A medium-low speed maglev train and a braking device thereof

Abstract

The application discloses a medium-low speed maglev train and a braking device thereof, which comprises an eddy current braking device installed on the medium-low speed maglev train, and an elastic connecting piece is arranged between the eddy current braking device and the medium-low speed maglev train, wherein the elastic connecting piece has a tendency of making the eddy current braking device away from a guide rail of the medium-low speed maglev train; and a brake plate is arranged on one side of the eddy current braking device close to the guide rail. Compared with the prior art, the application avoids the suspension control instability caused by the large braking impact, and guarantees the running stability and safety of the vehicle. Furthermore, the brake plate is combined with the eddy current braking device, so that the installation space is saved, and the automatic switching of the eddy current braking and the mechanical braking can be realized through the setting of the appropriate pre-tightening spring force, and the complexity of the system is reduced. In addition, the mechanical braking device and the eddy current braking device act on the existing one maglev track, and a new track is not needed.

Description

Technical Field

[0001] This invention relates to the field of medium- and low-speed maglev train technology, specifically to a medium- and low-speed maglev train and its braking device. Background Technology

[0002] Existing medium- and low-speed maglev trains use mechanical brake calipers for braking. For example... Figure 1 As shown, the mechanical brake caliper 7 is vertically mounted on the levitation electromagnet 2. During mechanical braking, the hydraulically driven mechanical brake caliper 7 causes the brake pad 8 to contact the guide rail 1. The longitudinal braking force generated by the friction between the brake pad 8 and the guide rail 1 is almost entirely transmitted to the lateral skid device via the longitudinal tie rod. Due to the rigid connection between the lateral skid and the electromagnet plate, the braking force is directly transmitted to the electromagnet plate. During emergency braking at higher speeds, the braking impact is significant, which can easily cause levitation control instability, resulting in rail impact and affecting the vehicle's operational stability and safety.

[0003] Eddy current braking devices utilize the Lorentz force generated by electromagnetic eddy currents in a magnetic field, with the direction opposite to the object's motion, to generate braking force. They offer advantages such as frictionless operation at high speeds, noiseless operation, small size, and high braking force. Chinese invention application CN115723582A discloses a high-temperature superconducting maglev train structure and its control method. This invention employs a combination of high-speed eddy current braking and low-speed mechanical braking to achieve braking of the maglev train, improving the safety of high-speed maglev train braking. Its disadvantages are: the eddy current braking device and the mechanical braking device are separately and independently installed, occupying a large installation space and requiring software to switch between eddy current braking and mechanical braking, increasing system complexity. Secondly, the eddy current braking device and mechanical braking device on this high-speed maglev train are respectively set up for two tracks, making it unsuitable for medium- and low-speed maglev trains with only one track. Summary of the Invention

[0004] This application provides a medium-low speed maglev train and its braking device to solve the technical problem that the mechanical braking device of existing medium-low speed maglev trains has a large braking impact during emergency braking at high speeds, which can easily cause suspension control instability and affect the stability and safety of vehicle operation.

[0005] To achieve the above objectives, this application adopts the following technical solution.

[0006] On the one hand, a braking device for a medium- and low-speed maglev train is provided, including an eddy current braking device installed on the medium- and low-speed maglev train, wherein an elastic connector is provided between the eddy current braking device and the medium- and low-speed maglev train, and the elastic connector has a tendency to move the eddy current braking device away from the guide rail of the medium- and low-speed maglev train; a brake plate is provided on the side of the eddy current braking device near the guide rail.

[0007] When a train undergoes emergency braking at high speed, eddy current braking is employed. As the vehicle speed decreases, the characteristics of eddy current braking cause the attraction between the braking magnetic poles and the guide rail to gradually increase. When this attraction exceeds the preload spring force set by the elastic connector, the eddy current braking device begins to move towards the guide rail, reducing the gap between the device and the rail, further increasing the attraction until the brake plate contacts the rail, generating frictional braking force. Therefore, using eddy current braking for emergency braking at high speeds avoids suspension control instability caused by large braking impacts, ensuring vehicle stability and safety. Secondly, by combining the brake plate with the eddy current braking device, this invention not only saves installation space but also enables automatic switching between eddy current braking and mechanical braking, reducing system complexity. Thirdly, by setting different preload spring forces, the contact timing between the brake plate and the guide rail can be adjusted to trigger the mechanical braking at the corresponding vehicle speed, thus meeting different braking requirements. Finally, the mechanical braking device and the eddy current braking device operate on an existing maglev track, eliminating the need for additional tracks.

[0008] In some embodiments, the eddy current braking device includes a magnetic yoke and a braking magnetic pole unit disposed between the magnetic yoke and the braking plate; the braking magnetic pole unit includes a first iron core and a braking magnetic pole coil wound on the first iron core; there are multiple braking magnetic pole units, which are arranged along the length direction of the guide rail, and the polarities of the multiple braking magnetic pole units are arranged in an alternating SN pattern.

[0009] In some embodiments, a second iron core is provided on the outer side of each of the two outermost braking magnetic pole units. The added second iron core incorporates the entire magnetic flux generated by the braking magnetic pole units at the ends into the magnetic circuit, effectively improving the magnetic field utilization rate and increasing the eddy current braking force.

[0010] To accommodate lightweight requirements, in some embodiments, the thickness of the second core is half that of the first core.

[0011] To increase the eddy current braking force, in some embodiments, the lower surface of the guide rail is also provided with an aluminum induction plate.

[0012] In some embodiments, the levitation electromagnet of the medium-low speed maglev train is located below the guide rail, and the eddy current braking device is located between the guide rail and the levitation electromagnet; the bottom of the eddy current braking device is connected to the upper surface of the levitation electromagnet through the elastic connector; and the brake plate is located at the top of the eddy current braking device.

[0013] The present invention provides a specific structure of an elastic connector. In some embodiments, the elastic connector includes a first support, a second support, and a compression spring.

[0014] The first bracket is rectangular, with its upper part fixedly connected to the bottom of the eddy current braking device and its lower part having a notch;

[0015] The second support includes a column and a crossbeam. The upper end of the column is fixedly connected to the middle of the crossbeam, and the lower end of the column passes through the notch and is fixedly connected to the upper surface of the levitation electromagnet. The two ends of the crossbeam are respectively fixedly connected to the lower part of the first support by a compression spring.

[0016] In some embodiments, a shim is further provided between the first support and the upper surface of the levitation electromagnet. This allows the preload force of the compression spring to be adjusted using shims of different thicknesses.

[0017] In some embodiments, the levitation electromagnet of the medium-low speed maglev train is located below the guide rail, and the end of the guide rail is provided with outer rail teeth; the side of the levitation electromagnet is provided with a brake caliper, the lower end of the brake caliper is movably connected to the levitation electromagnet, the middle part is fixedly connected to the levitation electromagnet through a compression spring, and the upper end is equipped with the eddy current braking device; the brake plate is located on the side of the eddy current braking device near the outer rail teeth.

[0018] On the other hand, a medium-low speed maglev train is provided, which is equipped with the aforementioned medium-low speed maglev train braking device.

[0019] This application has at least the following technical effects or advantages:

[0020] 1. During emergency braking at high speeds, an eddy current braking device is used to perform eddy current braking, which avoids suspension control instability caused by large braking impact, thus ensuring vehicle operation stability and safety.

[0021] 2. By combining the brake plate with the eddy current braking device, this invention not only saves installation space, but also enables automatic switching between eddy current braking and mechanical braking by setting an appropriate preload spring force, thus reducing the complexity of the system.

[0022] 3. The mechanical braking device and the eddy current braking device work on an existing maglev track, so there is no need to add a new track.

[0023] 4. By setting different preload spring forces, the vehicle speed corresponding to triggering mechanical braking can be adjusted, thereby meeting different braking requirements.

[0024] 5. By adding a second iron core, the magnetic field utilization rate is effectively improved, thereby increasing the eddy current braking force.

[0025] 6. By adding an aluminum induction plate, the eddy current braking force is further increased. Attached Figure Description

[0026] Figure 1 This is a front view of the mechanical braking device used in existing medium- and low-speed maglev trains.

[0027] Figure 2 This is a perspective view of a braking device for a medium- and low-speed maglev train according to an embodiment of this application;

[0028] Figure 3 This is a front view of an eddy current braking device according to an embodiment of this application;

[0029] Figure 4 This is a side view of an eddy current braking device according to an embodiment of this application;

[0030] Figure 5 This is a side view of an eddy current braking device according to an embodiment of this application;

[0031] Figure 6 This is a schematic diagram of the structure of the elastic connector in one embodiment of this application;

[0032] Figure 7 This is a schematic diagram of the guide rail structure in one embodiment of this application.

[0033] Figure 8 This is a front view of an eddy current braking device according to an embodiment of this application. Detailed Implementation

[0034] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0035] Example 1

[0036] See Figures 2-7 A braking device for a medium-low speed maglev train includes an eddy current braking device 3 disposed between a guide rail 1 and a levitation electromagnet 2 of the medium-low speed maglev train. The bottom of the eddy current braking device 3 is connected to the upper surface of the levitation electromagnet 2 via an elastic connector 4. A brake plate 5 is provided on the top of the eddy current braking device 3, and the brake plate 5 has a gap with the lower surface of the guide rail.

[0037] The levitation electromagnet 2 includes an inner pole plate, an outer pole plate, an iron core, and a coil. The inner and outer pole plates are equipped with elastic connecting parts 4 for mounting. The brake plate 5 must be made of a wear-resistant, non-magnetic metal material, and its hardness must be lower than that of the guide rail material to prevent scratching the guide rail during friction braking.

[0038] like Figure 4 and Figure 5As shown, the eddy current braking device 3 includes a magnetic yoke 31 and a braking magnetic pole unit disposed between the magnetic yoke 31 and the braking plate 5. The braking magnetic pole unit includes a first iron core 32 and a braking magnetic pole coil 33 wound on the first iron core 32. Multiple braking magnetic pole units are provided, arranged along the length of the guide rail, and the polarities of the multiple braking magnetic pole units are arranged in an alternating SN pattern.

[0039] The eddy current braking device 3 is installed using the existing hydraulic mechanical brake caliper mounting space and is connected to the inner and outer pole plates of the levitation electromagnet 2 via the elastic connector 4. The eddy current braking device 3 is located below the guide rail 1, with the brake plate 5 facing the lower surface of the guide rail 1. The gap between the electromagnet pole plate and the lower surface of the guide rail teeth is δ. When the eddy current braking device 3 is not working, the gap between the upper surface of the brake plate 5 and the middle lower surface of the guide rail 1 is ε. To ensure that the brake plate 5 does not contact the guide rail 1 under normal driving conditions, the following relationship should hold: δ < ε.

[0040] The polarities of the braking magnetic pole units are arranged alternately in SN or NS patterns, with a quantity of 2n (n = 1, 2, 3...). The specific number can be determined based on the actual braking force requirements of the vehicle and the available installation space. The number of the first iron core 32 is also 2n. For example... Figure 3 As shown, there should be a sufficient gap l in the transverse direction of the magnetic poles to prevent the braking magnetic poles from colliding and interfering with the sides of the guide rails when the electromagnet is in a transverse movement condition, thus preventing damage to the magnetic poles.

[0041] like Figure 5 As shown, in a preferred embodiment, a second iron core 34 is provided on the outer side of each of the two outermost braking magnetic pole units. The thickness of the second iron core 34 is half that of the first iron core 33.

[0042] like Figure 6As shown, the elastic connector 4 includes a first bracket 41, a second bracket 42, and a compression spring 43. The first bracket 41 is rectangular, with its upper part fixedly connected to the bottom of the eddy current braking device 3 and its lower part having a notch. The second bracket 42 includes a column and a crossbeam. The upper end of the column is fixedly connected to the middle of the crossbeam, and the lower end of the column passes through the notch and is fixedly connected to the upper surface of the levitation electromagnet 2. Both ends of the crossbeam are fixedly connected to the lower part of the first bracket 41 by a compression spring 43. Specifically, both ends of the crossbeam are fixedly connected to the upper end of the compression spring 43 by a first connector 441, and the lower end of the compression spring 43 is fixedly connected to the lower part of the first bracket 41. A gasket 45 is also provided between the first bracket 41 and the upper surface of the levitation electromagnet 2. The upper surface of the gasket 45 abuts against the lower part of the first bracket 41, and its lower surface is fixedly connected to the upper part of the second connector 442. The lower part of the second connector 442 is fixedly connected to the levitation electromagnet 2.

[0043] The guide rail, while providing the excitation circuit for the magnetic field generated by the levitation electromagnet, also acts as the target of the linear eddy current braking device, generating vortex-shaped induced eddy currents. These eddy currents interact with the braking magnetic poles to form an eddy current braking force opposite to the vehicle's direction of travel, as well as a vertical electromagnet attraction force. To increase the eddy current braking force, as a preferred solution, such as... Figure 7 As shown, the lower surface of the guide rail 1 is also provided with an aluminum sensing plate 6.

[0044] Working principle:

[0045] During the pre-tightening assembly of the elastic connector 4, the second bracket 42 pre-compresses the compression spring 43 downwards. The gap in the compression stroke of the compression spring 43 is filled by the shim 45. At this time, the downward pressure of the second bracket 42 is equal to the pressure between the shim 45 and the first bracket 41, which is the pre-tightening spring force. When the eddy current braking device 3 is energized, it generates a vertical attraction and a longitudinal braking force. The attraction reduces the pressure between the shim 45 and the first bracket 41. As the vehicle speed decreases, the characteristics of eddy current braking cause the vertical attraction between the brake magnetic pole and the guide rail 1 to gradually increase. When it exceeds the set pre-tightening spring force, the compression spring 43 begins to compress, and the shim 45 separates from the first bracket 41. Specifically, the brake magnetic pole as a whole begins to move vertically upwards, the gap between the magnetic pole and the guide rail decreases, and the attraction further increases until the brake plate 5 contacts the lower surface of the guide rail 1, thereby generating a frictional braking force. Therefore, the vertical movement of the eddy current braking electromagnet can be limited by setting an appropriate preload spring force, avoiding direct contact between the eddy current braking device and the guide rail at high speeds, which would cause excessive braking impact. In this embodiment, the preload spring force is configured such that when the vehicle speed decreases to approximately 60km / h to 80km / h, the brake plate 5 contacts the lower middle surface of the guide rail 1 for mechanical braking.

[0046] Example 2

[0047] This embodiment is basically the same as Embodiment 1, except that the installation position of the eddy current braking device is different. In this embodiment, the installation position of the eddy current braking device is the same as that of the brake pads in existing mechanical braking devices. Figure 8 As shown, the guide rail 1 has an outer rail tooth 11 at its end, and the levitation electromagnet 2 has a brake caliper 7 on its side. The lower end of the brake caliper 7 is movably connected to the levitation electromagnet 2, and the middle part is fixedly connected to the levitation electromagnet 2 through an elastic connector 4 (in this embodiment, the elastic connector 4 is a compression spring). The upper end is equipped with the eddy current braking device 3, and the brake plate 5 is located on the side of the eddy current braking device 3 near the outer rail tooth 11. The eddy current braking device 3 includes a magnetic yoke 31 and a braking magnetic pole unit disposed between the magnetic yoke 31 and the brake plate 5. The braking magnetic pole unit includes a first iron core 32 and a braking magnetic pole coil 33 wound on the first iron core 32. There are multiple braking magnetic pole units, which are arranged along the length of the guide rail. The polarities of the multiple braking magnetic pole units are arranged alternately in SN or NS, and the number is 2n (n = 1, 2, 3...). The specific number can be determined according to the actual braking force requirements of the vehicle and the size of the installation space. The number of the first iron core 32 is also 2n.

[0048] like Figure 5 As shown, in a preferred embodiment, a second iron core 34 is provided on the outer side of each of the two outermost braking magnetic pole units. The thickness of the second iron core 34 is half that of the first iron core 33.

[0049] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0050] Similarly, it should be understood that, in order to streamline this disclosure and aid in understanding one or more of the various aspects of the invention, in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof. However, this method of disclosure should not be interpreted as reflecting an intention that the claimed invention requires more features than expressly recited in each claim. Rather, as reflected in the claims, inventive aspects lie in fewer than all features of a single foregoing disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of the invention.

[0051] Those skilled in the art will understand that the modules, units, or groups of devices in the examples disclosed herein can be arranged in the device as described in this embodiment, or alternatively, can be located in one or more devices different from the device in this example. The modules in the foregoing examples can be combined into a single module or, in addition, can be divided into multiple sub-modules.

[0052] Those skilled in the art will understand that modules in the device of the embodiments can be adaptively changed and placed in one or more devices different from that embodiment. Modules, units, or groups in the embodiments can be combined into a single module, unit, or group, and further, they can be divided into multiple sub-modules, sub-units, or sub-groups. Except where at least some of such features and / or processes or units are mutually exclusive, any combination can be used to combine all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or units of any method or device so disclosed. Unless expressly stated otherwise, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature that serves the same, equivalent, or similar purpose.

[0053] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features but not others included in other embodiments, combinations of features from different embodiments are intended to be within the scope of the invention and form different embodiments. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0054] As used herein, unless otherwise specified, the use of ordinal numbers such as “first,” “second,” “third,” etc., to describe ordinary objects merely indicates different instances of similar objects and is not intended to imply that the objects being described must have a given order in time, space, ordering, or any other manner.

[0055] Although the invention has been described with reference to a limited number of embodiments, those skilled in the art will understand from the foregoing description that other embodiments are conceivable within the scope of the invention described herein. Furthermore, it should be noted that the language used in this specification has been chosen primarily for readability and instructional purposes, and not for the purpose of interpreting or limiting the subject matter of the invention. Therefore, many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the appended claims. The disclosure of the invention is illustrative and not restrictive, and the scope of the invention is defined by the appended claims.

[0056] Finally, it should be noted that this invention does not explain in detail the common knowledge recognized by those skilled in the art. The above description is only a specific embodiment of this invention and is not intended to limit this invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the protection scope of this invention.

Claims

1. A braking device for medium- and low-speed maglev trains, characterized in that, The system includes a levitation electromagnet and an eddy current braking device installed on a medium-low speed maglev train. The levitation electromagnet is located below the guide rail of the medium-low speed maglev train, and the eddy current braking device is located between the guide rail and the levitation electromagnet. The bottom of the eddy current braking device is connected to the upper surface of the levitation electromagnet by an elastic connector, which tends to move the eddy current braking device away from the guide rail. A braking plate is provided on the top of the eddy current braking device. The guide rail is an F-type guide rail.

2. The braking device for medium- and low-speed maglev trains according to claim 1, characterized in that: The eddy current braking device includes a magnetic yoke and a braking magnetic pole unit disposed between the magnetic yoke and the braking plate; the braking magnetic pole unit includes a first iron core and a braking magnetic pole coil wound on the first iron core; there are multiple braking magnetic pole units, which are arranged along the length of the guide rail, and the polarities of the multiple braking magnetic pole units are arranged in an alternating SN pattern.

3. The braking device for medium- and low-speed maglev trains according to claim 2, characterized in that: A second iron core is provided on the outer side of each of the two outermost braking magnetic pole units.

4. The braking device for medium- and low-speed maglev trains according to claim 3, characterized in that: The thickness of the second iron core is half that of the first iron core.

5. The braking device for medium- and low-speed maglev trains according to any one of claims 1-4, characterized in that: The elastic connector includes a first bracket, a second bracket, and a compression spring; The first bracket is rectangular, with its upper part fixedly connected to the bottom of the eddy current braking device and its lower part having a notch; The second support includes a column and a crossbeam. The upper end of the column is fixedly connected to the middle of the crossbeam, and the lower end of the column passes through the notch and is fixedly connected to the upper surface of the levitation electromagnet. The two ends of the crossbeam are respectively fixedly connected to the lower part of the first support by a compression spring.

6. The braking device for medium- and low-speed maglev trains according to claim 5, characterized in that: A gasket is also provided between the first support and the upper surface of the levitation electromagnet.

7. The braking device for medium- and low-speed maglev trains according to any one of claims 1-4, characterized in that: The lower surface of the guide rail is also provided with an aluminum induction plate.

8. A medium-low speed maglev train, characterized in that: The medium-low speed maglev train is equipped with a braking device as described in any one of claims 1-7.

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