JPH0335833A - Manufacture of gear with crowning - Google Patents

Abstract

PURPOSE:To work a crowning gear with high precision by form rolling a material to be worked having a bulged part in the middle with a form rolling die having specified tooth dimensions. CONSTITUTION:The periphery at the middle position in the lengthwise direction of a cylindrical gear body 4 of the material B to be worked is a bulged part 4a having a diameter larger than those at both ends. This bulged part is form- rolled by a pair of form rolling dies A which is provided with the teeth 2 of total tooth depth composed of a recessed, cylindrical deddendum 2a in the direction at right angles to the tooth thickness, a horizontal addendum 2b in the same direction and a tooth flank with an inverse crown, and in which the height and position of the addendum 2b is set at the deepest position of the recessed part of the deddendum part 2a. In this way, the manufacturing precision of the crowning gear can be improved and an amount of crowning can be increased drastically.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a gear having crowning, which allows teeth having crowning to be manufactured with extremely high precision and also by which the amount of crowning can be increased.

[Conventional technology]

Traditionally, teeth with crowning have existed, but
When this is enlarged, as shown in Fig. 24, both ends of the tooth in the direction perpendicular to the tooth thickness bulge out slightly, and as a result, the central position of the maximum crowning amount W0 is slightly depressed when viewed from the side. It was in a state. This is what happens in Figure 19.

As shown in Fig. 20, when the die root part a has a concave arc shape in the direction perpendicular to the tooth thickness and the die tooth tip part has a concave arc shape in the direction perpendicular to the tooth thickness, the tooth trace is reverse crowned (this specification In the book “
When a die tooth surface C having a concave arc-shaped die tooth tip C is rolled with a pair of rolling dies (see Fig. 21), The gear material is pressed extremely, and as a result, the pressed member bulges slightly upward, and there is a crowning amount W at the center position, as shown in FIGS. 22 and 23. Therefore, it does not bulge out,
This became more noticeable as the tarowning two increased.

Further, in the conventional rolling die for gears having a crowning, as shown in FIG. 19, a carbide tool material or the like is processed by a grinding machine using a disc grindstone d. Specifically, by grinding a disc grindstone d of an appropriate diameter whose circumferential cross section is cut into a bottomed ■ shape (see Fig. 19).
, or by grinding while rubbing a small-diameter disc grindstone d in an arc shape, a die root part a having a concave arc shape in the direction perpendicular to the tooth thickness and a die tooth tip having a concave arc shape in the direction perpendicular to the tooth thickness. A rolling die for a gear with a crowning was manufactured by processing the tooth surface part C and forming a reverse crowning (see Fig. 20). d 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. Hereinafter, it will be referred to as the die tooth pitch line p. The actual die pinch circle is linear.

Teeth with crowning can be obtained through processing using such rolling dies because, as shown in Figs. 21 and 22, the root of the gear in the direction perpendicular to the tooth thickness is concave when viewed from the tooth thickness direction. Although the product is formed into an arc shape, the tip of the tooth of the product is formed with a small pressing force at the die root a of the rolling die, and the tooth tip is formed in a substantially horizontal direction in the direction perpendicular to the tooth thickness. As a result, gears with crowning as shown in FIG. 24 were machined using these tools.

[Problems to be Solved by the Invention] Therefore, gears having crowning processed by rolling as described above have a problem that the m-shape accuracy in measurement of tooth thickness, etc. decreases, and furthermore, it is difficult to increase the amount of crowning w0. As a result, both ends of the tooth tip bulge out and the center becomes concave), and both ends of the tooth tip sag in the tooth width direction, so extra thickness is provided at the tooth tip to make it larger than the required tooth height. after that,
There was an inconvenience in that it required polishing to achieve the required tooth height.

[Means to solve the problem]

Therefore, the inventor worked diligently to solve the above problem.

As a result of repeated research, the invention was developed by making the circumference of the cylindrical gear body of the workpiece at an intermediate position in the longitudinal direction a bulge having a larger diameter than both ends of the longitudinal direction, and then A die tooth root portion having a concave arc shape in a direction perpendicular to the tooth thickness, a die tooth tip portion having a horizontal surface shape in a direction perpendicular to the tooth thickness, and a die tooth surface portion having an inverse crowning, the height of the die tooth tip portion being a height of the die tooth tip portion. The position is at the maximum depth position of the concave portion of the die tooth base, and the cylindrical shape with the bulge is used with a pair of rolling dies for gears having a crowning and having die teeth with the full tooth height of the die. By adopting a manufacturing method for gears with crowning that involves forming a plurality of teeth with crowning on the circumferential surface of the gear body,
Teeth with crowning can be manufactured with extremely high precision, crowning IW6 can be made significantly large, and the above-mentioned problems have been solved.

〔Example〕

Hereinafter, the manufacturing method of the present invention will be explained based on the drawings.

First, the configuration of the rolling die A used in the manufacturing method and the configuration of the workpiece B will be described.

A is a rolling die, as shown in Figure 1O and Figure 11,
The die body 1 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 includes a die tooth root portion 2a and a die tooth tip portion 2b.
and a die tooth surface portion 2c. The tooth groove 2c1 direction of the die teeth 2 is reverse crowned.

That is, the tooth trace 2c+ of the die tooth surface portion 2c is formed as an arc-shaped depression opposite to "crowning".

Further, 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), and the die tooth tip portion 2b has a horizontal plane in the direction perpendicular to the tooth thickness. The height position of the tip portion 2b is configured to have the total tooth height of the die at the maximum depth iDmax of the recessed portion of the die root portion 2a.

Furthermore, an arcuate corner 2d having a small radius is formed at the corner between the die tooth tip 2b and the die tooth flank 2C over the entire length in the direction orthogonal to the tooth thickness.

Further, the die tooth tip 2b has a constricted central position when viewed from a plane perpendicular to the die tooth tip 2b. The die teeth 2 are formed by a disc grindstone and have 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 pin.
It is called the nochi line p0. The actual die Spinoch circle is a straight line.

B is a workpiece, and in the embodiment, a cylindrical gear body 4 is integrally formed at the end of the shaft portion 3).

Although not shown, the cylindrical gear body 4 alone may serve as the workpiece B, and is not limited to the embodiment.

Reference numeral 4a denotes a bulge, which is formed so that the circumference of the central position of the cylindrical gear body 4 in the longitudinal direction has a larger diameter at both end portions in the longitudinal direction than at other portions. The bulge 4
There are multiple embodiments of a, and in the first embodiment, as shown in FIG. has been done.

In addition, as shown in FIG. 8, the second embodiment of the bulging portion 4a has a trapezoidal mountain shape in cross section so that the circumference at the center position in the longitudinal direction of the cylindrical gear body 4 is maximum. It is formed to disappear at both ends or in the middle in the longitudinal direction.

Furthermore, as shown in FIG. 9, in the third embodiment of the bulging portion 4a, the cylindrical gear body 4 has the maximum circumference at the center position in the longitudinal direction, and has a chevron-shaped arc shape in cross section. It is formed so that it disappears at both ends or in the middle of the direction. In this case, the diameter φ2 at the center position is larger than the end diameter φ.

Next, the manufacturing method will be explained. First, as shown in FIG. 1, the workpiece B is rotatably mounted on a gear rolling machine. Next, as shown in FIG. 2, while the pair of rolling dies A and the die teeth 2.2 of A are facing each other,
The die teeth 2 are moved from side to side with respect to each other.
The die tooth tip 2b bites into the bulge 4a of the workpiece B (see FIGS. 2 and 4), and when it is further moved (see FIG. 5), the die tooth tip 2b At this time, the outer circumference of the cylindrical gear body 4 is also pressed and rolled while pressing the bulging portion 4a, and furthermore, this rolling tooth becomes deeper (see Fig. 6), and in the final stage of movement ( (see Fig. 3), and gears as shown in Fig. 7 are rolled.

Specifically, the teeth 5 of the gear include a root portion 5a and a tooth tip portion 5b.
and a tooth surface portion 5c. The tooth trace 5c+ direction of the tooth 5 is crowned.

As shown in FIG. 16, crowning refers to the creation of an appropriate bulge in the tooth trace 5c+ direction of the tooth surface portion 5c of the tooth 5, and is intended to improve tooth contact. Further, crowning I W + or w2 represents the amount of bulge, and in FIGS. 17 and 18, refers to the bulge from the end to the intermediate maximum bulge position. This crowning is symmetrically formed in a spindle shape in a direction perpendicular to the tooth thickness.

Further, the longitudinal direction of each of the root portion 5a and the tip portion 5b is formed to be parallel to the axis S of the main body (see FIGS. 14 and 15).

〔Effect of the invention〕

In the present invention, the intermediate position circumference in the longitudinal direction of the cylindrical gear main body 4 of the workpiece B is made into a bulged portion 4a having a larger diameter than the both end portions in the longitudinal direction, and then the tooth thickness is orthogonally The die tooth tip portion 2b has a die tooth root portion 2a having a concave arc shape in the direction, a die tooth tip portion 2b having a horizontal plane in a direction perpendicular to the tooth thickness, and a die tooth flank portion 2c having an inverse crowning.
The height position is the maximum depth position Dmax of the concave portion of the die root portion 2a, and the height position is the maximum depth position Dmax of the concave portion of the die root portion 2a. By adopting a method of manufacturing a gear with a crowning in which a plurality of teeth 5 with a crowning are formed on the circumferential surface of the cylindrical gear body 4 with the bulging portion 4a, firstly, the gear with a crowning can be manufactured with high precision. Second, the amount of crowning can be significantly increased, and third, the manufacturing method can be extremely simplified as in the conventional method.

To explain these effects in detail, conventionally, as shown in FIGS. 19 and 20, the die dedendum part a has a concave arc shape in the direction perpendicular to the tooth thickness, and the die dedendum a has a concave arc shape in the direction perpendicular to the tooth thickness. When the tip of the die tooth is formed, the tooth surface C has a reverse crowning.
When rolling is performed with a pair of rolling dies consisting of
As shown in the figure, the tip of the die teeth in the shape of a concave arc presses the workpiece extremely, and as a result, as shown in Figures 22 and 23, the pressed part is The member bulges slightly upward, and the central position has a crowning, so it hardly bulges out.As a result, teeth with crowning as shown in Fig. 24, although a little extreme, are formed, and the gear However, according to the construction method of the present invention, in particular, the rolling die A has the following drawbacks:
The die tooth tip portion 2b is formed in a horizontal plane in the direction perpendicular to the tooth thickness. Since the bulged portion 4a is formed with a larger diameter than that of the
As shown in FIGS. 4 to 7, even if the outer circumference of the cylindrical gear body 4 of the workpiece B is pressed with the horizontal die tooth tip 2b, the tooth thickness of the teeth 5 of the product is Orthogonal tooth tip 5
There is no bulging at both ends of the tooth 5, and the tip portion 5b of the tooth 5 can finally be processed into a substantially flat shape as shown in FIG. At this time, the swollen portion 4a is specially designed so that it flows suitably as a material in the direction of increasing the amount of crowning (see FIGS. 17 and 18).
The process shown in FIGS. 4 to 7 is extremely uneven in the drawings, but this action is clarified.

Therefore, unlike the conventional method shown in FIG. 24, both ends of the tooth tips do not bulge, and according to the manufacturing method of the present invention, the workpiece B can be formed using the new rolling die A. Cylindrical gear body 4
There is an advantage that the tip portion 5b of the tooth 5 of the gear can be processed into a substantially flat shape by a simple manufacturing method in which the bulge portion 4a is formed and then processed.

At the same time, Crowning 1Wl, WE (Fig. 17).

(see Fig. 18), even if the tooth tip 5 of the gear tooth 5 is increased.
There is an advantage that b can be processed into a substantially flat shape. To explain this point in detail, in the past, when trying to increase the tarrowing agitation w0 (see Fig. 24), both ends of the tooth tip bulged out and the center became depressed), and both ends in the tooth width direction also sagged. For,
However, there were inconveniences such as the need to provide extra thickness at the tip of the tooth so that it was larger than the required tooth height, and then perform polishing to finish the tooth to the required tooth height. With the manufacturing method, as mentioned above, there is no dent in the center of the tooth tip 5b, the tooth profile accuracy is extremely high, and the crowning 1l
Since the bottom shape of the tooth 5 can be shaped to have a crowning with large Wl and Wfi, there is no need for corrective polishing of the tooth tip 5b, which has the advantage of improving manufacturing efficiency and lowering manufacturing costs.

The ability to process in this manner has the effect of significantly improving accuracy when measuring the tooth thickness of a gear as a guide for determining the accuracy of gears.

As described above, in the production method of the present invention, the amount of tarowning w
Even if l, w, (see Figures 17 and 18) are increased,
The essence of the invention still lies in improving the accuracy of gears. Due to this increase in the amount of tarrowing w,, w,
It also has the advantage of making the contact with the tooth surface even better.

Moreover, the manufacturing method of the present invention changes the shape of the workpiece B,
After that, processing is performed using a new rolling die A, but since this process is no different from conventional rolling processing, gears with crowning can be manufactured with high precision just as easily as before. There are great advantages that can be achieved.

In addition, in the case of a gear with a shaft 3, the material is not pressed by the tip of the concave arc-shaped die teeth of the rolling die, as is the case with conventional gears, so the rolled teeth are If there is a necessary minimum level difference m between the root part 5a of No. 5 and the shaft part 3 (see Fig. 7).
This has the effect of making the crowning teeth bottom-shaped without interfering with the shaft part 3, and furthermore, prevents damage to the shaft part 3.
Alternatively, the diameter of the shaft portion 3 is not made wastefully small, which is extremely suitable in terms of strength, and there is also the advantage that the material can be used effectively.

[BRIEF DESCRIPTION OF THE DRAWINGS] The drawings show embodiments of the present invention, in which Figure 1 is a schematic perspective view before processing of the manufacturing method of the present invention, and Figure 2 is a schematic perspective view of the manufacturing method of the present invention. FIG. 3 is a schematic side view of the process in progress, FIG. 4 is a schematic side view of the completed process of the manufacturing method of the present invention, and FIG. 4 is FIG. 2 IV
-TV cross-sectional view 1. Figure 5 Figure 6 is a sectional view of the main part at a further rear stage than the case in Figure 4, Figure 7 is the same as Figure 3 ■-■
8 and 9 are partial side views of another embodiment of the workpiece, FIG. 1O is a perspective view of a rolling die used in the manufacturing method of the present invention, and FIG. Figure 10 is a plan perspective view, Figure 12 is an enlarged sectional view of Figure 10, Figure 13 is Figure 11P.
-P arrow sectional view, FIG. 14 is a perspective view of a gear with a shaft manufactured by the manufacturing method of the present invention, FIG. 15 is a side view with a partial cross section of FIG. 14, and FIG. An enlarged perspective view of a tooth with a crowning manufactured by the manufacturing method, 1st
Figures 7 and 18 are enlarged plan views of teeth with crowning manufactured by the manufacturing method of the present invention, Figure 19 is a sectional view of a conventional rolling die in a manufacturing state, and Figure W420 is a diagram of a conventional rolling die. FIG. 21 is a cross-sectional view of a rolling state of a gear with a conventional crowning, FIG. 22 is an enlarged cross-sectional view of the main part of FIG. 21, and FIG. 23 is a view taken from the Q-Q arrow in FIG. 22. The enlarged sectional view and FIG. 24 are partially enlarged perspective views of teeth manufactured by the conventional manufacturing method ←, 7° using a conventional rolling die. A...Rolling die, 2...Die tooth, 2a...Die tooth base, 2b...
...Die tooth tip, 2c...Die tooth surface, B...Workpiece, 4...Cylindrical gear body, 4a... Swelling part, DIa... Maximum depth position, h... Full die tooth height, 5.
·····teeth. Patent Applicant Yamada Seisakusho Co., Ltd. Figure 4 4a Figure 6 Figure 8 Figure 5 Figure 7 Figure 14 Figure 3 Figure 16 Figure 15 Figure 17

Claims (1)

[Claims] (1) The circumference at an intermediate position in the longitudinal direction of the cylindrical gear body of the workpiece is made into a bulge having a larger diameter compared to both ends of the longitudinal direction, and then a concave circle is formed in the direction perpendicular to the tooth thickness. It has an arc-shaped die tooth root, a die tooth tip having a horizontal plane in a direction perpendicular to the tooth thickness, and a die tooth surface having an inverted crowning, and the height position of the die tooth tip is equal to the die tooth root. At the maximum depth position of the concave part, a pair of rolling dies for gears with crowning and having die teeth with the full tooth height of the die are used to crown the circumferential surface of the cylindrical gear body with the bulge part. A method for manufacturing a gear having a crowning characterized by forming a plurality of teeth having a crowning.