JP3002883B2 - Hob for internal gear machining - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hob for processing an internal gear.

[Conventional technology]

Most of the internal gear processing is performed using a pinion cutter, but is inferior to hobbing (using a carbide hob) in terms of processing efficiency.

In addition, barrel hobbs, cylindrical hobbs, spherical hobbs, and the like have been introduced and prototyped for internal gear processing, but have not been put to practical use due to difficulties in manufacturing.

In view of the above, the present applicant has previously proposed a continuously formed hob that is easy to manufacture.

In this continuous forming hob, the center line of the rough blade chip seating surface has an inclination angle with respect to a straight line perpendicular to the hob axis, and the inclination angle differs for each rough blade.

[Problems to be solved by the invention]

Since the continuous forming hob has the above-described configuration, not only the number of setup steps increases during production, but also the maintenance of accuracy,
It was difficult to improve.

The present invention has been made in view of the above circumstances, and an object of the present invention is to not only enable high-efficiency and high-precision machining of an internal gear, but also reduce the running cost. To provide a hob.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a single position type hob provided with a plurality of rough blades for performing rough cutting of the hob body and a finishing blade for performing tooth formation, wherein the finishing blade is provided with respect to the hob body. In addition to the assembly configuration in which the position can be adjusted in the radial direction, between the finishing blade and the hob main body, a taper surface comes in contact with the hob main body, and the finishing is performed by moving in the axial direction of the hob main body. A taper member that adjusts the position of the blade in the radial direction, and an adjusting screw that is engaged with the movement direction of the taper member, and is rotatably externally screwed into the hob main body so as to screw in the axial direction of the hob main body. And a radial position adjusting mechanism for adjusting the position of the finishing blade in the radial direction by moving the taper member by rotating the adjusting screw, and setting each rough blade and the finishing blade to the same thread with the hob shaft. While moving in the direction, Are you to the configuration also stepped in direction.

(Operation)

According to the above-described configuration, the internal gear machining hob has a rough blade and a finishing blade of a single position type, and rough cutting of a tooth groove portion and heavy-cutting of a tooth bottom portion, which are heavy cutting, are performed with a rough blade. The finishing process of the tooth profile that finally determines the precision of the gear to be machined is performed by the finishing blade, so that the processing of the internal gear can be performed with high efficiency and high precision.

Furthermore, each rough blade / finish blade is displaced from the same thread in the direction of the hob axis, and there is also a step in the radial direction, so rough blades with large wear will have uniform wear and accuracy must be guaranteed. The wear of the finishing blade is minimized, and the running cost of the tool can be reduced.

Furthermore, each finishing blade is individually adjusted in the radial direction by rotating the adjusting screw.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows the overall structure of the internal gear machining hob according to the present invention.

This internal gear machining hob is a five-piece hob and has three rough blades 1, 2, 3 and one finishing blade 4 per mouth.

Each of the finishing blades 4 has a blade 6 to which a cutting blade 5 is fixedly assembled to a hob main body 7 via a radial position adjusting mechanism 8.

The radial position adjusting mechanism 8 is configured as shown in FIG. 3, and a screw hole 9 provided in the hob body 7 in the axial direction thereof and a tapered surface portion 10 inclined in the axial direction of the hob body 7 are provided.
And a taper member 12 that abuts on the tapered surface portion at a tapered surface portion 13 and is inserted into the sliding groove portion 15 of the blade 6 so as to be slidable in the axial direction of the hob body 7, and is screwed into the screw hole portion 9. And a part in the circumferential direction is a tapered surface portion 13 of the tapered member 12.
Rotatable into the engaging groove 14 provided on the side, and a tapered member.
The adjusting screw 11 is engaged with the moving direction 12.

Accordingly, the driver 18 inserted into the driver through hole 17 provided in the collar 16 is engaged with the engagement concave portion 19 of the adjusting screw 11, and the adjusting screw 11 is rotated by the driver 18, so that the adjusting screw 11 The tapered member 12 is axially screwed and moves in the axial direction of the hob main body, whereby the blade 6 moves in the radial direction of the hob main body 7 due to the sliding contact of the tapered surface portions 13 and 10, and each finishing blade 4 Are individually adjusted to correspond to the cutting edge when the cutting edge is worn or minutely chipped.

Further, the cutting blade 5 of the finishing blade 4 is of a general shape and has an outer clearance angle and a side clearance angle.

The rough blades 1, 2, 3 that precede the finishing blade 4 generate the same chips at the respective cutting positions of the rough blades 1, 2, 3 so as to facilitate processing of the rough blade chip seating surface. ｛Hook (JISD4354) tooth line of truss line｝ Not present on S, threads D have appropriate steps D ₁ , D ₂ , D _{3 in} hob axis direction R, and radial step C ₁ , C ₂ and C ₃ are attached. In addition, the tooth height of the rough blade 3 is made larger than the tooth length of the finishing blade 4 so that the rough blade 3 performs the processing of the tooth bottom which does not require the tooth profile accuracy and has the largest cutting burden (see FIG. 4). .

These steps D _{1 to} D ₃ and C _{1 to} C ₃ are gear specifications (module,
The number of teeth, etc.), hob specifications (outer diameter, number of ports, number of grooves, etc.) and cutting conditions (cutting, feed) are determined in consideration of the cutting share of each cutting blade.

For example, 4M, Z81, hob outer diameter 27mm, number of mouths 5, number of grooves 20, depth of cut
8.8 mm, when the feed 1.0 mm / rev, is _{D 1 = 0.28mm, D 2 =} 0.16mm, D 3 = 0.05mm C 1 = 0.13mm, C 2 = 0.06mm, C 3 = 0.30mm.

The rough blades 1, 2, and 3 share the processing of the tooth groove portion which becomes severe in the hobbing processing of the internal gear. In addition, in terms of accuracy, about 50 μm in the axial direction and the radial direction is sufficient, so that a throw-away system is used. The insert has a rhombic shape and the rake angle is negative (−5 ° to 20 °), thereby forming an outer clearance angle and a side clearance angle of the cutting edge.

With this chip, four corners can be used.

In addition, it is also possible to use a rectangular parallelepiped chip for the rough blades 1, 2, and 3 for processing the tooth space portion.

FIG. 5 shows the cutting condition of each cutting blade (rough blades 1, 2, 3, and finishing blade 4) when the internal gear is processed using the internal gear processing hob according to the present invention.

Hobbing of the internal gear is a process performed by rotating the work and the hob continuously. Therefore, when the cross section in which each cutting edge performs processing is shown, it is superimposed and displayed as shown in FIG.

Here, the work rotation angle / hob 1 cutting edge is The amount of movement of one cutting edge in the hob axis direction is It is.

In this way, processing of severe parts is performed with the rough blades 1, 2, and 3 which are inexpensive and need not be adjusted, while the tooth forming is performed by the finishing blade 4 which is expensive and requires adjustment but can guarantee accuracy. Accordingly, the internal gear can be processed with high efficiency and high precision, and the running cost of the tool can be reduced.

[Example 1] A first five-port hob (carbide cutting blade, module 4) was used as a first sample.
Shown in the figure.

(B) Processing conditions Cutting speed: 150m / min Feed: 1.0mm / rev Depth of cut: 8.8mm (Full depth) Cutting direction: Conventional cut (upper → lower) Cutting oil: Organic molybdenum added oil 100 / min Work material: Module 4, number of teeth 81, pressure angle 20, tooth width 50, material
SCM445H (H _B 300) (b) gear accuracy J1S3 class (c) tooth surface roughness maximum roughness layer <6.3 [mu] m (d) Araha to reach tool life finishing blade wear = 0.2 mm; 1 chip (4
Corner) used, processed 30 pieces.

〔The invention's effect〕

As described in detail above, the internal gear machining hob according to the present invention is a single position type hob provided with a plurality of rough blades for performing rough cutting of the hob body and a finishing blade for performing tooth formation. In addition to the assembly configuration in which the position can be adjusted in the radial direction with respect to the hob main body, between each of the finishing blades and the hob main body, a taper surface comes in contact with the hob main body, and in the axial direction of the hob main body. A taper member that adjusts the position of the finishing blade in the radial direction by moving, and a screw that engages in the moving direction of the taper member and is rotatable from the outside so as to screw the hob body in the axial direction of the hob body. And a radial position adjusting mechanism that adjusts the position of the finishing blade in the radial direction by rotating the adjusting screw to move the taper member, and to adjust the rough blade and the finishing blade to the same thread. Not in the direction of the hob axis Causes and is characterized in that also stepped in the radial direction.

Therefore, each rough blade shares a severe processing portion, and the tooth forming can be performed by the finishing blade, so that the internal gear can be processed with high efficiency and high precision.

In addition, since each finishing blade is of an assembled configuration and its radial position can be adjusted individually by a radial position adjusting mechanism, each finishing blade can be adjusted according to its wear and minute defects. Since the replacement can be performed for each finishing blade, each finishing blade is individually performed in accordance with wear and tear, and the tool cost can be reduced as compared with a case where the blades are replaced all at once.

Since the adjustment of each finishing blade is performed by rotating each adjusting screw with a driver or the like, this adjusting operation is easy, and the combination of the screw and the tapered surface allows the radial direction of the finishing blade to be adjusted. Can be adjusted very finely.

In addition, since the rough blade has a cutting blade structure for equally sharing the cutting load, the running cost of the hob can be reduced.

[Brief description of the drawings]

1 is a plan view of one embodiment of the present invention, FIG. 2 is a longitudinal sectional view of the same, FIG. 3 is an enlarged view of a part III in FIG. 2, FIG. 4 is an explanatory view of a cutting blade configuration, and FIG. It is explanatory drawing which shows the cutting situation of each cutting blade at the time of internal gear machining. 1, 2, and 3 are rough blades, 4 is a finishing blade, 7 is a hob body, and 8 is a radial position adjustment mechanism.

Continuation of the front page (56) References JP-A-1-153218 (JP, A) JP-A-1-222816 (JP, A) JP-A-65-1527 (JP, U) JP-B-54-2716 (JP) , B2) (58) Field surveyed (Int.Cl. ⁷ , DB name) B23F 21/16

Claims (1)

(57) [Claims] In a single position type hob provided with a plurality of rough blades for rough cutting of a hob body and a finishing blade for forming teeth, the finishing blade can be adjusted in position in a radial direction with respect to the hob body. In addition to the assembled configuration, the finishing blades are in contact with the hob body on a tapered surface between each finishing blade and the hob body, and are moved in the axial direction of the hob body to adjust the position of the finishing blade in the radial direction. And an adjusting screw engaged with the moving direction of the tapered member, and rotatable from the outside, and screwed into the hob main body so as to screw in the axial direction of the hob main body. By providing a radial position adjustment mechanism for moving the taper member to adjust the position of the finishing blade in the radial direction by moving the rough blade and the finishing blade to the same thread in the hob axial direction, A step is also provided in the direction Hob gear cutting inner and said.