Variable stroke damping linear and rotary integrated magnetorheological damper

Abstract

The present invention provides a variable stroke damping linear and rotary integrated magnetorheological damper, comprising a cylinder body filled with magnetorheological fluid, a piston head assembly arranged in the cylinder body, and a piston rod axially extending through the cylinder body, the cylinder body comprising a cylinder barrel open at one end and an end cover connected to the cylinder barrel opening, the piston head assembly comprising a first piston head and a second piston head respectively connected to the piston rod, the first piston head being provided with a cavity inside and the cavity having different cross-sectional shapes at different axial positions of the first piston head, the second piston head being arranged in the cavity of the first piston head and being fixedly connected to the piston rod, and the second piston head driving the first piston head to move along the axial direction of the cylinder body when rotating synchronously with the piston rod to output damping forces of different intensities at different axial positions and different rotation angles; the present invention combines the working modes of linear and rotary magnetorheological dampers to meet the use under more complex working conditions such as multi-degree-of-freedom vibration reduction.

Description

Technical Field

[0001] The present invention relates to the field of magnetorheological vibration reduction technology, and in particular to a variable stroke damping linear and rotary integrated magnetorheological damper. Background Art

[0002] In terms of magnetorheological vibration reduction technology, the existing magnetorheological dampers mainly work in a single linear or rotary working mode, mainly using the excitation coil to generate a magnetic field, and then combining the magnetorheological material in the working gap to produce magnetorheological damping to achieve vibration reduction.

[0003] However, traditional rotary MR dampers cannot achieve different damping forces when the piston rotates to different angles during constant current operation. Furthermore, traditional continuous rotary MR dampers operate in shear mode, and the damping force output of the damper in shear mode is limited. Traditional linear MR dampers, on the other hand, mostly have a single damping path. Under constant current, they mostly achieve different damping forces for different strokes by changing the working gap. Furthermore, due to the limited damping force output and the inability to output different damping forces under constant current, after long-term operation, the MR damper is prone to ferromagnetic particle accumulation and blockage in the damping gap due to the small working gap, leading to damping channel failure and even damper jamming. Furthermore, in high-frequency vibration working environments, due to the compressibility and inertia of the liquid, traditional MR fluid dampers will experience high-frequency hardening, resulting in poor vibration reduction.

[0004] In view of the above-mentioned shortcomings of the existing magnetorheological dampers, and in combination with the current development needs in the field of magnetorheological vibration reduction technology, it is necessary to combine the working modes of linear magnetorheological dampers and rotary magnetorheological dampers to develop a variable stroke damping linear and rotary integrated magnetorheological damper, so as to meet the requirements of the magnetorheological damper to output damping forces of different intensities according to different axial stroke positions and different rotation angles in a high-frequency vibration working environment. Summary of the Invention

[0005] In view of this, the variable stroke damping linear rotation integrated magnetorheological damper provided by the present invention combines the working modes of the linear magnetorheological damper and the rotary magnetorheological damper, designs the inner wall of the second piston head into an irregular shape such as an ellipse, and changes the shape of the inner wall of the internal cavity of the first piston head, so that when the second piston head rotates to different angles and is in different axial positions in the first piston head, the magnetorheological damper can output different damping force values to meet the needs of more complex working conditions such as multi-degree-of-freedom vibration reduction.

[0006] The present invention can achieve the above problem through the following technical solutions:

[0007] A variable stroke damping linear rotation integrated magnetorheological damper, comprising a cylinder body filled with magnetorheological fluid, a piston head assembly arranged in the cylinder body, and a piston rod axially extending through the cylinder body, the cylinder body comprising a cylinder barrel open at one end and an end cover connected to the cylinder barrel opening, the piston head assembly comprising a first piston head and a second piston head respectively connected to the piston rod, a cavity being provided inside the first piston head and the cross-sectional shape of the cavity being different at different axial positions of the first piston head, the second piston head being arranged in the cavity of the first piston head and being fixedly connected to the piston rod, the second piston head rotating synchronously with the piston rod and driving the first piston head to move along the axial direction of the cylinder body to output damping forces of different intensities at different axial positions and different rotation angles.

[0008] Furthermore, an annular cavity is provided on the side wall of the cylinder along the axial direction of the cylinder, a magnetic sleeve is provided on the outer wall of the annular cavity, a damping adjustment component is provided in the annular cavity, and the damping adjustment component includes magnetorheological fluid and a ferromagnetic particle group, and the particle size of the ferromagnetic particles in the ferromagnetic particle group is different.

[0009] Furthermore, a sealing cover assembly for sealing the annular cavity is provided at the opening of the annular cavity, and the sealing cover assembly is connected and fixed to the cylinder barrel.

[0010] Furthermore, mounting grooves are radially provided on the outer circumferential surfaces of the first piston head and the second piston head, and excitation coils are installed in the mounting grooves.

[0011] Furthermore, a guide rod is provided in the cylinder body along the axial direction, one end of the guide rod is connected and fixed to the bottom of the cylinder barrel, and the other end is connected to the cylinder cover. The guide rod is used to guide the axial movement of the first piston head.

[0012] Furthermore, a threaded connection portion is provided on the piston rod, and the first piston head is connected to the piston rod via the threaded connection portion to form a screw structure.

[0013] Furthermore, the piston rod is provided with a sealing ring and a guide ring at the connection end with the cylinder body.

[0014] Furthermore, a through hole is axially provided at the bottom of the first piston head cavity, the gap between the first piston head and the inner wall of the cylinder forms a first damping channel for the flow of magnetorheological fluid, and the cavity of the first piston head and the through hole form a second damping channel for the flow of magnetorheological fluid.

[0015] Furthermore, the cross-sectional shape of the second piston head is elliptical and the center of the second piston head and the center of the piston rod are eccentrically arranged.

[0016] Furthermore, a plurality of oblique grooves are radially provided on the circumferential surface of the first piston head.

[0017] The beneficial effects of the present invention are:

[0018] (1) The integrated magnetorheological damper combines the working modes of a linear magnetorheological damper and a rotary magnetorheological damper. By designing the inner wall of the second piston head into an irregular shape such as an ellipse and changing the shape of the inner wall of the internal cavity of the first piston head, the damper can output different damping force values when the second piston head is rotated to different angles and is at different axial positions in the first piston head.

[0019] (2) The integrated magnetorheological damper is designed to have an eccentric structure for the connection between the second piston head and the piston rod, so that when the second piston head rotates, there is a very small gap between one end and the inner wall of the first piston head cavity, which is sufficient for the second piston head to push the magnetorheological fluid to flow, thereby realizing a composite working mode in which shear mode, flow (valve) mode and extrusion mode coexist, greatly improving the damping force output of the magnetorheological damper;

[0020] (3) The integrated magnetorheological damper forms a screw structure between the first piston head and the piston rod by processing a threaded line for connecting the first piston on the piston rod. When the second piston head rotates with the piston rod, the first piston moves linearly under the action of the thread. This makes the magnetorheological damper have the functions of both a rotary damper and a linear damper, and can be used in more complex working conditions such as multi-degree-of-freedom vibration reduction.

[0021] (4) The integrated magnetorheological damper is provided with multiple damping channels that work simultaneously, thereby increasing the output of the shock absorber. In addition, multiple oblique grooves are designed on the outer circumferential surface of the first piston head, so that the magnetorheological fluid can flow more fully in the oblique grooves, thereby avoiding the accumulation of ferromagnetic particles in the working gap, which may lead to the failure of the working gap of the shock absorber and even the phenomenon of the shock absorber being stuck.

[0022] (5) When the integrated magnetorheological damper is working, by filling the annular cavity of the cylinder with ferromagnetic particles of different particle sizes, the ferromagnetic particles of different particle sizes will collide with the ferromagnetic particle chains on the magnetic flux path, thereby destroying the formation of the ferromagnetic particle chains on the magnetic path and causing the ferromagnetic particle chains on the magnetic path to continuously reorganize, thereby dissipating more energy, making the magnetorheological damper have good performance under high-frequency vibration;

[0023] (6) When the integrated magnetorheological damper is installed vertically and used as a linear damper, the ferromagnetic particles of different sizes in the annular cavity of the cylinder will flow to one end under the action of gravity. The accumulated ferromagnetic particles will affect the magnetic induction intensity passing through the working gap, thereby achieving that under constant current, the linear magnetorheological damper can output different damping forces at different strokes. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] Figure 1 2 is a cross-sectional view of the overall structure of the integrated magnetorheological damper of the present invention;

[0026] Figure 2 for Figure 1 The cross-sectional view of the AA section;

[0027] Figure 3 for Figure 1 Cross-sectional view of BB section;

[0028] Figure 4 Schematic diagram of the magnetic flux path around the first piston and the second piston in the present invention;

[0029] Figure 5 This is a cross-sectional view of the overall structure of the integrated magnetorheological damper of the present invention when it is installed vertically;

[0030] The figures are marked as follows: 1-piston rod; 2, 10, 14, 15, 16, 28-O-ring; 3-sealing cover; 4-cylinder; 5-magnetic sleeve; 6-oblique groove; 7-ferromagnetic particle group; 8-annular cavity; 9-guide rod; 11-end cover; 12-hexagon socket bolt; 13-guide ring; 17-cavity; 18-first piston head; 19, 26-shaft retaining ring; 20, 21-excitation coil; 22-mounting key; 23-second piston head; 24-through hole; 25-threaded connection; 27-wire groove; 29-magnetic flux path. DETAILED DESCRIPTION

[0031] As shown in the figure, the variable stroke damping linear rotation integrated magnetorheological damper provided by the present invention includes a cylinder body filled with magnetorheological fluid, a piston head assembly arranged in the cylinder body, and a piston rod 1 axially passing through the cylinder body. The cylinder body includes a cylinder barrel 4 with an opening at one end and an end cover 11 connected to the cylinder barrel opening. The piston head assembly includes a first piston head 18 and a second piston head 23 respectively connected to the piston rod 1. A cavity 17 is provided inside the first piston head 18, and the cross-sectional shape of the cavity 17 at different axial positions of the first piston head 18 is different. The second piston head 23 is arranged in the cavity 17 of the first piston head and is connected and fixed to the piston rod 1. The second piston head 23 rotates synchronously with the piston rod 1 and drives the first piston head 18 to move along the axial direction of the cylinder body to output damping forces of different strengths at different axial positions and different rotation angles; wherein the cylinder barrel 4 is made of weak magnetic conductive material and is filled with magnetorheological fluid, and the open end of the cylinder barrel 4 is provided with an end cover 11, which is screwed and fixed to the cylinder barrel 4 by threads, and the O-rings 10 and 14 play the role of sealing and preventing liquid leakage; and the first The second piston head 23 is surrounded by an excitation coil for forming an excitation magnetic field and is fixed to the piston rod 1 through a mounting key 22 and a shaft retaining ring 19, and can rotate with the piston rod 1; the first piston head 18 is connected to the piston rod 1 and is provided with a cavity 17 inside, the second piston head 23 is arranged in the cavity 17 and forms a rotary magnetorheological damper structure with the first piston head 18, wherein the inner wall cross-sectional shape of the cavity 17 is different at different axial positions (the specific shape is designed according to actual needs), forming a spatial topological cross-sectional shape, so that when the second piston head 18 is connected to the piston rod 1, a cavity 17 is provided inside the second piston head 23. When the plug head 23 is in different axial positions inside the first piston head 18 and rotates at different angles, the gap between the second piston head 23 and the first piston head 18 also changes accordingly, so that the damper can output different damping forces when the second piston head 23 rotates at different angles; the integrated magnetorheological damper has both the functions of a rotary damper and a linear damper, thereby obtaining a variable stroke damping linear rotary integrated magnetorheological damper, which achieves greater damping force output to meet the needs of more complex working conditions such as multi-degree-of-freedom vibration reduction.

[0032] In this embodiment, the side wall of the cylinder 4 is provided with an annular cavity 8 along the axial direction of the cylinder, and a magnetic conductive sleeve 5 is provided on the outer wall of the annular cavity 8. A damping adjustment component is provided in the annular cavity 8, and the damping adjustment component includes a magnetorheological fluid and a ferromagnetic particle group 7. The ferromagnetic particles in the ferromagnetic particle group 7 have different particle sizes; Figure 1As shown, the magnetic sleeve 5 is made of a strong magnetic material and is mainly used to cooperate with the first piston head 18 to form a magnetic flow path 29. The magnetic sleeve 5 is screwed to the cylinder 4 through a thread, and the O-ring 2 plays a sealing role; the damping adjustment component arranged in the annular cavity 8 is mainly composed of a magnetorheological fluid and a ferromagnetic particle group 7 composed of ferromagnetic particles of different particle sizes, wherein the ferromagnetic particle group does not completely fill the annular cavity 8; when the damper is working, the collision and friction between particles of different particle sizes will consume the vibration energy of the system. At the same time, since the guide rod 9 is a non-magnetic material, the cylinder 4 is a weak magnetic material, and the sleeve 5 is a strong magnetic material, when the excitation coil 20 is energized, the generated magnetic flux lines will pass through the cylinder 4 and the annular cavity 8, and the first piston head 18 and the magnetic sleeve 5 form a closed magnetic flux loop. Combined Figure 4 As shown, when the magnetorheological damper starts working and the excitation coil 20 is energized, the ferromagnetic particles in the annular cavity 8 will form a chain structure on the magnetic flux path, and the friction between the ferromagnetic particles will also increase. The ferromagnetic particles of different particle sizes in the annular cavity 8 that are not arranged into a chain will collide with the chain-like ferromagnetic particles on the magnetic flux path, which will destroy the formation of the ferromagnetic particle chain on the magnetic path. The ferromagnetic particle chain on the magnetic path will continue to reorganize, resulting in more energy dissipation, so that the integrated magnetorheological damper has good performance under high-frequency vibration.

[0033] In this embodiment, a sealing cover assembly for sealing the annular cavity 8 is provided at the opening of the annular cavity, and the sealing cover assembly is connected and fixed to the cylinder 4; Figure 1 As shown, the sealing cover assembly includes a sealing cover 3, an O-ring 15 and an O-ring 16 arranged between the sealing cover and the sleeve, wherein the sealing cover 3 is an annular cover, and a threaded portion is provided on the inner side thereof, which is connected and fastened to the cylinder 4 by a threaded manner to prevent leakage of the magnetorheological fluid in the annular cavity 8.

[0034] In this embodiment, the outer circumferential surfaces of the first piston head 18 and the second piston head 23 are radially provided with mounting grooves, in which excitation coils are installed; Figure 1 As shown, an excitation coil 20 is arranged around the mounting groove of the first piston head 18, and the energized end of the excitation coil 20 extends out of the damper through the wire groove 27 and is connected to the external power supply, wherein the wire groove 27 needs to be sealed with a sealing material to prevent leakage of the magnetorheological fluid, and an excitation coil 21 is installed in the mounting groove of the second piston head 23, and the excitation coil 21 is connected to the external power supply through the wire hole opened in the piston rod 1; by arranging the excitation coils on the first piston head 18 and the second piston head 23, an excitation magnetic field is formed when they are energized to act on the magnetorheological fluid, thereby finally generating a damping force.

[0035] In this embodiment, a guide rod 9 is further provided in the cylinder body along the axial direction. One end of the guide rod 9 is connected and fixed to the bottom of the cylinder barrel 4, and the other end is connected to the end cover 11. The guide rod 9 is used to guide the axial movement of the first piston head 18; Figure 1 As shown, the guide rod 9 is a fixed rod made of non-magnetic material and connected to the cylinder 4, one end of which is connected to the bottom of the cylinder 4, and the outer end is pressed and fixed to the end cover 11 by the hexagon socket bolt 12, wherein the guide rod 9 is mainly used to limit the circumferential rotation of the first piston head 18 and guide the axial movement of the first piston head 18, so that the first piston head 18 can only move axially along the piston rod 1.

[0036] In this embodiment, a threaded connection portion 25 is provided on the piston rod 1, and the first piston head 18 is connected to the piston rod 1 through the threaded connection portion 25 to form a screw structure; by processing the threaded connection portion 25 on the piston rod 1 and connecting the threaded connection portion 25 with the first piston head 18 to form a screw structure, when the second piston head 23 rotates along with the piston rod 1 under the action of the mounting key 22, the first piston head 18 moves linearly along the guide rod 9 under the action of the threaded connection portion 25. When the excitation coil 20 is energized, the magnetorheological fluid between the first piston head 18 and the cylinder 4 acts to generate a damping force, so that the first piston head 18 acts as a linear damper, and the second piston head 23 acts as a rotary damper, so that the magnetorheological damper has the effect of a rotary damper as well as the effect of a linear damper, and integrates the functions of linear and rotary dampers to achieve greater damping force output.

[0037] In this embodiment, the piston rod 1 is provided with a sealing ring and a guide ring 13 at the connection end with the cylinder body; Figure 1 As shown, an O-ring 14 and a guide ring 13 are respectively provided at the connection ends of the piston rod 1 with the cylinder 4 and the end cover 11. The O-ring 14 is used to seal and prevent liquid leakage, and the guide ring 13 is used to guide the linear motion of the piston rod.

[0038] In this embodiment, a through hole 24 is axially provided at the bottom of the first piston head cavity, and the gap between the first piston head 18 and the inner wall of the cylinder forms a first damping channel for the flow of magnetorheological fluid, and the cavity of the first piston head and the through hole form a second damping channel for the flow of magnetorheological fluid; when the piston rod 1 only moves in a straight line, the first piston head 18 and the second piston head 23 are driven to move in a straight line, and at this time the integrated magnetorheological damper only acts as a linear damper; in this state, the magnetorheological fluid in the cylinder 4 can, on the one hand, flow through the gap between the first piston head 18 and the cylinder 4, and since the first piston head 18 is a hollow structure, the magnetorheological fluid can also flow through the gap between the first piston head 18 and the second piston head 23, which is equivalent to adding a damping channel, realizing that multiple damping channels work at the same time, thereby achieving the purpose of increasing the damping force output.

[0039] In this embodiment, the cross-sectional shape of the second piston head 23 is elliptical and the center of the second piston head 23 is eccentric to the center of the piston rod 1; Figure 2 and Figure 3 As shown, the cross-section of the second piston head 23 is elliptical, and of course it can also be designed into other irregular shapes according to actual needs, and is connected to the piston rod 1 in an eccentric structure, mainly to ensure that the second piston head 23 can continue to squeeze the magnetorheological fluid when rotating; therefore, when the second piston head 23 rotates, there will be a very small gap between one end of the second piston head 23 and the inner wall of the cavity of the first piston head 18, which is enough to enable the second piston head 23 to push and squeeze the magnetorheological fluid between it and the first piston head 18, thereby realizing a composite working mode in which shear mode, flow (valve) mode and extrusion mode coexist, greatly improving the damping force output of the integrated magnetorheological damper.

[0040] In this embodiment, a plurality of oblique grooves 6 are radially provided on the outer circumferential surface of the first piston head 18; since the working gap between the first piston head 18 and the cylinder 4 is relatively narrow, when the damper is in operation for a long time, ferromagnetic particles in the magnetorheological fluid are likely to accumulate and clog in the working gap, hindering the flow of the magnetorheological fluid and affecting the use of the magnetorheological damper; by designing a plurality of oblique grooves 6 on the surface of the first piston head 18, the magnetorheological fluid can flow fully in the oblique grooves 6, avoiding the occurrence of accumulation and blockage of ferromagnetic particles in the working gap, and ensuring the normal operation of the integrated magnetorheological damper.

[0041] In this embodiment, combined with Figure 5As shown, when the integrated magnetorheological damper is installed vertically and used as a linear damper, ferromagnetic particles of different particle sizes in the annular cavity 8 will flow to one side of the damper under the action of gravity. Due to the different particle sizes, more small-size and large-size particles will accumulate at the bottom. When the magnetic flux lines generated by the first piston head 18 pass through the annular cavity 8, more small-size particles and large-size particles will accumulate at the bottom with a small distance between each other, and there are only a small number of ferromagnetic particles at the top with a large distance between each other. The magnetic induction intensity is large where the accumulation number is large, which causes the damper to output different damping forces when the first piston head 18 is in different strokes.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention 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 invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A variable stroke damping linear and rotary integrated magnetorheological damper, characterized by: The invention comprises a cylinder body filled with magnetorheological fluid, a piston head assembly arranged in the cylinder body, and a piston rod axially extending through the cylinder body, wherein the cylinder body comprises a cylinder barrel with an opening at one end and an end cover connected to the cylinder barrel opening, and the piston head assembly comprises a first piston head and a second piston head respectively connected to the piston rod, wherein a cavity is provided inside the first piston head, and the cross-sectional shape of the cavity at different axial positions of the first piston head is different, and the second piston head is arranged in the cavity of the first piston head and is fixedly connected to the piston rod, and the second piston head rotates synchronously with the piston rod and drives the first piston head to move along the axial direction of the cylinder body to output damping forces of different intensities at different axial positions and different rotation angles; An annular cavity is provided on the side wall of the cylinder along the axial direction of the cylinder, a magnetic sleeve is provided on the outer wall of the annular cavity, a damping adjustment component is provided in the annular cavity, and the damping adjustment component includes magnetorheological fluid and a ferromagnetic particle group, and the particle size of the ferromagnetic particles in the ferromagnetic particle group is different; the first piston head and the second piston head are provided with mounting grooves in the radial direction on the outer circumferential surface, and an excitation coil is installed in the mounting groove; the cross-sectional shape of the second piston head is elliptical and the center of the second piston head is eccentrically arranged with the center of the piston rod.

2. The variable stroke damping linear and rotary integrated magnetorheological damper according to claim 1, characterized in that: A sealing cover assembly for sealing the annular cavity is provided at the opening of the annular cavity, and the sealing cover assembly is fixedly connected to the cylinder barrel.

3. The variable stroke damping linear and rotary integrated magnetorheological damper according to claim 1, characterized in that: A guide rod is further provided in the cylinder body along the axial direction, one end of the guide rod is connected and fixed to the bottom of the cylinder barrel, and the other end is connected to the end cover. The guide rod is used to guide the axial movement of the first piston head.

4. The variable stroke damping linear and rotary integrated magnetorheological damper according to claim 1, characterized in that: The piston rod is provided with a threaded connection portion, and the first piston head is connected to the piston rod through the threaded connection portion to form a screw rod structure.

5. The variable stroke damping linear and rotary integrated magnetorheological damper according to claim 4, characterized in that: The piston rod is respectively provided with a sealing ring and a guide ring at the connection end with the cylinder body.

6. The variable stroke damping linear and rotary integrated magnetorheological damper according to claim 1, characterized in that: A through hole is axially provided at the bottom of the first piston head cavity; the gap between the first piston head and the inner wall of the cylinder forms a first damping channel for the flow of magnetorheological fluid; the cavity of the first piston head and the through hole form a second damping channel for the flow of magnetorheological fluid.

7. The variable stroke damping linear and rotary integrated magnetorheological damper according to claim 1, characterized in that: A plurality of oblique grooves are radially formed on the circumferential surface of the first piston head.

Images