Proximity sensor based on PCB

Abstract

The utility model discloses a proximity sensor based on a PCB. The proximity sensor comprises a shell, and an induction assembly, a spring and a check ring which are sequentially arranged in an inner cavity of the shell from left to right. Wherein one end of the spring is installed on the pressing ring of the check ring, the other end of the spring is connected with the induction assembly, the induction assembly comprises a PCB coil and an iron core, a rubber pad is arranged between the PCB coil and the iron core, and the PCB coil, the rubber pad and the iron core are fixed through glue. According to the utility model, the PCB coil is used as the sensor part of the proximity sensor and is only influenced by a structural material at high and low temperatures, the temperature drift can be ignored, the PCB processing requirement can be completely met in the PCB manufacturing process in China, and the PCB coil produced by the same PCB manufacturing process is very high in consistency, so that the cost is reduced. The temperature drift problem of a traditional proximity sensor and the consistency problem of the sensor are solved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of micro sensor, specifically relates to a proximity sensor based on PCB. BACKGROUND

[0002] The proximity sensor is used for detecting the relative change of target position and outputs continuous inductance signal analog quantity, and when the target is close to the induction surface of the proximity sensor, the inductance signal gradually increases, and when the target is away from the induction surface of the proximity sensor, the inductance signal gradually decreases. The inductance proximity switch has the characteristics of high reliability, wide temperature working range, high precision and anti-disturbance, and has been widely applied to various aerospace airborne equipment.

[0003] With the high-speed development of the industry of our country, the requirements for various sensors are higher and higher, various use environments are more severe, especially the aviation equipment needs to have the characteristics of high quality and high performance during combat, and the performance should be guaranteed as much as possible without attenuation in various temperature environments. Therefore, the performance of equipment needs to be improved from the most basic equipment sense organ. As a part of the equipment sense organ, the sensor needs to be improved from the sensor.

[0004] The proximity sensor needs to be improved from the design source and start from the sensor part by considering another way of thinking. In the process of temperature change, the traditional enameled wire coil has large output change and temperature drift under high and low temperatures, which is determined by the winding structure. The original skeleton winding coil is affected by factors such as winding equipment, coil turnover, high and low temperature circulation and uniformity of enameled wire, so that the distribution relationship between turns and layers of the coil changes to a certain extent, the distribution parameter difference is large, and the inductance discreteness of the coil is large. Therefore, a thought of taking the PCB coil as a sensor is researched, which is applied to the sensor, that is, the proximity sensor based on PCB. Utility model content

[0005] In view of the above-mentioned deficiencies in the prior art, the proximity sensor based on PCB solves the problems of temperature drift and sensor consistency of the traditional proximity sensor.

[0006] In order to achieve the above-mentioned invention purposes, the utility model adopts the technical scheme that a proximity sensor based on PCB, including shell and the inside cavity of shell sets in turn from left to right induction assembly, spring and baffle ring,

[0007] Among them, one end of the spring is installed on the pressing ring of the baffle ring, the other end of the spring is connected with the induction assembly, the induction assembly includes PCB coil and iron core, rubber pad is arranged between the PCB coil and the iron core, and the PCB coil, the rubber pad and the iron core are fixed by adhesion.

[0008] Further, the material of the shell is austenitic stainless steel.

[0009] Further, an insulating film is arranged between the inductive component and the shell.

[0010] Further, the iron core is connected with the adjusting screw.

[0011] Further, the PCB coil is provided with a plurality of connecting holes including blind buried holes and vias.

[0012] The utility model discloses the beneficial effects are:

[0013] (1) the utility model provides a proximity sensor based on PCB, through the coil winding adopts the mode of layout in PCB board through the wire of coil, forms PCB coil, guarantees the high consistency of the coil of winding through the printed board processing technology, according to the temperature characteristic of printed board, it selects high TG's FR4 material, Tg>180 DEG C, makes PCB not easy delamination or deformation in high and low temperature environment, especially suitable for the complex thermal environment of multilayer board, makes PCB coil little deformation under-55 DEG C~70 DEG C wide temperature range, and the gap between layers is stable. k (permittivity) for 4.0~4.2, makes the coil have lower interlayer parasitic capacitance, improves the self-resonant frequency of coil, and expands the high-frequency application range, and its D f (permittivity) ≤0.015, reduces the dielectric loss under high frequency, so that the PCB coil has high quality factor.According to the above design, the PCB coil processed has the characteristics of small temperature drift and high consistency, so that the proximity sensor based on PCB coil greatly improves the debugging efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is a proximity sensor based on PCB schematic diagram.

[0015] Figure 2 It is the schematic diagram of iron core and coil.

[0016] Figure 3 It is the principle block diagram of iron core and coil.

[0017] Wherein: 1, shell, 2, PCB coil, 3, rubber pad, 4, iron core, 5, adjusting screw, 6, spring, 7, pressure ring, 8, retaining ring. DETAILED DESCRIPTION

[0018] The specific embodiments of the utility model are described below so as to make the technical personnel in the art understand the utility model, but it should be clear that the utility model is not limited to the scope of the specific embodiments, and for the ordinary technical personnel in the art, as long as various changes are within the spirit and scope of the utility model defined and determined by the appended claims, these changes are obvious, and all the inventions and creations using the concept of the utility model are within the scope of protection.

[0019] As Figure 1 shown, in an embodiment of the utility model, a proximity sensor based on PCB, characterized in that, including shell 1, and the inside cavity of shell 1 is sequentially arranged from left to right induction assembly, spring 6 and baffle ring 8;

[0020] Wherein, one end of spring 6 is installed on the pressing ring 7 of baffle ring 8, the other end of spring 6 is connected with induction assembly, induction assembly includes PCB coil 2 and iron core 4, and rubber pad 3 is arranged between PCB coil 2 and iron core 4, and PCB coil 2, rubber pad 3 and iron core 4 are fixed by gluing.

[0021] Spring 6 is added between induction assembly and baffle ring 8, for making induction assembly can keep certain pre-pressure, eliminate the gap between induction assembly and shell 1, and also play the role of shock absorption;The other end of spring 6 is installed on pressing ring 7 in cooperation, and is fixed by the way of bonding with DG-4 adhesive between contact ring surface, for removing the design of structural strength under the condition that each component has sufficient strength, to realize the light weight of product.

[0022] The beginning and the end on PCB coil 2 are led out by wire, PCB coil 2 and iron core 4 are protected, damped and insulated by rubber pad 3, and one circle of insulating tape is wound on the column of iron core 4.

[0023] The material of shell 1 is austenitic stainless steel. Shell 1 forms a sealed cavity by epoxy resin pouring, so that the product has high mechanical strength, strong corrosion resistance and good sealing and waterproof performance.

[0024] Insulating film is arranged between induction assembly and shell 1, for ensuring the electrical isolation between PCB coil 2 and iron core 4, and meeting the requirement of insulation strength.

[0025] Iron core 4 is connected with adjusting screw 5.

[0026] A plurality of connecting holes are arranged on the plate of PCB coil 2, including blind buried hole and via hole. PCB coil 2 adopts two kinds of interlayer connection modes, which are respectively blind buried hole or via hole interlayer connection, and the inductance value is adjusted to the required value by the way of adjusting the internal adjusting screw 5 with iron core 4.

[0027] The total turns of the PCB coil 2 in the embodiment can be adjusted according to the position detection distance of the sensor, the layer number of the PCB coil 2 can satisfy 24 layers, the single layer is about 12-13 turns, the total turns can reach more than 300 turns, and according to the process level of the manufacturer, the coil layer number and the total turns can be improved.

[0028] As shown in Figures 2-3 The change of the air gap of the core coil magnetic circuit causes the change of the magnetic resistance of the magnetic circuit, so as to change the self-inductance of the coil. As long as the air gap parameter changes, the magnetic resistance in the magnetic circuit will change, so as to cause the change of the inductance of the inductance coil, and thus the relative position information between the target and the sensor sensing surface is obtained by measuring the change of the inductance.

[0029] The working process of the system is as follows: the proximity sensor based on the PCB is used for detecting the position state of the target, and the inductance corresponding to the position is output. When the position between the target and the product sensing surface changes, the air gap of the core coil magnetic circuit changes, causing the change of the magnetic resistance of the magnetic circuit, so as to change the size of the self-inductance of the coil. As long as the air gap parameter changes, the magnetic resistance in the magnetic circuit will change, so as to obtain the relative position information between the target and the sensor sensing surface. When the target is close, the air gap decreases, the magnetic resistance decreases, the magnetic flux increases, and the inductance increases. When the target is far away, the air gap increases, the magnetic resistance increases, the magnetic flux decreases, and the inductance decreases.

[0030] In the description of the present application, it should be understood that the terms "center", "thickness", "upper", "lower", "horizontal", "top", "bottom", "inner", "outer", "radial" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. Therefore, the features limited by "first", "second", "third" can explicitly or implicitly include one or more features.

Claims

1. A PCB-based proximity sensor, characterized by, The shell (1) and the internal cavity of the shell (1) are sequentially provided with an induction assembly, a spring (6) and a check ring (8) from left to right; Wherein, one end of the spring (6) is installed on the pressing ring (7) of the check ring (8), the other end of the spring (6) is connected with the induction assembly, the induction assembly comprises a PCB coil (2) and an iron core (4), a rubber pad (3) is arranged between the PCB coil (2) and the iron core (4), and the PCB coil (2), the rubber pad (3) and the iron core (4) are fixed by gluing.

2. The PCB-based proximity sensor of claim 1, wherein, The material of the shell (1) is austenitic stainless steel.

3. The PCB-based proximity sensor of claim 1, wherein, An insulating film is arranged between the induction assembly and the shell.

4. The PCB-based proximity sensor of claim 1, wherein, The iron core (4) is connected with an adjusting screw (5).

5. The PCB-based proximity sensor of claim 1, wherein, A plurality of connecting holes are arranged on the PCB coil (2), including blind buried holes and through holes.

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