JPS6018509B2 - Flat die for crown tooth rolling - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flat die for rolling crown teeth on workpieces such as gears and splines.

Conventionally, the tooth surfaces of gears, splines, etc.
It is formed into a curved surface as shown in Figure 2 (such a tooth will be referred to here as a crown tooth). As shown in the figure, the tooth surface la of the crown tooth 1 has a shape in which the center part lb of the tooth bulges out from both ends lc with respect to the center line 0' of the tooth 1 which is parallel to the rotation axis of the workpiece. In other words, it has a crown shape.

This bulging amount Q is generally about 1 tsubo. 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. Become.

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

When trying to create crown teeth by rolling with a flat die, it is easy to imagine that each tooth surface 2a of each tooth 2b of the flat die 2 can be shaped like a gear, etc., as shown in FIG. Corresponding to the crown tooth 1, the tooth surface has a curved shape in which both ends bulge out from the center, that is, in the shape of a drum.

However, in practice, it is extremely difficult to process each tooth 2b of the flat die 2 into such a curved surface shape. The present invention
To provide a flat die with a new configuration that is easy to manufacture and can create and impart desired crown teeth to a workpiece. The gist of the present invention for achieving the above object is that the tooth thickness of each tooth becomes thinner from one side in the middle direction of the die toward the pond side, and the directions of the thinning are opposite to each other between the dies. A pair of flat dies for crown tooth rolling, characterized by:

The present invention will be specifically described below with reference to the embodiments shown in FIGS. 4 to 8.

Figure 4 1, 3a and 3b are a pair of flat dies,
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).

As shown in the figure, a workpiece 4 is mounted rotatably in the direction of the arrow, and a pair of flat dies 3a, 3b are mounted on both sides of the workpiece 4 so as to sandwich the workpiece 4, and at the position of the reciprocating dead center. Ru. The pair of flat dies 3a and 3b are mounted on the rolling device so that their tooth arrangement surfaces 3e and 3f are parallel to each other and parallel to the rotation axis of the workpiece 4. be done. By the way, the above pair of flat dies 3a, 3b
The basic structure of each tooth is the same, as shown in FIG.

In other words, each tooth 3a', 3b'' of each flat die 3a, 3b
Well, like the conventional flat die teeth, they are arranged at equal intervals along the longitudinal direction of the die so as to be orthogonal to the longitudinal direction of the die, but the tooth thickness W of each tooth is set in the middle direction, that is, as shown in the figure. This causes a change in the tooth trace direction. That is, the die is configured so that the tooth thickness W decreases linearly from one side toward the other side in the middle direction of the die, that is, the planar shape is tapered. Tooth thickness W on one side of each tooth, and tooth thickness W on the other side
The difference of 2 is determined based on the relationship with the bulge amount Q shown in FIG. If the pair of flat dies 3a, 3b are arranged to face each other with the workpiece 4 in between, as shown in FIG. When attached to the die, one side of the die is S; the other end is S'
Then, the thick end of the teeth of the flat die 3a is located on the S' side, and the thick end of the teeth of the other flat die 3b is located on the S' side.
It will be located on the side.

By the way, the pair of flat dies 3a and 3b have a wide side U with a bite that bites into the workpiece 4 and a relief side NI that escapes from the workpiece 4 after rolling. However, if we consider this directionality, the directions in which the tooth thickness of each tooth 3 and 3b' becomes thinner between both flat dies 3a and 3b should be opposite to each other. become.

The method of rolling using the pair of flat dies 3a and 3b having the above configuration is the same as the conventional method, and as shown in FIG.
a, 3b in a direction perpendicular to the rotational axis of the workpiece 4 and to the opposite reciprocating dead center as shown by the dashed line in the figure. crown tooth 4
Create and grant a. A pair of flat dies 3a according to the present invention,
3b, each tooth 3a', 3 of the double flat die 3a, 3b
b' is created so that it tapers in a different direction when the tooth of the workpiece is viewed in plan (FIG. 7) with respect to the tooth surface of the tooth 4a of the workpiece 4 to be created.

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. ing. Therefore, the crown tooth 4a created by rolling using the flat die according to the present invention becomes as shown in FIG.

That is, the tooth surface of the tooth 4a is composed of two curved surfaces (impolute 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. Since the amount of bulge of the part is only about 1 degree, the curved surface made up of these two curved surfaces is infinitely close to the above-mentioned 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. As is clear from the specific description of the above embodiments, it is possible to create and impart desired crown teeth to a workpiece by rolling using a pair of flat dies according to the present invention. Since the change in the tooth thickness of each tooth is linear, the teeth can be easily machined, and there is no difficulty involved in forming a tooth whose tooth thickness changes two-dimensionally as shown in FIG. As mentioned above, the pair of flat dies according to the present invention can achieve the intended purpose.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a tooth such as a gear having a crown tooth surface, Fig. 2 is a sectional view taken along the low zero line in Fig. A perspective view of the essential parts of an imaginary flat die with teeth, FIG. 4 1 is an explanatory diagram showing a general method for rolling gears etc. using a pair of flat dies, FIG. 1 and 5D are plan views of essential parts of the flat dies 3a and 3b, respectively, and FIG. 6 is a right side view of the flat dies 3a and 3.
Fig. 7 is a perspective view of the main part of b, and Fig. 7 shows each tooth 3a' of a pair of flat dies.
, A plan view of the state in which the tooth surface of a 3-injured gear is created,
FIG. 8 is a perspective view showing teeth of a gear or the like rolled using the flat die according to the present invention. 1...Tooth, la...Tooth surface, lb...
・Central part, lc... end, Q... bulge amount, 0... center line, 2... flat die,
2a...Tooth surface, 2b...Tooth, 3a, 3
b...Flat die, 3a', 3b'...teeth, 3c...teeth 3
Tooth profile created from b'', 3d...Tooth 3a
Tooth profile created by ', 3e, 3f...Tooth arrangement surface, 4... Workpiece (gear), 4a...
Teeth, 4b, 4C. ...Tooth surface. Figure 1 Figure 2 Figure 3 Figure 4

[11 Figure 4 m] Figure 5 [11 Figure 5 m1 Figure 7 Figure 6 Figure 8

Claims (1)

[Claims] 1. A pair of crown tooth rolling plain dies, characterized in that the tooth thickness of each tooth becomes thinner from one side to the other side in the width direction of the die, and the directions of thinning are opposite to each other between the dies.