CN113942355B

CN113942355B - Height and rigidity adjustable self-powered active suspension and working method thereof

Info

Publication number: CN113942355B
Application number: CN202111311617.1A
Authority: CN
Inventors: 吴佳睿; 王骏骋
Original assignee: Xianteng Automotive Technology Nanjing Co ltd
Current assignee: Xianteng Automotive Technology Nanjing Co ltd
Priority date: 2021-11-08
Filing date: 2021-11-08
Publication date: 2023-08-29
Anticipated expiration: 2041-11-08
Also published as: CN113942355A

Abstract

The invention discloses a self-powered active suspension with adjustable height and rigidity and a working method thereof in the field of automobiles, wherein the bottoms of cylinder bodies of a first oil cylinder and a second oil cylinder are fixedly connected, the upper part of an upper chamber of the first oil cylinder is sequentially connected with a first adjustable throttle valve, a first oil storage air chamber and the lower part of a lower chamber in series through a hydraulic pipeline, the lower end of a first spiral spring is fixedly connected with the lower end of a first piston rod, the upper end of the first spiral spring is rigidly connected with the cylinder body of the first oil cylinder, the lower spaces of the vehicle body and the second oil cylinder are provided with second spiral springs which are arranged up and down, and the hydraulic pipeline from the first oil storage air chamber to the lower part of the lower chamber of the first oil cylinder is connected with the vehicle body height and suspension rigidity-adjustable device, so that oil can be supplied to the first oil storage air chamber and the first oil cylinder and oil can flow back into the first oil cylinder; the invention adjusts the height of the vehicle body and the rigidity of the suspension in real time, improves the adaptability of the suspension to the change of the running road surface of the vehicle, and realizes the function of determining the acceleration of the sprung mass according to four parameters under the condition of not adopting the action of active control force.

Description

Height and rigidity adjustable self-powered active suspension and working method thereof

Technical Field

The invention belongs to the field of automobiles, relates to a suspension applied to automobiles, in particular to a self-powered active suspension and a working method thereof, and can effectively improve riding comfort of automobiles.

Background

The suspension is an important structure and functional part of the automobile, and has important influence on the running smoothness and the operation stability of the automobile. The suspension can be divided into a passive suspension, an active suspension and a semi-active suspension according to the working capacity of the suspension actuator. Besides the actuator, the current active suspension and semi-active suspension also need to comprise a feedback control system formed by a sensor and a controller, so that the complexity and the manufacturing cost of the system are high, and no active suspension and semi-active suspension which can be controlled in real time exist at present.

The existing passive suspension mainly adopts an elastic element, a damping element, an inertial element and the like so as to obtain better suspension comprehensive performance than the traditional passive suspension adopting the elastic element and the damping element. If an inertial member is used, the suspension typically adopts a two or more stage damping configuration. The prior common secondary vibration reduction configuration (such as literature: passive ceiling damping suspension system based on inertial volume-spring-damping structure system, agricultural machinery school report, volume 40 of 2013, 10: 1-14+9) is a traditional vibration reduction structure formed by sequentially connecting a spring element and a damping element in parallel in series between a non-sprung mass and a sprung mass and an anti-resonance vibration reduction structure formed by connecting the spring element, the damping element and the inertial volume element in parallel, although in order to further improve the working effect of the secondary vibration reduction configuration suspension, various secondary or more vibration reduction suspension configurations (such as literature: three-element inertial volume-spring anti-resonance vibration isolator vibration isolation characteristic analysis, harbin engineering university, volume 42 of 2021, 6: 766-772) appear, but the improvement of the comprehensive performance of the suspension is not obvious compared with the passive suspension adopting the traditional vibration reduction structure only. The suspension proposed in the literature of the Chinese patent application number 202110650809, named as a three-mass four-parameter adjustable secondary vibration-damping passive suspension and a working method thereof, is a suspension composed of a traditional vibration-damping structure, a suspension third mass and an anti-resonance vibration-damping structure which are connected in series from bottom to top, wherein the traditional vibration-damping structure is composed of a first oil cylinder filled with oil in an upper cavity, a first adjustable throttle valve, a second energy accumulator, a first electromagnetic valve and a first energy accumulator which are sequentially connected in series with the upper part of the upper cavity, the anti-resonance vibration-damping structure is composed of a second oil cylinder filled with oil in a lower cavity, a first inertial-volume spiral pipe, a second throttle valve, a second inertial-volume spiral pipe, a third energy accumulator, a third electromagnetic valve, a fourth energy accumulator and a second electromagnetic valve which are sequentially connected in series with the lower part of the lower cavity, and the secondary vibration-damping passive suspension has the following problems: the weight of the automobile body is sequentially transferred to the ground from the anti-resonance vibration reduction structure, the traditional vibration reduction structure and the wheels from top to bottom, namely, the weight of the automobile body is born by the hydro-pneumatic spring formed by the third energy accumulator and the second oil cylinder on the anti-resonance vibration reduction structure, and the weight of the automobile body is born by the hydro-pneumatic spring formed by the second energy accumulator and the first oil cylinder on the traditional vibration reduction structure, so that oil seals in the first oil cylinder and the second oil cylinder bear larger oil pressure difference, and the service life of the whole suspension is shorter. In addition, the compression limit of the suspension is generally designed according to a common working condition, and when an automobile runs on a bad road, the probability of being impacted is increased due to the fact that the compression stroke is increased, and then riding comfort is rapidly deteriorated.

The existing air suspension can realize height adjustment of a vehicle body, but a height sensor and a controller are needed, and the difficulty of adjusting the height in real time is high.

Disclosure of Invention

The invention aims to solve the problems that the comprehensive performance of the existing passive suspension is not obviously improved, the cost of an active suspension is high, the active suspension cannot be controlled in real time, and the difficulty in real-time adjustment of the height of a vehicle body of the existing air suspension is high.

In order to achieve the above purpose, the self-powered active suspension with adjustable height and rigidity adopts the following technical scheme: the device comprises a first oil cylinder and a second oil cylinder right above, wherein the bottoms of cylinder bodies of the first oil cylinder and the second oil cylinder are fixedly connected, the upper end piston end of a first piston rod extends into the first oil cylinder to divide the first oil cylinder into an upper sealed oil cavity and a lower sealed oil cavity which are both used for storing oil, the upper part of an upper cavity of the first oil cylinder is sequentially connected with a first adjustable throttle valve, a first oil storage air chamber and the lower part of a lower cavity in series through a hydraulic pipeline, and the lower end of the first piston rod extends downwards out of the first oil cylinder and is fixedly connected with a wheel; the space between the wheel and the upper part of the first oil cylinder is provided with a first spiral spring which is arranged up and down, the lower end of the first spiral spring is fixedly connected with the lower end of a first piston rod, and the upper end of the first spiral spring is rigidly connected with the cylinder body of the first oil cylinder; the lower end piston end of the second piston rod extends downwards in the second oil cylinder to divide the second oil cylinder into an upper sealed oil cavity and a lower sealed oil cavity which both store oil, and the upper end of the second piston rod extends upwards out of the second oil cylinder and is fixedly connected with the vehicle body; the space between the vehicle body and the lower part of the second oil cylinder is provided with a second spiral spring which is arranged up and down, the upper end of the second spiral spring is fixedly connected with the upper end and the lower end of a second piston rod, and the upper end and the lower end of the second spiral spring are rigidly connected with the cylinder body of the second oil cylinder; the hydraulic pipeline from the first oil storage air chamber to the lower part of the lower chamber of the first oil cylinder is connected with the vehicle body height and suspension rigidity adjusting device, and the vehicle body height and suspension rigidity adjusting device can supply oil to the first oil storage air chamber and the first oil cylinder and can also enable oil in the first oil storage air chamber and the first oil cylinder to flow back into the first oil storage air chamber and the first oil cylinder.

The working method of the self-powered active suspension with adjustable height and rigidity adopts the technical scheme that the working method comprises the following steps:

step A: when the automobile is stopped and the engine is not started, the height of the automobile body and the rigidity of the suspension are in the state of the lower automobile height which is initially set and the lower rigidity which is only provided by the first spiral spring, and the oil pressure in the first oil storage chamber is the same as the oil pressure in the upper oil cavity and the lower oil cavity of the first oil cylinder;

and (B) step (B): after an automobile engine is started, when the automobile is switched from a good road running mode to a bad road running mode, the device with adjustable automobile body height and suspension rigidity supplies oil, hydraulic oil flows into a first oil chamber, part of the hydraulic oil in the first oil chamber flows into an upper oil cavity of a first oil cylinder through a first adjustable flow, a first piston rod moves downwards relative to a first oil cylinder body, hydraulic oil in a lower oil cavity of the first oil cylinder flows into an upper cavity of the first oil cylinder through a first adjustable throttle valve, the first oil cylinder body moves upwards relative to the ground, and a second oil cylinder body, a second coil spring, a second piston rod and the whole automobile body move upwards relative to the ground so as to realize the lifting of the automobile body; the first coil spring and the hydro-pneumatic spring formed by the first hydro-pneumatic chamber together provide a greater stiffness;

Step C: when the automobile is switched from a bad road running mode to a good road running mode, hydraulic oil in a first oil gas chamber flows back to the device with adjustable height of the automobile body and rigidity of the suspension, the oil pressure of the first oil gas chamber is reduced, hydraulic oil in an upper oil cavity of the first oil cylinder flows to a lower oil cavity of the first oil cylinder through the first adjustable throttle valve, the first piston rod moves upwards relative to the first oil cylinder body, the first oil cylinder body moves downwards relative to the ground, the first oil cylinder body drives the second oil cylinder body, the second coil spring, the second piston rod and the automobile body to move downwards integrally relative to the ground, the automobile body is reduced, the first coil spring compresses downwards, and the first oil cylinder returns to an initial state and only provides small rigidity.

The invention has the beneficial effects after adopting the technical scheme that:

1. the self-powered active suspension of the invention is characterized in that a traditional vibration reduction structure comprising a first oil storage air chamber, a first spiral spring and a first oil cylinder and an anti-resonance vibration reduction structure comprising a second oil storage air chamber, a second spiral spring, a second oil cylinder and an inertial spiral pipe are arranged between a non-sprung mass (namely wheel mass or suspension first mass) and a sprung mass (namely vehicle body mass or suspension second mass), and when the self-powered active suspension works, the high-frequency vibration acceleration of the sprung mass is greatly reduced under the input of the same road surface unevenness; in addition, according to different driving road surface states, the height of the vehicle body and the rigidity of the suspension are adjusted in real time, and the adaptability of the suspension to the change of the driving road surface of the automobile is improved.

2. The self-powered active suspension uses the first coil spring and the second coil spring to bear the gravity of the vehicle body, and the first oil cylinder and the second oil cylinder do not need to bear the gravity of the vehicle body, so that the oil pressure difference born by the oil seals of the two oil cylinders is smaller, and the self-powered active suspension can have longer service life and better reliability than a suspension using only the hydro-pneumatic spring.

3. When the self-powered active suspension works, the acceleration of the sprung mass is simultaneously related to the relative displacement and the relative speed of the two ends of the traditional vibration reduction structure and the relative displacement and the relative speed of the two ends of the anti-resonance vibration reduction structure, and the two pairs of relative displacement and the relative speed are often used as system state vectors in system modeling. The product of the relative displacement of the two ends of the traditional vibration reduction structure and the rigidity thereof, the product of the relative speed of the two ends of the traditional vibration reduction structure and the damping thereof, the product of the relative displacement of the two ends of the anti-resonance vibration reduction structure and the rigidity thereof, and the product of the relative speed of the two ends of the anti-resonance vibration reduction structure and the damping thereof are four products, and the sum of the four products acts on the sprung mass together. In comparison, in the existing suspension, the magnitude of the sprung mass is influenced, or the sum of the products of the relative displacement and the rigidity of the two ends of the anti-resonance vibration damping structure and the products of the relative speed and the damping of the anti-resonance vibration damping structure is or the sum of the products of the relative displacement and the rigidity of the two ends of the traditional vibration damping structure and the products of the relative speed and the damping of the traditional vibration damping structure is influenced, only the sum of the two products acts on the sprung mass together, namely the acceleration of the sprung mass is related to only one pair of the relative displacement and one relative speed, and therefore, the self-powered active suspension can increase the parameter dimension influencing the rigidity and the damping from the original two dimensions to multiple dimensions (four dimensions). In addition, the sprung mass acceleration is determined by the parameters of four physical quantities, namely the suspension relative motion speed, the suspension dynamic deflection, the tire deformation speed and the tire dynamic deformation under the action of active control force, so that the self-powered active suspension still realizes the function of determining the sprung mass acceleration by the four parameters under the condition of not adopting the action of active control force.

4. When the self-powered active suspension works, the third mass of the suspension can absorb vibration energy to play a role in energy storage when the acceleration value of the third mass of the suspension is increased, and meanwhile, when the relative motion acceleration value of the anti-resonance vibration reduction structure is increased, the inertial spiral tube in the anti-resonance vibration reduction structure absorbs the vibration energy to play a role in energy storage; on the contrary, when the acceleration value of the third mass of the suspension and the relative motion acceleration value of the anti-resonance vibration reduction structure are reduced, the third mass of the suspension and the inertial spiral tube provide energy for the suspension to play a role of negative damping, so that the function of the self-powered active suspension is the same as that of the existing active suspension actuator in providing energy for the suspension under the action of an external power source, and therefore, the self-powered active suspension actuator has the advantages of simple structure, low manufacturing cost and low function of greatly reducing the high-frequency vibration acceleration of the sprung mass under the input of different road surface irregularities when the external power source is not needed.

5. According to the self-powered active suspension, the height of the vehicle body and the rigidity adjusting device of the suspension are externally connected to a working oil path of a traditional vibration reduction structure, the oil pressures in the upper oil chamber and the lower oil chamber of the first oil storage chamber and the first oil cylinder are controlled through the adjusting device, so that the vehicle is in a lower vehicle body state when the vehicle runs on a good road at a high speed, and at the moment, the rigidity of the traditional vibration reduction structure is mainly born by the first spiral spring and has lower rigidity, so that better riding comfort and better running safety are obtained; the rigidity of the traditional vibration reduction structure is provided by the parallel connection of the first spiral spring and the hydro-pneumatic spring formed by the oil-filled first oil storage air chamber, and the stiffness is high, so that the suspension rigidity is increased while the height of the vehicle body is increased, and the problem that the riding comfort is suddenly deteriorated due to the fact that the suspension is impacted in a limited manner is also avoided.

6. For four self-powered active suspensions above four wheels of an automobile, four first oil cylinders in the corresponding four traditional vibration reduction structures can be connected with a vehicle body height and suspension rigidity adjusting device through oil passages, so that each height adjusting oil cylinder in the adjusting device independently controls the respective self-powered active suspension, namely, the rigidity and the height of four single suspensions can be synchronously and accurately adjusted in real time through the same air source at lower cost. In addition, if the height-adjusting oil cylinder is provided as an oil cylinder of variable volume, multi-stage adjustment of the rigidity and height of the suspension can be achieved.

Drawings

FIG. 1 is a schematic illustration of a self-powered active suspension of adjustable height and stiffness according to the present invention;

FIG. 2 is a schematic illustration of the body height and suspension stiffness adjustable device of FIG. 1;

FIG. 3 is a schematic diagram of the operation of the self-powered active suspension of FIG. 1 with adjustable height and stiffness;

fig. 4 is a graph of the damping effect of the self-powered active suspension of the present invention.

In fig. 1: 1. a first oil reservoir plenum; 11. a first bushing; 12. a wheel; 13. a first mounting lower bracket; 14. a first coil spring; 15. a first mounting upper bracket; 16. a first piston rod; 17. a first cylinder; 18. a third mass of the suspension; 19. a spiral tube for inertial measurement; 20. a second adjustable throttle valve; 21. the second oil storage air chamber; 22. a second cylinder; 23. a second piston rod; 24. a second mounting upper bracket; 25. a second bushing; 26. a vehicle body; 27. a second coil spring; 28. a second mounting lower bracket; 29. first adjustable throttle, 30. Body height and suspension stiffness adjustable device.

In fig. 2: 2. a first electromagnetic valve; 3. a gas storage tank; 4. a one-way valve; 5. an electric air compressor unit; 6. a pressure sensor; 7. a third electromagnetic valve; 8. a controller; 9. a second electromagnetic valve; 10. and (5) height adjusting an oil cylinder.

In fig. 3: m is m ₁ The mass of the wheel 12; m is m ₂ The mass of the body 26; m is m _e Inertial volume of the anti-resonance vibration reduction structure; m is m _c The mass of the third mass 18 of the suspension; k (k) ₁ Equivalent stiffness of the wheel 12; k (k) ₂ Stiffness of the antiresonance vibration damping structure; k (k) _c Stiffness of the conventional vibration damping structure; c ₂ Damping of the antiresonance vibration damping structure; c _c Damping of the conventional vibration damping structure; q. vertical input of uneven pavement; z ₁ Vertical displacement, z, of the wheel 12 ₂ Vertical displacement of the vehicle body 26; z _c Vertical displacement of the third mass 18 of the suspension.

Detailed Description

As shown in fig. 1, the self-powered active suspension with adjustable height and rigidity according to the invention is installed between a wheel 12 and a vehicle body 26 above the wheel 12, and is a conventional vibration reduction structure and an anti-resonance vibration reduction structure which are connected in series from bottom to top, and a vehicle body height and suspension rigidity adjusting device 30 is arranged beside the conventional vibration reduction structure, and the vehicle body height and suspension rigidity adjusting device 30 is connected with the conventional vibration reduction structure through a hydraulic pipeline. The traditional vibration reduction structure is provided with a first spiral spring 14, a first oil storage air chamber 1, a first adjustable throttle valve 29 and a first oil cylinder 17, wherein the first oil cylinder 17 is arranged up and down, the upper end of a first piston rod 16 is a piston end, the piston end extends upwards in the first oil cylinder 17 to divide the first oil cylinder 17 into an upper airtight oil cavity and a lower airtight oil cavity, and oil is stored in the upper oil cavity and the lower oil cavity; the upper part of the upper chamber is sequentially connected in series with a first adjustable throttle valve 29, a first oil storage air chamber 1 and the lower part of the lower chamber through a hydraulic pipeline to form a rigidity and height adjusting oil way of the traditional vibration reduction structure. The lower end of the first piston rod 16 is a rod end, and the lower end of the first piston rod 16 extends downward outside the first cylinder 17 and is fixedly connected to the wheel 12 below through the first bush 11.

A first coil spring 14 is arranged in a space above the wheel 12 and the first oil cylinder 17, the first coil spring 14 is arranged up and down, the lower end of the first coil spring 14 is fixedly connected to the lower end of the first piston rod 16, and the upper end of the first coil spring 14 is rigidly connected with the cylinder body of the first oil cylinder 17. The best implementation structure of the invention is as follows: the method comprises the steps that a first spiral spring 14 is coaxially sleeved outside a first piston rod 16 and a cylinder body of a first oil cylinder 17, the lower end of the first spiral spring 14 is fixedly connected with the lower end of the first piston rod 16 through a first installation lower bracket 13, the first installation lower bracket 13 is fixedly sleeved outside the lower end of the first piston rod 16, and the lower end of the first spiral spring 14 is fixedly connected with the first installation lower bracket 13; the upper end of the first spiral spring 14 is fixedly connected with the lower section of the cylinder body of the first oil cylinder 17 through a first installation upper bracket 15, the first installation upper bracket 15 is fixedly sleeved outside the cylinder body of the first oil cylinder 17, and the first spiral spring 14 is fixedly connected with the first installation upper bracket 15. The central axes of the first coil spring 14, the first oil cylinder 17 and the first piston rod 16 are collinear.

The hydraulic pipeline connected to the lower part of the lower chamber of the first oil storage air chamber 1 to the lower part of the first oil cylinder 17 is connected with a vehicle body height and suspension rigidity adjusting device 30, and the vehicle body height and suspension rigidity adjusting device 30 can supply oil to the first oil storage air chamber 1 and the first oil cylinder 17 or can enable oil in the first oil storage air chamber 1 and the first oil cylinder 17 to flow back into the first oil storage air chamber, namely, can provide oil or recycle oil.

The anti-resonance vibration reduction structure is provided with a second spiral spring 27, an inertial-volume spiral pipe 19, a second adjustable throttle valve 20, a second oil storage air chamber 21 and a second oil cylinder 22, wherein the second oil cylinder 22 is arranged up and down, the lower end of a second piston rod 23 is a piston end, the piston end extends downwards in the second oil cylinder 22 to divide the second oil cylinder 22 into an upper sealed oil cavity and a lower sealed oil cavity, and oil is stored in the upper oil cavity and the lower oil cavity; the upper part of the upper chamber of the second oil cylinder 22 is sequentially connected in series with a spiral pipe 19, a second adjustable throttle valve 20, a second oil storage air chamber 21 and the lower part of the lower chamber of the second oil cylinder 22 by a hydraulic pipeline, so that a closed oil path is formed. The upper end of the second piston rod 23 is a rod end which extends upward outside the second cylinder 22 and is fixedly connected to the vehicle body 26 through a second bush 25.

A second coil spring 27 is provided in a space between the vehicle body 26 and a lower portion of the second cylinder 22, an upper end of the second coil spring 27 is fixedly connected to an upper end of the second piston rod 23, and a lower end of the second coil spring 27 is rigidly connected to a cylinder body of the second cylinder 22. The best implementation structure is as follows: the second spiral spring 27 is coaxially sleeved outside the second piston rod 23 and the second oil cylinder 22, the upper end of the second spiral spring 27 is fixedly connected to the upper end of the second piston rod 23 through a second installation upper bracket 24, the second installation upper bracket 24 is fixedly sleeved outside the second piston rod 23, and the upper end of the second spiral spring 27 is fixedly connected with the second installation upper bracket 24. The lower end of the second coil spring 27 is fixedly connected with the cylinder body of the second oil cylinder 22 through a second installation lower bracket 28, the second installation lower bracket 28 is fixedly sleeved outside the cylinder body of the second oil cylinder 22, and the lower end of the second coil spring 27 is fixedly connected with the second installation lower bracket 28. The central axes of the second coil spring 27, the second oil cylinder 22 and the second piston rod 23 are collinear.

The second oil cylinder 22 is positioned right above the first oil cylinder 17, the central axes of the two oil cylinders are collinear, and the bottoms of the two cylinder bodies are fixedly connected to form a whole after being bonded face to face up and down. The cylinder bodies of the first oil cylinder 17 and the second oil cylinder 22 are fixedly connected with a third mass 18 of a suspension, and the third mass 18 of the suspension is fixedly sleeved outside the cylinder bodies of the first oil cylinder 17 and the second oil cylinder 22 and is tightly attached to the outer wall of the cylinder body.

As shown in fig. 2, the device 30 for adjusting the height of the vehicle body and the rigidity of the suspension comprises a first electromagnetic valve 2, an oil adjusting cylinder 10, a third electromagnetic valve 7, an air storage tank 3, a one-way valve 4 and an electric air compressor unit 5 which are sequentially connected in series. The first solenoid valve 2 is a normally closed valve, the vehicle body height and suspension rigidity adjusting device 30 is connected to the first oil storage air chamber 1 and the first oil cylinder 17 through the first solenoid valve 2, the first solenoid valve 2 is connected to the cylinder outlet of the height adjusting oil cylinder 10, that is, the cylinder outlet of the height adjusting oil cylinder 10 is connected to the first oil storage air chamber 1 and the first oil cylinder 17 through the first solenoid valve 2, and is communicated through a hydraulic pipeline. A second electromagnetic valve 9 which is normally open is connected on the air path between the cylinder inlet of the height adjusting oil cylinder 10 and the third electromagnetic valve 7. And a pressure sensor 6 is externally connected on the air path between the third electromagnetic valve 7 and the one-way valve 4 and is used for detecting the air pressure at the position. The check valve 4 is used to prohibit the back flow of the compressed air to the electric air compressor package 5. The pressure sensor 6 is connected to the controller 8 through a signal line, and the controller 8 is connected to the electric air compressor unit 5, the first electromagnetic valve 2, the second electromagnetic valve 9 and the third electromagnetic valve 7 through control signal lines respectively.

As shown in fig. 1, when the vehicle is in an initial state in which the vehicle is stopped and the engine is not started, the vehicle body height and the suspension stiffness are in an initial set state of lower vehicle height and lower stiffness, that is, the vehicle body height and suspension stiffness adjustable device 30 is in an initial set state in which oil is not supplied to an oil passage between an upper cavity and a lower cavity of the first cylinder 17 of the conventional vibration damping structure, at this time, the oil pressure in the first oil storage chamber 1 and the oil pressure in upper and lower oil cavities of the first cylinder 17 are the same, balance of the suspension is maintained, and at this time, the stiffness of the conventional vibration damping structure is provided only by the first coil spring 14.

When the driver selects the good road running mode after the automobile engine is started, the state of the lower automobile body and the state of the lower rigidity which are initially set are maintained unchanged, namely, the state that the oil supply to the oil path between the upper oil cavity and the lower oil cavity of the first oil cylinder 17 with the traditional vibration reduction structure is not initially set is maintained unchanged by the automobile body height and the suspension rigidity adjustable device 30.

When the driver switches the good road running mode to the bad road running mode, the vehicle body height and suspension rigidity adjustable device 30 supplies oil to the first oil chamber 1 and the first oil cylinder 17, under the action of inertia of the vehicle body 26, hydraulic oil firstly flows into the first oil chamber 1 with a soft structure, which is compressible by air, from the vehicle body height and suspension rigidity adjustable device 30, so that the oil pressure in the first oil chamber 1 rises, part of hydraulic oil in the first oil chamber 1 flows into an upper oil cavity of the first oil cylinder 17 through the first adjustable throttle valve 29, the pressure on the upper surface and the lower surface of a piston acting on the first piston rod 16 in the first oil cylinder 17 increases, and the upper surface area of the piston is larger than the lower surface area of the piston, so that the first piston rod 16 moves downwards relative to the first oil cylinder 17, and the first piston rod 16 is fixedly connected with the wheels 12 and supported on the road surface, namely the first oil cylinder 17 moves upwards relative to the ground, and the first oil cylinder 17 drives the second oil cylinder 22, the second coil spring 27, the second piston rod 23 and the vehicle body 26 integrally move upwards relative to the ground, so that the lifting of the vehicle body 26 is realized.

At the same time of the downward movement of the first piston rod 16 relative to the body of the first cylinder 17, the volume of the lower oil chamber is reduced, and the hydraulic oil in the lower oil chamber flows through the first adjustable throttle 29 via the oil passage to the upper chamber of the first cylinder 17. Therefore, when the vehicle body height and suspension rigidity adjusting apparatus 30 supplies oil, the oil flows into the first oil chamber 1 to become a hydro-pneumatic spring, and part of the hydraulic oil in the first oil chamber 1 finally flows into the upper oil chamber of the first oil cylinder 17, and the vehicle body 26 is kept elevated together with the hydraulic oil from the lower oil chamber of the first oil cylinder 17. As the vehicle body 26 is lifted, the weight of the vehicle body 26, which is transmitted from the second piston rod 23, the second coil spring 27 and the second cylinder 22, is reduced by the first coil spring 14, and the reduced weight is received by the hydro-pneumatic spring formed by the first hydro-pneumatic chamber 1, and at this time, the stiffness of the conventional vibration damping structure is provided by the first coil spring 14 and the hydro-pneumatic spring formed by the first hydro-pneumatic chamber 1 together, and the suspension stiffness is in a state of high stiffness, so that the initial smaller stiffness is adjusted to be higher.

When the driver switches the bad road running mode to the good road running mode, the vehicle body height and suspension stiffness adjustable device 30 controls hydraulic oil in the first oil chamber 1 and the first oil cylinder 17 to flow back to the vehicle body height and suspension stiffness adjustable device 30, the hydraulic oil in the first oil chamber 1 firstly flows back to the vehicle body height and suspension stiffness adjustable device 30, so that the oil pressure in the first oil chamber 1 is reduced, the pressure on the upper and lower surfaces of the upper piston of the first piston rod 16 acting in the first oil cylinder 17 is reduced, the first piston rod 16 moves upwards relative to the cylinder body of the first oil cylinder 17, and the cylinder body of the first oil cylinder 17 moves downwards relative to the ground due to the fact that the first piston rod 16 is fixedly connected with the wheels 12, and at the moment, the cylinder body of the first oil cylinder 17 drives the cylinder body of the second oil cylinder 22, the second coil spring 27, the second piston rod 23 and the vehicle body 26 to move downwards integrally relative to the ground, so that the reduction of the vehicle body 26 is realized.

When the first piston rod 16 moves up relative to the body of the first cylinder 17, hydraulic oil in the upper oil chamber of the first cylinder 17 flows through the first adjustable throttle 29 through the oil passage and then flows to the lower oil chamber of the first cylinder 17. After hydraulic oil flows back from the first oil chamber 1 to the vehicle body height and suspension rigidity adjusting device 30, the pressure in the first oil chamber 1 is reduced to lose the function of the oil gas spring, the vehicle body 26 is reduced, the downward compression amount of the first spiral spring 14 is increased, and the hydraulic oil independently bears the gravity of the vehicle body 26 transmitted by the upper second piston rod 23, the second spiral spring 27 and the second oil cylinder 22, and at the moment, the rigidity of the traditional vibration reduction structure is only provided by the first spiral spring 14, namely, the suspension rigidity is restored to the initial smaller rigidity state.

When the vehicle is stopped and the engine is turned off, the vehicle body height and suspension stiffness adjustable device 30 automatically returns to the initial set state, i.e., the state in which oil is not supplied to the oil passage between the upper oil chamber and the lower oil chamber of the first oil cylinder 17 of the conventional vibration damping structure, so that the vehicle body height and suspension stiffness are returned to the initial set lower vehicle body and lower stiffness state.

As shown in fig. 2, when the vehicle is in an initial state in which the vehicle is stopped and the engine is not started, the vehicle body height and the suspension stiffness are in an initial set lower vehicle body and lower stiffness state, the initial state of the height-adjusting oil cylinder 10 is that the cylinder thereof is in a state of being full of hydraulic oil, the cylinder thereof is in a state of exhausting compressed air, the first electromagnetic valve 2 maintains a normally closed state, the cylinder of the height-adjusting oil cylinder 10 is blocked from supplying oil to the first cylinder 17 and the first oil storage chamber 1, the second electromagnetic valve 9 maintains a normally open state, the cylinder of the height-adjusting oil cylinder 10 is communicated with the atmosphere, the compressed air therein is exhausted, the third electromagnetic valve 7 maintains a normally closed state, and the gas flow between the gas storage tank 3 and the cylinder of the height-adjusting oil cylinder 10 is blocked.

When the automobile engine is started, the controller 8 controls the electric air compressor unit 5 to work, the electric air compressor unit 5 generates compressed air, the compressed air enters the air storage tank 3 through the one-way valve 4 to be stored, when the pressure sensor 6 detects that the pressure of the air storage tank 3 reaches a control preset value, the electric air compressor unit 5 is closed, the air storage tank 3 is stopped to be inflated, and the preparation for the work of the device 30 with the adjustable height and the adjustable suspension stiffness of the automobile is completed.

When the driver selects the good road running mode, the controller 8 maintains the normally closed state of the first electromagnetic valve opening 2, the normally open state of the second electromagnetic valve 9 and the normally closed state of the third electromagnetic valve 7 unchanged, namely, oil is not supplied to the first oil cylinder 17 and the first oil storage air chamber 1 of the traditional vibration reduction structure.

When the driver switches the automobile from a good road running mode to a bad road running mode, the controller 8 firstly controls the second electromagnetic valve 9 to be closed, cuts off the air flow between the cylinder of the height-adjusting oil cylinder 10 and the atmosphere, then controls the first electromagnetic valve 2 and the third electromagnetic valve 7 to be simultaneously opened, the opening of the first electromagnetic valve 2 opens an oil path between the cylinder of the height-adjusting oil cylinder 10 and the first oil cylinder 17 and the first oil storage air chamber 1, the opening of the third electromagnetic valve 7 enables the gas in the gas storage tank 3 to enter the cylinder of the height-adjusting oil cylinder 10, the compressed air in the gas storage tank 3 flows into the cylinder of the height-adjusting oil cylinder 10 through the third electromagnetic valve to be closed 7, and the piston of the height-adjusting oil cylinder 10 is driven to push the hydraulic oil in the cylinder of the height-adjusting oil cylinder 10 to supply oil to the traditional vibration reduction structure through the first electromagnetic valve 2. After the oil supply is completed, the controller 8 firstly controls the first electromagnetic valve 2 and the third electromagnetic valve 7 to be closed simultaneously, cuts off the gas flow between the gas storage tank 3 and the cylinder of the height-adjusting oil cylinder 10, avoids the compressed air from continuously flowing into the cylinder of the height-adjusting oil cylinder 10 from the gas storage tank 3, simultaneously cuts off the hydraulic oil flow between the oil cylinder of the height-adjusting oil cylinder 10 and the oil way between the traditional vibration reduction structure, avoids the piston in the height-adjusting oil cylinder 10 to bear the fluctuation pressure generated by the suspension work, and then, the controller 8 controls the second electromagnetic valve 9 to be opened again, so that the cylinder of the height-adjusting oil cylinder 10 is communicated with the atmosphere, and the compressed air in the cylinder of the height-adjusting oil cylinder 10 is discharged, so that the subsequent vehicle body height is reduced and the suspension rigidity is reduced. Finally, the controller 8 controls the electric air compressor unit 5 to start working again, compressed air generated by the electric air compressor unit 5 enters the air storage tank 3 through the one-way valve 4 to be stored, when the pressure sensor 6 displays that the pressure reaches a preset value, the electric air compressor unit 5 is closed, the air storage tank 3 is stopped from being inflated, and the next oil supply preparation work of the vehicle height and suspension stiffness adjustable device 30 is completed.

When a driver switches a bad road running mode to a good road running mode, the controller 8 firstly controls the first electromagnetic valve 2 to open, hydraulic oil in an oil path between the oil cylinder of the height-adjusting oil cylinder 10 and a traditional vibration reduction structure is allowed to flow, hydraulic oil in the oil path between an upper oil cavity and a lower oil cavity of the first oil cylinder 17 flows back to the oil cylinder of the height-adjusting oil cylinder 10 under the action of the gravity of a vehicle body transmitted by the second piston rod 23, the second coil spring 27 and the cylinder body of the second oil cylinder 22, and after oil return of the oil cylinder of the height-adjusting oil cylinder 10 is completed, the controller 8 controls the first electromagnetic valve 2 to close again, so that the hydraulic oil in the oil path between the oil cylinder of the height-adjusting oil cylinder 10 and the oil path between the upper oil cavity and the lower oil cavity of the first oil cylinder 17 of the traditional vibration reduction structure is cut off, and the piston in the height-adjusting oil cylinder 10 is prevented from bearing fluctuation pressure generated by suspension work.

Before the vehicle engine is shut down, the height-adjusting oil cylinder 10 may take two states, the first being a state in which hydraulic oil in its cylinder is empty and the second being a state in which its cylinder is full of oil. When the oil cylinder of the height-adjusting oil cylinder 10 is in a state of being emptied of hydraulic oil, and when the automobile is in a bad road running mode, the controller 8 firstly controls the hydraulic oil of the traditional vibration reduction structure to flow back to the oil cylinder of the height-adjusting oil cylinder 10. When the cylinder of the height-adjusting oil cylinder 10 is in a state of being full of oil, the controller 8 controls the first electromagnetic valve 2 to be closed, and to be restored to a normally closed state, and cuts off the flow of hydraulic oil between the cylinder of the height-adjusting oil cylinder 10 and the oil passage between the conventional vibration damping structures. Then, the controller 8 controls the second electromagnetic valve 9 to open again, and the normally open state is restored, so that the cylinder of the height-adjusting oil cylinder 10 is communicated with the atmosphere, and at this time, the vehicle body height and suspension rigidity adjusting device 30 is in an initial setting state.

When the vehicle is traveling on a good road, that is, in a good road traveling mode, the vehicle body is in a low state, the rigidity of the conventional vibration damping structure is provided by the first coil spring 14, and the oil passage between the upper oil chamber and the lower oil chamber of the first cylinder 17 of the conventional vibration damping structure is damped only by the first adjustable throttle 29, and therefore, the pressure acting on the upper and lower surfaces of the piston of the first piston rod 16 in the first cylinder 17 is low. When the wheel 12 starts to vibrate upwards, the vehicle body 26 does not move so far, the wheel 12 pushes the suspension third mass 18 to move upwards by compressing the first coil spring 14 and the first oil cylinder 17 upwards, so that the suspension third mass 18 generates inertia force, the suspension third mass 18 compresses the second coil spring 27 and the second oil cylinder 22 upwards when moving upwards, the vehicle body 26 is pushed to move upwards, during the movement, when the upward vibration of the wheel 12 passes through the traditional vibration reduction structure, the first mounting lower bracket 13 on the first piston rod 16 pushes the first cylinder 17 to move upwards through the first coil spring 14 by the first mounting upper bracket 15, vibration isolation is performed on the upward vibration of the wheel 12 once, meanwhile, the first piston rod 16 compresses the hydraulic oil in the upper oil cavity of the first cylinder 17 through the piston thereon, flows to the lower oil cavity of the first cylinder 17 and the first oil storage air chamber 1 through the first adjustable throttle 29, and the first adjustable throttle 29 generates damping to damp the upward vibration of the wheel 12; when the wheel 12 subjected to vibration isolation and vibration reduction by the traditional vibration reduction structure vibrates upwards and is transmitted to the cylinder body of the second oil cylinder 22 and the third mass 18 of the suspension, the third mass 18 of the suspension absorbs the upward vibration kinetic energy of the wheel 12 once; when the wheel 12, which absorbs kinetic energy after passing through the suspension third mass 18, vibrates upwards, and passes through the anti-resonance vibration reduction structure, the second mounting lower bracket 28 on the second oil cylinder 22 pushes the vehicle body 26 to move upwards through the second spiral spring 27 by the second mounting upper bracket 24, meanwhile, the second oil cylinder 22 compresses hydraulic oil in the lower cavity of the second oil cylinder 22 through the cylinder body, and the hydraulic oil flows to the upper cavity of the second oil cylinder 22 and the second oil storage air chamber 21 through the second adjustable throttle valve 20 and the inertia spiral pipe 19, damping and inertia are respectively generated by the second adjustable throttle valve 20 and the inertia spiral pipe 19, and the anti-resonance vibration reduction is carried out on the upward vibration of the wheel 12 once through the stiffness of the second spiral spring 27, so that the input of the upward vibration of the wheel 12 to the vehicle body 26 is greatly attenuated finally.

When the automobile runs on a good road, the automobile body is in a lower state, the rigidity of the traditional vibration reduction structure is mainly provided by the first spiral spring 14, the automobile body 26 does not move until the moment when the wheels 12 start to vibrate downwards, the wheels 12 drive the first spiral spring 14 downwards, the first oil cylinder 17 pulls the suspension third mass block 18 to move downwards, so that the suspension third mass block 18 generates inertia force, and the suspension third mass block 18 moves downwards to pull the second spiral spring 27 and the second oil cylinder 22 downwards to drive the automobile body 1 to move downwards; in the moving process, when the downward vibration of the wheel 12 passes through the traditional vibration reduction structure, the first mounting lower bracket 13 on the first piston rod 16 drives the first cylinder body 17 to move downwards through the first spiral spring 14 by the first mounting upper bracket 15, and vibration isolation is carried out on the downward vibration of the wheel 12 once, meanwhile, the first piston rod 16 compresses hydraulic oil in the lower cavity of the first cylinder body 17 through the piston on the first piston rod 16, and flows to the upper cavity of the first cylinder body 17 through the first adjustable throttle valve 29, and at the moment, the hydraulic oil in the first oil storage air chamber 1 flows into oil supplementing cavity on the first cylinder body 17, and damping is generated by the first adjustable throttle valve 29 to reduce the downward vibration of the wheel 12 once; when the wheel 12 vibration-isolated and vibration-reduced by the traditional vibration-reducing structure is transmitted to the second cylinder 22 and the third mass 18 of the suspension, the third mass 18 of the suspension absorbs the kinetic energy of the downward vibration of the wheel 12 once; when the wheel 12 after absorbing the kinetic energy through the suspension third mass 18 vibrates downwards, the second mounting lower bracket 28 on the second oil cylinder 22 drives the vehicle body 26 to move downwards through the second spiral spring 27 by the second mounting upper bracket 24, meanwhile, the cylinder body of the second oil cylinder 22 descends to compress hydraulic oil in an upper cavity of the second oil cylinder to flow to a lower oil cavity of the second oil cylinder 22 through the second adjustable throttle valve 20 and the inertia spiral pipe 19, at the moment, the hydraulic oil in the second oil storage air chamber 21 flows into the lower oil cavity of the second oil cylinder 22 to supplement oil, and damping and inertia capacity are respectively generated by the second adjustable throttle valve 20 and the inertia spiral pipe 19, and the damping and inertia capacity and the rigidity of the second spiral spring 27 perform one-time anti-resonance vibration on the upward vibration of the wheel 12, so that the downward vibration input of the vehicle body 26 is greatly attenuated finally.

At this time, the automobile can run at a high speed on a good road and is in a lower body state, and the rigidity of the conventional vibration damping structure is mainly provided by the first coil spring 14 to have a smaller rigidity, so that better riding comfort and better running safety are obtained.

When the automobile runs on a bad road, in a bad road running mode, the automobile body is in a higher state, the rigidity of the traditional vibration reduction structure is provided by a first spiral spring 14 and an oil-gas spring formed by an oil-filled first oil storage air chamber 1, the pressure of the upper surface and the lower surface of a piston acting on a first piston rod 16 in a first oil cylinder 17 is increased, the automobile body 26 does not move until the moment when the wheel 12 starts to vibrate upwards, the wheel 12 pushes a suspension third mass 18 to move upwards by compressing the first spiral spring 14 and the first oil cylinder 17 upwards, so that the suspension third mass 18 generates inertia force, and the suspension third mass 18 upwards compresses a second spiral spring 27 and a second oil cylinder 22 to push the automobile body 1 to move upwards; in the moving process, when the upward vibration of the wheel 12 passes through the traditional vibration reduction structure, the first mounting lower bracket 13 on the first piston rod 16 pushes the first cylinder body 17 to move upwards through the first spiral spring 14 by the first mounting upper bracket 15, meanwhile, the first piston rod 16 compresses hydraulic oil in the upper cavity of the first cylinder body 17 through the piston on the first piston rod to flow to the lower cavity of the first cylinder body 17 and the first oil storage air chamber 1 through the first adjustable throttle valve 29, the oil-gas spring formed by the oil-filled first oil storage air chamber 1 is connected with the first spiral spring 14 in parallel and performs primary vibration reduction on the upward vibration of the wheel 12, and the damping generated by the first adjustable throttle valve 29 performs primary vibration reduction on the upward vibration of the wheel 12; when the wheel 12 subjected to vibration isolation and vibration reduction by the traditional vibration reduction structure vibrates upwards and is transmitted to the cylinder body of the second oil cylinder 22 and the third mass 18 of the suspension, the third mass 18 of the suspension absorbs the upward vibration kinetic energy of the wheel 12 once; when the wheel 12, which absorbs kinetic energy through the suspension third mass 18, vibrates upwards, and passes through the anti-resonance vibration reduction structure, the second mounting lower bracket 28 on the second oil cylinder 22 pushes the vehicle body 26 to move upwards through the second spiral spring 27 by the second mounting upper bracket 24, meanwhile, the second oil cylinder 22 compresses hydraulic oil in the lower cavity of the second oil cylinder 22 through the cylinder body, and the hydraulic oil flows to the upper cavity of the second oil cylinder 22 and the second oil storage air chamber 21 through the second adjustable throttle valve 20 and the inertia coil 19, damping and inertia are respectively generated by the second adjustable throttle valve 20 and the inertia coil 19, and the damping and inertia and the rigidity of the second spiral spring 27 perform primary anti-resonance vibration reduction on the upward vibration of the wheel 12, so that the upward vibration input of the vehicle body 26 by the wheel 12 is finally attenuated.

When the automobile runs on a bad road, the automobile body is in a higher state, the rigidity of the traditional vibration reduction structure is provided by a hydro-pneumatic spring formed by the first spiral spring 14 and the first oil storage air chamber 1 filled with oil, the automobile body 26 does not move as soon as the wheel 12 starts to vibrate downwards, the wheel 12 drives the first spiral spring 14 and the first oil cylinder 17 downwards to pull the suspension third mass 18 to move downwards, so that the suspension third mass 18 generates inertia force, and the suspension third mass 18 downwards moves to pull the second spiral spring 27 and the second oil cylinder 22 downwards to drive the automobile body 1 to move downwards; in the moving process, when the downward vibration of the wheel 12 passes through the traditional vibration reduction structure, the first mounting lower bracket 13 on the first piston rod 16 drives the first cylinder body 17 to move downwards through the first spiral spring 14 by the first mounting upper bracket 15, meanwhile, the first piston rod 16 compresses hydraulic oil in the lower oil cavity of the first cylinder body 17 through the piston on the first piston rod and flows to the upper oil cavity of the first cylinder body 17 through the first adjustable throttle valve 29, at the moment, the hydraulic oil in the first oil storage air chamber 1 flows into the oil supplementing the upper oil cavity of the first cylinder body 17, the oil gas spring formed by the oil storage air chamber 1 is connected with the first spiral spring 14 in parallel and performs primary vibration isolation on the downward vibration of the wheel 12, and the first adjustable throttle valve 29 generates damping to perform primary vibration reduction on the downward vibration of the wheel 12; when the wheel 12 vibration-isolated and vibration-reduced by the traditional vibration-reducing structure is transmitted to the second cylinder 22 and the third mass 18 of the suspension, the third mass 18 of the suspension absorbs the kinetic energy of the downward vibration of the wheel 12 once; when the wheel 12 subjected to the absorption of the kinetic energy by the suspension third mass 18 is subjected to the anti-resonance vibration reduction structure, the second installation lower bracket 28 on the second oil cylinder 22 drives the vehicle body 26 to move downwards through the second spiral spring 27 by the second installation upper bracket 24, meanwhile, the cylinder body of the second oil cylinder 22 descends to compress hydraulic oil in an upper oil cavity of the second oil cylinder to flow into a lower oil cavity of the second oil cylinder 22 through the second adjustable throttle valve 20 and the inertia spiral pipe flow 19, at the moment, the hydraulic oil in the second oil storage air chamber 21 flows into the lower oil cavity of the second oil cylinder 22 to supplement oil, damping and inertia capacity are respectively generated by the second adjustable throttle valve 20 and the inertia spiral pipe 19, the damping and inertia capacity and the rigidity of the second spiral spring 27 perform one-time anti-resonance vibration reduction on the upward vibration of the wheel 12, and finally, the downward vibration input of the vehicle body 26 is attenuated by the downward vibration of the wheel 12.

At this time, the automobile runs on a bad road and is in a high-body state, and the stiffness of the traditional vibration reduction structure is provided by the parallel connection of the first spiral spring 14 and the hydro-pneumatic spring formed by the oil-filled first oil storage air chamber 1, so that the stiffness is high, and further the phenomenon that the riding comfort is suddenly deteriorated due to the fact that the suspension is impacted in a limited manner is avoided.

In addition, when the road surface excitation has a large amount of high frequency components, the suspension third mass 18 works together with the antiresonance vibration damping structure to reduce the vehicle body high frequency vibration, and the concrete operation principle is analyzed as follows:

as shown in FIG. 3, which is a schematic diagram illustrating the operation of the self-powered active suspension of the present invention, in FIG. 3, m ₁ Is the mass of the wheel 12; m is m ₂ Is the mass of the body 26; m is m _e Is the inertia capacity of the anti-resonance vibration reduction structure; m is m _c A mass that is the suspension third mass 18; k (k) ₁ Is the equivalent stiffness of the wheel 12; k (k) ₂ Stiffness of the antiresonance vibration damping structure; k (k) _c Stiffness of the traditional vibration damping structure; c ₂ Damping for an antiresonance vibration damping structure; c _c Damping of the traditional vibration reduction structure; q is the vertical input of the uneven road surface; z ₁ For vertical displacement, z, of the wheel 12 ₂ Is the vertical displacement of the vehicle body 26; z _c Is the vertical displacement of the suspension third mass 18. The differential equation for self-powered active suspension motion is:

Wherein:z respectively ₁ First and second derivatives of (a); />Z respectively _c First and second derivatives of (a); />Z respectively ₂ First and second derivatives of (a).

The second derivative of (2) is also the sprung mass acceleration, and the sprung mass acceleration is obtained by solving>The method comprises the following steps:

the transfer function of the vertical displacement of the vehicle body 26 with respect to the road surface input can be found from the equations (1) - (3) as follows:

wherein:

A ₁ ＝(m ₂ +m _e )s ² +c ₂ s+k ₂ ，A ₂ ＝m ₁ s ² +k ₁ ，B ₁ ＝c ₂ s+k ₂ ，B ₂ ＝c _c s+k _c ，s＝j2πf，

wherein: j is an imaginary number; f is the excitation frequency.

From equation (5), the power spectral density of the vertical acceleration of the vehicle body 26 can be derived and calculated according to equation (6):

wherein: u is the speed of the vehicle; g _q (n ₀ ) Is the road surface unevenness coefficient; n is n ₀ Is the road surface space reference frequency; n is n _min Is the pavement space lower cut-off frequency; w is the frequency index.

For example, when each parameter takes a value of: m is m ₁ ＝36kg、m ₂ ＝500kg、m _e ＝12.48kg、m _c ＝18kg、k ₁ ＝300000N/m、k ₂ ＝76842N/m、k _c ＝27404N/m、c ₂ ＝302Ns/m、c _c ＝2369Ns/m、u＝30km/h、G _q (n ₀ )＝4096×10 ^-6 m ² /m ^-1 、n ₀ ＝0.1m ^-1 、n _min ＝0.011m ^-1 When w=2, when m _e And m is equal to _c The comparison of the power spectral density of the vertical acceleration of the vehicle body 26 at the 0 value is shown in fig. 4. FIG. 4 shows that only when m _e And m is equal to _c When none of them is equal to 0, the vertical acceleration power spectrum value of the vehicle body 26 is minimum in the vicinity of the natural frequency of vibration of the wheel 12.

From formula (4), it is apparent that only m _e And m is equal to _c When the spring-loaded mass acceleration is not equal to 0, namely, a traditional vibration reduction structure, namely a suspension third mass and anti-resonance vibration reduction structure is adopted, the spring-loaded mass (vehicle body) acceleration can be related to all system state vectors, and the dimension of an optimized parameter for reducing the spring-loaded mass acceleration is increased from two dimensions to multiple dimensions, so that the spring-loaded mass acceleration is similar to the fact that the spring-loaded mass acceleration is determined by coefficients of a plurality of state variables such as the relative motion speed of the suspension, the dynamic deflection of the suspension, the deformation speed of the tire, the dynamic deformation of the tire and the like under the action of active control force of the active suspension. In addition, when the acceleration value of the suspension third mass 18 and the anti-resonance structure relative motion acceleration value increase, m _e And m is equal to _c Absorbing vibration energy between suspensions to store energy, and when the acceleration value of the third mass 18 of the suspension and the relative motion acceleration value of the antiresonance structure are reduced, m _e And m is equal to _c The energy provided between the suspensions plays a role in negative damping, which is the same as the energy provided between the suspensions by the active suspension actuator under the action of an external power source, and the active suspension provided by the invention does not need to be powered by the external power source.

As shown in FIG. 1, the first adjustable throttle valve 29 in the self-powered active suspension is arranged outside the first oil cylinder 17, so that the damping adjustment of the traditional damping structure can be facilitated, and the self-powered active suspension has good multi-type automobile adaptability. If for single motorcycle type, can remove the first adjustable throttle valve 29 that sets up in the outside of first hydro-cylinder 17, make the upper and lower oil pocket of first hydro-cylinder 17 link through the built-in orifice, can integrate the structure that has the same function with first adjustable throttle valve 29 on the piston of first piston rod 16, can open the orifice that link up from top to bottom on the piston of first piston rod 16 and replace first adjustable throttle valve 29, at this moment, only need connect first oil storage air chamber 1 with hydraulic oil pipe to the lower oil pocket lower part of first hydro-cylinder 17 or the upper oil pocket upper part of first hydro-cylinder 17 one of the oil ports, the oil port that will not connect is blocked at the same time, namely need not to form the connecting oil circuit with the upper oil pocket upper oil port in the lower oil pocket lower part of first hydro-cylinder 17 any more, in order to simplify the structure, vehicle body height and suspension rigidity adjustable device 30 still connect first oil storage air chamber 1 and first hydro-cylinder 17 respectively, this structure is within the scope of the invention. When the vehicle body height and suspension rigidity adjustable device 30 supplies oil in operation, hydraulic oil in the first oil storage air chamber 1 enters the first oil cylinder 17 through an oil port at the lower part of a lower oil cavity or an oil port at the upper part of an upper oil cavity of the first oil cylinder 17 connected with the first oil storage air chamber 1, after the hydraulic oil enters the first oil cylinder 17 from the oil port at the lower part of the lower oil cavity, the hydraulic oil enters the upper oil cavity upwards through an orifice on a piston of the first piston rod 16 to drive the first piston rod 16 to move downwards relative to the cylinder body of the first oil cylinder 17, and the cylinder body of the first oil cylinder 17 moves upwards relative to the ground, so that the vehicle body 26 rises. Conversely, when hydraulic oil enters the first oil cylinder 17 from the oil port at the upper part of the upper oil cavity, the hydraulic oil enters the lower oil cavity downwards through the throttle on the piston of the first piston rod 16, so that the first piston rod 16 is driven to move upwards relative to the cylinder body of the first oil cylinder 17, and the cylinder body of the first oil cylinder 17 moves downwards relative to the ground, and the vehicle body 26 is lowered.

Claims

1. The utility model provides a height and rigidity adjustable self-powered initiative suspension, includes first hydro-cylinder (17) and second hydro-cylinder (22) directly over, and the cylinder body bottom fixed connection of first hydro-cylinder (17) and second hydro-cylinder (22), characterized by:

the upper end piston end of the first piston rod (16) extends into the first oil cylinder (17) to divide the first oil cylinder (17) into an upper sealed oil cavity and a lower sealed oil cavity which are both used for storing oil, the upper part of an upper cavity of the first oil cylinder (17) is sequentially connected with a first adjustable throttle valve (29), a first oil storage air chamber (1) and the lower part of a lower cavity in series through a hydraulic pipeline, and the lower end of the first piston rod (16) extends downwards out of the first oil cylinder (17) and is fixedly connected with a wheel (12); the space at the upper parts of the wheels (12) and the first oil cylinder (17) is provided with a first spiral spring (14) which is arranged up and down, the lower end of the first spiral spring (14) is fixedly connected with the lower end and the upper end of a first piston rod (16) and is rigidly connected with the cylinder body of the first oil cylinder (17); the lower end piston end of the second piston rod (23) extends downwards in the second oil cylinder (22) to divide the second oil cylinder (22) into an upper sealed oil cavity and a lower sealed oil cavity which both store oil, and the upper end extends upwards out of the second oil cylinder (22) and is fixedly connected with a vehicle body (26); the space at the lower parts of the vehicle body (26) and the second oil cylinder (22) is provided with a second spiral spring (27) which is arranged up and down, the upper end of the second spiral spring (27) is fixedly connected with the upper end and the lower end of the second piston rod (23) and is rigidly connected with the cylinder body of the second oil cylinder (22); the hydraulic pipeline from the first oil storage air chamber (1) to the lower part of the lower chamber of the first oil cylinder (17) is connected with a vehicle body height and suspension rigidity adjusting device (30), and the vehicle body height and suspension rigidity adjusting device (30) can supply oil to the first oil storage air chamber (1) and the first oil cylinder (17) and can also enable oil in the first oil storage air chamber (1) and the first oil cylinder (17) to flow back;

The vehicle body height and suspension stiffness adjustable device (30) comprises a first electromagnetic valve (2), an oil regulating cylinder (10), a third electromagnetic valve (7), an air storage tank (3), a one-way valve (4) and an electric air compressor unit (5) which are sequentially connected in series, wherein the first electromagnetic valve (2) is a normally closed valve, an oil cylinder outlet of the oil regulating cylinder (10) is respectively connected with a first oil storage air chamber (1) and a first oil cylinder (17) through the first electromagnetic valve (2), a normally open second electromagnetic valve (9) is connected to an air path between an air cylinder inlet of the oil regulating cylinder (10) and the third electromagnetic valve (7) in a bypass mode, a pressure sensor (6) is connected to an air path between the third electromagnetic valve (7) and the one-way valve (4) in an external mode, the pressure sensor (6) is connected to the controller (8) through a signal line, and the controller (8) is respectively connected with the electric air compressor unit (5), the first electromagnetic valve (2), the second electromagnetic valve (9) and the third electromagnetic valve (7) through a control signal line.

2. The self-powered active suspension of adjustable height and stiffness as claimed in claim 1 wherein: a third mass (18) of a suspension is fixedly connected to the cylinder bodies of the first cylinder (17) and the second cylinder (22), and the third mass (18) of the suspension is fixedly sleeved outside the cylinder bodies of the first cylinder (17) and the second cylinder (22) and is tightly attached to the outer wall of the cylinder body.

3. The self-powered active suspension of adjustable height and stiffness as claimed in claim 1 wherein: the first spiral spring (14) is coaxially sleeved outside the first piston rod (16) and the first oil cylinder (17), and the second spiral spring (27) is coaxially sleeved outside the second piston rod (23) and the second oil cylinder (22).

4. The self-powered active suspension of adjustable height and stiffness as claimed in claim 1 wherein: the piston of the first piston rod (16) is provided with a throttle hole which is penetrated up and down to replace the first adjustable throttle valve (29), the first oil storage chamber (1) is connected to one of an oil port at the lower part of a lower oil cavity of the first oil cylinder (17) or an oil port at the upper part of an upper oil cavity of the first oil cylinder (17) through a hydraulic oil pipe, and the other oil port which is not connected with the first oil storage chamber (1) is blocked.

5. A method of operating a self-powered active suspension of adjustable height and stiffness as claimed in claim 1, comprising the steps of:

step A: when the automobile is stopped and the engine is not started, the height of the automobile body and the rigidity of the suspension are in an initial set lower automobile height state and a lower rigidity state provided by the first spiral spring (14), and the oil pressure in the first oil storage air chamber (1) is the same as the oil pressure in the upper oil cavity and the lower oil cavity of the first oil cylinder (17);

And (B) step (B): after an automobile engine is started, when the automobile is switched from a good road running mode to a bad road running mode, an automobile body height and suspension rigidity adjustable device (30) supplies oil, hydraulic oil flows into a first oil chamber (1), the oil pressure in the first oil chamber (1) rises to cause part of the hydraulic oil to flow into an upper oil cavity of a first oil cylinder (17) through a first adjustable throttle valve (29), a first piston rod (16) moves downwards relative to the cylinder body of the first oil cylinder (17), the hydraulic oil in a lower oil cavity of the first oil cylinder (17) flows into an upper cavity of the first oil cylinder (17) through the first adjustable throttle valve (29), the cylinder body of the first oil cylinder (17) moves upwards relative to the ground to drive a second oil cylinder (22) body, a second spiral spring (27), a second piston rod (23) and the whole automobile body (26) to move upwards relative to the ground, so that the automobile body (26) rises; the first coil spring (14) and the hydro-pneumatic spring formed by the first hydro-pneumatic chamber (1) jointly provide a larger stiffness;

step C: when the automobile is switched from a bad road running mode to a good road running mode, hydraulic oil in the first oil chamber (1) flows back to the automobile body height and suspension rigidity adjustable device (30), the oil pressure of the first oil chamber (1) is reduced, hydraulic oil in an upper oil cavity of the first oil cylinder (17) flows to a lower oil cavity of the first oil cylinder (17) through a first adjustable throttle valve (29), a first piston rod (16) moves upwards relative to a cylinder body of the first oil cylinder (17), the cylinder body of the first oil cylinder (17) moves downwards relative to the ground, the cylinder body of the first oil cylinder (17) drives a cylinder body of the second oil cylinder (22), a second spiral spring (27), the second piston rod (23) and the automobile body (26) to move downwards integrally relative to the ground, the automobile body (26) is reduced, the first spiral spring (14) compresses downwards and returns to an initial state, and only small rigidity is provided.

6. A method of operating a self-powered active suspension of adjustable height and stiffness as claimed in claim 1, comprising the steps of:

step A1: when the automobile is stopped and the engine is not started, the oil cylinder of the height-adjusting oil cylinder (10) is full of hydraulic oil and the cylinder is empty, the first electromagnetic valve (2) and the third electromagnetic valve are closed (7) normally, and the second electromagnetic valve is opened (9) normally;

step B1: when an automobile engine is started, the controller (8) controls the electric air compressor unit (5) to work, compressed air enters the air storage tank (3) through the one-way valve (4) for storage, and when the pressure sensor (6) detects that the pressure of the air storage tank (3) reaches a control preset value, the electric air compressor unit (5) is closed, and the air storage tank (3) is stopped from being inflated;

step C1: when the automobile is switched from a good road running mode to a bad road running mode, the controller (8) firstly controls the second electromagnetic valve (9) to be closed, then controls the first electromagnetic valve (2) and the third electromagnetic valve (7) to be simultaneously opened, gas in the gas storage tank (3) enters a cylinder of the height-adjusting oil cylinder (10) and pushes hydraulic oil in the oil cylinder of the height-adjusting oil cylinder (10) to be supplied with oil through the first electromagnetic valve (2);

Step D1: after oil supply is completed, the controller (8) firstly controls the first electromagnetic valve (2) and the third electromagnetic valve (7) to be closed simultaneously, then controls the second electromagnetic valve (9) to be opened, and the compressed air in the air cylinder of the height-adjusting oil cylinder (10) is discharged, finally controls the electric air compressor unit (5) to be started again, the compressed air enters the air storage tank (3) for storage, and when the pressure sensor (6) displays that the pressure reaches a preset value, the electric air compressor unit (5) is closed;

step E1: when the automobile is switched from a bad road running mode to a good road running mode, the controller (8) firstly controls the first electromagnetic valve (2) to be opened, hydraulic oil flows back to the oil cylinder of the height-adjusting oil cylinder (10), and the controller (8) controls the first electromagnetic valve (2) to be closed.

7. The method of operating a self-powered active suspension of adjustable height and stiffness as recited in claim 6 wherein: before an automobile engine is shut down and the oil cylinder of the height-adjusting oil cylinder (10) is in a state of being emptied of hydraulic oil, when the automobile is in a bad road running mode, the controller (8) firstly controls the hydraulic oil to flow back to the oil cylinder of the height-adjusting oil cylinder (10); when the oil cylinder of the height-adjusting oil cylinder (10) is in a state of being full of oil, the controller (8) firstly controls the first electromagnetic valve (2) to be closed, and then controls the second electromagnetic valve (9) to be opened.

8. The method of operating a self-powered active suspension with adjustable height and stiffness according to claim 5 or 6, characterized by: the upper part of the upper chamber of the second oil cylinder (22) is sequentially connected with a spiral pipe (19), a second adjustable throttle valve (20), a second oil storage air chamber (21) and the lower part of the lower chamber of the second oil cylinder (22) in series through a hydraulic pipeline; when the automobile is in a good road running mode, the first adjustable throttle valve (29) generates damping to damp and damp the vibration of the wheel (12), and the second adjustable throttle valve (20) and the inertial coil (19) generate damping and inertial coil (27) respectively and the second coil spring (27) perform primary anti-resonance damping on the vibration of the wheel (12); when the automobile is in a bad road running mode, the hydro-pneumatic spring formed by the first oil storage air chamber (1) and the first spiral spring (14) are connected in parallel to perform vibration isolation on the vibration of the wheel (12), the first adjustable throttle valve (29) generates damping to perform vibration reduction on the vibration of the wheel (12), and the second adjustable throttle valve (20) and the inertial volume spiral tube (19) respectively generate damping and inertial volume and the second spiral spring (27) to perform primary anti-resonance vibration reduction on the vibration of the wheel (12).

9. A method of operating a self-powered active suspension of adjustable height and stiffness as claimed in claim 4 wherein: when the device (30) with adjustable vehicle body height and suspension rigidity supplies oil, after hydraulic oil enters from an oil port at the lower part of a lower oil cavity of a first oil cylinder (17), the hydraulic oil enters an upper oil cavity upwards through an orifice to drive a first piston rod (16) to move downwards relative to a cylinder body of the first oil cylinder (17), the cylinder body of the first oil cylinder (17) moves upwards relative to the ground, and a vehicle body (26) rises; when hydraulic oil enters from an oil port at the upper part of an upper oil cavity of the first oil cylinder (17), the throttle downwards enters into a lower oil cavity, the first piston rod (16) is driven to move upwards relative to a cylinder body of the first oil cylinder (17), the cylinder body of the first oil cylinder (17) moves downwards relative to the ground, and a vehicle body (26) is lowered.