Passive magneto-rheological damper with travel sensitive damping

Abstract

The application discloses a passive magneto-rheological damper with stroke-sensitive damping, and relates to the field of damping and vibration reduction, which comprises a cylinder, a variable-gap working cylinder capable of moving axially on the inner wall of the cylinder, a piston assembly arranged in the variable-gap working cylinder, and a cylinder cover arranged at the end of the cylinder for plugging the cylinder, the cylinder is filled with magneto-rheological fluid, the inner wall of the variable-gap working cylinder is provided with a profile surface and is symmetric along the axial center, the piston assembly comprises a piston head and a piston rod, one end of the piston rod penetrates through the cylinder cover, the piston head comprises a permanent magnet arranged at the end of the piston rod for generating a magnetic field, and an adjusting assembly is arranged on the cylinder for adjusting the movement of the variable-gap working cylinder in the cylinder; the electric control system is avoided, stable and reliable damping characteristics can be provided in a specific environment, and the damping force of the damper can provide different damping force values according to the vibration amplitude.

Description

Technical Field

[0001] The present invention relates to the field of damping and vibration reduction, and in particular to a passive magnetorheological damper with stroke-sensitive damping. Background Art

[0002] Mechanical systems in certain situations are subject to widely varying vibration excitations at varying vibration amplitudes, requiring the damping force to vary continuously with travel. Failure to effectively address these vibrations can lead to reduced efficiency in the mechanical system. Current magnetorheological dampers primarily adapt the damping force by monitoring the system's real-time status and adjusting the external input current, thereby improving the system's vibration reduction performance. However, in specialized environments where reliable performance is crucial, the introduction of excitation coils and sensor systems increases the damper's failure rate and operational costs. These design requirements pose a significant threat to the development of magnetorheological technology and will restrict its development and application in specialized fields. Summary of the Invention

[0003] In view of this, an object of the present invention is to provide a passive magnetorheological damper with stroke-sensitive damping, in which the effective damping gap thickness varies with the stroke, and different damping forces can be passively provided according to the change of the stroke.

[0004] The present invention provides a passive magnetorheological damper with stroke-sensitive damping, which adopts the following technical solutions:

[0005] A passive magnetorheological damper with stroke-sensitive damping comprises a cylinder, a variable-gap working cylinder that can move axially on the inner wall of the cylinder, a piston assembly arranged in the variable-gap working cylinder, and a cylinder cover arranged at the end of the cylinder for sealing the cylinder. The cylinder is filled with magnetorheological fluid, the inner wall of the variable-gap working cylinder is arranged in a contour surface and is symmetrical along the axial center. The piston assembly comprises a piston head and a piston rod, one end of the piston rod passes through the cylinder cover, the piston head comprises a permanent magnet arranged at the end of the piston rod for generating a magnetic field, and the cylinder is provided with an adjustment assembly for adjusting the movement of the variable-gap working cylinder in the cylinder.

[0006] Furthermore, the adjustment assembly includes an adjustment sleeve threaded on the cylinder and a thrust ring slidably arranged in the cylinder. The end of the adjustment variable gap working cylinder abuts against the thrust ring. Rotating the adjustment sleeve can drive the thrust ring to move the adjustment variable gap working cylinder in the cylinder.

[0007] Furthermore, a return spring is provided in the cylinder, and two ends of the return spring respectively contact the inner wall of the cylinder and the end of the variable gap adjusting working cylinder away from the thrust ring.

[0008] Furthermore, the outer wall of the thrust ring is threadedly connected with an adjusting column, the inner wall of the adjusting sleeve is provided with an annular groove for accommodating the adjusting column, and the side wall of the cylinder is provided with a through groove for the adjusting column to move.

[0009] Furthermore, a sleeve is provided in the cylinder at one end away from the cylinder cover, and the end of the return spring away from the variable gap adjustment working cylinder abuts against the sleeve. A floating piston is provided in the sleeve for maintaining internal pressure balance.

[0010] Furthermore, a boss is provided on the inner wall of the end portion of the sleeve for preventing the floating piston from escaping from the sleeve.

[0011] Furthermore, the piston head also includes a left back iron and a right back iron arranged on both sides of the permanent magnet.

[0012] Furthermore, the piston rod is provided with a shaft shoulder for limiting the right back iron, and the left back iron is threadedly sleeved on the end of the piston rod.

[0013] Furthermore, the left back iron, the right back iron and the variable gap working cylinder are all made of magnetic conductive materials.

[0014] Furthermore, both the end of the cylinder and the end of the piston rod extending out of the cylinder are provided with lifting ears, and the piston rod is threadedly mounted in cooperation with the lifting ears.

[0015] In summary, the present invention has at least one of the following beneficial effects:

[0016] 1. It can avoid the use of electronic control systems and provide stable and reliable damping characteristics in specific environments. The damping force of the damper can provide different damping force values ​​according to the vibration amplitude;

[0017] 2. The damping characteristics of the damper are mainly determined by the inner profile of the variable gap working cylinder, so a specific working profile can be designed according to actual damping requirements;

[0018] 3. When the vibration reduction system changes relative to the initial installation position of the damper, if the piston head needs to remain in the equilibrium position, the axial position of the variable clearance cylinder can be adjusted to keep it in the equilibrium position. Similarly, the damping force characteristics can be adjusted in this way. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the structure of an embodiment of the present invention;

[0020] Figure 2 This is a schematic structural diagram of a cylinder according to an embodiment of the present invention;

[0021] Figure 3 Schematic diagram of the structure of the thrust ring according to an embodiment of the present invention.

[0022] Description of reference numerals:

[0023] 1. Cylinder barrel; 11. Return spring; 12. Through groove; 13. Sleeve; 14. Floating piston; 15. Boss; 2. Variable clearance working cylinder; 3. Piston assembly; 31. Piston head; 311. Permanent magnet; 312. Left back iron; 313. Right back iron; 32. Piston rod; 4. Cylinder head; 5. Adjustment assembly; 51. Adjustment sleeve; 511. Groove; 52. Thrust ring; 53. Adjustment column; 6. Lifting ear. DETAILED DESCRIPTION

[0024] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0025] The following is combined with Figure 1-3 The present invention is described in further detail.

[0026] The embodiment of the present invention discloses a passive magnetorheological damper with stroke-sensitive damping. Figure 1-Figure 3 The passive magnetorheological damper with stroke-sensitive damping includes a cylinder 1, a variable-gap working cylinder 2 that can move axially on the inner wall of the cylinder 1, a piston assembly 3 arranged in the variable-gap working cylinder 2, and a cylinder cover 4 arranged at the end of the cylinder 1 for sealing the cylinder 1. The end cover 4 is installed with the cylinder 1 by means of threads, and other installation methods can also be used. The cylinder 1 is filled with magnetorheological fluid, the inner wall of the variable-gap working cylinder 2 is configured as a contour surface and the inner wall is symmetrical along the axial center. A transition fit is adopted between the variable-gap working cylinder 2 and the cylinder 1 to ensure that the sealing is improved under the premise of smooth movement. The piston assembly 3 includes a piston head 31 and a piston rod 32. One end of the piston rod 31 passes through the cylinder cover 4. The piston head 31 includes a piston rod 31 provided at the end of the piston rod 31 for generating a magnetic field. The permanent magnet 311 is provided on the cylinder 1, and an adjustment component 5 is provided for adjusting the movement of the variable gap working cylinder 2 in the cylinder 1. At the same time, the cylinder 1 needs to be sealed, and each connection needs to be sealed; the magnetorheological fluid between the piston head 31 and the variable gap working cylinder 2 produces a magnetorheological effect, thereby generating a damping force for the piston movement. When the axial length of the damper installation changes, the piston head 31 is no longer in a balanced position. The variable gap working cylinder 2 is moved in the cylinder 1 through the adjustment component 5, thereby ensuring that the piston head 31 can still be in a balanced position, ensuring that the damper can always be in a balanced position under different preload conditions, and at the same time, the thickness of the gap between the piston head 31 and the variable gap working cylinder 2 also changes accordingly, so that the damper can generate a damping force associated with the stroke.

[0027] In this embodiment, the inner wall of the variable-gap working cylinder 2 is designed according to the damping force required in actual work, and can provide different damping characteristics.

[0028] In this embodiment, the adjusting assembly 5 includes an adjusting sleeve 51 threadedly mounted on the cylinder 1 and a thrust ring 52 slidably arranged in the cylinder 1. A sealing ring may be provided at the annular groove of the inner ring of the adjusting sleeve 51 on the side close to the cylinder head 4 to improve the sealing of the entire chamber; the end of the adjusting variable gap working cylinder 2 abuts against the thrust ring 52, and rotating the adjusting sleeve 51 can drive the thrust ring 52 to move the adjusting variable gap working cylinder 2 in the cylinder 1. When the axial length of the damper installation changes, the piston head 31 is no longer in the equilibrium position. The adjusting sleeve 51 is rotated to push the thrust ring 52 to cause the variable gap working cylinder 2 to undergo the same displacement, thereby ensuring that the piston head 31 can still be in the equilibrium position. The vibration reduction system requires the damper to provide different damping characteristics. It only needs to rotate the adjusting sleeve 51 to make the variable gap working cylinder 2 in different positions according to the damping requirements, thereby providing different damping characteristics.

[0029] In this embodiment, a return spring 11 is provided in the cylinder 1, and the two ends of the return spring 11 respectively abut against the inner wall of the cylinder 1 and the end of the variable gap working cylinder 2 that is adjusted to be away from the thrust ring 52. When the variable gap working cylinder 2 moves into the cylinder 1, the variable gap working cylinder 2 will compress the return spring 11. When the variable gap working cylinder 2 needs to move outward from the cylinder 1, the adjusting sleeve 51 causes the thrust ring 52 to move outward from the cylinder 1, and the thrust ring 52 leaves the end of the variable gap working cylinder 2. The variable gap working cylinder 2 also moves outward under the action of the return spring 11 until it abuts against the thrust ring 52.

[0030] In this embodiment, the outer wall of the thrust ring 52 is threadedly connected with an adjusting column 53, and the inner wall of the adjusting sleeve 51 is provided with an annular groove 511 for accommodating the adjusting column 53. The side wall of the cylinder 1 is provided with a through groove 12 for the adjusting column 53 to move. When the adjusting sleeve 51 is rotated, the adjusting column 53 moves relatively in the groove 511, and at the same time, the adjusting sleeve 51 moves through the adjusting column 53 to push the thrust ring 52 to move. During the movement of the thrust ring 52, the adjusting column 53 moves in the through groove 12 of the cylinder 1. At the same time, the number of adjusting columns 53 can be multiple, and at this time the number of through grooves 12 needs to correspond to the number of adjusting columns 53.

[0031] In this embodiment, a sleeve 13 is provided at the end of the cylinder 1 away from the cylinder head 4, and the end of the return spring 11 away from the variable gap adjustment working cylinder 2 abuts against the sleeve 13. A floating piston 14 is provided in the sleeve 13 for maintaining internal pressure balance.

[0032] In this embodiment, a boss 15 is provided on the inner wall of the end portion of the sleeve 13 for preventing the floating piston 14 from separating from the sleeve 13 .

[0033] In this embodiment, the piston head 31 also includes a left back iron 312 and a right back iron 313 arranged on both sides of the permanent magnet 311. The left back iron 312, the right back iron 313 and the permanent magnet 311 are gap-fitted, and the left back iron 312 and the right back iron 313 can protect the permanent magnet 311.

[0034] In this embodiment, a shoulder for limiting the right back iron 313 is provided on the piston rod 32 , and the left back iron 312 is threadedly sleeved on the end of the piston rod 32 .

[0035] In this embodiment, the left back iron 312 , the right back iron 313 and the variable gap working cylinder 2 are all made of magnetic conductive materials, which can better guide the magnetic field generated by the permanent magnet 311 to pass vertically through the damping gap.

[0036] In this embodiment, both the end of the cylinder 1 and the end of the piston rod 32 extending out of the cylinder 1 are provided with a lifting lug 6 , and the piston rod 32 is threadedly mounted in cooperation with the lifting lug 6 .

[0037] 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 passive magnetorheological damper with stroke-sensitive damping, characterized in that: The invention comprises a cylinder (1), a variable gap working cylinder (2) arranged inside the cylinder (1) and axially movable on the inner wall of the cylinder, a piston assembly (3) arranged in the variable gap working cylinder (2), and a cylinder cover (4) arranged at the end of the cylinder (1) for sealing the cylinder (1). The cylinder (1) is a closed structure with one end open. The cylinder (1) is filled with magnetorheological fluid. The inner wall of the variable gap working cylinder (2) is arranged in a contoured surface and is symmetrical along the axial center. The piston assembly (3) comprises a piston head (31) and a piston rod ( 32), one end of the piston rod (31) passes through the cylinder cover (4), the piston head (31) includes a permanent magnet (311) provided at the end of the piston rod (31) for generating a magnetic field, and the cylinder barrel (1) is provided with an adjustment component (5) for adjusting the movement of the variable gap working cylinder (2) in the cylinder barrel (1); when the variable gap working cylinder (2) moves in the cylinder barrel (1), the thickness of the gap between the piston head (31) and the inner wall of the variable gap working cylinder (2) also changes accordingly, and the damper can generate a damping force associated with the stroke; The adjusting assembly (5) comprises an adjusting sleeve (51) threadedly sleeved on the cylinder (1) and a thrust ring (52) slidably arranged in the cylinder (1); the end of the adjusting variable gap working cylinder (2) abuts against the thrust ring (52); the adjusting sleeve (51) is rotated to drive the thrust ring (52) to move the adjusting variable gap working cylinder (2) in the cylinder (1); A return spring (11) is provided in the cylinder (1), and two ends of the return spring (11) respectively contact the inner wall of the cylinder (1) and one end of the variable-gap adjusting working cylinder (2) away from the thrust ring (52); The outer wall of the thrust ring (52) is threadedly connected to an adjusting column (53), the inner wall of the adjusting sleeve (51) is provided with an annular groove (511) for accommodating the adjusting column (53), and the side wall of the cylinder (1) is provided with a through groove (12) for the adjusting column (53) to move.

2. The passive magnetorheological damper with stroke-sensitive damping according to claim 1, characterized in that: A sleeve (13) is provided at one end of the cylinder barrel (1) away from the cylinder cover (4), and an end of the return spring (11) away from the variable clearance adjustment working cylinder (2) abuts against the sleeve (13). A floating piston (14) is provided in the sleeve (13) for maintaining internal pressure balance.

3. The passive magnetorheological damper with stroke-sensitive damping according to claim 2, characterized in that: The inner wall of the end of the sleeve (13) is provided with a boss (15) for preventing the floating piston (14) from separating from the sleeve (13).

4. The passive magnetorheological damper with stroke-sensitive damping according to claim 1, characterized in that: The piston head (31) further comprises a left back iron (312) and a right back iron (313) arranged on both sides of the permanent magnet (311).

5. The passive magnetorheological damper with stroke-sensitive damping according to claim 4, characterized in that: The piston rod (32) is provided with a shaft shoulder for limiting the right back iron (313), and the left back iron (312) is threadedly sleeved on the end of the piston rod (32).

6. The passive magnetorheological damper with stroke-sensitive damping according to claim 5, characterized in that: The left back iron (312), the right back iron (313) and the variable gap working cylinder (2) are all made of magnetic conductive materials.

7. The passive magnetorheological damper with stroke-sensitive damping according to claim 1, characterized in that: The end of the cylinder (1) and the end of the piston rod (32) extending out of the cylinder (1) are both provided with a lifting lug (6), and the piston rod (32) is threadedly mounted in cooperation with the lifting lug (6).

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