Small magneto-rheological damper

Abstract

The utility model discloses a small magneto-rheological damper, and belongs to the technical field of dampers. The piston rod is connected to the first end of the oil cylinder in a telescopic mode, the piston and the coil are arranged on the piston rod, the magnetorheological fluid is arranged in the oil cylinder, a spring air cylinder is sleeved on the outer side of the second end of the oil cylinder, a movable partition plate is arranged at one end, located in the oil cylinder, of the piston rod, and a fixed partition plate is arranged on the inner wall of the oil cylinder and located between the piston and the movable partition plate. The movable partition plate is in sealed sliding fit with the inner wall of the oil cylinder, the fixed partition plate is in sealed sliding fit with the piston rod, the spring air cylinder is communicated with the second end of the oil cylinder, and inert gas is arranged between the movable partition plate and the fixed partition plate and in the spring air cylinder. Compared with a traditional damper, the damper has the advantages that the damper is shorter, the height of a suspension of a scooter for old people can be effectively reduced, and the convenience and safety of the scooter for old people are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of dampers, in particular to a small magnetorheological damper. Background Art

[0002] To facilitate travel for the elderly, mobility scooters are increasingly available on the market. Typically, dampers are installed on the scooter's suspension to reduce vibration. Existing dampers typically include a return spring, which inevitably increases the length of the damper and, consequently, the height of the scooter's suspension. This, in turn, increases the height of the scooter's seat. This makes getting on and off the scooter more difficult for elderly people with mobility issues, and can even affect their safety. Utility Model Content

[0003] The purpose of this utility model is to solve the problems existing in the above-mentioned prior art and to provide a small magnetorheological damper, which has a shorter length than traditional dampers, can effectively reduce the height of the suspension of the elderly's mobility scooter, and improve the convenience and safety of the elderly's use of the vehicle.

[0004] The purpose of this utility model is achieved through the following technical solutions:

[0005] A small magnetorheological damper includes an oil cylinder, a piston rod telescopically connected to a first end of the oil cylinder, a piston and a coil arranged on the piston rod, and a magnetorheological fluid arranged in the oil cylinder. A spring cylinder is provided on the outer side of the second end of the oil cylinder, a movable partition is provided at one end of the piston rod in the oil cylinder, a fixed partition is provided on the inner wall of the oil cylinder between the piston and the movable partition, the movable partition is in sealing sliding engagement with the inner wall of the oil cylinder, the fixed partition is in sealing sliding engagement with the piston rod, the spring cylinder is connected to the second end of the oil cylinder, and an inert gas is provided between the movable partition and the fixed partition, and in the spring cylinder.

[0006] As a preferred embodiment of the present invention, the inner diameter of the spring cylinder is larger than the outer diameter of the oil cylinder.

[0007] As a preferred embodiment of the present invention, the axial length of the portion of the oil cylinder located inside the spring cylinder is at least 2 / 3 of the axial length of the spring cylinder.

[0008] As a preferred embodiment of the present invention, a limiting nut is provided on the end of the piston rod outside the oil cylinder, and the distance from the limiting nut to the end of the piston rod inside the oil cylinder is less than the axial length of the oil cylinder.

[0009] As a preferred embodiment of the present invention, the piston includes a winding portion in the middle and piston portions at both ends, the piston portion is gap-fitted with the inner wall of the oil cylinder, the diameter of the winding portion is smaller than the diameter of the piston portion, and the coil is wound on the winding portion.

[0010] As a preferred embodiment of the present invention, a lead-in hole is provided at the axis of the piston rod, and threading holes are provided at corresponding positions of the piston rod and the winding portion, and the coil is connected to the outside from the threading hole and the lead-in hole.

[0011] As a preferred embodiment of the present invention, sealant is provided in the lead-in hole and the threading hole.

[0012] As a preferred embodiment of the present invention, the piston is threadedly connected to a piston rod, and positioning nuts are provided on the piston rod at both ends of the piston.

[0013] The advantages of the utility model are:

[0014] 1. A spring cylinder is used instead of a return spring to provide the return power of the piston rod. By increasing the diameter of the spring cylinder, its length is shortened while ensuring the volume of the spring cylinder, thereby shortening the length of the entire damper, effectively reducing the height of the elderly scooter suspension and improving the convenience and safety of the elderly.

[0015] 2. By energizing the coil to generate a magnetic field, the viscosity of the magnetorheological fluid is changed, thereby changing the damping size of the damper to achieve rapid adjustment of the damping size to meet the needs of different users. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A front view of a small magnetorheological damper provided in this embodiment;

[0017] Figure 2 for Figure 1 Cross-sectional view along the AA axis;

[0018] In the figure: 1-oil cylinder; 11-lower oil chamber; 12-upper oil chamber; 2-piston rod; 21-limiting nut; 22-lead hole; 3-piston; 31-winding part; 32-piston part; 4-spring cylinder; 5-movable partition; 6-fixed partition; 71-auxiliary air chamber; 72-main air chamber; 8-positioning nut. DETAILED DESCRIPTION

[0019] The present invention will be described in further detail below with reference to the accompanying drawings and specific implementation methods.

[0020] like Figure 1 and 2As shown, this embodiment provides a small magnetorheological damper, including an oil cylinder 1, a piston rod 2 telescopically connected to the upper end of the oil cylinder 1, a piston 3 and a coil arranged on the piston rod 2, and a magnetorheological fluid arranged in the oil cylinder 1. The outer side of the lower end of the oil cylinder 1 is provided with a spring cylinder 4, the lower end of the piston rod 2 is provided with a movable partition 5, and a fixed partition 6 is provided on the inner wall of the oil cylinder 1 between the piston 3 and the movable partition 5. The movable partition 5 is sealingly slidably matched with the inner wall of the oil cylinder 1, and the fixed partition 6 is sealingly slidably matched with the piston rod 2. The spring cylinder 4 is connected to the lower end of the oil cylinder 1, and an inert gas, generally nitrogen, is provided between the movable partition 5 and the fixed partition 6, and in the spring cylinder 4. Thus, above the fixed partition 6 are oil chambers, namely the lower oil chamber 11 below the piston 3 and the upper oil chamber 12 above the piston 3. Below the fixed partition 6 are air chambers, namely the auxiliary air chamber 71 between the fixed partition 6 and the movable partition 5, and the main air chamber 72 between the movable partition 5 and the spring cylinder 4. In the initial state, the air pressure in the main air chamber 72 and the auxiliary air chamber 71 is balanced. The working principle of this damper is as follows:

[0021] When piston rod 2 is compressed downward, piston 3 moves downward, reducing the volume of lower oil chamber 11 while increasing the volume of upper oil chamber 12. The magnetorheological fluid must flow from lower oil chamber 11 through the gap between piston 3 and the inner wall of the cylinder into upper oil chamber 12. As the magnetorheological fluid flows through the gap between the piston and the inner wall of the cylinder, damping is generated. Simultaneously, during this process, movable diaphragm 5 moves downward, reducing the volume of main air chamber 72 and increasing the pressure, while auxiliary air chamber 71 increases and decreases the pressure. When external compression of piston rod 2 ends, because the pressure in main air chamber 72 is greater than that in auxiliary air chamber 71, the inert gas pushes movable diaphragm 5 and piston rod 2 upward until the pressures in main and auxiliary air chambers 72 and 71 reach equilibrium, at which point piston rod 2 returns to its initial position.

[0022] When the piston rod 2 is stretched upward, the piston 3 moves upward, increasing the volume of the lower oil chamber 11 while decreasing the volume of the upper oil chamber 12. The magnetorheological fluid must flow from the upper oil chamber 12 through the gap between the piston 3 and the inner wall of the cylinder into the lower oil chamber 11. As the magnetorheological fluid flows through the gap between the piston and the inner wall of the cylinder, damping is generated. Simultaneously, during this process, the movable diaphragm 5 moves upward, increasing the volume of the main air chamber 72 and reducing the air pressure, while the volume of the auxiliary air chamber 71 decreases and the air pressure increases. When the external stretching of the piston rod 2 ends, because the air pressure in the main air chamber 72 is lower than that in the auxiliary air chamber 71, the inert gas pushes the movable diaphragm 5 and the piston rod 2 downward until the air pressure in the main and auxiliary air chambers 72 and 71 reaches equilibrium, at which point the piston rod 2 returns to its initial position.

[0023] In this way, under the premise of maintaining the performance of the damper, the spring cylinder 4 is used to replace the original spring, and the spring cylinder 4 can be expanded laterally to shorten the length, thereby shortening the length of the entire damper. It is particularly suitable for elderly people's mobility scooters that need to lower the suspension height, improving the convenience and safety of the elderly in using the car.

[0024] Specifically, the inner diameter of the spring cylinder 4 is larger than the outer diameter of the oil cylinder 1. This increases the diameter while maintaining the required volume, thereby shortening the length. To prevent the excessively large diameter of the spring cylinder 4 from compromising assembly, the axial length of the portion of the oil cylinder 1 within the spring cylinder 4 is at least two-thirds of the axial length of the spring cylinder 4, fully utilizing the longitudinal space near the outer wall of the oil cylinder. Of course, the lower end of the oil cylinder 1 needs to be sufficiently clear of the inner bottom surface of the spring cylinder, for example, 1 cm, to ensure smooth gas flow and efficient return of the piston rod 2.

[0025] In order to prevent the movable partition 5 from exceeding the lower end of the cylinder 1 when the piston rod 2 moves downward, a limit nut 21 is provided at the upper end of the piston rod 2, and the distance from the limit nut 21 to the lower end of the piston rod 2 is smaller than the axial length of the cylinder 1, so as to utilize the limit cooperation between the limit nut 21 and the upper end of the cylinder to ensure that the movable partition 5 is always in the cylinder.

[0026] Since this damper uses magnetorheological fluid and a coil, the size of the magnetic field generated by the coil can be changed by changing the current flowing through the coil, thereby adjusting the viscosity of the magnetorheological fluid and achieving the purpose of adjusting the damping size. Therefore, in order to facilitate the installation of the coil, the piston 3 includes a winding portion 31 in the middle and piston portions 32 at both ends. The piston portion 32 is fitted with a gap between the inner wall of the cylinder 1. According to industry requirements, the gap size is 1 mm. The diameter of the winding portion 31 is smaller than the diameter of the piston portion 32, and the coil is wound on the winding portion 31. That is, the coil is limited between the upper and lower piston portions 32, and the position is more stable. Moreover, due to the limiting relationship between the upper piston portion and the upper end of the cylinder, it can be ensured that the coil is always in the cylinder 1, and the magnetic field generated by it can stably act on the magnetorheological fluid in the cylinder.

[0027] To facilitate coil wiring, a lead hole 22 is provided at the axis of the piston rod 2. Threading holes are also provided at corresponding locations on the piston rod 2 and the winding portion 31. The coil is connected to the outside through these threading holes and lead hole 22. To ensure sealing and prevent the magnetorheological fluid from escaping through these holes, sealant is placed inside the lead hole 22 and the threading hole.

[0028] Finally, to facilitate installation of the piston 3, it is threadedly connected to the piston rod 2. Positioning nuts 8 are provided on both ends of the piston rod 2. The positioning nuts 8, piston 3, and positioning nuts 8 are then screwed onto the piston rod 2 in sequence. The position of the piston 3 is then adjusted until the threading holes on the piston 3 align with those on the piston rod 2. At this point, the two positioning nuts 8 are tightened toward one side of the piston 3 to ensure the stability of the piston position. Wire winding and threading can then be performed.

[0029] The above is only a preferred embodiment of the present invention, which is one implementation method based on the overall concept of the present invention. The scope of protection of the present invention is not limited to this embodiment. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A small magnetorheological damper, comprising an oil cylinder, a piston rod telescopically connected to a first end of the oil cylinder, a piston and a coil arranged on the piston rod, and a magnetorheological fluid arranged in the oil cylinder, characterized in that: A spring cylinder is sleeved on the outer side of the second end of the oil cylinder, a movable partition is provided at one end of the piston rod in the oil cylinder, a fixed partition is provided on the inner wall of the oil cylinder between the piston and the movable partition, the movable partition is slidingly matched with the inner wall of the oil cylinder in a sealing manner, the fixed partition is slidingly matched with the piston rod in a sealing manner, the spring cylinder is connected to the second end of the oil cylinder, and inert gas is provided between the movable partition and the fixed partition, and in the spring cylinder.

2. A small magnetorheological damper according to claim 1, characterized in that: The inner diameter of the spring cylinder is greater than the outer diameter of the oil cylinder.

3. A small magnetorheological damper according to claim 1, characterized in that: The axial length of the portion of the oil cylinder located inside the spring cylinder is at least 2 / 3 of the axial length of the spring cylinder.

4. A small magnetorheological damper according to claim 1, characterized in that: A limiting nut is provided on one end of the piston rod outside the oil cylinder, and the distance from the limiting nut to the end of the piston rod inside the oil cylinder is less than the axial length of the oil cylinder.

5. A small magnetorheological damper according to claim 1, characterized in that: The piston comprises a winding part in the middle and piston parts at both ends. The piston part is in clearance fit with the inner wall of the oil cylinder. The diameter of the winding part is smaller than the diameter of the piston part. The coil is wound on the winding part.

6. A small magnetorheological damper according to claim 5, characterized in that: The axis of the piston rod is provided with a lead-in hole, and the piston rod and the winding part are provided with threading holes at corresponding positions, and the coil is connected to the outside from the threading hole and the lead-in hole.

7. A small magnetorheological damper according to claim 6, characterized in that: Sealant is arranged in the lead-in hole and the threading hole.

8. A small magnetorheological damper according to claim 6, characterized in that: The piston is threadedly connected to a piston rod, and positioning nuts are provided on both ends of the piston on the piston rod.

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