JP4923331B2 - Hydraulic pressure accumulator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hydraulic pressure accumulator that supplies hydraulic pressure to an external operating device.
[0002]
[Prior art]
As a conventional hydraulic pressure accumulator, there is one disclosed in JP-A-3-243455. The hydraulic pressure accumulator described therein boosts brake fluid stored in a reservoir by a hydraulic pump and stores the pressure in a pressure accumulator, and the hydraulic pressure stored in the pressure accumulator is used as a vehicle brake hydraulic pressure as an external operating device. It is used as a hydraulic pressure source for boosters.
[0003]
[Problems to be solved by the invention]
When the hydraulic booster as an external operating device is provided with a spool valve as disclosed in the above patent publication, for example, when the hydraulic pump is not operated for a long time, such as when the vehicle is stopped, the accumulator The accumulated hydraulic pressure is discharged to the reservoir via the spool valve of the hydraulic booster, and the hydraulic pressure in the accumulator is extremely reduced (for example, zero).
[0004]
As disclosed in Japanese Patent Laid-Open No. 2000-320501, a normal pressure accumulator includes a metal bellows that divides the inside of a housing into an air chamber and a liquid chamber, and a seal member provided on the metal bellows. When the hydraulic pressure accumulated in the accumulator decreases, the seal member provided on the metal bellows comes into contact with the housing, shuts off the accumulator fluid chamber from the outside of the accumulator, and reduces the fluid pressure in the fluid chamber and the gas in the air chamber. The pressure is balanced to prevent the metal bellows from being burdened by the gas pressure.
[0005]
In order to maintain the sealing function, the pressure accumulator seal member takes measures such as having multiple members. However, if the pressure in the pressure accumulator drops extremely, the liquid chamber is disconnected from the outside of the pressure accumulator. Therefore, there is no change in that the seal member is burdened.
[0006]
Therefore, the present invention provides a hydraulic pressure accumulator that can prevent the hydraulic pressure of the pressure accumulator from being extremely reduced and maintain the sealing function of the seal member of the pressure accumulator with a simple configuration in order to solve the above problems. It is in.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the invention of claim 1 includes a hydraulic pump that boosts and discharges hydraulic fluid in a reservoir, accumulates the discharge pressure of the hydraulic pump, and stores the accumulated hydraulic pressure to an external actuator. In the hydraulic pressure accumulator including the pressure accumulator to be supplied, when the hydraulic pressure of the accumulator exceeds a predetermined pressure between the accumulator and the external actuator, the accumulator and the external actuator communicating between, when the hydraulic pressure of the accumulator is less than the predetermined pressure, a control valve for blocking between said accumulator and said external actuator,
Pressure detecting means is provided between the pressure accumulator and the control valve, and a predetermined value higher than the predetermined pressure is set as a threshold value, and the pressure detecting means has a hydraulic pressure of the pressure accumulator equal to or lower than the threshold value. When this is detected , the hydraulic pressure accumulator is characterized in that the hydraulic pump is operated .
[0008]
According to the invention of claim 1, when the hydraulic pressure of the pressure accumulator is less than or equal to a predetermined pressure, since the control valve that cuts off the pressure accumulator and the external operating device is provided, the hydraulic pressure pump is not operated for a long time. However, the hydraulic pressure of the pressure accumulator does not extremely decrease, and a burden is not imposed on the seal member of the pressure accumulator.
[0009]
Embodiment
Hereinafter, an embodiment according to the present invention will be described with reference to the drawings.
[0010]
FIG. 1 shows a hydraulic pressure accumulator 2 according to the present invention. The reservoir 4 is not intended to be limited to this, but stores, for example, brake fluid and communicates with the atmosphere. The hydraulic pump 8 driven by the electric motor 6 is connected to the reservoir 4 by, for example, a brake hose, and sucks the brake fluid stored in the reservoir 4 to increase the pressure. The pressure accumulator 10 is connected to the discharge port of the hydraulic pump 8 by piping, and accumulates the hydraulic pressure discharged by the hydraulic pump 8.
[0011]
FIG. 2 is a detailed view of the pressure accumulator 10. A metal bellows 14 is installed in the housing 12, and one end thereof is fixed at the ceiling of the housing 12. The other end of the metal bellows 14 is fixed to the plate 16, whereby the inside of the housing 12 is divided into an air chamber 18 in which high-pressure gas is sealed and a liquid chamber 20 in which brake fluid pressure is introduced. A seal member 22 having double annular seal portions 22 a and 22 b is fixed to the plate 16.
[0012]
The housing 12 is provided with an introduction hole 12a into which a hydraulic pressure is introduced at the lower end thereof, a gas sealing hole 12b is provided in the ceiling portion, and a sealing plug 24 is mounted in the sealing hole 12b.
[0013]
FIG. 2 shows the time when the hydraulic pressure is not accumulated in the pressure accumulator 10, and the seal member 22 is in contact with the housing 12, thereby shutting off the liquid chamber 20 and the hydraulic pressure system outside the pressure accumulator 10. At this time, a fluid pressure is generated in the fluid chamber 20 that balances with the pressure of the gas in the air chamber 18.
[0014]
When the hydraulic pressure is introduced into the pressure accumulator 10 from the introduction hole 12a, the seal member 22 is separated from the housing 12, and the metal bellows 14 is contracted upward in the figure to accumulate the hydraulic pressure in the liquid chamber 20.
[0015]
Returning to FIG. 1 again, the pressure sensor 26 detects the value of the hydraulic pressure accumulated in the accumulator 10, and transmits a low-pressure signal to a control device (not shown) when the hydraulic pressure value is equal to or less than a predetermined value PS.
[0016]
The control valve 30 is disposed between the pressure accumulator 10 and an external operating device 50 (for example, a vehicle brake hydraulic booster) that is not configured according to the present invention, and the hydraulic pressure accumulated in the pressure accumulator 10 is a predetermined pressure P0 or less. When the communication between the pressure accumulator 10 and the external actuator 50 is interrupted at a certain time and the hydraulic pressure accumulated in the pressure accumulator 10 exceeds a predetermined pressure P0, the pressure accumulator 10 and the external actuator 50 Communicate between them.
[0017]
In the control valve 30, a ball valve 30b is disposed in a valve body 30a, and a valve seat 30c that is in contact with the ball valve 30b is installed in the valve body 30a. A valve spring 30d is interposed between the ball valve 30b and the valve body 30a to urge the ball valve 30b toward the valve seat 30c.
[0018]
The stepped plunger 30e disposed in the valve body 30a has a large diameter portion 30e1 at one end and a stick portion 30e2 at the other end, and the stick portion 30e2 can come into contact with the ball valve 30b. The stepped plunger 30e further includes a stepped portion 30e3, and a plunger spring 30f is interposed between the stepped portion 30e3 and the valve body 30a to urge the stepped plunger 30e downward in the drawing.
[0019]
The valve body 30a includes an input chamber 32, an output chamber 34, a spring chamber 36 in which a spring 30f is stored, and a pilot chamber 38, and the ball valve 30b blocks between the input chamber 32 and the output chamber 34. It is possible. The valve body 30a is provided with an inlet port 40, an outlet port 42, an atmospheric port 44, and a pilot port 46. As shown, the input chamber 32 communicates with the accumulator 10 via an inlet port 40, the output chamber 34 communicates with an external actuator 50 via an outlet port 42, and the spring chamber 36 via an atmospheric port 44. The pilot chamber 38 communicates with the pressure accumulator 10 through a pilot port 46. The check valve 60 permits the flow of the brake fluid only in the direction from the hydraulic pump 8 to the accumulator 10 as shown in the figure.
[0020]
Next, the operation of the hydraulic pressure accumulator 2 according to the present invention will be described with reference to FIGS. 1 and 3. FIG. 1 shows a case where the hydraulic pressure of the pressure accumulator 10 is equal to or lower than a predetermined pressure P0, the control valve 30 is closed, and the communication between the pressure accumulator 10 and the external operating device 50 is shut off. This represents the time when the hydraulic pressure of the pressure accumulator 10 exceeds the predetermined pressure P0, the control valve 30 is opened, and the pressure accumulator 10 and the external operating device 50 are communicated with each other.
[0021]
In the figure, the hydraulic pump 8 is driven by the electric motor 6, sucks the brake fluid in the reservoir 4 to increase its pressure, and sends it to the pressure accumulator 10 via the check valve 60.
[0022]
The hydraulic pressure sent to the pressure accumulator 10 is accumulated in the pressure accumulator 10 by reducing the metal bellows 14 of the pressure accumulator 10 upward in FIG.
[0023]
The hydraulic pressure Pn accumulated in the pressure accumulator 10 is introduced into the input chamber 32 through the inlet port 40 and into the pilot chamber 38 through the pilot port 46, and the spring of the control valve 30. Since the chamber 36 communicates with the reservoir 4, the large-diameter portion 30e1 of the stepped plunger 30e is loaded with Pn × (S1-S2) by hydraulic pressure (S1 is a cross-sectional area of the large-diameter portion 30e1 of the stepped plunger 30e, (S2 represents the cross-sectional area of the portion where the plunger spring 30f of the stepped plunger 30e is installed) in FIG. Here, when the load by the plunger spring 30f is f1, the stepped plunger 30e has a load of Pn × (S1-S2) − (f1 + Pn × S3 + f2) (S3 is a seal area of the ball valve 30b, and f2 is a set of the valve spring 30d. The ball valve 30b is opened upward in the drawing. Therefore, if Pn × (S1−S2−S3)> f1 + f2, that is, Pn> (f1 + f2) / (S1−S2−S3) = P0, the control valve 30 opens, and the pressure accumulator 10 and the external actuator 50 To communicate with.
[0024]
In this case, the hydraulic pressure in the pressure accumulator 10 is sent to the external operating device 50 via the control valve 30 and consumed by the external operating device 50. Due to the consumption by the external actuator 50, the hydraulic pressure in the pressure accumulator 10 decreases, and the pressure sensor 26 causes the hydraulic pressure in the pressure accumulator 10 to be higher than a predetermined pressure: P0 = (f1 + f2) / (S1-S2-S3), When it is detected that the predetermined value is equal to or less than Ps (Ps> P0 is set), a low pressure signal is transmitted to a control device (not shown). The control device that has received the low-pressure signal drives the hydraulic pump 8 by transmitting a drive signal to the electric motor 6 to drive the electric motor 6, and stores the hydraulic pressure in the pressure accumulator 10 again.
[0025]
As shown in FIG. 3, for example, when the hydraulic pressure accumulator 2 is not operated for a long time due to, for example, a long stoppage of the vehicle, the hydraulic pressure Pn in the accumulator 10 gradually decreases via the external operating device 50, and Pn When ≦ (f1 + f2) / (S1-S2-S3) = P0, the ball valve 30b of the control valve 30 pushes down the stepped plunger 30e and closes the ball valve 30b. As a result, the communication between the pressure accumulator 10 and the external operating device 50 is blocked, so that the hydraulic pressure in the pressure accumulator 10 does not decrease any more.
[0026]
In the embodiment described above, the pressure sensor 26 is used as means for detecting the hydraulic pressure of the pressure accumulator 10. However, the present invention is not limited to this, and a pressure switch may be used.
[0027]
In the above-described embodiment, an example in which the hydraulic pressure accumulator according to the present invention is applied to a brake device has been shown. However, the present invention is not limited to this, and any hydraulic pressure for vehicles or non-vehicles can be used. Applicable to equipment.
[0028]
【Effect of the invention】
As described above, according to the present invention, since the hydraulic pressure in the pressure accumulator does not drop below a predetermined pressure, a highly reliable hydraulic pressure accumulator is obtained without placing a burden on the seal member of the pressure accumulator. be able to.
[Brief description of the drawings]
FIG. 1 is an overall view of a hydraulic pressure accumulator according to the present invention.
FIG. 2 is a cross-sectional view of a pressure accumulator.
FIG. 3 is a diagram illustrating when a control valve of a hydraulic pressure accumulator is closed.
[Explanation of symbols]
2 ... Hydraulic pressure accumulator 4 ... Reservoir 8 ... Hydraulic pump 10 ... Accumulator 30 ... Control valve 30b ... Ball valve 30c ... Valve seat 30e ... Stepped plunger 26 ... Pressure sensor 50 ... External actuator P0 ... Predetermined pressure Ps ... Predetermined value

Claims (2)

In a hydraulic pressure accumulator comprising a hydraulic pump that boosts and discharges hydraulic fluid in a reservoir, and a pressure accumulator that accumulates the discharged pressure of the hydraulic pump and supplies the accumulated hydraulic pressure to an external operating device, When the pressure of the pressure accumulator exceeds a predetermined pressure between the pressure accumulator and the external operating device, the pressure accumulator and the external operating device communicate with each other, and the pressure of the pressure accumulator is when: the predetermined pressure includes a control valve for blocking between said accumulator and said external actuator,
Pressure detecting means is provided between the pressure accumulator and the control valve, and a predetermined value higher than the predetermined pressure is set as a threshold value, and the pressure detecting means has a hydraulic pressure of the pressure accumulator equal to or lower than the threshold value. The hydraulic pressure accumulating device is characterized in that the hydraulic pump is actuated when it is detected .   The control valve includes a shut-off valve that shuts off between the pressure accumulator and the external actuator, and receives the fluid pressure of the accumulator at one end, and the shut-off when the fluid pressure of the accumulator exceeds a predetermined pressure. 2. A hydraulic pressure accumulator satisfying claim 1, further comprising a plunger for opening the valve.

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