JPS6050014A - Pressure control device in mounting bush of shock absorber - Google Patents

Abstract

PURPOSE:To prevent a change in the vehicle attitude at the time of braking so as to improve the driving stability by lifting the vehicle height by means of raising the height of an upper support of front wheel shock absorbers at the time of braking by a pressure control device for the front wheel shock absorbers of a vehicle. CONSTITUTION:When the brake oil pressure reaches a predetermined value by applying the brakes, a brake oil pressure switch 16 is turned on, and VES signal SA is outputted from a decision circuit 21 to a solenoid valve activating circuit 22 for a certain duration. Based on this, VES signal SB is outputted from a first monostable multivibration circuit 22a to activate a first solenoid valve 11. Likewise, a second solenoid valve 12 is also activated. Because of this, the oil pressure flows into a hollow vessel to increase the spring constant of a resilient member in the upper support, and so the vehicle height is lifted up. When the braking force becomes weak, the switch 16 is turned off to lower the vehicle height. Thus, the attitude change at the time of braking can be controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a pressurized fluid injectable device used in the connection between the upper end of a bump absorber attached to the front wheel side of a vehicle such as an automobile and the vehicle body. This invention relates to a pressure control device in a suspension bush.

Prior Art As shown in FIGS. 1 and 2, a suspension bush 1 (hereinafter also referred to as upper support) includes a ring-shaped elastic member 2,
It consists of a supporting member 6 fixed to surround the elastic member 2 from the outside, and a connecting member 4 fixed to the inside of the elastic member 2. There are four hollow parts 5 inside the elastic member 2.
are arranged at equal intervals in the circumferential direction, and a hollow bag body 6 is housed inside the hollow portion 5 . The hollow bag 6 is connected to a hose 9 via a 7° clamp 8, and the hose 9 communicates with a pressurized fluid source (not shown). A ball bearing 4a is attached to the connecting member 4, and the upper end of a piston rod 16 of the shock absorber is attached to this bearing 4a.

When pressurized fluid is injected into the hollow bag body 6 of this upper support 1, the volume of the hollow bag body B increases.

Therefore, the spring constant of the elastic member 2 increases and the height of the elastic member 2 increases, so the support member 6 rises and the vehicle height increases. Conversely, when the amount of pressurized fluid in the hollow bag body 6 is reduced, the spring constant of the upper support 1 becomes smaller and the vehicle height becomes lower.

However, conventionally, the amount of pressurized fluid in the hollow bag 6 has been adjusted while the vehicle is stopped, and it has been impossible to adjust the amount while the vehicle is running.

Purpose of the Invention This invention increases the vehicle height by increasing the height of the upper support of the shock absorber on the front wheel side of the vehicle, thereby creating an anti-dive effect during vehicle braking. It is an object of the present invention to provide a pressure control device for an upper support of a shock absorber, which can reduce changes in posture and improve running stability of a vehicle.

Structure of the Invention In order to achieve the above object, the structure of the present invention is as follows. That is, the pressure control valve includes a pressure control valve having a first solenoid valve and a second solenoid valve, and a control circuit that includes a brake oil pressure sensor and controls the pressure control valve. The first solenoid valve has a first port in communication with the fluid reservoir, a second port in communication with the pump, and an outlet, and when energized causes the second port to communicate with the outlet and when de-energized causes the second port to communicate with the outlet. It has a function of communicating the first population and the exit.

The second solenoid valve has an inlet that communicates with the outlet of the first solenoid valve and an outlet that communicates with the hollow bag of the upper support of the shock absorber, and when energized, the inlet and the outlet communicate with each other, It has the function of cutting off communication between the inlet and outlet by de-energizing it. The control circuit detects that the brake oil pressure has exceeded a set value and outputs a signal for a certain period of time when the output signal of the brake oil sensor is ON.
A first monostable circuit that energizes the solenoid valve, a second monostable circuit that outputs for a certain period of time when the output signal of the brake oil pressure sensor is OFF, a signal of this second monostable circuit, and a signal of the first monostable circuit. An exclusive OR that inputs and energizes the second solenoid valve.
It has a circuit.

Embodiments Next, the present invention will be explained based on embodiments shown in the drawings. Note that the same components as in FIG. 1 are given the same reference numerals and their explanations are omitted. FIG. 6 is a schematic diagram of an embodiment of the present invention, in which 1 is an upper support, 10 is a pressure control valve, 14 is an oil pump, 15 is a fluid reservoir,
16 is a brake oil pressure switch (or brake oil pressure sensor), and 20 is a control circuit.

As shown in FIG. 4, the pressure control valve 10 includes a first solenoid valve 11.
and a second solenoid valve 12. The first solenoid valve 11 has a first port P1 communicating with the fluid reservoir 15, a second port P2 communicating with the oil pump 14, and one outlet P3. This first solenoid valve 11 is energized to set the second population Pj
The communication between the first population P1 and the exit P3 is interrupted, and the first population P and the exit P3 are disconnected from each other due to the de-energization.
The communication between the second population P2 and the exit P3 is cut off. On the other hand, the second solenoid valve 12 is connected to the outlet p of the first solenoid valve 11.
It has an inlet P4 communicating with the hollow bag body B of the upper support 1 and an outlet Ps communicating with the hollow bag body B of the upper support 1 via a hose 9.

Then, the second solenoid valve 12 is energized to open the inlet P4 and the outlet P4.
5 communicate with each other, and communication between the inlet 4 and the outlet 5 is cut off due to de-energization.

'Therefore, the following truth table is obtained by combinations of energization and de-energization of the first solenoid valve 11 and the second and second solenoid valves 12.

Truth table On the other hand, in the control circuit 20 shown in FIG. Transistor T R that outputs Hl and Lo signals depending on whether it is ON or OFF
It is formed mainly from s. 22 is a solenoid valve drive circuit, which includes monostable multi-pipe lakes 22a, 22b (
(hereinafter referred to as monostable), exclusive logic circuit 22C (hereinafter referred to as EX
(referred to as OR) and amplifiers 22d and 22e. The first monostable 22a is for outputting a Hi-times signal for a predetermined time upon the rising edge of the signal SA, and the signal from now on becomes SB shown in FIG. Similarly, the second monostable 22
b outputs the H1 signal for a certain period of time in response to the fall of the signal SA, and becomes the SC shown in FIG. EXOR2
2c is the first. This is for calculating the exclusive OR of the respective signals SB and SC from the second monostables 22a and 22b, and the resulting output signal is SD shown in FIG.

1st. The second amplifications 'a22d and 22e are respectively connected to the first amplification 'a22d and 22e. To drive the second solenoid valve 11.12, the signals SB and S
The output signals SB' and SD' from the first amplifier 22d and the second amplifier 22e are the signal SB shown in FIG.
, the timing is similar to that of SD.

Next, the operation of this embodiment will be explained.

While the vehicle is running, when the driver depresses a brake pedal (not shown) and the hydraulic pressure of the brake system reaches a set value, the brake hydraulic pressure switch 16 is turned on.

As a result, the brake determination circuit 21 outputs H as shown in FIG.
An i-fold signal A is output.

This signal SAI continues while the brake oil pressure switch 16 is ON, that is, from tl to t3. Next, when the H1 signal SAI is output, the first monostable 22a is activated by the rising portion of this signal SAl to output the H1 signal SB. This signal SB is amplified by the first amplifier 22d and becomes SBf,
The first electromagnetic valve 11 is energized from time t1 to t2. On the other hand, a signal is output from the EXOR 22c and the second amplifier 22e due to the Hi-multiple signal Bt output from the first monostable 22&, and the second solenoid valve 12 is energized from time t to t2. According to the truth table, each hollow bag 6 of the upper support 1 communicates with the oil pump 14, so oil is injected and the pressure of the bag 6 increases. As a result, the elastic member 2 of the upper support 10 has a larger spring constant and expands in volume, thereby pushing the support member 3 up against the connecting member 4. Therefore, piston 07 de 13
In contrast, the vehicle body 19 side is pushed up and the vehicle height becomes higher.

When the driver weakens the pressure on the brake pedal, the oil pressure in the brake system decreases, and the brake oil pressure switch 16 turns to O.
When it becomes FF, the signal SAI of the brake judgment circuit 21 falls, so the second monostable 22b operates and the H1 signal 8
Outputs 01. This signal is connected to EXOR22c and the second
After passing through the amplifier 22e, the 21st! Since it reaches the magnetic valve 12,
The inlet P4 and outlet Ps of the second electromagnetic valve 12 communicate with each other. On the other hand, since the first electromagnetic valve 11 is not energized at this time, the first population P1 and the outlet P3 of the first electromagnetic valve 11 communicate with each other.

Therefore, each hollow bag 6 communicates with the fluid reservoir 15, the oil in the hollow bag 6 flows to the fluid reservoir 15, the oil pressure in the hollow bag 6 decreases, and the vehicle body 19 lowers.

Then, the second monostable 22b is automatically turned off after operating for a predetermined period of time, and the operation of the second solenoid valve 12 is released. The upper part of one piston red 13 returns to its normal height and maintains this state. That is, the vehicle height remains at the normal height unless the brake oil pressure switch 16 is activated.

Effects As is clear from the above explanation, according to the present invention, when the vehicle is running, when the brake is applied to brake the brake oil pressure switch, the height of the brake oil pressure switch is increased, so an anti-dive effect occurs and the safety of the vehicle is improved. It is possible to ensure running.

[Brief explanation of the drawing]

1 to 6 show an embodiment of the present invention, and the first factor is a vertical cross-sectional view (a cross-sectional view taken along line I-1 in FIG. 2) of an upper support portion of an automobile shock absorber; is I in Figure 1
- I line sectional view, Figure 6 is a block diagram of the present invention, Figure 4 is an explanatory diagram of the pressure control valve, Figure 5 is a control circuit diagram, and Figure 6 shows each component forming the control circuit in Figure 5. FIG. 3 is a diagram showing a timing chart of elements. 1... Suspension bush (upper sabot) 6... Hollow bag body 10... Pressure control valve 11... First solenoid valve 1
2...Second solenoid valve 14...Oil pump 15...
・Fluid reservoir 16... Brake oil pressure switch (brake oil pressure sensor) 20... Control circuit 24... First monostable circuit 26.
...Second monostable circuit 27...Exclusive OR circuit Applicant: Toyota Motor Corporation Agent, Patent Attorney Hidehiko Okada

Claims (1)

[Claims] A suspension bushing of a shroud absorber having an elastic member with a hollow bag body, and an eleventh! a pressure control valve having a magnetic valve and a second solenoid valve; and a control circuit including a brake oil pressure sensor and controlling the pressure control valve, the second magnetic valve having a first pressure fluid in communication with a fluid reservoir. It has a function of communicating the second population and the outlet when energized and communicating the first population and the outlet when not energized. The valve is the first
It has an inlet that communicates with the outlet of the solenoid valve and an outlet that communicates with the hollow bag body of the suspension bushing, and has a function of communicating the inlet and the outlet when energized, and cutting off communication between the inlet and the outlet when not energized. However, the control circuit turns on the output signal of the brake oil pressure sensor that is output when the brake oil pressure is higher than the set value.
a first monostable circuit that outputs for a certain period of time and energizes the first solenoid valve when the output signal of the brake oil pressure sensor is OFF; and the signal of the first monostable circuit, and the second monostable circuit is inputted.
A pressure control device in a suspension bushing of a Sikuapunba consisting of an exclusive OR circuit that energizes a solenoid valve.