CN105835649A - Oil-gas suspension with volume-variable additional gas chamber and control method of oil-gas suspension - Google Patents

Abstract

The invention belongs to the technical field of automobile suspension, and relates to an oil-pneumatic suspension with a variable-volume additional air chamber and a control method thereof; The control unit, through the detection of the vehicle speed, the vertical acceleration of the vehicle body, the lateral acceleration of the vehicle, the lower cavity of the additional air chamber and the liquid pressure signal of the high-pressure oil storage tank, the electronic control unit realizes the adjustment of the hydraulic oil pressure of the additional air chamber by controlling the actuator; The hydraulic cylinder uses the energy of the vehicle vibration to generate high-pressure hydraulic oil to adjust the pressure of nitrogen in the additional air chamber, thereby adjusting the stiffness of the oil-air suspension. The additional hydraulic cylinder not only acts as a shock absorber, but also reduces energy waste; The invention has a wide range of stiffness adjustment, and at the same time, because the throttle hole has a damping effect, the car has better ride comfort, which is beneficial to improving ride comfort.

Description

A hydropneumatic suspension with variable volume additional air chamber and its control method

technical field

The invention belongs to the technical field of automobile suspension devices, and in particular relates to an oil-pneumatic suspension with a variable-volume additional air chamber and a control method thereof.

Background technique

In recent years, active oil-pneumatic suspensions have been used on some high-end cars. Active oil-pneumatic suspensions are new types of automotive suspensions that can automatically adjust the stiffness and height of suspension elastic elements. It has oil pumps that provide high-pressure oil to oil-pneumatic springs. The wheels have oil-pneumatic springs that can be individually adjusted, and are controlled by an electronic control system, which can well improve the ride comfort and handling stability of the car. At present, oil-pneumatic suspensions generally use multi-stage accumulators or additional high-pressure tanks to adjust the stiffness, but the stiffness is adjusted to a fixed value and the adjustment range is small.

The additional air chamber is generally used in the air suspension, which can adjust the stiffness and damping. The research on the volume-variable additional air chamber widens the adjustment range of the air suspension stiffness, so that the car can better adapt to different road excitations. Improve the ride comfort of the car; the application number is 201210075510.6, a variable-volume air spring additional air chamber, the invention of the additional air chamber realizes the volume change by controlling the reciprocating motion of the piston, so that the effective volume of the air spring participating in the work changes, In order to change the stiffness of the air spring system to adapt to various driving conditions of the vehicle and improve the overall performance of the suspension system, the piston of this invention must have good sealing performance; a variable volume with application number 201210544878.2 The additional air chamber of the air spring, the invention works by controlling the stepping motor, every time the central shaft rotates through a certain angle, different fan-shaped valve plates are driven to close the corresponding fan-shaped through holes, and the volume of the additional air chamber is automatically and rapidly changed, so that the air The spring obtains a large stiffness variation range, but this patent also requires good sealing, and the stepping motor needs energy consumption.

Contents of the invention

The purpose of the present invention is to realize the stiffness and damping adjustment of the oil-pneumatic suspension, and provide a kind of oil-pneumatic suspension with a variable volume additional air chamber and its control method, through the adjustable volume of the additional air chamber and the damping of the orifice function to realize the stiffness and damping adjustment of the oil-pneumatic suspension.

The technical solution of the present invention is: an oil-pneumatic suspension with a variable volume additional air chamber, including a detection mechanism, an actuator, an additional air chamber, an additional hydraulic cylinder, a high-pressure oil storage tank, an oil supply system, an oil-pneumatic suspension and electronic control unit;

The detection mechanism includes a vehicle speed sensor, a vehicle body acceleration sensor, a vehicle body lateral acceleration sensor and a liquid pressure sensor b; the actuator includes a solenoid valve a, a solenoid valve c, a solenoid valve d and an orifice;

The additional air chamber is divided into an upper chamber of the additional air chamber filled with high-pressure nitrogen gas and a lower chamber of the additional air chamber equipped with high-pressure hydraulic oil by the piston a; the liquid pressure sensor b is arranged in the lower chamber of the additional air chamber; The hydraulic cylinder is divided into the upper chamber of the additional hydraulic cylinder and the lower chamber of the additional hydraulic cylinder by the piston b; the diameter of the upper chamber of the additional hydraulic cylinder is smaller than the lower chamber of the additional hydraulic cylinder; the upper chamber of the additional hydraulic cylinder and the lower chamber of the additional hydraulic cylinder are equipped with Check valve c; the upper cavity of the additional hydraulic cylinder is communicated with the lower cavity of the additional air chamber through the hydraulic pipeline, and the lower cavity of the additional hydraulic cylinder is respectively communicated with the high-pressure oil storage tank and the lower cavity of the additional air chamber through the hydraulic pipeline; the electromagnetic Valve a is set on the hydraulic pipeline between the high-pressure oil storage tank and the lower cavity of the additional air chamber; the solenoid valve c and solenoid valve d are sequentially set on the hydraulic line between the lower cavity of the additional hydraulic cylinder and the high-pressure oil storage tank On the hydraulic pipeline; the hydraulic pipeline between the solenoid valve d and the lower chamber of the additional hydraulic cylinder is provided with a one-way valve b; the high-pressure oil storage tank is connected to the oil supply system through the hydraulic pipeline; the oil supply system and the electronic control unit electrical connection;

The upper chamber of the accumulator of the oil-pneumatic suspension is connected with the upper chamber of the additional air chamber through a pneumatic pipeline; the throttle hole is located on the air pressure pipeline between the upper chamber of the additional air chamber and the upper chamber of the accumulator;

The electronic control unit includes an input module, an operation module, a solenoid valve control module, a damper control module and an output module; the input module is electrically connected to the detection mechanism and is used to receive the vehicle speed signal of the vehicle speed sensor, the vehicle body acceleration The vertical acceleration signal of the sensor, the lateral acceleration signal of the body lateral acceleration sensor and the liquid pressure signal of the hydraulic pressure sensor b are sent to the calculation module, and the calculation module calculates the required stiffness of the suspension according to the vehicle speed signal, vertical acceleration signal and lateral acceleration signal and damping, judging whether the pressure of nitrogen in the upper cavity of the additional air chamber meets the stiffness requirement according to the liquid pressure signal, and transmitting the calculation result to the solenoid valve control module and the damper control module, the solenoid valve control module and the damper control module Generate control instructions respectively, and transmit the control instructions to the output module, the output module is electrically connected to the actuator, and the output module controls the solenoid valve a, solenoid valve c and solenoid valve d according to the instructions generated by the solenoid valve control module The switch of the throttle hole is controlled by the output module according to the instruction generated by the damper control module.

In the above solution, the oil supply system includes a hydraulic pump and an oil tank; the actuator also includes a solenoid valve b; the detection mechanism also includes a liquid pressure sensor a; the electronic control unit also includes a hydraulic pump control module;

One end of the hydraulic pump is connected to the high-pressure oil storage tank, and the other end is connected to the oil tank; the hydraulic pipeline between the hydraulic pump and the high-pressure oil storage tank is provided with a check valve a, and the liquid pressure sensor a is located at Inside the high pressure storage tank;

The electromagnetic valve b is arranged on the hydraulic pipeline between the high-pressure oil storage tank and the oil tank;

The liquid pressure sensor a is used to detect the pressure of the hydraulic oil in the high-pressure oil storage tank; the liquid pressure sensor a is electrically connected to the input module, and receives the liquid pressure signal, and sends it to the calculation module. The liquid pressure signal judges whether the pressure in the high-pressure oil storage tank meets the requirements, and transmits the calculation result to the hydraulic pump control module, and the hydraulic pump control module generates a control command, and transmits the control command to the output module, and the output The module controls the switch of the hydraulic pump according to the command.

Further, a relief valve is also included; one end of the relief valve is connected to the hydraulic pipeline between the hydraulic pump and the one-way valve a, and the other end is connected to the oil tank.

In the above solution, the solenoid valve a, solenoid valve b and solenoid valve c are all two-position two-way solenoid valves.

In the above solution, the solenoid valve d is a two-position three-way solenoid valve.

A control method according to the hydropneumatic suspension with variable volume additional air chamber, comprising the following steps:

S1. The vehicle speed sensor detects the vehicle speed signal of the vehicle body in real time, the vehicle body acceleration sensor detects the vertical acceleration signal of the vehicle, the vehicle body lateral acceleration sensor detects the vehicle’s lateral acceleration signal, and the hydraulic pressure sensor b detects the liquid pressure signal of the lower cavity of the additional air chamber. The input module of the electronic control unit receives the detected data and sends it to the computing module;

S2. The calculation module calculates the required stiffness and damping of the suspension according to the vehicle speed signal, vertical acceleration signal and lateral acceleration signal, judges whether the pressure of nitrogen in the upper chamber of the additional air chamber meets the stiffness requirement according to the liquid pressure signal, and transmits the calculation result to the solenoid valve control module and the damper control module;

S3. When the vehicle needs less rigidity, the damper control module generates a control command and transmits the control command to the output module. The output module controls the opening of the throttle hole, and the upper cavity of the additional air chamber and the upper cavity of the accumulator conduction, so that the volume of the gas increases and the stiffness of the suspension decreases; at the same time, because there is a pressure difference between the accumulator and the additional air chamber when the vehicle vibrates, the electronic control unit controls the aperture of the orifice to make the additional air chamber and the additional air chamber Proper damping between accumulators;

S4. When it is necessary to obtain greater rigidity, the command generated by the solenoid valve control module controls solenoid valve a to be energized and turned on, and when solenoid valve c is energized to close, piston b moves upward due to the vibration of the vehicle body, and the high-pressure oil storage tank and the additional The oil hole in the lower cavity of the hydraulic cylinder is closed, and the hydraulic oil in the lower cavity of the additional hydraulic cylinder is pressed into the upper cavity of the additional hydraulic cylinder; when the piston b descends, the oil circuit between the high-pressure oil storage tank and the lower cavity of the additional hydraulic cylinder is connected, and the high pressure The high-pressure hydraulic oil in the oil storage tank flows into the lower cavity of the additional hydraulic cylinder to compensate the hydraulic oil in the lower cavity of the additional hydraulic cylinder, the volume and pressure of the hydraulic oil in the lower cavity of the additional air chamber also increase accordingly, and the The nitrogen volume decreases and the pressure increases, which increases the rigidity of the oil-pneumatic suspension;

S5. When the stiffness needs to be reduced, the command generated by the solenoid valve control module controls the solenoid valve a to close, the solenoid valve c to conduct, and the solenoid valve d to the left. , at this moment, the pressure of hydraulic oil in the lower chamber of the additional air chamber decreases, the volume of nitrogen in the upper chamber of the additional air chamber increases, the pressure decreases, and the stiffness of the oil-air suspension decreases.

In the above scheme, a damping step is also included, and the damping step is specifically:

During the running of the car, the solenoid valve a and solenoid valve b are initially in the closed state, the solenoid valve c is in the conduction state, and the solenoid valve d is in the right-hand state; when the car vibrates and the body of the car goes down, the piston b moves upward , the hydraulic oil in the lower cavity of the additional hydraulic cylinder is pressed into the upper cavity of the additional hydraulic cylinder, and the high-pressure oil enters the lower cavity of the additional air chamber through the hydraulic pipeline; The pressure decreases, and the hydraulic oil returns from the lower cavity of the additional hydraulic cylinder to the upper cavity of the additional hydraulic cylinder. At this time, the additional hydraulic cylinder acts as a shock absorber to reduce the vibration of the vehicle body.

In the above solution, the oil supply step during stiffness adjustment is also included; the oil supply step is specifically: when the pressure in the high-pressure oil storage tank is lower than the set value, the hydraulic pump control module generates a control command and transmits the control command to An output module, the output module controls the operation of the oil supply system according to the instruction, so that the pressure of the liquid in the high-pressure oil storage tank reaches the required value.

In the above solution, an oil discharge step during stiffness adjustment is also included; the oil discharge step is specifically: when the pressure signal of the liquid pressure sensor a in the high-pressure oil storage tank is greater than the set value, the solenoid valve control module generates a control command, And transmit the control instruction to the output module, and when the output module controls the conduction of the solenoid valve b according to the instruction, the hydraulic oil in the high-pressure oil storage tank flows back to the oil tank.

The beneficial effects of the present invention are: compared with the prior art, the present invention adds an additional hydraulic cylinder, which plays a shock absorbing role, improves the shock absorbing performance of the automobile, and is conducive to improving the ride comfort and the smoothness of the automobile ;By adding additional air chambers and orifices, the adjustment range of stiffness and damping of the oil-pneumatic suspension is widened. The road surface excitation improves the stability of the vehicle body; since the energy of the vibration of the vehicle body is used for pressure regulation, no additional energy supply is required, which is beneficial to the energy saving of the vehicle and reduces energy waste; since the lower cavity of the additional air chamber is hydraulic oil, the additional The upper and lower chambers of the air chamber can be well separated without considering the sealing of the piston, which makes the manufacture simple; the electronic control unit is realized on the basis of the automobile suspension control unit, and no additional The electronic control unit helps to reduce the cost.

Description of drawings

Fig. 1 is a schematic structural view of an embodiment of the present invention;

Fig. 2 is a schematic structural diagram of an additional air chamber and an additional hydraulic cylinder according to an embodiment of the present invention;

Fig. 3 is a schematic diagram of electronic control according to an embodiment of the present invention;

Fig. 4 is a hydraulic oil circulation route diagram according to an embodiment of the present invention;

Fig. 5 is a flow diagram of hydraulic oil when oil is pressured into the additional air chamber according to an embodiment of the present invention;

Fig. 6 is a flow diagram of hydraulic oil when the additional air chamber discharges oil according to an embodiment of the present invention.

In the figure, 1. electronic control unit; 2. vehicle speed sensor; 3. vehicle body acceleration sensor; 4. vehicle body lateral acceleration sensor; 7. Additional hydraulic cylinder; 701. Piston push rod; 702. Piston b; 703. Lower chamber of additional hydraulic cylinder; 704. One-way valve c; 705. Upper chamber of additional hydraulic cylinder; 8. Solenoid valve a ;9, overflow valve; 10, hydraulic pump; 11, oil tank; 12, one-way valve a; 13, solenoid valve b; 14, high-pressure oil storage tank; 15, liquid pressure sensor a; 16, one-way valve b; 17. Solenoid valve d; 18. Solenoid valve c; 19. Liquid pressure sensor b; 20. Additional air chamber; 2001. Upper chamber of additional air chamber; 2002. Piston a; 2003 Lower chamber of additional air chamber.

detailed description

The present invention will be described in further detail below in conjunction with the specific embodiments of the accompanying drawings, but the protection scope of the present invention is not limited thereto.

Fig. 1 shows an embodiment of the oil-pneumatic suspension with variable volume additional air chamber of the present invention, said oil-pneumatic suspension with variable volume additional air chamber includes detection mechanism, actuator, additional air Chamber 20, additional hydraulic cylinder 7, high-pressure oil storage tank 14, oil supply system, oil-pneumatic suspension 6 and electronic control unit 1.

Figure 2 is a schematic diagram of the structure of the additional air chamber and the additional hydraulic cylinder. The additional air chamber 20 is divided into the upper chamber 2001 of the additional air chamber and the lower chamber 2003 of the additional air chamber by the piston a2002; the upper chamber 2001 of the additional air chamber is filled with high-pressure nitrogen , The lower chamber 2003 of the additional air chamber is equipped with high-pressure hydraulic oil; the lower chamber 2003 of the additional air chamber is provided with a liquid pressure sensor b19.

The additional hydraulic cylinder 7 is divided into an additional hydraulic cylinder upper cavity 705 and an additional hydraulic cylinder lower cavity 703 by the piston b702; the diameter of the additional hydraulic cylinder upper cavity 705 is smaller than the additional hydraulic cylinder lower cavity 703, so that the additional hydraulic cylinder upper cavity 705 generates high pressure Hydraulic oil; a check valve c704 is installed between the additional hydraulic cylinder upper cavity 705 and the additional hydraulic cylinder lower cavity 703, so that the hydraulic oil can only enter the additional hydraulic cylinder upper cavity 705 through the additional hydraulic cylinder lower cavity 703, preventing the hydraulic oil from Return to the lower cavity 703 of the additional hydraulic cylinder; the upper end of the additional hydraulic cylinder 7 is installed on the vehicle body, and the end of the piston push rod 701 is installed on the axle; the upper cavity 705 of the additional hydraulic cylinder passes through the hydraulic pipeline and the additional air chamber The lower chamber 2003 communicates, and the lower chamber 703 of the additional hydraulic cylinder communicates with the high-pressure oil storage tank 14 and the lower chamber 2003 of the additional air chamber respectively through hydraulic pipelines.

The hydraulic pipeline between the high-pressure oil storage tank 14 and the lower chamber 2003 of the additional air chamber is provided with a solenoid valve a8; Valve c18 and solenoid valve d17; a check valve b16 is provided on the hydraulic pipeline between the solenoid valve d17 and the lower cavity 703 of the additional hydraulic cylinder, and the check valve b16 prevents the hydraulic oil in the lower cavity 703 of the additional hydraulic cylinder from entering through the solenoid valve The lower chamber of the additional air chamber 2003; the high-pressure oil storage tank 14 is connected with the oil supply system through a hydraulic pipeline. Preferably, the solenoid valve a8 and the solenoid valve c18 are two-position two-way solenoid valves; the solenoid valve d17 is two-position three-way solenoid valves. The solenoid valve a8 is in a normally closed state. After the electricity is turned on, the high-pressure hydraulic oil in the high-pressure oil storage tank 14 flows into the lower cavity 703 of the additional hydraulic cylinder. When the vehicle body vibrates, the hydraulic oil in the lower cavity 703 of the additional hydraulic cylinder passes through the check valve. c704 enters the upper cavity 705 of the additional hydraulic cylinder and the lower cavity 2003 of the additional air chamber. The solenoid valve c18 is in the normally open state. After the power is turned off, the hydraulic oil will be stored in the upper chamber 705 of the additional hydraulic cylinder and the lower chamber 2003 of the additional air chamber. The volume decreases and the pressure increases; when the solenoid valve d17 is in the right-hand state, the hydraulic oil in the lower chamber 2003 of the additional air chamber flows into the lower chamber 703 of the additional hydraulic cylinder, and when the solenoid valve d17 is in the left-hand state, the hydraulic oil in the lower chamber 2003 of the additional air chamber Flow into the high pressure storage tank 14.

The oil supply system includes a hydraulic pump 10, an oil tank 11 and an overflow valve 9; one end of the hydraulic pump 10 is connected to the high-pressure oil storage tank 14, and the other end is connected to the oil tank 11; the hydraulic pump 10 is connected to the high-pressure oil storage tank 14 The hydraulic pipeline between the oil tanks 14 is provided with a one-way valve a12, and the one-way valve a12 prevents the high-pressure oil in the high-pressure oil storage tank 14 from flowing back into the oil tank 11; the liquid pressure sensor a15) is located in the high-pressure oil storage tank 14 . The solenoid valve b13 is provided on the hydraulic pipeline between the high-pressure oil storage tank 14 and the oil tank 11 , preferably, the solenoid valve b13 is a two-position two-way solenoid valve. The solenoid valve b13 is in a normally closed state. After being energized and turned on, the high-pressure hydraulic oil in the high-pressure oil storage tank 14 flows back into the oil tank 11 .

One end of the overflow valve 9 is connected to the hydraulic pipeline between the hydraulic pump 10 and the one-way valve a12 , and the other end is connected to the oil tank 11 . When the hydraulic oil between the hydraulic pump 10 and the one-way valve a12 is too much, it will flow back into the oil tank 11 through the overflow valve 9 to protect the hydraulic pump 10 .

The oil-pneumatic suspension 6 includes an accumulator, and the accumulator is divided into an upper accumulator cavity 601 and a lower accumulator cavity 602 by a piston; the upper accumulator cavity 601 is filled with high-pressure nitrogen, and the lower accumulator cavity 602 Equipped with high pressure hydraulic oil. The upper chamber 601 of the accumulator of the oil-pneumatic suspension communicates with the upper chamber 2001 of the additional air chamber through a pneumatic pipeline; the throttle hole 5 is located on the air pressure pipeline between the upper chamber 2001 of the additional air chamber and the upper chamber 601 of the accumulator. The flow of high-pressure gas in the upper chamber 2001 of the additional air chamber and the upper chamber 601 of the accumulator is controlled by adjusting the diameter of the throttle hole 5 , and plays a damping role.

FIG. 3 is a schematic diagram of electronic control. The detection mechanism includes a vehicle speed sensor 2 , a vehicle body acceleration sensor 3 , a vehicle body lateral acceleration sensor 4 , a fluid pressure sensor a15 and a fluid pressure sensor b19 . The vehicle speed sensor 2 mainly detects the speed of the vehicle, the vehicle body acceleration sensor 3 mainly detects the vertical acceleration of the vehicle body, the vehicle body lateral acceleration sensor 4 mainly detects the lateral acceleration of the vehicle body, and the hydraulic pressure sensor b19 is used to detect The pressure of the hydraulic oil, the liquid pressure sensor a15 is used to detect the pressure of the hydraulic oil in the high-pressure oil storage tank 14 . The actuator includes a solenoid valve a8 , a solenoid valve b13 , a solenoid valve c18 , a solenoid valve d17 , an orifice 5 and a hydraulic pump 10 . The electronic control unit 1 includes an input module, an operation module, a solenoid valve control module, a hydraulic pump control module, a damper control module and an output module; the input module is electrically connected to the detection mechanism and is used to receive the vehicle speed sensor 2, the vertical acceleration signal of the vehicle body acceleration sensor 3, the lateral acceleration signal of the vehicle body lateral acceleration sensor 4, and the fluid pressure signals of the fluid pressure sensor b19 and the fluid pressure sensor a15, and send them to the calculation module, and the calculation module according to the vehicle speed signal, vertical acceleration signal and lateral acceleration signal to calculate the required stiffness and damping of the suspension, and the operation module judges whether the pressure of nitrogen in the upper chamber 2001 of the additional air chamber meets the stiffness requirement according to the liquid pressure signal of the hydraulic pressure sensor b19, and calculates the The result is sent to the solenoid valve control module, the solenoid valve control module generates a control instruction, and sends the control instruction to the output module, the output module is electrically connected to the actuator, and the output module controls the solenoid valve a8, The switch of solenoid valve c18 and solenoid valve d17; the calculation module determines whether the pressure of the hydraulic oil in the high-pressure oil storage tank 14 meets the requirements according to the liquid pressure signal of the liquid pressure sensor a15, and transmits the calculation result to the hydraulic pump control module , the hydraulic pump control module generates a control instruction, and transmits the control instruction to the output module, and the output module controls the switch of the hydraulic pump 10 according to the instruction; the calculation module calculates the required damping of the suspension according to the signal of the detection mechanism, and sends The calculation result is sent to the damper control module, the damper control module generates a control instruction, and sends the control instruction to the output module, and the output module controls the opening and closing of the orifice 5 according to the instruction.

A control method according to the above-mentioned hydropneumatic suspension with variable volume additional air chamber, comprising the following steps:

S1, the vehicle speed sensor 2 detects the vehicle speed signal of the vehicle body in real time, the vehicle body acceleration sensor 3 detects the vertical acceleration signal of the vehicle, the vehicle body lateral acceleration sensor 4 detects the lateral acceleration signal of the vehicle, and the hydraulic pressure sensor b19 detects the liquid in the lower chamber 2003 of the additional air chamber Pressure signal, the input module of the electronic control unit 1 receives the detected data and transmits it to the computing module;

S2. The calculation module calculates the required stiffness and damping of the suspension according to the vehicle speed signal, vertical acceleration signal and lateral acceleration signal, and judges whether the pressure of nitrogen in the upper chamber 2001 of the additional air chamber meets the stiffness requirement according to the liquid pressure signal, and calculates the result of the calculation transmitted to the solenoid valve control module and the damper control module;

S3. When the automobile needs less rigidity, the damper control module generates a control instruction, and transmits the control instruction to the output module, and the output module controls the opening of the throttle hole 5, and the upper chamber 2001 of the additional air chamber and the accumulator The upper cavity 601 is connected to increase the volume of the gas and reduce the stiffness of the suspension; at the same time, when the vehicle vibrates, there is a pressure difference between the accumulator and the additional air chamber, the electronic control unit controls the aperture of the orifice 5 so that Appropriate damping is produced between the additional air chamber and the accumulator;

S4. When it is necessary to obtain greater stiffness, the command generated by the solenoid valve control module controls and controls the solenoid valve a8 to be energized and turned on, and when the solenoid valve c18 is energized and closed, the piston b702 moves upward due to the vibration of the vehicle body, and the high-pressure oil storage tank 14 and The oil hole of the lower cavity 703 of the additional hydraulic cylinder is closed, and the hydraulic oil in the lower cavity 703 of the additional hydraulic cylinder is pressed into the upper cavity 701 of the additional hydraulic cylinder; The oil circuit is connected, and the high-pressure hydraulic oil in the high-pressure oil storage tank 14 flows into the lower chamber 703 of the additional hydraulic cylinder to compensate the hydraulic oil in the lower chamber 703 of the additional hydraulic cylinder, and the volume and pressure of the hydraulic oil in the lower chamber 2003 of the additional air chamber also follow The increase, the nitrogen volume in the upper chamber 2001 of the additional air chamber decreases, the pressure increases, and the rigidity of the oil-gas suspension increases;

S5. When the stiffness needs to be reduced, the command generated by the solenoid valve control module controls the solenoid valve a8 to be closed, the solenoid valve c18 is turned on, and the solenoid valve d17 is left open. When the solenoid valve d17 is on the left side, the hydraulic oil in the lower cavity 2003 of the additional air chamber will flow to the high-pressure oil storage Tank 14, now the pressure of the hydraulic oil in the lower chamber 2003 of the additional air chamber decreases, the volume of nitrogen in the upper chamber 2001 of the additional air chamber increases, the pressure decreases, and the rigidity of the oil-gas suspension decreases.

As shown in Fig. 4, also comprise damping step, described damping step is specifically:

During the running of the car, the solenoid valve a8 and the solenoid valve b13 are initially in the closed state, the solenoid valve c18 is in the conduction state, and the solenoid valve d17 is in the right-hand state; when the car vibrates and the body of the car goes down, the piston b702 moves upward , the hydraulic oil in the lower cavity 703 of the additional hydraulic cylinder is pressed into the upper cavity 705 of the additional hydraulic cylinder, and the high-pressure oil enters the lower cavity 2003 of the additional air chamber through the hydraulic pipeline; when the body is upward, the piston b702 moves downward, and the additional hydraulic cylinder The pressure of the lower chamber 703 decreases, and the hydraulic oil returns from the lower chamber 703 of the additional hydraulic cylinder to the upper chamber 705 of the additional hydraulic cylinder. At this time, the additional hydraulic cylinder 7 acts as a shock absorber to reduce the vibration of the vehicle body.

As shown in Figure 5, it also includes an oil supply step when the stiffness is adjusted; the oil supply step is specifically: when the pressure in the high-pressure oil storage tank 14 is less than the set value, the hydraulic pump control module generates a control command, and controls the The instruction is transmitted to the output module, and the output module controls the operation of the oil supply system according to the instruction, so that the pressure of the liquid in the high-pressure oil storage tank reaches a required value.

As shown in Figure 6, it also includes an oil discharge step during stiffness adjustment; the oil discharge step is specifically: when the pressure signal of the liquid pressure sensor a15 in the high pressure oil storage tank 14 is greater than the set value, the solenoid valve control module generates control command, and transmit the control command to the output module, and the output module controls the conduction of the solenoid valve b13 according to the command, and the hydraulic oil in the high-pressure oil storage tank (14) flows back to the oil tank 11.

The present invention realizes the stiffness and damping adjustment of the oil-pneumatic suspension through the adjustable volume of the additional air chamber 20 and the damping effect of the orifice 5; the present invention mainly includes a detection mechanism, an actuator, an additional air chamber 20, an additional hydraulic cylinder Frame 6, fuel tank 11 and electronic control unit 1, through the detection of vehicle speed, vehicle body vertical acceleration, vehicle lateral acceleration, additional air chamber lower chamber 2003 and the liquid pressure signal of high-pressure oil storage tank 14, electronic control unit 1 controls the actuator Realize the adjustment of the hydraulic oil pressure in the additional air chamber 20; the additional hydraulic cylinder 7 utilizes the energy when the vehicle vibrates to generate high-pressure hydraulic oil to adjust the pressure of nitrogen in the additional air chamber 20, thereby adjusting the stiffness of the oil-pneumatic suspension. The additional hydraulic cylinder 7 not only It plays the role of a shock absorber and reduces the waste of energy; the present invention has a wide range of stiffness adjustment, and at the same time, because the throttle hole 5 has a damping effect, it makes the car have better ride comfort, which is beneficial to improve ride comfort. comfort.

The described embodiment is a preferred implementation of the present invention, but the present invention is not limited to the above-mentioned implementation, without departing from the essence of the present invention, any obvious improvement, replacement or modification that those skilled in the art can make Modifications all belong to the protection scope of the present invention.

Claims (9)

1. An oil-pneumatic suspension with an additional air chamber of variable volume is characterized in that it comprises a detection mechanism, an actuator, an additional air chamber (20), an additional hydraulic cylinder (7), a high-pressure oil storage tank (14), Oil supply system, oil and gas suspension (6) and electronic control unit (1); The detection mechanism includes a vehicle speed sensor (2), a vehicle body acceleration sensor (3), a vehicle body lateral acceleration sensor (4) and a liquid pressure sensor b (19); the actuator includes a solenoid valve a (8), a solenoid valve c ( 18), solenoid valve d (17) and orifice (5); The additional air chamber (20) is divided into an additional air chamber upper chamber (2001) filled with high-pressure nitrogen gas and an additional air chamber lower chamber (2003) equipped with high-pressure hydraulic oil by the piston a (2002); the liquid pressure sensor b (19) Set in the lower cavity of the additional air chamber (2003); the additional hydraulic cylinder (7) is divided into the upper cavity of the additional hydraulic cylinder (705) and the lower cavity of the additional hydraulic cylinder (703) by the piston b (702); the additional The diameter of the upper cavity of the hydraulic cylinder (705) is smaller than that of the lower cavity of the additional hydraulic cylinder (703); a check valve c (704) is installed between the upper cavity of the additional hydraulic cylinder (705) and the lower cavity of the additional hydraulic cylinder (703); The upper cavity of the additional hydraulic cylinder (705) is communicated with the lower cavity of the additional air chamber (2003) through the hydraulic pipeline, and the lower cavity of the additional hydraulic cylinder (703) is connected with the high-pressure oil storage tank (14) and the additional air chamber through the hydraulic pipeline respectively. The lower chamber (2003) communicates; the electromagnetic valve a (8) is arranged on the hydraulic pipeline between the high-pressure oil storage tank (14) and the lower chamber (2003) of the additional air chamber; the electromagnetic valve c (18) and the solenoid valve d (17) are sequentially arranged on the hydraulic pipeline between the additional hydraulic cylinder lower cavity (703) and the high-pressure oil storage tank (14); the electromagnetic valve d (17) and the additional hydraulic cylinder lower cavity ( 703) is provided with a check valve b (16) on the hydraulic pipeline; the high-pressure oil storage tank (14) is connected to the oil supply system through the hydraulic pipeline; the oil supply system is electrically connected to the electronic control unit (1); The upper chamber (601) of the accumulator of the oil-pneumatic suspension (6) is connected with the upper chamber (2001) of the additional air chamber through a pneumatic pipeline; the orifice (5) is located between the upper chamber (2001) of the additional air chamber On the air pressure pipeline between the upper chamber (601) of the energy device; The electronic control unit (1) includes an input module, an operation module, a solenoid valve control module, a damper control module and an output module; the input module is electrically connected to the detection mechanism and is used to receive the vehicle speed sensor (2) The vehicle speed signal, the vertical acceleration signal of the vehicle body acceleration sensor (3), the lateral acceleration signal of the vehicle body lateral acceleration sensor (4) and the liquid pressure signal of the hydraulic pressure sensor b (19) are sent to the calculation module, and the calculation module is based on the vehicle speed signal , vertical acceleration signal and lateral acceleration signal to calculate the stiffness and damping required by the suspension, judge whether the pressure of nitrogen in the upper chamber of the additional air chamber (2001) meets the stiffness requirement according to the liquid pressure signal, and transmit the calculation result to the solenoid valve control module and the damper control module, the solenoid valve control module and the damper control module respectively generate control instructions and transmit the control instructions to the output module, the output module is electrically connected to the actuator, and the output module is based on the electromagnetic The instructions generated by the valve control module control the switches of solenoid valve a (8), solenoid valve c (18) and solenoid valve d (17); the output module controls the opening of the orifice (5) according to the instructions generated by the damper control module. switch. 2. The hydropneumatic suspension with variable volume additional air chamber according to claim 1, characterized in that, the oil supply system includes a hydraulic pump (10) and an oil tank (11); the actuator also includes an electromagnetic valve b (13); the detection mechanism also includes a liquid pressure sensor a (15); the electronic control unit (1) also includes a hydraulic pump control module; One end of the hydraulic pump (10) is connected with the high-pressure oil storage tank (14), and the other end is connected with the oil tank (11); the hydraulic pipeline between the hydraulic pump (10) and the high-pressure oil storage tank (14) A one-way valve a (12) is provided, and the liquid pressure sensor a (15) is set in the high-pressure oil storage tank (14); The electromagnetic valve b (13) is arranged on the hydraulic pipeline between the high-pressure oil storage tank (14) and the oil tank (11); The liquid pressure sensor a (15) is used to detect the pressure of the hydraulic oil in the high-pressure oil storage tank (14); the liquid pressure sensor a (15) is electrically connected to the input module and receives a liquid pressure signal, and sent to the calculation module, and the calculation module judges whether the pressure in the high-pressure oil storage tank (14) meets the requirements according to the liquid pressure signal, and transmits the result of the calculation to the hydraulic pump control module, and the hydraulic pump control module generates control instructions, and The control instruction is transmitted to the output module, and the output module controls the switch of the hydraulic pump (10) according to the instruction. 3. The hydropneumatic suspension with variable volume additional air chamber according to claim 2, characterized in that, it also includes an overflow valve (9); one end of the overflow valve (9) is connected to the hydraulic pump (10) ) and the hydraulic pipeline connection between the one-way valve a (12), and the other end is connected with the oil tank (11). 4. The oil-pneumatic suspension with variable volume additional air chamber according to claim 1, characterized in that, the solenoid valve a (8), solenoid valve b (13) and solenoid valve c (18) are all Two position two way solenoid valve. 5. The oil-pneumatic suspension with an additional air chamber of variable volume according to claim 1, characterized in that the solenoid valve d (17) is a two-position three-way solenoid valve. 6. A method for controlling the hydropneumatic suspension with variable volume additional air chamber according to claim 1, characterized in that it comprises the following steps: S1, the vehicle speed sensor (2) detects the vehicle speed signal of the vehicle body in real time, the vehicle body acceleration sensor (3) detects the vertical acceleration signal of the automobile, the vehicle body lateral acceleration sensor (4) detects the lateral acceleration signal of the automobile, and the hydraulic pressure sensor b (19) Detecting the liquid pressure signal of the lower chamber of the additional air chamber (2003), the input module of the electronic control unit (1) receives the detected data and transmits it to the calculation module; S2. The calculation module calculates the required stiffness and damping of the suspension according to the vehicle speed signal, vertical acceleration signal and lateral acceleration signal, and judges whether the pressure of nitrogen in the upper cavity of the additional air chamber (2001) meets the stiffness requirement according to the liquid pressure signal, and calculates The results are transmitted to the solenoid valve control module and the damper control module; S3. When the automobile needs less rigidity, the damper control module generates a control instruction, and transmits the control instruction to the output module, and the output module controls the opening of the throttle hole (5), and the upper cavity of the additional air chamber (2001) It is connected with the upper chamber (601) of the accumulator, so that the volume of the gas increases and the stiffness of the suspension decreases; at the same time, due to the pressure difference between the accumulator and the additional air chamber when the vehicle vibrates, the electronic control unit controls the section The aperture of the orifice (5) produces suitable damping between the additional air chamber and the accumulator; S4. When it is necessary to obtain greater stiffness, the command generated by the solenoid valve control module controls and controls the solenoid valve a (8) to be energized and turned on, and when the solenoid valve c (18) is energized and closed, the piston b (702) will be caused by the vibration of the vehicle body. Moving upward, the oil holes of the high-pressure oil storage tank (14) and the lower cavity of the additional hydraulic cylinder (703) are closed, and the hydraulic oil in the lower cavity of the additional hydraulic cylinder (703) is pressed into the upper cavity of the additional hydraulic cylinder (701); the piston When b (702) goes down, the oil circuit between the high-pressure oil storage tank (14) and the lower cavity of the additional hydraulic cylinder (703) is connected, and the high-pressure hydraulic oil in the high-pressure oil storage tank (14) flows into the lower cavity of the additional hydraulic cylinder (703 ), to compensate the hydraulic oil in the lower cavity of the additional hydraulic cylinder (703), the volume and pressure of the hydraulic oil in the lower cavity of the additional air chamber (2003) also increase, the volume of nitrogen in the upper cavity of the additional air chamber (2001) decreases, and the pressure increase, so that the stiffness of the oil-pneumatic suspension increases; S5. When the stiffness needs to be reduced, the command generated by the solenoid valve control module controls the solenoid valve a (8) to close, the solenoid valve c (18) to conduct, and the solenoid valve d (17) to be left open when the additional air chamber lower chamber ( The hydraulic oil in 2003) will flow to the high-pressure oil storage tank (14). At this time, the pressure of the hydraulic oil in the lower chamber of the additional air chamber (2003) decreases, and the volume of nitrogen in the upper chamber of the additional air chamber (2001) increases and the pressure decreases. Small, the stiffness of the hydropneumatic suspension decreases. 7. The method for controlling the oil-pneumatic suspension with variable volume additional air chamber according to claim 6, further comprising a damping step, the damping step being specifically: During the running of the automobile, the solenoid valve a (8) and the solenoid valve b (13) are initially in a closed state, the solenoid valve c (18) is in a conduction state, and the solenoid valve d (17) is in a right-hand state; when the automobile vibrates When the body of the car is turned downward, the piston b (702) moves upward, the hydraulic oil in the lower chamber of the additional hydraulic cylinder (703) is pressed into the upper chamber of the additional hydraulic cylinder (705), and the high-pressure oil enters the additional air through the hydraulic pipeline. Chamber lower chamber (2003); when the vehicle body is upward, the piston b (702) moves downward, the pressure of the additional hydraulic cylinder lower chamber (703) decreases, and the hydraulic oil returns from the additional hydraulic cylinder lower chamber (703) to the additional hydraulic cylinder Cavity (705), now the additional hydraulic cylinder (7) acts as a shock absorber to reduce the vibration of the vehicle body. 8. The method for controlling the oil-pneumatic suspension with an additional air chamber with variable volume according to claim 6, further comprising an oil supply step when the stiffness is adjusted; the oil supply step is specifically: when the high-pressure oil storage When the pressure in the tank (14) is lower than the set value, the hydraulic pump control module generates a control command, and transmits the control command to the output module, and the output module controls the oil supply system to work according to the command, so that the liquid in the high-pressure oil storage tank The pressure reaches the required value. 9. The control method of the oil-pneumatic suspension with an additional air chamber with variable volume according to claim 6, characterized in that it also includes an oil discharge step when the stiffness is adjusted; the oil discharge step is specifically: when the high-pressure oil storage When the pressure signal of the liquid pressure sensor a (15) in the tank (14) is greater than the set value, the solenoid valve control module generates a control command and transmits the control command to the output module, and the output module controls the solenoid valve according to the command When b (13) is conducting, the hydraulic oil in the high-pressure oil storage tank (14) flows back to the oil tank (11).