal tooth spline is processed by a pinion cutter in the first embodiment of the present invention.

3A is an enlarged view of a main part of FIG. 2, FIG. 3B is a view of a contact state between a pinion cutter and a workpiece at a cutting start end viewed from an axial direction, and FIG. It is the end view which looked at the tooth profile of the work by the pinion cutter at the end from the inclination direction.

FIG. 4 is a plan end view of the first embodiment of the present invention in a case where a workpiece and a pinion cutter are synchronously rotated at a fixed ratio to perform tooth profile cutting.

FIG. 5 shows N used in the first embodiment of the present invention.
It is a plane end view at the time of processing a taper external tooth spline with a C lathe.

FIG. 6 is a schematic configuration diagram illustrating an example of a machining center in which a tooth profile cutting method according to a second embodiment of the present invention is performed.

FIG. 7 is a block diagram showing a control system of a machining center used in a second embodiment of the present invention.

FIG. 8 is a plan end view of a machining center used in a second embodiment of the present invention when machining a tapered external spline.

FIG. 9 is a conceptual diagram showing a difference between a tooth profile cutting process according to the present invention and a process using a normal pinion cutter.

[Explanation of symbols]

 2 Workpiece mounting axis 11 Pinion cutter 12 Rotary tool mounting axis 32 Y table 33 X table 37 Z axis slider 40 Main axis W Workpiece Ow Axis center Op Rotating axis

Claims (4)

[Claims] 1. A tooth profile cutting method for forming a tooth profile in which tooth traces such as a tapered involute spline and a tapered serration are inclined with respect to an axis (Ow),
A pinion cutter (11) is mounted on a rotary tool mounting shaft (12) capable of controlling the rotation angle of a C lathe, and a workpiece (W) is mounted on a workpiece mounting shaft (2) whose rotation angle is controllable.
While rotating the pinion cutter (11) and the workpiece (W) synchronously, simultaneously rotate the pinion cutter (11) with the axis (O).
w) is a tooth profile cutting method in which cutting is performed by relatively moving along a tooth trace inclined with respect to w), and when the pinion cutter (11) is relatively moved along the tooth trace, The rotational speed ratio between the rotary tool mounting shaft (12) and the workpiece mounting shaft (2) in order to make the peripheral speed in the rotational direction of the contact portion between the pinion cutter (11) and the workpiece (W) match. A tooth profile cutting method characterized by changing the number of teeth. 2. A main shaft (40) capable of controlling the rotation angle of a machining center in a tooth profile cutting method in which a tooth profile such as a taper involute spline and a taper serration forms a tooth profile inclined with respect to an axis (Ow). Attach the pinion cutter (11) to the pinion cutter (1).
The work (W) is attached to the mounting table (33) movable in a plane direction perpendicular to the rotation axis (Op) of 1), and the work (W) is circularly interpolated with respect to the pinion cutter (11). Cutting by synchronously rotating the rotation speed of the pinion cutter (11) at a fixed common ratio and simultaneously moving the pinion cutter (11) relatively along a tooth trace inclined with respect to the axis (Ow). A tooth profile cutting method for performing machining, wherein when the pinion cutter (11) is relatively moved along a tooth trace, the pinion cutter (11)
A tooth profile cutting method characterized in that a rotational speed ratio between a main shaft (40) and a mounting table (33) is changed so that a peripheral speed in a rotational direction of a contact portion between the main shaft (40) and a workpiece (W) matches. 3. The rotary tool mounting shaft according to claim 1, wherein:
Alternatively, the main shaft (40) according to claim 2 is reciprocally driven in the axial direction thereof. 4. The pinion cutter (11) is provided so that its pressure angle α satisfies tanα = cosΦ · tanθ, and the pinion cutter (11) is mounted on its rotation axis (O).
p) is rotated so as to be parallel to the axis (Ow) of the workpiece (W), and at the same time, the pinion cutter (11) is relatively moved along the tooth trace inclined with respect to the axis (Ow). The tooth profile cutting method according to any one of claims 1 to 3, wherein the tooth profile cutting process is performed by moving the tooth profile cutting process.
Φ is the inclination angle between the relative movement direction of the pinion cutter (11) and the axis (Ow), and θ means the pressure angle of the tooth profile to be formed on the workpiece (W)).