Magnetorheological fluid load type damper

Abstract

The invention discloses a magnetorheological fluid load type damper which comprises a composite working medium arranged in a damper working area, and the composite working medium comprises a three-dimensional space net-shaped fiber base body and magnetorheological fluid loaded on the three-dimensional space net-shaped fiber base body. The magnetorheological fluid is in a semi-solid state on the three-dimensional space net-shaped fiber matrix; magnetorheological fluid is loaded on a three-dimensional space net-shaped fiber base body and then arranged in the damper, magnetic particles in the magnetorheological fluid are attached to the net-shaped fiber material base body structure to serve as a working medium of the damper as a whole, the sedimentation problem caused by different densities can be effectively avoided, the damping performance is improved, and the service life of the damper is prolonged. The mechanical property can be improved through the constraint of the three-dimensional space net-shaped fiber base body on the magnetorheological fluid, the using amount of the magnetorheological fluid is relatively small, the cost is lower, then the requirement for sealing of the device is lowered, a sealing device does not need to be specially designed, the structure of the damper is simpler, and the design difficulty of the damper is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to a damper, in particular to a magneto-rheological liquid load type damper. BACKGROUND

[0002] Intelligent materials are materials that can perceive external excitation (such as electricity, magnetism, heat, etc.) and respond quickly to it. As a typical intelligent controllable material, magneto-rheological fluid will change from liquid to semi-solid under external magnetic field excitation, and the stiffness, damping and other characteristics of the material will change greatly, so magneto-rheological materials are widely used in automobile suspensions, building vibration isolation, impact energy absorption and other fields. According to the structure of the damping device, it can be divided into piston type, roller type, disc type and extrusion type. In the traditional magneto-rheological damper, magneto-rheological fluid is used as the working medium to fill the working area, and the physical properties of the magneto-rheological fluid in the working area are changed by the magnetic field generated by the damper coil perpendicular to the working area, thereby generating damping. However, when using magneto-rheological fluid, ferromagnetic particles will settle due to long-term inactivity, resulting in a decline in the performance of the magneto-rheological fluid and even failure. At the same time, since the carrier liquid component of the magneto-rheological fluid is a liquid such as silicone oil, the damper needs to be sealed during use, which will increase the overall weight of the damper and make the structure more complex, making it impossible to miniaturize.

[0003] Therefore, it is necessary to solve the problem of the settling of magneto-rheological fluid in magneto-rheological materials during use, and the problem of complex structure design and high sealing requirements of the damper caused by magneto-rheological fluid. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a magneto-rheological liquid load type damper to solve the problem of the settling of magneto-rheological fluid in magneto-rheological materials during use, and the problem of complex structure design and high sealing requirements of the damper caused by magneto-rheological fluid. While improving the magneto-rheological effect of the damper, the stability and economy are also improved.

[0005] The magneto-rheological liquid load type damper of the present application comprises a composite working medium arranged in the working area of the damper, the composite working medium comprising a three-dimensional space net-like fiber matrix and a magneto-rheological liquid loaded on the three-dimensional space net-like fiber matrix, and the magneto-rheological liquid being in a semi-solid state on the three-dimensional space net-like fiber matrix.

[0006] Further, the magneto-rheological liquid is loaded on the three-dimensional space net-like fiber matrix by impregnation;

[0007] Further, after the magneto-rheological liquid fully impregnates the three-dimensional space net-like fiber, vacuum drying is performed until the three-dimensional space net-like fiber completely locks the magneto-rheological liquid;

[0008] Further, a cycle mode of multiple impregnations and drying is performed;

[0009] Further, the drying temperature is 45-65℃;

[0010] Further, the magneto-rheological fluid comprises base fluid and magnetic particles, the magnetic particles are dispersed and attached in the porous network structure of the three-dimensional space network fiber material, the base fluid is bound to the three-dimensional space network fiber material and can enable the magnetic particles to move in the surface and internal limited space of the three-dimensional space network fiber material;

[0011] Further, the three-dimensional space network fiber is at least one of Kevlar, asbestos, polyethylene fiber, polypropylene fiber, cotton fabric, polyester, silk, synthetic fiber;

[0012] Further, the three-dimensional space network fiber substrate is arranged in the damper working area by cladding and a gap is reserved between the corresponding working surface;

[0013] Further, the gap between the three-dimensional space network fiber substrate and the working surface is 0.1-0.5mm.

[0014] The beneficial effects of the present application are: the magneto-rheological fluid load type damper of the present application loads the magneto-rheological fluid on the three-dimensional space network fiber substrate and then sets it in the damper, the magnetic particles in the magneto-rheological fluid are attached in the network fiber material substrate structure as a whole as the working medium of the damper, which can effectively avoid the sedimentation problem caused by different densities and improve the damping property, the constraint of the three-dimensional space network fiber substrate on the magneto-rheological fluid can improve the mechanical property, and the magneto-rheological fluid does not need to fill the entire damper cylinder as the traditional damper, only the magneto-rheological fluid attached to the three-dimensional space network fiber substrate is needed, the amount of the magneto-rheological fluid is relatively less, the cost is lower, and then the requirement for sealing of the device is reduced, and there is no need to specially design a sealing device, so that the structure of the damper is simpler and the design difficulty of the damper is reduced. By connecting the magneto-rheological fluid and the damper parts through the three-dimensional space network fiber material, the integration of the intelligent material and the device is realized, the integration degree is improved, the universality of the damper is improved, and the damper can be applied to different working modes such as disc type, drum type, piston type and extrusion type. BRIEF DESCRIPTION OF DRAWINGS

[0015] The present application will be further described below in combination with the drawings and examples:

[0016] Figure 1 It is a piston type damper of example 1;

[0017] Figure 2 It is a disc type damper of example 2;

[0018] Figure 3 It is an extrusion type damper of example 3;

[0019] Figure 4 Fig. 4 is a schematic diagram of the working range when no magnetic field is applied;

[0020] Figure 5 Fig. 5 is a schematic diagram of the working range when a magnetic field is applied. DETAILED DESCRIPTION

[0021] Figure 1 Fig. 6 is a piston damper of Example 1; Figure 2 Fig. 7 is a disc damper of Example 2; Figure 3 Fig. 8 is an extrusion damper of Example 3; Figure 4 Fig. 9 is a schematic diagram of the working range when no magnetic field is applied; Figure 5 Fig. 10 is a schematic diagram of the working range when a magnetic field is applied. The magnetorheological fluid load damper of the present application comprises a composite working medium arranged in the working area of the damper, the composite working medium comprising a three-dimensional space net fiber matrix and a magnetorheological fluid loaded on the three-dimensional space net fiber matrix, the magnetorheological fluid being in a semi-solid state on the three-dimensional space net fiber matrix; the three-dimensional space net fiber matrix has a three-dimensional space net porous structure, a large specific surface area, and strong adsorption force, and especially has good oil absorption. The present application mainly realizes the full infiltration of the three-dimensional space net fiber by the magnetorheological fluid after coating one or more layers of three-dimensional space net fiber on the surface of the damper device. The number of coating layers is selected according to the thickness of the three-dimensional space net fiber material and the thickness of the working area of the damper device. The design can use any magnetorheological fluid as long as the magnetorheological fluid can be loaded on the matrix, and the composite medium formed under the action of a magnetic field can move within a limited range or change its physical properties, which can achieve the purpose of the present application. The state of such composite medium is similar to a semi-solid state, which is a state between solid and liquid. The substance in this state has both the fluidity of a liquid and a series of characteristics of a solid, such as maintaining a certain shape and elasticity. Its uniqueness comes from the special properties of the molecular structure. The interaction between molecules is relatively low, so that the substance can deform to a certain extent when subjected to external force, and at the same time it can restore to its original state without external force.

[0022] Of course, the matrix of the present application is not limited to three-dimensional space reticular fibers, and can also be other materials having a porous structure. The magneto-rheological fluid of the present application can comprise the following components: base fluid 1 part, modified magnetic particles 0.15-0.35 parts, thickening agent 0.002-0.02 parts, surfactant 0.005-0.025 parts; the above ratio is based on the mass fraction of the base fluid. The base fluid is dimethyl silicone oil or mineral oil, the thickening agent is fumed silica, and the surfactant is one or a mixture of two or more of oleic acid, stearic acid, and glycerol. The ferromagnetic particles 4 of the magneto-rheological fluid are dispersed and attached in the internal porous network structure of the three-dimensional space reticular fibers 3, and the base fluid is also constrained in the material due to the lipophilicity or hydrophilicity of the three-dimensional space reticular fiber material. At the same time, the whole has a certain fluidity. The base fluid as the main carrier and lubricant of the magnetic particles 4 can make the magnetic particles 4 have limited movement on the surface and inside of the three-dimensional space reticular fiber material 3. When a magnetic field is applied, the magnetic field passes through the upper and lower working surfaces (1, 2) and the reticular fiber material 3 (as shown in Figure 5 The porous space inside the reticular fiber material 3 can make the magneto-rheological fluid move within a limited range and form a chain structure according to the direction of the magnetic induction line, and at the same time, due to the attraction of the magnetic force, the magneto-rheological fluid will form a boundary layer between the reticular fiber material and the upper working surface (1) under the constraint of the reticular fiber material, and at this time, the magneto-rheological fluid will fill this part due to the small gap. When the device is working, it can output force through the breakage and recombination of particle chains as normal magneto-rheological fluid.

[0023] In this embodiment, the magneto-rheological fluid is loaded on the three-dimensional space reticular fiber base by impregnation; after the magneto-rheological fluid is fully impregnated into the three-dimensional space reticular fiber, vacuum drying is performed until the three-dimensional space reticular fiber completely locks the magneto-rheological fluid; on the surface of one side or both sides in the working area, the reticular fiber material is covered on the surface by adhesive means, and the reticular fiber material is at least one of Kevlar, asbestos, polyethylene fiber, polypropylene fiber, cotton fabric, polyester, silk, and synthetic fiber, such as polypropylene spun-bond non-woven fabric. The device covered with three-dimensional space reticular fiber is washed with anhydrous ethanol, and high-temperature drying is performed to clean the impurities on the surface of the material and the device. The device is immersed in the prepared magneto-rheological fluid, the magneto-rheological fluid is fully attached by an ultrasonic dispersion device, and then drying is performed in a drying box. The cycle mode of multiple impregnations and drying is adopted; the purpose of drying is to remove the magneto-rheological fluid that is not absorbed by the polypropylene spun-bond non-woven fabric, in order to prevent the performance of the damper from being reduced due to insufficient absorption after single impregnation, and to prevent the loss of the base fluid of the magneto-rheological fluid on the surface of the polypropylene spun-bond non-woven fabric after drying from being too much to reduce the mobility of the magnetic particles. The impregnation and drying process needs to be repeated for 3-5 times, so that the three-dimensional space reticular fiber on the damper is fully impregnated.

[0024] In this embodiment, the drying temperature is 45-65℃; at this temperature, the unabsorbed magnetorheological fluid can be removed, and the magnetorheological fluid in the three-dimensional space netted fiber can be firmly locked, so that the formed composite medium as a whole has a certain fluidity, and the magnetic particles can have limited movement on the surface and inside of the three-dimensional space netted fiber, and have physical changes under the action of the magnetic field.

[0025] In this embodiment, the magnetorheological fluid includes a base fluid and magnetic particles, the magnetic particles are dispersed and attached in the porous netted structure of the three-dimensional space netted fiber material, and the base fluid is bound to the three-dimensional space netted fiber material and can enable the magnetic particles to have limited movement on the surface and inside of the three-dimensional space netted fiber material.

[0026] In this embodiment, the three-dimensional space netted fiber is at least one of Kevlar, asbestos, polyethylene fiber, polypropylene fiber, cotton fabric, polyester, silk, and synthetic fiber; for example, polypropylene spun-bonded nonwoven fabric, Kevlar fiber cloth, and the like.

[0027] In this embodiment, the three-dimensional space netted fiber substrate is arranged in the damper working area by a cladding manner and a gap is reserved between the three-dimensional space netted fiber substrate and the corresponding working surface, as shown in Figure 4 The cladding means is at least one of adhesion or other physical means, and the gap between the three-dimensional space netted fiber substrate and the working surface is 0.1-0.5mm. The working surface generally refers to the boundary surface of the working area. Due to the attraction of the magnetic force, the magnetorheological fluid will form a boundary layer between the netted fiber material and the upper working surface (1) under the constraint of the netted fiber material. Since the gap is small, at this time the magnetorheological fluid will fill this part. When the device is working, it can realize the output force through the breakage and recombination of the particle chain as the normal magnetorheological fluid. That is, generally the three-dimensional space netted fiber is attached to one side or both sides of the working area, and a gap of about 0.1-0.5mm is left, and does not contact the upper working surface (1).

[0028] Embodiment one

[0029] The raw materials of the magnetorheological fluid include, by weight: 1 part of base fluid, 0.2 parts of modified magnetic particles, 0.01 parts of thickening agent, and 0.015 parts of surfactant; the above ratio is based on the mass fraction of the base fluid. The base fluid is dimethyl silicone oil or mineral oil, the thickening agent is fumed silica, and the surfactant is oleic acid.

[0030] In this example, it is a piston type damper, and the working area is as shown in Figure 1 The gap between the piston and the cylinder constitutes. The netted fiber material used is polypropylene spun-bonded nonwoven fabric. The fixing means is adhesion, and cyanoacrylate is used as the main adhesive.

[0031] As shown in Figure 1As shown in [1], a polypropylene spunbond nonwoven fabric is coated on the piston surface and then bonded to the piston surface with an adhesive. The polypropylene spunbond nonwoven fabric is modified by immersing the piston head in a stearic acid solution, ultrasonically dispersing it, and then vacuum drying it. Impurities are then removed by repeated washing with anhydrous ethanol and repeated drying.

[0032] To prepare a magnetorheological fluid, the magnetic particles are first modified, immersed in an isopropyl alcohol solution for cleaning, stirred for 15 minutes, and then ultrasonically dispersed for 30 minutes. Finally, the isopropyl alcohol solution is dried in a vacuum drying oven below 60°C to obtain dried modified magnetic particles. Then, 1% by mass of a silane coupling agent and hexadecyltrimethylsilane are added to the base liquid, stirred evenly, and the treated magnetic particles are added, ultrasonically dispersed and mixed, and the dispersed solution is placed in a ball mill for 10 hours to obtain a magnetorheological fluid.

[0033] The cleaned and coated piston head is immersed in the magnetorheological fluid. After immersion for 5 minutes, it is removed and placed in a vacuum drying oven at 60°C for 30 minutes to remove the magnetorheological fluid that has not been absorbed by the polypropylene spunbond nonwoven fabric. In order to prevent the performance of the damper from being degraded due to insufficient absorption after a single infiltration, and to prevent the loss of too much magnetorheological fluid base liquid on the surface of the polypropylene spunbond nonwoven fabric after drying, resulting in reduced mobility of the magnetic particles, the infiltration and drying process needs to be repeated 3-5 times to fully infiltrate the polypropylene spunbond nonwoven fabric on the piston head.

[0034] Example 2

[0035] The magnetorheological fluid formulation is as in Example 1.

[0036] This example uses a disc damper with a working range such as Figure 2 The figure shows the gap between the front and back surfaces of the brake disc and the cylinder. The mesh fiber material used is polypropylene spunbond nonwoven fabric. The fixing method is bonding, using cyanoacrylate as the main adhesive.

[0037] like Figure 2 As shown in the figure, a polypropylene spunbond nonwoven fabric is cut to the surface pattern of the brake disc and then coated onto the surface. An adhesive is then used to secure the surface. The brake disc is then immersed in a stearic acid solution to modify the polypropylene spunbond nonwoven fabric. Ultrasonic dispersion is then performed and vacuum drying is performed. Impurities are then removed by repeated washing with anhydrous ethanol and repeated drying.

[0038] The magnetorheological fluid is prepared by first modifying the magnetic particles, immersing them in an isopropyl alcohol solution for cleaning, stirring for 15 minutes, ultrasonic dispersion for 30 minutes, and finally drying in a vacuum drying oven below 60°C. Then 1% mass ratio of silane coupling agent, hexadecyl trimethyl silane is added to the base fluid, stirred uniformly and the treated magnetic particles are added, ultrasonic dispersion mixing is performed, and then the dispersed solution is placed in a ball mill for 10 hours to obtain the magnetorheological fluid.

[0039] The coated and cleaned brake disc is immersed in the magnetorheological fluid, immersed for 5 minutes, removed and placed in a vacuum drying oven at 60°C for vacuum drying for 30 minutes. This process is repeated 3-5 times to fully immerse the polypropylene spun-bond non-woven fabric.

[0040] Example Three

[0041] The magnetorheological fluid is prepared as in Example 1.

[0042] This example uses an extrusion damper, and the working interval is the gap between the upper and lower extrusion surfaces of the brake disc. The net fiber material used is polypropylene spun-bond non-woven fabric. The fixing means is physical fixing. Fixed grooves are opened on the side surfaces of the upper and lower extrusion surfaces.

[0043] As shown in Figure 3 The polypropylene spun-bond non-woven fabric is cut according to the surface pattern of the working interval, and sufficient length is reserved to cover the surface and the fixed groove. After sufficient stretching, the carbon fiber rope is wound on the fixed groove, and adhesive is dripped at the rope head to fix the rope head and prevent it from coming off. The carbon fiber rope is used to fix the polypropylene spun-bond non-woven fabric on the surface of the device

[0044] The device is immersed in a stearic acid solution to modify the polypropylene spun-bond non-woven fabric, and after ultrasonic dispersion, it is vacuum dried. Then it is repeatedly washed with anhydrous ethanol and dried to remove impurities.

[0045] The magnetorheological fluid is prepared by first modifying the magnetic particles, immersing them in an isopropyl alcohol solution for cleaning, stirring for 15 minutes, ultrasonic dispersion for 30 minutes, and finally drying in a vacuum drying oven below 60°C. Then 1% mass ratio of silane coupling agent, hexadecyl trimethyl silane is added to the base fluid, stirred uniformly and the treated magnetic particles are added, ultrasonic dispersion mixing is performed, and then the dispersed solution is placed in a ball mill for 10 hours to obtain the magnetorheological fluid.

[0046] The coated and cleaned brake disc is immersed in the magnetorheological fluid, immersed for 5 minutes, removed and placed in a vacuum drying oven at 60°C for vacuum drying for 30 minutes. This process is repeated 3-5 times to fully immerse the polypropylene spun-bond non-woven fabric.

[0047] Finally, it is to be explained that the above embodiments are only used to illustrate the technical solutions of the present application but not to limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalently replaced without departing from the purpose and scope of the present application, and all of them should be covered in the scope of the claims of the present application.

Claims

1. A magnetorheological fluid loaded damper, characterized in that: The invention comprises a composite working medium arranged in the working area of ​​the damper, wherein the composite working medium comprises a three-dimensional mesh fiber matrix and a magnetorheological fluid loaded on the three-dimensional mesh fiber matrix, and the magnetorheological fluid is in a semi-solid state on the three-dimensional mesh fiber matrix.

2. The magnetorheological fluid loaded damper according to claim 1, characterized in that: The magnetorheological fluid is loaded on the three-dimensional network fiber base by impregnation.

3. The magnetorheological fluid loaded damper according to claim 2, characterized in that: After the magnetorheological fluid fully permeates the three-dimensional network fibers, vacuum drying is performed until the three-dimensional network fibers completely lock the magnetorheological fluid.

4. The magnetorheological fluid loaded damper according to claim 3, characterized in that: Perform multiple soaking and drying cycles.

5. The magnetorheological fluid loaded damper according to claim 4, characterized in that: The drying temperature is 45-65℃.

6. The magnetorheological fluid loaded damper according to claim 2, characterized in that: The magnetorheological fluid includes a base liquid and magnetic particles, wherein the magnetic particles are dispersed and attached in the porous network structure of the three-dimensional network fiber material. The base liquid is bound to the three-dimensional network fiber material and allows the magnetic particles to move limitedly on the surface and inside of the three-dimensional network fiber material.

7. The magnetorheological fluid loaded damper according to claim 2, characterized in that: The three-dimensional mesh fiber is at least one of Kevlar, asbestos, polyethylene fiber, polypropylene fiber, cotton fabric, polyester, silk, and synthetic fiber.

8. The magnetorheological fluid loaded damper according to claim 1, characterized in that: The three-dimensional mesh fiber matrix is ​​arranged in the damper working area in a covering manner and a gap is reserved between the matrix and the corresponding working surface.

9. The magnetorheological fluid loaded damper according to claim 8, characterized in that: The gap between the three-dimensional mesh fiber matrix and the working surface is 0.1-0.5 mm.

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