A suspension gap sensor for medium and low speed maglev trains

Abstract

The present invention discloses a suspension gap sensor for medium and low speed maglev trains, wherein the shell comprises a first shell part and a second shell part which are arranged in an L shape, wherein the other end of the first shell part away from the second shell part is arranged as an arc-shaped annular wall; the control unit is fixedly installed in the second shell part; the probe unit comprises a gap measuring coil group, a probe circuit board and a coil skeleton which are fixed in the first shell part in sequence from top to bottom, wherein the other side of the coil skeleton away from the control unit is arranged as a first arc-shaped end matched with the arc-shaped annular wall, the probe circuit board is electrically connected to the control unit, and the end of the probe circuit board is arranged as a second arc-shaped end; the gap measuring coil group comprises a gap measuring coil I and a gap measuring coil II, wherein the gap measuring coil I is arranged as an annular structure, and the gap measuring coil II is a rectangular structure; an epoxy resin glue layer is filled in the first shell part, and with the above arrangement, there is no dead angle for glue injection, thereby reducing the risk of glue layer cracking caused by curing stress.

Description

Technical Field

[0001] The invention relates to the technical field of sensors, and in particular to a suspension gap sensor for medium and low speed maglev trains. Background Art

[0002] Existing gap sensors, such as a medium- and low-speed magnetic levitation gap sensor and a detection method thereof, are disclosed in a Chinese patent (authorization announcement number CN116358401B), in which the medium- and low-speed magnetic levitation gap sensor includes a main body, a control part, a probe part, a collection circuit board, a gap measurement coil group, and an accelerometer. The main body is L-shaped, including a control part and a probe part having a cavity and being perpendicular to each other. The collection circuit board is arranged in the cavity of the control part and is electrically connected to the probe part to collect and process the gap signal detected by the probe part.

[0003] In another medium and low speed suspension gap sensor, in order to support and protect the gap measurement coil group, a coil frame is generally set at the bottom of the gap measurement coil group to ensure the stability and reliability requirements of the measurement under the environment, temperature / humidity of the medium and low speed maglev train throughout the year and throughout the whole journey. Therefore, the existing gap sensor is sealed by filling epoxy resin glue. When filling glue, it is specifically filled at the bend of the L-shaped shell. Since the other end of the shell away from the filling side is set at a right angle, there is a dead corner for glue injection. The epoxy resin is not filled sufficiently at the dead corner, which will cause the glue layer to crack due to curing stress. In addition, if the problem of glue injection dead corner is solved by increasing the filling amount, it will cause the glue injection amount to be too large, resulting in an increase in the overall submission of the medium and low speed suspension gap sensor and an increase in weight, so it needs to be improved.

[0004] In addition, the existing medium and low speed suspension gap sensors still have the following bottleneck problems: 1. How to ensure the consistency of the probe coil parameters during the mass production process. The sources of consistency deviation are: one is the probe coil material itself, which is usually solved by screening probe coils that meet the performance requirements; the other is the process deviation caused by the assembly process, which can usually be weakened to a certain extent through debugging of the back-end circuit board, but this debugging is often accompanied by time and labor costs, and there is a certain degree of risk of debugging failure, which will lead to product scrapping. Therefore, the above solutions are not ideal. 2. The problem that the parameters of the coil are easily affected by temperature and change. When the temperature changes, the probe coil itself and the different materials in contact with it will deform due to differences in thermal expansion coefficients, generating thermal stress, which ultimately acts on the probe coil and causes parameter deviations. Summary of the invention

[0005] The purpose of the present invention is to provide a suspension gap sensor for medium and low speed maglev trains. The sensor detection probe part is designed in an arc shape. When epoxy resin is poured, the end portion has an arc-shaped smooth transition, which reduces stress concentration areas such as right angles, and there is no dead angle for glue injection, so that the epoxy resin can be fully filled, reducing the risk of cracking of the glue layer caused by curing stress. At this time, the epoxy resin glue layer can more easily form a thinner glue layer during pouring, while ensuring the insulation and protection strength, further reducing the amount of epoxy resin poured, thereby assisting in weight reduction.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions: A suspension gap sensor for medium and low speed maglev trains, comprising:

[0007] The housing comprises a first housing portion and a second housing portion arranged in an L shape, and the other end of the first housing portion away from the second housing portion is arranged as an arc-shaped annular wall;

[0008] A control unit, which is fixedly installed in the second housing portion;

[0009] The probe unit comprises a gap measuring coil group, a probe circuit board and a coil frame which are fixed in sequence in the first shell part from top to bottom, the coil frame is arranged as a first arc-shaped end matched with the arc-shaped ring wall on the other side away from the control unit, the probe circuit board is electrically connected to the control unit, and the probe circuit board is arranged as a second arc-shaped end relative to the other side of the control unit, the gap measuring coil group comprises a gap measuring coil I arranged laterally at intervals and at least one gap measuring coil II, the gap measuring coil I is arranged as a circular ring structure and its outer diameter is matched with the second arc-shaped end of the probe circuit board, the gap measuring coil II is a rectangular structure, and the first shell part is filled with an epoxy resin adhesive layer so that the probe unit is sealed and coated between the first shell part and the epoxy resin adhesive layer.

[0010] Furthermore, the probe circuit board is a flexible circuit board, and the gap measurement coil group is coated inside the flexible circuit board FPC in the form of copper.

[0011] Furthermore, the coil skeleton is made of PMI material, and the thermal expansion coefficients of the probe circuit board, the coil skeleton and the epoxy resin adhesive layer match each other.

[0012] Furthermore, the second arc-shaped end head matches the first arc-shaped end head, so that the second arc-shaped end head is adapted to the arc-shaped annular wall.

[0013] Furthermore, an accommodating space matching the shape of the probe circuit board is opened at the upper end of the coil skeleton, and the probe circuit board is at least partially accommodated in the accommodating space.

[0014] Furthermore, the gap measurement coil II is a square coil, and the side length of the gap measurement coil II is consistent with the width of the probe circuit board.

[0015] Furthermore, the coil skeleton and the probe circuit board are respectively provided with corresponding positioning holes. During assembly, the fasteners pass through the positioning holes of the coil skeleton and the probe circuit board and are fixedly connected to the first shell portion.

[0016] Furthermore, the gap measurement coil group and the probe circuit board are all in the accommodation space, and the end of the gap measurement coil group is in contact with the inner cavity wall of the accommodation space of the coil skeleton.

[0017] Furthermore, the second shell part is provided with a cavity with a side opening, the control unit includes at least one acquisition circuit board accommodated in the cavity, and a shell cover is fixedly connected to a position of the second shell part corresponding to the opening.

[0018] Furthermore, a power converter is fixedly installed at the joint of the first shell part and the second shell part, the acquisition circuit board is electrically connected to one end of the power converter, and the probe circuit board is electrically connected to the other end of the power converter.

[0019] In summary, the present invention has the following beneficial effects:

[0020] 1. The sensor detection probe adopts a smooth transition arc design. When pouring epoxy resin, stress concentration areas such as right angles are reduced, and there is no dead angle for injection, so that the epoxy resin can be fully filled, reducing the risk of cracking of the glue layer caused by curing stress. At this time, the epoxy resin can more easily form a thinner epoxy resin layer during pouring, while ensuring the insulation and protection strength, further reducing the amount of epoxy resin poured, and the arc design of the first shell can greatly reduce the overall mass of the sensor;

[0021] 2. The gap measurement coil group is the front end of the entire sensor measurement and is the core component of eddy current induction. This product adopts the combination of "circular gap measurement coil I" + "square gap measurement coil II", where the circular gap measurement coil I is located at the front end of the probe plane, and its size is set according to the maximum inscribed circle of the probe circuit board to match the U-shaped arc design of the sensor head; the square gap measurement coil II is arranged in sequence behind the circular gap measurement coil I, and the side length is kept consistent with the radial size of the probe circuit board as much as possible to ensure that its area is maximized, which has advantages in parameters such as measurement range, sensitivity and linearity;

[0022] 3. The probe circuit board adopts a flexible circuit board, and the gap measurement coil group is coated on the flexible circuit board in the form of copper. Compared with the traditional copper-clad PCB coil structure, the thermal expansion coefficient of the flexible circuit board is better matched with the PMI skeleton and the outer epoxy resin. The stress caused by thermal expansion under temperature changes is smaller, so the internal parameters of the coil change less under high temperature conditions, and the temperature drift characteristics of the sensor are better; at the same time, the flexible circuit board is thinner and lighter (the layer thickness can be reduced by 1.5mm), and the sensor can be further reduced in size and weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure decomposition of the present invention.

[0024] Figure 2 It is a schematic diagram of the overall structure decomposition of the probe circuit board and the coil frame of the present invention when positioning holes are provided.

[0025] Figure 3 It is a schematic diagram of the overall structure decomposition when the coil frame of the present invention is provided with an accommodating space.

[0026] In the figure: 10, shell; 11, first shell part; 111, arc-shaped annular wall; 12, second shell part; 121, shell cover; 20, control unit; 30, probe unit; 31, gap measurement coil group; 311, gap measurement coil I; 312, gap measurement coil II; 32, probe circuit board; 321, second arc-shaped end; 33, coil frame; 331, first arc-shaped end; 332, accommodating space; 34, positioning hole; 40, epoxy resin layer. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the accompanying drawings.

[0028] like Figure 1-3 As shown, a suspension gap sensor for medium and low speed maglev trains is installed between the end of the electromagnet and the F-type track, at the bottom of the F-track, with its sensing surface facing the bottom surface of the F-track, and the object to be measured is a metal plane. The suspension gap sensor of the present invention includes a housing 10, a control unit 20 and a probe unit 30, which constitute the basic structure of the present invention.

[0029] The shell 10 includes a first shell portion 11 and a second shell portion 12 which are arranged in an L shape. A power converter is arranged at the connection between the first shell portion 11 and the second shell portion 12. The power converter includes but is not limited to a pin-type structure. The other end of the first shell portion 11 away from the second shell portion 12 is arranged as an arc-shaped annular wall 111. Specifically, the end of the first shell portion 11 is a semicircular structure, and the first shell portion 11 as a whole is a U-shaped structure.

[0030] The control unit 20 is fixedly installed in the second housing portion 12 . The control unit 20 is a prior art and is not an innovation of the present invention, and thus will not be described in detail.

[0031] The probe unit 30 includes a gap measuring coil group 31, a probe circuit board 32 and a coil skeleton 33 which are fixed in the first shell part 11 from top to bottom in sequence. The coil skeleton 33 is arranged at the other side away from the control unit 20 as a first arc-shaped end 331 adapted to the arc-shaped ring wall 111. The probe circuit board 32 is electrically connected to the control unit 20. The probe circuit board 32 is arranged at the other side of the control unit 20 as a second arc-shaped end 321. The gap measuring coil group 31 includes a gap measuring coil I311 arranged laterally spaced apart and at least one gap measuring coil II312. Preferably, in the present invention, two gap measuring coils II312 are provided. The gap measuring coil I311 is arranged as a circular ring structure and its outer diameter is adapted to the second arc-shaped end 321 of the probe circuit board 32. The gap measuring coil II312 is a rectangular structure. The first shell part 11 is filled with an epoxy resin adhesive layer 40 so that the probe unit 30 is sealed and coated between the first shell part 11 and the epoxy resin adhesive layer 40.

[0032] The sensor detection probe of the present invention adopts a smoothly transitioned arc-shaped design. When encapsulating epoxy resin, stress concentration areas such as right angles are reduced, and there are no dead corners for injection, so that the epoxy resin can be fully filled, reducing the risk of cracking of the glue layer due to curing stress. At this time, the epoxy resin can more easily form a thinner epoxy resin glue layer 40 during encapsulation, while ensuring the insulation and protection strength, further reducing the amount of epoxy resin injection. Combined with the arc-shaped design of the first outer shell, the overall mass of the sensor can be greatly reduced.

[0033] In some embodiments, the probe circuit board 32 is a flexible circuit board, and the gap measurement coil group 31 is coated on the flexible circuit board in the form of copper cladding. Compared with the hard circuit board, the flexible circuit board is thinner and lighter (the layer thickness can be reduced by 1.5mm), and the sensor can be further reduced in size and weight. Furthermore, the coil skeleton 33 is made of PMI material, and the thermal expansion coefficients of the probe circuit board 32, the coil skeleton 33 and the epoxy resin layer 40 are matched. The probe circuit board 32 is a flexible circuit board, and the gap measurement coil group 31 is coated on the flexible circuit board in the form of copper cladding. Compared with the traditional copper-clad PCB coil structure, the thermal expansion coefficients of the flexible circuit board, the PMI skeleton and the outer epoxy resin are better matched, and the stress caused by thermal expansion under temperature changes is smaller, so the internal parameters of the coil change less under high temperature conditions, and the temperature drift characteristics of the sensor are better.

[0034] The use of thin-layer flexible circuit boards, on the one hand, ensures the matching of thermal expansion coefficients between various components, and on the other hand, the vertical dimensional change is very small, thereby reducing the thermal stress on the gap measurement coil I311 and the gap measurement coil II312. Therefore, the influence of temperature changes on the parameters of the gap measurement coil I311 and the gap measurement coil II312 is reduced, and the data within the expected measurement range is more detailed and accurate.

[0035] In some embodiments, the second arc-shaped end 321 matches the first arc-shaped end 331, so that the second arc-shaped end 321 is compatible with the arc-shaped annular wall 111. In this embodiment, during assembly, the probe circuit board 32 is first bonded to the coil skeleton 33. Although the probe circuit board 32 and the coil skeleton 33 may be offset by gluing, the probe circuit board 32 and the coil skeleton 33 are designed to match the inner cavity of the first shell portion 11, so that the probe circuit board 32 and the coil skeleton 33 can be positioned by the shell wall of the first shell portion 11, thereby correcting the offset between the probe circuit board 32 and the coil skeleton 33.

[0036] In some embodiments, the upper end of the coil skeleton 33 is provided with a receiving space 332 that matches the shape of the probe circuit board 32, and the probe circuit board 32 is at least partially received in the receiving space 332. Through the above configuration, the probe circuit board 32 can be directly placed in the receiving space 332, thereby playing a positioning role. The probe circuit board 32 and the coil skeleton 33 are fixed by glue, and the probe circuit board 32 is positioned by the receiving space 332 to solve the problem of low assembly precision caused by the offset of the probe circuit board 32 and the coil skeleton 33 when they are glued together during assembly.

[0037] In some embodiments, the gap measurement coil group 31 and the probe circuit board 32 are all in the accommodating space 332, and the end of the gap measurement coil group 31 is in contact with the inner wall of the accommodating space 332 of the coil skeleton 33. This solution optimizes the structural design and process, especially the structural design in which the coil skeleton 33 surrounds the gap measurement coil I311 and the gap measurement coil II312, so that the gap measurement coil I311 and the gap measurement coil II312 are more accurately positioned and more tightly combined with the coil skeleton 33 in the vertical direction; at the same time, the arc-shaped design of the end of the first shell portion 11 is conducive to achieving a denser sealing effect on the outside of the first shell portion 11, thereby completing an overall optimization and obtaining accurate measurement results.

[0038] In some embodiments, the gap measurement coil II312 is a square coil, and the side length of the gap measurement coil II312 is consistent with the width of the probe circuit board 32. At this time, since the gap measurement coil group 31 is the front end of the entire sensor measurement, it is the core component of eddy current induction. According to the same area and number of turns, the sensor measurement range of the circular gap measurement coil group 31 is the largest, the sensitivity is the highest, and the linearity is the best; according to the unchanged coil diameter, the square gap measurement coil group 31 has the largest area. This product adopts the combination of "circular gap measurement coil I311" + "square gap measurement coil II312", in which the circular gap measurement coil I311 is located at the front end of the probe plane, and the size is set according to the maximum inscribed circle of the probe circuit board 32 to match the U-shaped arc design of the sensor head; the square gap measurement coil II312 is arranged in sequence behind the circular gap measurement coil I311, and the side length is kept consistent with the radial size of the probe circuit board 32 as much as possible to ensure that its area is the largest, and it has advantages in parameters such as measurement range, sensitivity and linearity.

[0039] In some embodiments, the coil skeleton 33 and the probe circuit board 32 are respectively provided with corresponding positioning holes 34. When assembled, the fastener passes through the positioning holes 34 of the coil skeleton 33 and the probe circuit board 32 and is fixedly connected to the first housing portion 11. In this embodiment, the probe circuit board 32 and the coil skeleton 33 are both provided with positioning holes 34, and the positioning holes 34 of the probe circuit board 32 and the coil skeleton 33 are fixed to the housing through the positioning holes 34, that is, they are fixed by assembling the two positioning holes 34 with fasteners. This structural design eliminates the bonding and fixing method of the probe circuit board 32 and the coil skeleton 33. In addition, since the flexible circuit board is relatively thin and has a large plane, the adhesive is easily unevenly applied during manual bonding, and the adhesive layer is uneven, which easily leads to differences in the detection spacing of the different channel gap measurement coil groups 31, and the consistency of the sensor is relatively difficult to control; by providing a structure with an accommodating space 332, the flexible circuit board (coil) and the coil skeleton 33 are more likely to maintain synchronous positioning, and the consistency of the suspension gap sensor of the present invention will be greatly improved.

[0040] In some embodiments, the second housing portion 12 is provided with a cavity with a side opening, and the control unit 20 includes at least one acquisition circuit board accommodated in the cavity. A shell cover 121 is fixedly connected to the position of the second housing portion 12 corresponding to the opening, and the shell cover 121 is detachably connected to the second housing portion 12. In the present invention, two groups of acquisition circuit boards are provided. The shell cover 121 and the second housing portion 12 are fastened by 10 M4 screws, and a sealing strip is provided in the middle to play a waterproof role.

[0041] In some embodiments, a power converter is fixedly installed at the joint of the first shell portion 11 and the second shell portion 12, the acquisition circuit board is electrically connected to one end of the power converter, and the probe circuit board 32 is electrically connected to the other end of the power converter. Through this arrangement, the efficiency of the electrical connection between the acquisition circuit board and the probe circuit board 32 is greatly improved.

[0042] The material of the shell 10 is preferably aluminum alloy, and the wall thickness of the aluminum alloy shell 10 is 4 mm, which not only meets the strength requirements but also takes into account the lightweight design.

[0043] The packaging process of the probe unit 30 includes the following steps:

[0044] 1) Assemble the assembled probe unit 30 into the housing and perform epoxy resin potting with the glue potting tool;

[0045] 2) Preheat the main agent of epoxy resin glue before potting to improve its fluidity;

[0046] 3) Mix the two components of the epoxy resin glue evenly according to the ratio, then evacuate and fully degas;

[0047] 4) Use tools such as syringes and pressure injection equipment to apply glue from the injection port;

[0048] 5) After potting, the epoxy resin needs to be cured at high temperature and then slowly cooled down to room temperature.

[0049] After the gap measurement coil group 31, the probe circuit board 32 and the coil frame 33 are assembled, the outer surfaces are sealed with epoxy resin glue through a tooling to play the role of protection, waterproofing and insulation.

[0050] The above description is only a preferred embodiment of the present invention, so all equivalent changes or modifications made according to the structure, characteristics and principles described in the scope of the patent application of the present invention are included in the scope of the patent application of the present invention.

Claims

1. A suspension gap sensor for medium and low speed maglev trains, characterized in that: include A housing (10), the housing (10) comprising a first housing portion (11) and a second housing portion (12) arranged in an L-shape, wherein the other end of the first housing portion (11) away from the second housing portion (12) is arranged as an arc-shaped annular wall (111); A control unit (20), the control unit (20) being fixedly installed in the second housing portion (12); The probe unit (30) comprises a gap measuring coil group (31), a probe circuit board (32) and a coil frame (33) which are fixed in sequence from top to bottom in the first housing portion (11); the coil frame (33) is arranged on the other side away from the control unit (20) as a first arc-shaped end (331) adapted to the arc-shaped annular wall (111); the probe circuit board (32) is electrically connected to the control unit (20); and the probe circuit board (32) is arranged on the other side relative to the control unit (20) as a second arc-shaped end (321); The gap measurement coil group (31) comprises gap measurement coils I (311) and at least one gap measurement coil II (312) arranged in a transversely spaced relationship. The gap measurement coil I (311) is arranged in a circular ring structure and its outer diameter is matched with a second circular arc end (321) of the probe circuit board (32). The gap measurement coil II (312) is a rectangular structure. An epoxy resin adhesive layer (40) is filled in the first shell part (11) so that the probe unit (30) is sealed and covered between the first shell part (11) and the epoxy resin adhesive layer (40). The probe circuit board (32) is a flexible circuit board, and the gap measurement coil group (31) is coated on the flexible circuit board in the form of copper coating; The coil skeleton (33) is made of PMI material, and the thermal expansion coefficients of the probe circuit board (32), the coil skeleton (33) and the epoxy resin adhesive layer (40) match each other.

2. The suspension gap sensor for medium and low speed maglev train according to claim 1, characterized in that: The second arc-shaped end head (321) matches the first arc-shaped end head (331), so that the second arc-shaped end head (321) is adapted to the arc-shaped annular wall (111).

3. The suspension gap sensor for medium and low speed maglev train according to claim 1, characterized in that: The upper end of the coil frame (33) is provided with a receiving space (332) matching the shape of the probe circuit board (32), and the probe circuit board (32) is at least partially received in the receiving space (332).

4. The suspension gap sensor for medium and low speed maglev train according to claim 1, characterized in that: The gap measurement coil II (312) is a square coil, and the side length of the gap measurement coil II (312) is consistent with the width of the probe circuit board (32).

5. The suspension gap sensor for medium and low speed maglev train according to claim 3, characterized in that: The coil frame (33) and the probe circuit board (32) are respectively provided with corresponding positioning holes (34). During assembly, the fasteners pass through the positioning holes (34) of the coil frame (33) and the probe circuit board (32) and are fixedly connected to the first housing portion (11).

6. The suspension gap sensor for medium and low speed maglev train according to claim 5, characterized in that: The gap measurement coil group (31) and the probe circuit board (32) are all in the accommodation space (332), and the end of the gap measurement coil group (31) is in contact with the inner cavity wall of the accommodation space (332) of the coil frame (33).

7. The suspension gap sensor for medium and low speed maglev train according to claim 1, characterized in that: The second housing portion (12) is provided with a cavity with a side opening, the control unit (20) comprises at least one acquisition circuit board accommodated in the cavity, and a shell cover (121) is fixedly connected to the second housing portion (12) at a position corresponding to the opening.

8. The suspension gap sensor for medium and low speed maglev train according to claim 7, characterized in that: A power converter is fixedly mounted at the junction of the first housing portion (11) and the second housing portion (12); the acquisition circuit board is electrically connected to one end of the power converter; and the probe circuit board (32) is electrically connected to the other end of the power converter.

Images