A detection sensor

Abstract

The application provides a detection sensor, comprising: m PCB plate groups arranged in sequence along the circumference of a ball passing pipe, two sides of each PCB plate group are respectively a recessed side and a convex side, the recessed side faces the outer circumferential surface of the ball passing pipe, and the convex side faces away from the outer circumferential surface of the ball passing pipe, and m is greater than or equal to 2; each PCB plate group comprises two conductive structures arranged in sequence in the axial direction of the ball passing pipe, each conductive structure comprises a coil; in the m conductive structures arranged in sequence on the same circumference outside the ball passing pipe: the first end of the first conductive structure and the second end of the last conductive structure are arranged to be electrically connected with a detection instrument, the second end of the Kth conductive structure is electrically connected with the first end of the K+1th conductive structure to form a detection coil, and the total 2m conductive structures form two detection coils on two circumferences outside the ball passing pipe, and K is equal to 1 to (m-1). The scheme can effectively reduce the space occupied by the PCB plate group in the radial direction of the ball passing pipe.

Description

Technical Field

[0001] This utility model relates to the field of nuclear energy equipment technology, and more specifically, to a detection sensor. Background Technology

[0002] Nuclear energy is a highly efficient and clean energy source. As a "fourth-generation nuclear reactor," the pebble bed high-temperature gas-cooled nuclear reactor (HTGR) possesses inherent safety advantages and can complete fuel loading and unloading without shutting down the reactor, making it highly valued by many countries. To calculate the remaining nuclear fuel in the reactor core, it is necessary to reliably detect the graphite-based fuel spheres entering and leaving the core, recording the number of fuel spheres loaded and unloaded. Detection sensors (which can be sphere detection sensors or sphere velocity sensors) are the devices used to detect and count the fuel spheres in the pebble bed HTGR, and are a crucial guarantee for the normal operation of the reactor.

[0003] Current detection sensors are mostly based on the eddy current detection principle, employing coils with specific structures. Commonly used coils fall into two categories: semi-circular outer-coated coils and circular placement coils. Both types are typically made by winding enameled wire, requiring processes such as coil winding, vacuum impregnation, and epoxy encapsulation. These processes are done manually, resulting in high manufacturing costs and difficulty in ensuring parameter consistency. Furthermore, the semi-circular outer-coated coil, due to its concave shape and lack of tension, also complicates production tools and processes, increasing costs and making parameter consistency difficult to guarantee. While circular placement coils are relatively easier to manufacture than semi-circular outer-coated coils, their smaller diameter, required for close proximity to the pipe and continuous ball detection, results in weaker eddy currents within the fuel ball and a weaker detection signal, causing inconvenience in use.

[0004] Some detection sensors also use multilayer PCB coil boards or flexible FPCB coils. However, the side of the PCB coil board is perpendicular to the axis of the ball-passing pipe, occupying a large space in the radial direction of the ball-passing pipe; FPCB coils are prone to deformation, difficult to fix stably, and cannot guarantee the consistency of the detection sensor parameters. Utility Model Content

[0005] This utility model embodiment provides a detection sensor, including: m curved PCB board groups, the m PCB board groups are arranged sequentially along the circumference of a ball-passing pipe, each PCB board group has two sides, a concave side and a convex side, the concave side faces the outer circumferential surface of the ball-passing pipe and the convex side faces away from the outer circumferential surface of the ball-passing pipe, m≥2; each PCB board group includes two conductive structures arranged sequentially along the axial direction of the ball-passing pipe, each conductive structure includes a coil; among the m conductive structures arranged sequentially on the same circumference outside the ball-passing pipe: the first end of the first conductive structure and the second end of the last conductive structure are electrically connected to a detection instrument, the second end of the Kth conductive structure is electrically connected to the first end of the K+1th conductive structure to form a detection coil, all 2m conductive structures form two detection coils on the two circumferences outside the ball-passing pipe, K∈1~(m-1).

[0006] In some exemplary embodiments, the winding directions of the coils on adjacent detection coils are opposite.

[0007] In some exemplary embodiments, the first end and the second end of each of the conductive structures are located at the two ends of the corresponding PCB board assembly in the circumferential direction of the ball-passing conduit.

[0008] In some exemplary embodiments, each PCB board group includes p curved PCB boards arranged radially in sequence in the ball-passing pipe, each PCB board includes 2 conductive units arranged axially in the ball-passing pipe, each conductive unit includes the coil, and the p conductive units of each group arranged radially in the ball-passing pipe are electrically connected to form a conductive structure, where p ≥ 2.

[0009] In some exemplary embodiments, the thickness t of each PCB board is no greater than 1 mm, and the length difference between any two adjacent PCB boards in the p PCB boards of each PCB board group in the circumferential direction of the ball-passing pipe is (2π*t) / m.

[0010] In some exemplary embodiments, the p conductive units of each conductive structure are connected in series sequentially.

[0011] In some exemplary embodiments, the p conductive units of each conductive structure are connected in parallel with each other.

[0012] In some exemplary embodiments, each of the conductive units of the PCB board includes q layers of coils, and the q layers of coils of each conductive unit are electrically connected, where q ≥ 2.

[0013] In some exemplary embodiments, the winding directions of the m*p*q coils on the same detection coil are the same, and the winding directions of the coils on adjacent detection coils are opposite.

[0014] In some exemplary embodiments, the coils of each conductive unit's q-layer are separated by an insulating layer and electrically connected through conductive holes passing through the insulating layer; In the radial direction of the ball-passing pipe: a first insulating pad is provided between the recessed side and the ball-passing pipe, and a second insulating pad is provided between adjacent PCB boards in the radial direction of the ball-passing pipe.

[0015] In some exemplary embodiments, the coils of the q-layer of each conductive unit are connected in series.

[0016] In some exemplary embodiments, m is 2~4, p is 2~4, and q is 4~8.

[0017] In some exemplary embodiments, the width of each coil in the axial direction of the ball-passing conduit is d / 2, where d is the diameter of the fuel ball.

[0018] In some exemplary embodiments, if the detection sensor is a ball-passing detection sensor, the center distance between adjacent coils in the axial direction of the ball-passing pipe is d / 2, where d is the diameter of the fuel ball; if the detection sensor is a ball-passing speed sensor, the center distance between adjacent coils in the axial direction of the ball-passing pipe is d~1.15d, where d is the diameter of the fuel ball.

[0019] In some exemplary embodiments, m and p are both 2, q is 6, K is 1, the two conductive units of each conductive structure are connected in parallel, the six coils of each conductive unit are connected in series, each coil has 20 turns, a line width of 15 mil, a line thickness of 2 oz, and each conductive unit has an inductance of 1.55 mH to 1.65 mH and a resistance of 34 Ω to 38 Ω.

[0020] In some exemplary embodiments, the detection sensor further includes: an annular mounting frame comprising m sub-frames arranged sequentially around the circumference of the ball-passing pipe, each sub-frame having an arc-shaped positioning groove extending through the circumference of the ball-passing pipe on its arc-shaped side facing the ball-passing pipe, the m PCB board groups being encapsulated and fixed in the m arc-shaped positioning grooves one-to-one, the first end and the second end of each detection coil being led out of the mounting frame from between adjacent sub-frames via a first wire, and the second end of the Kth conductive structure in each detection coil being connected to the first end of the (K+1)th conductive structure via a second wire.

[0021] In some exemplary embodiments, the detection sensor further includes: an annular shield with a split structure in the circumferential direction of the ball-passing pipe, sleeved on the outside of the ball-passing pipe, the inner circumferential surface of the shield having an annular groove, the mounting frame being accommodated in the annular groove, the shield having a wiring terminal, the wiring terminal having an external wiring part and four internal wiring parts, the four first wires being electrically connected to the four internal wiring parts one by one, the external wiring part being configured to be electrically connected to the detection instrument, the detection instrument being a ball-passing detection instrument.

[0022] In some exemplary embodiments, the shielding cover is provided with a positioning structure that cooperates with the mounting frame and is configured to prevent the mounting frame from moving and rotating within the shielding cover.

[0023] The detection sensor provided in this application embodiment has a curved PCB board assembly. Each PCB board assembly has a concave side and a convex side on its two sides. The concave side faces the outer peripheral surface of the ball-passing pipe, and the convex side faces away from the outer peripheral surface of the ball-passing pipe. This design can effectively reduce the radial space occupied by the PCB board assembly in the ball-passing pipe. Moreover, the PCB board assembly has a certain structural strength and can be stably fixed to the outer peripheral surface of the ball-passing pipe without deformation, which can better ensure the parameter consistency of the detection sensor. Furthermore, the coil of each conductive structure is also closer to the ball-passing pipe, so the mutual inductance between the fuel ball and the coil is stronger, and the change in inductance of the detection coil is greater when the fuel ball passes through the detection coil.

[0024] Other features and advantages of this invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained by means of the structures particularly pointed out in the description and the drawings. Attached Figure Description

[0025] The accompanying drawings are provided to further illustrate the technical solution of this utility model and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solution of this utility model and do not constitute a limitation on the technical solution of this utility model.

[0026] Figure 1 A cross-sectional view of the detection sensor provided in some embodiments of this utility model applied to a ball-passing pipe; Figure 2 for Figure 1 A schematic diagram of the transverse cross-sectional structure of the detection sensor in the image; the coil is not shown. Figure 3 for Figure 1 A schematic diagram of the main structure of a coil; Figure 4 for Figure 1 A schematic diagram of the main structure of another type of coil in the diagram; Figure 5 A longitudinal sectional view of the detection sensor provided in some embodiments of this utility model applied to a ball-passing pipe; Figure 6 This is a schematic diagram of the subframe structure in some embodiments of the present invention; Figure 7 This is a schematic diagram of the shielding cover in some embodiments of the present invention.

[0027] The correspondence between the reference numerals and the component names is as follows: 100 PCB board assembly, 101 Recessed side, 102 Raised side, 110 PCB board, 120 Conductive unit, 121 Coil, 122 Insulating layer, 123 Conductive hole, 130 Detection coil, 140 Second conductor, 150 First conductor, 160 Third conductor, 170 Conductive structure, 200 Ball-passing pipe, 300 Fuel ball, 410 First insulating pad, 420 Second insulating pad, 510 Sub-frame, 511 Arc-shaped positioning groove, 600 Shielding cover, 610 Annular groove. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

[0029] The detection sensor provided in the embodiments of this application, such as Figures 1 to 5 As shown, it includes: m curved PCB board groups 100, the m PCB board groups 100 being arranged sequentially along the circumference of the ball-passing pipe 200, each PCB board group 100 having two sides, namely a concave side 101 and a convex side 102 (e.g., Figure 2As shown), the concave side 101 faces the outer peripheral surface of the ball-passing pipe 200, and the convex side 102 faces away from the outer peripheral surface of the ball-passing pipe 200, m≥2; each PCB board assembly 100 includes two conductive structures 170 arranged sequentially along the axial direction of the ball-passing pipe 200, each conductive structure 170 including a coil 121; among the m conductive structures 170 arranged sequentially on the same circumference outside the ball-passing pipe 200: the first end of the first conductive structure 170 and the second end of the last conductive structure 170 are electrically connected to the detection instrument, the second end of the Kth conductive structure 170 is electrically connected to the first end of the K+1th conductive structure 170 to form a detection coil 130 (the m conductive structures 170 arranged sequentially on the same circumference outside the ball-passing pipe 200 are electrically connected to form a detection coil 130), all 2*m conductive structures 170 form two detection coils 130 on the two circumferences outside the ball-passing pipe 200 (in conjunction with Figure 2 and Figure 5 (For understanding), two detection coils 130 are sequentially set along the axial direction of the ball-passing pipe 200, K∈1~(m-1).

[0030] In the m conductive structures 170 arranged sequentially on the same circumference outside the ball-passing pipe 200: the second end of the Kth conductive structure 170 is electrically connected to the first end of the (K+1)th conductive structure 170 to form a detection coil 130, where K∈1~(m-1). For m=2, k is 1. In the two conductive structures 170 arranged sequentially on the same circumference outside the ball-passing pipe 200: the second end of the first conductive structure 170 is electrically connected to the first end of the second conductive structure 170 to form a detection coil 130. For m=3, k is 1 and 2. In the three conductive structures 170 arranged sequentially on the same circumference outside the ball-passing pipe 200: the second end of the first conductive structure 170 is electrically connected to the first end of the second conductive structure 170, and the second end of the second conductive structure 170 is electrically connected to the first end of the third conductive structure 170. The detection coil 130 is formed by connecting the components. For m=4, k is 1, 2, and 3. Among the four conductive structures 170 arranged sequentially on the same circumference outside the ball pipe 200: the second end of the first conductive structure 170 is electrically connected to the first end of the second conductive structure 170, the second end of the second conductive structure 170 is electrically connected to the first end of the third conductive structure 170, and the second end of the third conductive structure 170 is electrically connected to the first end of the fourth conductive structure 170 to form the detection coil 130. Of course, m can also be 5, 6, or 7, etc., which will not be elaborated here.

[0031] The detection sensor has a curved PCB board assembly 100. Each PCB board assembly 100 has two sides, a concave side 101 and a convex side 102. The concave side 101 faces the outer peripheral surface of the ball-passing pipe 200, and the convex side 102 faces away from the outer peripheral surface of the ball-passing pipe 200. This design can effectively reduce the radial space occupied by the PCB board assembly 100 in the ball-passing pipe 200. Moreover, the PCB board assembly 100 has a certain structural strength and can be stably fixed to the outer peripheral surface of the ball-passing pipe 200 without deformation, which can better ensure the parameter consistency of the detection sensor. Furthermore, the coil 121 of each conductive structure 170 is also closer to the ball-passing pipe 200, so the mutual inductance between the fuel ball 300 and the coil 121 is stronger, and the change in inductance of the detection coil is greater when the fuel ball 300 passes through the detection coil 130.

[0032] The detection sensor utilizes the internal electromagnetic field of coil 121 to detect eddy currents in the fuel ball 300. That is, eddy currents exist within the fuel ball 300. When the fuel ball 300 sequentially passes through two adjacent detection coils 130, the eddy currents in the fuel ball 300 cause a change in the impedance of coil 121. The detection instrument detects this change in impedance between the two adjacent detection coils 130, thus achieving the ball-passing detection. This scheme achieves a high signal-to-noise ratio. The detection instrument is a ball-passing detection instrument.

[0033] In some examples, such as Figure 3 and Figure 4 As shown, the winding directions of the coils 121 on adjacent detection coils 130 are opposite, so the impedance change of the two adjacent detection coils 130 is more obvious and easier for the detection instrument to detect (i.e., easier for the detection instrument to detect the impedance change of the two adjacent detection coils 130).

[0034] In some examples, such as Figure 1 and Figure 2 As shown, the first and second ends of each conductive structure 170 are located one-to-one at the two ends of the corresponding PCB board group 100 in the circumferential direction of the ball-passing pipe 200, which makes it easier for the m conductive structures 170 of each detection coil 130 to be connected in series sequentially.

[0035] In some examples, such as Figure 1 , Figure 2 and Figure 5As shown, each PCB board group 100 includes p curved PCB boards 110 arranged radially in sequence in the ball pipe 200 (i.e., each PCB board group 100 includes p PCB boards 110 arranged radially in sequence in the ball pipe 200, and each PCB board 110 is curved in the circumferential direction of the ball pipe 200). Each PCB board 110 includes two conductive units 120 arranged axially in the ball pipe 200. Each conductive unit 120 includes a coil 121. The p conductive units 120 arranged radially in each group are electrically connected and form a conductive structure 170 (therefore, a total of 2*m conductive structures 170 are formed, and each conductive structure 170 includes p electrically connected conductive units 120), where p ≥ 2. Alternatively, each PCB board group 100 may include one PCB board 110 arranged radially in the ball-passing pipe 200 (in this way, each conductive structure 170 includes a conductive unit 120). The PCB board 110 is a curved structure in the circumferential direction of the ball-passing pipe 200, which can also achieve the purpose of this application. Its purpose has not deviated from the design concept of this utility model, and will not be elaborated here. It should also fall within the protection scope of this application. Figure 1 , Figure 2 and Figure 5 P is 2.

[0036] Alternatively, each conductive structure 170 can have its p conductive units 120 connected in series, and the series connection of coils 121 can increase the inductance; or it can be, as... Figure 1 , Figure 2 As shown, the p conductive units 120 of each conductive structure 170 are connected in parallel to each other. The parallel connection of the coils 121 can increase the current carrying capacity (the current applied by the detection instrument to the detection sensor); or, some of the p conductive units 120 of each conductive structure 170 can be connected in series and some in parallel, which can increase both the inductance and the current carrying capacity. Those skilled in the art can make reasonable arrangements according to the requirements to ensure that the impedance of the detection coil 130 matches the detection instrument and that the detection coil 130 can be loaded with a detection current that meets the detection requirements.

[0037] In some examples, the PCB board 110 is made into a curved shape by hot pressing and rolling process. The thickness t of each PCB board 110 is designed to be no more than 1 mm to ensure that the coil 121 will not have defects such as wire cracks when the PCB board 110 is bent by hot pressing and rolling process.

[0038] In some examples, such as Figure 1 and Figure 2As shown, the p PCBs 110 of each PCB group 100 are arranged in a concentric circular arc in the radial direction of the ball pipe 200. For any two adjacent PCBs 110 in each PCB group 100, the length of the outer PCB 110 is greater than the length of the inner PCB 110, and the increase is (2π*t) / m, so that the outer PCB 110 can make fuller use of the circumferential space of its circle.

[0039] In some examples, such as Figures 2 to 4 As shown, each conductive unit 120 of each PCB board 110 includes q coils 121 arranged radially in the ball-passing pipe 200 (i.e., each conductive unit 120 of each PCB board 110 includes q layers of coils). The q coils 121 of each conductive unit 120 are electrically connected, where q ≥ 2. Compared to each conductive unit 120 including only one coil 121, this scheme can effectively reduce the number of PCB boards 110 in each PCB board group 100. Of course, each conductive unit 120 can also include only one coil 121, which can also achieve the purpose of this application. Its purpose does not depart from the design concept of this utility model, and will not be elaborated here, but should also fall within the protection scope of this application.

[0040] In some examples, such as Figure 2 As shown, each conductive unit 120 has q coils 121 separated by an insulating layer 122 (which may be made of epoxy resin) and electrically connected through conductive holes 123 passing through the corresponding insulating layer 122 (i.e., two adjacent coils 121 are electrically connected through conductive holes 123 passing through the insulating layer 122 between the two coils 121). The PCB board 110 is manufactured using automated processes, which have the advantages of simple production process, high manufacturing precision, and good consistency of the parameters of the manufactured detection sensor. This detection sensor, when used with a detection instrument, can achieve more accurate ball detection. The winding direction of each (m*p*q) coil 121 on the same detection coil 130 is the same to increase inductance; the winding direction of the coils 121 on adjacent detection coils 130 is opposite to increase the degree of impedance change between adjacent detection coils 130, ensuring that the detection instrument can more accurately detect the fuel ball 300. Figure 2 The value of q is 6, and each PCB110 board has 5 insulating layers 122.

[0041] Among them, such as Figure 1 As shown, in the radial direction of the ball-passing pipe 200: a flexible first insulating pad 410 is provided between the recessed side 101 of the PCB board assembly 100 and the ball-passing pipe 200. The first insulating pad 410 prevents the coil 121 of the recessed side 101 from contacting and electrically connecting with the side wall of the ball-passing pipe 200, and at the same time, the first insulating pad 410 also improves the shock resistance of the detection sensor; as Figure 1 As shown, a flexible second insulating pad 420 is provided between adjacent PCBs 110 in the radial direction of the ball-passing pipe 200. The second insulating pad 420 prevents the coils 121 on opposite sides of any adjacent PCBs 110 in the radial direction of the ball-passing pipe 200 from making contact and thus forming an electrical connection. Simultaneously, the second insulating pad 420 also enhances the shock resistance of the detection sensor. For example, Figure 1 As shown, the first insulating pad 410 and the second insulating pad 420 can be made of polyimide.

[0042] It can be, such as Figure 2 As shown, each conductive unit 120 has q coils 121 connected in series to increase inductance.

[0043] If the inductance of the detection coil 130 is too small to achieve impedance matching with the detection instrument, the number of series-connected conductive units 120 in each conductive structure 170 can be increased to increase the inductance. If the inductance of the detection coil 130 is large enough, but its current-carrying capacity is too small, the number of parallel-connected conductive units 120 in each conductive structure 170 can be increased to increase the current-carrying capacity of the detection coil 130 (the larger the current loaded on the detection coil 130, the stronger the electromagnetic field generated by the detection coil 130, and the stronger the eddy current generated in the fuel ball 300 when it passes through the detection coil 130, making it easier to detect). By reasonably setting the number of conductive units 120 in the conductive structure 170 and reasonably connecting these conductive units 120 in parallel, and by reasonably setting the number of coils 121 in the conductive units 120 and reasonably connecting these coils 121 in series, the impedance of the detection coil 130 can be matched with the detection instrument, and the detection coil 130 can be loaded with a detection current that meets the detection requirements.

[0044] In some examples, m is 2~4, p is 2~4, and q is 4~8. For example... Figure 3 and Figure 4 As shown, in the radial direction of the ball-passing pipe 200 from the inside out, each conductive unit 120 has q coils 121 that are rectangular. The odd-numbered coils 121 are arranged from the outer periphery of the rectangle to the center of the rectangle, and the even-numbered coils 121 are arranged from the center of the rectangle to the outer periphery of the rectangle. This facilitates the sequential series connection of the q coils 121 in each conductive unit 120. The axial width of each coil 121 in the ball-passing pipe 200 is set to d / 2, where d is the diameter of the fuel ball 300. The circumferential angle of each detection coil 130 in the ball-passing pipe 200 is set as close as possible to 2π.

[0045] In some examples, such as Figure 6As shown, the detection sensor further includes: an annular mounting frame, which includes m sub-frames 510 arranged sequentially around the circumference of the ball-passing pipe 200. Each sub-frame 510 has an arc-shaped positioning groove 511 extending through the circumference of the ball-passing pipe 200 on its arc-shaped side facing the ball-passing pipe 200. The m PCB board groups 100 are correspondingly encapsulated and fixed in the m arc-shaped positioning grooves 511. The first and second ends of each detection coil 130 are adjacent and led out of the mounting frame between adjacent sub-frames 510 through a first wire 150. The second end of the Kth conductive structure 170 in each detection coil 130 is adjacent to the first end of the (K+1)th conductive structure 170 and connected in series through a second wire 140. The p conductive units 120 of each conductive structure 170 are electrically connected through a third wire 160. In this application, m is set to 2.

[0046] In some embodiments, such as Figure 6 As shown, the PCB assembly 100 is fixed in the corresponding arc-shaped positioning groove 511 by multiple screws. The first wire 150, the second wire 140, and the third wire 160 are all connected. Epoxy encapsulation adhesive is used to encapsulate the PCB assembly 100 in the arc-shaped positioning groove 511. This solution provides better vibration resistance for the sensor, effectively reducing noise generated by the detection signal. Furthermore, the PCB 110 will not deform during use, better ensuring the stability of the inductance of the coil 121. Alternatively, the subframe 510 can be made of an insulating material, such as polyimide.

[0047] In some examples, such as Figure 7 As shown, the detection sensor also includes: an annular shield 600 with a split structure on the circumference of the ball-passing pipe 200. The shield 600 is fitted over the ball-passing pipe 200, and an annular groove 610 is provided on the inner circumferential surface of the shield 600. The mounting frame is accommodated in the annular groove 610. The shield 600 is used to improve the electromagnetic interference resistance of the detection sensor. The shield 600 is provided with wiring terminals, which have an external wiring part and four internal wiring parts. The four first wires 150 are electrically connected to the four internal wiring parts one by one. The external wiring parts are configured to be electrically connected to the detection instrument, so that the detection instrument can detect the fuel ball 300 through the detection sensor. The detection instrument can be a ball-passing detection instrument.

[0048] In some examples, such as Figure 7As shown, the shielding cover 600 is provided with a positioning structure, which cooperates with the mounting frame and is configured to prevent the mounting frame from moving radially (i.e., radially) or axially (i.e., axially) within the shielding cover 600, and from rotating. The positioning structure includes any one or more of the following: positioning groove, positioning rib, positioning post, and set screw. All of these can achieve the purpose of this application, and their intent does not depart from the design concept of this utility model. Therefore, they will not be described in detail here, and all should fall within the protection scope of this application.

[0049] In some examples, such as Figure 7 As shown, the shielding cover 600 includes two separate covers arranged sequentially in the circumferential direction of the ball-passing pipe 200. One set of opposite ends of the two covers is connected by hinges, and the other set of opposite ends of the two covers is fixedly connected by screws or clips. The wiring terminals are located outside the shielding cover 600 and fixed to the other set of opposite ends of the two covers (see...). Figure 7 (at point k in the middle).

[0050] For a ball-passing detection sensor, the center distance between adjacent coils 121 along the axial direction of the ball-passing pipe 200 is d / 2, where d is the diameter of the fuel ball 300. For a ball-passing speed sensor, the center distance between adjacent coils 121 along the axial direction of the ball-passing pipe 200 is d~1.15d, where d is the diameter of the fuel ball 300.

[0051] In some embodiments, such as Figure 1 , Figure 2 and Figure 5 As shown, m and p are both 2, q is 6, and K is 1. This scheme has two PCB board groups 100 in the circumferential direction of the ball-passing pipe 200. Each PCB board group 100 includes two PCB boards 110 in the radial direction of the ball-passing pipe 200. Each PCB board 110 has a semi-circular arc structure and two conductive units 120 are provided in the axial direction of the ball-passing pipe 200. Two detection coils 130 are formed in the axial direction of the ball-passing pipe 200. The two detection coils 130 are spaced apart in the axial direction of the ball-passing pipe 200 (taking the axial direction as the vertical direction as an example, then the two detection coils 130 are arranged vertically and horizontally), and are located on two circumferences outside the ball-passing pipe 200 (e.g., Figure 5As shown, the positions of the two circumferences correspond to the positions of the two detection coils 130. Each detection coil 130 includes two conductive structures 170, and each conductive structure 170 includes two conductive units 120 (the two conductive units 120 of each conductive structure 170 are arranged sequentially in the radial direction of the ball-passing pipe 200). Each conductive unit 120 includes six coils 121 (the six coils 121 of each conductive unit 120 are arranged sequentially in the radial direction of the ball-passing pipe 200 and separated by an insulating layer 122. That is, in the axial direction of the ball-passing pipe 200, each PCB board 110 includes two conductive units 120, and each conductive unit 120 includes six coils 121 arranged sequentially in the radial direction of the ball-passing pipe 200, with the six coils 121 separated by an insulating layer 122). The wiring terminals are provided with an external wiring part and four internal wiring parts (the four internal wiring parts are electrically connected to the two first ends and two second ends of the two detection coils 130 one-to-one). The two conductive units 120 of each conductive structure 170 are connected in parallel, and the six coils 121 of each conductive unit 120 are connected in series (the first and second ends of each conductive unit 120 are located at both ends of the PCB board 110 in the circumferential direction of the ball-passing pipe 200, which not only facilitates the parallel connection of the two conductive units 120 of each conductive structure 170, but also facilitates the series connection of the two conductive structures 170 of each detection coil 130, and also facilitates the electrical connection of each detection coil 130 to the internal wiring part of the terminal block through the first wire 150). Each coil 121 The number of turns is 20 (ensuring a relatively large wiring area for each coil 121), the line width is 15 mil (ensuring a relatively large line width for each coil 121), and the line thickness is 2 oz (ensuring a relatively large line thickness for each coil 121). Thus, the inductance of each conductive unit 120 is approximately 1.55 mH to 1.65 mH, and the resistance of each conductive unit 120 is approximately 34 Ω to 38 Ω. The inductance of each conductive structure 170 is approximately 1.5 mH to 1.55 mH, and the resistance is 17 Ω to 19 Ω. The resulting detection sensor can be well matched with detection instruments.

[0052] The coil 121 is configured such that the wire thickness of the coil 121 is as large as possible, the number of turns of each coil 121 is set to be the same, and the wire width of the coil 121 is determined according to the wire thickness of the coil 121 and the required detection current.

[0053] In summary, the detection sensor provided in this application has a curved PCB board assembly. Each PCB board assembly has a concave side and a convex side, with the concave side facing the outer circumference of the ball-passing pipe and the convex side facing away from the outer circumference of the ball-passing pipe. This design can effectively reduce the radial space occupied by the PCB board assembly in the ball-passing pipe. Moreover, the PCB board assembly has a certain structural strength and can be stably fixed to the outer circumference of the ball-passing pipe without deformation, which can better ensure the parameter consistency of the detection sensor. Furthermore, the coil of each conductive structure is also closer to the ball-passing pipe, so the mutual inductance between the fuel ball and the coil is stronger, and the change in inductance of the detection coil is greater when the fuel ball passes through the detection coil.

[0054] In the description of this utility model, it should be noted that the terms "upper", "lower", "one side", "the other side", "one end", "the other end", "side", "opposite", "four corners", "periphery", "'mouth' structure", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the structure referred to has a specific orientation, or is constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0055] In the description of the embodiments of this utility model, unless otherwise expressly specified and limited, the terms "connection," "direct connection," "indirect connection," "fixed connection," "installation," and "assembly" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. The terms "installation," "connection," and "fixed connection" can refer to a direct connection or an indirect connection through an intermediate medium, or they can refer to the internal communication between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0056] Although the embodiments disclosed in this utility model are as described above, the content described is only for the purpose of facilitating understanding of this utility model and is not intended to limit this utility model. Any person skilled in the art to which this utility model pertains may make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in this utility model, but the patent protection scope of this utility model shall still be defined by the appended claims.

Claims

1. A detection sensor, characterized in that, include: m curved PCB groups are arranged sequentially along the circumference of the ball-passing pipe. Each PCB group has two sides, a concave side and a convex side, with the concave side facing the outer circumferential surface of the ball-passing pipe and the convex side facing away from the outer circumferential surface of the ball-passing pipe. m≥2. Each of the PCB board groups includes two conductive structures arranged sequentially along the axial direction of the ball-passing pipe, and each conductive structure includes a coil; Of the m conductive structures sequentially arranged on the same circumference outside the ball-passing pipe: the first end of the first conductive structure and the second end of the last conductive structure are electrically connected to the detection instrument; the second end of the Kth conductive structure is electrically connected to the first end of the (K+1)th conductive structure to form a detection coil; all 2m conductive structures form two detection coils on the two circumferences outside the ball-passing pipe, where K∈1~(m-1).

2. The detection sensor according to claim 1, characterized in that: The first and second ends of each conductive structure are located one-to-one at the two ends of the corresponding PCB board assembly in the circumferential direction of the ball-passing channel; or The winding directions of the coils on adjacent detection coils are opposite.

3. The detection sensor according to claim 1, characterized in that, Each PCB board group includes p curved PCB boards arranged radially in sequence in the ball-passing pipe. Each PCB board includes two conductive units arranged axially in sequence in the ball-passing pipe. Each conductive unit includes a coil. The p conductive units in each group arranged radially in sequence in the ball-passing pipe are electrically connected to form a conductive structure, where p ≥ 2.

4. The detection sensor according to claim 3, characterized in that: The thickness t of each PCB board is no greater than 1 mm, and the length difference between any two adjacent PCB boards in the p PCB boards of each PCB board group in the circumferential direction of the ball-passing pipe is (2π*t) / m; or The p conductive units of each conductive structure are connected in series sequentially; or The p conductive units of each conductive structure are connected in parallel to each other.

5. The detection sensor according to claim 4, characterized in that, Each conductive unit of the PCB board includes q layers of coils, and the q layers of coils of each conductive unit are electrically connected, where q ≥ 2.

6. The detection sensor according to claim 5, characterized in that, The coils of each conductive unit's q-layer are separated by an insulating layer and electrically connected through conductive holes passing through the insulating layer. In the radial direction of the ball-passing pipe: a first insulating pad is provided between the recessed side and the ball-passing pipe, and a second insulating pad is provided between adjacent PCB boards in the radial direction of the ball-passing pipe.

7. The detection sensor according to claim 5, characterized in that: The winding directions of m*p*q coils on the same detection coil are the same, and the winding directions of coils on adjacent detection coils are opposite; or The coils of each conductive unit's q-layer are connected in series sequentially.

8. The detection sensor according to claim 5, characterized in that, m is 2~4, p is 2~4, q is 4~8, and the width of each coil in the axial direction of the ball-passing pipe is d / 2; Since the detection sensor is a ball-passing detection sensor, the center distance between adjacent coils in the axial direction of the ball-passing pipe is d / 2; Since the detection sensor is a ball-passing velocity sensor, the center distance between adjacent coils in the axial direction of the ball-passing pipe is d~1.15d, where d is the diameter of the fuel ball.

9. The detection sensor according to any one of claims 1 to 8, characterized in that, Also includes: The annular mounting frame includes m sub-frames arranged sequentially around the circumference of the ball-passing pipe. Each sub-frame has an arc-shaped positioning groove extending through the circumference of the ball-passing pipe on its arc-shaped side facing the ball-passing pipe. The m PCB boards are correspondingly encapsulated and fixed in the m arc-shaped positioning grooves. The first and second ends of each detection coil are led out of the mounting frame from between adjacent sub-frames through a first wire. The second end of the Kth conductive structure in each detection coil is connected to the first end of the (K+1)th conductive structure through a second wire.

10. The detection sensor according to claim 9, characterized in that, Also includes: A split-structure annular shielding cover is fitted over the ball-passing pipe. The inner circumferential surface of the shielding cover has an annular groove, and the mounting frame is accommodated in the annular groove. The shielding cover is provided with wiring terminals, each with an external wiring section and four internal wiring sections. The four first wires are electrically connected to the four internal wiring sections one by one. The external wiring section is configured to be electrically connected to the detection instrument, which is a ball-passing detection instrument.

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