Cylindrical proximity sensor with proximity distance capable of being accurately and finely adjusted and adjustment method

Abstract

The invention belongs to the field of aviation electromechanical systems, and relates to a cylindrical proximity sensor with the proximity distance capable of being accurately and finely adjusted and an adjusting method. Comprising an end cover (1), a check ring (2), a lining (3), a shell (4), a coil assembly (5), a cylindrical iron core (6), a coil sleeve (7), a coil cover (8), a wave spring (9), a conditioning circuit board (10), a mounting frame (11), a coil frame (12) and an enameled wire (13). And the approaching distance between the sensor and the target is adjustable. Through multiple damping structures such as the wave spring and the coil sleeve, the anti-vibration capability of the sensor is improved.

Description

Technical Field

[0001] The invention belongs to the field of aviation electromechanical systems, and relates to a cylindrical proximity sensor with a proximity distance capable of being precisely fine-tuned and an installation and adjustment method. Background Art

[0002] The present invention relates to a cylindrical proximity sensor and an installation method with precise fine adjustment of the approach distance, which are applied to the field of aviation electromechanical systems. The domestic aviation field has only developed proximity sensors (including proximity switches) for the first time since 2008. As an upgraded product of the end switch (traditional mechanical contact type), the proximity sensor has the characteristics of long service life, reliable operation, high repeated positioning accuracy, no mechanical wear, no sparks, no noise, strong vibration resistance, sensitive response, small size, light weight, easy installation and adjustment, etc. It is widely used in the aircraft landing gear retraction system, cabin door system, reverse thrust system, rudder and balancing system, etc., as a limit, counting, positioning control and automatic protection link.

[0003] The magnetic core structure of the proximity sensor can be divided into coreless, cylindrical, E-type and can-shaped, etc. The existing proximity sensors mostly use can-shaped ferrite cores, which helps the proximity sensor's approach (level flip) distance to be far enough. However, the current aviation electromechanical system usually requires a proximity distance between 1mm and 4mm, and the requirement for long-distance detection is not high. For the proximity sensor that has been finalized using a can-shaped ferrite core, its approach distance is difficult to accurately adjust. Therefore, in view of the above problems, the present invention proposes a cylindrical proximity sensor whose approach distance can be accurately fine-tuned. Summary of the invention

[0004] Purpose of the Invention

[0005] Provided is a cylindrical proximity sensor suitable for the complex environment of an aviation electromechanical system, with a proximity distance that can be precisely fine-tuned.

[0006] Technical Solution

[0007] A cylindrical proximity sensor with a precisely fine-tunable proximity distance, characterized by comprising:

[0008] An end cover (1), a retaining ring (2), a bushing (3), a housing (4), a coil assembly (5), a cylindrical core (6), a coil sleeve (7), a coil cover (8), a wave spring (9), a conditioning circuit board (10), a mounting frame (11), a coil frame (12), and an enameled wire (13), wherein:

[0009] The coil assembly (5) is composed of a coil frame (12) and an enameled wire (13); a column is provided on the coil frame (12) for limiting the position of the coil sleeve (7) and the coil cover (8); the coil assembly (5), the coil sleeve (7) and the coil cover (8) are connected in sequence, the columnar iron core (6) is inserted into the coil assembly (5) from the bottom, and is screwed into the coil cover (8) by means of a thread to achieve distance adjustment and fixation;

[0010] The coil assembly (5), the cylindrical iron core (6), the coil sleeve (7) and the coil cover (8) form an iron core connecting ring assembly, which is placed in the shell (4) and glued to the shell (4) and the coil cover (8) to achieve wall fixing;

[0011] The bushing (3), the wave spring (9) and the retaining ring (2) are sequentially placed in the housing (4); a mounting groove is provided inside the housing (4) for mounting the retaining ring (2) to achieve pre-tightening of the sensitive structure of the sensor;

[0012] The mounting frame (11) is placed in the housing (4) and supported by the bushing (3). The mounting frame (11) has slots on both sides for positioning and adjusting the circuit board (10);

[0013] The coil frame (12), the coil sleeve (7), the coil cover (8) and the bushing (3) are all provided with lead holes for connecting the enameled wire (13) with the lead of the conditioning circuit board (10);

[0014] The end cover (1) and the mounting frame (11) press and condition the circuit board (10); the end cover (1) has a central opening for leading out the leads of the circuit board (10); and the end cover (1) and the housing (4) are connected by threads.

[0015] Furthermore, the housing (4) has a standard external thread, which can be fixed with a standard nut or directly installed at a target position;

[0016] A slot is formed on the top of the cylindrical iron core (6), and a slotted screwdriver can be used to adjust the relative position of the cylindrical iron core (6) inside the proximity sensor, thereby accurately fine-tuning the inductance output value of the sensor;

[0017] The bushing (3) and the mounting frame (11) have through holes in their centers, which facilitate the entry of a screwdriver to adjust the relative position of the cylindrical iron core (6).

[0018] The enameled wire (13) is wound into a coil by a cylindrical close winding method, the outermost layer is wrapped with a plastic film and tied with alkali-free glass fiber yarn, and after winding, it is dipped in varnish and cured;

[0019] Furthermore, the plastic film is specifically a polyimide film, which has excellent electrical properties and good wear resistance, arc resistance, and radiation resistance.

[0020] A method for assembling and adjusting a cylindrical proximity sensor with a precisely fine-tuned proximity distance comprises a target (14), a cylindrical proximity sensor (15), an anti-twist washer (16), a mounting plate (17), and a locking nut (18).

[0021] The installation method includes the following steps:

[0022] Step 1: The target (14) is fixedly mounted on the electromechanical system.

[0023] Step 2: The cylindrical proximity sensor (15) is fixed on the mounting plate (17) via an anti-twist washer (16) and a lock nut (18);

[0024] Step 3: adjusting the distance d between the proximity sensor (15) and the target (14) by adjusting the thread distance between the anti-loosening nut (18) and the proximity sensor (15);

[0025] Step 4: The mounting plate (17) is fixedly connected to the electromechanical system.

[0026] Furthermore, the target (14) is made of 15-5PH or 17-4PH to ensure the intensity of the eddy current generated on the target surface;

[0027] Furthermore, in order to fully utilize the eddy current effect, the diameter of the target (14) is not less than 1.8 times the diameter of the winding coil, and the thickness is not less than 2 mm;

[0028] The beneficial effects of this application are:

[0029] Compared with similar common models, the cylindrical proximity sensor of the present invention focuses on the design of the iron core and coil cover structure, and the inductance output value of the sensor is adjusted by the thread, so that the proximity distance between the sensor and the target can be adjusted. The vibration resistance of the sensor is improved by multiple damping structures such as wave springs and coil sleeves. The components used in the sensor are all made of common and easily accessible general materials. In general, the proximity distance of the proximity sensor of the present invention is easy to adjust, the shock resistance is strong, the structure is simple, and the cost is low. It is suitable for the landing gear retraction system, door system, reverse thrust system, rudder and balancing system of aviation airborne systems. In addition, the sensor of the present invention can also be used to build a non-contact speed sensor. Different from the traditional gear meshing speed sensor, the non-contact speed sensor with the present invention has a longer service life, higher working stability, better environmental adaptability, and can effectively measure the application scenarios that require speed measurement such as turning systems and engine systems, and has important engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of a cylindrical proximity sensor of the present invention.

[0031] Figure 2 It is a structural diagram of the cylindrical iron core of the present invention.

[0032] Figure 3 It is a schematic structural diagram of the coil assembly of the present invention.

[0033] Figure 4 It is a schematic diagram of the sensor installation method of the present invention.

[0034] The invention comprises: an end cover (1), a retaining ring (2), a bushing (3), a housing (4), a coil assembly (5), a cylindrical iron core (6), a coil sleeve (7), a coil cover (8), a wave spring (9), a conditioning circuit board (10), a mounting frame (11), a coil frame (12), an enameled wire (13), a target (14), a cylindrical proximity sensor (15), an anti-twist washer (16), a mounting plate (17), and a locking nut (18). DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the implementation of the present invention clearer, the technical scheme in the embodiment of the present invention will be described in more detail below in conjunction with the drawings in the embodiment of the present invention. In the drawings, the same or similar reference numerals throughout represent the same or similar originals or elements with the same or similar functions. The described embodiments are part of the embodiments of the present invention, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and intended to be used to explain the present invention, and should not be construed as limitations on the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The embodiments of the present invention are described in detail below in conjunction with the drawings.

[0036] Combine the following Figure 1 to Figure 4 The present invention is further described:

[0037] When the sensor is working, the working (voltage-stabilized) power supply enters from the lead wire led out from the end cover (1), and supplies power to the coil formed by the enameled wire (13) through the conditioning circuit board (10). At the same time, the coil and the capacitor at the conditioning circuit board (10) are connected in parallel to form an LC oscillation circuit to form a magnetic field. According to the eddy current effect, the target (14) and the cylindrical proximity sensor (15) produce mutual inductance. When the target (14) is in a distant state, the LC circuit is in an oscillation state; when the target (14) approaches, the coil magnetic resistance decreases, the inductance increases, and the oscillation amplitude decreases. When the target (14) approaches to a certain extent, the oscillation stops. The conditioning circuit performs signal detection, comparison, shaping, and amplification on the oscillation amplitude, and then outputs a switch signal to the aviation electromechanical system through the end cover (1). The approach distance is mainly determined by the coil parameters of the coil assembly (5) (the diameter of the coil frame (12), the number of turns and the number of turns of the enameled wire (13), etc.), the parameters of the conditioning circuit on the conditioning circuit board (10), and the distance between the cylindrical iron core (6) and the target (14). For a finalized product, the difficulty and workload of modifying the first two parameters are much greater than changing the distance between the cylindrical iron core (6) and the target (14).

[0038] When adjusting the proximity distance of the sensor, unscrew the end cover (1), pull the conditioning circuit board (10) out of the slot of the mounting frame (11), use a flat-blade screwdriver to twist the cylindrical iron core (6) through the through hole at the center of the mounting frame (11) and the bushing (3), and the iron core (6) and the coil cover (8) are connected by threads. The distance between the cylindrical iron core (6) and the target (14) can be adjusted through the threads, thereby changing the coil magnetic resistance and excitation inductance. Connect an oscilloscope to the conditioning circuit board (10), observe the inductance value of the coil or the amplitude of the oscillation waveform output after the conditioning circuit, and the sensor proximity distance can be accurately adjusted.

[0039] In terms of vibration resistance, when an acceleration signal acts on the sensor, the coil sleeve (7) and the wave spring (9) provide considerable damping, and most of the vibration energy is absorbed by the coil sleeve (7) and the wave spring (9), thereby greatly improving the vibration resistance of the sensor.

[0040] The cylindrical proximity sensor of the present invention has the advantages of adjustable proximity distance, strong vibration resistance, low cost, etc., and has important engineering application value.

[0041] The cylindrical iron core (6) and the coil cover (8) are connected by standard threads, and a slot is provided on the top of the cylindrical iron core (6), so that the relative position of the cylindrical iron core (6) inside the proximity sensor can be adjusted by a slotted screwdriver, thereby accurately fine-tuning the inductance output value of the sensor;

[0042] The bushing (3) and the mounting frame (11) have through holes in their centers, which facilitate the entry of a screwdriver to adjust the relative position of the cylindrical iron core (6);

[0043] The coil assembly (5) is composed of a coil frame (12) and an enameled wire (13), wherein the enameled wire (13) is wound into a coil by a cylindrical close winding method, and the outermost layer is wrapped with a polyimide film and tied with alkali-free glass fiber yarn, and then dipped in varnish and cured;

[0044] The coil frame (12) is provided with a column for positioning the coil sleeve (7) and the coil cover (8);

[0045] The coil sleeve (7) is made of rubber material and is installed between the coil assembly (5) and the coil cover (8) for protection and vibration reduction;

[0046] After the coil assembly (5), the cylindrical iron core (6), the coil sleeve (7) and the coil cover (8) are assembled, the assembly is placed in the bottom of the housing (4), and the housing (4) and the coil cover (8) are bonded using HY-914;

[0047] The coil frame (12), the coil sleeve (7), the coil cover (8) and the bushing (3) are all provided with lead holes for connecting the enameled wire (13) with the lead of the conditioning circuit board (10);

[0048] The wave spring (9) is installed between the retaining ring (2) and the bushing (3), and can also be installed between the bushing (3) and the coil cover (8). The number of the wave springs (9) can be adjusted according to the assembly conditions, so as to maintain a certain pre-pressure, eliminate the gap between components, and play a role in vibration reduction.

[0049] The housing (4) has an installation groove inside for installing the retaining ring (2). When designed, the top height of the installation groove is 1 to 3 mm lower than the total height of the coil assembly (5), coil sleeve (7), coil cover (8), bushing (3), wave spring (9), and retaining ring (2) at the contact part, so as to achieve the clamping of the overall structure inside the sensor and improve the vibration resistance;

[0050] The mounting frame (11) has slots on both sides for positioning and adjusting the circuit board (10). The mounting frame (11) is made of 30% glass fiber reinforced polyetheretherketone material to reduce weight while ensuring mechanical strength requirements.

[0051] The end cover (1) and the mounting frame (11) are pressed against the conditioning circuit board (10); a hole is opened in the center of the end cover (1) for leading out the leads of the conditioning circuit board (10); the end cover (1) and the housing (4) are connected by threads;

[0052] The housing (4) is provided with a standard external thread and can be fixed in cooperation with a standard nut, or can be directly installed at a target position.

[0053] It is understood by those skilled in the art that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as the general understanding of ordinary technicians in the field to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and unless defined as here, will not be interpreted with idealized or overly formal meanings. The specific implementation methods described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the present invention. Within the spirit and principle of the present invention, any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment of equivalent changes for application in other fields, but any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the technical solution content of the present invention, any modification, equivalent replacement, improvement, etc., made according to the technical essence of the present invention, should be included in the protection scope of the present invention.

Claims

1. A cylindrical proximity sensor with a precisely adjustable proximity distance, characterized in that: include: End cover, retaining ring, bushing, shell, coil assembly, cylindrical iron core, coil sleeve, coil cover, wave spring, conditioning circuit board, mounting frame, coil frame, enameled wire, the coil assembly is composed of a coil frame and enameled wire, the coil frame is provided with a column for limiting the position of the coil sleeve and the coil cover; the coil assembly, coil sleeve and coil cover are connected in sequence, the cylindrical iron core is inserted into the coil assembly from the bottom, and is screwed into the coil cover to achieve spacing adjustment and fixation; the coil assembly, cylindrical iron core, coil sleeve and coil cover form an iron core connecting ring assembly, which is placed in the shell, and the shell and The coil cover is fixed on the wall; the bushing, wave spring and retaining ring are placed in the shell in sequence, and an installation groove is opened inside the shell for installing the retaining ring to realize pre-tightening of the sensor sensitive structure; the mounting frame is placed in the shell and supported by the bushing, and slots are opened on both sides of the mounting frame for positioning the conditioning circuit board; lead holes are opened on the coil frame, coil sleeve, coil cover and bushing for connecting the enameled wire with the leads of the conditioning circuit board; the end cover and the mounting frame press the conditioning circuit board, and the center of the end cover has a hole for leading out the leads of the conditioning circuit board, and the end cover is connected to the shell by threads.

2. The sensor according to claim 1, characterized in that The housing is provided with a standard external thread, which is fixed in cooperation with a standard nut and can also be directly installed at a target position.

3. The sensor according to claim 2, characterized in that A slot is provided on the top of the cylindrical iron core, and a slotted screwdriver is used to adjust the relative position of the cylindrical iron core inside the proximity sensor, thereby precisely fine-tuning the inductance output value of the sensor.

4. The sensor according to claim 3, characterized in that The bushing and the mounting frame have through holes in their centers, which facilitate the entry of a screwdriver to adjust the relative position of the cylindrical iron core.

5. The sensor according to claim 4, characterized in that The enameled wire is wound into a coil by a cylindrical close winding method, the outermost layer is wrapped with a plastic film and tied with alkali-free glass fiber yarn, and after winding, it is dipped in paint and cured.

6. The sensor according to claim 5, characterized in that The plastic film is specifically a polyimide film.

7. The sensor installation method according to claim 6, characterized in that: The following steps are involved: Step 1: The target is fixedly mounted on the electromechanical system; The cylindrical proximity sensor in step 2 is fixed to the mounting plate by means of an anti-twist washer and a lock nut; Step 3: Adjust the distance d between the proximity sensor and the target by adjusting the distance between the anti-loosening nut and the proximity sensor thread; Step 4: Fix the mounting plate to the electromechanical system.

8. The adjustment method according to claim 7, characterized in that: The target is made of 15-5PH or 17-4PH to ensure the intensity of eddy current generated on the target surface.

9. The adjustment method according to claim 8, characterized in that: In order to make full use of the eddy current effect, the target diameter should be no less than 1.8 times the diameter of the winding coil and the thickness should be no less than 2 mm.

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