JP3229853B2 - Automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission, and more particularly, to a structure of a press part incorporated in an automatic transmission.

[0002]

2. Description of the Related Art In order to reduce the cost of an automatic transmission, a press product in which a plate material is formed into a predetermined sectional shape is used for many components. Typical examples of such pressed parts include a cancel plate that cancels out the effect of centrifugal oil pressure generated on the clutch hydraulic servo to improve the hydraulic controllability of the clutch as much as possible, and a retainer that supports the return spring of the clutch piston. An automatic transmission using parts is disclosed in Japanese Unexamined Patent Publication No. 2-29607.
No. 3 discloses this.

[0003]

When a component such as a cancel plate is formed by pressing a steel plate having a uniform thickness, the maximum stress acting on the pressed component must be adjusted according to the maximum stress.
It is necessary to determine the thickness and material. Thus, in the automatic transmission disclosed in the above publication, the thickness of the inner circumferential side of the cancel plate is increased to improve the strength. However, in such a case, the excess strength portion of the entire part increases, and the weight of the cancel plate or the like made of a pressed product increases by that much, which in turn increases the weight of the automatic transmission itself incorporating the same. Will be. In addition, if the thickness of each part is changed according to the applied stress, the productivity of press working will be impaired.

A component such as a cancel plate is normally supported in the axial direction by being brought into contact with a locking member of a shaft portion, and a maximum load is applied to an inner peripheral side serving as a contact support portion thereof. Therefore, it is necessary to secure the diameter of the part to some extent, preventing the reduction of the diameter of the shaft that supports it, increasing the outer diameter of the cancel plate, etc. by that much, and hindering the compactness of the automatic transmission. Become.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an automatic transmission that can be reduced in weight and size by incorporating parts that improve the strength of only necessary parts without impairing productivity by press working.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to an axially regulated state in which a locking portion provided on a peripheral surface of a shaft-like member is engaged to restrict the axial direction. In the automatic transmission provided with an annular plate member having a predetermined cross-sectional shape, the annular plate member has a reinforcing portion connected to an end portion engaged with the locking portion, and the reinforcing portion extends in the axial direction from the end portion. And a folded portion that is folded back from the portion and extends in the opposite direction to the innermost peripheral side of the annular plate member .

[0007] The peripheral surface of the shaft-shaped member is the outer peripheral portion of the rotating shaft, the locking portion is a snap ring fitted to the outer peripheral portion of the rotating shaft, and the folded portion of the annular plate member is
It may be configured to extend around the outer periphery of the snap ring so as to cover the snap ring.

[0008]

In the automatic transmission according to the present invention having the above-described configuration, the portion restricted by the locking portion has a stress acting on the annular plate member due to the action of the axial load and the moment. Where the maximum is,
Since the reinforcing portion is provided in this portion, the rigidity of the portion can be improved, and the portion having relatively low stress can be formed into a simple shape that does not require a special shape for thinning or maintaining rigidity. Because it is possible, it is effective in reducing the weight and size of the member. In addition, since the reinforcing portion is formed by folding the annular plate member, press working is easy, which is effective for reducing costs and improving strength.

According to the second aspect of the present invention, the expansion of the snap ring due to the centrifugal force caused by the rotation of the shaft can be prevented by the reinforcing portion of the annular plate member. It is not necessary to provide a separate stopper for cutting and raising the annular plate member, and the number of processing steps can be reduced also as a stopper for the snap ring.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partial cross-sectional view of an embodiment of an automatic transmission incorporating a cancel plate to which the present invention is applied, and FIG. 2 is a cross-sectional view showing the cancel plate. As shown in FIG. 1, the automatic transmission includes a clutch C1 which is engaged when one or three speeds are achieved on one side across a planetary gear train having a four forward speed / one reverse speed configuration, and a clutch C3 which is engaged during reverse. It is a horizontal type device in which a clutch C2 for engaging at the third speed or higher is arranged on the other side. In this device, the clutch C1 is required to have a high degree of controllability because it requires a so-called gripping operation for engaging while releasing the brake B1 at the time of a 4 → 3 downshift.
One hydraulic servo is provided with a centrifugal oil pressure canceling mechanism.

The clutch C1 comprises a frictional engagement element 3 for transmitting the rotation of the input shaft 1 to the sun gear shaft 2 and a hydraulic servo 4 for engaging and releasing the frictional engagement element.
Are supported by a drum 41 also serving as a servo piston of an adjacent clutch C3 and a hub 21 fixed to the sun gear shaft 2. In the hydraulic servo 4 having the drum 41 as a cylinder, a piston 42 is built in the input shaft 1 and the drum 41 to support the inner and outer circumferences.
A cancel plate 5 is provided to support the inner and outer circumferences. The cancel plate 5 also serves as a spring seat on the other end side of the return spring 6 whose one end is supported by the piston 42 via the spring seat 61.

More specifically, as shown in an enlarged manner in FIG. 2, the cancel plate 5 as an annular plate member is a locking portion fitted to the outer peripheral portion 10 of the input shaft 1 constituting a shaft-shaped member. The plate has a predetermined cross-sectional shape that is axially regulated by engaging with the snap ring 7 and receives an axial load by hydraulic pressure. In this example, cancel plate 5
An annular portion 51 on the outer peripheral side that forms a seal portion, a cup-shaped portion 52 on the inner peripheral side that defines a storage space for the return spring 6, and an annular bent portion 53 formed by projecting them along the shape of a piston. A seal ring 54, which has a substantially uniform cross-sectional shape and has a substantially uniform cross-sectional shape, and which seals a sliding portion with the piston 42 on the outer peripheral side 51, is attached by baking or the like.

According to the present invention, the cancel plate 5
On its innermost peripheral side, an end 55 engaging with the snap ring 7 is provided .
It has a reinforcing portion 55 connected to a. The reinforcing portion 55 is provided at the end 5
A portion 55b extending in the axial direction from 5a, and a folded portion 55 folded from the portion 55b and extending in the reverse direction
c. Then, due to this shape, the folded portion 55c of the cancel plate 5 extends around the snap ring 7 so as to cover the snap ring 7.

In the clutch having such a configuration, FIG.
As shown in FIG. 5, the oil supplied between the drum 41 and the piston 42 from the in-shaft oil passage 12 connected to the line pressure oil passage 11 formed in the shaft of the input shaft 1 And the lubricating oil passage 13 formed in the shaft of the input shaft 1 against the centrifugal oil pressure generated by the rotation of the piston 42.
The oil supplied between the piston 42 and the cancel plate 5 from the in-shaft oil passage 14
And the centrifugal oil pressure generated by the rotation of the cancel plate 5 serves to cancel the load due to both oil pressures in the axial direction.

In order to cancel such centrifugal oil pressure,
An axial load is applied to the cancel plate 5 by hydraulic pressure. The load is proportional to the distance from the rotation center and proportional to the square of the rotational angular velocity due to the characteristics of the centrifugal hydraulic pressure. A large stress is applied to the innermost peripheral portion supporting the moment. On the other hand, according to the present invention, since the above-described reinforcing portion 55 is formed on the innermost peripheral side of the cancel plate 2, sufficient rigidity and strength against stress can be obtained.

Further, in this example, since the cancel plate 5 also serves as a spring seat as described above, a load due to the compression of the return spring 6 is applied in addition to the above load during the piston stroke.
Therefore, the reinforcing portion 55 functions effectively also for this.

On the other hand, a centrifugal force is applied to the snap ring 7 by the rotation of the input shaft 1, which causes a force to expand the snap ring 7. According to the present invention, the folded portion 55 c of the reinforcing portion 55 of the cancel plate 5 is used. Extends around the outer periphery of the snap ring 7 so as to encompass the snap ring 7, the expansion of the snap ring 7 is prevented by contact with the folded portion 55c, and the snap ring 7 is prevented from coming off.

Looking further at the axial positional relationship between the components of the automatic transmission, the distance between the return spring seat 61 of the piston 42 and the cup-shaped bottom of the cancel plate 5 is naturally determined by the compression stroke of the return spring 6. In contrast, the reinforcing portion 55 of the cancel plate 5 extends from the cup-shaped bottom in the direction of the space in which the return spring 6 is provided, so that the reinforcing portion 55 is provided. An increase in the axial dimension of the transmission is completely avoided.

In short, according to the above embodiment, the portion regulated by the snap ring 7 is where the stress acting on the cancel plate 5 becomes maximum due to the action of the axial load and the moment. Since the reinforcing portion 55 is provided in this portion, the rigidity of the portion can be improved, and the portion having relatively low stress has a simple shape that does not require a special shape for thinning or maintaining rigidity. This is effective in reducing the weight and size of the member. Further, since the reinforcing portion 55 is formed by folding the cancel plate 5, press working is easy,
It is effective for both cost reduction and strength improvement. Next, the expansion of the snap ring 7 due to the centrifugal force caused by the rotation of the shaft can be prevented by the reinforcing portion 55 of the cancel plate 5, so that the annular plate member is separately prevented from coming off by raising or lowering the annular plate member as in the related art. It is not necessary to perform the process, and the number of processing steps can be reduced by also preventing the snap ring 7 from coming off.

In this embodiment, since the annular plate member is formed as a cancel plate, the inner peripheral diameter is made substantially equal to the inner peripheral diameter of the piston 42 because of the necessity of balancing centrifugal oil pressure, and the outer peripheral diameter is also reduced. Although it is substantially equal to the outer diameter of the piston 42, the annular plate member alone looks like
If it is a component in which the reduction of the inner diameter is restricted by the restriction on strength and the reduction of the outer diameter is hindered accordingly, only the improvement in strength due to the formation of the reinforcing portion according to the present invention. By reducing the inner diameter and the outer diameter accordingly, it is possible to help reduce the radial size of the transmission case in which the inner diameter is reduced.

Although the present invention has been described in detail based on one embodiment in which the present invention is applied to a cancel plate, the present invention is not limited to this, and various components may be included within the scope described in the claims. It is applicable to.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of an automatic transmission in which the present invention is applied to a cancel plate.

FIG. 2 is a partial sectional view showing the cancel plate taken out.

[Explanation of symbols]

Reference Signs List 1 input shaft (rotating shaft) 5 cancel plate (annular plate member) 7 snap ring (locking portion) 10 outer peripheral portion (peripheral surface of shaft-shaped member) 55 reinforcing portion 55a end portion 55b portion extending in the axial direction 55c folded back part

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoru Kasuya 10 Takane, Fujii-machi, Anjo, Aichi Prefecture Inside Aisin AW Co., Ltd. Inside (72) Inventor Masafumi Kinoshita 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (56) References JP-A-2-296073 (JP, A) JP-A-4-64722 (JP, A ) Practical application Hei 2-117410 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16D 25/00-25/12 F16D 13/00-13/60 F16B 21/18 F16H 57 / 02

Claims (2)

(57) [Claims] 1. An automatic transmission comprising an annular plate member having a predetermined cross-sectional shape which is axially regulated by being engaged with a locking portion provided on a peripheral surface of a shaft-shaped member and receives an axial load on a plate surface. The annular plate member has a reinforcing portion that is continuous with an end portion that engages with the locking portion. The reinforcing portion has a portion that extends in the axial direction from the end portion, and a direction that is folded back from the portion and goes backward. An automatic transmission having a folded portion extending to the innermost peripheral side of the annular plate member . 2. The peripheral surface of the shaft-like member is an outer peripheral portion of a rotating shaft, the locking portion is a snap ring fitted to the outer peripheral portion of the rotating shaft, and the folded portion of the annular plate member is The automatic transmission according to claim 1, wherein the automatic transmission extends around an outer circumference of the snap ring to encompass the snap ring.