JP2894699B2 - Sector gear cutting method - Google Patents

Description

The present invention relates to a sector gear cutting method.

[Prior art] Conventional sector gears use a pinion cutter to medium- and finish-cut a workpiece roughed by a milling machine.
Being manufactured.

If the rotation angle of the work spindle per work is 180 degrees or more in the conventional middle and finish cutting process, one centering tool is provided on the work spindle and one work center is provided. The work spindle was rotated once each time the surface was cut, and the next work was always centered using the same centering tool.

Also, in the conventional medium cutting and finish cutting processes, 1
If the rotation angle of the work spindle per piece of work is 180 degrees or less, two centering tools are arranged on the work spindle in a 180-degree rotational symmetry, and the work spindle is turned every time one work is cut. The workpiece was half-turned, and the next work was centered using a centering tool different from the centering tool immediately before.

[Problems to be Solved by the Invention] In the related art after centering a work by alternately using two centering tools, two works can be cut per rotation of a work spindle. The cutting efficiency can be doubled as compared with the prior art in which the centering of the work is performed by the regular use of the setting tool.

However, even in the prior art described above, when the rotation angle of the work spindle per one work is 180 degrees or more, the work spindle is one per work.
It was necessary to rotate, and the cutting efficiency was poor.

Further, in the prior art, even when the rotation angle of the work spindle per work is smaller than 180 degrees, it was not possible to cut two or more works per work spindle rotation.

Further, it has been found that in each of the above-mentioned prior arts, there is a problem that only a specific portion of the pinion cutter wears intensively.

The present applicant first arranges N (N ≧ 3) centering tools on the circumference of the work spindle in a rotationally symmetrical manner, in order to improve the above-mentioned problem and improve the cutting efficiency. Were considered to execute the centering of each work by using in order. However, as the number of centering tools increases, the rotation angle of the work spindle for cutting one work decreases, and the number of teeth of the sector gear decreases to one or two.
It turns out that only books can be applied. For example, when five centering tools are arranged rotationally symmetrically around the circumference of a work spindle, the rotation angle of the work spindle per work is 72 degrees, and a work that requires more than that is required. Was difficult to apply.

The present invention has been made in view of such problems,
It is an object of the present invention to provide a sector gear cutting method capable of improving cutting efficiency and life of a pinion cutter.

[Means for Solving the Problems] The sector gear cutting method of the present invention is configured such that a workpiece made of a sector gear rough finish member is gripped by a workpiece gripping part disposed at the tip of a work spindle, Three or more centering tools are arranged on the work spindle so as to be rotationally symmetric with respect to each other about the axis of the work spindle, and one centering tool is brought into contact with a tooth portion of the work while After completing the gripping by the work gripper and centering the work, the one centering tool is returned to the original position, and the work spindle is rotated to rotate the work, The pinion cutter disposed in the vicinity is rotated in synchronization with the rotation of the work spindle and reciprocated in the axial direction to rotate the pinion cutter. After stopping the work spindle and the pinion cutter, the work grip is loosened to remove the work, and the work grip is gripped with a new work. The centering tool and one of the remaining centering tools that are different from the centering tool adjacent to the centering tool used in the rotation direction of the work spindle with respect to the centering tool used immediately before are used. With the plurality of rotations of the work spindle, the centering of each work is sequentially performed by sequentially using all the centering tools.

[Operation] In the sector gear cutting method of the present invention, each time the work is cut, the work is skipped over the next (or immediately after) one or more centering tools adjacent in the rotational direction of the work spindle and used next. The centering tool to be used is selected, and all the centering tools are sequentially used by rotating the work spindle a plurality of times.

Accordingly, the cutting efficiency per rotation of the work spindle is improved (that is, the number of work pieces that can be cut is increased), and the tooth contact of the pinion cutter is increased in proportion to the number of centering tools. The use of each incisor in the incision is equalized. For this reason, the wear of the cutter becomes more uniform, and the life of the cutter is increased.

More specifically, in the centering operation of the present invention, three or more centering tools are rotationally symmetrically disposed around the work holding portion, and at least the centering tool used at the time of centering of the work is rotated at least in the rotation direction. The centering is performed using another centering tool except for at least the adjacent centering tool.

With this configuration, after the centering is performed by the centering tool, the work spindle is rotated (rotated), and the rotation angle of the work spindle required until the cutting is completed is set to the tooth angle of the work. Even if the occupation angle is large, it can be effectively reduced, and the cutting efficiency per work spindle can be improved.

Further, since the pinion cutter rotates in synchronization with the work spindle, a large number of cutting teeth provided on the outer periphery of the pinion cutter are sequentially used by increasing the number of centering tools and sequentially selecting them as described above. As a result, it is also possible to improve the problem that only some of the incisors of the pinion cutter are frequently used and cause uneven wear.

Example An example of a sector gear cutting method according to the present invention will be described with reference to the drawings.

First, FIG. 1 which is a schematic plan view and FIG. 2 which is a cross-sectional view of a cut portion of a sector gear tooth cutting machine which implements this sector gear are shown.

This sector gear hobbing machine includes a base 10 having a rotary drive (not shown) and various hydraulic cylinders described below.
0, a work spindle 1 rotatably held by the base 100 and having a collet chuck 10 at the tip thereof, and a shaft center of the collet chuck 10 (closed to the work spindle 1 and rotatably held by the base 100). 2) and five centering tools 3a to 3e rotationally symmetrically arranged on the outer peripheral surface near the tip of the collet chuck 10. It is configured.

The work spindle 1 has a cylindrical shape having a central hole 15 and is connected to the above-described rotary drive together with the pinion cutter 2 so as to rotate synchronously with the pinion cutter 2 at a predetermined rotation speed ratio. Work spindle 1
The collet chuck 10 that constitutes the work gripping part of
As shown in the figure, a rotating body 11 attached to a tip end of the work spindle 1 with a bolt (not shown), a collet 13 inserted into a central through hole 12 of the rotating body 11, a rotating body 11 And a work receiving portion 14 attached to a first end surface 101 of the base member with a plurality of screws 102. Rotating body part
Reference numeral 11 denotes a head 111 having a large diameter, and a cylindrical portion 112 inserted into the central hole 15 of the work spindle 1 from an end of the head 111 on the side of the work spindle 1. The head 111 and the cylindrical portion 112 are as described above. It has a central through hole 12. The center through hole 12 of the rotating body 11 has a tapered surface 120 formed at an end remote from the work spindle 1 so as to be tapered toward the work spindle 1. Collet 13 is divided into three grips 131
And a cylindrical portion 132 following the cylindrical portion 132. An end (not shown) of the cylindrical portion 132 is connected to a piston (not shown) of a hydraulic cylinder for driving the collet. Further, the grip portion 131 of the collet 13 has a tapered outer peripheral surface that slides on the tapered surface 120 of the central through hole 12. The work receiving portion 14 has a flange shape, and has an insertion hole 140 that guides the insertion of the work 99 and a stopper end 141 that engages with the step portion 98 of the work to terminate the insertion of the work 99.

The pinion cutter 2 is composed of a gear-shaped gear cutting portion 21 and a rotation shaft 22 thereof. The rotation shaft 22 rotates in synchronization with the work spindle 1 and the pinion cutter reciprocates in the axial direction in synchronization with the rotation. It is configured to exercise.

As shown in FIG. 1, the five centering tools 3a to 3e are rotationally symmetrically arranged on the outer peripheral surface near the tip of the collet chuck 10. Each of the centering tools 3 a to 3 e has a pair of bearing projections 30, 30, and a bearing part 32 attached to the outer peripheral surface near the distal end of the collet chuck 10 with a pair of bolts 31.
A pair of bearing holes respectively opened in the bearing projections 30, 30, the both ends of which are swingably held, and a swing shaft including a shaft center of the collet chuck 10. An L-shaped rocking plate 35 is pivotally supported by the rocking plate 34. As shown in FIGS. 1 and 2, a pair of centering balls 36, 36 are arranged at the tip of the L-shaped rocking plate 35 so as to be mirror images of the rocking surface. ing. A coil spring (not shown) having one end locked to the bearing portion 32 and the other end locked to the L-shaped rocking plate 35 is wound around the swing shaft 34,
This coil spring urges the L-shaped rocking plate 35 away from the work 99. Further, a bolt 37 (see FIG. 2) for stopping the rocking is screwed to the L-shaped rocking plate 35. When the head of the bolt 37 comes into contact with the outer peripheral surface of the collet chuck 10, the L-shaped rocking plate 35 is rotated. Further swinging of the moving plate 35 is stopped. Note that a swing lever 5 for swinging each centering tool is disposed on the back surface of the centering tool 3a shown in FIGS. 1 to 3. The swing lever 5 is rotatably held about the center axis of the swing shaft 34 of the centering device 3a at the position shown in FIGS. The swinging lever 5 has a biasing end portion extending at right angles to the rotation direction thereof, and the biasing end portion biases the L-shaped swinging plate 35 so that the L-shaped swinging plate 35
Is configured to swing. A coil spring (not shown) is attached to a rotating shaft (not shown) of the swing lever 5, and the tip of the swing lever 5 is held at the position shown in FIG. 2 by the bias of the coil spring.

Hereinafter, the method of centering the sector gear according to the present embodiment will be described by describing the operation of the above device.

The work 99 is a forged shaft from which three teeth 90, 91 and 92 are roughened, and two adjacent teeth 90 and 91 and 91 and 92
Are roughened so as to be displaced by 36 degrees about the axis of the work 99, respectively.

First, the work 99 is inserted into the insertion hole 140 of the work receiving portion 14 and the internal insertion hole 139 of the collet 13 so that the stopper end 141 of the work receiving portion 14 and the step 98 of the work 99 are brought into contact.
Next, it is manually rocked by the rocking lever 5 to form an L-shaped rocking plate.
By swinging 35, a pair of centering balls 36, 36 of the centering device 3a
Sandwich the teeth 91 at the intermediate position. Thereby, the teeth 91 of the work 99 are centered by the centering tool 3a.

Next, when the collet 13 is moved in the X direction (see FIG. 2), the tapered surface 133 of the grip 131 of the collet 13 slides toward the work spindle 1 along the tapered surface 120 of the rotating body 11. As a result, the gripper 131 grips the work 99 slightly in the axial direction.

Next, when the centering tool 3a is released, the centering tool 3a returns to the original position. Thereafter, the pinion cutter 2 and the work spindle 1 are driven to drive the three teeth 90, 91, 92 of the work 99.
Are sequentially cut by the pinion cutter 2 to finish cutting the work 99. The rotation angle occupied by the three teeth 90, 91, and 92 is 36 degrees x 3 = 108 degrees, but in actual cutting, cutting of these three teeth requires a rotation of about 130 degrees. In this embodiment, the work spindle 1 and the collet chuck 10 attached thereto are stopped after rotating by 144 degrees.

Next, the collet chuck 10 is moved in the direction opposite to the X direction to loosen the grip 131, and then the work 99 is removed.

Next, the second workpiece is cut in the same manner. However, the centering tool 3c is used for centering in this case.

Hereinafter, each time one work is cut, the work spindle 1 and the collet chuck 10 are rotated by 144 degrees, and the centering tools 3a to 3e are a, c, e, b, and c, as shown in FIG.
d and a are used in this order.

That is, in this embodiment, when the rotation angle of the work spindle 1 required for cutting one work is 144 degrees or less,
Since the centering is performed by sequentially using every other centering tool as viewed in the rotation direction of the collet chuck 10, it is possible to cut five workpieces while the collet chuck 10 rotates twice. it can.

When the rotation angle of the work spindle 1 required for cutting one work is 216 degrees or less, the centering tools a to
By using e in the order of a, d, b, e, c, and a, five workpieces can be cut per 2.4 rotations of the collet chuck 10. Conventionally, when cutting five workpieces, five rotations of the collet chuck were required.

When the rotation angle of the work spindle 1 required for cutting one work is 288 degrees or less, as shown in FIG. 1, the centering tools 3a to 3e are changed to a, e, d, c, By using b and a in this order, five workpieces can be cut per four rotations of the collet chuck 10. Conventionally, when cutting five workpieces, five rotations of the collet chuck were required.

Furthermore, if the centering tools 3a to 3e are used for centering according to the above-mentioned use order, the tooth cutting portion 21 of each pinion cutter 2 can be used much more uniformly than in the past, so that the life thereof can be greatly extended. Can be.

As described above, the present embodiment has explained the middle cutting of the sector gear, but it is of course that the present invention can be applied to the finish cutting.

Embodiment 2 Another embodiment of the sector gear cutting method of the present invention will be described below.
explain.

In this embodiment, eight centering tools 3a to 3e are arranged rotationally symmetrically on the outer peripheral surface near the distal end of the collet chuck.
Except for using h (not shown), the same gear cutting machine as used in Example 1 is used.

Further, since the cutting operation itself of each work is the same as that of the first embodiment, the description is omitted. However, centering tools 3a-h
Are arranged in the rotation direction in the order of 3a, 3b, 3c,..., 3h.

In this embodiment, when the rotation angle of the work spindle 1 required for cutting one work is 135 degrees or less, the centering tools 3a to 3h are changed to a, d, g, b, e, h, and c. ,
Using f and a in this order, eight workpieces can be cut per three rotations of the collet chuck. Conventionally, only six workpieces could be cut for three rotations of the collet chuck.

If the rotation angle of the work spindle required for cutting one work is 225 degrees or less, the centering tools 3a to 3h
Can be used in the order of a, f, c, h, e, b, g, d, and a to cut eight workpieces per five rotations of the collet chuck 10. Conventionally, in this case, only five workpieces could be cut for five rotations of the collet chuck.

Further, when the rotation angle of the work spindle 1 required for cutting one work is 315 degrees or less, the centering tools 3a to
By using h in the order of a, h, g, f, e, d, c, b, and a, eight workpieces can be cut per seven rotations of the collet chuck 10. Conventionally, in this case, only seven workpieces could be cut per seven rotations of the collet chuck.

Also in the second embodiment, since the centering tools 3a to 3h are all used evenly, the wear of the pinion cutter 2 rotating synchronously with the collet chuck 10 is remarkably uniform.

Further, the collet chuck 10 may be always rotated by a predetermined rotation angle in cutting each work. That is, the work spindle 1 is provided with a rotary encoder to detect its rotation angle, or the photo interrupter detects that the next centering tool has reached a predetermined position and detects its rotation angle. A rotation angle between adjacent centering tools is detected. Then, by detecting an integral multiple of the detected rotation angle, the required rotation angle based on each of the above-described examples is obtained, and the start and stop of the rotation may be performed.

That is, according to the above embodiments, since the rotation control of the work spindle is simple, there is also an advantage that it can be easily applied to an existing gear cutting machine.

[Effects of the Invention] As described above, the sector gear cutting method of the present invention jumps over three or more centering tools arranged substantially rotationally symmetrically over the centering tool adjacent in the rotation direction. As described above, since the centering is performed by sequentially using all the centering tools, the following effects can be obtained.

(1) The cutting efficiency can be improved as compared with the conventional method. The rotation of the work spindle 1 in sector gear cutting is generally very slow, for example, about 1/3 rpm.

(2) Since the pinion cutter 2 can be used more uniformly, the problem of uneven wear of specific teeth, which has been a problem in the related art, can be improved. For example, the life of the pinion cutter can be extended several times that of the conventional art.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a cutting portion of a gear cutting machine using the cutting method of the present invention, and FIG. 2 is a sectional view thereof. FIG. 3 is a schematic plan view showing a work centering operation of the gear cutting machine of FIG.

Claims (1)

(57) [Claims] 1. A work comprising a sector gear rough finish member is gripped by a work gripping portion disposed at a tip end portion of a work spindle, and the work gripping portion is rotationally symmetrical about the axis of the work spindle around the work spindle. Three or more centering tools are arranged on the work spindle so that one of the centering tools is brought into contact with a tooth portion of the work, and gripping by the work gripping portion is completed, and the center of the work is adjusted. After performing the centering, the one centering tool is moved back to the original position, the work is rotated by the rotation of the work spindle, and a pinion cutter disposed near the work holding portion is moved to the work spindle. Rotating in synchronization with rotation and reciprocating in the axial direction to cause the pinion cutter to cut the teeth of the work, After stopping the tool and the pinion cutter, the work gripping part is loosened to remove the work and the work gripping part grips a new work, and the centering tool used immediately before and the centering tool used immediately before The centering tool is aligned with one of the remaining centering tools different from the centering tool adjacent to the work spindle in the rotation direction.Hereinafter, all the centering tools are rotated by a plurality of rotations of the work spindle. A sector gear cutting method characterized by sequentially using each workpiece to sequentially center the workpiece.