JPH0663941U - accumulator - Google Patents

Abstract

(57) [Summary] [Purpose] To enable easy and reliable incorporation of accumulator pistons. A structure in which a return spring 5 is interposed between the accumulator piston 2 and a housing 1 in a cylindrical portion 2b of the accumulator piston 2 and the return spring 5 is incorporated in a preloaded state. As a result, the return spring 5
Unlike when compressing from the free state at the time of assembling, there is no buckling and the assembling work becomes easy. Also,
The O-ring 4 is not hooked on the housing 1 side and damaged, and contributes to maintaining the sealing property of the piston 2.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an accumulator, and more particularly to a structure for mounting an accumulator piston on an accumulator housing.

[0002]

[Prior art]

An automatic transmission of an automobile incorporates a device called an accumulator in order to reduce a shift shock. The accumulator is a device that creates a semi-engaged state for a short time when the clutch and brake are engaged / disengaged, and its structure is shown in FIG. The accumulator housing (hereinafter, simply referred to as housing 40) has an opening at the lower side in the figure, and the inside is formed by a large diameter portion 40a and a small diameter portion 40b on the back side. An accumulator piston (hereinafter simply referred to as piston 41) is incorporated in the housing 40, and can be displaced in the axial direction by the clutch hydraulic pressure or the like acting through a through hole 45 formed in the cover 42. Has become. Further, the piston main body 46 of the piston 41 has a large-diameter flange portion 41a slidably in contact with the wall surface of the large-diameter portion 40a, a cylindrical portion 41c standing upright from the large-diameter flange portion 41a along the axis, and a cylindrical portion 41c. A small diameter flange portion 41b formed at the tip of the housing 40 and slidingly contacting the small diameter portion 40b of the housing 40. Further, a return spring 43 is housed in the cylindrical portion 41c so that the upper end side in the figure contacts the wall surface of the housing 40. I am doing it.

[Problems to be solved by the device]

 In the case of the above structure, the assembling procedure is as follows. The return spring 43 is housed in the tubular portion 41c of the piston body 46 in advance, and is assembled into the housing 40, or the return spring 43 alone is first inserted into the housing 40. After that, the piston body 46 is assembled, and then the cover 42 is attached, which is one of the procedures. In any case, it is necessary to close the cover 42 while compressing the return spring 43. When performing this closing work, as shown in FIG. 11, the return spring 43 is set from the free length. Since it is compressed, it is not easy to compress it in a normal state along its axis to prevent buckling. In addition, since the accumulator can be installed in multiple places in the automatic transmission mechanism, the whole work was extremely troublesome and time-consuming. Therefore, for example, even if mechanization is performed so that such work can be performed all at once, the following problems still remain. That is, when the return spring 43 has a free length, as is apparent from FIG. 11, even when the tip of the return spring 43 abuts against the wall surface of the housing 40, the small diameter flange portion 41b of the piston 41 has a small diameter. It is located outside the portion 40b. Therefore, when the return spring 43 is pushed in and the small diameter flange portion 41b and the small diameter portion 40b are not aligned due to buckling or displacement, the return spring 43 is fitted into the small diameter flange portion 41b. Also, the O-ring 44 is forcibly pushed in while being caught by the opening edge of the small diameter portion 40b. If such a thing is done, the O-ring 44 will be damaged or cut, and the sealing property will be adversely affected. Further, if the O-ring 47 of the large-diameter flange portion 41a is also rubbed against the inner wall surface of the large-diameter portion 40a if it is assembled in the inclined posture, the wear and damage progresses at an early stage.

The present invention has been devised and devised in view of the above problems, and an object thereof is to provide an accumulator capable of easily and reliably assembling a piston in a housing. is there.

[0005]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the structure of the present invention is incorporated in an automatic transmission for a vehicle, and an axially displaceable piston is incorporated in a housing having an opening closed by a cover. In the accumulator in which a return spring for interposing between the wall surface side of the housing and the piston body in the return direction for urging the piston body in the return direction is housed in the cylindrical portion formed at the tip of the piston body of the piston, It is characterized in that the return spring is housed in the tubular portion of the main body in a state in which the return spring is compressively deformable and is preloaded until the length of the return spring is almost assembled.

[0006]

[Action]

 Since the return spring is preloaded in the cylinder of the piston, that is, the spring length is almost equivalent to the length at the time of assembly, it is not necessary to compress the return spring during the assembly work. Is installed in the housing as it is. When the clutch hydraulic pressure is applied after the assembly, the piston is displaced while compressing the return spring.

[0007]

[Effect of device]

 The effects of the present invention are as follows. Since the return spring is pre-compressed and integrated with the piston body, unlike the conventional method where it is compressed during assembly work, it does not cause buckling and allows smooth operation. It is possible and can be assembled in a regular condition.

[0008]

【Example】

 Embodiments embodying the present invention will be described below in detail with reference to the drawings. 1 and 2 show a first embodiment of the present invention, in which a metal (aluminum) housing 1 incorporated in a clutch hydraulic circuit of an automobile is formed in a tubular shape opening downward in the drawing. ing. As in the conventional case, the inside of the housing 1 is formed of a large diameter portion 1a and a small diameter portion 1b continuous from here to the inner side through a tapered surface 1c.

The piston 2 slidably incorporated in the housing 1 has a piston body 27 formed of a synthetic resin material. A large-diameter flange portion 2a whose outer peripheral edge is in sliding contact with the large-diameter portion 1a of the housing 1 is formed at one end portion (the lower end portion in FIG. 1). The large-diameter flange portion 2a is formed in a truncated cone shape without a bottom surface, and an O-ring 3 for sealing is fitted to the outer peripheral edge thereof. A cylindrical portion 2b is erected concentrically on the upper surface of the large diameter flange portion 2a so that it can be inserted into the small diameter portion 1b of the housing 1. Further, an O-ring 4 for sealing the small diameter portion 1b is fitted to the outer peripheral edge of the tip of the cylindrical portion 2b. Further, a regulating shaft 6 for regulating the tilting of the return spring 5 is formed at the center of the bottom surface of the tubular portion 2b so as to be concentric with the opening edge of the tubular portion 2b and at substantially the same height. A locking sleeve 9 for engaging with a pressing member 8, which will be described later, is fitted to the tip of the regulation shaft 6. The locking sleeve 9 is formed by rolling a metal leaf spring material into a cylindrical shape. Here, a plurality of locking claws 10a and 10b are formed by cutting and raising, respectively. The locking claw 10b is raised inward and bites into the restriction shaft 6 so that the locking sleeve 9 does not come off from the restriction shaft 6. On the contrary, the upper engaging claw 10b is raised outward and serves as a catch on the pressing member 8.

A return spring 5 for urging the piston body 27 in the returning direction is housed inside the tubular portion 2b, and its lower end side is locked to a spring seat 7 formed on the bottom surface of the tubular portion 2b. I am allowed. The upper end of the return spring 5 is pressed by the pressing member 8 so that the return spring 5 can be assembled in a pre-compressed state. The pressing member 8 is formed into a cylindrical shape that can be inserted into the return spring 5, and at one end side thereof, a collar portion 8a that abuts on the bottom surface of the small diameter portion 1b of the housing 1 when the piston 2 is assembled is projected and the return spring 5 is attached. It is designed to be locked at the upper end. A hollow shaft portion 8b that can be inserted into the cylindrical portion 2b of the piston body 27 from the flange portion 8a and is open to both ends is erected coaxially. Further, a locking edge 8c extends inwardly along the entire circumference at the tip end side opening edge of the hollow shaft portion 8b and can be engaged with the upper locking claw 10a of the locking sleeve 9. The return spring 5 can be disengaged by compression deformation. However, when the piston 2 is assembled with the return spring 5 preloaded as described above, the entire piston 2 can be stored as it is in the housing 1 (without compressing the return spring 5). In addition, when the collar portion 8a is abutted against the small diameter portion 1b of the housing 1, the tip of the tubular portion 2b is set to a length such that it can enter the small diameter portion 1b.

Since the first embodiment is configured as described above, when the piston 2 is assembled in the housing 1, the return spring 5 is already in the compressed length when assembled. , It is not necessary to push the return spring 5 into the housing 1 while compressing it, unlike the conventional case. After the piston 2 is inserted, the cover 11 is simply closed and the piston 2 can be assembled smoothly. You can Further, the dimension of the tip of the cylindrical portion 2b, that is, the O-ring 4 portion is already inserted into the small diameter portion 1b when it is inserted into the small diameter portion 1b, and the displacement of the return spring 5 at the time of pushing is also caused by the above. Since the piston 2 is not present, the piston 2 can be correctly inserted along the axial center of the housing 1, so that the O-ring 4 is prevented from being caught on the edge portion of the housing 1. Therefore, the sealability can be maintained by protecting the O-ring 4 from damage.

After the piston 2 is assembled, when the piston 2 rises against the return spring 5 by the action of the clutch hydraulic pressure or the like, the engaging edge 8 c and the upper engaging claw 10 a of the engaging sleeve 9 are arranged. The engagement with and disengages, and the entire locking sleeve 9 enters into the cylindrical portion 2b.

Various modifications can be made to the locking method between the piston 2 side and the pressing member 8. For example, what is shown in FIGS. 3 and 4 is a modification of the second embodiment of the present invention.

That is, a pair of claw edges 12 are formed so as to project inward at the opening edge of the cylindrical portion 2b of the piston body 27. The pressing member 8 is formed in a substantially cylindrical shape that opens toward the side facing the piston body 27, and a brim edge 13 projects along the entire circumference at the opening edge, and this brim edge 13 is shown in FIG. Notches 14 are provided at various places. As a result, the brim 13 can be bent in the direction of small constriction, can be inserted into the cylindrical portion 2b, and can be elastically engaged with the claw edge 12. The return spring 5 is housed inside the pressing member 8 and is elastically mounted between itself and the piston body 27. The return spring 5 is regulated to fall by a regulation shaft 15 formed in the cylindrical portion 2b of the piston body 27.

Since other configurations are the same as those of the first embodiment, the description thereof will be omitted by giving the same reference numerals to the drawings.

Also in the second embodiment configured as described above, since the return spring 5 can be assembled in the piston body 27 in a compressed state, the same effect as that of the first embodiment can be obtained. Can be demonstrated.

FIGS. 5 and 6 show a third embodiment of the present invention. In this example, a pair of flexible locking pieces 16 for preventing slipping out are formed at the tip of the regulation shaft 15. In the molded state, both of the flexible locking pieces 16 extend obliquely upward as shown by the imaginary line in FIG. 6, but when the pressing member 8 is inserted into the regulating shaft 15, the locking edges 8c are formed. Is gradually inverted along the gradient of the above, and after passing through the locking edge 8c, the elastic force causes the wall surface in the pressing member 8 to be stretched and the inverted state is maintained. As a result, the pressing member 8 and the piston body 27 are engaged with each other, and the return spring 5 is held in a compressed state.

According to the third embodiment as described above, it is possible to obtain the same effects as those of the first and second embodiments.

7 and 8 show a fourth embodiment of the present invention, in which the return spring 5 previously held in a compressed state can be incorporated into the piston body 27 by itself. It is a thing. That is, the return spring 5 is designed to be compressed and held by the pair of pressing members 17 and 18 arranged inside and outside the tubular portion 2b, and the pressing member 17 arranged outside is a seat piece 19 for the return spring 5. A projecting shaft 28 is projected from the center of the shaft, and a locking portion 29 is formed at the tip thereof. On the other hand, the inner pressing member 18 has a hollow shaft portion 21 protruding from the upper surface of the sheet piece 20 into which the regulating shaft 15 can be inserted. Further, at the opening edge of the hollow shaft portion 21, locking projections 22 which can be elastically engaged with the locking portion 29 are arranged at three positions in the drawing. Further, the sheet piece 20 is provided with four retaining portions 23 at equal intervals in the figure, and each of them has a pair of retaining pieces 30 that are allowed to bend and deform inward. It can be inserted into the cylindrical portion 2b of the piston body 27 by being slightly deformed, and when it is inserted into the bottom surface of the cylindrical portion, it elastically returns to the enlarged portion 31 formed on the bottom surface of the cylindrical portion 2b. Engagement is possible, and this prevents the return spring 5 from falling off.

Other configurations are almost the same as those of the above-described respective embodiments, and thus the same operational effect can be exhibited.

By the way, there is a type of accumulator with a reverse spring 25, as shown in FIG. 9, but the present invention is also applicable to this type. In this type, a reverse spring 25 is interposed between the large-diameter flange portion 2a of the piston body 27 and the cover 11 side to urge the piston body 27 in the pushing-up direction. In this case, a mounting protrusion 26 for the reverse spring 25 is integrally formed at the center of the bottom surface of the large-diameter flange portion 2a, and one end of the reverse spring 25 can be press-fitted. With this configuration, the reverse spring 25 can be integrated with the piston body 27 with a simple structure, and the assembling work can be easily performed.

[Brief description of drawings]

FIG. 1 is a sectional view showing a state in which a piston according to a first embodiment is assembled.

FIG. 2 is an exploded perspective view of the same.

FIG. 3 is a sectional view showing a piston according to a second embodiment.

FIG. 4 is an exploded perspective view of the same.

FIG. 5 is a sectional view showing a piston according to a third embodiment.

FIG. 6 is an enlarged view of a flexible locking piece portion.

FIG. 7 is a sectional view showing a piston according to a fourth embodiment.

FIG. 8 is an exploded perspective view of the same.

FIG. 9 is a sectional view showing a piston with a reverse spring.

FIG. 10 is a cross-sectional view showing an assembled state of a conventional piston.

FIG. 11 is a sectional view showing the same assembling work.

[Explanation of symbols]

 1 ... Housing 2 ... Piston 4 ... O-ring 5 ... Return spring 8 ... Pressing member 27 ... Piston body

Claims (1)

[Scope of utility model registration request] 1. An accumulator piston, which is incorporated in a clutch hydraulic circuit of an automatic transmission for a vehicle and has an opening closed by a cover, is provided with an accumulator piston displaceable in the axial direction, and the accumulator piston. An accumulator in which a return spring that is interposed between the wall portion of the accumulator housing and urges the piston body in the return direction is housed in a cylinder portion formed at the tip of the piston body of An accumulator characterized in that the return spring is accommodated in the part in a state in which the return spring is compressively deformable and is preloaded until the length of the return spring is almost assembling.