JP2002172524A - Shaving cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve work surface roughness and work tooth profile precision. SOLUTION: The land width x of all lands 35a to 35f of a shaving cutter 30 is gradually reduced toward the dedendum E of a tooth flank 33. The surface pressure with which the lands 35a to 35f in the dedendum E of the shaving cutter 30 are brought in contact with a work tooth flank is increased in shaving.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaving cutter used for precisely finishing a gear tooth surface.

[0002]

2. Description of the Related Art A conventional shaving cutter 10 is shown in FIG.
As shown in FIG. 4, the gear 11 has a substantially disc shape with gear-shaped teeth 11 provided at regular intervals on the outer periphery. Further, as shown in FIG. The serrations 14 are formed. The ridges are referred to as lands 15 and the grooves are referred to as serration grooves 16. The ridges located at both ends of the lands 15 are the cutting blades 17. Here, the land width d of the serrations 14 is constant from the tip side to the root side of the shaving cutter 10. As shown in FIG. 5, the shaving cutter 10 having such a configuration has a fixed intersection angle α between the work shaft 22 and the shaving cutter shaft 12 so that the teeth 11 of the shaving cutter 10 and the teeth 21 of the work 20 are formed. And the tooth surface 23 of the teeth 21 of the work 20 is finished by a sliding action caused by the rotational movement.

[0003]

By using the shaving cutter 10 as described above, shaving is performed on the tooth surface 23 of the work 20 by setting the intersection angle α between the shaving cutter shaft 12 and the work shaft 22 to 15 °, for example. When you do
FIG. 6 shows a three-dimensionally analyzed scarf (cutting mark) shape of the cutting edge 17 of the serration 14 acting on the tooth surface 23 of the work 20. According to this scarf analysis, the work 20
At the position C of the meshing circle of the shaving cutter 10, since the scarf (cutting mark) 17a of the cutting blade 17 of the shaving cutter 10 is right beside the tooth trace at the position C of the meshing circle of the work 20, good sharpness can be obtained. Scarves (cut marks) 17a of the cutting blades 17 toward the tip A side and the root B side of 20
Becomes oblique to the direction parallel to the position C of the engagement circle of the work 20 (the direction just beside the tooth trace), so that the sharpness deteriorates, the surface roughness of the work 20 deteriorates, and the pressure angle increases. The error increases, and the tooth profile accuracy of the work 20 also decreases.

[0004] Further, as shown in FIG. 7, as in the case of shaving a shoulder gear as the work 20, the shaving cutter shaft 12 and the work shaft 22 are not provided because there is an obstacle 24 adjacent to the work 20. May not be able to ensure a sufficiently large intersection angle β. At this time, the scarf analysis when the intersection angle β is 5 ° is shown in FIG.
As shown in the figure, the inclination of the scarf (cut mark) 17a of the cutting blade 17 becomes larger than when the crossing angle is sufficiently large, and especially the root side of the shaving cutter 10 (the tip A side of the work 20). Therefore, the tendency is increased, and the above-mentioned problem is also increased.

[0005] The present invention has been made in view of the above problems, and has as its object to provide a shaving cutter capable of improving the surface roughness of a work and the precision of a work tooth profile.

[0006]

The present invention has the following features to attain the object mentioned above. That is, the shaving cutter according to claim 1 has a plurality of teeth provided at regular intervals on an outer periphery, and the tooth surface of the teeth is provided with serrations. Are characterized by the same changing tendency toward each other in the tooth height direction. Here, all land widths change with the same change tendency, for example, when all land widths decrease toward the tooth tip side or root side, or when all land widths decrease at the same position with all land widths. From the same position toward the root of the tooth,
It means things like getting smaller. When the shaving cutter having such a configuration is used, where the land width is small, the surface pressure when the land comes into contact with the tooth surface of the work can be increased and the sharpness can be improved. In addition, by reducing the land width, uniform accuracy can be obtained over the entire tooth surface of the work.

[0007] The shaving cutter according to claim 2 is
The width of the land decreases from the position of the meshing circle toward the root of the tooth. With this configuration, it is possible to increase the surface pressure when the land contacts the tooth surface of the work on the tooth tip (the root of the shaving cutter) of the work, and the tooth tip side portion of the tooth surface of the work can be increased. However, since sufficient sharpness can be obtained, it is effective particularly in the case of processing a shoulder gear in which the crossing angle between the shaving cutter axis and the work axis cannot be made sufficiently large during shaving processing.

[0008] The shaving cutter according to claim 3 is
The width of the land decreases from the position of the meshing circle toward the tooth tip. With this configuration, it is possible to increase the surface pressure when the land comes into contact with the tooth surface of the work also on the tooth root (the tip of the shaving cutter) of the work, and the tooth side of the tooth surface of the work can be increased. However, since sufficient sharpness can be obtained, it is effective particularly in the case of processing a shoulder gear, for example, in a case where the inclination of the scarf becomes large even at the root side of the tooth surface of the work.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an enlarged view of a main part of a shaving cutter according to a first embodiment of the present invention, and FIG. 2 is an enlarged view of a main part of a shaving cutter according to a second embodiment of the present invention.

The shaving cutter 30 according to the first embodiment of the present invention has a substantially disk shape, and is provided with a plurality of teeth 31 at regular intervals along the outer periphery. Tooth 3
As shown in FIG. 1, for example, five grooves are provided at regular intervals on one tooth surface 33, and serrations 34 are formed. The grooves are referred to as serration grooves 36, and the five serration grooves 36 The formed six peaks are lands 35a to 35f. Lands 35a-3
The ridge between 5f and the serration groove 36 is a cutting edge 37.

As shown in FIG. 1, the land width x of all the lands 35 (35a to 35f) of the serrations 34 of the shaving cutter 30 according to the first embodiment is the maximum at the edge of the tooth tip D side of the shaving cutter 30. It becomes smaller gradually from the tooth tip D side to the tooth root E side and becomes the minimum at the tooth root E side edge. Lands 35a to 35f
Of the cutting edge 3 lands 35b~35e not located at both ends in the tooth width direction of the tooth surface 33 located in the respective opposite end edges
The land width x is reduced so that the ridges 7 and 37 approach each other at equal intervals, and the lands 35b to 35e have the shape of an isosceles trapezoid in a front view. Lands 35a to 35
Of the f, the lands 35a and 35f located at both ends of the tooth surface 33 in the tooth width direction have cutting edges 37 formed only at one end thereof, and the ridge line at the other end becomes an end surface of the shaving cutter 30. The land width x is reduced so that only the blade 37 approaches the ridge line on the other end side, and the ridge line on the other end side has a linear shape extending on a plane orthogonal to the shaving cutter axis, and the lands 35a, 35f are formed. Is an unequal leg trapezoid having a right angle in a front view.

According to the shaving cutter 30 of the first embodiment configured as described above, the serrations 3
Since the fourth land width x are formed as will become gradually smaller toward the tooth root E side of the teeth 31 of the shaving cutter 30, when subjected to shaving the work, poor sharpness of the cutting edge 37 The land width x can be reduced on the tip side of the workpiece (near the root E side of the shaving cutter 30), and the surface pressure when the land 35 comes into contact with the workpiece can be increased. The sharpness of the side portions is obtained, and uniform accuracy can be obtained over the entire tooth surface of the work. Further, when the crossing angle between the shaving cutter shaft 22 and the work shaft 12 cannot be sufficiently large, such as when the work is a shoulder gear, and it is difficult to make the sharpness uniform on the tip side of the work, The shaving cutter 30 according to the present embodiment is particularly effective.

The shaving cutter 40 according to the second embodiment of the present invention has substantially the same configuration as that of the first embodiment, and is different from the first embodiment only in the shape of the land 45. The same parts are denoted by the same reference numerals, and description thereof is omitted.

The shaving cutter 4 according to the second embodiment
0 indicates that the land width y of all the lands 45 (45a to 45f) of the serration 34 is maximum at the position F of the meshing circle of the shaving cutter 40 as shown in FIG. As it goes to the tip D side and the root E side, it gradually becomes smaller and the edge of the tip D side and the root E
It becomes minimum at the side edges. Lands 45a-4
5f, the lands 45b to 45e that are not located at both ends in the tooth width direction of the tooth surface 33 are equal to each other as the cutting blades 37, 37 located at the respective end edges move toward the tip D side and the root E side. The land width y decreases so as to approach at intervals, and the shapes of the lands 45b to 45e form oblique hexagons when viewed from the front. Also, of the lands 45a to 45f, lands 45a, 45 located at both ends of the tooth surface 33 in the tooth width direction.
As for f, the cutting edge 37 is formed only on one end side, and the ridge line on the other end side becomes the end face of the shaving cutter 40, so that only the cutting edge 37 faces the tooth tip D side and the root E side of the tooth surface 33. Accordingly, the land width y decreases so as to approach the ridge line on the other end side, and the ridge line on the other end side becomes a linear shape extending in a plane orthogonal to the shaving cutter axis, and the shapes of the lands 45a and 45f are formed. Is a pentagonal shape having a right angle in a front view.

According to the shaving cutter 40 configured as described above, the surface pressure of the land 45 is increased as the cutting edge 37 becomes farther from the position F of the best engaging circle, and the work tooth surface is increased. The uniformity of sharpness can be achieved on the tip side and root side of the work, for which uniformity of sharpness is difficult. This is especially useful when the shoulder gear is to be used, such as when processing shoulder gears, and the inclination of the scarf becomes large even at the root side of the tooth surface of the work. Is obtained.

In this embodiment, the land width has a certain width at the position where the land widths x and y are minimum. However, the land widths x and y gradually become smaller and the land widths x and y become smaller. y may be eliminated. In this case, for example, in the shaving cutter 30 according to the first embodiment, the shape of the land 35 is an isosceles triangle, and the shape of the land 45 of the shaving cutter 40 according to the second embodiment is a rhombus.

In the first embodiment, the land width x decreases as the shaving cutter 30 moves from the tip D to the root E. However, the root width of the work (the tip of the shaving cutter 30) is reduced. On the other hand, when the sharpness is severely deteriorated on the D side), the land width x may be reduced from the root E side of the shaving cutter 30 to the tip D side.

In this embodiment, the lands 35,
Although the length of the cutting blades 37, 37 located at both ends of the 45 is the same for both, the length of the cutting blade 37 may be different. In this case, in the first embodiment, the shape of the land 35 is an unequal leg trapezoid. Further, one of the cutting edges 37, 37 formed at both ends of the lands 35, 45 may be formed in a straight line extending on a plane perpendicular to the shaving cutter axis. In this case, in the first embodiment, the shape of the land 35 is an unequal leg trapezoid having a right angle.

In the second embodiment, the land width y is formed so as to become gradually smaller as the land F approaches the tooth tip D side and the tooth root E side from the meshing circle position F. However, the present invention is not limited to this. Instead, the land width y may be constant on one side from the position F of the meshing circle.

Further, in this embodiment, the cutting blade 37 is formed in a straight line, but is not limited to this and may be a curved line.

[0021]

According to the present invention, all land widths change in the tooth height direction, and the changing tendency is in the same direction, so that the land width is reduced in accordance with the position where sharpness deteriorates. By doing so, the sharpness can be made uniform in the portion where the sharpness has deteriorated, whereby the uniform sharpness can be obtained over the entire tooth surface of the work, and the precision of the work after processing can be kept good. Further, since the land width is reduced from the position of the meshing circle toward the root of the tooth, the sharpness of the tooth surface of the work can be obtained uniformly on the tip side of the work, and the land width can be further reduced. Since it decreases in the direction of the tooth tip from the position of the engagement circle, it is possible to obtain a uniform sharpness of the tooth surface of the work even on the root side of the work, which is particularly effective when processing a shoulder gear. .

[Brief description of the drawings]

FIG. 1 is an enlarged view of a main part of a shaving cutter according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of a shaving cutter according to a second embodiment of the present invention.

FIG. 3 is a schematic view showing a general shaving cutter.

FIG. 4 is an enlarged view of a main part of the shaving cutter in FIG. 3;

FIG. 5 is a schematic view showing a state of shaving processing of a general shaving cutter.

FIG. 6 is a schematic view showing a state of shaving a shoulder gear.

FIG. 7 is a scarf analysis diagram when the intersection angle between the shaving cutter axis and the work axis is 15 °.

FIG. 8 is a scarf analysis diagram when the intersection angle between the shaving cutter axis and the work axis is 5 °.

[Explanation of symbols]

30, 40 Shaving cutter 31 Teeth 33 Tooth surface 34 Serration 35 (35a to 35f), 45 (45a to 45f) Land 36 Serration groove 37 Cutting edge x, y Land width F Position of meshing circle

Claims (3)

[Claims] 1. A shaving cutter having a plurality of teeth provided at regular intervals on an outer periphery thereof, and having serrations provided on tooth surfaces of the teeth, wherein all land widths of the serrations extend in a tooth length direction. A shaving cutter characterized in that the shaving cutters change with the same changing tendency. 2. The shaving cutter according to claim 1, wherein the land width decreases from the position of the meshing circle toward the root of the tooth. 3. The shaving cutter according to claim 1, wherein the land width decreases from a position of a meshing circle toward a tooth tip.