JPS6053416A - Pressure control device for suspension bush of shock absorber - Google Patents

Abstract

PURPOSE:To restrain the attitude change of a car, with a suspension bush into which pressurized fluid can be poured, on acceleration by making the caster angle of the car smaller by means of controlling the pouring of pressurized fluid so as to shift the fixing center of the suspension bush frontward. CONSTITUTION:A suspension bush (UPPER SUPPORT) 1, which is used at the joint of a shock absorber upper end and a car body, has a ring-shaped elastic member between the outer and inner members and, in this elastic member, hollow bodies 6a and 6b are formed before and behind the fixing center of this push 1. In this case, each of the hollow bodies 6a and 6b can be connected to an oil pump 14 or a fluid reservoir 15 via a pressure control valve 10 consisting of electromagnetic direction switch valves 11 and 17, and electromagnetic open/ close valves 12 and 18. And, when the car speed is accelerated, the fixing center of the bush 1 is shifted frontward to reduce the caster angle of the car by pouring fluid into the rear hollow body 6b and taking fluid out of the front hollow body 6a.

Description

Detailed Description of the Invention (Technical Field of the Invention) The present invention relates to a suspension bushing (hereinafter referred to as This relates to a pressure control device for an upper support (also referred to as an upper support).

(Prior Art) As shown in FIGS. 1 and 2, the upper support 1 includes a ring-shaped elastic member 2, a support member 3 surrounding the ring-shaped elastic member 2 from the outside, and a connecting member 4 inserted inside the elastic member 2. It consists of Inside the elastic member 2, there are two hollow parts 5 (four if necessary) as shown in Figure 2.
) They are arranged at equal intervals in the circumferential direction, and hollow bags 6 are housed in the hollow portions 5 . The hollow bag body 6 is connected to a hose 79 via a base 7 and a 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 a piston rod of a shock absorber (not shown) is attached to this.

In FIG. 2, arrow Q indicates the direction of travel of the vehicle.

Upper support 1 installation center from 0 to tiiJ side!
! If the front body is 6a and the rear hollow body is 6b, when pressurized fluid is injected into the hollow bags 6a and 6b, the spring constant of the upper support 1 will be large, and the mounting center 0 will be at the lower position and the vehicle height will be higher. Become. Conversely, when the amount of pressurized fluid injected into the hollow bags 6a, 6b is reduced, the spring constant of the upper support 1 becomes smaller, and the height of the vehicle becomes lower when the mounting center O is raised. Furthermore, if the amount of pressurized fluid in the hollow bag body 61L is reduced and the amount of pressurized fluid in the hollow bag body 6b is increased, the installation center O will move forward and the caster angle of the vehicle will become smaller, and vice versa. Caster angle increases.

However, in the past, the amount of pressurized fluid in the hollow bag 6 was adjusted while the vehicle was stopped, and could not be adjusted while the vehicle was running.

(Objective of the Invention) This invention aims to prevent the installation center of the upper support from zero when the vehicle accelerates.
move forward to reduce the vehicle's caster angle,
The object of the present invention is to provide a pressure control device for an upper support of a shock absorber that reduces changes in the posture of a vehicle due to anti-lift of vehicle acceleration.

(Structure of the Invention) In order to achieve the above object, the present invention provides a suspension bush for a shock absorber having a front hollow bag body and a rear hollow bag body at front and rear positions, respectively, with respect to the center, a first solenoid valve, and a second solenoid valve.
a control valve having a solenoid valve, a sixth solenoid valve, and a fourth solenoid valve;
a control circuit including a throttle sensor and a speed sensor and controlling the pressure control valve, the first solenoid valve having a first port in communication with the fluid reservoir, a second port in communication with the pump, and an outlet. and has a function of communicating the second population and the outlet when energized and communicating the first population and the outlet when not energized, and the second solenoid valve is connected to the outlet of the first solenoid valve. It has a communicating inlet and an outlet communicating with the rear hollow bag body of the suspension bushing, and has the function of connecting the inlet and the outlet when energized and cutting off the communication between the inlet and the outlet (directly). death,
The fifth solenoid valve has a first port communicating with the fluid reservoir, a second port communicating with the pump, and an outlet, and when energized, the first port and the outlet are communicated, and when de-energized, the second port is connected. The fourth solenoid valve has an inlet that communicates with the outlet of the fifth solenoid valve and an outlet that communicates with the front hollow bag of the suspension bushing, and when energized, the inlet and It has the function of communicating with the outlet and cutting off the communication between the inlet and the outlet by de-energizing, and the control circuit outputs A when the rotation speed of the throttle valve is above the set value and the vehicle speed is below the set value.
When the output signal of the ND circuit is ON, it is output for a certain period of time and the first
, a first monostable circuit that energizes both the third solenoid valves, a second monostable circuit that outputs an output signal for a certain period of time when the output signal of the AND circuit is OFF, and a signal of the second monostable circuit and the first monostable circuit. and an exclusive OR circuit which inputs the circuit signal and energizes both the second and fourth solenoid valves.

(Ri (explanation by the flow side) The present invention will be explained based on drawings showing the rush side.

FIG. 6 is a block diagram of the actual flow side of this invention, in which 1 is a 7 support, 10 is a pressure control valve, 14 is a pump, 1
5 is a fluid reservoir, 16 is a throttle sensor, 60 is a speed sensor, and 20 is a control circuit.

As shown in FIG. 4, the pressure control valve 10 includes a first solenoid valve 11,
It consists of a second solenoid valve 12, a fifth solenoid valve 17, and a fourth solenoid valve 18. The first solenoid valve 11 has a first port P1 communicating with the fluid reservoir 15, a second port P2 communicating with the pump 14, and an outlet P3).
2, an inlet P4 that communicates with the outlet P3, and an outlet P5 that communicates with the rear hollow bag body 6b of the upper support 1 via a hose 9b. The communication between the inlet P4 and the outlet P5 is cut off due to the de-energization. The third solenoid valve 17 is connected to the fluid reservoir 15
It has a first population P6 communicating with the pump 14, a second population P7 communicating with the pump 14, and an outlet P8. Exit P
8 is connected. On the other hand, the fourth IIL magnetic valve 18 has an inlet P9 communicating with the outlet P8 of the sixth solenoid valve 17, and an outlet p1o communicating with the front hollow bag body 6a of the seventh support 1 via a hose 9a. Inlet P9 and outlet P when energized
10 is in communication, and communication between the two is cut off by de-energization.

Therefore, depending on the combination of energization and de-energization of the first to fourth solenoid valves, the following truth table is obtained.

- in the table is unrelated to energization or de-energization. On the other hand, the throttle sensor 1
The signal v1 of No. 6 is input to the differentiating circuit 21, and the output signal v2 of the differentiating circuit 21 and the output signal V5 of the setter 22 are input to the comparator 23, and the comparator 23 outputs when V2>V5. The output signal v4 is input to the AND circuit 29. Also, the frequency signal of the vehicle speed sensor 50 is transmitted to the F/V converter 51.
It is converted into a stain pressure signal v5. Signal v5 and setting device 3
20 signal V 6 is comparator 35! The comparator 33 outputs when 75<76, and its output signal v
7 is input to the AND circuit 29. The output signal v8 of the AND circuit 29 is input to the first monostable circuit 24 and the second monostable circuit 26. The first monostable circuit 24 outputs an output signal for a certain period of time when the output signal of the AND circuit 29 is ON, and its output signal 9 is transmitted to the first drive circuit 25, which drives the first .
The third solenoid valve 11.17 is energized. On the other hand, the second monostable circuit 26 outputs the output signal of the AND circuit 29 for a certain period of time at 077, and the output signal V1G of 7 and the output signal 9 of the first monostable circuit 24 are input to the exclusive OR circuit 27, and the same circuit 2
The output signal 711 of the second drive circuit 28 is transmitted to the second drive circuit 28, and the output signal 711 of the second drive circuit 28 is transmitted to the second drive circuit 28. The 411th magnetic valve 12°18 is energized.

A timing chart of each element of the control circuit 20 is shown in FIG. That is, FIG. 6(a) shows the output signal v1 of the throttle sensor 16, the output signal v5 of the vehicle speed sensor 30, and the output signal v6 of the setting device 62, and FIG. 6(b) shows the output signal of the differentiating circuit 21. v2 and the output signal v of the setting device 22
3 is shown in FIG. 6 (c).

) are the output signals V4 of comparators 25 and 55, respectively.
, 77 is shown. FIG. 6(e) shows the output signal v8 of the AND circuit 29, and FIG.
10 is shown. FIG. 61(a) shows the output signal V11 of the exclusive OR circuit 27. In addition, FIG. 6(s) shows the control circuit 2.
2 shows the fluctuation of the caster angle based on the fluctuation of the pressure inside the hollow bags 6a, 6b of the upper support 1 due to the pressure control valve 10 and the pressure control valve 10.

(Effects of the Invention) Since the present invention has the above-described configuration, when the accelerator pedal is being depressed at a rotational speed of the engine at a speed exceeding the set value of the 70 torque valve, that is, at a speed exceeding the set value, and when the vehicle speed is below the set value, In other words, in the case of low speed, the first. The sixth solenoid valve 11.17 is energized by the first monostable circuit 24,
The second solenoid valve 12 and the fourth solenoid valve 18 are connected to an exclusive OR circuit 27
Upper Sabo F1 is energized according to the truth table.
Fluid is injected into the rear hollow bag body 6b and the pressure increases,
Fluid is discharged from the front hollow bag 6a and the pressure drops. As a result, the attachment center 0 of the upper support 1 moves forward, and the caster angle of the vehicle becomes smaller. Then, since both the second solenoid valve 12 and the fourth solenoid valve 18 are de-energized, the truth table shows that the rear bag body 6b is sealed at high pressure, and the front bag body 6a is sealed at low pressure, so the caster angle of the vehicle body is in a small state. is maintained. As a result, the change in vehicle posture due to anti-lift during acceleration is small, and driving stability is improved. When the accelerator pedal is depressed or the vehicle speed exceeds the set value, the second solenoid valve 12 and the fourth solenoid valve 14 are energized, so that the respective inlets P4. P9 and exit P5. P10 is in communication, and since the power cylinder 1 solenoid valve 11 and the third solenoid valve 17 are not energized, in the first solenoid valve 11, the first population P1 and outlet P5 are in communication, and in the sixth solenoid valve 17, the first population is in communication. P7 and outlet P8 communicate with each other, so the six front hollow bags communicate with the pump 14, and the rear hollow bag 6b communicates with the fluid reservoir 15, so that the pressure in the front hollow bag 6a increases and the pressure in the rear hollow bag 6b increases. The pressure decreases, the attachment center O of the upper support 1 returns to its original position, and the caster angle of the vehicle also returns to its original value.

[Brief explanation of the drawing]

FIG. 1 shows a front view of the suspension bush (upper support), and FIG. 2 shows a sectional view taken along the line ■-I in FIG. FIG. 5 shows a block diagram of this invention. Figure 4 shows the pressure control valve. FIG. 5 shows the control circuit. FIG. 6 shows a timing chart of each element constituting the control circuit. 1... Suspension bush (upper support) 6a... Front hollow bag body 6b... Rear hollow bag body 10... Pressure control valve 11... First solenoid valve 12... Second solenoid valve 1
4... Pump 15... Fluid reservoir 16... Throttle sensor 17... Fifth solenoid valve 18... Fourth
Solenoid valve 20...Control circuit 23.33...Comparator 24...First monostable circuit 26...Second monostable circuit 27...Exclusive OR circuit 29...AND circuit 50...・Speed sensor applicant: Toyota Motor Corporation Representative: Patent attorney Oka 1) Hidehiko No. 1 Figure a Figure 2

Claims (1)

[Claims] A suspension bush for a four-wheel absorber having a front hollow bag body and a rear hollow bag body at front and rear positions, respectively, with respect to the center;
A pressure control valve having a first solenoid valve, a second redundant valve, a fifth solenoid valve, and a fourth solenoid valve; and a control circuit that controls the pressure control valve and includes a throttle sensor and a speed sensor;
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, with the second port in communication with the outlet when energized and the second port in communication with the pump when energized. The second electromagnetic valve has the function of communicating the first electromagnetic valve with the outlet.
has an inlet that communicates with the outlet of the valve and an outlet that communicates with the rear hollow bag of the suspension bushing, and when energized, the inlet and the outlet communicate with each other, and when not energized, the inlet and the outlet communicate with each other. The third solenoid valve has a first port in communication with the fluid reservoir, a second port in communication with the pump, and an outlet, and the third solenoid valve has a first port in communication with the fluid reservoir, a second port in communication with the pump, and an outlet; , has the function of communicating the second population and the exit without energizing, @4
The solenoid valve has an inlet that communicates with the outlet of the third solenoid valve and an outlet that communicates with the front hollow bag of the suspension bushing. The control circuit outputs an output signal for a certain period of time when the AND circuit output signal is ON when the rotation speed of the throttle valve is above the set value and the vehicle speed is below the set value. First. A first monostable circuit that energizes both the third solenoid valves, a second monostable circuit that outputs an output signal for a certain period of time when the output signal of the AND circuit is OFF, and a signal of the second monostable circuit and the first monostable circuit. and the second signal. A pressure control device for a suspension bush of a hydraulic absorber, which comprises an exclusive OR circuit that energizes both fourth solenoid valves.