Elevator vibration isolator based on magnetorheological elastomer

Abstract

The invention discloses an elevator vibration isolator based on a magnetorheological elastomer, and belongs to the field of magnetorheological dampers. The vibration isolator is mainly composed of a magnetorheological elastomer, a pressure sensor, an end cover, a spring and a magnet exciting coil, the end cover and the spring are made of magnetic conductive materials, the pressure sensor of the vibration isolator is located in the middle of the interior of the magnetorheological elastomer, the upper portion and the lower portion of the pressure sensor are connected with the spring, and it is guaranteed that the magnet exciting coil is located in the middle of the magnetorheological elastomer all the time when extruded; and the damping of the magnetorheological elastomer is favorably changed. According to the vibration isolator, the pressure sensor is used for sensing the pressure of vibration, automatic adjustment of damping of the vibration isolator is achieved, and the vibration isolator is simple in structure, small in size, low in energy consumption and large in bearing capacity.

Description

TECHNICAL FIELD

[0001] The present application relates to an elevator vibration isolator, in particular to an elevator vibration isolator based on magneto-rheological elastomer. BACKGROUND

[0002] During the operation of the elevator, vibration problem has always been one of the key factors affecting the performance and ride comfort of the elevator. The traditional elevator vibration isolator has many shortcomings in dealing with complex and variable vibration conditions.

[0003] With the continuous increase of modern building height and the improvement of elevator running speed, the vibration impact on the elevator car during operation is more complex, including inertia impact during starting and stopping, and vibration caused by factors such as guide rail unevenness and rope tension change. The existing vibration isolator often cannot adjust the damping in real time and effectively according to these different intensity and frequency vibration conditions, so it cannot well meet the vibration isolation requirements.

[0004] In the field of magneto-rheological damping, magneto-rheological materials have attracted widespread attention due to their unique properties. As a new type of smart material, magneto-rheological elastomer can quickly and reversibly change its damping and other mechanical properties under the action of an external magnetic field. However, there is no perfect design scheme for applying magneto-rheological elastomer to elevator vibration isolation. The existing related technologies may have problems such as complex structure, inability to accurately sense vibration pressure, and inability to effectively ensure the uniformity of the magnetic field acting on the elastomer, which cannot fully utilize the advantages of magneto-rheological elastomer in elevator vibration isolation, and cannot well achieve effective isolation and buffering of vibration during elevator operation, affecting the safe and stable operation of the elevator and the ride experience of passengers.

[0005] The permanent magnet type magneto-rheological elastomer vibration isolator with patent number CN201822032697.7 includes a magnetic isolation cylinder, upper and lower cylinder cover seats, a magnetic conducting rod, and a magneto-rheological elastomer, etc. The magnetic sensing mechanism is composed of a magnetic sensing ring alternately composed of permanent magnet blocks and magnetic isolation blocks. Although it can achieve efficient vibration isolation through the magnetic sensing mechanism adjustment, it has problems such as complex structure, high manufacturing and maintenance cost, and poor flexibility of magnetic field adjustment.

[0006] The eddy current negative stiffness magneto-rheological elastomer vibration isolator with patent number CN202310713029.3 relates to a complex structure vibration isolator containing an eddy current damping structure and a negative stiffness magneto-rheological elastomer structure. However, it has defects such as stability affected by long-term relative motion of the eddy current structure, and complex overall system, low reliability, and many fault points.

[0007] Patent No. CN201720502536.3 based on the automobile seat vibration isolator of magnetorheological fluid, this is a vibration isolator for automobile seat, using magnetorheological fluid, but the magnetorheological fluid sealing is easy to be affected by vibration and appear wear and leakage problem, and the response speed is insufficient when the vibration changes fast in the driving of the automobile.

[0008] In summary, the existing patents have many shortcomings. Some traditional vibration isolators cannot effectively adjust the damping according to the actual vibration during elevator operation, such as vibration isolators based on hydraulic or spring principles, which have poor buffering effect when dealing with complex and variable vibration impact. Some magnetorheological related vibration isolators have problems such as complex structure, uneven magnetic field effect, and delayed response to vibration. Therefore, it is necessary to develop a new type of elevator vibration isolator based on magnetorheological elastomer. SUMMARY

[0009] The present application aims to provide a kind of elevator vibration isolator based on magnetorheological elastomer, by optimizing structure, utilize pressure sensor to sense vibration pressure, trigger excitation coil changes the damping of magnetorheological elastomer, realize efficient vibration isolation, and simple structure, small volume, low energy consumption, large carrying capacity.

[0010] The technical solution for achieving the purpose of the present application is:

[0011] A kind of elevator vibration isolator based on magnetorheological elastomer, including magnetorheological elastomer, pressure sensor is installed in the middle of the magnetorheological elastomer, the pressure sensor is surrounded by excitation coil, the upper and lower sides of pressure sensor are respectively equipped with upper end cap and lower end cap, the upper end cap and the top of magnetorheological elastomer, the lower end cap and the bottom of magnetorheological elastomer are all equipped with spring, the upper end cap, lower end cap and spring are magnetically conductive material;The damping of the magnetorheological elastomer changes under the action of magnetic field, and the damping increases when the magnetic field effect increases, wherein the magnetic field is generated by excitation coil according to the pressure signal transmitted by pressure sensor, the size of pressure signal and the size of triggered current are linearly related, that is, the greater the pressure, the greater the current, the stronger the magnetic field generated.

[0012] Preferably, the magnetorheological elastomer is a cylinder with a hollow cavity inside, and two annular grooves are provided on the magnetorheological elastomer to divide it into three parts: a first section, a middle section and a tail section, and the pressure sensor is installed in the middle section.

[0013] Preferably, the length ratio of the first section, the middle section and the tail section is 3:2:3. The magnetorheological elastomer is in a three-section cylindrical shape, which has a suitable length, length ratio of the first and last sections and the middle section, and size adaptation of the outer diameter and the inner diameter, to meet the comprehensive needs of structural stability, magnetic field effect and buffering performance in the application scenario of elevator vibration isolation.

[0014] Preferably, the magneto-rheological elastomer has a total length of 100 mm, an outer diameter of 50 mm, and an inner diameter of 20 cm.

[0015] Preferably, the spring has an elastic coefficient in the range of 10 N / mm to 30 N / mm. The elastic coefficient of the spring is carefully selected to have sufficient elasticity to buffer vibration and accurately transmit the vibration pressure sensed by the pressure sensor.

[0016] Preferably, the connecting surfaces of the upper end cover, the lower end cover, and the magneto-rheological elastomer are connected by H7 / g6 tolerance fitting, and are press-fitted by an assembly clamp. By the connecting mode, the fitting tolerance of the end cover, the spring, and the magneto-rheological elastomer is small, which can effectively prevent loosening or displacement between components during vibration.

[0017] Preferably, the upper end cover and the lower end cover are provided with magnetic flanges inside, and together with the spring form a closed magnetic circuit. The internal magnetic channel of the upper end cover is optimized by the magnetic flange to reduce magnetic field energy loss and magnetic field leakage, and the spring is subjected to special heat treatment process to ensure the consistency of elastic stability and magnetic permeability.

[0018] Preferably, the upper end cover, the lower end cover, and the spring are made of 45# steel magnetic material.

[0019] Preferably, the spring is subjected to quenching and tempering heat treatment, that is, quenched at 850°C and then tempered at 560°C.

[0020] Preferably, the pressure sensor is connected to the upper end cover and the lower end cover by a ball joint formed by a ball head and a ball bowl, so that when the vibration isolator is pressed, the pressure sensor and the excitation coil are always located inside the magneto-rheological elastomer.

[0021] The working principle of the elevator vibration isolator is as follows: when the elevator car moves downward under excessive weight, the magneto-rheological elastomer and the spring are compressed, the spring presses the pressure sensor, the pressure sensor makes the excitation coil generate a magnetic field to increase the damping of the magneto-rheological elastomer, and the greater the force on the car, the stronger the magnetic field, and the greater the damping. The whole process responds quickly from pressure generation, transmission to magnetic field generation and damping change.

[0022] Compared with the prior art, the present application has the following advantages: first, the structure is simple, the number of complex components is reduced, and the manufacturing and maintenance costs are reduced; second, the volume is small, which is convenient for installation in the limited space of the elevator; third, the energy consumption is low, which meets the energy saving demand and reduces the operating cost; fourth, the carrying capacity is large, which can adapt to the elevator operation under different load conditions, guarantee the vibration isolation effect, and improve the riding comfort. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The figure is an assembly drawing of the elevator vibration isolator of the present application.

[0024] Figure 2 A schematic diagram of a magneto-rheological elastomer.

[0025] Figure 3 A three-dimensional schematic diagram of the elevator vibration isolator.

[0026] Figure 4 A schematic diagram of the inner sensor and electromagnetic coil. DETAILED DESCRIPTION

[0027] The application will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0028] As shown in Figure 1 , the application provides an elevator vibration isolator based on a magneto-rheological elastomer, which comprises a magneto-rheological elastomer 1; a pressure sensor 2 arranged in the middle of the inside of the magneto-rheological elastomer; an excitation coil 3 arranged at the outer circle of the pressure sensor 2; an upper end cover 4 arranged at the upper side of the pressure sensor; a lower end cover 5 arranged at the lower side of the pressure sensor; a first spring 6 arranged at the upper side of the upper end cover and connected thereto; and a second spring 7 arranged at the lower side of the lower end cover and connected thereto.

[0029] As shown in Figure 2 , the magneto-rheological elastomer is composed of three sections and has a cylindrical shape as a whole. The magneto-rheological elastomer has a three-section cylindrical shape, which has a suitable length, a proportionally coordinated length of the first and last sections and the middle section, and a size of the outer diameter and the inner diameter that are suitable for meeting the comprehensive needs for structural stability, magnetic field effect, and buffering performance in the application scenario of elevator vibration isolation. At the same time, the distribution and arrangement of the magnetic particles in the inside of the magneto-rheological elastomer can better interact with the magnetic field at this size, and the ferromagnetic particle content distribution in the preparation of the magneto-rheological elastomer is greater in the middle than at both ends, which ensures that the magneto-rheological elastomer can produce a certain deformation and provide damping, thereby providing a good foundation for the subsequent precise adjustment of damping.

[0030] The middle section is the core area of the magnetic field effect, and the first and last sections mainly play the roles of support and initial buffering. The ratio of the first section, the middle section, and the last section is 3:2:3, and the total length of the elastomer is 100 mm, the outer diameter is 50 mm, and the inner diameter is 20 cm.

[0031] As shown in Figure 3 and Figure 4As shown, the pressure sensor 2 is provided with a first spring 6, the first spring 6 is connected to the upper end cover 4 and flush with the upper end surface of the magnetorheological elastomer; the pressure sensor 2 is provided with a second spring 7 below, the second spring 7 is connected to the lower end cover 5 and flush with the lower end surface of the magnetorheological elastomer, the connection of the first spring 6 and the second spring 7 with the upper end cover 4 and the lower end cover 5 ensures that the pressure sensor 2 and the excitation coil 3 are always located in the middle part inside the magnetorheological elastomer even under pressure, which ensures that the excitation coil 3 generates a uniform magnetic field when energized to act on the upper and lower parts of the magnetorheological elastomer.

[0032] The pressure sensor is a high-precision sensing element that can accurately sense slight pressure changes. Ensure that the connection between the two is stable and the signal transmission is accurate when the vibration isolator is subjected to complex vibration and pressure. The spring coefficient should have enough elasticity to buffer vibration, but should not be too soft or rigid to affect the accurate transmission of the pressure sensor to the vibration pressure. Based on the load of the elevator car and the expected vibration displacement, the spring coefficient is preferably in the range of 10 N / mm ~ 30 N / mm. To ensure that while effectively buffering vibration, it can accurately and linearly transmit pressure to the pressure sensor.

[0033] In addition to providing support and guidance for the spring, the upper and lower end covers have a very small tolerance with the spring and magnetorheological elastomer. The mating surface of the upper and lower end covers and the magnetorheological elastomer uses a H7 / g6 tolerance fit, and is pressed by a special assembly clamp, effectively preventing loosening or displacement between components during vibration. Can effectively prevent loosening or displacement between components during vibration, thereby ensuring that the pressure sensor and the excitation coil are always in the middle of the magnetorheological elastomer when the vibration isolator is under pressure. This design is crucial to ensure that the magnetic field acts uniformly on the upper and lower parts of the magnetorheological elastomer, effectively avoiding the problem of inaccurate damping adjustment caused by uneven magnetic field.

[0034] The end cover and spring are made of magnetic conductive material 45# steel. The 45# steel not only has good magnetic conductive performance, but also has high mechanical strength and good toughness. In the manufacturing process, the size precision and surface quality of the end cover and spring are ensured through fine machining process. For the end cover, the internal magnetic conductive channel is optimized in design. The upper end cover and the lower end cover are provided with annular magnetic conductive flanges on the end faces opposite to the magnetic conductive spring. The flanges extend into the end part of the magnetic conductive spring and form a closed magnetic circuit with the magnetic conductive spring. The magnetic circuit is optimized through finite element analysis software, so that the magnetic field generated by the excitation coil can be concentrated to pass through the working section of the magneto-rheological elastomer, significantly reducing the magnetic field leakage and energy loss. The magnetic field generated by the excitation coil can pass through the working gap in the most ideal path, reducing the magnetic field energy loss and magnetic field leakage. The spring is manufactured through special heat treatment process, which ensures the elastic stability and consistency of the magnetic conductive performance in the long-term use. The application of the 45# steel material and the fine manufacturing process can make the magnetic field generated by the excitation coil pass through the working gap to the maximum extent, reduce the magnetic field energy loss, enhance the effect on the magneto-rheological elastomer, and ensure the effectiveness of the damping adjustment. The 45# steel spring is quenched at 850°C and then tempered at 560°C to obtain a tempered sorbite structure, so as to ensure high fatigue strength, stable elastic performance and consistent magnetic conductivity.

[0035] In the present example, the damping of the magneto-rheological elastomer changes under the action of the magnetic field, and the damping of the magneto-rheological elastomer increases with the increase of the magnetic field. The upper end cover 4, the lower end cover 5, the first spring 6 and the second spring 7 are all made of magnetic conductive material 45# steel. The selection of the magnetic conductive material will be conducive to the magnetic field generated by the excitation coil 3 to pass through the working gap to the maximum extent.

[0036] The connection mode of the pressure sensor and the upper and lower end covers can ensure that the pressure sensor and the excitation coil are always located in the middle of the magnetorheological elastomer when the vibration isolator is under pressure, and the pressure sensor and the end cover are connected through a high-strength and low-friction ball head-ball bowl connection point to ensure stable connection and accurate signal transmission. A ball head is processed in the center of each of the upper and lower force surfaces of the pressure sensor, and a ball bowl seat is embedded in the end of the upper and lower end covers corresponding to the ball head. The ball head is pressed into the ball bowl to form a micro-rotatable connection pair. This structure can automatically adapt to the slight deflection of the end cover, but always concentrates the force point on the central axis of the pressure sensor. In order to realize high-strength and low-friction connection, the upper and lower surfaces of the pressure sensor (2) are each provided with a hard alloy ball head, and the lower ends of the upper and lower end covers are each pressed with an alloy steel ball bowl seat. The ball head and the ball bowl seat form a ball hinge connection pair, the contact surfaces of which are quenched and ground and filled with lubricating grease. This structure can withstand high impact load, and can also adapt to the deformation of the end cover side spring through the micro rotation of the ball head to reduce the friction resistance to the minimum, thereby ensuring the accuracy and linearity of pressure transmission, and finally ensuring that the pressure sensor (2) and the excitation coil (3) around it are always stably located in the middle of the magnetorheological elastomer (1) when the vibration isolator is under pressure.

[0037] The specific working principle is as follows:

[0038] When the elevator is running, such as going up and the car is overweight, the downward force on the car is transmitted to the vibration isolator through the car bottom. At this time, the magnetorheological elastomer first bears the pressure and starts to deform, and the magnetic particles in its interior start to be squeezed and displaced. At the same time, the spring is also compressed, and the compression process of the spring is a gradual energy storage process, and the elastic potential energy stored is proportional to the pressure. As the car continues to move down, the compression of the spring on the pressure sensor gradually increases. The pressure sensor converts the pressure it senses into an electrical signal based on high-precision sensing principles such as piezoresistive effect or capacitance change. When the pressure reaches a certain threshold, the electrical signal triggers the excitation coil to be energized.

[0039] After the excitation coil is electrified, a magnetic field is generated according to the electromagnetic induction law. The direction and strength of the magnetic field are related to the size and direction of the current passing through the coil. In the present application, the size of the pressure signal delivered by the pressure sensor is in linear relationship with the size of the triggered current, that is, the greater the pressure, the greater the current, and the stronger the generated magnetic field. This magnetic field will quickly penetrate the magneto-rheological elastomer. The magnetic particles in the magneto-rheological elastomer quickly rearrange and polarize under the action of the magnetic field, causing changes in its internal microstructure, which in turn leads to changes in its macroscopic damping characteristics. Moreover, this change is real-time and reversible. As the force on the car further increases, the signal delivered by the pressure sensor continues to increase, and the strength of the magnetic field generated by the excitation coil also continues to increase, and the damping of the magneto-rheological elastomer under the action of the magnetic field also increases, thereby effectively absorbing and buffering the vibration energy of the car. In the whole process, from the generation and transmission of pressure to the generation of magnetic field and the change of damping, each link is closely coordinated and responds quickly, ensuring that the vibration isolator can play an excellent vibration isolation effect under different vibration intensities.

[0040] Although preferred embodiments of the application have been described, those skilled in the art will be able to make additional changes and modifications to these embodiments once they have been given the basic inventive concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0041] Obviously, those skilled in the art can make various modifications and variations to the embodiments of the present application without departing from the spirit and scope of the embodiments of the present application. Thus, if these modifications and variations of the embodiments of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A magnetorheological elastomer based elevator isolator, characterized by, The magnetorheological elastomer is internally provided with a pressure sensor, the pressure sensor is surrounded by an excitation coil, the upper and lower sides of the pressure sensor are respectively provided with an upper end cover and a lower end cover, springs are arranged between the upper end cover and the top of the magnetorheological elastomer and between the lower end cover and the bottom of the magnetorheological elastomer, and the upper end cover, the lower end cover and the springs are magnetically conductive materials; the magnetorheological elastomer changes in damping under the action of a magnetic field, and the damping increases when the action of the magnetic field is enhanced, wherein the magnetic field is generated by the excitation coil according to the pressure signal transmitted by the pressure sensor.

2. A magnetorheological elastomer based elevator isolator according to claim 1, characterized in that, The magnetorheological elastomer is a cylinder and has a hollow cavity inside, the magnetorheological elastomer is provided with two annular grooves, and the magnetorheological elastomer is divided into three parts, i.e., a first section, a middle section and a tail section, and the pressure sensor is arranged in the middle section.

3. A magnetorheological elastomer based elevator isolator according to claim 2, characterized in that, The length ratio of the first section, the middle section and the tail section is 3:2:

3.

4. A magnetorheological elastomer based elevator isolator according to claim 3, characterized in that, The total length of the magnetorheological elastomer is 100 mm, the outer diameter is 50 mm, and the inner diameter is 20 cm.

5. The magnetorheological elastomer based elevator isolator according to claim 1, wherein, The elastic coefficient of the spring ranges from 10 N / mm to 30 N / mm.

6. A magnetorheological elastomer based elevator isolator according to claim 1, characterized in that, The connecting surfaces of the upper end cover, the lower end cover and the magnetorheological elastomer are connected in a H7 / g6 level tolerance fit, and are press-fitted through an assembly clamp.

7. The magnetorheological elastomer based elevator isolator according to claim 1, wherein, The upper end cover and the lower end cover are provided with annular magnetically conductive flanges on the end surfaces close to the springs, the flanges extend into the end portions of the magnetically conductive springs, and the magnetically conductive springs and the magnetically conductive flanges jointly form a closed magnetic circuit.

8. The magnetorheological elastomer based elevator isolator according to claim 1, wherein, The upper end cover, the lower end cover and the spring are 45# steel magnetically conductive materials.

9. A magnetorheological elastomer based elevator isolator according to claim 8, characterized in that, The spring is subjected to quenching and tempering heat treatment, i.e., quenching at 850°C and then high-temperature tempering at 560°C.

10. The magnetorheological elastomer based elevator isolator according to claim 1, wherein, The pressure sensor is connected to the upper end cover and the lower end cover through a ball joint formed by a ball head and a ball bowl.

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