JPH06307401A - Accumulator and vehicle floor height adjusting device - Google Patents

Abstract

(57) [Summary] [Purpose] To provide an accumulator capable of setting a wide pressure adjustment range. [Structure] Cylinder 51 formed in accumulator body 52
The free piston 53 is housed in the cylinder 51,
It is divided into the second chambers 54 and 55, and the accumulator main body 52 has the first
A passage 56 communicating with the chamber 54 for passing pressure oil is formed, and a disc spring 59 for pressing the free piston 53 is provided in the second chamber 55. When the pressure oil is guided to the passage 56, the disc spring 59 bends and resists the force of the pressure oil acting on the free piston 53. Therefore, when the pressure of the pressure oil is large, the amount of bending is increased to resist this. On the other hand, when the pressure of the pressure oil is small, the amount of bending is reduced to resist this, so that the pressure adjustment range can be set in a wide range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an accumulator and a vehicle height adjusting system used in a vehicle.

[0002]

2. Description of the Related Art As an example of a conventional vehicle height adjusting system, there is one proposed by the applicant in Japanese Patent Application No. 3-245069. This vehicle height adjustment system is provided with a cylinder corresponding to each wheel and a plurality of gas springs connected in parallel to the cylinder,
A switching valve having a pilot passage connected to the passage between the supply / discharge valve and the pump is provided between a plurality of gas springs, and the pressure oil generated by the pump is supplied / discharged to / from the cylinder via the supply / discharge valve. The vehicle height is adjusted by using the pilot pressure, and the spring constant is switched by using the pilot pressure to open and close the switching valve.

[0003]

However, the above-described vehicle height adjusting system has a problem that pressure pulsation occurs due to pump discharge or the like. In order to suppress this pulsation, it is conceivable to provide a gas-filled accumulator with high versatility by branching into a pipe line between the pump and the supply / discharge valve. However, in this gas-filled type accumulator, if the filling pressure is set low, desired durability cannot be obtained when the pressure of the oil liquid is high, and if the filling pressure is set high, pressure pulsation at a pressure equal to or lower than the filling pressure is generated. It cannot be absorbed. On the other hand, the vehicle height adjusting system described above has a wide pressure range of the oil liquid by switching the damping force / spring constant and adjusting the vehicle height. Therefore, the actual situation is that the above problems cannot be appropriately improved by directly applying the gas-filled accumulator to the vehicle height adjusting system described above.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an accumulator capable of setting a wide pressure adjustment range and a vehicle height adjustment system capable of properly absorbing pressure pulsation.

[0005]

In order to achieve the above-mentioned object, the invention of claim 1 stores a free piston in a cylinder formed in an accumulator body, and divides the inside of the cylinder into a first chamber and a second chamber. To form a passage in the accumulator body that communicates with the first chamber and allows the pressure oil to flow in, encloses gas in the second chamber, and multiple disc springs are coaxially arranged to press the free piston. The feature is that the directions are alternately provided. In order to achieve the above-mentioned object, the invention of claim 2 supplies pressure oil generated by a pump through a supply / discharge valve,
In a vehicle height adjusting system for performing vehicle height adjustment by supplying / discharging to / from a cylinder provided corresponding to each wheel, the accumulator according to claim 1 is provided by branching to a pipe line connecting the pump and the supply / discharge valve. It is characterized by

[0006]

According to the structure of claim 1, when the pressure oil is introduced into the passage, the disc spring bends and resists the force of the pressure oil acting on the free piston. On the other hand, when the pressure of the pressure oil is small, the amount of bending is reduced to resist this, while the amount is increased to counter this. According to the structure of claim 2, when the pressure oil is introduced into the passage of the accumulator by the pump discharge, the disc spring bends so as to resist the force of the pressure oil acting on the free piston, whereby the free piston moves toward the disc. It moves to the point where the integrated value of the spring constant of the spring and its deflection amount is in balance with the force of the pressure oil acting on the free piston.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An accumulator and a vehicle height adjusting system according to an embodiment of the present invention will be described below with reference to FIGS. In the figure, 1 is a pump driven by a motor 2, and 3a, 3b, 3c and 3d are provided corresponding to the left and right front wheels and the left and right rear wheels, respectively. These are the left and right front side cylinders and the rear side left and right cylinders that raise and lower The discharge port 1a of the pump 1 and the cylinder chambers (not shown) of the cylinders 3a, 3b, 3c, 3d are a main pipe line 5 connected to the pump 1 and front, left, right, and rear sides branched from the main pipe line 5. The left and right branch pipe lines 6a, 6b, 6c, 6d are connected to each other, and the pump 1
Is configured to suck the oil liquid 4 stored in the reservoir tank 7 to generate pressure oil and discharge the pressure oil from the discharge port 1a to the main pipe line 5.

The branch pipes 6a, 6b, 6c, 6d are provided with solenoid type supply / discharge valves 8a, 8 on the front left and right and the rear left and right.
b, 8c, 8d are interposed and passages 9a, 9b, 9c, 9
First gas springs 10a, 10b, 10c connected via d
, 10d and second gas springs 11a, 11b, 11c, 11d are provided in a branched manner. In this case, the first gas spring 10
a, 10b, 10c, 10d and the second gas springs 11a, 11b, 1
The first damping force valves 12a and 1d are respectively provided to 1c and 11d.
2b, 12c, 12d and second damping force valves 13a, 13b, 1
3c and 13d are installed respectively.

In the middle of each of the passages 9a, 9b, 9c, 9d, the front left and right and rear left and right pilot type switching valves 14a are provided.
, 14b, 14c, 14d are interposed. The pilot chambers of the pilot type switching valves 14a, 14b, 14c, and 14d are connected to the front left and right sides and upstream of the supply / discharge valves 8a, 8b, 8c, and 8d via the pilot pipe lines 15a, 15b, 15c, and 15d. It is connected to the branch lines 6a, 6b, 6c, 6d on the left and right of the rear side, and the pilot lines 15a, 15b, 15c, 15
a first gas spring 10a and a second gas spring 11a which are opened in parallel by receiving pressure oil supplied to the pilot chamber via d,
1st gas spring 10b and 2nd gas spring 11b, 1st gas spring 10c and 2nd gas spring 11c, 1st gas spring 10
d and the second gas spring 11d are communicated with each other.

A check valve 16 is provided in the main pipeline 5, a relief valve 17 is provided in the main pipeline 5 on the upstream side of the check valve 16, and the main pipeline 5 and the reservoir tank on the downstream side are provided. A solenoid type oil drain valve 18 that can be opened and closed and is normally closed is interposed between the valve 7 and 7. Front side left and right and rear side height sensors 19a, 19b, 19c are interposed between the unsprung and unsprung parts of the vehicle to detect the vehicle height and output a signal thereof.

An accumulator 50 shown in FIG. 1 is provided so as to branch to the main pipe line 5 on the downstream side of the check valve 16.
It should be noted that the left side of the center line in FIG. 1 shows a state where no pressure oil pressure is applied, and the right side of the center line shows a state where pressure oil pressure is applied. The accumulator 50 has an accumulator body 52 having a cylinder 51 formed therein. Cylinder
A free piston 53 is slidably accommodated in the cylinder 51, and the interior of the cylinder 51 is divided into first and second chambers 54 and 55. Further, a passage 56 communicating with the first chamber 54 is formed in the accumulator main body 52, and this passage 56 forms a branch passage and communicates with the main pipeline 5. The accumulator body 52 is provided with a plug 58 having a shaft portion 57, which is housed in the second chamber 55 and extends the shaft portion 57 toward the free piston 53 side.
The second chamber 55 is filled with a gas of about atmospheric pressure, and a plurality of disc springs 59 made of metal for pressing the free piston 53 are provided by alternately inserting the directions into the shaft portion 57 of the plug 58. There is.

Front side left and right and rear side height sensors
A controller 20 is provided so as to be connected to the motors 19a, 19b and 19c, the motor 2, the oil discharge valve 18 and the supply / discharge valves 8a, 8b, 8c and 8d. The controller 20 includes height sensors 19a and 19b.
, 19c to control each connected device in response to the signals from the cylinders 3a, 3b, 3c, 3d to supply and discharge the oil 4 to adjust the vehicle height, and through an interface (not shown). The oil drain valve 18 and the supply / discharge valves 8a, 8b, 8c, 8d can be freely opened / closed based on an input signal or a preset condition.

In the vehicle height adjusting system thus constructed, the pump 1 is operated and the supply / discharge valves 8a, 8b, 8c, 8d are operated to supply pressure oil to the cylinders 3a, 3b, 3c, 3d. While increasing the vehicle height, the supply / discharge valves 8a, 8b, 8c, 8d are opened and the drain oil valve 18 is opened to release the pressure oil from the cylinders 3a, 3b, 3c, 3d. Lower the height.

When the oil drain valve 18 is closed and the pump 1 is operated and the internal pressures in the pilot lines 15a, 15b, 15c, 15d exceed a predetermined value, the pilot type switching valve 14a,
14b, 14c and 14d are opened to open the first gas spring 10a and the second gas spring 11a, the first gas spring 10b and the second gas spring 11b, the first gas spring 10c and the second gas spring. 11c
, The first gas spring 10d and the second gas spring 11d communicate with each other, and the first and second gas springs 10a and 11a, the first and second gas springs 10a and 11a are connected to the cylinders 3a, 3b, 3c and 3d, respectively. Gas springs 10b, 11b, first and second gas springs 10c, 11c,
The first and second gas springs 10d and 11d function as gas springs, and the ride comfort in a soft state can be obtained.

On the other hand, when the oil discharge valve 18 is opened and the oil pressure on the upstream side of the pilot lines 15a, 15b, 15c, 15d drops below a predetermined value, the pilot type switching valves 14a, 14b.
, 14c, 14d are closed so that only the first gas springs 10a, 10b, 10c, 10d function as gas springs for the cylinders 3a, 3b, 3c, 3d, and the ride comfort in a hard state can be obtained. Become.

When the pressure oil in the main pipeline 5 is introduced into the passage 56 during the vehicle height adjustment and the spring constant adjustment described above, a force corresponding to the integrated value of the pressure of this pressure oil and the pressure receiving area of the free piston 53 is
It acts on the free piston 53. On the other hand, the disc spring 59 bends so as to resist the force of the pressure oil acting on the free piston 53,
As a result, the free piston 53 moves to a point where the integrated value of the spring constant of the disc spring 59 and the amount of deflection thereof is in balance with the force of the pressure oil acting on the free piston 53. If pressure pulsation occurs due to the discharge of pressure oil from the pump, the disc spring 59 causes the free piston to react to the force from the pressure oil.
It resists through 53 and absorbs its pressure pulsations.

Since the disc spring 59 resists the pressure of the pressure oil according to the amount of bending, when the pressure of the pressure oil is small, the amount of bending is reduced to resist it, and when the pressure of the pressure oil is large. Will increase the amount of deflection and resist this. Therefore, it is possible to properly deal with the pressure pulsation over a wide range. In a gas-filled type accumulator, when the filling pressure is increased to withstand the high pressure of the pressure oil, a sealing member may be added to improve the sealing performance, which may increase the size of the device. However, there is an accumulator 50 of this embodiment.
Then, such measures are unnecessary, and the device can be made compact accordingly. In the accumulator using the coil spring, the minimum length when contracted becomes the length corresponding to the outer diameter dimension of the coil, which is long, but in the accumulator 50 of this embodiment, the minimum length is Since the length is shortened, the size can be reduced as compared with the accumulator using the coil spring.

In the above embodiment, a plurality of disc springs are used.
By using 59 with different spring constants, it is possible to freely set the characteristics of the accumulator.

[0019]

Since the invention of claim 1 is the accumulator configured as described above, when the pressure oil is introduced into the passage, the disc spring bends and resists the force of the pressure oil acting on the free piston. Therefore, when the pressure of the pressure oil is large, the amount of deflection is increased to counter this, while when the pressure of the pressure oil is small, the amount of deflection is reduced to counter this, so the pressure adjustment range is wide. Can be set to.

Since the invention of claim 2 is the vehicle height adjusting system configured as described above, when the pressure oil is introduced into the passage of the accumulator by the pump discharge, the disc spring acts on the free piston. The free piston is bent to resist the force of the oil, whereby the free piston moves to a point where the integrated value of the spring constant of the disc spring and the amount of the flexion balances with the force of the pressure oil acting on the free piston. When it occurs, this pressure pulsation can be properly absorbed.

[Brief description of drawings]

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

FIG. 2 is a piping system diagram schematically showing a vehicle height adjusting system according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a configuration of a portion including an accumulator and its vicinity of the vehicle height adjusting system.

[Explanation of symbols]

 1 Pump 5 Main pipelines 8a, 8b Front left and right supply / discharge valves 8c, 8d Rear left / right supply / discharge valves 50 Accumulator 51 Cylinder 52 Accumulator main body 53 Free piston 54, 55 First and second chamber 56 Passage 59 Disc spring

Claims (2)

[Claims] 1. A free piston is housed in a cylinder formed in an accumulator body, and the first and second cylinders are arranged in the cylinder.
Defined in the chamber of the accumulator, a passage communicating with the first chamber is formed in the accumulator body, and a gas is enclosed in the second chamber. An accumulator characterized in that springs are provided coaxially with alternating directions. 2. A vehicle height adjusting system for adjusting the vehicle height by supplying / discharging pressure oil generated by a pump to / from a cylinder provided corresponding to each wheel through a supply / discharge valve, wherein the pump and the supply / discharge valve are provided. A vehicle height adjusting system, characterized in that the accumulator according to claim 1 is provided by branching to a pipe line that connects with.