JP2855306B2 - Accumulator device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an accumulator device in a hydraulic control device of an automatic transmission mounted on an automobile, and more particularly, to an arrangement structure of an oil chamber side spring in the accumulator device.

[0002]

2. Description of the Related Art Generally, an automatic transmission has a planetary speed change gear mechanism, and a plurality of shift speeds are achieved by engaging or disengaging predetermined elements of the planetary speed change gear mechanism with clutches and brakes. ing. Also,
The clutch and the brake have a hydraulic servo which operates by being supplied with a hydraulic pressure. The hydraulic servo is selectively supplied and discharged by a hydraulic control device having a plurality of switching valves and controlled.

[0003] The hydraulic control device is provided with an accumulator for improving the engagement characteristics of the hydraulic servo and reducing shock during shifting. The accumulator is formed by a cylinder chamber having a cylindrical inner peripheral surface, a piston slidably fitted into the cylinder chamber and urged by a back pressure chamber-side spring, and is formed by the cylinder chamber and the piston, and communicates with a hydraulic servo. When the oil pressure is supplied to the oil chamber, the piston moves and presses the spring on the back pressure chamber side, whereby the oil pressure is accumulated in the oil chamber, and as a result, the engagement characteristics of the hydraulic servo are reduced. The structure is smooth and shift shock is reduced.

As a method of further improving the hydraulic characteristics of the hydraulic servo engagement, there is a method in which a spring is also provided on the oil chamber side. Japanese Patent Application Laid-Open No. 64-35101 discloses a structure for disposing the spring on the oil chamber side. Proposed. In this structure, a recess with a small diameter on the inlet side and a large diameter on the back side is provided on the end face of the piston on the oil chamber side, one end of the oil chamber side spring is fixed to the retainer, and a snap ring is provided between the bottom of the recess and the small diameter section. Thus, the oil chamber side spring is securely locked to the piston, and the straightness of the oil chamber side spring is accurately maintained.

[0005]

However, in the above-described conventional accumulator, the piston becomes longer in the axial direction by an amount corresponding to the fitting portion of the snap ring, and the length in which the back pressure chamber side spring can be disposed becomes shorter accordingly. However, there is a problem that it is difficult to obtain a desired spring characteristic, which affects hydraulic characteristics. In other words, recently, a small automatic transmission is required, and a small accumulator in the hydraulic control device of the automatic transmission is also required. It is necessary to shorten the axial dimension and increase the piston stroke. On the other hand, the oil pressure supplied to the oil chamber tends to increase due to the high output of the vehicle itself, and it is necessary to increase the wire diameter to increase the spring load so that the back pressure chamber side spring can respond to the high oil pressure. However, doing so results in an increase in the maximum compression length of the back-pressure chamber-side spring, making it difficult to increase the piston stroke as described above. Therefore, in order to improve the hydraulic characteristics under such circumstances, it is difficult to increase the axial dimension of the piston and to dispose the oil chamber side spring.
Conversely, it is difficult to set the load of the back pressure chamber side spring, resulting in impaired hydraulic characteristics.

Further, since the oil chamber side spring is fixed via the retainer by the snap ring, there is a problem that the snap ring fitting portion requires machining and the cost is increased. That is,
Usually, the piston of the accumulator is made of aluminum for the purpose of weight reduction and is manufactured by a die-casting die. Therefore, the die-casting die is restricted and the above-mentioned concave portion cannot be formed in advance. This is because it is necessary to form

Accordingly, the present invention solves the above-mentioned problems of the conventional accumulator device, suppresses an increase in cost with a simple structure, and ensures that the oil chamber side spring is securely mounted without increasing the axial dimension of the piston. It is an object to provide an accumulator device that can be fixed.

[0008]

For this purpose, in the accumulator device according to the present invention, a cylinder having a cylindrical inner peripheral surface having one end closed and the other end opened is slidably fitted in the cylinder. An inserted piston, a back pressure chamber side spring disposed between the piston and the one end of the cylinder, a hole having a diameter smaller than an outer diameter of the piston is formed, and the other end of the piston A flat plate disposed at the opening at the other end of the cylinder so as to regulate movement to the end, a recess is formed, and hydraulic pressure is applied between the recess, the piston, and the cylinder. A cover fixed to the opening on the other end side of the cylinder via the plate so as to form an oil chamber communicating with a servo, and one end disposed between the bottom surface of the concave portion of the cover and the piston. An oil chamber-side spring that is inserted into the hole of the plate and abuts on the piston; and a retainer that has the other end of the oil chamber-side spring fixed and fixed between the cover and the plate. It is characterized by.

[0009]

According to the above-described structure, the accumulator device of the present invention can securely fix the oil chamber side spring between the cover and the plate having the concave portion without fixing the spring to the piston. And the axial dimension of the piston can be reduced, so that there is no effect on the back pressure chamber side spring. Further, since the retainer is not fixed by the snap ring, no special processing is required for the cover, and the cover can be easily formed by casting or the like, so that an increase in cost due to machining can be suppressed.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view of an accumulator device according to the present invention.

The accumulator device 1 is used in a hydraulic control device of an automatic transmission, and gradually increases the hydraulic pressure of a hydraulic servo to reduce a shock during shifting. The accumulator device 1 includes a cylinder 2 having a cylindrical inner peripheral surface, one end of which is closed, a piston 3 slidably disposed on the inner peripheral surface of the cylinder 2, and closing an opening side of the cylinder 2. Between the cover 5, the plater 4 interposed between the cylinder 2 and the cover 5, the back pressure chamber-side spring 8 disposed between the cylinder 2 and the piston 3, and between the cover 5 and the piston 3 An oil chamber-side spring 7 disposed via a retainer 6.

The cylinder 2 has a cylindrical inner peripheral surface, one end of which is closed by a closing wall 23. A piston 3 is disposed on the inner peripheral surface so as to be slidable in the axial direction. The back pressure chamber 9 is formed on the side of the closing wall 23 between them, and the oil chamber 10 is formed on the opposite side. The back pressure chamber 9 is supplied with hydraulic pressure from an accumulator back pressure control valve of a hydraulic control device (not shown) from an accumulator back pressure control oil passage 11 connected to a port 21 opened to the closing wall 23. The oil chamber 10 has a port 22 opened to the cylinder 2.
The hydraulic pressure is supplied from the engaging hydraulic oil passage 12 connected to the hydraulic servo and connected to the hydraulic servo. The oil pressure is accumulated in the oil chamber 10 so that the increase in the oil pressure is moderated.

The piston 3 comprises a cylindrical portion 33 and a wall portion 34. The upward movement of the piston 3 is regulated by contacting the closing wall 23, and the downward movement of the piston 3 is regulated by contacting the plate 4. An annular groove 32 is formed in the outer periphery of the cylindrical portion 33, and an O-ring 31 for partitioning the back pressure chamber 9 and the oil chamber 10 in a liquid-tight manner is provided. The back pressure chamber side spring 8 is in contact with the back pressure chamber 9 side of the wall portion 34, and the oil chamber side spring 8 is in contact with the oil chamber 10 side.

The cover 5 is fixed to the cylinder 2 via the plate 4 so as to close the oil chamber 10. Cover 5
As shown in FIG. 2, a spring-arranged chamber 51 having a columnar space, which is a concave portion, is formed so as to accommodate the oil chamber-side spring 7 and the retainer 6, and is further opposed to the projection 52.
Are formed at two places. The spring installation chamber 51 and the projection 52 are formed by die casting.

The oil chamber side spring 7 is fixed to the retainer 6 by caulking. As shown in FIG. 3, the retainer 6 has an annular flat plate portion 63, and the inner peripheral side is bent to form a caulked portion 61, and the outer peripheral side is opposed to two circumferential portions at a flange portion 62. It is formed by being bent upward. Since the axial length of the flange portion 62 is substantially the same as the axial length of the spring installation chamber 51 of the cover 5, the oil chamber side spring 7 and the retainer 6 are connected to the spring installation chamber 51 of the cover 5. When the cover 5 is mounted on the cylinder 2 via the plate 4, the flange portion 62 of the retainer 6 is sandwiched and fixed between the bottom surface 53 of the cover 5 and the plate 4. . At this time, the flange portion 62 is housed in the protrusion 52 of the cover 5.

When the oil chamber-side spring 7 is assembled to the plate 4, the oil chamber-side spring is
A circular hole 41 is formed so as to be able to abut on the hole 4.
The diameter of the hole 41 is such that the plate 4
Is restricted to a smaller diameter than the diameter of the piston 3.

FIG. 4 is a sectional view showing a state where the accumulator device 1 is incorporated in a valve body 100 which is a hydraulic control device of an automatic transmission. Body 10 of valve body 100
1 includes a plurality of valves 111, 112, 113, 114, 1 for selectively supplying hydraulic pressure to a hydraulic servo of the automatic transmission.
15, 116, and 117, and the accumulator 12 in addition to the accumulator device 1 to which the present invention is applied.
1, 122 and 123 are incorporated.

The main body 101 of the valve body 100 forms a cylinder 2 by directly forming a cylindrical inner peripheral surface.
The cover 5 is fixed to the main body 101 via the plate 4 by bolts 140.

Next, the operation of the accumulator device 1 according to the present invention will be described. In a state where the hydraulic pressure is not supplied to the engagement hydraulic oil passage 12, the pressing force of the hydraulic pressure supplied from the accumulator back pressure control oil passage into the back pressure chamber side spring 8 and the back pressure chamber 9 is the pressing force of the reverse spring 7. To excel, the piston 3 rests on a plate 4 as shown on the left side of FIG. When the hydraulic pressure is supplied to the engagement hydraulic oil passage 12, the hydraulic pressure in the oil chamber 10 rises, and the hydraulic pressure in the oil chamber-side spring 7 and the oil chamber 10 is reduced by the back pressure chamber-side spring 8 and the back pressure chamber 9. , The piston 3 starts moving upward in the figure.

When the oil pressure in the oil chamber 10 further rises and the piston 3 reaches the position where the oil chamber side spring 7 can be extended, the pressing force of the oil chamber side spring 7 does not act on the piston 3 and the piston 3 It moves only by the pressing force of the oil pressure in the oil chamber 10. This oil chamber side spring 7
While the pressing force is acting, the hydraulic servo engagement hydraulic characteristics can be changed by the oil chamber side spring 7. When the oil pressure in the oil chamber 10 further rises, the piston 3 comes into contact with the closing wall 23 of the cylinder 2 as shown on the right side of FIG.

In this embodiment, the accumulator device 1 is incorporated in the valve body 100. However, the accumulator device 1 may be incorporated in a case of an automatic transmission. In this case, the cylinder 2 is formed integrally with the case and the cover 5 is fixed to the case. do it. Further, the cover may be formed integrally with the valve body.

As described above, according to the accumulator device of the present embodiment to which the present invention is applied, the oil chamber side spring is not fixed to the piston, but is clamped and fixed between the cover formed with the concave portion and the plate. As a result, the oil chamber side spring is securely fixed, the axial dimension of the piston can be reduced, and there is no influence on the back pressure chamber side spring. Furthermore, since the retainer is not fixed with a snap ring, there is no need for special processing on the cover, and it can be easily configured by casting, etc., so that the cost increase due to machining can be suppressed,
Further, since a snap ring is not required, the number of parts can be reduced.

The present invention is not limited to the above embodiments, but can be variously modified based on the technical concept described in the claims of the present invention. It is not excluded from.

[Brief description of the drawings]

FIG. 1 is a sectional view of an accumulator device of the present invention.

FIG. 2 is a cross-sectional view showing a shape of a spring installation chamber of a cover.

FIG. 3 is a top view of the retainer.

FIG. 4 is a sectional view of a valve body to which the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Accumulator apparatus 2 ... Cylinder 3 ... Piston 4 ... Plate 5 ... Cover 6 ... Retainer 7 ... Oil chamber side spring

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Fumitomo Yokoyama 10 Takane, Fujii-machi, Anjo-shi, Aichi Examiner, Aisin AW Co., Ltd. Shogo Tanai (56) References JP-A 64-35101 JP, A) JP-A 3-73757 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F15B 1/24 F16H 61/04

Claims (4)

(57) [Claims] 1. A cylinder having a cylindrical inner peripheral surface having one end closed and the other end opened, a piston slidably fitted in the cylinder, and the piston and the one end of the cylinder. And a back pressure chamber side spring disposed between the spring and the other end of the cylinder so that a hole having a diameter smaller than the outer diameter of the piston is formed and movement of the piston to the other end side is restricted. A flat plate disposed at an end opening, a recess formed therein, and the cylinder of the cylinder being formed so as to form an oil chamber communicating with a hydraulic servo between the recess, the piston and the cylinder. A cover fixed to the opening at the other end via the plate, and an oil chamber disposed between the bottom surface of the concave portion of the cover and the piston and one end of which is in contact with the piston through a hole in the plate. A side spring, The other end of the oil chamber-side spring is fixed, and the accumulator device comprises a retainer sandwiched and fixed between the cover and the plate. 2. The retainer has a flat portion and a flange portion extending outward from the flat portion and bent at a substantially right angle. The oil chamber side spring is fixed to the flat portion, 2. The accumulator device according to claim 1, wherein a flange is fixedly held between said cover and said plate. 3. The retainer according to claim 2, wherein the flat portion contacts the bottom surface of the concave portion of the cover, and the flange portion extends to an opening side of the concave portion. An accumulator device according to any one of the preceding claims. 4. The accumulator device according to claim 1, wherein said cylinder is formed integrally with a valve body which is a hydraulic control device of an automatic transmission.