JP2788306B2 - Friction fastening element - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a friction fastening element applied to a power train of an automatic transmission as a multi-plate clutch, a multi-plate brake, or the like.

(Prior Art) In recent years, press-molded pistons and clutch drums of a multi-plate clutch have been frequently used for the purpose of weight reduction.

As the former formed by pressing the piston, those described in JP-A-57-200729 and JP-A-61-175327 are known, and the latter is formed by pressing the clutch drum. Are known from JP-A-59-140925. These multiple disc clutches are provided with a drift-on ball valve facing the piston oil chamber in order to release pressurized hydraulic oil in the piston oil chamber when the clutch is released.

However, in the case where the former piston is press-formed, on the clutch drum side which is not a press-formed product, and in the case where the latter clutch drum is press-formed, on the piston side which is not a press-formed product, Machining a ball hole having a cylindrical surface and a conical surface with high precision,
Since the valve hole is provided in the ball hole, a large number of processing steps are required, and the ball hole is very expensive.

In order to solve the above problem, for example,
As described in JP-A-59-175631, etc., a ball cylinder having a ball hole is made in advance by performing precision control, and the ball-cylinder is pressed into a ball-cylinder press-fitting hole formed in a piston or a drum to thereby obtain a drift-on ball. Techniques for providing a valve have been proposed.

(Problems to be Solved by the Invention) However, in the above-mentioned prior art, a ball cylinder is prepared as a separate part, and the ball cylinder is pressed into a ball cylinder press-fitting hole formed in a piston or a drum, so that a drift-on ball valve is provided. Since the number of parts constituting the drift-on ball valve increases, a lot of man-hours are required for manufacturing the ball cylinder and opening the ball cylinder press-fitting hole, and the ball cylinder press-fitting work is required. Is disadvantageous in terms of cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a friction fastening element having a drift-on ball valve at extremely low cost.

(Means for Solving the Problems) In order to solve the above problems, in the friction fastening element of the present invention, a drift-on ball valve is provided on a press-formed product side of a drum and a piston, and at least a part of a ball cylinder is formed by a press. The means was formed integrally with the molded article.

That is, a drum and a hub that are respectively integrated with the drive side and driven side power transmission members, a drive plate and a driven plate that is fixed to the drum and the hub in a circumferential direction and that is movable in the axial direction, At least one of the drum and the piston is press-formed in a friction fastening element including a piston for applying a frictional fastening force to a plate and a drift-on ball valve provided to face a piston oil chamber for extracting hydraulic oil when released. The drift-on ball valve is characterized in that at least a part of the ball cylinder is formed by a part of the press-formed drum or piston.

(Operation) When press-forming at least one of a drum and a piston, which are press-formed products, at least a part of the ball cylinder of the drift-on ball valve is formed by simultaneous molding, and it is necessary to manufacture a ball cylinder press-in hole and a ball cylinder. do not do.

When assembling the drift-on ball valve, prepare a valve ball and a retainer for retaining the valve ball, and insert the valve ball into the ball cylinder part formed on the drum or piston which is a press-formed product. By simply attaching a retainer or the like, the assembly of the drift-on ball valve is completed, and the work of press-fitting the ball cylinder is not required.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

 First, the configuration will be described.

FIG. 1 is a sectional view showing a multi-plate clutch (an example of a frictional fastening element) according to a first embodiment, in which a clutch drum 1 fixed to a driving power transmission member (not shown) and a driven power transmission member (not shown). , A drive plate 3 and a driven plate 4 alternately arranged with each other and spline-connected to the clutch drum 1 and the clutch hub 2 so as to be circumferentially fixed and movable in the axial direction. And a press-formed piston 5 for applying a frictional fastening force to the driven plate 4, and the press-formed piston 5 for completely removing the pressurized hydraulic oil in the piston oil chamber 6 when released.
And a drift-on ball valve 7 provided at an outer diameter position of the vehicle.

In FIG. 1, 8 is a snap ring, 9 is a retaining plate, 10 is a dish plate, 11 is a return spring, 12 is a spring retainer, 13 and 14 are piston seals, and 15 is a clutch oil hole.

In order to provide the piston seals 13 and 14 on the press-formed piston 5, an outer retainer ring 51 and an inner retainer ring 52 are provided on the press-formed piston 5 by spot welding or the like.

The drift-on ball valve 7 is provided with a valve ball 71 inserted into a ball cylinder portion 5a integrally formed by deep drawing at the time of press forming of the press forming piston 5.
And a ball retainer 72 fitted to the locking step 5b formed at the ball hole entrance.

 Next, the operation will be described.

(A) At the time of assembling the drift-on ball valve First, when press-forming the press-formed piston 5, the entire ball cylinder portion 5a of the drift-on ball valve 7 is integrally formed by deep drawing or the like, and the ball hole inlet is formed. A locking step 5b is formed in the portion.

That is, unlike the prior art, the ball cylinder press-fitting hole is formed by press machining piston 5 without the need to form the ball cylinder press-fitting hole by precision machining or to manufacture a separate ball cylinder. It is formed.

When assembling the drift-on ball valve 7, a valve ball 71 and a ball retainer 72 for retaining the valve ball 71 are prepared, and the valve ball is mounted on the ball cylinder portion 5a formed on the press-formed piston 5. By just inserting the ball retainer 71 and fitting the ball retainer 72 to the locking step 5b, the assembly of the drift-on ball valve 7 is completed.

That is, as in the conventional ball cylinder press-fitting method,
The assembly of the drift-on ball valve 7 can be performed without the need to press-fit the ball cylinder into the ball cylinder press-fitting hole by a press-fitting machine.

(B) At the time of clutch operation When the multi-plate clutch is engaged, pressurized hydraulic oil is introduced into the piston oil chamber 6 from the clutch oil hole 15 and the press-formed piston 5 moves to the left in FIG. The stroke is performed by applying to the drive plate 3 and the driven plate 4 a fastening force obtained by multiplying the pressure of the piston oil chamber 6 by the piston pressure receiving area. Then, by this clutch engagement operation, torque is transmitted from the clutch drum 1 to the clutch hub 2 via the drive plate 3 and the driven plate 4.

In this clutch engagement operation, the valve ball 71 is actuated by the pressurized hydraulic oil supplied to the piston oil chamber 6.
, And closes the drift-on ball valve 7 with a pressing force corresponding to the oil pressure.

On the other hand, when the multi-plate clutch is released, the pressurized hydraulic oil in the piston oil chamber 6 is drained from the clutch oil hole 15, and the press-formed piston 5 is stroked rightward in FIG. Plate 3
And by releasing the clutch engagement force applied to the driven plate 4.

During this clutch disengagement operation, the valve ball 71 moves in the direction toward the piston oil chamber 6 (rightward in FIG. 1) as the oil pressure in the piston oil chamber 6 decreases, and the valve ball 71 is prevented from falling off by the ball retainer 72. While the drift-on ball valve 7 is released, the inside of the case from the drift-on ball valve 7 is introduced to promote the hydraulic oil drain from the clutch oil hole 15.

As described above, in the multiple disc clutch of the first embodiment, the drift-on ball valve 7 is provided on the press-formed piston 5 side, and the ball cylinder portion 5a is formed integrally with the press-formed product. Therefore, a multi-plate clutch having the drift-on ball valve 7 can be provided at extremely low cost.

That is, it is not necessary to machine a ball hole having a cylindrical surface and a conical surface with high precision as in the conventional technology of the ball hole machining type, and it is not necessary to machine the ball cylinder as in the conventional technology of the ball cylinder press-fit type. It is not necessary to manufacture, to open the ball cylinder press-in hole, or to perform the ball cylinder press-in operation.

Next, the multi-plate clutch according to the second embodiment shown in FIG. 2 will be described.

The multi-plate clutch of the second embodiment is an example in which the ball cylinder is formed integrally with the press-formed piston 5 in contrast to the first embodiment in which the ball cylinder is entirely formed by the ball cylinder portion 5a. This is an example in which a portion 5a 'and an outer retainer ring 51 are formed together.

In the first embodiment, the valve ball 71 is prevented from falling off by the ball retainer 72, whereas the stopper ball 73 spot-welded to the press-formed piston 5 is used. Differently.

The operation and effect are the same as in the first embodiment, but in the second embodiment, a part of the ball cylinder is obtained by the outer retainer plate 51. The position can be arranged at the outermost diameter position of the piston adjacent to the piston seal 13. As a result, it is difficult to form a vortex around the ball hole, and the effect that the hydraulic oil rejection characteristic of the drift-on ball valve 7 is stabilized can be obtained. Can be

As described above, the embodiments have been described based on the drawings. However, the specific configuration is not limited to the embodiments, and even if there is a design change or the like without departing from the gist of the present invention, it is included in the present invention. .

For example, in the embodiment, the example of the multi-plate clutch is shown, but the present invention can be similarly applied to the case of a multi-plate clutch.

Further, in the embodiment, the example in which the drift-on ball valve 7 of the piston is provided is shown, but the drift-on ball valve 7 may be provided on the clutch drum side facing the piston oil chamber 6.

(Effects of the Invention) As described above, in the friction fastening element of the present invention, the drift-on ball valve is provided on the press-formed product side of the drum and the piston, and at least a part of the ball cylinder is press-formed. Since the means is formed integrally with the product, it is possible to obtain an effect that a friction fastening element having a drift-on ball valve can be provided at extremely low cost.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a multi-plate clutch (friction fastening element) according to a first embodiment of the present invention, and FIG. 2 is a sectional view showing a multi-plate clutch according to a second embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Clutch drum (drum) 2 ... Clutch hub (hub) 3 ... Drive plate 4 ... Driven plate 5 ... Press forming piston 5a, 5a '... Ball cylinder part 6 ... Piston oil chamber 7 ... Drift-on ball valve 71 …… Valve ball

Claims (1)

(57) [Claims] 1. A drum and a hub, which are respectively integrated with a power transmission member on a driving side and a driven side, a drive plate and a driven plate provided on the drum and the hub so as to be circumferentially fixed and axially movable, and In a friction fastening element including a piston that applies a frictional fastening force to the plate and the driven plate, and a drift-on ball valve that faces the piston oil chamber to release hydraulic oil when released, at least one of the drum and the piston is provided. A friction-tightened element, which is a press-formed product, wherein at least a part of a ball cylinder of the drift-on ball valve is formed by a part of a drum or a piston formed by the press-forming.