JP2002139118A - Rolling element for traction drive and manufacturing method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively provide a rolling element for traction drive whose periphery integrally has a gear for power transmission of different mechanical performance. SOLUTION: For the joint of a gear part 20 to the periphery of a body part 10, with adhesive applied to at least either of joint surfaces of the body part 10 and the gear part 20, shrink fitting and/or freeze fitting joint the gear part 20 to the periphery of the body part 10 and forms an adhesive layer 30 between the joint surfaces.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traction drive rolling element used as a power transmission component in a toroidal type continuously variable transmission used as, for example, a transmission for an automobile, and a traction drive rolling element such as this. The present invention relates to a method for manufacturing a moving body.

[0002]

2. Description of the Related Art In various automotive parts, it is required to further reduce the weight of a vehicle in order to further improve fuel efficiency in consideration of reducing the influence on the environment. In the toroidal type continuously variable transmission as well, structural measures such as reducing the unit size by integrally molding a disk disposed in the center portion and providing an output gear on the outer peripheral portion of the disk (rolling element) have been made. Is being done.

[0003] As described above, the structure of the rolling element having the output gear provided on the outer peripheral portion thereof is different from the mechanical performance required for the rolling surface portion and the gear portion. As described in JP-A-63139, the rolling element and the gear are separated and integrated by plastic deformation or welding, or as described in JP-A-11-141637. After integrally forming the gears and carburizing, unnecessary carburized layers are removed, or carburizing is performed in a state of carburized or semi-carbonized,
Alternatively, an example is introduced in which the depth of the hardened layer of the rolling surface portion and the gear portion of the rolling element is changed by performing a conditionally different induction hardening.

[0004]

However, in the rolling element described in Japanese Patent Application Laid-Open No. H11-63139, there is a possibility that a crack may occur at the time of integration, and a sectional area for integrating the rolling element and the gear. May be restricted. In addition, the rolling element described in Japanese Patent Application Laid-Open No. 11-141637 has a problem that it is difficult to obtain a uniform hardened layer depth.

On the other hand, as a general fastening method for integrating the rolling element having a separate structure and the gear, there is a method such as shrink-fitting or press-fitting. May not be able to meet certain conditions,
There is a problem that it is difficult to provide it at a low price while being restricted by the shape, and the development of a structure and a joining method for integrating the rolling element and the gear with high strength and low cost has been developed. This has been a problem in reducing the size and weight of the device.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problem in the manufacture of a conventional traction drive rolling element having a power transmission gear having different mechanical performances on the outer peripheral portion. It is an object of the present invention to provide an inexpensive high-strength traction drive rolling element integrally provided with a power transmission gear so that a gear portion can be easily and stably fastened to the outer peripheral side of the traction drive.

[0007]

According to a first aspect of the present invention, there is provided a traction drive rolling element provided on the outer peripheral side of a main body having a rolling surface for transmitting power by a traction drive. A traction drive rolling element comprising a power transmission gear unit fastened, wherein the gear unit is fitted to the main body in a state where the temperature is higher than the main body, and a temperature difference between the two is substantially eliminated. And a structure in which an adhesive layer is formed between the fastening surfaces of the main body and the gear portion. Means to solve the problem.

As one embodiment of the traction drive rolling element according to the present invention, in the traction drive rolling element according to the second aspect, the interference between the main body portion and the gear portion is zero with respect to the size of the fastening surface. In the rolling element according to the third aspect, the interference between the main body and the gear portion is 0.037 to 0 with respect to the size of the fastening surface. In the rolling element according to the fourth aspect,
6. The rolling element according to claim 5, wherein the main body and the gear portion are axially positioned by a fastening surface between the main body portion and the gear portion or a positioning means formed at an end of the fastening surface. And a caulking piece formed at one end of the fastening surface of the gear portion is caulked to the other of the main body portion and the gear portion. In the rolling element according to claim 6, the rolling element for traction drive is a toroidal type. It is characterized in that it is applied to an output disk for a continuously variable transmission.

In the method for manufacturing a traction drive rolling element according to the present invention, the main body portion and the gear portion are fastened in a state where predetermined processing and heat treatment have been performed in advance. Thereafter, a predetermined processing is performed, and the embodiment is characterized in that, in the method of manufacturing a rolling element according to claim 8, the gear portion is heat-treated by a press quench method.

[0010]

FIG. 1 shows an example of the structure of an output disk for a toroidal type continuously variable transmission as an example of a traction drive rolling element according to the present invention.
The output disk 1 shown in FIG. 1 is a power transmission having a ring-shaped outer periphery of a main body 10 provided with rolling surfaces 11 and 12 whose surfaces are aligned with each other and having a number of teeth 21 meshing with gears (not shown). Gear portion 20 is fastened via an adhesive layer 30, and the gear portion 20 is fitted to the main body 10 at a higher temperature than the main body 10 with a gap therebetween.
When the temperature difference between the main body 10 and the gear 20 substantially disappears, a tightening force is generated.
Both are joined with a predetermined strength by the adhesive force of the adhesive layer 30.

FIG. 2 shows an example of a manufacturing process of such a traction drive rolling element. The main body 10 and the gear section 20 of the rolling element 1 are made of, for example, JIS.
After raw processing into rough shapes using alloy steels for machine structural use for sintering specified in G4052, G4102-4106, etc., heat treatments such as carburizing and quenching and tempering and carbonitriding and quenching and quenching are respectively performed.

That is, the main body 10 and the gear 20
Are processed separately and heat-treated,
It is possible to obtain a cured layer by an optimal heat treatment using an optimal material in consideration of each function. Specifically, since high rolling fatigue strength is required for the rolling surfaces 11 and 12, a deep hardened layer is formed on the main body 10 by carburizing, quenching and tempering, and the gear 20 is A shallower hardened layer is formed. At this time, in heat treatment of the gear portion 20 having a ring shape, it is desirable to adopt a press quench method as described in claim 8 from the viewpoint of suppressing heat treatment distortion.

Next, each fastening surface is machined so that the temperature of the gear portion 20 is higher than that of the main body portion 10 during insertion (heating of the gear portion 20 and / or main body portion 10).
By cooling, the two members can be fitted to each other with a gap therebetween, and furthermore, the fitting surface is processed so as to form a tight fit when the temperature difference between the two members is eliminated after the fitting.

The finishing dimensions of the fastening surface at this time are as follows:
As described in claim 2 and claim 3, d-D
(Where d: outer diameter of the fastening surface of the main body portion 10, D: inner diameter of the fastening surface of the gear portion 20) is defined as
Of the fastening surface inner diameter (D) is preferably 0% or more and 0.153% or less, more preferably 0.037% or more.
More desirably, the range is 0.100% or less. If the interference is less than 0% of the inner diameter D, a gap may be formed between the two members, so that sufficient fastening strength may not be obtained. %
In the case of exceeding, it is necessary to increase the temperature difference at the time of fitting, so that the workability is deteriorated and the work time tends to be longer, and also the tensile stress is generated in the gear portion 20. It may be deformed and cause a subtle change in meshing with a gear arranged outside the figure.

At the time of this fastening surface processing, as described in claim 4 or claim 5, if necessary, a positioning means such as a positioning step or a flange is formed, or both members are caulked. It is desirable to process a caulking piece for fixing. At this time, these positioning means and swaging pieces can be provided not only on the main body 10 but also on the gear 20 side. Depending on the position and shape of these positioning means and swaging pieces, it is desirable to carry out rough processing in advance at the stage of raw processing in consideration of these.

As such a positioning means, a step portion 1 is used.
FIG. 3 shows an example in which 3 and 22 are formed on the fastening surfaces of the main body 10 and the gear section 20, respectively. FIG. 4 shows an example in which the collar 14 is formed at the end of the fastening surface of the main body 10 as the positioning means. At this time, by forming a chamfer 23 between the fastening surface of the gear portion 20 and the end surface on the flange side, a slight step or round portion is formed at the corner between the fastening surface of the main body portion 10 and the positioning collar 14. Even if
Accurate positioning becomes possible. At this time, there is no particular problem even if a positioning flange is provided at the end of the gear portion 20 side fastening surface.

By forming such positioning means, the gear portion 20 can be quickly and accurately and stably arranged at a predetermined position of the main body portion 10, and the two members can be positioned during positioning. Problems such as fastening due to the absence of the temperature difference and hardening of an adhesive described later are prevented.

By forming the steps 13, 22 as positioning means on the fastening surface as shown in FIG. 3, the positioning collar 14 is provided at the end of the fastening surface as shown in FIG. As compared with the case of disposing, the exposure of the collar 14 can be avoided, and no extra space is required, and the appearance is good.

FIG. 5 (a) shows a crimping collar 1 at an axially opposite end of a positioning collar 14 provided on a fastening surface of the main body 10.
FIG. 5B shows an example in which 5 (caulking pieces) are formed. After the gear portion 20 is fastened, as shown in FIG. A load (for example, 1000 N) is applied to cause plastic deformation, and the gear portion 20 is fixed between the positioning flange 14 and the gear portion 20. Thus, not only can the fastening force be further improved, but also if the fastening force and the bonding strength by the adhesive cannot withstand the transmission torque, the gear portion 20 is separated from the main body portion 10. No more. In addition, such a caulking brim 15 is formed at the stage of raw processing before heat treatment, and a hardened layer is formed on the surface thereof. deep. In addition, when the main body 10 is cooled at the time of fitting, it is desirable to perform caulking after returning to room temperature to avoid breakage of the caulked piece due to low-temperature embrittlement.

FIGS. 6A and 6B show an example in which a positioning flange 24 and a caulking flange 25 are provided at both ends of the fastening surface of the gear portion 20. FIG. In this case as well, it is necessary to remove the hardened layer at the time of working the fastening surface. Processing can be performed easily.

After the main body 10 and the gear 20 having been subjected to the above-described fastening surface processing are cleaned, an adhesive is applied to the fastening surface of the main body 10 while the gear 20 is, for example, 150 gm.
° C, the gear portion 20 is fitted on the outer peripheral portion of the main body portion 10, and is allowed to cool to room temperature.
0, the gear portion 20 is fastened to the outer peripheral portion, and the adhesive is cured to form an adhesive layer 30 between the fastening surfaces.
And the gear portion 20 are firmly joined. And when the caulking piece is provided, it is further secured by caulking it to the other side, and then finishing is performed, whereby the dimensional accuracy as an integrated part is obtained. Will be improved.

In the manufacturing process shown in FIG. 2,
Although the example of heating the side of the gear portion 20 (so-called shrink fitting) has been described, in the present invention, it is necessary to fit the gear portion 20 in a state where the temperature of the gear portion 20 is higher than that of the main body portion to some extent.
For example, it is possible to cool the main body 10 by dry ice or liquid nitrogen (cold fitting), or to simultaneously heat the gear 20 and cool the main body 10.

The adhesive is applied to the main body 10 and the gear 20.
It is necessary to improve the joint strength between the two without causing deformation and destruction of the gear portion 20 by increasing the interference between the two, the hardening time is short, and a waiting time occurs in the production process. Because of this, the use of an anaerobic adhesive of the type that cures by expelling air is desirable.
In the above-described example of the manufacturing process, the example in which the adhesive is applied to the side of the main body 10 has been described. However, the adhesive may be applied to the fastening surface of the gear 20 or to both the main body 10 and the gear 20. It is also possible.

[0024]

The rolling element for a traction drive according to the first aspect of the present invention has a structure in which the main body and the gear are fastened by thermal expansion or contraction via an adhesive layer. By selecting the optimal combination of materials and heat treatment for the different main body and gear, the main body and gear with optimal strength and durability can be integrated, and the main body can be integrated with the adhesive layer. Sufficient joining strength can be obtained without increasing the interference between the gear part and the gear part, and the gear part can be prevented from being damaged or deformed, and a smooth meshing state without noise can be secured. This is an extremely excellent effect.

In an embodiment of the traction drive rolling element according to the present invention, the traction drive rolling element according to the second aspect is configured such that the interference between the main body and the gear portion is reduced to 0 with respect to the fastening surface dimension of the gear portion. % Or more, 0.153
% Or less, the necessary fastening force can be obtained without excessive tensile stress being applied to the gear portion on the outer peripheral portion, and the quality can be stabilized. In the traction drive rolling element according to No. 3, the interference is 0.03 to the fastening surface dimension of the gear portion.
Since it is further limited to the range of 7% or more and 0.100% or less, assembling workability is further improved and
The above effect can be made more reliable.

In the rolling element for traction drive according to the fourth aspect of the present invention, since the positioning means is provided on the fastening surface or at a position near the fastening surface, it is difficult to fit the rolling element.
The gear part can be quickly positioned at a predetermined position on the main body, thereby improving the dimensional accuracy of the rolling element and preventing the adhesive from being hardened or fastened during fitting. In the traction drive rolling element according to the fifth aspect, the caulking piece is formed in the vicinity of the fastening surface, and the caulking piece is caulked to the other side, so that the joining force can be further improved. Can transmit more power, and even if the joint strength by the fastening force and the adhesive force cannot withstand the transmission force, the gear part may come off the main body and damage other parts. An excellent effect that such a situation can be prevented beforehand is brought about.

In the traction drive rolling element according to claim 6, the structure according to the present invention is applied to an output disk for a toroidal-type continuously variable transmission.
Lightening and improving productivity of toroidal type continuously variable transmissions,
Furthermore, it greatly contributes to cost reduction.

In the method for manufacturing a rolling element for a traction drive according to claim 7 of the present invention, the main body and the gear are fastened in a state where predetermined processing and heat treatment have been performed in advance, and then predetermined processing is performed. By controlling the depth of the hardened layer to be optimal for each of the main body and the gear, it is possible to obtain a rolling element including the main body and the gear with optimal strength and durability, respectively. The dimensional accuracy as an integrated part can be improved by further performing a predetermined processing after the fastening. In the method for manufacturing a rolling element for traction drive according to claim 8, the heat quenching method for the gear portion is performed by a press quench method. Is applied, so heat treatment distortion is reduced, and less machining allowance is required for removing distortion. With bets can be reduced, since it is possible to equalize the cutting stock finishing results in excellent effect that can be made uniform effect layer depth by carburization.

[0029]

EXAMPLES The present invention will be described below more specifically based on examples.

First, a chromium molybdenum steel SCM420H specified in JIS G 4052 was used as a raw material.
The main body 10 shown in FIG.
The chrome steel SCr420H defined in G4052 was used as a raw material, and after the gear portion 20 shown in FIG. 1 was roughly machined, the main body portion 10 and the gear portion 20 were subjected to carburizing, quenching and tempering under different conditions.

Next, the outer diameter d of the fastening surface of the main body 10 is
And the inner diameter D of the fastening surface of the gear portion 20 is 150
mm, the fastening surface of the main body 10 is processed with an anaerobic adhesive (LOCTITE 1448 manufactured by Loctite Co., Ltd.).
After the application of 6), the gear portion 20 heated to 150 ° C. was fitted to the main body portion 10 to which the adhesive was applied, and was allowed to cool to room temperature and was fastened to the outer periphery of the main body portion 10. Then, after confirming the curing of the adhesive, the pull-out force of the fastening surface was examined.

FIG. 7 shows the drawing force ratio on the vertical axis when the drawing strength required for design is set to 1, and the room temperature (20 ° C.)
The interference (d−) calculated from the actually measured values of the outer diameter d (body portion) and the inner diameter D (gear portion) of the fastening surface in FIG.
D) as a percentage (100 × (d
-D) / D) is shown by rearranging the results on the horizontal axis, where the interference (d-D) is less than 0%, that is, in the fastening state having a gap, sufficient fastening strength and curing strength of the adhesive. Is not obtained, and the pull-out strength varies,
The desired strength may not be obtained, and the interference (d
If -D) exceeds 0.153% of the inner diameter D of the fastening surface, a sufficient gap cannot be obtained at the time of fitting, so that the adhesive hardens during the fastening and reaches a predetermined position. It has been confirmed that the pull-out strength varies greatly due to the sticking or the breakage of the gear portion 20 in some cases.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a structural example of an output disk as a traction drive rolling element according to the present invention.

FIG. 2 is a process chart showing an example of a method for manufacturing a traction drive rolling element according to the present invention.

FIG. 3 is a sectional view showing an embodiment in which a step portion is provided on a fastening surface as a positioning means.

FIG. 4 is a cross-sectional view showing an embodiment in which a collar is provided at an end of a fastening surface of a main body as positioning means.

FIGS. 5A and 5B are cross-sectional views showing an embodiment in which a caulking brim is provided at an end of a fastening surface of a main body as a caulking piece.

FIGS. 6 (a) and (b) are cross-sectional views showing an embodiment in which a caulking flange is provided as a caulking piece at an end of a fastening surface of a gear portion.

FIG. 7 is a graph showing the effect of interference (dD) on fastening surface inner diameter D on pull-out strength.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Output disc (rolling element for traction drive) 10 Main body part 11, 12 Rolling surface 13 Step part (positioning means) 14 Collar (positioning means) 15 Caulking collar (caulking piece) 20 Gear part 22 Step part (positioning means) 24 Collar (positioning means) 25 Caulking collar (clamping piece) 30 Adhesive layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) F16B 11/00 F16B 11/00 A // B21D 53/88 B21D 53/88 Z (72) Inventor Nakayama Tatsuomi 2 Takara-cho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture, Nissan Motor Co., Ltd. Nissan Motor Co., Ltd., 2 Takaracho, Kanagawa-ku, Tokyo (72) Inventor Hideki Usuki 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Nissan Motor Co., Ltd. F-term (reference) 3J023 EA01 GA01 3J051 AA03 BA03 BB02 BD02 BE09 EC02 ED16 ED20 FA02

Claims (8)

[Claims] 1. A traction drive rolling element comprising a power transmission gear portion fastened to an outer peripheral side of a main body portion having a rolling surface for transmitting power by a traction drive, wherein the gear portion is a main body portion. It is fitted to the main body in a state of higher temperature, is fastened in a state where the temperature difference between the two is substantially eliminated, and an adhesive layer is formed between the fastening surfaces of the main body and the gear portion. A rolling element for traction drive characterized by the following. 2. The rolling element for a traction drive according to claim 1, wherein the interference between the main body and the gear portion is in the range of 0 to 0.153% with respect to the fastening surface dimension of the gear portion. . 3. The traction drive according to claim 1, wherein the interference between the main body portion and the gear portion is in a range of 0.037 to 0.100% with respect to a fastening surface dimension of the gear portion. Rolling element. 4. The main body and the gear portion are axially positioned by a fastening surface formed between the main body portion and the gear portion or a positioning means formed at an end of the fastening surface. Item 4. The rolling element for traction drive according to any one of Items 3. 5. A caulking piece formed at one end of one of the fastening surfaces of the main body and the gear portion is caulked to the other of the main body portion and the gear portion. The rolling element for traction drive according to 1. 6. The rolling element for a traction drive according to claim 1, which is an output disk for a toroidal-type continuously variable transmission. 7. The method according to claim 1, wherein the main body and the gear are fastened in a state where predetermined processing and heat treatment have been performed in advance, and then predetermined processing is performed. A method for manufacturing a rolling element for a traction drive. 8. The method for manufacturing a traction drive rolling element according to claim 7, wherein the gear portion is heat-treated by a press quench method.