JP2547526Y2 - Band brake device for 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 a band brake device for an automatic transmission that brakes and releases a clutch clutch for shifting incorporated in the automatic transmission.

[0002]

2. Description of the Related Art As a conventional technique, there is one having a structure shown in FIG. In FIG. 2, reference numeral 1 denotes a case of an automatic transmission, which is formed of an aluminum alloy material. Reference numeral 2 denotes a shift clutch drum accommodated in the case 1, and a brake band 3 is suspended around the outer periphery of the clutch drum 2. The brake band 3 has its opposite ends separated and opposed at the upper part of the clutch drum 2, and each end is bent outward in the radial direction to form locking portions 4, 5 facing each other in the left-right direction. An anchor end pin 6 screwed into the case 1 is brought into contact with the left engaging portion 4 from the left, and a stem 11 of the hydraulic servo mechanism 10 is brought into contact with the right engaging portion 5 from the right. Let it.

The hydraulic servo mechanism 10 forms a housing chamber 12 having a left side closed and a right side open at the right portion of the case 1, and a plastic retainer 13 having a right side closed in the housing chamber 12. Fix together. The retainer 13
Is formed with a step having an inner periphery with a large diameter on the left, a small diameter on the middle and an intermediate diameter on the right. A first piston 15 and a second piston 16 integrally connected to the left and middle portions of the retainer 13 by a plastic material.
Are slidably fitted, and a plastic third piston 17 is slidably fitted to the right part of the retainer 13, and the first to third pistons 15 to 17 are used to move the inside of the retainer 13. Divided into left and right first to fourth oil chambers 18 to
21 are formed.

The above-described stem 11 is attached to the first to third pistons 15 to 17. The stem 11 is formed as a stepped shaft in which the right half has a small diameter and the left half has a large diameter, and the right half is slidably penetrated through the axial centers of the first and second pistons 15 and 16. The right end is fixed to the third piston 17, the left half is slidably penetrated into the case 1, and the left end protrudes leftward from the case 1 to lock the right part of the brake band 3 described above. Contact the part 5. The first piston 15 and the second piston 16 are moved rightward by a first return spring 22 provided in the first oil chamber 18, and the third piston 17 is moved rightward by a second return spring 23 provided in the third oil chamber 20. The first and second return springs 22 and 23 are pressed and urged by the reaction force of the first and second return springs 22 and 23.
1 to the right, that is, in the direction in which the brake band 3 is released.

The first oil chamber 18, the second oil chamber 19, and the fourth oil chamber 21 are control oil passages (not shown) for generating hydraulic pressure at the third speed, the second speed, and the fourth speed of the automatic transmission. , And the third oil chamber 20 is connected to a drain oil passage (not shown). When adjusting the initial gap of the brake band 3 with respect to the clutch drum 2, that is, the shift point, the anchor end pin 6 is screwed until the brake band 3 tightens the clutch drum 2 with the oil pressure in the control oil passage released. From this state, adjustment is made by loosening the anchor end pin 6 by a predetermined amount.

[0006]

In the prior art described above, when adjusting the initial clearance of the brake band 3, when the anchor end pin 6 is screwed in until the brake band 3 tightens the clutch drum 2, the load due to this screwing is reduced to the right. Acting on the stem 11 via the locking portion 5, a large load is applied to the first to third pistons 15 to 17 and the retainer 13, and there is a disadvantage that they are damaged. In particular, when the first to third pistons 15 to 17 and the retainer 13 are formed of a plastic material in order to reduce the weight and cost, the above-described drawbacks become significant. An object of the present invention is to provide a new band brake device for an automatic transmission that has solved the above-mentioned disadvantages.

[0007]

According to the present invention, in order to achieve the above object, a brake band is suspended around a clutch drum provided in a case, and both ends of the brake band project radially outward from each other. A pair of locking parts facing each other are provided, and an anchor end pin screw-fitted to the case is brought into contact with one of the locking parts from the outside in the tangential direction, and the stem of the hydraulic servo mechanism is tangentially outward on the other locking part. The automatic transmission band brake device is configured to move the other locking portion in the tangential direction by operating the stem in the tangential direction. When the brake band is not operated, the other locking portion is configured to abut from the outside in the tangential direction.

[0008]

Since the present invention has the above structure, when the anchor end pin is screwed in a state where the hydraulic pressure acting on the hydraulic servo mechanism is released, one of the locking portions of the brake band moves in the direction of the other locking portion. Then, the other locking portion collides with a stopper formed on the case and is prevented from retreating. When the anchor end pin is further screwed in this state, the distance between the one locking portion and the other locking portion becomes small, the brake band changes to a small diameter, and the clutch drum is tightened. When the brake band tightens the clutch drum, the screwing load of the anchor end pin suddenly becomes excessive, so that further screwing is not possible. Next, when the anchor end pin is loosened by a predetermined amount,
The brake band returns to a large diameter to release the tightening of the clutch drum, thereby setting the initial gap of the brake band with respect to the clutch drum.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of the present invention. In FIG. 1, the same reference numerals as in FIG. 2 have the same structure as in FIG. In FIG. 1, reference numeral 3 denotes a brake band 3 which hangs around the outer periphery of the clutch drum 2. The two ends of the brake band 3 are separated from each other at the upper part of the clutch drum 2, and each end is radially outward (upward). ) To form locking portions 3a, 3b facing each other in the left-right direction. An anchor end pin 6 screw-fitted to the case 1 is brought into contact with the left locking portion 3a from the left as in the conventional case. The right locking portion 3b is made to protrude more upward than the left locking portion 3a, and a stem 11 of the hydraulic servo mechanism 10 is provided at a base (lower portion) of the locking portion 3b.
Face from the right.

A stopper 1a projecting downward is formed on the upper right part of the case 1, and a left surface 1b of the stopper 1a is formed.
Is brought into contact with the distal end (upper portion) of the locking portion 3b from the right. The left surface 1b of the stopper 1a is 1 m from the left end 11a of the stem 11 when the stopper 1a moves rightward (at the beginning of operation).
m to 2 mm to the left. The effective stroke of the stem 11 in the left-right direction is about 8 mm. The operating characteristics of the brake band 3 by the anchor end pin 6 are set as follows. That is, when the right locking portion 3b of the brake band 3 comes into contact with the stopper 1a, the brake band 3 releases the tightening of the clutch drum 2, and the stem 11 causes the right locking portion 3b to move to the stopper 1a. The brake band 3 is set so as to tighten the clutch drum 2 when the brake band 3 moves leftward from the position, that is, about 3 mm in the direction of the left locking portion 3a.

According to the above embodiment, the first oil chamber 18, the second oil chamber 18,
The control oil is appropriately supplied to the oil chamber 19 and the fourth oil chamber 21 so that the stem 11
Is controlled to move in the left and right direction, and the movement of the stem 11 causes the right locking portion 3b to move in the left and right direction, and the brake band 3 tightens or releases the clutch drum 2 to perform a predetermined shift operation.

When adjusting the initial gap of the brake band 3 with respect to the clutch drum 2, that is, the shift point, first, the control oil pressure acting on each of the first to fourth oil chambers 18 to 21 is released, and this state is adjusted. When the anchor end pin 6 is screwed in, the left locking portion 3a of the brake band 3 is moved in the direction of the right locking portion 3b, and the right locking portion 3b collides with the stopper 1a formed on the case 1. The evacuation to the right is prevented. When the anchor end pin 6 is further screwed in this state, the locking portion 3a on the left and the locking portion 3 on the right
When the distance from b is small, the brake band 3 changes to a small diameter, and the clutch drum is tightened. Brake band 3
However, when the clutch drum 2 is tightened, the screwing load of the anchor end pin 6 suddenly becomes excessively large, so that further screwing cannot be performed. In this case, the screwing load of the anchor end pin 6 is reduced by the stopper 1a provided on the case 1.
The load is applied to the stem 11 and hence the retainer 1
3 and the first piston 15 to the third piston 17 are not applied. Next, when the anchor end pin 6 is loosened by a predetermined amount, the brake band 3 returns to a large diameter and the tightening of the clutch drum 2 is released, whereby the initial gap of the brake band 3 to the clutch drum 2 is set to a predetermined value. .

[0013]

As is clear from the above description, in the present invention, since the screwing load by the anchor end pin is received by the stopper provided in the case, a large load is applied to each piston and the retainer when adjusting the initial clearance of the brake band. Will not be added. Accordingly, it is possible to prevent damage to the pistons and the retainers, and to provide an effect of reducing the weight and cost by forming the pistons and the retainers with a plastic material.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Case 1a Stopper 1b Left side 2 Clutch drum 3 Brake band 3a Locking part 3b Locking part 6 Anchor end pin 10 Hydraulic servo mechanism 11 Stem 11a Left end 12 Storage chamber 13 Retainer 15 First piston 16 Second piston 17 Third piston 18th 1 oil chamber 19 2nd oil chamber 20 3rd oil chamber 21 4th oil chamber 22 1st return spring 23 2nd return spring

Claims (1)

(57) [Scope of request for utility model registration] 1. A brake band is suspended around a clutch drum provided in a case, and a pair of locking portions protruding radially outward and facing each other are provided at both ends of the brake band, and one of the locking portions is provided on one of the locking portions. An anchor end pin screw-fitted to the case is brought into contact with the tangentially outer side, and the stem of the hydraulic servo mechanism is brought into contact with the other engaging portion from the tangentially outer side. In the band brake device for an automatic transmission in which a portion is moved in a tangential direction, a stopper is provided on the case to protrude inward, and the stopper is moved tangentially outward when the brake band is not operated. A band brake device for an automatic transmission, wherein the band brake device is abutted from one side.