JPS6043217B2 - Method for rolling crown teeth on workpieces such as gears and a pair of flat dies - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for rolling a crown tooth onto a workpiece such as a gear or a spline.

Conventionally, the tooth surface of gears, splines, etc.
, is formed into a curved surface as shown in Figure 2 (such teeth will be referred to here as crown teeth).

With respect to the tooth trace direction O' of the tooth 1, which is parallel to the rotation axis of the workpiece, the center part lb of the tooth has a shape that bulges out from both ends lc, that is, it has a crown shape.

This bulging amount α is about 10μ. In this way, by using crown teeth for the teeth of gears, etc., it is possible to absorb errors in the meshing of gears, etc., and to prevent the teeth from seizing by sufficiently distributing lubricating oil between the meshing teeth. It becomes possible.

Incidentally, although it is well known that gears and the like can be manufactured by rolling machining using a flat die, a method of generating crown teeth by this rolling machining has not been attempted in the past.

When trying to create a crown tooth by the rolling process of a flat die, it is easy to imagine that each tooth surface 2a of each tooth 2b of the flat die 2 can be formed into a crown tooth of a gear, etc., as shown in FIG. Corresponding to No. 1, both ends of the tooth surface are shaped to bulge out from the center, that is, shaped like a drum.

However, in practice, it is extremely difficult to form each tooth 2b of the flat die 2 into such a shape. The present invention provides a novel rolling method that can generate crown teeth on a workpiece even when using a conventional ordinary flat die, and a pair of flat dies having a novel structure suitable for carrying out the rolling method. is intended to provide.

The gist of the present method invention for achieving the above object is that the tooth array surfaces of a pair of flat dies are parallel to each other, the axes thereof are parallel to each other, and the teeth of each flat die are parallel to each other. A workpiece such as a gear, characterized in that the pair of flat dies is moved in a state where the tooth trace is slightly inclined with respect to the tooth trace of the tooth of the workpiece to be rolled. The invention consists in a method of rolling a crown tooth.

The method invention described above can also be achieved by using a conventional ordinary flat die and by changing the manner in which the flat die is attached to a rolling device from the conventional one. If a die is used, the rolling process can be carried out by attaching the flat die to the rolling device in the same manner as in the conventional method. The gist of the second invention is to provide one flat die with teeth having a tooth trace helix angle slightly larger than the tooth trace helix angle of the workpiece, and a tooth trace having a tooth trace helix angle slightly smaller than the tooth trace helix angle of the workpiece. The present invention relates to a pair of flat dies for rolling a crown tooth, which includes another flat die having teeth having a helical angle.

The present invention will be specifically described below with reference to the embodiments illustrated in FIGS. 4 to 7. The embodiment shown in FIG. 4 1, ■ shows a rolling method for rolling a spur gear and a flat die as an example.

In Fig. 4 1, ■, 3a and 3b are a pair of flat dies for the rolling process of spur gears that have been commonly used in the past, that is, the tooth traces of each tooth 3a'' and 3b''
, a pair of flat dies that are perpendicular to O2, and 4 is a workpiece such as a gear. The pair of flat dies 3a, 3b and the workpiece 4 are mounted on a rolling device (not shown).

4. As shown in FIG. 1, the workpiece 4 is rotatably mounted in the direction of the arrow, and a pair of flat dies 3a, 3b are placed on both sides of the workpiece 4 so as to narrow the workpiece 4, and have different reciprocating dead centers. mounted in position. The pair of flat dies 3a, 3b has tooth arrangement surfaces 3e, 3f parallel to each other as shown in FIG. 41, and their respective axes 01, 02 as shown in FIG. are parallel to each other, and each tooth 3a'',
Tooth 4 of workpiece 4 to be rolled with tooth trace 3b
Rolling (not shown) is performed in a state where the flat dies 3a and 3b are tilted by a slight angle β with respect to the tooth trace of a, that is, with each axis 01 and 02 of each flat die 3a and 3b being tilted by an angle β with respect to the flat die moving direction Z. attached to the device.

In the rolling method according to the present invention, the workpiece 4 and the pair of flat dies 3a, 3b are mounted on the rolling device as described above, and then, as in the conventional method, as shown in FIG. Flat dice 3a, 3
b is moved in a direction perpendicular to the rotation axis 0 of the workpiece 4 and to the reciprocating dead center on the opposite side, as shown by the dashed line in the figure, and thereby the peripheral surface of the workpiece 4 is moved. A crown tooth 4a is created.

According to the above-mentioned rolling method, as shown in FIG. , S2 are in different directions with respect to the tooth trace O'' of the tooth 4a, that is, at an angle β
Then, the workpiece 4 is subjected to creative processing while being inclined by one β.

In the figure, 3d shows the tooth surface of the workpiece 4 created by the teeth 3a'' of one flat die 3a, and 3c shows the tooth surface of the workpiece 4 created by the teeth 3b'' of the other flat die 3b. There is. Therefore, the crown tooth 4a created by the rolling method according to the present invention is as shown in FIG.

That is, the tooth surface of the tooth 4a is composed of two curved surfaces (involute curved surfaces) 4b and 4c, and the central portion of the tooth 4a where the curved surfaces 4b and 4c intersect bulges out from both ends thereof. Therefore, strictly speaking, this tooth surface is composed of two curved surfaces, and is not one curved surface as in the conventional example shown in FIGS. 1 and 2, but as mentioned above, the tooth surface Since the amount of bulge at the center of the curve is only about 10μ, the curved surface made up of these two curved surfaces is extremely close to the one curved surface.
This curved surface sufficiently achieves the purpose of crown teeth, which is to make the central part of the tooth surface bulge out from both ends of the tooth surface. Although the above-mentioned embodiment shows the case where a spur gear is rolled, the case where a helical gear is rolled is also similar to the above.

However, in this case, the flat die is for rolling helical gears,
In other words, a die in which each tooth trace has a constant inclination with respect to a direction perpendicular to the die axis is used. Furthermore, although the above embodiment is about a rolling method performed using a conventional flat die, the method of the present invention uses a pair of flat dies having a novel configuration shown in FIG. It can be implemented even if

Figure 6 1, ■ shows mutually compatible flat dies.

The flat die 3a shown in FIG. 6 1 is provided with a 3a'' having a tooth helix angle γ slightly larger than the tooth helix angle γ of the workpiece 4 (γ=0 in the case of a spur gear) by an angle β. Another flat die 3b shown in FIG. When carrying out the above rolling method using the pair of flat dies 3a and 3b, the fourth
As shown in Figure ■, each axis of each flat die 3a, 3b is 0.
It is not necessary to install the shafts 01, 02 on the rolling device at an angle with respect to the moving direction Z of the flat dies 3a, 3b.
In other words, you just have to wear it in the same way as before.

By simply installing it in this way, the tooth traces of each tooth 3a'', 3b'' can be set at an angle β or -β with respect to the tooth trace of the tooth 4a of the workpiece 4.
Can only be tilted. Therefore, if a pair of flat dies with this new structure is used, there is no need to make any design changes to the conventional rolling device when installing the flat dies to the rolling device, and the installation itself is easy. . As is clear from the specific description of the above embodiments, according to the rolling method according to the present invention, when installing a pair of flat dies in a rolling device, the pair of flat dies are are parallel to each other, their respective axes are not parallel to each other, and the tooth traces of the teeth of each flat die are slightly inclined to the tooth traces of the teeth of the workpiece to be rolled. A crown tooth can be created on a workpiece by a simple operation, and the desired purpose can be achieved.

Further, according to the pair of flat dies according to the present invention, the helix angle of the tooth trace is simply changed, and the tooth surfaces of the teeth themselves are flat, making it easy to process the teeth. There is no difficulty involved in forming the three-dimensionally changing tooth surface shown in the figure. It also has the advantage of being easy to attach to a rolling device. Brief explanation of the drawings Figure 1 is a perspective view of a gear etc. having a crown tooth surface, Figure 2 is a sectional view taken along the line ■-■ in Figure 1, and Figure 3
The figure is a perspective view of the main part of an imaginary flat die with special teeth for rolling gears etc. with the teeth shown in Fig. 4,
Figures 4 to 7 show examples of the present invention, Figure 4 1 is an explanatory diagram showing the method of the present invention for rolling gears, etc. using a pair of flat dies, and Figure 4 5 is an enlarged plan view of the state in which each tooth of a pair of flat dies creates a tooth surface of a gear, and FIG. FIG. 7 is a plan view showing the die, and a perspective view showing teeth of a workpiece rolled by the method of the present invention.

1...Tooth, 1a...Tooth surface, 1b...
...Central part, 1c...End part, α...Bulge amount, 0...Center line of workpiece, O''...
...Tooth trace of the workpiece, β, -β...Inclination angle between the tooth trace of the flat die and the tooth trace of the workpiece, γ, -γ...
... Helix angle of the teeth of the workpiece, Sl, S2 ... Tooth line of the teeth of the flat die, 2 ... Flat die, 2a ...
...Tooth surface, 2b...Tooth, 3a, 3b...
...flat die, 3a'', 3b''...teeth, 3c
...Tooth profile created by tooth 3b'', 3d...
...Tooth profile created by tooth 3a'', 3e, 3f・
...Tooth arrangement surface, 4...Workpiece (gear)
, 4a...teeth, 4b, 4c...teeth surface.

Claims (1)

[Claims] 1. By moving a pair of flat dies in opposite directions to each other and in a direction perpendicular to the rotation axis of the workpiece while narrowing the workpiece, In the rolling method for generating and imparting teeth, the tooth arrangement surfaces of the pair of flat dies are parallel to each other, their axes are parallel to each other, and the tooth traces of the teeth of each flat die are rolled. A method for rolling crown teeth onto a workpiece such as a gear, characterized in that the pair of flat dies are moved in a state slightly inclined with respect to the tooth trace of the workpiece to be machined. How to process. 2. One flat die equipped with teeth having a tooth trace torsion angle slightly larger than the tooth trace torsion angle of the workpiece, and a die having teeth having a tooth trace torsion angle slightly smaller than the tooth trace torsion angle of the workpiece. A pair of flat dies for rolling crown teeth, consisting of one flat die.