JP2001208106A - Ratchet type one way clutch and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability of a ratchet-type one way clutch with an aluminum outer ring having a function of locking up the clutch in one direction or both directions in order to solve problems such as increase in number of parts, complication, weight increase and cost increase. SOLUTION: The ratchet-type one way clutch comprising an outer ring having a pocket at its inner periphery, an inner ring arranged coaxially with the outer ring and having notches at its outer periphery, ratchets contained in the pocket for transmitting torque between the inner ring and the outer ring by fitting into the notches of the inner ring, and an elastic body for urging the ratchets to the inner ring is characterized in that the outer ring is made of aluminum and hardening treatment is provided for the inner periphery side surface of the outer ring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a one-way clutch which is used for a transmission of an automobile, an agricultural machine, a construction machine, an industrial machine, etc., in particular, an automatic transmission of a vehicle, etc., and which functions as a backstop. More specifically, the present invention relates to a ratchet type one-way clutch using a ratchet (claw) for a lock mechanism and a method of manufacturing the same.

[0002]

2. Description of the Related Art Generally, a one-way clutch used for an automatic transmission has an outer ring and an inner ring which rotate relatively to each other, and a sprag or a roller for transmitting torque between the outer ring and the inner ring is provided on a raceway surface of the outer ring or the inner ring. By engaging with the provided cam surface, the rotational torque is transmitted in only one direction. In addition, it is configured to idle in the reverse direction.

[0003] Among such one-way clutches, there is a ratchet type one-way clutch using a ratchet as a torque transmitting member for transmitting torque between an outer ring and an inner ring. The ratchet type one-way clutch includes an outer race having a pocket on the inner periphery, an inner race arranged coaxially with the outer race and having a notch on the outer periphery, and a notch stored in the pocket and fitted to a notch of the inner race to lock the one-way clutch to the inner race. And an elastic member for urging the claw toward the inner ring.

In the ratchet type one-way clutch having the above structure, when the one-way clutch rotates in one direction, the pawl slides freely with respect to the outer periphery of the inner ring, so that the outer ring and the inner ring relatively idle. Next, when the one-way clutch tries to rotate in the other direction, the pawl engages with the notch, and the one-way clutch is locked.

[0005]

Normally, the outer ring of a ratchet type one-way clutch is made of aluminum. However, since the claws repeatedly swing in a pocket provided in the outer ring, the outer ring is not necessarily provided in terms of durability. I was not satisfied. Accordingly, an object of the present invention is to improve the durability of a ratchet type one-way clutch in which the outer ring is made of aluminum.

[0006]

In order to achieve the above object, a ratchet type one-way clutch according to the present invention comprises: an outer ring having a pocket on the inner periphery; an inner ring disposed coaxially with the outer ring and having a notch on the outer periphery; A ratchet-type one-way clutch comprising a pawl housed in the pocket, fitted to a notch of the inner race and transmitting torque between the inner race and the outer race, and an elastic body for urging the pawl toward the inner race. Wherein the outer race is made of aluminum, and a hardening treatment is performed on an inner peripheral surface of the outer race.

In order to achieve the above object, a method of manufacturing a ratchet type one-way clutch according to the present invention comprises: an outer ring having a pocket on an inner periphery; an inner ring disposed coaxially with the outer ring and having a notch on an outer periphery; A method of manufacturing a ratchet-type one-way clutch including a pawl housed in the pocket, fitted to a notch of the inner ring and transmitting torque between the inner ring and the outer ring, and an elastic body for urging the pawl toward the inner ring. Wherein the method includes a step of forming the outer race from aluminum by die casting and a step of performing a hardening treatment on an inner peripheral surface of the outer race.

[0008]

According to the ratchet type one-way clutch according to the first aspect, since the inner surface of the outer race formed of aluminum is subjected to the hardening treatment, the durability is improved.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a ratchet type one-way clutch, which includes a step of molding an outer race made of aluminum and a step of performing a hardening treatment on an inner peripheral surface of the outer race. A ratchet-type one-way clutch with improved properties can be manufactured.

[0010]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In the drawings, the same parts are denoted by the same reference numerals. FIG. 1 is a full front view of a ratchet type one-way clutch to which each embodiment of the present invention is applied.
FIG. 2 is a sectional view taken along line AA of FIG.

The ratchet type one-way clutch 1 is used in a stator of a torque converter for an automatic transmission used in an automobile or the like.
No. 47,245. As shown in FIG.
The annular outer ring 30 is formed from aluminum by die casting, and is formed integrally with the stator blades 33. On the inner peripheral side of the outer ring 30, a pocket 31 opened to the inner ring 20 side for accommodating the claw 40, and provided at the back of the pocket 31. And a spring pocket 32 for accommodating the spring 50. In FIG. 1, three pawls 40, pockets 31, and spring pockets 32 are provided at equal intervals in the circumferential direction. Can be reduced. However, it is preferable to provide them at equal pitches in the circumferential direction. FIG.
Indicates that the ratchet type one-way clutch is in the locked state. Further, the spring 50 is preferably a coil spring, but it goes without saying that other forms of spring such as a wave spring can also be used.

On the other hand, the inner race 20 has a notch 22 on the outer peripheral side for fitting with the pawl 40, and a spline 21 on the inner peripheral side for fitting with a shaft (not shown). The notch 22 extends in the axial direction, and its axial length corresponds to the axial width of the claw 40. As shown in FIG. 1, a notch 22 is formed by grinding an outer peripheral portion of the cylindrical member. Therefore, the notch 22 and the step portion 24 are arranged on the outer circumference of the inner ring 20 at equal intervals in the circumferential direction. Needless to say, the number of the notches 22 and the number of the step portions 24 can be arbitrarily set according to the number of the claws 40 and the like.

As shown in FIG. 2, a bearing member 60 is interposed between the outer race 30 and the inner race 20 at one end in the axial direction, and the bearing member 60 is prevented from coming off in the axial direction by the snap ring 80. I have. Both ends in the axial direction of the ratchet type one-way clutch 1 are rotatably supported by needle bearings 70.

In the ratchet type one-way clutch 1 configured as described above, the outer ring 30 and each member disposed on the outer ring 30 can rotate clockwise with respect to the inner ring in FIG. The function that the counterclockwise rotation cannot be performed in FIG. That is, the one-way clutch can be idle in the right direction but locked in the left direction.

As shown in FIG. 5, the pawl 40 of the ratchet type one-way clutch 1 which operates as described above
0 pocket 31 from the axially deep wall of pocket 31
The protrusion 34 protrudes inward in the axial direction and the protrusion 93 protrudes inward in the axial direction of the pocket 31 from the end face in the axial direction of the bearing member 90. For this reason, the pawl 40 swings around an axis connecting the projection 34 and the projection 93, and is freely displaceable between a position where the claw 40 is fitted to the notch 22 and a position where the claw 40 slides on the outer peripheral surface of the inner ring 20. is there.
A first to third embodiments of the present invention will be described based on the ratchet type one-way clutch described above.

(First Embodiment) FIGS. 3 and 4 are partial cross-sectional views showing details of the outer race 30 of the first embodiment. A hardening treatment was performed on the inner peripheral surface of the outer ring 30 to form a hardened layer 103. In FIG. 3, the hardening process is performed on the entire inner peripheral surface of the outer ring 30. However, for example, as illustrated in FIG. 4, the hardening process may be performed only on the surface inside the pocket 31. By performing the hardening process, it is possible to suppress dents and abrasion due to the pressure received from the claws 40 at the time of meshing or repeated swinging. Further, even if the claw 40 vibrates or swings in the pocket 31, wear of the inner wall of the pocket 31 can be suppressed to a minimum. Thereby, the durability of the ratchet type one-way clutch is improved, and the life is extended.

(Second Embodiment) FIG. 5 is a sectional view of a main part of a ratchet type one-way clutch 1 showing a second embodiment of the present invention. As described above, the outer race 30 is formed from aluminum by die casting. At this time, it is necessary to provide the inclined surface 110 having an inclination angle (draft angle) α with respect to the joint of the molds due to the die cutting. The inclined surface 110 can be removed by a shaving process or the like in a later step. However, this process requires a lot of trouble and cost because the shape of the pocket 31 is slightly complicated. For this reason, the joint surface 111 of the claw 40 is given an inclination angle α in advance according to the draft angle α of the outer ring 30. Therefore, according to the present embodiment, it is possible to save the labor of processing and to expect the effect of cost reduction. The joining surfaces 114 and 115 of the bearing member 90 held by the inner ring 20 and the snap ring 102 need to be cut due to dimensional accuracy, so that the inclination can be removed at this time.
In addition, since the joint surface with the inner ring 20 and the bearing member 90 is a simple shape, it does not take much trouble.

(Third Embodiment) FIG. 6 is a partial sectional view showing details of an outer race of a third embodiment. In addition to the above-described die casting process, coining or sizing is performed on the inner peripheral surface of the pocket 31 to improve dimensional accuracy and cause work hardening (strain hardening). For example, in this embodiment, the nail 4
0 pressure receiving surface 104 of the pocket 31 against which the rear portion hits under pressure
By processing in this manner, the positioning accuracy of the nail 40 is improved,
The load can be evenly received. As used herein, “work hardening” refers to an increase in yield point (a stress that causes plastic deformation to some extent) due to plastic deformation.

[0019]

As described above, the present invention has the following effects. Since the hardening treatment has been performed on the surface of the pocket where the nail hits, the durability of the ratchet type one-way clutch using the aluminum outer ring can be improved.

[Brief description of the drawings]

FIG. 1 is a front view of a ratchet type one-way clutch to which each embodiment of the present invention is applied.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a partial sectional view showing details of an outer race of the first embodiment.

FIG. 4 is a partial sectional view showing details of an outer race of the first embodiment.

FIG. 5 is a sectional view of a main part of a ratchet type one-way clutch 1 showing a second embodiment of the present invention.

FIG. 6 is a partial sectional view showing details of an outer race of a third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Ratchet type one-way clutch 20 ... Inner ring 22 ... Notch 30 ... Outer ring 31 ... Pocket 40 ... Claw 50 ... Spring 103, 104 ... Hardened surface

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuhiko Muramatsu 2345 Aino, Fukuroi-shi, Shizuoka NSC Warner Co., Ltd.

Claims (8)

[Claims] 1. An outer ring having a pocket on an inner periphery, an inner ring arranged coaxially with the outer ring and having a notch on an outer periphery, and an inner ring housed in the pocket and fitted to a notch of the inner ring to form the inner ring and the outer ring. A ratchet type one-way clutch having a claw for transmitting torque between the claw and an elastic body for urging the claw toward the inner ring, wherein the outer ring is made of aluminum, and a hardening treatment is performed on an inner peripheral surface of the outer ring. A ratchet-type one-way clutch characterized by the following. 2. The method according to claim 1, wherein the outer ring is formed by die-casting, and an inclined angle corresponding to a draft angle generated by the die-casting of the outer ring is formed on a joint surface of the claw with the pocket. The ratchet-type one-way clutch according to claim 1. 3. The ratchet type one-way clutch according to claim 1, wherein the hardening process is a shot peening or a hard alumite process. 4. The ratchet-type one-way clutch according to claim 1, wherein a coining or sizing process is performed on a pressure receiving surface of the pocket where the claw contacts. 5. An outer race having a pocket on the inner periphery, an inner race arranged coaxially with the outer race and having a notch on the outer periphery, and an inner race housed in the pocket and fitted to a notch of the inner race, and the inner race and the outer race. A method of manufacturing a ratchet-type one-way clutch having a claw for transmitting torque between the claw and an elastic body for urging the claw toward the inner ring, a step of molding the outer ring from aluminum by die casting; and an inner periphery of the outer ring. Performing a hardening treatment on the surface on the side of the ratchet. 6. The method according to claim 5, wherein an inclined angle corresponding to a draft angle generated by die-casting the outer race is formed on a surface of the claw that is joined to the pocket. . 7. The method according to claim 5, wherein the hardening treatment is shot peening or hard alumite processing. 8. The manufacturing method according to claim 5, wherein said method includes a step of performing coining or sizing processing on a pressure receiving surface of said pocket hitting said claw.