JPH0451368B2 - - Google Patents

Description

[Detailed description of the invention]

(Technical Field of the Invention) This invention relates to a suspension bush (hereinafter also referred to as an atspa support) that is used to connect the upper end of a shock absorber of a vehicle such as an automobile to a vehicle body, and is capable of injecting pressurized fluid. This relates to a 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 are arranged at equal intervals in the circumferential direction as shown in FIG. There is. 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). 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. 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 reduced 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 including a throttle sensor and 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. It has 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 the communication between the inlet and the outlet when not energized. the third solenoid valve has a first inlet in communication with the fluid reservoir, a second inlet in communication with the pump, and an outlet; energization causes the first inlet to communicate with the outlet; de-energization causes the second inlet to communicate with the outlet; The fourth solenoid valve has a function of communicating the inlet and the outlet, 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 of the suspension bushing, and when energized, the inlet and the outlet are connected. The control circuit has the function of shutting off communication between the inlet and the outlet by de-energizing, and the control circuit operates for a certain period of time when the output signal of the comparator, which is output when the rotation speed of the throttle valve is higher than the set value, is ON. The first output and energize both the first and third solenoid valves.
Monostable circuit and comparator output signal are OFF
a second monostable circuit that outputs an output for a certain period of time when It is composed of. (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 fluid reservoir, 16 is a throttle 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 that communicates with the fluid reservoir 15, a second inlet P2 that communicates with the pump 14, and an outlet P3, and when energized, the second inlet P2 and the outlet P3
are in communication with each other, and the first inlet P1 and the outlet P are de-energized.
3 communicates with each other. On the other hand, the second solenoid valve 12 has an inlet P4 communicating with the outlet P3 of the first solenoid valve 11 and an outlet P5 communicating with the rear hollow bag body 6b of the Atsupa support 1 via a hose 9b. The inlet P4 and the outlet P5 communicate with each other, and the communication between the inlet P4 and the outlet P5 is cut off due to de-energization. The third solenoid valve 17 is a first inlet P that communicates with the circulation reservoir 15.
6 and a second inlet P7 and an outlet P communicating with the pump 14.
8, and when energized, the first inlet P6 and the outlet P8
are in communication, and the second inlet P7 and outlet P8 are de-energized.
communicate with. On the other hand, the fourth solenoid valve 18 has an inlet P9 that communicates with the outlet P8 of the third solenoid valve 17 and an outlet P10 that communicates with the front hollow bag body 6a of the upper support 1 via a hose 9a. P9 and outlet P10 communicate with each other, and communication between them 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 1 of the throttle sensor 16 is input to the differentiation circuit 21
The output signal V2 of the differentiator 21 and the output signal 3 of the setter 22 are input to a comparator 23, and the comparator 23 outputs when 2>3. The output signal 4 is input to a first monostable circuit 24 and a second monostable circuit 26. The first monostable circuit 24 outputs an output for a certain period of time when the output signal of the comparator 23 is ON, and the output signal V5 is transmitted to the first drive circuit 25, which drives the first solenoid valve 11 and the third solenoid valve 17. is energized. On the other hand, the second monostable circuit 2
6 outputs for a certain period of time when the output signal of the comparator 23 is OFF, the output signal 6 and the output signal 5 of the first monostable circuit 24 are input to the exclusive OR circuit 27, and the output signal 7 of the circuit 27 is input to the second The signal is transmitted to the drive circuit 28, and the second solenoid valve 1 is
2 and the fourth solenoid valve 18 are energized. A timing chart of output signals of each element of the control circuit 20 is shown in FIG. That is, FIG. 6A shows the output signal 1 of the throttle sensor 16, FIG. 6B shows the output signal 3 of the differential circuit 21, FIG. 6C shows the output signal 4 of the comparator 23, and FIG. D and E indicate the output signals of the first monostable circuit 24 and the second monostable circuit 26, respectively.
FIG. 6 shows the output signal of the exclusive OR circuit 27. In addition, FIG. 6 shows the hollow bag body 6a of the Atsupa support 1,
6b shows the variation in caster angle due to variation in pressure within 6b. (Effects of the Invention) Since the present invention has the above-described configuration, when the rotational speed is higher than the set value of the engine throttle valve, that is, while the accelerator pedal is being depressed at a speed higher than the set value, the first solenoid valve 11 and the third solenoid valve The valve 17 is energized by the first monostable circuit 24, and the second solenoid valve 12 and the fourth solenoid valve 18 are energized by the exclusive OR circuit 27, so according to the truth table, the rear hollow bag body 6b of the Atsupa support 1 Fluid is injected to increase the pressure, and fluid is discharged from the front hollow bag 6a to decrease the pressure. As a result, the attachment center O of the upper support 1 moves forward, and the caster angle of the vehicle becomes smaller. Then, the second solenoid valve 12 and the fourth solenoid valve 1
8 are both non-conducting, so according to the truth table, the rear bag 6b is sealed at high pressure, and the front bag 6a is sealed at low pressure, so the caster angle of the vehicle body is maintained at a small state. As a result, changes in vehicle posture due to anti-lift during acceleration are reduced, improving driving stability. When the depression of the accelerator pedal is finished, the second solenoid valve 12 and the fourth solenoid valve 14 are energized, so that the respective inlets P4 and P9 are connected to the outlets P5 and P10.
On the other hand, since the first solenoid valve 11 and the third solenoid valve 17 are not electrically connected, the first inlet P1 and outlet P3 of the first solenoid valve 11 communicate with each other, and the first inlet P7 of the third solenoid valve 17 communicates with each other.
The front hollow bag body 6a is connected to the pump 14, and the rear hollow bag body 6b is connected to the fluid reservoir 1.
5, the pressure in the front hollow bag body 6a increases, the pressure in the rear hollow bag body 6b decreases, and the attachment center O of the Atsupa support 1 returns to its original position, and the caster angle of the vehicle also returns to its original value. Return to

[Brief explanation of drawings]

FIG. 1 shows a front view of the suspension bush (upper support), 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... Comparator, 24... First monostable circuit, 26... Second monostable circuit, 27... Exclusive
OR circuit.

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 for controlling the pressure control valve, the first solenoid valve communicating with the first inlet communicating with the fluid reservoir and the pump. It has a second inlet and one outlet, 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, and the second solenoid valve is the first solenoid valve. and an outlet communicating with the rear 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. , the third solenoid valve has a first inlet communicating with the fluid reservoir, a second inlet communicating with the pump, and an outlet; energization causes the first inlet to communicate with the outlet, and de-energization causes the second inlet to communicate with the outlet.
The fourth solenoid valve has a function of communicating the inlet and the outlet, 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 bushing. The control circuit has the function of shutting off communication between the inlet and the outlet by de-energizing, and the control circuit operates for a certain period of time when the output signal of the comparator, which is output when the rotation speed of the throttle valve is higher than the set value, is ON. a first monostable circuit that outputs and energizes both the first and third solenoid valves; a second monostable circuit that outputs for a certain period of time when the output signal of the comparator is OFF; A pressure control device for a suspension bush of a shock absorber, comprising an exclusive OR circuit that inputs a signal from a first monostable circuit and energizes both second and fourth solenoid valves.