A kind of active-passive cooperative magneto-rheological shear thickening fluid damper

Abstract

The application discloses a kind of active and passive synergic magnetorheological shear thickening fluid damper, including damper shell, the inner wall of the damper shell is slidably connected with piston, the outer periphery of the piston is integrated with adaptive cooperative sleeve, adaptive cooperative sleeve includes: one with excitation coil electrical connection sleeve base body, the base body has magnetism and conductivity;The outer wall of the sleeve base body is structured with multiple adaptive flow channel units extending along the axial direction, circumferentially spaced arrangement, the adaptive flow channel unit is formed by recess on the base body and the elastic filler body filled in the recess;The application belongs to damper technical field, reaches the technical effect for: by integrating conductive metal sleeve, rib and shell ring belt, and optimizing the wedge-shaped geometry of recess and block, the depth of synergic of multiple physical field energy dissipation mechanism is realized;When piston moves, rib and ring belt cut magnetic induction line and generate eddy current damping, provide a linearly related, wear-free additional passive energy dissipation with speed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of dampers, in particular to a main-passive cooperative magneto-rheological shear thickening fluid damper. BACKGROUND

[0002] In the field of modern civil engineering, bridge engineering and precision equipment vibration isolation, dampers as a key energy dissipation device play a crucial role in dissipating external vibration energy and ensuring structural safety and comfort. The damping characteristics of traditional passive dampers, such as viscous dampers, are fixed at the design stage and cannot be adjusted in real time according to the changes in external loads. Therefore, their damping efficiency is often limited when dealing with complex frequency spectrum and variable amplitude seismic or wind vibration loads. To overcome this shortcoming, intelligent fluid-based dampers have emerged. Among them, magneto-rheological fluid dampers can quickly and reversibly change their damping force by adjusting the external magnetic field, showing good semi-active control potential.

[0003] However, it completely depends on external power supply and control system, and once the power is lost, it will degenerate into a low damping state, which has safety hazards. On the other hand, shear thickening fluid dampers, as a pure passive device, can exhibit significant viscosity rise under high shear rate and have excellent passive energy dissipation capacity, but their characteristics cannot be adjusted in real time, and their response to low-frequency micro-vibration is weak. In recent years, some studies have attempted to combine magneto-rheological effect and shear thickening effect in order to obtain a composite intelligent fluid damper with adjustable and high energy dissipation potential.

[0004] However, most existing solutions simply mix the two fluids together and fail to achieve deep cooperation and complementarity of the two effects from the mechanical structure level of the damper, resulting in a simple addition of the characteristics of the two fluids and even mutual restriction of their performance. For example, the fixed fluid gap design makes it difficult to optimize the magnetic field distribution and flow field pattern, and the damper cannot adaptively adjust according to the impact strength. In extreme conditions, it may not have enough damping force or response lag, limiting the further improvement of its intelligent adaptability and reliability under wide frequency band and variable amplitude complex loads.

[0005] Therefore, the existing needs are not met, and to this end, we propose a main-passive cooperative magneto-rheological shear thickening fluid damper. SUMMARY

[0006] To this end, the present application provides a main-passive cooperative magneto-rheological shear thickening fluid damper to solve the above problems in the prior art.

[0007] To achieve the above purpose, the present application provides the following technical solutions:

[0008] According to a first aspect of the present application, an active-passive cooperative magneto-rheological shear thickening fluid damper comprises a damper shell, an inner wall of the damper shell being slidingly connected with a piston, a middle part of the piston being fixedly connected with a piston rod, an excitation coil being installed on the piston, an inside of the damper shell being filled with a magneto-rheological shear thickening fluid, an inner wall of the piston rod being provided with a wire channel, wires of the excitation coil passing through the channel and being led out to be connected with an external power supply; characterized in that an adaptive cooperative sleeve is integrated on an outer periphery of the piston, the adaptive cooperative sleeve comprising:

[0009] a sleeve-shaped base body electrically connected with the excitation coil, the base body having magnetic permeability and electrical conductivity;

[0010] an outer wall of the sleeve-shaped base body being configured with a plurality of adaptive flow channel units extending in an axial direction and being arranged in a circumferential direction at intervals, the adaptive flow channel units being composed of recesses formed on the base body and elastic filling bodies filled in the recesses;

[0011] wherein adjacent adaptive flow channel units form magnetic permeable ribs composed of sleeve-shaped base body material;

[0012] the elastic filling bodies being capable of elastically deforming towards the inside of the recess under the action of fluid pressure, so as to dynamically change the geometric shape and cross-sectional area of a fluid channel formed by the outer edges of adjacent magnetic permeable ribs, the surface of the elastic filling body and the inner wall of the damper shell;

[0013] the damper shell being provided with an inductive coupling part corresponding to the movement stroke of the piston.

[0014] Further, the sleeve-shaped base body is a metal sleeve fixedly sleeved on the outer wall of the piston, and is connected with the excitation coil through internal wires to form a current loop and a magnetic flux loop.

[0015] Further, the recess in the adaptive flow channel unit is a vertical groove formed on the outer wall of the sleeve-shaped base body, and the elastic filling body is a flexible sealing block embedded and fixed in the vertical groove.

[0016] Further, the thickness of the flexible sealing block is designed to decrease gradually from the root to the free end.

[0017] Further, the material of the flexible sealing block is polyurethane elastomer or silicone rubber elastomer.

[0018] Further, the vertical groove and the flexible sealing block inside it are both wedge-shaped in cross-sectional shape, with the width gradually decreasing from the inside to the outside.

[0019] Further, the magnetic permeable rib is an axially extending rib, which is part of the sleeve-shaped base body and has magnetic permeability and electrical conductivity.

[0020] Further, the inductive coupling part is an annular band inlaid and fixed to the inner wall of the damper shell, which is made of high-conductivity material.

[0021] Further, the elastic filling body deforms under fluid pressure, and simultaneously changes the distance between the outer edge of the magnetically permeable rib and the inductive coupling part, so as to adjust the magnetic coupling strength therebetween.

[0022] Further, the excitation coil is arranged around the inside of the piston.

[0023] Further, the metal sleeve is in interference fit or fixed by key connection between the piston body.

[0024] Further, the damper shell comprises a damper shell body, the two ends of the damper shell body are fixedly connected with a bushing one and a bushing two respectively, the end of the damper shell body away from the bushing one is fixedly connected with an extension pipe, one end of the piston rod is fixedly connected with a pin head one through the bushing one, the other end extends into the extension pipe through the bushing two, and the end of the extension pipe away from the damper shell body is fixedly installed with a pin head two.

[0025] The present application has the following advantages:

[0026] 1. The active-passive collaborative magneto-rheological shear thickening fluid damper introduces a metal sleeve electrically connected with the excitation coil and a rigid rib structure formed on the metal sleeve, so as to realize effective focusing and strengthening of the magnetic field. The design concentrates and guides the originally relatively uniformly dispersed magnetic field lines to the top of the rib, so as to form a local high magnetic flux density area between the rib and the shell or the annular band. This structural innovation significantly enhances the magneto-rheological effect in the key action area, so that a larger damping force adjustment can be realized with a smaller excitation current, greatly improving the energy efficiency and response sensitivity of the active control mode, and overcoming the disadvantages of low magnetic field utilization rate and low adjustment efficiency in the traditional structure.

[0027] 2. The active-passive collaborative magneto-rheological shear thickening fluid damper constructs an adaptive flow channel through the flexible sealing block arranged in the vertical groove of the metal sleeve and the gradient thickness design thereof. The flexible sealing block constitutes the dynamic boundary of the fluid channel, and its stress deformation is directly related to the external load intensity. Under low-frequency micro-amplitude vibration, it maintains the shape to maintain a narrow gap, optimizing the low-speed shear and magnetic field conditions. Under high-speed impact, it elastically bends to expand the flow channel, realizing instantaneous pressure relief and protection. This process simultaneously mechanically adjusts the magnetic pole gap, forming a negative feedback loop of "increased pressure → widened flow channel / increased magnetic gap → weakened magnetic field → more passive energy consumption". The adaptive ability and overall stability of the damper facing uncertain impact are significantly improved.

[0028] 3、The active-passive synergistic magnetorheological shear thickening fluid damper realizes deep synergy of multi-physical field energy dissipation mechanism through integration of the conductive metal sleeve, the rib and the shell ring belt, and optimization of the wedge-shaped geometry of the groove and the sealing block; when the piston moves, the rib and the ring belt cut the magnetic induction lines to generate eddy current damping, providing a linearly related speed, non-wearing additional passive energy dissipation, effectively filling the damping force saturation area that may occur at very high speed of the shear thickening fluid; at the same time, the wedge-shaped design not only guides the flow field to be smooth and improves the shear efficiency, but also makes the deformation of the flexible sealing block more controllable and the stress distribution more reasonable, further improving the linearity of the magnetic field adjustment feedback and the durability of the components; these structural measures make the shear thickening, magnetorheological and eddy current damping three effects no longer isolated, but interwoven and complementary in space and time, together extending the effective working frequency band of the damper to both high and low ends, ensuring efficient, smooth and reliable comprehensive shock absorption performance in the full working condition range from daily micro-vibration to extreme impact. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 A front view of a kind of active-passive synergistic magnetorheological shear thickening fluid damper proposed in the application;

[0030] Figure 2 A sectional view schematic diagram of Figure 1 ;

[0031] Figure 3 A front view of metal sleeve;

[0032] Figure 4 A exploded schematic diagram of Figure 3 ;

[0033] Figure 5 A front view sectional view of Figure 3 ;

[0034] Figure 6 A top view schematic diagram of piston in Figure 3 .

[0035] In the figure: 11, damper shell; 12, bushing one; 13, bushing two; 14, extension pipe; 15, piston rod; 16, pin head one; 17, pin head two; 18, excitation coil; 110, piston; 111, fluid gap; 21, metal sleeve; 22, vertical wedge-shaped groove; 23, flexible sealing block; 24, rib; 25, ring belt; DETAILED DESCRIPTION

[0036] The following embodiments will be described in greater detail by way of specific examples. As this technology is not a simple knowledge but a combination of multiple technical fields, other advantages and effects of the present application can be easily understood by those skilled in the art from the description. Obviously, the described embodiments are part of the embodiments of the present application, but not all. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0037] Embodiment one;

[0038] With reference to Figure 1 - Figure 3 A passive-active cooperative magneto-rheological shear thickening fluid damper, comprising a damper shell 11, the two ends of the damper shell 11 are respectively fixedly connected with a bushing one 12 and a bushing two 13 for plugging, the end of the damper shell 11 away from the bushing one 12 is fixedly connected with an extension pipe 14, the inner wall of the damper shell 11 is slidably connected with a piston 110, the middle part of the piston 110 is fixedly connected with a piston rod 15, one end of the piston rod 15 is fixedly connected with a pin head one 16 through the bushing one 12, the other end extends into the extension pipe 14 through the bushing two 13, the end of the extension pipe 14 away from the damper shell 11 is fixedly installed with a pin head two 17, there is an annular gap between the outer wall of the piston 110 and the inner wall of the damper shell 11, which is a fluid gap 111 for fluid flow, an excitation coil 18 is installed on the piston 110, the inner wall of the damper shell 11 is filled with magneto-rheological shear thickening fluid, a wire channel is arranged in the piston rod 15, the wires of the excitation coil 18 pass through the channel and are led out from the side wall of the piston rod 15 and connected with an external power supply;

[0039] Further, the magneto-rheological shear thickening fluid is a composite intelligent fluid composed of magneto-rheological material and shear thickening fluid; wherein the magneto-rheological material contains soft magnetic particles, carrier liquid and dispersant; the shear thickening fluid contains nano-sized particles and base carrier liquid; the composite material has both magneto-rheological properties and shear rate thickening properties;

[0040] Further, the excitation coil 18 is arranged in the inner cavity of the piston 110, and a controllable magnetic field can be formed in the fluid gap 111 around the piston 110 after the coil is energized; the direction of the magnetic field is basically perpendicular to the direction of the piston movement, so as to effectively act on the magneto-rheological shear thickening fluid in the gap;

[0041] In use, the damper is installed between the interlayer of a building structure or the pier of a bridge through the pin head 16 and the pin head 17 at both ends; when the piston rod 15 is subjected to external vibration or impact, the piston 110 reciprocates in the damper housing 11, pushing the magneto-rheological shear thickening fluid 19 to flow through the fluid gap 111; at this time, the damper can simultaneously exert passive and active damping effects: in the passive mode, the shear thickening fluid has a significant viscosity rise due to high-speed shearing, thereby dissipating energy; in the active mode, by controlling the current of the excitation coil 18 through an external power supply, the magnetic field strength can be adjusted in real time, so that the particles in the magneto-rheological fluid form a chain structure, further changing the fluid viscosity and damping characteristics; the two mechanisms work together to achieve a wide frequency, self-adaptive, and adjustable damping effect.

[0042] Working principle: the core of the damper is based on the composite intelligent fluid characteristics of magneto-rheological fluid and shear thickening fluid; in the absence of a magnetic field, the fluid mainly exhibits shear thickening behavior--as the piston movement speed increases, the shear rate of the fluid increases, resulting in a sharp increase in its apparent viscosity, producing a strong passive energy dissipation effect; when the excitation coil 18 is energized, a magnetic field perpendicular to the fluid flow direction is generated, and the magnetic particles in the magneto-rheological fluid align along the magnetic force lines to form a chain, increasing the fluid flow resistance; the active and passive effects are not simply superimposed, but are mutually enhanced under the cooperation of structural design and fluid: the magnetic field can regulate the critical shear rate of shear thickening, while shear flow also affects the formation and destruction rate of the magneto-rheological structure, thereby achieving more rapid, more stable, and larger range of damping force adjustment in a wide frequency vibration range.

[0043] Example two:

[0044] The example one is basically the same, however, the piston structure in the example one is relatively simple, its fluid gap is fixed, resulting in a relatively uniform but not focused magnetic field distribution, and in extreme working conditions (such as ultra-high speed impact or low frequency micro-vibration), the adaptive adjustment capability is limited, further more: Figure 1 Figure 6 A kind of active and passive cooperative magneto-rheological shear thickening fluid damper, a metal sleeve 21 is fixedly sleeved on the outer periphery of the piston 110; the metal sleeve 21 is made of a material with good magnetic conductivity and electrical conductivity (such as silicon steel treated with surface conduction), and is electrically connected with the excitation coil 18 through internal circuit, so that it can act as a part of the magnetic circuit (pole shoe) and carry current when energized;

[0045] ​The outer wall of the metal sleeve 21 is uniformly provided with a plurality of axially extending vertical grooves 22 in the circumferential direction; each of the vertical grooves 22 is provided with a flexible sealing block 23; the root of the flexible sealing block 23 (i.e. the side close to the center of the piston 110) is fixedly connected with the groove bottom of the vertical groove 22, and the thickness is designed to be gradually decreased from inside to outside (i.e. from the root to the free end), so that the rigidity of the flexible sealing block 23 gradually decreases from inside to outside (the material of the flexible sealing block 23 can be high-performance polyurethane or silicone rubber elastomer, which has the characteristics of high elasticity, fatigue resistance and compatibility with working fluid); by providing these vertical grooves 22, the solid part of the metal sleeve 21 naturally forms a plurality of axially extending, magnetically conductive and conductive rigid ribs 24 between adjacent grooves; in addition, a ring belt 25 made of high-conductive and magnetically conductive material (such as copper or aluminum alloy) is embedded and fixed on the inner wall of the damper housing 11 corresponding to the movement stroke of the piston 110;

[0046] Working principle: by integrating the metal sleeve 21, the flexible sealing block 23 and the conductive ring belt 25, a composite intelligent piston system integrating magnetic field focusing, flow channel self-adaptation and eddy current damping is constructed; its working principle and the resulting synergistic effect are as follows:

[0047] When the exciting coil 18 is energized, the current flows through the metal sleeve 21; since the metal sleeve 21 is made of magnetically conductive material, the rigid ribs 24 thereon become efficient magnetic poles, which can concentrate and direct the magnetic field lines generated by the exciting coil 18 outward, forming a high-strength, localized magnetic field region between the top end of the rib 24 and the damper housing 11; compared with the relatively uniform magnetic field in the first embodiment, this significantly improves the magnetic flux density in the key area of the fluid gap 111, making the magneto-rheological effect more sensitive and efficient, so that stronger active adjustment capability can be achieved with smaller current;

[0048] The flexible sealing block 23 constitutes a variable boundary when the fluid flows through the piston 110; when the piston 110 moves at a low speed or the fluid pressure is low, the flexible sealing block 23 maintains its original shape due to its elasticity, together with the outer edge of the rigid rib 24, forming a relatively narrow flow channel, which is beneficial to generating sufficient shear at low speed to start passive energy dissipation and maintaining a small magnetic gap to enhance the magnetic field; when encountering high-speed impact or a dramatic increase in fluid pressure, the high-pressure fluid acts on the inclined surface of the flexible sealing block 23, forcing it to elastically deform and bend into the vertical groove; this instantly increases the cross section of the flow channel, achieving a double effect: first, as a pressure relief valve, to avoid excessive peak damping force and protect the mechanical structure; second, it automatically adjusts the gap between the magnetic pole (top end of the rib 24) and the opposite conductive ring belt 25; the greater the pressure, the greater the gap, and the magnetic field is correspondingly weakened, which forms a kind of purely mechanical negative feedback regulation, making the system more dependent on passive energy dissipation under high load and automatically optimizing the magnetic field conditions when fine adjustment is required;

[0049] When the piston 110 moves at high speed, the magnetically and electrically conductive metal sleeve 21 (especially the rib 24 part) moves relative to the ring belt 25 embedded on the damper shell 11; even without an external excitation current, the weak magnetic leakage of the excitation coil 18 will be cut by the rib 24, thereby inducing eddy currents in the conductive ring belt 25; this eddy current will generate a damping force that is always opposite to the direction of motion of the piston 110; this mechanism provides additional damping force that is completely passive, contactless and wearless, and its size is proportional to the speed of the piston 110; it effectively compensates for the possible damping force saturation or plateau effect of the magnetorheological shear thickening fluid at very high speed, and widens the high-frequency and high-efficiency working range of the damper;

[0050] Embodiment three:

[0051] Basically the same as embodiment two, in order to further optimize the flow field shape, improve the controllability of flexible sealing block deformation and the synergistic efficiency with the magnetic field, the vertical groove and the geometric configuration of the flexible sealing block are finely designed in this embodiment; further, referring to Figure 1 Figure 6 A kind of active and passive synergistic magnetorheological shear thickening fluid damper, the vertical groove 22 on the outer wall of the metal sleeve 21 and the flexible sealing block 23 embedded therein, its cross-sectional shape is designed as wedge shape gradually decreasing from inside to outside (i.e. from the bottom of the slot to the opening direction).

[0052] Working principle: this wedge design is not a simple shape change, its core improvement principle is as follows:

[0053] The wedge-shaped vertical groove 22 and the flexible sealing block 23 together form a flow passage with a smooth change in cross-sectional area along the flow direction (radial direction); when the piston moves, the fluid enters this wedge-shaped gap and will produce a controllable acceleration or deceleration effect due to the change in flow cross section;

[0054] The wedge-shaped structure with decreasing width means that the material width of the root of the flexible sealing block 23 is the largest, and gradually narrows to the free end; this geometric feature brings two key improvements:

[0055] 1. The wider root provides stable support and greater initial stiffness, while the narrower tip makes it easier to deform elastically under fluid pressure, mainly bending and more directional;

[0056] 2. The wedge-shaped structure is beneficial to smoothly transfer and disperse stress from the wide root to the narrow free end, avoiding the sharp concentration of stress in the local (especially the root fixed part); combined with the gradient thickness design (thickness also decreases from inside to outside) described in embodiment two, the fatigue resistance and service life of the flexible sealing block 23 under long-term and repeated deformation are further improved.​

Claims

1. An active-passive cooperative magneto-rheological shear thickening fluid damper, comprising a damper shell, an inner wall of the damper shell being slidingly connected with a piston, a middle portion of the piston being fixedly connected with a piston rod, the piston being provided with an exciting coil, an inside of the damper shell being filled with a magneto-rheological shear thickening fluid, an inner wall of the piston rod being provided with a wire channel, wires of the exciting coil passing through the channel and being led out to be connected with an external power supply; characterized in that, The outer periphery of the piston is integrated with an adaptive sleeve, which comprises: a sleeve-shaped base body electrically connected with the excitation coil, the base body having both magnetic permeability and electrical conductivity; the outer wall of the sleeve-shaped base body is configured with a plurality of adaptive flow channel units extending in the axial direction and arranged in a circumferential interval, the adaptive flow channel units being composed of a recess formed on the base body and an elastic filler body filled in the recess; wherein the adaptive flow channel units adjacent to each other form a magnetic permeable rib composed of the material of the sleeve-shaped base body; the elastic filler body can elastically deform towards the inside of the recess under the action of fluid pressure, thereby dynamically changing the geometric shape and cross-sectional area of the fluid passage jointly formed by the outer edges of the adjacent magnetic permeable ribs, the surface of the elastic filler body and the inner wall of the damper housing; the region of the inner wall of the damper housing corresponding to the movement stroke of the piston is provided with an inductive coupling part.

2. The passive and active cooperative magneto-rheological shear thickening fluid damper according to claim 1, characterized in that, The sleeve-shaped base body is a metal sleeve fixedly sleeved on the outer wall of the piston, which is connected with the excitation coil through internal wires to form a current loop and a magnetic flux loop.

3. The passive and active cooperative magnetorheological shear thickening fluid damper according to claim 2, characterized in that, The recess in the adaptive flow channel unit is a vertical groove formed on the outer wall of the sleeve-shaped base body, and the elastic filler body is a flexible block embedded and fixed in the vertical groove.

4. The passive and active cooperative magnetorheological shear thickening fluid damper according to claim 3, characterized in that, The thickness of the flexible block is designed to decrease gradually from the root to the free end.

5. The passive and active cooperative magnetorheological shear thickening fluid damper according to claim 4, characterized in that, The material of the flexible block is polyurethane elastomer or silicone rubber elastomer.

6. The passive and active cooperative magneto-rheological shear thickening fluid damper according to claim 5, wherein, The cross-sectional shape of the vertical groove and the flexible block inside it is wedge-shaped, with the width gradually decreasing from the inside to the outside.

7. The passive and active cooperative magneto-rheological shear thickening fluid damper according to claim 6, characterized in that, The magnetic permeable rib is an axially extending rib, which is part of the sleeve-shaped base body and has both magnetic permeability and electrical conductivity.

8. The passive and active cooperative magneto-rheological shear thickening fluid damper according to claim 7, characterized in that, The inductive coupling part is a ring band inlaid and fixed on the inner wall of the damper housing, which is made of high-conductive material.

9. The passive and active cooperative magnetorheological shear thickening fluid damper according to claim 1, wherein, The deformation of the elastic filler body under fluid pressure simultaneously changes the distance between the outer edge of the magnetic permeable rib and the inductive coupling part, thereby adjusting the magnetic coupling strength between the two.

10. The passive and active cooperative magnetorheological shear thickening fluid damper according to claim 2, wherein, The excitation coil is arranged around the inside of the piston.

11. The passive and active cooperative magneto-rheological shear thickening fluid damper according to claim 10, wherein, The metal sleeve and the piston body are in interference fit or fixed by key connection.

12. The passive and active cooperative magnetorheological shear thickening fluid damper according to claim 1, wherein, The damper housing comprises a damper housing, the two ends of the damper housing are fixedly connected with a bushing one and a bushing two, the end of the damper housing away from the bushing one is fixedly connected with an extension pipe, one end of the piston rod is fixedly connected with a pin head one through the bushing one, the other end extends into the extension pipe through the bushing two, and the end of the extension pipe away from the damper housing is fixedly installed with a pin head two.

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