JP2506251Y2 - Accumulator structure - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piston type accumulator in which a piston is slidably fitted in an outer case.

[0002]

2. Description of the Related Art A piston-type accumulator is used in an anti-lock brake system (ABS) or the like in which a braking force is finely controlled at the time of sudden braking to prevent a tire lock and a steering operation can be performed while braking. . As shown in FIG. 3, this accumulator has a piston 1 inside a cylindrical outer case 101 with a bottom.
02 is slidably fitted, seals 103, 103 are fitted on the outer circumference of the piston 102, and a cap 104 is attached to the opening of the outer case 101. The ring 105 is fitted, and nitrogen gas is sealed in the gas chamber S1 to plug the plug bolt 106.
There is a liquid chamber S2 filled with hydraulic oil while being sealed with.

[0003]

However, in the above-mentioned conventional accumulator structure, the gas on the gas chamber side passes through the seal 103 from the gap between the inner circumference of the outer case and the outer circumference of the piston to the hydraulic fluid chamber. However, air may be mixed into the system, which may cause a delay in the operation of the ABS and reduce the performance.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention proposes that a piston incorporated in an outer case is a bottomed cylindrical member having one end opened, and a free piston is slidable in the piston. A piston and a liquid chamber and a piston bottom portion defined between the free piston and the outer case side portion, in which a pressurized gas is enclosed in a gas chamber defined between the piston bottom portion and the free piston. The liquid was filled in a liquid chamber defined between the outer case and the side portion.

[0005]

Operation: Even if a part of the gas in the gas chamber permeates into the liquid chamber defined between the inner circumference of the piston and the outer circumference of the free piston and the side portion of the outer case, this liquid chamber Since it takes a very long time to reach a saturated state, it does not substantially permeate from this liquid chamber between the inner circumference of the outer case and the outer circumference of the piston and enter the working fluid chamber.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 is a sectional view of an accumulator to which the present invention is applied, and FIG. 2 is a sectional view showing an assembling procedure of the accumulator.

A bottomed tubular piston 2 is slidably fitted in the bottomed tubular outer case 1 through an opening, and a free piston 3 is slidably fitted in the piston 2. ,
Further, a cap 4 is fixed to the opening end of the outer case 1 so that a gas chamber S1 is provided between the bottom 2a of the piston 2 and the free piston 3 and a liquid chamber is provided between the free piston 3 and the bottom 1a of the outer case 1. S2, the bottom 2 of the piston 2
A hydraulic fluid chamber S3 is defined between a and the cap 4, and pressurized nitrogen gas is sealed in the gas chamber S1.
2 is filled with working oil from the filling hole 5 of the outer case 1 and then the ball 6 is caulked and sealed, and the working fluid chamber S3 is filled with working oil.

Further, an O-ring 7 and backup rings 8 and 8 are fitted on the outer circumference of the piston 2 and the outer circumference of the free piston 3, respectively, and a stopper for preventing the free piston 3 from falling off on the inner circumference of the piston 2. A ring 9 is fitted and the cap 4 is formed with a through hole 10 communicating with the antilock brake system.

In order to fill the pressurized gas in the gas chamber S1 between the piston 2 and the free piston 3, as shown in FIG. 2, the piston 2 is held at the end of the holder 11 and the inside of the holder 11 is held. The free piston 3 is slidably held in the holder 11, the gas is pumped from the hole 12 formed in the holder 11, and the free piston 3 is pushed by the rod 13 to be fitted into the piston 2 and the stopper ring 9 is fitted therein. Then, after the piston 2 and the free piston 3 are integrated, they are fitted into the outer case 1.

In the accumulator thus constructed, the high-pressure hydraulic fluid is pumped into the hydraulic fluid chamber S3 by a pump (not shown) and is sealed by a solenoid valve (not shown) in a state where the hydraulic fluid and the gas are balanced at a specified pressure. During operation of the system, which requires high-pressure hydraulic fluid, the solenoid valve is turned on and the hydraulic fluid chamber S
The hydraulic fluid is discharged from 3, and then the high-pressure hydraulic fluid necessary for system operation is accumulated again.

If a part of the gas in the gas chamber S1 permeates between the inner circumference of the piston 2 and the outer circumference of the free piston 3, this gas enters the liquid chamber S2 and the liquid chamber S2.
It takes a very long time, for example, about 10 years for the amount of the gas that dissolves in the working oil in the liquid chamber S2 to become saturated, so that the liquid chamber S2 becomes saturated and the piston 2 Gas permeates between the outer circumference and the inner circumference of the outer case 1 and enters the hydraulic fluid chamber S3, which is substantially the same.

[0012]

As described above, according to the present invention, the free piston is slidably fitted in the piston in the outer case, and a gas chamber is provided between the piston and the free piston. Since a liquid chamber for enclosing the hydraulic oil and a hydraulic liquid chamber for filling the hydraulic oil are arranged on both sides of the chamber, the gas in the gas chamber permeates into the liquid chamber from between the inner circumference of the piston and the outer circumference of the free piston. , It takes an extremely long time for this liquid chamber to reach a saturated state, so there is practically no possibility of further penetrating from this liquid chamber between the inner circumference of the outer case and the outer circumference of the piston and entering the working fluid chamber. ,
Permeation of gas from the gas chamber to the hydraulic fluid chamber can be prevented.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an accumulator to which the present invention is applied.

FIG. 2 is a sectional view showing an assembling procedure of the accumulator.

FIG. 3 is a cross-sectional view of a conventional accumulator.

[Explanation of symbols]

1 ... Outer case, 2 ... Piston, 3 ... Free piston, 4 ... Cap, S1 ... Gas chamber, S2 ... Liquid chamber, S3
... hydraulic fluid chamber.

Claims (1)

(57) [Scope of utility model registration request] 1. A piston type accumulator in which a piston is slidably fitted in an outer case, wherein the piston is a bottomed cylindrical member having one end opened, and a free piston is slidably fitted in the piston. Then, a gas chamber in which a pressurized gas is filled is defined between the bottom portion of the piston and the free piston, and between the free piston and the outer case side portion and between the piston bottom portion and the outer case side portion. An accumulator structure characterized by defining a liquid chamber in which a liquid is sealed between.