JPH02198711A - Hob for internal gear processing - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a hob for machining internal gears.

[Conventional technology]

Most of the machining of internal gears is done using a pinion cutter, but hobbing (using a carbide hob) is preferable in terms of machining efficiency.
inferior to

In addition, as for hobs capable of machining internal gears, barrel-shaped hobs, cylindrical-shaped hobs, spherical hobs, etc. have been proposed and prototyped, but they have not been put into practical use due to difficulties in production.

In view of these considerations, the present applicant previously proposed a continuous molding hob that is easy to manufacture.

In this continuous molding 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 each rough blade has a different inclination angle.

[Problem to be solved by the invention]

Since this continuous molding hob has the above-described configuration, not only the number of setup steps during manufacturing increases, but also it is difficult to maintain and improve accuracy.

The present invention has been made in view of the above circumstances, and its purpose is to provide a method for machining internal gears that not only enables high efficiency and high precision machining of internal gears but also reduces running costs. The aim is to provide a hob.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a single-position type hob in which a hob body is provided with a plurality of rough cutting blades for rough cutting and a finishing blade for tooth forming, in which the finishing blade is assembled into an assembled configuration. The hob body is equipped with a radial position adjustment mechanism that adjusts the position of the finishing blade in the radial direction, and the rough blade and finishing blade are not positioned on the same screw head, but are shifted in the hob axis direction, and there is also a step in the radial direction. This is the configuration with .

[For production]

According to the above configuration, this hob for internal gear machining has a single-position roughing blade and finishing blade, and rough cutting of the tooth groove area and finishing cutting of the bottom part of the blade, which are heavy cutting, are performed with the rough blade. Finishing of the tooth profile, which ultimately determines the precision of the gear being machined, is performed using a finishing blade, allowing for highly efficient machining of internal gears.
This can be done with high precision.

In addition, each roughing blade and finishing blade are offset from the same thread in the direction of the hob axis, and are also stepped in the radial direction, so the rough blade, which has a lot of wear, will wear evenly, and it is necessary to guarantee accuracy. Wear on the finishing blade is kept to a minimum, reducing tool running costs.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows the overall structure of a hob for machining internal gears according to the present invention.

This hob for machining internal gears has 50 hobs and has 3 rough edges 1, 2.3 and 1 finishing edge 4 per 10 hobs.

This finishing blade 4 includes a blade 6 to which a cutting edge 5 is fixed and is assembled to a hob body 7 via a radial position adjustment mechanism 8.

As shown in FIG. 3, the radial position adjustment mechanism 8 includes a screw hole 9 provided in the hob body 7 and a tapered surface 10, and an adjustment screw 11 is screwed into the screw hole 9. A part of the adjustment screw 11 is rotatably inserted into an engagement groove 14 provided on the tapered surface portion 13 side of the tapered member 12, and the tapered member 12 is inserted into the sliding groove portion 15 of the blade 6.
The tapered member 12 is slidably inserted into the hob body 7, and the tapered surface portion 13 of the taper member 12 is in sliding contact with the tapered surface portion 10 of the hob body 7.

Therefore, the driver 18 inserted into the driver through hole 17 provided in the collar 16 is inserted into the engagement recess 19 of the adjustment screw 11.
By rotating the adjustment screw 11 with the driver 18, the adjustment screw 11 is threaded in the hob axis direction to move the taper member 12, and the taper surface portion 13.1
The blade 6 is moved in the radial direction of the hob body 7 by the zero sliding contact and its position is adjusted, which corresponds to sharpening when the cutting edge is worn out or minutely chipped.

Further, the cutting edge 5 of the finishing blade 4 has a total shape and has an outer peripheral clearance angle and a side clearance angle.

The roughing blade 1.2.3 preceding the finishing blade 4 is used for each roughing blade 1, 2.
In order to generate uniform chips at each cutting position in 3 and to facilitate machining of the rough chip seating surface, the same screw thread (hob (J I)
5D4354) does not exist on the tooth trace line) S, and there is an appropriate step difference DI + D 2 in the hob axis direction R with respect to the thread trace S.
．． + D 3 is provided, and there are also radial steps C1, c
2+ C3 is attached. In addition, tooth profile accuracy is not required,
The tooth height of the rough blade 3 is made larger than the tooth height of the finishing blade 4 so that the rough blade 3 performs machining of the bottom of the tooth where the cutting load is the greatest (see Fig. 4).

These steps D1 to D3. C1 to C3 are gear specifications (module, number of teeth, etc.) and hob specifications (outer diameter).

From the number of openings, number of grooves, etc.) and cutting conditions (depth of cut, feed),
It is determined by considering the cutting share of each cutting edge.

For example, M4. Z81. Hob outer diameter 27° Number of openings 5. Number of grooves: 20. Depth of cut 8.8mm.

Sending 1. In the case of Omm/rev 1 DI = 0.28mm, D2 - 0.16mm.

D3-0.05m+s CI=0.13+s+s, C2-0,06++n.

C3-0,30 Dragon It is.

The rough blade 1.2.3 is responsible for machining the tooth groove portion, which is difficult to perform during hobbing of an internal gear.

Furthermore, in terms of accuracy, approximately 50 m in the axial and radial directions is sufficient, so the throw-away method is preferred.

The tip has a rhombic shape and has a negative rake angle (-5° to 20°) to form a peripheral clearance angle and a side clearance angle of the cutting edge.

This chip allows the use of four corners.

Note that it is also possible to use a rectangular parallelepiped-shaped tip for the rough blades 1, 2.3 in order to process the tooth groove portion.

FIG. 5 shows the cutting conditions of each cutting blade (rough blade 1.2°3, finishing blade 4) when machining an internal gear using the internal gear machining hob according to the present invention.

Hobbing of internal gears is a process in which the workpiece and hob continuously rotate. Therefore, when the cross sections processed by each cutting edge are shown, they are displayed overlapping each other as shown in FIG.

Here, the work rotation angle/hob 1 cutting edge is the amount of movement of the hob 1 cutting edge in the hob axial direction.

In this way, harsh parts can be machined with the roughing blades 1 and 2.3, which are inexpensive and do not require adjustment, while tooth forming can be performed with the finishing blade 4, which is expensive and requires adjustment, but can guarantee accuracy. This enables high-efficiency, high-precision machining of internal gears.
This is extremely practical as it can also reduce tool running costs.

[Example 1] Fig. 1 shows a prototype 50 hob (carbide cutting blade, module 4).

(a) Machining conditions Cutting speed: 150 Il/m1n Feed: 1. C1+m/rev depth of cut: 8
．． 8w (Pull depth) Cutting direction: Conventional cut (top-bottom) Cutting oil: Organic molybdenum-added oil 100 II/ml Cutting material: Module 4. Number of teeth: 81. Pressure angle 20°, tooth width 50, material S CM 445
H (Hs 300) (A) Gear accuracy JISB grade (C) Tooth surface roughness Maximum roughness layer 6.3 μm (D) Tool life Finishing edge wear - Rough edge until reaching 0.2 mm; 1 chip (4 Corner) used, 30 pieces processed.

〔Effect of the invention〕

As described in detail above, the internal gear machining hob according to the present invention is a single-position type hob in which the hob body is provided with a plurality of roughing blades for rough cutting and a finishing blade for tooth forming. In addition to the assembly configuration, the hob body is equipped with a radial position adjustment mechanism that adjusts the position of the finishing blade in the radial direction.
The rough cutting blade and the finishing blade are not located on the same thread cutting surface, but are shifted in the direction of the hob axis, and are also stepped in the radial direction.

Therefore, each roughing blade can perform the harsh machining part, and the finishing blade can perform tooth forming, resulting in high efficiency and high efficiency of internal gears.
High precision machining becomes possible.

In addition, the finishing blade has an assembled configuration and its radial position can be adjusted by a radial position adjustment mechanism, and the roughing blade has a cutting blade configuration that evenly shares the cutting load, thereby reducing the running cost of the hob.

4. Brief description of the drawings Figure 1 is a plan view of one embodiment of the present invention, Figure 2 is a longitudinal cross-sectional view of the same, Figure 3 is an enlarged view of the section ■ in Figure 2, and Figure 4 is an explanation of the cutting blade configuration. FIG. 5 is an explanatory diagram showing the cutting situation of each cutting blade during machining of an internal gear.

1.2.3 is a rough blade, 4 is a finishing blade, 7 is a hob body, and 8 is a radial position adjustment mechanism.

Claims (1)

[Claims] In a single-position hob equipped with a plurality of roughing blades for rough cutting the hob body and a finishing blade for tooth forming, the finishing blades are assembled and the position of the finishing blades is adjusted in the radial direction on the hob body. Internal gear machining characterized by providing a radial position adjustment mechanism so that each roughing blade and finishing blade are shifted in the direction of the hob axis instead of being positioned on the same thread, and a step is also provided in the radial direction. hobs.