JPH0347710Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a rolling die for gears with crowning that can manufacture teeth with crowning with extremely high precision.

[Conventional technology]

BACKGROUND ART Conventionally, rolling dies for gears having crowning have been processed by processing carbide tool materials and the like using a grinding machine using a disc grindstone e, as shown in FIG. Specifically, by grinding a disc grindstone e of an appropriate diameter whose circumferential cross section is cut into a bottomed V-shape (see Fig. 14), or by swinging a small diameter disc grindstone e in an arc shape. By grinding while grinding, a die root part a having a concave arc shape in the direction perpendicular to the tooth thickness and a die tooth tip part b having a concave arc shape in the direction perpendicular to the tooth thickness are processed, and the die tooth surface part c was formed into a reverse crowning (in this specification, the concept is opposite to "crowning"), and a rolling die for gears having crowning was manufactured.
At this time, both corners at the upper end of the entire tooth height of the rolling die are formed as arc-shaped corners d with a small radius, and it is possible that these arc-shaped corners d and the entire tooth height are formed at the same time. many. Also, the die teeth are
It is formed by a disc grindstone e, and has an arc shape in the direction perpendicular to the tooth thickness, and the approximate center line of the full tooth height in the direction perpendicular to the tooth thickness has a concave arc shape in the direction perpendicular to the tooth thickness.
In this specification, this is referred to as the die tooth pitch line p.
It is called. The actual die pitch circle is a straight line.

Teeth with crowning can be obtained by machining with such a rolling die, as shown in Figs. 16 and 17. A tooth tip portion of the product is processed at the die root portion a of the rolling die, thereby forming teeth having crowning on the circumference of the product.

In particular, the point is that the tooth of the product is formed in an arc shape in the direction perpendicular to the tooth thickness when viewed from the tooth thickness direction, but the tooth tip of the product is pressed at the die root a of the rolling die. The teeth are formed under low pressure, and the direction perpendicular to the tooth thickness of the teeth is substantially horizontal, thereby producing teeth with crowning as shown in FIG. 19.

[The problem that the idea attempts to solve]

Incidentally, in such a rolling die, the teeth with the crowning have a symmetrical spindle shape when viewed from above, and continuous circular arcs are formed, but the amount of crowning w (see Fig. 19)
There has also been a need to increase the accuracy of teeth with crowning, or to process teeth with crowning to a higher degree of accuracy.

Moreover, if the die tooth tip part b has a concave arc shape,
The contact surface with the gear molding part of the workpiece makes two-point contact, and if there are protrusions such as burrs on the contact surface of the gear molding part (raw material), the position of the chamfer becomes unstable and the pitch of the crowning teeth may shift. There was also the problem that tooth profile accuracy could not be stably maintained.
In this way, when biting occurs, it hits a point, which has the disadvantage of rapid wear and short rolling die life.

[Means to solve the problem]

Therefore, in order to solve the above problem, the inventor conducted extensive research and came up with the idea of making the die root part concave with an appropriate radius of curvature in the direction perpendicular to the tooth thickness.
The direction perpendicular to the tooth thickness of the die tooth tip is a horizontal plane, and the height position of the die tooth tip is the maximum depth position of the concave portion of the die tooth root, and the die tooth tip has the full die tooth height. A rolling die for a gear with a crowning formed on the die body is made of a die tooth with a reverse crowning on the tooth trace on the face, or a concave shape with an appropriate radius of curvature is formed in the direction perpendicular to the tooth thickness at the root of the die. The direction perpendicular to the tooth thickness of the die tooth tip is a horizontal plane, and the height position of the die tooth tip is
The die has the full tooth height at the maximum depth position of the concave portion of the die tooth root, and the tooth trace of the die tooth surface is formed in a reverse crowning, and the corner portion between the die tooth tip and the die tooth surface is By using this rolling die for gears, which has crowning formed on the die body, the die teeth have arcuate corners with a small radius formed over the entire length in the direction perpendicular to the tooth thickness. , a gear with crowning can be manufactured with extremely high precision, and the above-mentioned problem has been solved.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 13.

A is a rolling die, and 1 is a die body of the rolling die A, which has a substantially rectangular cross section, is linear in the longitudinal direction, and is made of a carbide tool material or the like.

2 is a die tooth, which is formed from a die tooth base portion 2a, a die tooth tip portion 2b, and a die tooth surface portion 2c. The tooth trace 2c of the die tooth 2 has a reverse crowning in _one direction. That is, as shown in FIG. 13, crowning refers to adding an appropriate bulge in the direction of the tooth trace 3b of the tooth surface 3a of the tooth 3 of the gear manufactured using the rolling die A to improve tooth contact. This is for purposes such as: Also, the amount of crowning lol
represents the amount of bulge, and in FIG. 13, refers to the bulge from the end to the middle. Therefore, reverse crowning refers to an arcuate depression in this specification.

In addition, the die root portion 2a has a concave shape with an appropriate radius of curvature in the direction perpendicular to the tooth thickness (longitudinal direction),
In addition, the direction perpendicular to the tooth thickness of the die tooth tip 2b forms a horizontal plane, and the height position of the die tooth tip 2b is as follows.
Maximum depth position of the concave portion of the die root portion 2a
It is configured to have the die total tooth height h at Dmax.

In addition, the die tooth tip portion 2b and the die tooth surface portion 2
An arcuate corner 2d with a small radius is formed over the entire length in the direction perpendicular to the tooth thickness at the corner with c (see FIG. 6).

Moreover, the die tooth tip 2b has a constricted central position when viewed from a plane perpendicular to the die tooth tip 2b (see FIGS. 1 and 2).

Next, there are two types of embodiments for manufacturing the rolling die A for gears having such a crowning, and this first embodiment has a concave portion in the die root portion 2a as shown in FIG. By removing the triangular cross-sectional pieces on both sides of the upper side, the die tooth surface portion 2c is formed flat so that the die has the total tooth height h at the maximum depth position Dmax, and the die tooth tip portion 2b and the die tooth surface portion 2c, an arcuate corner portion 2d with a small radius is formed over the entire length in the direction orthogonal to the tooth thickness at the corner portion (6th
(see figure). At this time, an arcuate corner 2d has already been formed near the maximum depth position Dmax of the recess of the die dedendum 2a.

In addition, as shown in FIGS. 7 and 8, the second embodiment has a die body 1 which has a substantially rectangular cross section, has a flat upper surface, and is linear in the longitudinal direction. By grinding the disc grindstone e directly from the top (see Fig. 7), or by grinding while swinging the small diameter disc grindstone e in an arc shape, it is possible to improve the width of the rolling die A. central position,
In other words, the maximum depth position of the die tooth base 2a
The rolling die A of the present invention can be manufactured by grinding so that Dmax (see FIG. 3) corresponds only to the total tooth height h of the rolling die A of the disc grindstone e.

In addition, since the die teeth 2 are formed of a disc grindstone e, the approximate center line of the die total tooth height h in the direction perpendicular to the tooth thickness has a concave arc shape in the direction perpendicular to the tooth thickness. is referred to as the die tooth pitch line p ₀ in this specification (see FIG. 3). The actual pitch circle of the rolling die A is linear.

4 in the figure is a shaft portion provided at the end of the gear having teeth 3.

[Effect of idea]

First, in the invention of claim 1, the die root portion 2a has a concave shape with an appropriate radius of curvature in the direction perpendicular to the tooth thickness, and the die tooth tip portion 2b has a horizontal plane in the direction perpendicular to the tooth thickness. The height position of 2b is the maximum depth position Dmax of the recess of the die tooth base 2a.
By using a rolling die for gears having a crowning formed on the die main body 1, the die tooth 2 has a die total tooth height h and the tooth trace 2c ₁ of the die tooth surface portion 2c is formed in a reverse crowning. Firstly, gears with crowning can be manufactured with extremely high precision, secondly the biting of the material can be stabilized, and thirdly the durability of the rolling die can be improved.

To explain these effects in detail, first, by using the present invention, a gear having a crowning with extremely high tooth profile accuracy can be manufactured. To explain this effect in detail, conventionally, as shown in FIGS. 14 and 15, the die root part a has a concave arc shape in the direction perpendicular to the tooth thickness, and a concave arc shape in the direction perpendicular to the tooth thickness. When rolling is performed using a rolling die consisting of a die tooth tip b, as shown in Fig. 16, the arc-shaped die tooth tip b presses the product extremely. As a result, as shown in FIG. 18, the pressed member bulges slightly upward, and since there is a crowning amount w at the center position, there is almost no bulge, and as a result, , although it is a little extreme, the 19th
Teeth with crowning as shown in the figure were formed, which had the disadvantage of reducing tooth profile accuracy, but the rolling die of the present invention has crowning with a horizontal plane in the direction perpendicular to the tooth thickness of the die tooth tip 2b. By using a rolling die for gears, the die tooth tips 2b do not press in an arc shape as in the past, but in order to press in a flat shape.
The situation shown in FIGS. 19 to 19 is eliminated, and furthermore, the height position of the die tooth tip 2b is set at the maximum depth position Dmax of the concave portion of the die tooth base 2a and has the die total tooth height h. By doing so, the position where the crowning amount w of the tooth with crowning of the manufactured product is maximum is the position where the tooth surface contacts the most. This is the same as a conventional tooth with a crowning, and it is possible to provide a rolling die for a gear with a crowning that can be formed with extremely high tooth profile accuracy as a whole.

In addition, the rolling die for gears having a crowning according to the present invention has a flat tooth tip 2b, so that the biting between the product (material) and the rolling die according to the present invention is caused by flat contact. Therefore, the tooth profile accuracy can be stably maintained with minimal pitch deviation.

If surface contact can be made in this way, there is an advantage that the tool can be used more stably and the tool life can be improved compared to point contact.

Furthermore, when a gear with a shaft portion 4 is rolled using the rolling die of the present invention, the material cannot be pressed with the concave arc-shaped die tooth tip b of the rolling die as in the conventional method. Therefore, if there is a necessary minimum step m between the root part of the rolled tooth 3 and the shaft part 4 (see Fig. 11), a crowned tooth without interference with the shaft part 4 can be formed. There are some effects that can be done.

In the device of claim 2, in the device of claim 1, an arcuate corner portion with a small radius is formed over the entire length in the direction orthogonal to the tooth thickness at the corner portion between the die tooth tip portion 2b and the die tooth surface portion 2c. By forming 2d, in particular, the dedendum portion of the tooth height base of the gear after rolling becomes arcuate, albeit slightly, and the tooth profile can be manufactured strongly. To explain this effect in detail, due to the presence of the arcuate corner 2d,
When manufactured by rolling, these locations become arcuate portions at the base positions on both sides of the tooth profile of the gear, and unlike simple corner portions, no stress concentration occurs, thereby making the tooth profile stronger.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a perspective view of the invention, Fig. 2 is a plan perspective view of Fig. 1, and Fig. 3 is a sectional view of the invention. Fourth
The figures are a cross-sectional view taken in the direction of the arrows in FIG. 2, FIG. 5 is a partial sectional view of the process of manufacturing the present invention, FIG. 6 is a partial perspective view of the present invention manufactured according to FIG. 5, and FIG. 8 is a partial sectional view of another embodiment of the manufacturing process of the present invention, FIG. 8 is an enlarged sectional view taken in the direction of the arrows in FIG. 7, and FIG. 9 is a rolling process using a pair of the present invention. A perspective view of the state, Figure 10 is a side view of Figure 9, Figure 11 is a sectional view taken along the line P-P in Figure 10, and Figure 12 is Figure 10 Q.
-Q arrow sectional view, Fig. 13 is a partially enlarged perspective view of a tooth manufactured using the present invention, Fig. 14 is a partially sectional view of a conventional rolling die in the grinding state, and Fig. 15
The figure is a partially enlarged perspective view of a conventional rolling die, No. 16.
The figure is a sectional view of the conventional rolling process, Figure 17 is an enlarged sectional view of the main part of Figure 15, and Figure 18 is Figure 17Y.
FIG. 19 is an enlarged perspective view of a part of a tooth manufactured using a conventional rolling die. 1...Dice body, 2...Dice teeth, 2a...
Die tooth base, 2b...Die tooth tip, 2c...
Die tooth surface portion, 2c ₁ ...Tooth trace, 2d...Circular corner, Dmax...Maximum depth position, h...Die total tooth height.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) The die root portion has a concave shape with an appropriate radius of curvature in the direction perpendicular to the tooth thickness, the die tooth tip portion has a horizontal plane in the direction perpendicular to the tooth thickness, and The height position is the maximum depth position of the concave portion of the die tooth base, and the die body has die teeth that have the full tooth height of the die, and the tooth trace of the die tooth surface portion is formed in a reverse crowning manner. A rolling die for gears with a crowning. (2) The die root portion has a concave shape with an appropriate radius of curvature in the direction perpendicular to the tooth thickness, and the die tooth tip portion has a horizontal plane in the direction perpendicular to the tooth thickness, and the height position of the die tooth tip portion is equal to the die tooth The die has the full tooth height at the maximum depth position of the concave portion of the base, the tooth trace on the die tooth surface is formed in an inverted crowning, and the tooth thickness at the corner between the die tooth tip and the die tooth surface is perpendicular. A rolling die for gears having a crowning, characterized in that the die body is formed with die teeth having arcuate corners with a slight radius over the entire length in the direction.