CN117905842A - Negative-rigidity magnetic vibration isolator based on metal rubber - Google Patents

Abstract

The invention provides a negative-rigidity magnetic vibration isolator based on metal rubber, which comprises the following components: a hydraulic damper; a spring; the metal rubber negative stiffness electromagnetic device comprises a limiting cylinder, an upper permanent magnet ring, a lower permanent magnet ring, a metal rubber ring and a coil, wherein the metal rubber ring is fixedly sleeved on the piston rod, the movable range of the metal rubber ring in the limiting cylinder is smaller than that of the piston in the cylinder barrel, when the piston is positioned at the initial position in a non-working state in the cylinder barrel, the metal rubber ring is positioned at a magnetic force balance position between the upper permanent magnet ring and the lower permanent magnet ring, and the coil is wound on the outer wall of the limiting cylinder; and the control system is connected with the coil and is used for receiving vibration signals of the vehicle body and the wheels and controlling the coil current according to the received vibration signals. The invention realizes the adjustable and controllable rigidity of the suspension, so that the system has lower initial vibration isolation frequency and vibration isolation frequency band, thereby improving the driving comfort and the steering stability of the automobile and simultaneously increasing the applicability of the automobile.

Description

A negative stiffness magnetic vibration isolator based on metal rubber

Technical Field

The invention relates to the technical field of automobile suspension systems, in particular to a negative stiffness magnetic vibration isolator based on metal rubber.

Background technique

As an important part of the car, the suspension system connects the car body and the wheels. Its function is to buffer and attenuate the impact from the road. The quality of the suspension directly affects the driving safety and ride comfort of the car. The vibration isolator is the most important component in the vehicle suspension system. The suspension system is mainly divided into passive suspension and active suspension. Passive suspension refers to the suspension whose stiffness and damping coefficient will not change with the external state. During the driving process of the car, the stiffness and vibration isolator damping of this suspension cannot be controlled and adjusted. This passive suspension is difficult to take into account the requirements of driving comfort and handling stability of the car. It makes it difficult for the car to drive when passing through certain rugged sections. Severe bumps will not only make the occupants uncomfortable, but even cause the suspension to break down, causing accidental dangers. However, due to the simple structure and low cost of passive suspension, most cars are generally equipped with passive suspension. Active suspension refers to the suspension whose stiffness and vibration isolator damping can be adjusted in real time according to the operating conditions. The electronically controlled active suspension uses the ECU to control the corresponding actuators, automatically adjusting the stiffness of the suspension and the damping of the vibration isolator to adapt to the changes in various complex road conditions and the different requirements of the suspension system for driving needs, thereby improving the driving comfort and handling stability of the car. However, the active suspension system is complex and expensive, and is generally used in high-end and luxury cars. There is also the problem that the circuit failure cannot provide stable vibration isolation performance.

Summary of the invention

The purpose of the present invention is to solve the problems existing in the above-mentioned prior art and to provide a negative stiffness magnetic vibration isolator based on metal rubber.

In order to achieve the above object, the present invention is implemented through the following technical solutions:

A negative stiffness magnetic vibration isolator based on metal rubber, comprising:

A hydraulic damper, wherein an upper hanging piece and an upper pressure cover are arranged on the piston rod of the hydraulic damper, and a lower hanging piece and a lower pressure cover are arranged on the cylinder barrel of the hydraulic damper;

A spring, which is sleeved on the hydraulic damper, and has an upper end abutting against the upper gland and a lower end abutting against the lower gland;

A metal rubber negative stiffness electromagnetic device, comprising a limiting cylinder, an upper permanent magnetic ring, a lower permanent magnetic ring, a metal rubber ring and a coil, wherein the limiting cylinder is fixed to the upper end of the cylinder, the upper permanent magnetic ring and the lower permanent magnetic ring are respectively fixed to the upper and lower ends of the limiting cylinder, the piston rod movably passes through the upper permanent magnetic ring, the lower permanent magnetic ring and the limiting cylinder, the metal rubber ring is fixedly sleeved on the piston rod, the movable range of the metal rubber ring in the limiting cylinder is smaller than the movable range of the piston in the cylinder, when the piston is located at an initial position in a non-working state in the cylinder, the metal rubber ring is located at a magnetic equilibrium position between the upper permanent magnetic ring and the lower permanent magnetic ring, the coil is wound around the outer wall of the limiting cylinder, the upper limit of the coil winding range is the midpoint of the distance between the upper surface of the metal rubber ring at the magnetic equilibrium position and the lower surface of the upper permanent magnetic ring, and the lower limit of the coil winding range is the midpoint of the distance between the lower surface of the metal rubber ring at the equilibrium position and the upper surface of the lower permanent magnetic ring;

The control system is connected to the coil and is used to receive vibration signals of the vehicle body and the wheel and control the coil current according to the received vibration signals.

Preferably, the control system includes a displacement sensor, a central control unit and a signal amplifier which are sequentially signal-connected, the signal amplifier is connected to the coil, the displacement sensor is used to collect vibration signals of the vehicle body and the wheels respectively, and transmit the vibration signals to the central control unit, the central control unit is used to process the received vibration signals and transmit the processed signals to the signal amplifier, and the signal amplifier generates the required signal to control the coil current.

Preferably, the upper hanging member and the lower hanging member are both hanging rings.

Preferably, the piston rod and the limiting cylinder are both made of low magnetic permeability materials.

Preferably, the metal rubber ring is made of 304 stainless steel wire.

Preferably, the upper permanent magnet ring and the lower permanent magnet ring are both neodymium iron boron rare earth permanent magnets.

Compared with the prior art, the beneficial effects of the present invention are:

The present invention adds a metal rubber negative stiffness electromagnetic device to the traditional passive suspension shock absorber without changing the structure of the traditional passive suspension hydraulic damper, so the damping of the suspension system is not changed, and the suspension stiffness is adjustable and controllable, so that the system has a lower starting vibration isolation frequency and vibration isolation frequency band, thereby improving the driving comfort and handling stability of the car, and increasing the applicability of the vehicle. In addition, when the circuit fails, the permanent magnet can still attract the metal rubber to generate negative stiffness. At the same time, since the metal rubber ring itself is a porous structure with excellent vibration isolation performance, it has excellent vibration isolation performance and can prevent the suspension from breaking through. In addition, the present invention also has the advantages of simple and compact mechanical structure and no noise.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the external structure of a negative stiffness magnetic vibration isolator based on metal rubber according to the present invention;

FIG2 is a schematic diagram of the internal structure of the negative stiffness magnetic vibration isolator based on metal rubber of the present invention;

FIG3 is a schematic diagram of the working principle of the metal rubber negative stiffness electromagnetic device of the present invention;

FIG4 is a diagram of a “quarter” metal rubber negative stiffness magnetic suspension model.

Description of Reference Numerals

10-hydraulic damper, 11-piston rod, 12-upper hanging piece, 13-upper pressure cover, 14-cylinder barrel, 15-lower hanging piece, 16-lower pressure cover, 17-piston;

20-spring;

30-metal rubber negative stiffness electromagnetic device, 31-limiting cylinder, 32-upper permanent magnetic ring, 33-lower permanent magnetic ring, 34-metal rubber ring, 35-coil.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the application equally.

As shown in Figures 1 to 4, this embodiment provides a negative stiffness magnetic vibration isolator based on metal rubber, including: a hydraulic damper 10, wherein an upper hanging piece 12 and an upper pressure cover 13 are provided on a piston rod 11 of the hydraulic damper 10, and a lower hanging piece 15 and a lower pressure cover 16 are provided on a cylinder 14 of the hydraulic damper 10; a spring 20, which is sleeved on the hydraulic damper 10, and the upper end abuts against the upper pressure cover 13, and the lower end abuts against the lower pressure cover 16; a metal rubber negative stiffness electromagnetic device 30, including a limit cylinder 31, an upper permanent magnetic ring 32, a lower permanent magnetic ring 33, a metal rubber ring 34 and a coil 35, wherein the limit cylinder 31 is fixed at the upper end of the cylinder 14, and the upper permanent magnetic ring 32 and the lower permanent magnetic ring 33 are respectively fixed at the upper and lower ends of the limit cylinder 31, and the piston rod 11 movably passes through the upper permanent magnetic ring 32, the lower permanent magnetic ring 33 and the limit cylinder 31, and the metal The rubber ring 34 is fixedly sleeved on the piston rod 11, and the movable range of the metal rubber ring 34 in the limiting cylinder 31 is smaller than the movable range of the piston 17 in the cylinder 14. When the piston 17 is located at the initial position in the non-working state in the cylinder 14, the metal rubber ring 34 is located at the magnetic balance position between the upper permanent magnet ring 32 and the lower permanent magnet ring 33. The coil 35 is wound around the outer wall of the limiting cylinder 31, and the upper limit of the winding range of the coil 35 is the midpoint of the distance between the upper surface of the metal rubber ring 34 located at the magnetic balance position and the lower surface of the upper permanent magnet ring 32, and the lower limit of the winding range of the coil 35 is the midpoint of the distance between the lower surface of the metal rubber ring 34 located at the balance position and the upper surface of the lower permanent magnet ring 33. A control system is connected to the coil 35, and is used to receive vibration signals of the vehicle body and the wheel, and control the current of the coil 35 according to the received vibration signals.

In some embodiments, as shown in FIG. 2 , the control system includes a displacement sensor, a central control unit, and a signal amplifier that are sequentially signal-connected, the signal amplifier being connected to the coil, the displacement sensor being used to collect vibration signals of the vehicle body and the wheels, respectively, and transmitting the vibration signals to the central control unit, the central control unit being used to process the received vibration signals, and transmitting the processed signals to the signal amplifier, and the signal amplifier generating the required signal to control the coil current.

Specifically, metal rubber is a porous elastic material prepared by a specific process method, using metal wire as the raw material. In terms of the preparation process, it has the advantages of low equipment and tooling consumption and low preparation cost, and its porosity is controllable and easy to be made into various complex shapes, resulting in the metal rubber not only having the metallic properties of rubber but also the rubber properties of metal. In this embodiment, on the basis of the passive suspension isolator, a metal rubber negative stiffness electromagnetic device 30 is arranged on the passive suspension isolator, and the negative stiffness provided by the metal rubber negative stiffness electromagnetic device 30 and the positive stiffness provided by the spring 20 are connected in parallel, thereby reducing the total stiffness of the suspension system. For the sake of convenience of explanation, this embodiment simplifies the vertical dynamics model of the whole vehicle into a two-degree-of-freedom suspension model to illustrate the working principle of the negative stiffness magnetic isolator based on metal rubber in this embodiment.

The working principle of the negative stiffness magnetic vibration isolator based on metal rubber in this embodiment is as follows: first, the control system uses a displacement sensor to measure the vibration signals of the vehicle body and the wheel caused by the excitation of the road surface unevenness, and transmits the measured signal to the central control unit. After signal processing, the relative displacement of the vehicle body and the wheel is obtained. Then, the processed signal is transmitted to the signal amplifier. After processing by the signal amplifier, the optimal current that satisfies the stability of the system is generated. The direct current flows through the coil 35 and forms the electromagnet poles with the metal rubber ring 34 as shown in FIG3. During the vibration process, when the metal rubber ring 34 is axially offset near the magnetic equilibrium position, the metal rubber ring 34 will be attracted in the same direction as the offset, so that the metal rubber ring 34 continues to move in the offset direction and exhibits negative stiffness near the magnetic equilibrium position. And it is connected in parallel with the positive stiffness provided by the spring 20 in the traditional shock absorber, thereby reducing the total stiffness of the suspension system. The suspension equipped with the negative stiffness magnetic vibration isolator based on metal rubber in this embodiment has a higher load-bearing capacity and lower motion stiffness in the working position, which effectively isolates the vibration of the car during driving. In addition, if the circuit does not work properly, the upper permanent magnet ring 32 and the lower permanent magnet ring 33 still have an attraction to the metal rubber ring 34, thereby generating negative stiffness, which plays a role in improving the vibration isolation frequency band. And on a rough road surface, when the vehicle body vibrates violently, since the metal rubber ring 34 itself is a porous structure with excellent vibration isolation performance, the movable range of the metal rubber ring 34 in the limit cylinder 31 is smaller than the movable range of the piston 17 in the cylinder 14. This ensures that under extreme conditions, when the piston 17 is about to hit the limit block, the metal rubber ring 34 moving in the limit cylinder 31 will first collide with the upper and lower permanent magnet rings. Due to the excellent vibration isolation performance of the metal rubber ring 34 itself, it can prevent the suspension from breaking through. Figure 4 is a "quarter" metal rubber negative stiffness magnetic suspension model diagram. In the figure: _ms and _mu are the non-suspension mass and the suspension mass respectively; ks _is the positive stiffness of the suspension provided by the spring 20, _kv is the variable stiffness generated by adjusting the attraction force by changing the current when the coil 35 works normally; _kt is the negative stiffness provided by the attraction between the upper and lower permanent magnet rings and the metal rubber ring 34 when the circuit fails or the coil 35 does not work, and the corresponding _kv = 0 at this time; _cs is the fixed damping coefficient of the passive suspension; _ku is the tire stiffness; _Zu and _Zs are the vertical displacement coordinates of the wheel axle and the vehicle body respectively, and the coordinate origins are at their respective equilibrium positions; q is the road surface roughness function.

The dynamic differential equation of the metal rubber negative stiffness magnetic suspension is:

Where k _t <0, k _v <0.

In some embodiments, the upper hanging member 12 and the lower hanging member 15 are both hanging rings.

In some embodiments, in order to prevent the piston rod 11 and the stopper cylinder 31 from interfering with the magnetic effect of the coil 35 on the metal rubber ring 34, the piston rod 11 and the stopper cylinder 31 are made of low magnetic permeability materials, such as aluminum alloy, copper alloy, etc. The material of the metal rubber ring 34 is 304 stainless steel wire, and the upper permanent magnet ring 32 and the lower permanent magnet ring 33 are both neodymium iron boron rare earth permanent magnets with relatively wide application value and high magnetic energy product.

Claims (6)

1. A negative stiffness magnetic vibration isolator based on metal rubber, characterized by comprising: A hydraulic damper, wherein an upper hanging piece and an upper pressure cover are arranged on the piston rod of the hydraulic damper, and a lower hanging piece and a lower pressure cover are arranged on the cylinder barrel of the hydraulic damper; A spring, which is sleeved on the hydraulic damper, and has an upper end abutting against the upper gland and a lower end abutting against the lower gland; A metal rubber negative stiffness electromagnetic device, comprising a limiting cylinder, an upper permanent magnetic ring, a lower permanent magnetic ring, a metal rubber ring and a coil, wherein the limiting cylinder is fixed to the upper end of the cylinder, the upper permanent magnetic ring and the lower permanent magnetic ring are respectively fixed to the upper and lower ends of the limiting cylinder, the piston rod movably passes through the upper permanent magnetic ring, the lower permanent magnetic ring and the limiting cylinder, the metal rubber ring is fixedly sleeved on the piston rod, the movable range of the metal rubber ring in the limiting cylinder is smaller than the movable range of the piston in the cylinder, when the piston is located at an initial position in a non-working state in the cylinder, the metal rubber ring is located at a magnetic equilibrium position between the upper permanent magnetic ring and the lower permanent magnetic ring, the coil is wound around the outer wall of the limiting cylinder, the upper limit of the coil winding range is the midpoint of the distance between the upper surface of the metal rubber ring at the magnetic equilibrium position and the lower surface of the upper permanent magnetic ring, and the lower limit of the coil winding range is the midpoint of the distance between the lower surface of the metal rubber ring at the equilibrium position and the upper surface of the lower permanent magnetic ring; The control system is connected to the coil and is used to receive vibration signals of the vehicle body and the wheel and control the coil current according to the received vibration signals. 2. According to claim 1, a negative stiffness magnetic vibration isolator based on metal rubber is characterized in that: the control system includes a displacement sensor, a central control unit and a signal amplifier which are sequentially signal-connected, the signal amplifier is connected to the coil, the displacement sensor is used to collect vibration signals of the vehicle body and the wheel respectively, and transmit the vibration signals to the central control unit, the central control unit is used to process the received vibration signals and transmit the processed signals to the signal amplifier, and the signal amplifier generates the required signal to control the coil current. 3. The negative stiffness magnetic vibration isolator based on metal rubber according to claim 1, characterized in that the upper hanging piece and the lower hanging piece are both hanging rings. 4. The negative stiffness magnetic vibration isolator based on metal rubber according to claim 1 is characterized in that: the materials of the piston rod and the limiting cylinder are both low magnetic permeability materials. 5. The negative stiffness magnetic vibration isolator based on metal rubber according to claim 1, characterized in that the material of the metal rubber ring is 304 stainless steel wire. 6. A negative stiffness magnetic vibration isolator based on metal rubber according to claim 1, characterized in that: the upper permanent magnetic ring and the lower permanent magnetic ring are both neodymium iron boron rare earth permanent magnets.