Adjustable swing gap passive magnetorheological damper

Abstract

This invention provides a passive magnetorheological damper with adjustable swing gap, comprising a cylinder, a piston rod, and a piston assembly. The cylinder includes a cylinder barrel with openings at both ends along the axial direction and end caps respectively connected to the openings of the cylinder barrel. The piston assembly is slidably disposed within the cylinder barrel. The connecting end of the piston rod is connected to the piston assembly, and the free end of the piston rod extends axially through the end caps. The piston assembly includes a piston end cap and several damping components distributed circumferentially on the piston end cap. The connecting ends of the damping components are hinged to the piston end caps, and the free ends of the damping components can be driven to move away from the inner wall of the cylinder barrel. The invention also includes an adjustment component disposed within the cylinder barrel, which drives the free ends of the damping components to swing away from the inner wall of the cylinder barrel around the hinge point. This damper requires no external power supply or sealing element, has a mechanically adjustable swing gap, a compact structure, and a large output damping force, which is beneficial for the further promotion and application of magnetorheological technology.

Description

Technical Field

[0001] This invention relates to the field of magnetorheological vibration reduction technology, and in particular to a passive magnetorheological damper with adjustable swing gap. Background Technology

[0002] In commonly used mechanical equipment, various moving parts often lead to various vibration problems, which can cause serious failure and damage to the equipment. Magnetorheological dampers are a new type of damper that replaces part or all of the energy-consuming medium with magnetorheological materials. They have advantages such as low energy consumption, fast response, and continuously adjustable damping. They have been widely used in vibration suppression fields such as automotive vibration reduction, building vibration isolation, and aircraft vibration control systems, and have good development prospects.

[0003] Currently, most conventional magnetorheological dampers incorporate an internal excitation coil. The strength of the magnetic field is altered by changing the current flowing through the coil, thereby changing the properties of the magnetorheological material and controlling the damper's output force. However, in certain special environments, it is often difficult or impossible to provide the power required to control the magnetorheological damper. This forces conventional magnetorheological dampers to operate in a passive state, with no control over the output force. Furthermore, the excitation coil is prone to short circuits or open circuits during actual use. With prolonged input of operating current, the damper's internal structure overheats significantly, leading to a substantial decrease in performance. In addition, conventional magnetorheological dampers often use magnetorheological fluid as their working medium, which places high demands on the damper's sealing performance. The poor durability of magnetorheological fluids and the tendency for internal ferromagnetic particles to settle further contribute to a decline in the damper's mechanical properties.

[0004] Therefore, in order to solve the problems of conventional magnetorheological dampers, such as the need for an external power supply, severe heating during use, easy leakage of magnetorheological fluid and particle sedimentation, and based on magnetorheological composite materials and shear working mode, a passive magnetorheological damper with adjustable swing gap is proposed. Summary of the Invention

[0005] In view of this, this invention proposes a passive magnetorheological damper with adjustable swing gap based on magnetorheological composite materials and shear working mode. The purpose is to solve the problems of conventional magnetorheological dampers, such as the need for an external power supply, severe heating during use, easy leakage of magnetorheological fluid, and particle sedimentation. This damper does not require an external power supply or sealing elements, the swing gap is mechanically adjustable, the structure is compact, and the output damping force is large, which is conducive to the further promotion and application of magnetorheological technology.

[0006] The present invention addresses the aforementioned problem through the following technical solution:

[0007] An adjustable swing gap passive magnetorheological damper includes a cylinder, a piston rod, and a piston assembly. The cylinder includes a cylinder barrel with openings at both ends along the axial direction and end caps respectively connected to the openings of the cylinder barrel. The piston assembly is slidably disposed within the cylinder barrel. The connecting end of the piston rod is connected to the piston assembly, and the free end of the piston rod extends axially through the end caps. The piston assembly includes a piston end cap disposed at the connecting end of the piston rod and a plurality of damping assemblies distributed circumferentially on the piston end caps. The damping assemblies are used to cooperate with the inner wall of the cylinder barrel to output damping force when the piston assembly slides. The connecting end of the damping assembly is hinged to the piston end cap, and the free end of the damping assembly can be driven to move away from the inner wall of the cylinder barrel.

[0008] It also includes an adjustment component disposed inside the cylinder, the adjustment component being used to drive the free end of the damping component to swing around the hinge point in a direction away from the inner wall of the cylinder to adjust the size of the gap between the damping component and the inner wall of the cylinder.

[0009] Furthermore, the damping component includes a magnet and a magnetorheological composite material. The magnet is used to provide an excitation magnetic field for the magnetorheological composite material. The magnetorheological composite material is located between the magnet and the inner wall of the cylinder and can generate a damping force for the relative sliding of the piston assembly under the action of the excitation magnetic field.

[0010] Furthermore, the magnet includes a magnetic conductive tile and a sector-shaped magnetic tile. The connecting end of the magnetic conductive tile is hinged to the piston end cap via a pin. The sector-shaped magnetic tile is disposed on the outer surface of the magnetic conductive tile, and the magnetorheological composite material is disposed on the outer surface of the sector-shaped magnetic tile.

[0011] Furthermore, the sector-shaped magnetic tiles are formed by radially outward magnetization to form outwardly magnetized sector-shaped magnetic tiles or by radially inward magnetization to form inwardly magnetized sector-shaped magnetic tiles. Multiple outwardly magnetized sector-shaped magnetic tiles and multiple inwardly magnetized sector-shaped magnetic tiles are arranged alternately to form an excitation magnetic field perpendicular to the magnetorheological composite material in the radial direction.

[0012] Furthermore, the piston end cap is also provided with a fixed sleeve inside the damping assembly. The adjusting assembly includes a lead screw that can rotate around its own axis, an adjusting shaft for driving the lead screw to rotate, and a lead screw sleeve sleeved on the lead screw. One end of the lead screw is located inside the fixed sleeve and a support bearing is provided between it and the inner wall of the fixed sleeve, and a rotational fit is formed through the support bearing. The other end of the lead screw extends out of the fixed sleeve and has a threaded section on the outer side of the end. The lead screw sleeve is sleeved on the threaded section and threadedly connected to the lead screw.

[0013] The lead screw is a hollow tubular rod with an internal spline. The connection end of the adjusting shaft to the lead screw is provided with an external spline. The connection end of the adjusting shaft to the lead screw is inserted into the lead screw and connected to the internal spline inside the lead screw through the external spline for transmission.

[0014] Furthermore, the free end of the magnetic conductive tile is provided with an outer conical top block with the working end facing inward, and the outer surface of the lead screw sleeve is provided with a plurality of inner conical top cones along the circumferential direction for cooperating with the outer conical top block. The inner conical top cones and the outer conical top block are driven by line contact formed by the inner and outer conical surfaces.

[0015] When the lead screw is driven to rotate around its own axis, the lead screw sleeve moves linearly on the threaded section of the lead screw, and the top cone of the inner conical hole makes line contact with the top block of the outer conical surface on the magnetic bearing, so as to drive the free end of the magnetic bearing to swing around the hinge point in a direction away from the inner wall of the cylinder.

[0016] Furthermore, the adjustment assembly also includes an adjustment wrench perpendicular to the adjustment shaft. The adjustment end of the adjustment wrench extends out of the sleeve through the adjustment hole. The adjustment hole is a strip-shaped hole opened circumferentially on the sleeve. By turning the adjustment wrench along the adjustment hole, the rotation of the adjustment shaft is driven, thereby rotating the lead screw.

[0017] Furthermore, the adjustment assembly includes a sliding sleeve sleeved on the piston rod and an adjustment wrench for driving the sliding sleeve to make linear displacement on the piston rod. The free end of the piston rod is provided with a threaded section. The adjustment wrench is perpendicular to the piston rod and threadedly engaged with the threaded section. The free end of the magnetic conductive tile extends outward along the axial direction to form an outer conical surface. The sliding sleeve is recessed inward along the axial direction at the end that engages with the magnetic conductive tile to form an inner conical surface that is in line contact with the outer conical surface.

[0018] By moving the adjusting wrench along the threaded section of the piston rod in a linear motion, the movable sleeve is driven to move along the piston rod toward the interior of the cylinder, thereby making the inner conical surface of the sliding sleeve in line contact with the outer conical surface of the magnetic bearing, thus driving the free end of the magnetic bearing to swing away from the inner wall of the cylinder around the hinge point.

[0019] Furthermore, a return spring is provided between the magnetic conductive tile and the piston rod, and the return spring is used to provide a restoring force for the magnetic conductive tile to reset.

[0020] Furthermore, a guide member is provided between the end cap and the piston rod, and the guide member is used together with the end cap to guide and support the piston rod;

[0021] A lifting lug is fixedly provided at the free end of the piston rod, and a lifting lug is fixedly provided on the outside of the end cap opposite to the piston rod extending out of the cylinder.

[0022] The beneficial effects of this invention are:

[0023] 1) The adjustable swing gap passive magnetorheological damper of the present invention generates a working magnetic field by using a permanent magnet instead of an energized coil. It has a relatively simple structure, is suitable for long-term operation, and has low energy consumption.

[0024] 2) This invention improves the magnetorheological effect by immersing nonwoven fabric in magnetorheological fluid to prepare magnetorheological composite material, and attaches the magnetorheological composite material to the outer surface of the fan-shaped magnetic tile, which greatly increases the shear area of ​​the magnetorheological material and increases the output damping force.

[0025] 3) The output damping force of the swing gap adjustable passive magnetorheological damper in this invention is mechanically adjustable. By turning the adjustment wrench, the swing gap between the swing component and the inner wall of the cylinder can be adjusted, thereby changing the magnetic field strength and effective volume of the magnetorheological composite material in the working area, thus realizing the mechanically adjustable damping characteristics.

[0026] 4) The magnetorheological composite material in this invention simplifies the sealing structure of the damper by using a non-woven fabric as the matrix instead of the traditional magnetorheological liquid medium. At the same time, the magnetorheological composite material has good anti-settling performance. Attached Figure Description

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] Figure 1 This is a schematic diagram of the overall structure of the adjustable swing gap passive magnetorheological damper in this invention.

[0029] Figure 2 for Figure 1 Enlarged view of a portion of the structure;

[0030] Figure 3 for Figure 2 AA cross-section view;

[0031] Figure 4 This is a schematic diagram illustrating the working principle of the swing gap adjustment in this invention;

[0032] Figure 5 This is a supplementary description of the piston assembly in this invention;

[0033] Figure 6 This is an overall schematic diagram of the second structure in this invention;

[0034] Figure 7This is a schematic diagram illustrating the working principle of the second structure in this invention;

[0035] Figure 8 This is a supplementary description of the second type of piston assembly in this invention;

[0036] The attached figures are labeled as follows: 1-Left lifting lug, 2-Piston rod, 3-Left end cap, 4-Cylinder, 5-Pin, 6-Magnetic guide tile, 7-Fan-shaped magnetic tile, 8-Magnetorheological composite material, 9-Inner conical hole top cone, 10-Outer conical surface top block, 11-Adjusting wrench, 12-Right end cap, 13-Adjusting shaft, 14-Screw sleeve, 15-Right end cap of fixed sleeve, 16-Fixed sleeve, 17-Screw, 19-Guide component, 21-Piston end cap, 22-Reset spring, 23-Sliding sleeve, 24-Adjusting nut, 701-Outwardly magnetized fan-shaped magnetic tile, 702-Inwardly magnetized fan-shaped magnetic tile. Detailed Implementation

[0037] As shown in the figure, the present invention provides a passive magnetorheological damper with adjustable swing gap, comprising a cylinder, a piston rod 2, and a piston assembly. The cylinder includes a cylinder 4 with openings at both ends along the axial direction and end caps respectively connected to the openings of the cylinder 4. The piston assembly is slidably disposed within the cylinder 4. The connecting end of the piston rod 2 is connected to the piston assembly, and the free end of the piston rod 2 extends axially through the end cap. The piston assembly includes a piston end cap 21 disposed at the connecting end of the piston rod 2 and a plurality of damping components distributed circumferentially on the piston end cap 21. The damping components are used to cooperate with the inner wall of the cylinder 4 to output damping force when the piston assembly slides. The connecting end of the damping component is hinged to the piston end cap 21, and the free end of the damping component can be driven to move away from the inner wall of the cylinder.

[0038] It also includes an adjustment component disposed within the cylinder 4, the adjustment component being used to drive the free end of the damping component to swing around the hinge point in a direction away from the inner wall of the cylinder to adjust the size of the gap between the damping component and the inner wall of the cylinder.

[0039] In this embodiment, the cylinder body mainly consists of a cylinder 4 with openings at both ends along the axial direction, a left end cap 3 connected to the left opening of the cylinder 4, and a right end cap 12 connected to the right opening of the cylinder 4. The left end cap 3 and the right end cap 12 are both threadedly connected to the cylinder 4. The piston assembly includes a piston end cap 21 disposed at the connecting end of the piston rod 2 and several damping components distributed circumferentially on the piston end cap 21. Several damping components are distributed circumferentially on the piston end cap 21, which are mainly used to output damping force when the piston assembly is driven to slide and cooperate with the inner wall of the cylinder 4. The connecting end of the damping component is hinged to the piston end cap 21, and the free end of the damping component can be driven to move away from the inner wall of the cylinder to change the size of the gap between the damping component and the inner wall of the cylinder 4. The adjusting component is disposed inside the cylinder 4 and is mainly used to drive the free end of the damping component to swing around the hinge point away from the inner wall of the cylinder to adjust and change the size of the gap between the damping component and the inner wall of the cylinder 4, thereby realizing the adjustment of the damping force.

[0040] In this embodiment, the damping component includes a magnet and a magnetorheological composite material 8. The magnet provides an excitation magnetic field to the magnetorheological composite material 8. The magnetorheological composite material 8 is located between the magnet and the inner wall of the cylinder and, under the action of the excitation magnetic field, can generate a damping force for the relative sliding of the piston assembly. Figure 1 and Figure 6 As shown, the damping component includes a magnet and a magnetorheological composite material 8. Traditional magnetorheological dampers require an external power supply and adjust the strength of the working magnetic field by changing the current flowing through the coil, thereby adjusting the magnitude of the magnetorheological damping force. This application, however, uses a magnetized magnet to generate the excitation magnetic field, eliminating the need for an external power supply and making it more energy-efficient. The magnetorheological composite material 8 is a novel material prepared by immersing a non-woven fabric matrix in a magnetorheological fluid. By using the magnetorheological composite material 8 instead of the traditional magnetorheological fluid medium, the damper no longer requires a dedicated sealing structure, simplifying the overall structure. Furthermore, the magnetorheological composite material 8 exhibits good anti-settling properties. Additionally, by using a permanent magnet instead of an energized coil to generate the working magnetic field, the overall structure of the damper is relatively simple, suitable for long-term operation, and consumes less energy.

[0041] In this embodiment, the magnet includes a magnetic conductive tile 6 and a fan-shaped magnetic tile 7. The connecting end of the magnetic conductive tile 6 is hinged to the piston end cap 21 via a pin 5. The fan-shaped magnetic tile 7 is disposed on the outer surface of the magnetic conductive tile 6, and the magnetorheological composite material 8 is disposed on the outer surface of the fan-shaped magnetic tile 7. The magnet mainly includes a magnetic conductive tile 6 and a fan-shaped magnetic tile 7. Both the magnetic conductive tile 6 and the fan-shaped magnetic tile 7 are made into a split structure. The connecting end of the magnetic conductive tile 6 is generally hinged to the piston end cap 21 via a pin 5 to perform swinging motion. The specific structure of the magnetic conductive tile 6 and the fan-shaped magnetic tile 7, as well as the connection method between the magnetic conductive tile 6 and the fan-shaped magnetic tile 7, can be designed according to the actual situation. Figures 1-5In the first magnetorheological damper structure disclosed herein, the magnetic conductive tile 6 and the sector-shaped magnetic tile 7 are connected by a slot structure, while the magnetorheological composite material 8 is fixed to the outside of the sector-shaped magnetic tile 7 by an adhesive and covers the outside of the sector-shaped magnetic tile 7. Figures 6-8 In the second magnetorheological damper structure disclosed herein, the sector-shaped magnetic tile 7 and the magnetic conductive tile 6 are connected by screws; by attaching the magnetorheological composite material 8 to the outer surface of the sector-shaped magnetic tile 7, the gap between the composite material and the inner wall of the cylinder 4 forms an annular working area, which greatly increases the shear area of ​​the magnetorheological composite material, thereby increasing the output damping force.

[0042] In this embodiment, the sector-shaped magnetic tiles 7 are formed by radially outward magnetization to create outwardly magnetized sector-shaped magnetic tiles 701 or by radially inward magnetization to create inwardly magnetized sector-shaped magnetic tiles 702. Multiple outwardly magnetized sector-shaped magnetic tiles 701 and multiple inwardly magnetized sector-shaped magnetic tiles 702 are arranged alternately to form an excitation magnetic field perpendicular to the magnetorheological composite material 8 in the radial direction. In this technical solution, the cylinder 4 and the magnetic conductive tile 6 are made of magnetically conductive material, while the sector-shaped magnetic tiles 7 are made of magnetized material, thus forming a stable excitation working magnetic field. Figure 3 As shown, an even number of magnetic conductive tiles 6 and sector-shaped magnetic tiles 7 are selected. First, half of the sector-shaped magnetic tiles 7 are magnetized radially outward to form outwardly magnetized sector-shaped magnetic tiles 701. Then, the other half of the sector-shaped magnetic tiles 7 are magnetized radially inward to form inwardly magnetized sector-shaped magnetic tiles 702. Finally, the outwardly magnetized sector-shaped magnetic tiles 701 and the inwardly magnetized sector-shaped magnetic tiles 702 are arranged alternately to obtain an excitation magnetic field perpendicular to the magnetorheological composite material 8 in the radial direction, so as to act on the magnetorheological composite material 8.

[0043] In the first magnetorheological damper structure of this embodiment, the piston end cap 21 is further provided with a fixed sleeve 16 inside the damping assembly. The adjusting assembly includes a lead screw 17 rotatable about its own axis, an adjusting shaft 13 for driving the lead screw to rotate, and a lead screw sleeve 14 sleeved on the lead screw. One end of the lead screw 17 is located inside the fixed sleeve 16 and a support bearing is provided between it and the inner wall of the fixed sleeve 16, forming a rotational fit through the support bearing. The other end of the lead screw 17 extends out of the fixed sleeve 16 and has a threaded section on the outer side of the end. The lead screw sleeve 14 is sleeved on the threaded section and screwed with the lead screw 17. The screw rod 17 is axially fixed to the piston end cap 21 and arranged inside the damping assembly. At this time, the piston end cap 21 serves as the left end cap of the fixed sleeve 16, while the right end opening of the fixed sleeve 16 is provided with a right end cap 15. The fixed sleeve 16 and the piston end cap 21 are positioned by cylindrical surfaces and fastened with screws, and the right end cap 15 and the fixed sleeve 16 are also positioned by cylindrical surfaces and fastened with screws. Several support bearings are provided inside the fixed sleeve 16, and the screw rod 17 can rotate around its own axis inside the fixed sleeve 16 through the support bearings. The screw rod sleeve 14 and the threaded section of the screw rod 17 are connected by threads to form a helical pair.

[0044] The lead screw 17 is a hollow tubular rod with an internal spline. The connection end of the adjusting shaft 13 and the lead screw 17 is provided with an external spline. The connection end of the adjusting shaft 13 and the lead screw 17 is inserted into the lead screw 17 and connected to the internal spline inside the lead screw 17 through the external spline for transmission.

[0045] In the first magnetorheological damper structure of this embodiment, the free end of the magnetic conductive tile 6 is provided with an outer conical top block 10 with the working end arranged inward. The outer surface of the lead screw sleeve 14 is provided with a plurality of inner conical top cones 9 arranged circumferentially for cooperating with the outer conical top block. The inner conical top cones 9 and the outer conical top block 10 are driven by line contact formed by the inner and outer conical surfaces. The outer conical top block 10 and the free end of the magnetic conductive tile 6 are connected and fixed by screws, while the inner conical top cones 9 are welded to the outer surface of the lead screw sleeve 14.

[0046] When the lead screw 17 is driven to rotate around its own axis, the lead screw sleeve 14 moves linearly on the threaded section of the lead screw 17, and makes the top cone 9 of the inner conical hole make line contact with the top block 10 of the outer conical surface on the magnetic guide tile 6, so as to drive the free end of the magnetic guide tile 6 to swing around the hinge point in a direction away from the inner wall of the cylinder 4. It can be seen that the variable damping characteristics of the damper are realized by adjusting the swing gap. While adjusting the swing gap, the magnetic attraction generated between the damping component and the cylinder 4 is also overcome.

[0047] In the first magnetorheological damper structure of this embodiment, the adjustment assembly further includes an adjustment wrench 11 that is perpendicular to the adjustment shaft. The connecting section of the adjustment wrench 11 is welded to the adjustment shaft 13, and the adjustment end of the adjustment wrench 11 extends out of the cylinder 4 through the adjustment hole. The adjustment hole is a strip-shaped hole opened circumferentially on the sleeve 4. By turning the adjustment wrench 11 along the adjustment hole, the rotation of the adjustment shaft 13 is driven, thereby realizing the rotation of the lead screw 17.

[0048] In the first magnetorheological damper structure of this embodiment, combined with... Figures 1 to 5 As shown, the basic principle of generating damping force is as follows: Under the working magnetic field generated by the sector-shaped magnetic tile 7 and passing through the magnetorheological composite material 8, the magnetorheological composite material 8 transforms into a high-viscosity solid-like substance. The working area is formed by the magnetorheological composite material 8 and the inner wall of the cylinder 4, and a certain damping force is generated through the shear-type working mode. Usually, when the input speed of the damper remains constant, the damping force generated by the damper is related to the gap at the working area.

[0049] The working principle of the first type of magnetorheological damper swing clearance adjustment is as follows: Rotating the adjusting wrench 11 drives the adjusting shaft 13, which is connected to the lead screw 17 via a spline, causing the lead screw 17 to rotate. The helical pair composed of the lead screw sleeve 14 and the lead screw 17 drives the lead screw sleeve 14 to move axially on the threaded surface of the lead screw 17. The inner conical surface of the top cone 9 of the inner conical hole forms a line contact with the outer conical surface of the top block 10 of the outer conical surface, preventing the magnetic attraction force generated by the fan-shaped magnetic tile 7 and the inner wall of the cylinder 4 from causing the working clearance adjustment to be uncontrollable. The axial movement of the top cone 9 of the inner conical hole causes the swing assembly to rotate around the axis of the shaft pin 5, thereby reducing the working clearance between the swing assembly and the inner wall of the cylinder 4. This changes the magnetic field strength and effective volume of the magnetorheological composite material 8 in the working area. At the same time, the effective working area formed by the magnetorheological composite material 8 and the inner wall of the cylinder 4 will be reduced accordingly, realizing the adjustable damping mechanical characteristics of the damper.

[0050] In the second magnetorheological damper structure of this embodiment, the adjustment assembly includes a sliding sleeve 23 sleeved on the piston rod and an adjustment wrench 11 for driving the sliding sleeve 23 to make linear displacement on the piston rod 2. The free end of the piston rod 2 is provided with a threaded section. The adjustment wrench 11 is perpendicular to the piston rod 2 and is threadedly engaged with the threaded section. The free end of the magnetic conductive tile 6 extends outward along the axial direction to form an outer conical surface. The sliding sleeve 23 is recessed inward along the axial direction at the end that engages with the magnetic conductive tile 6 to form an inner conical surface that is in line contact with the outer conical surface. The adjustment wrench 11 is welded to the adjustment nut 24. The adjustment nut 24 and the piston rod 2 are connected by threads to form a helical pair. The sliding sleeve 23 is arranged on the sliding surface of the piston rod 2 and its axial movement is restricted by a boss. The inner conical surface of the sliding sleeve 23 forms a line contact with the outer conical surface of the magnetic conductive tile 6, so that it can overcome the magnetic attraction between the fan-shaped magnetic tile 7 and the cylinder 4, thereby adjusting the swing gap.

[0051] By moving the adjusting wrench 11 linearly along the threaded section of the piston rod 2, the movable sleeve 23 is driven to slide along the piston rod 2 toward the interior of the cylinder 4, thereby making the inner conical surface of the sliding sleeve 23 in line contact with the outer conical surface of the magnetic guide tile 6, so as to drive the free end of the magnetic guide tile 6 to swing away from the inner wall of the cylinder 4 around the hinge point.

[0052] In the second magnetorheological damper structure of this embodiment, a return spring 22 is further provided between the magnetic conductive tile 6 and the piston rod 2. The return spring 22 is used to provide a restoring force to the magnetic conductive tile 6 for reset; combined with Figure 6 and Figure 7 As shown, the return spring 2 is fixed in the groove formed by the magnetic tile 6 and the piston rod 2. Since the adjustment component can only be used to drive the free end of the magnetic tile 6 to swing away from the inner wall of the cylinder 4 around the hinge point, it cannot provide a force for the return of the magnetic tile 6. Therefore, a return spring 22 is provided between the magnetic tile 6 and the piston rod 2 to provide an appropriate rebound force.

[0053] In this embodiment, Figure 6-8 A second type of magnetorheological damper is disclosed, whose working principle is similar to that of the first type. Adjustable damping characteristics are achieved by adjusting the swing gap between the swing assembly and the inner wall of the cylinder. The difference from the first structure is that the adjusting wrench 11 is fixed at the movable end in the second structure, thus simplifying the overall structure and improving the working stability of the magnetorheological damper while meeting usage requirements.

[0054] The second type of magnetorheological damper's swing gap adjustment working principle is as follows: Rotating the adjusting wrench 11 causes the adjusting nut 24 to rotate. Since the adjusting nut 24 and the piston rod 2 form a helical pair, the adjusting nut 24 moves axially and pushes the sliding sleeve 23 to move axially on the surface of the piston rod 2. Through the line contact formed between the inner conical surface of the sliding sleeve 24 and the outer conical surface of the magnetic guide tile 6, the magnetic attraction between the sector magnetic tile 7 and the cylinder 4 is overcome, and the gap between the swing assembly composed of the sector magnetic tile 7 and the magnetic guide tile 6 and the inner wall of the cylinder 4 is adjusted. This reduces the magnetic field strength generated at the gap of the magnetorheological composite material 8, and at the same time, the effective working area of ​​the magnetorheological composite material 8 and the cylinder 4 will decrease accordingly, realizing the variable damping characteristics of the damper. Furthermore, when the swing gap is too large, the magnetic attraction between the sector magnetic tile 7 and the cylinder 4 may not be able to adjust the swing assembly towards the direction of minimum swing gap. The return spring 22 is used to provide appropriate rebound force.

[0055] In this embodiment, a guide member 19 is further provided between the end cap and the piston rod 2. The guide member 19, together with the end cap, serves to guide and support the piston rod 2. Figure 1 and Figure 6 As shown, in the structure of the first magnetorheological damper, the guide 19 is installed on the left end cover 3 and together with the left end cover 3, it serves to guide and support the piston rod 2. In the structure of the second magnetorheological damper, the guide 19 is also installed on the left end cover 3. However, since the sliding sleeve 23 is sleeved on the piston rod 2 and can move linearly on the piston rod 2, the guide 19 supports and guides the sliding sleeve 23 while also supporting and guiding the piston rod 2.

[0056] A lifting lug is fixedly provided at the free end of the piston rod 2, and a lifting lug is fixedly provided on the outside of the end cap opposite to the piston rod 2 extending from the cylinder 4; combined with Figure 1 and Figure 6 As shown, the left lug 1 is fixed to the free end of the piston rod 2 and is connected to the free end of the piston rod 2 by a thread, while the right lug is fixed to the right end cover 12 by welding; by setting the left lug 1 and the right lug, the installation and use of the damper can be facilitated.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A passive magneto-rheological damper with adjustable swing gap, characterized in that: The system includes a cylinder body, a piston rod, and a piston assembly. The cylinder body includes a cylinder barrel with openings at both ends along the axial direction and end caps connected to the openings of the cylinder barrel. The piston assembly is slidably disposed within the cylinder barrel. The connecting end of the piston rod is connected to the piston assembly, and the free end of the piston rod extends axially through the end caps. The piston assembly includes a piston end cap disposed at the connecting end of the piston rod and a plurality of damping assemblies distributed circumferentially on the piston end caps. The damping assemblies are used to cooperate with the inner wall of the cylinder barrel to output damping force when the piston assembly slides. The connecting end of the damping assembly is hinged to the piston end caps, and the free end of the damping assembly can be driven to move away from the inner wall of the cylinder barrel. It also includes an adjustment component disposed inside the cylinder, the adjustment component being used to drive the free end of the damping component to swing about the hinge point in a direction away from the inner wall of the cylinder to adjust the size of the gap between the damping component and the inner wall of the cylinder; The damping component includes a magnet and a magnetorheological composite material. The magnet provides an excitation magnetic field to the magnetorheological composite material, which is located between the magnet and the inner wall of the cylinder and can generate a damping force for the relative sliding of the piston assembly under the action of the excitation magnetic field.

2. The oscillating gap adjustable passive magneto-rheological damper according to claim 1, wherein: The magnet includes a magnetic conductive tile and a sector-shaped magnetic tile. The connecting end of the magnetic conductive tile is hinged to the piston end cap via a pin. The sector-shaped magnetic tile is disposed on the outer surface of the magnetic conductive tile, and the magnetorheological composite material is disposed on the outer surface of the sector-shaped magnetic tile.

3. The oscillating gap adjustable passive magneto-rheological damper according to claim 2, wherein: The sector-shaped magnetic tiles are formed by radially outward magnetization to form outwardly magnetized sector-shaped magnetic tiles or by radially inward magnetization to form inwardly magnetized sector-shaped magnetic tiles. Multiple outwardly magnetized sector-shaped magnetic tiles and multiple inwardly magnetized sector-shaped magnetic tiles are arranged alternately to form an excitation magnetic field perpendicular to the magnetorheological composite material in the radial direction.

4. The oscillating gap adjustable passive magneto-rheological damper according to claim 3, wherein: The piston end cap is also provided with a fixed sleeve inside the damping assembly. The adjusting assembly includes a lead screw that can rotate around its own axis, an adjusting shaft for driving the lead screw to rotate, and a lead screw sleeve sleeved on the lead screw. One end of the lead screw is located inside the fixed sleeve and a support bearing is provided between it and the inner wall of the fixed sleeve, and a rotational fit is formed through the support bearing. The other end of the lead screw extends out of the fixed sleeve and has a threaded section on the outer side of the end. The lead screw sleeve is sleeved on the threaded section and threadedly connected to the lead screw. The lead screw is a hollow tubular rod with an internal spline. The connection end of the adjusting shaft to the lead screw is provided with an external spline. The connection end of the adjusting shaft to the lead screw is inserted into the lead screw and connected to the internal spline inside the lead screw through the external spline for transmission.

5. The oscillating gap adjustable passive magneto-rheological damper of claim 4, wherein: The free end of the magnetic conductive tile is provided with an outer conical top block with the working end facing inward. The outer surface of the lead screw sleeve is provided with a plurality of inner conical top cones along the circumferential direction for cooperating with the outer conical top block. The inner conical top cones and the outer conical top block are driven by line contact formed by the inner and outer conical surfaces. When the lead screw is driven to rotate around its own axis, the lead screw sleeve moves linearly on the threaded section of the lead screw, and the top cone of the inner conical hole makes line contact with the top block of the outer conical surface on the magnetic bearing, so as to drive the free end of the magnetic bearing to swing around the hinge point in a direction away from the inner wall of the cylinder.

6. The oscillating gap adjustable passive magneto-rheological damper of claim 4, wherein: The adjustment assembly also includes an adjustment wrench perpendicular to the adjustment shaft. The adjustment end of the adjustment wrench extends out of the cylinder through an adjustment hole. The adjustment hole is a strip-shaped hole opened circumferentially on the cylinder. By turning the adjustment wrench along the adjustment hole, the rotation of the adjustment shaft is driven, thereby rotating the lead screw.

7. The oscillating gap adjustable passive magneto-rheological damper of claim 3, wherein: The adjustment assembly includes a sliding sleeve fitted onto the piston rod and an adjustment wrench for driving the sliding sleeve to make linear displacement on the piston rod. The free end of the piston rod is provided with a threaded section. The adjustment wrench is perpendicular to the piston rod and is threadedly engaged with the threaded section. The free end of the magnetic conductive tile extends outward along the axial direction to form an outer conical surface. The sliding sleeve is recessed inward along the axial direction at the end that engages with the magnetic conductive tile to form an inner conical surface that is in line contact with the outer conical surface. By moving the adjusting wrench along the threaded section of the piston rod in a linear motion, the sliding sleeve is driven to move along the piston rod toward the interior of the cylinder, thereby making the inner conical surface of the sliding sleeve in line contact with the outer conical surface of the magnetic bearing, thus driving the free end of the magnetic bearing to swing away from the inner wall of the cylinder around the hinge point.

8. The oscillating gap adjustable passive magneto-rheological damper according to claim 7, characterized in that: A return spring is also provided between the magnetic conductive tile and the piston rod. The return spring is used to provide a rebound force for the magnetic conductive tile to reset.

9. The oscillating gap adjustable passive magneto-rheological damper of claim 3, wherein: A guide is also provided between the end cap and the piston rod, and the guide is used together with the end cap to guide and support the piston rod. A lifting lug is fixedly provided at the free end of the piston rod, and a lifting lug is fixedly provided on the outside of the end cap opposite to the piston rod extending out of the cylinder.

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