A method for calculating a moving piston, a magnetorheological damper, and a magnetic circuit.

Abstract

This invention discloses a movable piston, a magnetorheological damper, and a magnetic circuit calculation method. The movable piston includes an outer casing, an iron core, a coil, a magnetic guide ring, and a magnetic resisting ring. The iron core is fitted and fixed on the piston rod. An annular coil groove is formed on the outer wall of the iron core, and a coil is placed in the coil groove. The outer casing is fitted over the iron core, and a damping channel is formed between the outer casing and the iron core at intervals. The magnetic guide ring is fitted over the coil. The number of magnetic resisting rings is odd. Some magnetic resisting rings are intermittently embedded on the magnetic guide ring, and the remaining magnetic resisting rings are intermittently embedded on the outer casing, and are staggered from the magnetic resisting rings on the magnetic guide ring. The magnetorheological damper uses this movable piston. The magnetic circuit calculation method is used to calculate the magnetic circuit of the movable piston. This magnetic circuit can increase the effective working length of the damping channel, increase the output damping force of the magnetorheological damper, and reduce the leakage magnetic problem of the magnetorheological damper, thereby improving the energy utilization rate of the input current.

Description

Technical Field

[0001] This invention relates to the field of vibration damper technology, specifically to a moving piston, a magnetorheological vibration damper, and a magnetic circuit calculation method. Background Technology

[0002] Magnetorheological dampers have the characteristics of controllable damping, fast response, and wide adjustable range, and have become one of the research hotspots in vibration suppression technology in recent years. Their basic principle is to change the magnitude of the current in the coil, thereby changing the magnetic field strength in the damping channel, and then changing the shear yield strength of the magnetorheological fluid, ultimately achieving the purpose of changing the output damping force of the damper. However, ordinary magnetorheological dampers have a short effective working length of damping channel, and often the output damping force is very small and the adjustable range is not large.

[0003] Traditional magnetorheological dampers with curved magnetic circuits force the magnetic field to shuttle back and forth in the damping channel, which can effectively increase the effective working length of the damping channel, improve the output damping force of the magnetorheological damper, and expand the adjustable range. However, magnetic leakage inevitably occurs during the bending process of the magnetic circuit, resulting in low utilization of input electrical energy and small output damping force of the magnetorheological damper. These problems seriously limit the practical engineering application of magnetorheological dampers.

[0004] To improve the effective working length of the damping channel of the magnetorheological damper, increase the output damping force of the magnetorheological damper, reduce the leakage flux problem of the magnetorheological damper, improve the energy utilization rate of the input current, and better facilitate engineering applications, the above problems urgently need to be solved. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the technical problem to be solved by this invention is to provide a moving piston, a magnetorheological damper, and a magnetic circuit calculation method, which can increase the effective working length of the damping channel, increase the output damping force of the magnetorheological damper, and at the same time reduce the leakage magnetic problem of the magnetorheological damper, thereby improving the energy utilization rate of the input current.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: a magnetorheological vibration damper, wherein the movable piston includes an outer cover, an iron core, a coil, a magnetic guide ring, and a magnetic resisting ring, characterized in that the iron core is sleeved and fixed on the piston rod, an annular coil groove is formed on the outer wall of the iron core, the coil is disposed in the coil groove, the outer cover is sleeved on the iron core and a damping channel is formed between the outer cover and the iron core at intervals, the magnetic guide ring is sleeved on the coil, the number of magnetic resisting rings is odd, some of the magnetic resisting rings are intermittently embedded on the magnetic guide ring, and the remaining magnetic resisting rings are intermittently embedded on the outer cover and are staggered from the magnetic resisting rings on the magnetic guide ring.

[0007] Furthermore, the number of the magnetic blocking rings embedded in the magnetic conductive ring is odd.

[0008] Furthermore, the magnetic ring has the same cross-sectional shape along its axial direction.

[0009] Furthermore, the magnetic ring material is selected from ferromagnetic metal materials with a relative permeability greater than 1, and the magnetic blocking ring material is selected from diamagnetic metal materials with a relative permeability less than 1.

[0010] A magnetorheological vibration damper, comprising:

[0011] cylindrical body;

[0012] A floating piston is slidably installed inside the cylinder to divide the cylinder cavity into a gas cavity and a liquid cavity. The gas cavity contains gas, and the liquid cavity contains magnetorheological fluid.

[0013] The aforementioned piston assembly is slidably mounted within the liquid chamber, dividing the liquid chamber into an upper liquid chamber and a lower liquid chamber. The damping channel of the piston assembly connects the upper liquid chamber and the lower liquid chamber.

[0014] The piston rod extends from the outside of the cylinder into the upper liquid chamber and connects to the piston assembly.

[0015] Furthermore, the cylinder body includes a cylindrical body, an upper end cover, and a lower end cover, the upper end cover and the lower end cover being threadedly connected to the cylindrical body.

[0016] Furthermore, a sealing ring is used for dynamic sealing between the piston rod and the upper end cover.

[0017] Furthermore, the piston rod is guided by a guide seat.

[0018] A magnetic circuit calculation method for calculating the aforementioned moving piston includes:

[0019] Based on the characteristics of magnetic circuit shunting and bending, the moving piston is divided into several regions;

[0020] Calculate the magnetic flux in each region and the magnetic flux in the damped channel;

[0021] Based on the structural constraints of the moving piston, the region that first reaches magnetic saturation is analyzed.

[0022] Based on the saturation magnetic flux density of the region that first reaches magnetic saturation and the law of conservation of magnetic flux, the magnetic flux density of each region and the magnetic flux density of the damping channel are calculated.

[0023] Based on the calculation results, the positions of the magnetic guide ring and the magnetic resisting ring of the magnetorheological damper are adjusted, thereby adjusting the position of magnetic circuit bending and current shunting, so that magnetic saturation does not occur in each region, and the magnetic flux of the damping channel is maximized.

[0024] Furthermore, the magnetic flux in each region was calculated using Ampere's circuital law and Gauss's law.

[0025] The beneficial effects of this invention are:

[0026] The magnetic circuit in the aforementioned moving piston, magnetorheological damper, and magnetic circuit calculation method, during operation, first undergoes current shunting guided by a magnetic guide ring, then is combined with a magnetic resisting ring to force the shunted portion of the magnetic circuit to bend. This combination of the magnetic guide and resisting rings causes the magnetic circuit to repeatedly pass through the damping channel, resulting in a longer effective working length of the damping channel. This allows for effective full-path damping, thus enabling a larger output damping force and adjustable range within the same structural size constraints. Furthermore, this novel magnetic circuit shuns the magnetic circuit before bending, effectively reducing magnetic leakage and improving the energy utilization rate of the input current. In addition, the magnetic circuit of this magnetorheological damper is easy to implement, meets the requirements of vibration damping equipment for resisting vibration and impact, and has high practical application value. Attached Figure Description

[0027] To more clearly illustrate the specific embodiments of the present invention, the accompanying drawings used in the specific embodiments will be briefly described below. In all the drawings, the elements or parts are not necessarily drawn to scale.

[0028] Figure 1 This is a schematic diagram of a magnetorheological vibration damper provided in an embodiment of the present invention;

[0029] Figure 2 for Figure 1 The image shown is a cross-sectional view of a magnetorheological vibration damper.

[0030] Figure 3 for Figure 2 A partial schematic diagram of point A in the middle;

[0031] Figure 4 A piston magnetic circuit distribution diagram in a magnetorheological vibration damper provided in an embodiment of the present invention;

[0032] Figure 5 This is a schematic diagram of the piston magnetic circuit division region in a magnetorheological vibration damper according to an embodiment of the present invention;

[0033] Figure 6 The images show a comparison of magnetic field line distributions, including (a) a conventional magnetorheological damper, (b) a magnetorheological damper with a meandering magnetic path (preliminary document), and (c) a magnetorheological damper provided in an embodiment of the present invention.

[0034] Figure 7The images show a comparison of magnetic field strength distributions, including (a) a conventional magnetorheological damper, (b) a magnetorheological damper with a meandering magnetic circuit (preliminary document), and (c) a magnetorheological damper provided in an embodiment of the present invention.

[0035] Figure 8 for Figure 1 A comparison diagram of magnetic field strength at the damping channel in a magnetorheological vibration damper provided in an embodiment of the present invention.

[0036] Figure label:

[0037] 100. Cylinder body; 110. Shell body; 120. Upper end cover; 130. Lower end cover; 200. Floating piston; 300. Moving piston; 310. Outer cover; 320. Iron core; 330. Coil; 340. Magnetic ring; 350. Magnetic blocking ring; 360. Damping channel; 370. Magnetic circuit; 400. Piston rod; 500. Guide seat. Detailed Implementation

[0038] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0039] Please see Figures 1 to 8 This invention provides a magnetorheological vibration damper; please refer to [link / reference]. Figure 1 and Figure 2 One embodiment of the magnetorheological damper includes a cylinder 100, a floating piston 200, a movable piston 300, and a piston rod 400.

[0040] A floating piston 200 is slidably mounted inside the cylinder 100, dividing the cylinder 100 into a gas chamber and a liquid chamber. The gas chamber contains gas, and the liquid chamber contains magnetorheological fluid. A movable piston 300 is slidably mounted inside the liquid chamber, dividing the liquid chamber into an upper liquid chamber and a lower liquid chamber. The damping channel 360 of the movable piston 300 connects the upper and lower liquid chambers. A piston rod 400 extends from outside the cylinder 100 into the upper liquid chamber and connects to the movable piston 300.

[0041] When the magnetorheological damper is subjected to external vibration and impact, the piston rod 400 drives the movable piston 300 to move relative to the cylinder 100 under the action of vibration force. The movable piston 300 moves up and down in the liquid chamber, continuously squeezing the magnetorheological fluid through the damping channel 360 in the movable piston 300 to flow in the upper and lower liquid chambers, thereby converting the kinetic energy generated by external vibration and impact into heat energy for dissipation, achieving the purpose of vibration reduction. During the back-and-forth movement of the movable piston 300 in the liquid chamber, due to the presence of the piston rod 400, there is a volume difference in the magnetorheological fluid flowing through the upper and lower liquid chambers during the movement of the movable piston 300. This needs to be compensated, which is achieved by the back-and-forth movement of the floating piston 200 in the cylinder 100.

[0042] In this embodiment, to facilitate the assembly and disassembly of the floating piston 200 and the movable piston 300, the cylinder body 100 includes a cylindrical body 110, a lower end cover 130, and an upper end cover 120. The floating piston 200 and the movable piston 300 are slidably disposed inside the cylindrical body 110. The upper end cover 120 and the lower end cover 130 are respectively installed at both ends of the cylindrical body 110 to close both ends of the cylindrical body 110. The piston rod 400 passes through the upper end cover 120 and extends out of the cylinder body 100.

[0043] Based on the above embodiments, the upper end cover 120 and the lower end cover 130 are further detachably connected to the end of the cylinder 110 via threads and are statically sealed by a sealing ring. A sealing ring is used for dynamic sealing between the piston rod 400 and the upper end cover 120. A guide seat 500 is provided inside the upper end cover 120, which guides the piston rod 400.

[0044] In one embodiment, the gas chamber is filled with high-pressure nitrogen gas, which, together with the floating piston 200, forms a nitrogen spring compensation mechanism. Volume compensation is achieved by the back-and-forth movement of the floating piston 200 within the cylinder 100. It is understood that in other embodiments, the gas chamber may also be filled with other stable gases, such as air, to achieve volume compensation by moving the floating piston 200 within the cylinder 100.

[0045] Please see Figure 2 and Figure 3The movable piston 300 provided by the present invention includes an outer cover 310, an iron core 320, a coil 330, a magnetic ring 340, and a magnetic blocking ring 350. The iron core 320 is sleeved and fixed on the piston rod 400. An annular groove for the coil 330 is formed on the outer wall of the iron core 320, and a coil 330 is disposed in the groove. The outer cover 310 is sleeved on the iron core 320, and a damping channel 360 is formed between the outer cover 310 and the iron core 320 at intervals. The magnetic ring 340 is sleeved on the coil 330. The number of magnetic blocking rings 350 is odd. Some of the magnetic blocking rings 350 are embedded in the magnetic ring 340 at intervals, and the remaining magnetic blocking rings 350 are embedded in the outer cover 310 at intervals, and are staggered from the magnetic blocking rings 350 on the magnetic ring 340.

[0046] In this movable piston 300, the magnetic circuit 370 first undergoes current shunting guided by the magnetic guide ring 340, and then, in conjunction with the magnetic resisting ring 350, forces the shunted portion of the magnetic circuit 370 to bend. That is, through the combination of the magnetic guide ring 340 and the magnetic resisting ring 350, the magnetic circuit 370 repeatedly passes through the damping channel 360, thus achieving a longer effective working length of the damping channel 360. This allows for full effectiveness of the damping channel 360, resulting in a larger output damping force and adjustable range within the same structural size constraints. Simultaneously, this novel magnetic circuit 370 can shun the magnetic circuit 370 before it bends, effectively reducing magnetic leakage and improving the energy utilization rate of the input current. Furthermore, the magnetic circuit of this magnetorheological vibration damper is easy to implement and can meet the requirements of vibration damping equipment for resisting vibration and impact.

[0047] In this embodiment, the number of magnetic blocking rings 350 embedded in the magnetic conducting ring 340 is odd, and the remaining magnetic blocking rings 350 embedded in the outer cover 310 are even.

[0048] For example: If there are a total of 3 magnetic blocking rings 350, then 2 magnetic blocking rings 350 are placed at intervals on the magnetic conducting rings 340, and the remaining magnetic blocking ring 350 is placed on the outer cover 310, between the 2 magnetic blocking rings 350 on the magnetic conducting rings 340, and so on. If there are a total of 5 magnetic blocking rings 350, then 3 magnetic blocking rings 350 are placed at intervals on the magnetic conducting rings 340, and the remaining 2 magnetic blocking rings 350 are placed on the outer cover 310, staggered from the 3 magnetic blocking rings 350 on the magnetic conducting rings 340, and so on.

[0049] Using this configuration, a magnetic circuit 370 that first splits and then bends can be formed within the moving piston 300, allowing the magnetic circuit 370 to shuttle back and forth within the damping channel 360 (see...). Figure 4Specifically, the number of times the magnetic field lines pass through the damping channel 360 is equal to the number of magnetic blocking rings 350 plus one. If there are 3 magnetic blocking rings 350 in the moving piston 300, the magnetic circuit 370 bends 4 times under the action of the magnetic blocking rings 350 isolating the magnetic circuit. If there are 5 magnetic blocking rings 350 in the moving piston 300, the magnetic circuit 370 bends 6 times under the action of the magnetic blocking rings 350 isolating the magnetic circuit. If 7 magnetic blocking rings 350 are used in the moving piston 300, the magnetic circuit 370 bends 8 times under the action of the magnetic blocking rings 350 isolating the magnetic circuit, and so on.

[0050] In practical implementation, the cross-sectional shape of the magnetic ring 340 can be made uniform along its axial direction for ease of processing. Furthermore, making the magnetic ring 340 a single piece reduces the number of times it needs to be installed. In addition, the core 320 is made of a ferromagnetic material with a relative permeability greater than 1, such as iron, cobalt, nickel, or their alloys. The magnetic ring 340 should be made of a ferromagnetic metal with a relative permeability greater than 1, while the magnetic blocking ring 350 should be made of a diamagnetic metal with a relative permeability less than 1.

[0051] Electromagnetic finite element analysis was performed using Ansoft Maxwell finite element software. The magnetorheological damper of this invention was compared with the magnetic circuit 370 of a magnetorheological damper with a conventional magnetic circuit and the magnetic circuit 370 of the magnetorheological damper in the patent with publication number CN106402255A entitled "Magneticrheological Damper with Winding Magnetic Circuit Characteristics". The three magnetorheological dampers use the same structural dimensions and materials, and the same input current. In this example, the core 320 is made of electrical pure iron DT4, the piston outer cover 310, piston rod 400, and magnetic ring 340 are all made of 45 steel, the magnetic ring 350 is made of copper, and the coil 330 is made of enameled copper wire.

[0052] like Figure 5 The magnetic circuit distribution diagram of the piston of this magnetorheological vibration damper is shown. The structure of the moving piston 300 is divided into several regions, the magnetic flux of each region is calculated, and the magnetic induction intensity of each region is calculated according to the characteristics of the moving piston 300 and the law of conservation of magnetic flux.

[0053] In one of the examples, such as Figure 5As shown, the movable piston 300 structure is divided into 10 regions, denoted as A1 to A10. The magnetic field lines pass through the damping channel 360 4 times. Due to the structural size limitations of the magnetic ring 340 within the coil slot, region A7 reaches magnetic saturation first. Based on the saturation magnetic induction intensity of material A7 and the law of conservation of magnetic flux, the magnetic induction intensity of other regions can be calculated. Furthermore, A1 (A4) and A2 (A3) are made of the same material, and A1 (A4) has a larger magnetic flux area. Also, fewer magnetic field lines pass through A1 (A4) than A2 (A3). Therefore, magnetic saturation will not occur at A1 (A4), and similarly, magnetic saturation will not occur in A6 and A8.

[0054] like Figure 6 The image shows a comparison of the magnetic field line distribution of the magnetorheological vibration dampers with the above three different magnetic circuits. Figure 6 As can be seen from (a): in the magnetorheological damper with a traditional magnetic circuit, there is basically no magnetic field line distribution near the damping channel, the magnetic field lines are distributed at both ends of the damping channel, and the effective working length of the damping channel is short. From Figure 6 As can be seen in (b): In the comparative document (CN106402255A), the magnetorheological damper with a meandering magnetic circuit has magnetic lines distributed in the full damping channel. The effective working length of the damping channel is long, and the entire channel is effective. However, some magnetic lines at the magnetic blocking ring directly pass through the magnetic blocking ring to form a closed loop, which has a serious magnetic leakage problem.

[0055] And from Figure 6 As can be seen from (c), in the magnetorheological damper of the present invention, magnetic field lines are distributed throughout the entire damping channel 360. The effective working length of the damping channel 360 is long, enabling full-channel effectiveness without significant magnetic leakage. Based on the comparison of magnetic field line distribution, it can be seen that the novel magnetic circuit 370 of the magnetorheological damper of the present invention can achieve full-channel effectiveness without significant magnetic leakage. Its magnetic field line distribution is superior to that of traditional magnetorheological dampers and the magnetorheological damper with a meandering magnetic circuit in the prior art (CN106402255A).

[0056] like Figure 7 He Ru Figure 8The image shows a comparison of the magnetic field strength distribution of three types of magnetorheological dampers. It can be seen that the magnetic field strength of the damping channel in the magnetorheological damper with a traditional magnetic circuit is only distributed at both ends of the damping channel, with almost zero magnetic field strength near the coil, representing an ineffective working length. The average magnetic field strength of the damping channel is 16.91 kA / m. In contrast, the magnetorheological damper with a meandering magnetic circuit in the comparison document (CN106402255A) has a magnetic field strength between 10 kA / m and 12 kA / m in the damping channel near the coil. The entire damping channel has a magnetic field distribution, essentially achieving full channel effectiveness. The average magnetic field strength of the damping channel is 22.83 kA / m. The magnetic field strength distribution of the damping channel is somewhat improved compared to the magnetorheological damper with a traditional magnetic circuit, but the magnetic field strength is still mainly distributed at both ends of the damping channel, and the improvement is not significant.

[0057] The magnetic field strength of the damping channel of this magnetorheological vibration damper is between 18kA / m and 36kA / m. The entire damping channel has a magnetic field distribution, which is more evenly distributed, and can achieve full channel effectiveness. The average magnetic field strength of the entire damping channel is 33.97kA / m. The magnetic field strength distribution is significantly better than that of magnetorheological vibration dampers with traditional magnetic circuits and magnetorheological vibration dampers in the prior art (CN106402255A).

[0058] The finite element simulation analysis shows that the magnetic field line distribution and magnetic field strength distribution of the proposed magnetorheological damper are significantly better than those of magnetorheological dampers with traditional magnetic circuits and those with meandering magnetic circuits in the comparative document (CN106402255A). The magnetic field strength of the damping channel of the magnetorheological damper is positively correlated with the magnitude of the output damping force. Therefore, this magnetorheological damper not only increases the effective working length of the damping channel by 360°, achieving full-channel effectiveness, but also effectively reduces magnetic leakage and improves the energy utilization rate of the input current. Under the same structural dimensions, materials, and input current, it can have a greater output damping force, better meeting the actual needs of vibration damping equipment in resisting vibration and impact, and has high engineering application value.

[0059] The present invention also provides a magnetic circuit calculation method, which is used to calculate the magnetic circuit 370 in the above-mentioned magnetorheological damper, and includes the following steps:

[0060] S110. Based on the characteristics of the 370-degree current split and bending of the magnetic circuit, the movable piston is divided into several regions.

[0061] S120. Calculate the magnetic flux in each region and the magnetic flux in the damping channel 360.

[0062] S130. Based on the structural constraints of the moving piston, the region that first reaches magnetic saturation is analyzed.

[0063] S140. Based on the saturation magnetic induction intensity of the region that first reaches magnetic saturation and the law of conservation of magnetic flux, calculate the magnetic induction intensity of each region and the magnetic induction intensity of the damping channel 360.

[0064] S150. Based on the calculation results, adjust the positions of the magnetic guide ring 340 and the magnetic deflector ring 350 of the magnetorheological damper, thereby adjusting the positions of magnetic circuit bending and current shunting to prevent magnetic saturation in each region and maximize the magnetic flux of the damping channel 360.

[0065] The specific calculation process is as follows:

[0066] Figure 5 As shown, the movable piston is divided into 10 regions, denoted as A1 to A10, and the magnetic flux in each region is:

[0067]

[0068] φ2=φ3=B2S2=B2π(R 2 -R3 2 (2)

[0069] φ5=φ9=B5S5=B5π(R1+R2)L a (3)

[0070] φ6=φ8=B6S6=B6π(R2 2 -(R2-L d ) 2 (4)

[0071] φ7=B7S7=B7π(R2 2 -(R2-L d ) 2 (5)

[0072] φ 10 =B 10 S 10 =B 10 πR1 2 (6)

[0073] In the formula, R is defined as the outer radius of the piston casing 310, r is the radius of the piston rod 400, R1 is the inner radius of the coil 330 slot, R2 is the radius of the iron core 320, R3 is the outer radius of the piston casing 310, h is the width of the damping channel 360, and L... a L is the length of both ends of the 320 iron core. b L is the length of the 330 slots of the coil, and L is the total length of the 360 ​​damping channel. c The maximum width of the piston's outer middle magnetic ring is 350 mm, L d The thickness of the magnetic ring is 340, φ i(i = 1, 2, ..., 10) represents the magnetic flux through each region, B i S represents the corresponding magnetic flux density. i This represents the corresponding magnetic flux area.

[0074] The magnetic flux of the damping channel 360 is:

[0075] φ f =B f S f =B f π(R²+R³)L (7)

[0076] In the formula, φ f B f and S f These represent the magnetic flux, magnetic induction intensity, and magnetic flux area at 360° of the damping channel, respectively.

[0077] When the number of magnetic isolation rings 350 is 3, the magnetic circuit 370 bends 4 times. At this time, according to the characteristics of current shunting and bending in the magnetic circuit 370, the number of times the magnetic lines of force pass through the damping channel 360 is the number of magnetic isolation rings + 1. All the magnetic lines of force pass through the damping channel 360 4 times. Therefore, according to the conservation of magnetic flux, the magnetic flux relationship of each region can be obtained as follows:

[0078]

[0079] like Figure 5 As shown, due to the size limitation of the magnetic ring 340 installed in the slot of coil 330, the magnetic flux area of ​​A7 is relatively small. However, A7 must pass through all the magnetic flux, so A7 is most prone to magnetic saturation. To maximize the magnetic induction intensity of the damping channel 360 while avoiding magnetic saturation, the magnetic induction intensity of A7 is chosen as its saturation value B. 7max The magnetic induction intensity B at 360° of the damping channel f for:

[0080]

[0081] Similarly, the magnetic induction intensities of A2, A3, A5, A7, A9, and A10 can be obtained.

[0082] like Figure 5 As shown, since A1 (A4) and A2 (A3) are made of the same material and A1 (A4) has a larger magnetic flux area, and furthermore, due to the 370° current shunting and bending characteristics of the magnetic circuit, fewer magnetic field lines pass through A1 (A4) than A2 (A3). Therefore, magnetic saturation will not occur at A1 (A4). Similarly, the magnetic induction intensity of A6 and A8 must be less than that of A7, and magnetic saturation will not occur in A6 and A8.

[0083] Finally, based on the calculation results, the positions of the magnetic guide ring 340 and the magnetic resistive ring of the magnetorheological damper are adjusted, thereby adjusting the bending and shunting positions of the magnetic circuit 370, so that magnetic saturation does not occur in each region, and the magnetic flux of the damping channel 360 is maximized.

[0084] It should be noted that the magnetic flux in each region can be calculated using Ampere's circuital law and Gauss's law.

[0085] This magnetic circuit theory calculation method has the following advantages:

[0086] This magnetic circuit theory calculation method divides the piston into several regions to determine the region that reaches magnetic saturation first, thus avoiding magnetic saturation in different regions of the piston, ensuring maximum energy utilization, and preventing energy waste.

[0087] This method is simple and clear, applicable to the piston magnetic circuit 370 design stage of magnetorheological dampers, and has high practical engineering application value.

[0088] 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 the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A movable piston, the movable piston comprising an outer casing, an iron core, a coil, a magnetic conducting ring, and a magnetic blocking ring, characterized in that, The iron core is fixed on the piston rod. An annular coil groove is formed on the outer wall of the iron core, and the coil is placed in the coil groove. The outer cover is fitted on the iron core and a damping channel is formed between it and the iron core at intervals. The magnetic ring is fitted on the coil. The number of magnetic rings is odd. Some of the magnetic rings are embedded on the magnetic ring at intervals, and the remaining magnetic rings are embedded on the outer cover at intervals, and are staggered from the magnetic rings on the magnetic ring.

2. The movable piston according to claim 1, characterized in that, The number of magnetic blocking rings embedded in the magnetic conducting ring is odd.

3. The movable piston according to claim 1, characterized in that, The magnetic rings have the same cross-sectional shape along their axial direction.

4. The movable piston according to claim 2, characterized in that, The magnetic ring material is selected from ferromagnetic metal materials with a relative permeability greater than 1, and the magnetic blocking ring material is selected from diamagnetic metal materials with a relative permeability less than 1.

5. A magnetorheological vibration damper, characterized in that, include: Cylinder body, the cylinder body including a cylindrical body; A floating piston is slidably installed inside the cylinder to divide the cylinder cavity into a gas cavity and a liquid cavity. The gas cavity contains gas, and the liquid cavity contains magnetorheological fluid. The movable piston according to any one of claims 1-4 is slidably installed in the liquid chamber, the movable piston divides the liquid chamber into an upper liquid chamber and a lower liquid chamber, and the damping channel of the movable piston connects the upper liquid chamber and the lower liquid chamber; and The piston rod extends from the outside of the cylinder into the upper liquid chamber and is connected to the movable piston.

6. The magnetorheological vibration damper according to claim 5, characterized in that, The cylinder body also includes an upper end cover and a lower end cover, which are connected to the cylinder body by threads.

7. The magnetorheological vibration damper according to claim 5, characterized in that, The piston rod and the upper end cover are dynamically sealed using a sealing ring.

8. The magnetorheological vibration damper according to claim 5, characterized in that, The piston rod is guided by a guide seat.

9. A method for calculating magnetic circuits, characterized in that, The method for calculating the magnetic circuit in the movable piston as described in claim 1 includes: Based on the characteristics of magnetic circuit shunting and bending, the moving piston is divided into several regions; Calculate the magnetic flux in each region and the magnetic flux in the damped channel; Based on the structural constraints of the moving piston, the region that first reaches magnetic saturation is analyzed. Based on the saturation magnetic flux density of the region that first reaches magnetic saturation and the law of conservation of magnetic flux, the magnetic flux density of each region and the magnetic flux density of the damping channel are calculated. Based on the calculation results, the positions of the magnetic guide ring and the magnetic resisting ring of the magnetorheological damper are adjusted, thereby adjusting the position of magnetic circuit bending and current shunting, so that magnetic saturation does not occur in each region, and the magnetic flux of the damping channel is maximized.

10. The magnetic circuit calculation method according to claim 9, characterized in that, The magnetic flux in each region was calculated using Ampere's circuital law and Gauss's law.

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