Passive magnetorheological damper with stroke sensitive damping

Abstract

The invention discloses a passive magnetorheological damper with stroke sensitive damping, which relates to the field of damping vibration attenuation, and comprises a cylinder barrel, a variable clearance working barrel capable of axially moving on the inner wall of the cylinder barrel, a piston assembly arranged in the variable clearance working barrel, and a cylinder cover arranged at the end part of the cylinder barrel and used for blocking the cylinder barrel, the inner wall of the variable-gap working barrel is arranged in a contour surface mode and is in central symmetry in the axial direction, the piston assembly comprises a piston head and a piston rod, one end of the piston rod penetrates through the cylinder cover, and the piston head comprises a permanent magnet which is arranged at the end of the piston rod and used for generating a magnetic field. The cylinder barrel is provided with an adjusting assembly used for adjusting the variable-gap working barrel to move in the cylinder barrel. An electric control system can be 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 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] For mechanical systems in some specific occasions, the system will be subjected to greatly different vibration excitations under different vibration amplitudes, which requires the damping force to change continuously with the stroke. If this type of vibration problem is not effectively solved, the working efficiency of the mechanical system will decrease. The current magnetorheological damper mainly adjusts the external input current by monitoring the real-time status of the system to achieve the adaptation of the damping force and improve the vibration reduction performance of the system. However, for some special environments that pursue reliable performance, the introduction of excitation coils and sensor systems will increase the failure rate and operation and maintenance costs of the damper. These design requirements are fatal to the development of magnetorheological technology and will restrict the development and application of magnetorheological technology in special 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 thickness of the effective damping gap varies with the change of 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 which 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, wherein the cylinder is filled with magnetorheological fluid, the inner wall of the variable-gap working cylinder is arranged in a contour surface and the inner wall 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 an adjusting assembly is arranged on the cylinder for adjusting the variable-gap working cylinder to move 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, and 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 arranged in the cylinder, and two ends of the return spring respectively abut against the inner wall of the cylinder and one end of the variable clearance adjusting working cylinder away from the thrust ring.

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

[0009] Furthermore, a sleeve is arranged at one end of the cylinder away from the cylinder head, one end of the return spring away from the variable clearance adjusting working cylinder abuts against the sleeve, and a floating piston for maintaining internal pressure balance is arranged in the sleeve.

[0010] Furthermore, a boss is provided on the inner wall of the end 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, a shoulder for limiting the right back iron is provided on the piston rod, 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, the end of the cylinder barrel and the end of the piston rod extending out of the cylinder barrel are both provided with lifting ears, and the piston rod is installed in threaded cooperation with the lifting ears.

[0015] In summary, the present invention comprises 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 contour of the variable gap working cylinder, so a specific working contour can be designed according to the 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 a balanced position, the axial position of the variable clearance cylinder can be adjusted to keep it in a balanced position. Similarly, the damping force characteristics can be adjusted in this way. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;

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

[0021] Figure 3 It is a schematic structural diagram of a 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, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways 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, and the inner wall of the variable-gap working cylinder 2 is arranged in 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 improve the sealing performance while ensuring its 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, and the piston head 31 includes a piston rod 31 disposed at the end of the piston rod 31 for generating a magnetic field. The permanent magnet 311 is provided on the cylinder 1 for adjusting the variable gap working cylinder 2 to move to the adjustment component 5 in the cylinder 1. At the same time, the cylinder 1 needs to ensure sealing, 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 sleeved 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 a balanced position. The adjusting sleeve 51 is rotated to push the thrust ring 52 to cause the variable gap working cylinder 2 to have the same displacement, thereby ensuring that the piston head 31 can still be in a balanced 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 one end of the variable gap working cylinder 2 which 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 out of the cylinder 1, the adjusting sleeve 51 makes the thrust ring 52 move out of 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, 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 adjustment 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 movement of the adjusting sleeve 51 pushes the thrust ring 52 to move through the adjusting column 53. 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 one end of the cylinder 1 away from the cylinder head 4, and the end of the return spring 11 away from the variable clearance adjusting 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 of the sleeve 13 for preventing the floating piston 14 from being separated 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 ear 6 , and the piston rod 32 is threadedly mounted in cooperation with the lifting ear 6 .

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. 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 solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should 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) which 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 cylinder (1) is filled with magnetorheological fluid; the inner wall of the variable gap working cylinder (2) is arranged in a contoured surface and the inner wall 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) comprises a permanent magnet (311) arranged at the end of the piston rod (31) for generating a magnetic field; and the cylinder (1) is provided with an adjustment assembly (5) for adjusting the variable gap working cylinder (2) to move in the cylinder (1).

2. The passive magnetorheological damper with stroke-sensitive damping according to claim 1, characterized in that: 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 clearance working cylinder (2) abuts against the thrust ring (52); the adjusting sleeve (51) is rotated to drive the thrust ring (52) to move so that the adjusting variable clearance working cylinder (2) moves in the cylinder (1).

3. The passive magnetorheological damper with stroke-sensitive damping according to claim 2, characterized in that: A return spring (11) is arranged in the cylinder (1), and two ends of the return spring (11) respectively abut against the inner wall of the cylinder (1) and one end of the variable clearance adjusting working cylinder (2) away from the thrust ring (52).

4. The passive magnetorheological damper with stroke-sensitive damping according to claim 2, characterized in that: The outer wall of the thrust ring (52) is threadedly connected with 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.

5. The passive magnetorheological damper with stroke-sensitive damping according to claim 3, characterized in that: A sleeve (13) is arranged at one end of the cylinder barrel (1) away from the cylinder cover (4), and one end of the return spring (11) away from the variable clearance adjusting working cylinder (2) abuts against the sleeve (13). A floating piston (14) is arranged in the sleeve (13) for maintaining internal pressure balance.

6. The passive magnetorheological damper with stroke-sensitive damping according to claim 5, 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 escaping from the sleeve (13).

7. 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) which are arranged on both sides of the permanent magnet (311).

8. The passive magnetorheological damper with stroke-sensitive damping according to claim 7, 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).

9. The passive magnetorheological damper with stroke-sensitive damping according to claim 8, 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.

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

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