CN103352956A - Magneto-rheological damper with asymmetrical controllable damping characteristic - Google Patents

Abstract

The invention discloses a magneto-rheological damper with asymmetric controllable damping characteristics, which comprises a magneto-rheological damper body. The first chamber at the lower end of the cylinder and the second chamber near the upper end of the cylinder, the inside of the piston head is provided with a convection hole connected to the first chamber and the second chamber, and the convection hole is provided for the magneto-rheological fluid to flow from the second chamber. The valve assembly for one-way throttling from the second cavity to the first cavity, the magneto-rheological damper with asymmetric controllable damping characteristics of the present invention can make the recovery controllable damping force greater than the compression controllable damping force, and can A large recovery damping force is generated under a small current, which can prolong the recovery time. It is suitable for vibration control systems that require asymmetric controllable damping, such as motorcycle rear suspensions or other vehicle suspension systems. By changing the magneto-rheological damping The current of the excitation coil of the device realizes semi-active vibration control; the invention has a simple structure, realizes an asymmetric controllable damping force, has low use cost, and is favorable for popularization and use.

Description

Magneto-rheological damper with asymmetric controllable damping characteristics

technical field

The invention relates to a vibration control device, in particular to a magneto-rheological damper with asymmetric controllable damping characteristics.

Background technique

There are three types of dampers: passive, semi-active and active. Ordinary passive dampers cannot adjust the damping force according to changes in external loads. The active control system uses sensors to obtain external load changes so that the system can output the correct damping force. The whole system is relatively complicated. Nowadays, magnetorheological technology and its semi-active control, which are more and more valued by people, combine the advantages of passive and active well, and can adjust the output damping force of the damper according to needs.

The magneto-rheological damper is a shock-absorbing device used in semi-active control suspensions that has appeared in the past two decades. Magnetorheological dampers are the most widely used devices in magnetorheological technology. The magnetorheological damper based on magnetorheological technology has the characteristics of simple structure, continuous and adjustable damping force, large adjustable range of damping force, fast response, excellent stability, and can be combined with microcomputer control. Therefore, the magnetorheological damper has been widely concerned by researchers from various countries in the semi-active suspension. At present, magnetorheological dampers have been initially applied in vehicle suspension systems, vibration control of cable-stayed bridge cables, vibration reduction of offshore platform structures, and vibration isolation of high-rise buildings, showing good application prospects. However, due to the cost and the problem of particle settling in magnetorheological fluid itself, magnetorheological dampers have not been widely used in civilian vehicles at present, and most of them are used in some high-end vehicles and military equipment.

Magnetorheological fluid is composed of ferromagnetic particles, surfactant and suspension. The size of ferromagnetic particles is generally in the range of 1-10um, and it is generally processed by magnetic materials such as iron, cobalt, and nickel; the carrier liquid is usually silicone oil, kerosene, and mineral oil, which have good flame retardancy and temperature stability, and There is no pollution to the environment, and contact with general materials will not cause corrosion; the active agent mainly plays a stabilizing role, preventing ferromagnetic particles from sticking together and causing agglomeration and sedimentation. The molecular structure of this active agent is very special. One end has a great affinity for the surface of magnetic particles and can be firmly adsorbed on the surface of magnetic particles. The other end is an elastic group with an appropriate length that is easily dispersed in the carrier liquid. Therefore, the active agent added in the carrier liquid generally adopts silicon oxide additive or other surfactants.

Magneto-rheological fluid is a kind of smart material. When there is a magnetic field in the magnetorheological fluid, the shear resistance of the liquid will change dramatically, which is the so-called magnetorheological effect. It is precisely because of the ease of control of the magnetorheological effect that magnetorheological fluids are widely used in vibration control. Specifically, magnetorheological fluid can change from a free-flowing liquid to a semi-liquid and semi-solid in a magnetic field, and the transition time between these is very fast (microsecond level). In the free-flowing state, the plastic viscosity of MR fluid is only related to the viscosity of the carrier fluid and the volume fraction of ferromagnetic particles. When an external magnetic field is applied, the performance of the magnetorheological fluid will change with the change of the external magnetic field. Before the magnetic saturation is reached, the greater the magnetic field intensity, the greater the shear resistance. The plastic viscosity of magnetorheological fluid can be regarded as a constant with little change. After an external magnetic field is applied, the MR fluid can flow freely only when the shear stress exceeds the yield stress. Based on the above characteristics of the magnetorheological fluid, the damping force of the magnetorheological damper in the prior art is only controlled by the external magnetic field, that is, by changing the current of the excitation coil, and when the magnetorheological damper is applied to the vehicle During the middle period, due to the large difference in the bumpy state of the vehicle driving under different road conditions, the real-time adjustment performance of the vibration control of the damper is high. Even if combined with the controller, it is impossible to predict the bumpy state of the vehicle to adjust the current of the excitation coil. Real-time adjustment is performed, and the magneto-rheological damper in the prior art has no asymmetrical controllable damping characteristics, and the damping force is basically consistent when the damper performs restoration movement and compression movement under the same conditions. In the motorcycle rear suspension damper, the spring matched with the damper is given a large pre-compression during installation, which causes the damper to have great resistance when it performs compression movement. If the damper itself has a large If the compression resistance is low, it will not be conducive to the normal reciprocating movement of the piston head. Therefore, the recovery resistance is required to be much greater than the compression resistance in the motorcycle rear suspension. If the traditional magneto-rheological damper with symmetrical damping characteristics is used in occasions that require asymmetrical controllable damping characteristics, such as motorcycle rear suspension systems, then the controller must be used to reduce the current when the damper performs compression movement or Turning off the current not only requires the introduction of sensors and control circuits, but also increases the complexity of the system and increases the cost. Therefore, there is currently no corresponding magneto-rheological damper capable of realizing asymmetrical controllable damping characteristics for motorcycle rear suspensions.

Therefore, in order to solve the appeal problem, it is necessary to improve the magnetorheological damper with traditional symmetrical damping characteristics, so that the recovery resistance of the magnetorheological damper is much greater than the compression resistance. On the basis of the magnetorheological damper that maintains the traditional symmetrical damping characteristics, Maintain its restoration damping characteristics, that is, adjust the restoration damping force by adjusting the current, but change its compression damping characteristics, so that the compression resistance is greatly reduced, and there is no need to repeatedly adjust the current during the reciprocating motion transformation process. It is suitable for asymmetric controllable damping In the vibration control system with special characteristics, such as the damper on the rear suspension of motorcycles or other vehicle suspension systems, it has a better shock absorption effect.

Contents of the invention

In view of this, the object of the present invention is to provide a magneto-rheological damper with asymmetric controllable damping characteristics. On the basis of the original circular magnetorheological valve, an asymmetric convection hole and a magneto-rheological damper along the convection hole are added. The valve assembly with one-way throttling of rheological fluid can obtain different damping forces by adjusting the current during the recovery movement, but during the compression movement, the current has little effect on the damping force, and the compression resistance is kept at one Very low level, suitable for vibration control systems that require asymmetrical damping, such as the damper on the rear suspension of a motorcycle or other vehicle suspension systems, to achieve a better shock absorption effect.

The magneto-rheological damper with asymmetric controllable damping characteristics of the present invention includes a magneto-rheological damper body; rheological fluid; the piston head is provided with an excitation coil and the piston head is arranged in the cylinder to divide the inner chamber of the cylinder into a first chamber near the lower end of the cylinder and a second chamber near the upper end of the cylinder; the piston The inside of the head is provided with a convection hole communicating with the first cavity and the second cavity; the convection hole is provided with a valve assembly for one-way throttling of the magnetorheological fluid from the second cavity to the first cavity;

Further, the valve assembly is an elastic reset normally closed structure that can be opened under the action of magneto-rheological fluid pressure;

Further, there are at least two convection holes and each convection hole is evenly distributed along the circumference of the piston head;

Further, the valve assembly is arranged in the second cavity, the valve assembly includes an annular reed and a return spring, the annular reed is arranged coaxially with the piston head and is slidably connected to the piston head in the axial direction; the return spring It is placed between the piston rod and the reed to press the reed on the end face of the piston head to close the convection hole;

Further, the return spring is a tower spring;

Further, the piston rod is provided with a sleeve-shaped stop corresponding to the return spring and the annular reed; the sleeve-shaped stop is clamped and positioned between the piston rod and the piston head, and the sleeve-shaped stop is provided with a radially protruding It is used to support the flange of the return spring; the annular reed is axially slidably matched with the outer wall of the sleeve-shaped stopper;

Further, there are two excitation coils and the winding directions of the two excitation coils are opposite;

Further, the magneto-rheological damper body also includes a guide plate that slides with the inner wall of the cylinder and is used for slidingly guiding the piston rod and the piston head; the outer circumference of the guide plate is fixed with a sealing ring that is sealingly matched with the inner wall of the cylinder; A damping passage for the magnetorheological fluid to flow between the first chamber and the second chamber is provided between the piston head and the cylinder; the guide plate is provided for connecting the first chamber with the damping passage and The flow hole connected to the convection hole and the guide plate can be formed separately and fixedly connected with the piston head through threads, or integrally formed with the piston head;

Further, the upper end of the cylinder is provided with an upper sealing assembly that is sealingly connected to the piston rod and the cylinder; the upper sealing assembly includes an upper end cover, an upper end cover rubber seal, a fixed Z-shaped card, a Z-shaped card, a sliding plate, and an oil seal card , an oil seal and a safety pad in the cylinder; the upper end of the piston rod is fixed with an upper joint; the lower end of the upper joint is set on the outer wall of the piston rod to be provided with a safety pad outside the cylinder; the lead wire of the excitation coil is along the axis of the piston head and the piston rod Set and lead out from the upper end joint; the lower end of the cylinder is sealed and connected with a lower end joint; the lower end joint is provided with an air bag communicating with the first cavity; the lower end joint and the cylinder are sealed and connected by piping or thread;

Further, the cylinder and the piston head are made of high magnetic permeability material, and when the guide plate and the piston head are integrally formed, they are also made of high magnetic permeability material; the sleeve stopper, piston rod and upper sealing assembly are made of It is made of magnetically permeable material and is also made of nonmagnetically permeable material when the guide disc is formed separately; the excitation coil is wound by enameled wire.

The beneficial effects of the present invention are: the magnetorheological damper with asymmetric controllable damping characteristics of the present invention, on the basis of the original circular magnetorheological valve, adds asymmetric convection holes and magnetorheological dampers along the convection holes. The valve assembly with one-way throttling of fluid can obtain different damping forces by adjusting the current during the recovery movement, but during the compression movement, the current has little effect on the damping force, and the compression resistance is kept at a very low level. It is suitable for vibration control systems that require asymmetric damping, such as the damper on the rear suspension of a motorcycle or other vehicle suspension systems, and semi-active vibration control is achieved by changing the current of the magneto-rheological damper excitation coil; this The invention has simple structure, realizes asymmetrical controllable damping force, is easy to operate, can save energy consumption, has low use cost, and is favorable for popularization and use.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing and embodiment:

Fig. 1 is the structural representation of compression stroke of the present invention;

Fig. 2 is a structural schematic diagram of the recovery stroke of the present invention;

Fig. 3 is the enlarged view of place A of Fig. 1;

Fig. 4 is the enlarged view of place B of Fig. 2;

Fig. 5 is the schematic diagram of monopole structure of the present invention;

Fig. 6 is a schematic diagram of the fixed connection structure in which the piston rod extends into the piston head;

Fig. 7 is a schematic diagram of a fixed connection structure through which the piston rod penetrates the piston head.

Detailed ways

Fig. 1 is a structural schematic diagram of the compression stroke of the present invention, Fig. 2 is a structural schematic diagram of the recovery stroke of the present invention, Fig. 3 is an enlarged view of A in Fig. 1, Fig. 4 is an enlarged view of B in Fig. 2, and Fig. 5 is a unit of the present invention A schematic diagram of the pole structure, Figure 6 is a schematic diagram of the fixed connection structure of the piston rod extending into the piston head, and Figure 7 is a schematic diagram of the fixed connection structure of the piston rod penetrating the piston head, as shown in the figure: the magnetic flow of the asymmetric controllable damping characteristic of this embodiment The variable damper includes a magneto-rheological damper body; the magneto-rheological damper body includes a cylinder 14, a piston rod 4, a piston head 22 and a magneto-rheological fluid filled in the inner cavity of the cylinder 14; the piston head 22 is provided with an excitation coil 20 and the piston head 22 is located in the cylinder 14 to divide the inner cavity of the cylinder 14 into a first chamber 26 near the lower end of the cylinder 14 and a second chamber 15 near the upper end of the cylinder 14; The upper end of 14 refers to the end of the cylinder 14 corresponding to the extension of the piston rod 4; the inside of the piston head 22 is provided with a convection hole 21 connected to the first cavity 26 and the second cavity 15, effectively utilizing the volume of the piston head 22 The convection hole 21 is provided with a valve assembly for one-way throttling of the magnetorheological fluid from the second cavity 15 to the first cavity 26; the piston head 22 is made of a magnetically conductive material and the piston head 22 is connected to the cylinder A damping channel 19 is provided between the cylinders 14 for the magnetorheological fluid to flow between the first chamber 26 and the second chamber 15. During the compression stroke, as shown in FIG. The flow path and direction of the liquid, because the magnetic field inside the exciting coil 20 is concentrated and distributed inside the piston head 22, the magnetic field in the convection hole 21 is relatively weak, so the magnetorheological fluid can easily flow from the first cavity 26 to the second through the convection hole 21. The cavity 15, and the relationship between the resistance and the current is very small, so that the compression damping force is kept at a very low level; when the stroke is restored, it is shown in Figure 2: where the dotted line and the arrow indicate the flow path and direction of the magnetorheological fluid , the convection hole 21 is partially or completely throttled through the valve assembly, so that most or all of the magnetorheological fluid flows from the second cavity 15 to the first cavity 26 through the damping channel 19, and the magnetic flow through the damping channel 19 The variable liquid produces a large damping force due to the action of the magnetic field, that is, the restoration damping force, whose magnitude is proportional to the magnetic induction intensity in the damping channel 19, and the magnitude of the restoration damping force can be controlled by adjusting the current of the excitation coil 20, and the excitation coil 20 It can be set to one or more, all of which can achieve the purpose of the present invention, and can realize real-time adjustment of the restoration damping force according to the bumpy state of the vehicle, keep the compression resistance at a very low level, and can achieve a better shock absorption effect.

In this embodiment, the valve assembly is an elastic reset normally closed structure that can be opened under the pressure of the magnetorheological fluid; the opening of the valve assembly, that is, the magnetorheological fluid flows from the first cavity 26 through the convection hole 21 to The size of the cross-sectional area of the second cavity 15 changes in direct proportion to the pressure of the magneto-rheological fluid. When it is applied to a vehicle, the compression damping force can be adjusted in real time according to the bumpy state of the vehicle, which can achieve a better shock absorption effect.

In this embodiment, there are at least two convection holes 21 and each convection hole 21 is evenly distributed along the circumference of the piston head 22; the force on the piston head 22 is uniform, and the radial component force damage of the piston head 22 due to uneven force is avoided. The connecting structure of the piston rod 4, the piston head 22 and the cylinder barrel 14 ensures the service life.

In this embodiment, the valve assembly is arranged in the second cavity 15, and the valve assembly includes an annular reed 18 and a return spring 17. The annular reed 18 is arranged coaxially with the piston head 22 and is slidably connected to the piston head 22 in the axial direction. Piston head 22; the return spring 17 bounces between the piston rod 4 and the reed 18 to press the reed 18 on the end face of the piston head 22 to close the convection hole 21; the structure is simple and easy to manufacture. When applied to vehicles, By adopting the return spring 17 with a certain elastic modulus, the opening of the convection hole 21 can be controlled corresponding to the vehicle load and the corresponding bumpy state, which has strong practicability.

In this embodiment, the return spring 17 is a tower spring, i.e. a conical spring, which has a large amount of compression, so a relatively short tower spring can achieve a larger opening range of the convection hole 21, making the valve assembly compact in structure, Good stability.

In this embodiment, the piston rod 4 is provided with a sleeve-shaped stopper 16 corresponding to the return spring 17 and the annular reed 18; the sleeve-shaped stopper 16 is clamped and positioned between the piston rod 4 and the piston head 22. The block 16 is provided with a radially protruding flange for supporting the back-moving spring 17; the annular reed 18 is axially slidably matched with the outer wall of the sleeve block 16; the piston head 22 and the piston rod 4 are fixed by threaded connection; the piston head 22 and the connecting structure of the piston rod 4 can be the structure shown in Figure 1, that is, the upper end of the piston head 22 is axially provided with a connecting screw, and the lower end of the piston rod 4 is provided with a connecting screw hole corresponding to the connecting screw in the axial direction; it can also be the structure shown in Figure 5 , that is, the lower end of the piston rod 4 is axially provided with a connecting screw, and the upper end of the piston head 22 is provided with a connecting screw hole corresponding to the connecting screw in the axial direction; it can also be the structure shown in Figure 6, that is, the axial length of the lower end of the piston rod 4 is greater than that of the piston head 22 of the long connecting screw, the piston head 22 is provided with a connecting through hole corresponding to the long connecting screw in the axial direction, so that the long connecting screw protrudes from the connecting through hole and the piston head 22 is locked and fixed on the piston rod 4 through the connecting nut. Purpose of the present invention: the sleeve-shaped stopper 16 is detachably placed on the corresponding connecting screw or long connecting screw for positioning, so that the annular reed 18 is slidably matched with the sleeve-shaped stopper 16, and can be replaced when the sleeve-shaped slider is worn, which is beneficial to reduce Cost of use, at the same time, the return spring 17 can be reliably supported and positioned through the flange, and there is no need to process a large step surface on the piston rod 4, which is beneficial to reduce the radial dimension of the piston rod 4, save materials, reduce weight and ensure the second cavity 15 capacity for improved vibration control performance.

In this embodiment, there are two excitation coils 20 and the winding directions of the two excitation coils 20 are opposite to generate two opposite magnetic fields. It is isolated from the magneto-rheological fluid, so as to prevent the magneto-rheological fluid from repeatedly rubbing against the exciting coil 20 to damage the coil and cause a short circuit.

In this embodiment, the magneto-rheological damper body also includes a guide plate 24 for slidingly guiding the piston rod 4 and the piston head 22 in sliding fit with the inner wall of the cylinder 14; the outer circumference of the guide plate 24 is fixed with a A sealing ring 25 sealingly fitted on the inner wall of the cylinder 14; a damping channel 19 for the magnetorheological fluid to flow between the first cavity 26 and the second cavity 15 is provided between the piston head 22 and the cylinder 14; The guide plate 24 is provided with a flow hole 23 for connecting the first cavity 26 with the damping channel 19 and the convection hole 21. The guide plate 24 can be formed separately and fixedly connected with the piston head 22 by threads, or can be connected with the piston head 22. Integral molding; the guide disc 24 can be a plate-shaped or sleeve-like structure. When the guide disc 24 is a plate-shaped structure, as shown in Figure 1, the guide disc 24 is coaxially arranged with the piston head 22 and the center of the guide disc 24 is aligned with the piston head. The center of 22 is connected and fixed, so that an annular groove 30 is formed between the guide disc 24 and the piston head 22, the flow holes 23 are axially arranged and evenly distributed around the axis of the guide disc 24, the flow holes 23 pass through the annular groove 30 and the damping passage 19 and The convection hole 21 communicates; when the guide disc 24 is a sleeve-like structure, as shown in Figure 7, the guide disc 24 is coaxially arranged with the piston head 22 and the side wall of the guide disc 24 is fixedly connected to the end face of the piston head 22, and the guide disc inner hole In communication with each convection hole 21, the side wall of the guide plate 24 is radially provided with a bypass hole 29 for connecting the inner hole of the guide plate with the damping passage 19, so the combination of the inner hole of the guide plate and the bypass hole 29 forms a flow hole 23 ; Realize the sliding fit between the piston head 22 and the cylinder barrel 14 while forming the damping channel 19, and the output of the damping force is large, abandoning the structure in the prior art where the lower end of the piston rod 4 protrudes out of the bottom of the cylinder barrel 14 for sliding fit, greatly shortening The overall length is reduced, the sealing fit area is reduced, which is beneficial to reduce leakage and ensure vibration control performance.

In this embodiment, the upper end of the cylinder 14 is provided with an upper sealing assembly that is sealed and connected to the piston rod 4 and the cylinder 14; the upper sealing assembly includes an upper end cover 6, an upper end cover rubber seal 7, a fixed Z-shaped clip 8, The Z-shaped card 9, the sliding plate 10, the oil seal card 11, the oil seal 12 and the safety pad 13 in the cylinder can prevent the oil leakage phenomenon of the damper during operation through the upper sealing assembly; the upper end of the piston rod 4 is fixed with an upper end joint 1; Located at the lower end of the upper end joint 1 and sleeved on the outer wall of the piston rod 4, there is an outer cylinder safety pad 3, which can protect the damper from damage when the damper bears a large external load; the lead wire 2 of the excitation coil 20 runs along the piston head. 22 and the axis of the piston rod 4 are set and drawn out from the upper joint 1, and at least part of the upper joint 1, the piston rod 4 and the piston head 22 are provided with a central hole 5 for accommodating the lead wire; the lower end of the cylinder 14 is sealed and connected with A lower end joint 28; an O-ring 27 for sealing is provided between the lower end joint 28 and the cylinder 14; the lower end joint 28 is provided with an air bag communicated with the first cavity 26, which can effectively compensate the piston rod 4 and the piston head 22 The volume change of the first cavity 26 caused by the reciprocating movement; the lower end joint 28 and the cylinder 14 are sealed and connected by piping or thread, the connection structure is stable, easy to process and manufacture, and is conducive to sealing.

In this embodiment, the cylinder barrel 14 and the piston head 22 are made of high magnetic permeability material, and when the guide plate 24 and the piston head 22 are integrally formed, they are also made of high magnetic permeability material; The piston rod 4 and the upper sealing assembly are made of non-magnetic material and when the guide disc 24 is formed separately, it is also made of non-magnetic material, which can ensure that most of the magnetic force lines in the magnetic field circuit pass through the damping channel 19, and can fully exert the vertical force. The effect of the magnetic field on the magnetorheological fluid can effectively control the magnitude of the damping force, improve control efficiency, and reduce power consumption; the exciting coil 20 is wound by enameled wire and has good performance.

Finally, it is noted that the above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be carried out Modifications or equivalent replacements without departing from the spirit and scope of the technical solution of the present invention shall be covered by the claims of the present invention.

Claims (10)

1. A magnetorheological damper with asymmetric controllable damping characteristics, characterized in that: it comprises a magnetorheological damper body; the magnetorheological damper body comprises a cylinder, a piston rod, a piston head and a cylinder filled in The magnetorheological fluid in the inner cavity of the cylinder; the piston head is provided with an excitation coil and the piston head is arranged in the cylinder to divide the inner cavity of the cylinder into a first cavity near the lower end of the cylinder and a second cavity near the upper end of the cylinder. cavity; the inside of the piston head is provided with a convection hole connected to the first cavity and the second cavity; the convection hole is provided with a one-way joint for the magnetorheological fluid from the second cavity to the first cavity flow valve assembly. 2. The magneto-rheological damper with asymmetric controllable damping characteristics according to claim 1, characterized in that: the valve assembly is an elastic reset normally closed structure that can be opened under the pressure of the magneto-rheological fluid. 3 . The magneto-rheological damper with asymmetrical controllable damping characteristics according to claim 2 , wherein there are at least two convection holes, and the convection holes are evenly distributed along the circumference of the piston head. 4 . 4. The magneto-rheological damper with asymmetric controllable damping characteristics according to claim 3, characterized in that: the valve assembly is arranged in the second cavity, the valve assembly includes an annular reed and a return spring, the The annular reed is arranged coaxially with the piston head and is slidably connected to the piston head in the axial direction; the return spring springs up between the piston rod and the reed to press the reed on the end surface of the piston head to close the convection hole. 5. The magneto-rheological damper with asymmetric controllable damping characteristics according to claim 4, characterized in that: the return spring is a tower spring. 6. The magneto-rheological damper with asymmetric controllable damping characteristics according to claim 5, characterized in that: the piston rod is provided with a sleeve-shaped stop corresponding to the return spring and the annular reed; the sleeve-shaped stop Clamping is positioned between the piston rod and the piston head, and the sleeve-shaped stopper is provided with a radially protruding flange for supporting the return spring; the annular reed is axially slidably matched with the outer wall of the sleeve-shaped stopper. 7 . The magneto-rheological damper with asymmetrical controllable damping characteristics according to claim 6 , wherein there are two excitation coils and the winding directions of the two excitation coils are opposite. 8. The magneto-rheological damper with asymmetric controllable damping characteristics according to claim 7, characterized in that: the magneto-rheological damper body also includes a sliding fit with the inner wall of the cylinder for aligning the piston rod and the piston. The guide plate for sliding guidance of the head; the outer circumference of the guide plate is fixed with a sealing ring that is sealingly matched with the inner wall of the cylinder; the piston head and the cylinder are provided for supplying the magnetorheological fluid in the first cavity and the second cavity The damping channel for the flow between the cavities; the guide plate is provided with a flow hole for communicating the first cavity with the damping channel and the convection hole; the guide plate can be formed separately and fixedly connected with the piston head through threads, and can also be connected with the piston The head is integrally formed. 9. The magneto-rheological damper with asymmetric controllable damping characteristics according to claim 8, characterized in that: the upper end of the cylinder is provided with an upper seal assembly that is sealingly connected to the piston rod and the cylinder; the upper seal The assembly includes the upper end cover, the rubber seal of the upper end cover, the fixed Z-shaped card, the Z-shaped card, the sliding plate, the oil seal card, the oil seal and the safety pad in the cylinder; the upper end of the piston rod is fixed with the upper end joint; The outer wall of the rod is provided with a safety pad outside the cylinder; the lead wire of the excitation coil is arranged along the axis of the piston head and the piston rod and is drawn out from the upper end joint; the lower end of the cylinder is sealed and connected with a lower end joint; the lower end joint is provided with a The air bag communicated with the first cavity; the lower end joint is sealed and connected with the cylinder through rolling edge or thread. 10. The magneto-rheological damper with asymmetric controllable damping characteristics according to claim 9, characterized in that: the cylinder and the piston head are made of high magnetic permeability material and when the guide plate and the piston head are integrally formed It is also made of high magnetic permeability material; the sleeve block, piston rod and upper sealing assembly are made of non-magnetic material and also when the guide plate is formed separately; the excitation coil is made of Enameled wire is wound.

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