JPH0451365B2 - - Google Patents

Description

[Detailed description of the invention]

(Technical Field of the Invention) The present invention relates to a suspension bush (hereinafter also referred to as an upper support) in which pressurized fluid can be injected, which is used for the connection between the upper part of the shock absorber of a vehicle such as an automobile and the vehicle body. This invention relates to a pressure control device. (Prior art) As shown in FIGS. 1 and 2, the Atsupa 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 is made up of. Inside the elastic member 2, two (four if necessary) hollow parts 5 as shown in FIG. ing. The hollow bag 6 is connected to a hose 9 via a cap 7 and a clamp 8, and the hose 9 communicates with a pressurized fluid source (not shown). The connecting member 4 has a ball bearing 4a.
is attached, 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. Assuming that the hollow bag in front of the attachment center O of Atsupa Support 1 is 6a, and the hollow bag behind it is 6b, when pressurized fluid is injected into the hollow bags 6a and 6b, the spring constant of Atsupa Support 1 increases, Installation center O
The position of the vehicle will be lowered and the vehicle height will be higher. On the contrary, hollow bag body 6
When the amount of pressurized fluid injected into a and 6b is reduced, the spring constant of Atsupa Support 1 becomes smaller, and the installation center O
The position of the vehicle is raised and the vehicle height is lowered. Furthermore, hollow bag body 6
If the amount of pressurized fluid in a is decreased and the amount of pressurized fluid in the hollow bag body 6b is increased, the mounting center O will move forward and the caster angle of the vehicle will become smaller, and in the opposite case, the caster angle will increase. . However, conventionally, the amount of pressurized fluid in the hollow bag 6 was adjusted while the vehicle was stopped, and it was impossible to adjust the amount while the vehicle was running. (Object of the Invention) This invention is a shock absorber that moves the mounting center O of the top support forward when the vehicle accelerates, thereby reducing the caster angle of the vehicle, thereby reducing changes in vehicle posture due to anti-lift of acceleration. The purpose is to provide a pressure control device for Atsupa Support. (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 with respect to the center, a first solenoid valve, a second solenoid valve, a control valve having a third solenoid valve and a fourth solenoid valve; and a control circuit that includes a throttle sensor and a speed sensor and controls the pressure control valve, the first solenoid valve having a first solenoid valve communicating with a fluid reservoir. It has a second inlet and one outlet that communicate with the inlet and the pump, and has a function of communicating the second inlet and the outlet when energized and communicating the first inlet and the outlet when not energized. The valve has an inlet communicating with the outlet of the first solenoid valve and an outlet communicating with the rear hollow bag of the suspension bushing, and when energized, the inlet and the outlet communicate with each other, and when de-energized, communication between the inlet and the outlet is cut off. The third solenoid valve has a first inlet that communicates with the fluid reservoir, a second inlet that communicates with the pump, and an outlet, and when energized, the first inlet and the outlet communicate with each other, and when not energized, the third solenoid valve has a first inlet communicating with the fluid reservoir, a second inlet communicating with the pump, and one outlet. The fourth 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. It has the function of communicating the inlet and outlet and cutting off the communication between the inlet and outlet by de-energizing, and the control circuit outputs an output when the rotation speed of the throttle valve is above the set value and the vehicle speed is below the set value.
A first monostable circuit that outputs for a certain period of time when the output signal of the AND circuit is ON and energizes both the first and third solenoid valves, and a second monostable circuit that outputs for a certain period of time when the output signal of the AND circuit is OFF. and an exclusive OR circuit which inputs the signal of the second monostable circuit and the signal of the first monostable circuit and energizes the second and fourth solenoid valves. (Explanation based on Examples) The present invention will be described based on drawings showing examples. FIG. 3 is a block diagram of an embodiment of the present invention, in which 1 is an upper support, 10 is a pressure control valve,
14 is a pump, 15 is a liquid reservoir, 16 is a throttle sensor, 30 is a speed sensor, and 20 is a control circuit. The pressure control valve 10 is composed of a first solenoid valve 11, a second solenoid valve 12, a third solenoid valve 17, and a fourth solenoid valve 18, as shown in FIG. First solenoid valve 11
has a first inlet P1 communicating with the liquid reservoir 15, a second inlet P2 and an outlet P3 communicating with the pump 14, the second inlet P2 and outlet P3 communicate with each other when energized, and the first inlet P2 and outlet P3 communicate with each other when not energized. Inlet P1 and outlet P3 communicate with each other. On the other hand, the second solenoid valve 12 is the first solenoid valve 11
Entrance P4 and Atsupa Support 1 that communicate with Exit P3 of
has an outlet P5 that communicates with the rear hollow bag body 6b via a hose 9b, and when energized, the inlet P4 and outlet P5 communicate, and when not energized, the inlet P4 and outlet P5 communicate with each other.
Communication with is cut off. The third solenoid valve 17 has a first inlet P6 communicating with the fluid reservoir 15 and the pump 14.
It has a second inlet P7 and an outlet P8 that communicate with each other, and when energized, the first inlet P6 and outlet P8 communicate with each other, and when not energized, the second inlet P7 and outlet P8 communicate with each other. On the other hand, the fourth solenoid valve 18 has an inlet P9 communicating with the outlet P8 of the third solenoid valve 17 and an outlet P10 communicating with the front hollow bag body 6a of the Atsupa support 1 via a hose 9a. Inlet P9 and outlet P10 communicate with each other, and communication between the two is cut off by de-energization. Therefore, the following truth table is obtained by combinations of energization and de-energization of the first to fourth solenoid valves.

[Table] - in the table is unrelated to energization or de-energization. On the other hand, in the control circuit 20 of FIG. 5, the signal V1 of the throttle sensor 16 is input to the differentiation circuit 21,
The output signal V2 of the differentiator 21 and the output signal V3 of the setter 22 are input to a comparator 23, and the comparator 23 outputs an output when V2>V3. The output signal V4 is input to the AND circuit 29. Further, the frequency signal of the vehicle speed sensor 30 is converted into a voltage signal V5 by the F/V converter 31. Signal V5 and signal of setting device 32
V6 is input to the comparator 33, which outputs when V5<V6, and its output signal V7 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 for a certain period of time when the output signal of the AND circuit 29 is ON, and the output signal V9 is transmitted to the first drive circuit 25.
17 is energized. On the other hand, the second monostable circuit 26 outputs for a certain period of time when the output signal of the AND circuit 29 is OFF, and its output signal V10 and the output signal V9 of the first monostable circuit 24 are input to the exclusive OR circuit 27, The output signal V11 is transmitted to the second drive circuit 28, and the circuit 28 drives the second and fourth solenoid valves 12,
18 is energized. A timing chart of each element of the control circuit 20 is shown in FIG. That is, FIG. 6A shows the output signal V1 of the throttle sensor 16 and the vehicle speed sensor 30.
FIG. 6B shows the output signal V2 of the differentiating circuit 21 and the output signal V3 of the setting device 22, and FIGS. output signal of
Shows V4 and V7. FIG. 6 E shows the output signal V8 of the AND circuit 29, and FIG.
Output signals of monostable circuit 24 and second monostable circuit 26
Shows V9 and V10. Figure 6-1 shows exclusive OR circuit 27
shows the output signal V11 of Incidentally, FIG. 6 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 caused by the control circuit 20 and the pressure control valve 10. (Effects of the Invention) Since the present invention has the above-described configuration, when the rotational speed of the engine throttle valve is higher than the set value, that is, the accelerator pedal is being depressed at a speed higher than the set value, and the vehicle speed is below the set value. That is, in the case of low speed, the first and third solenoid valves 11 and 17 are energized by the first monostable circuit 24, and the second solenoid valve 1 is energized by the first monostable circuit 24.
Since the 2nd and 4th solenoid valves 18 are energized by the exclusive OR circuit 27, Atsupa Support 1 is determined by the truth table.
Fluid is injected into the rear hollow bag 6b and the pressure rises, and fluid is discharged from the front hollow bag 6a and the pressure drops. As a result, the attachment center O 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 maintained in a small state. be done. As a result, changes in vehicle posture due to anti-lift during acceleration are reduced, improving driving stability.
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 communicates with outlets P5 and P10, while the first solenoid valve 1
Since the first and third solenoid valves 17 are not energized, the first inlet P1 and outlet P3 of the first solenoid valve 11 communicate with each other, and the third solenoid valve 11 communicates with the first inlet P1 and outlet P3.
In the electromagnetic valve 17, the first inlet P7 and outlet P8 communicate with each other, so the front hollow bag body 6a communicates with the pump 14, and the rear hollow bag body 6b communicates with the fluid reservoir 15.
The pressure in the front hollow bag 6a increases, the pressure in the rear hollow bag 6b 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 (attsupasapart), and FIG. 2 shows a sectional view taken along the line -- in FIG. Figure 3 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 (Atsupa support), 6a
...Front hollow bag body, 6b...Rear hollow bag body, 10
...Pressure control valve, 11...First solenoid valve, 12...
Second solenoid valve, 14...pump, 15...fluid reservoir, 16...throttle sensor, 17...third
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, 30...speed sensor.

Claims (1)

[Claims] 1. A suspension bush of 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, a second solenoid valve, and a third solenoid valve.
a pressure control valve having a solenoid valve and a fourth solenoid valve; and a control circuit including a throttle sensor and a speed sensor for controlling the pressure control valve, the first solenoid valve having a first inlet communicating with a fluid reservoir and a pump. The second solenoid valve has a function of communicating the second inlet and the outlet when energized and communicating the first inlet and the outlet when not energized. 1 having an inlet that communicates with the outlet of the solenoid valve and an outlet that communicates with the rear hollow bag 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; the third solenoid valve has a first inlet communicating with the fluid reservoir, a second inlet communicating with the pump, and an outlet, and energization causes the first inlet and the outlet to communicate;
The fourth solenoid valve has a function of communicating the second inlet and the outlet by de-energizing, and the fourth 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 body of the suspension bush; It has the function of connecting the inlet and outlet when energized, and cutting off communication between the inlet and outlet when de-energized. When the output signal of the AND circuit to output is ON, the first monostable circuit outputs for a certain period of time and energizes both the first and third solenoid valves, and the output signal of the AND circuit is OFF.
a second monostable circuit that outputs an output for a certain period of time when A pressure control device for a suspension bushing of a shock absorber.