Onboard electromagnetic induction type rotational speed sensor and method for manufacturing same

Abstract

The application discloses an airborne electromagnetic induction type rotating speed sensor and a manufacturing method thereof, and comprises the following steps: preparing a magnetic steel, a pole shoe, a coil framework, a shell and a connector respectively; connecting the magnetic steel and the pole shoe by vacuum brazing, measuring the surface magnetism of the magnetic steel after the brazing is completed, magnetizing the magnetic steel if the surface magnetism decreases, bonding the coil framework on the magnetic steel and the pole shoe; winding a coil on the coil framework by using an enameled wire, connecting the enameled wire with a transition wire, and bonding the enameled wire and the transition wire on the magnetic steel to obtain a magneto-electric conversion assembly; fixing the magneto-electric conversion assembly in the shell by using segmented filling organic silica gel, and connecting the transition wire with the connector; fixing the connector on the shell by using rolling and locking, and magnetizing the sensor as a whole; compared with the prior art, the working reliability of the magneto-electric conversion assembly is ensured by vacuum brazing and segmented filling, and the consistency of the sensor is ensured by rolling and locking and overall magnetization.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and in particular, to a method for manufacturing an airborne electromagnetic induction speed sensor. Furthermore, this invention also relates to an airborne electromagnetic induction speed sensor employing the aforementioned method. Background Technology

[0002] Electromagnetic induction speed sensors are commonly used in aircraft engines to measure engine speed. This is because aircraft engines operate in harsh and extreme environments, and electromagnetic induction speed sensors still possess reliability, durability, and environmental adaptability that are difficult for other types of sensors to match even in extreme environments.

[0003] However, existing electromagnetic induction speed sensors have the following shortcomings: 1) Poor Inconsistency: Electromagnetic induction speed sensors are typically welded, fully sealed structures. Due to welding deformation, even sensors manufactured in the same batch can exhibit variations in output performance, resulting in poor consistency. For example, in a magnetoelectric dual-redundant speed sensor disclosed in Chinese utility model patent CN219456203U, the housing includes an outer shell and a fixed base. One end of the fixed base is connected to the outer shell, and the other end is connected to a connector. The fixed base and connector are laser-welded. One end of the fixed base is welded to the end face of the outer shell. Based on this design, the aforementioned shortcomings exist. 2) The pole shoes and magnets are prone to detachment: The connection between the pole shoes and magnets is usually achieved by bonding them with special magnetic adhesive and then magnetically attracting them. Due to structural limitations, the effective contact area between the two is small, only about 1 / 3 of the cross-sectional area of ​​the magnet. In the high-temperature and high-vibration environment of aero-engines, there is a risk that the pole shoes and magnets may detach, leading to unstable or even lost speed signals. Furthermore, the special magnetic adhesive can create an air gap between the magnet and the pole shoes that is difficult to control consistently, causing magnetic energy loss and affecting the sensor's output amplitude. For example, in a high-reliability environmentally adaptable magnetoelectric speed sensor for engines disclosed in Chinese Utility Model Patent CN212341238U, the iron core penetrates through the inner side of the cavity of the frame, and the magnet is fixed to the rear end of the iron core by strong magnetic attraction. The iron core and the frame are fixed with high-temperature resistant epoxy adhesive, and the inside of the housing is filled and potted with high-temperature resistant epoxy adhesive. Based on the above solution, the aforementioned shortcomings exist. Summary of the Invention

[0004] This invention provides an airborne electromagnetic induction speed sensor and its manufacturing method to solve the technical problems of poor consistency and easy separation of pole shoes and magnets in existing electromagnetic induction speed sensors.

[0005] According to one aspect of the present invention, a method for manufacturing an airborne electromagnetic induction speed sensor is provided, comprising the following steps: preparing a magnet, pole piece, coil frame, housing, and connector respectively; connecting the magnet and pole piece by vacuum brazing; measuring the surface magnetism of the magnet after brazing, and magnetizing the magnet if the surface magnetism decreases; then bonding the coil frame to the magnet and pole piece; winding a coil on the coil frame using enameled wire, connecting the enameled wire to an adapter wire, and bonding the enameled wire to the magnet to obtain a magnetoelectric conversion assembly; fixing the magnetoelectric conversion assembly in the housing by segmented potting silicone, and connecting the adapter wire to the connector; fixing the connector to the housing by rolling and locking, and magnetizing the sensor as a whole.

[0006] As a further improvement to the above technical solution: Further, the specific steps for segmented potting of silicone are as follows: place the magnetoelectric conversion component inside the housing, pour vacuum-mixed and degassed silicone into the housing under vacuum conditions until the silicone covers the magnet, and then pressurize the silicone to cure; cut the adapter cable to the preset position, use a soldering iron to solder the adapter cable and the connector terminals, and use heat shrink tubing to protect the solder joints between the adapter cable and the terminals; pour silicone into the housing under normal pressure until the silicone almost covers the terminals; embed the connector into the housing, invert the sensor and cure the silicone, and let it stand for a preset time.

[0007] Furthermore, the connector's insert end has a trapezoidal tooth structure.

[0008] Furthermore, the magnet is made of samarium-cobalt alloy, the pole piece is made of permalloy, the vacuum brazing filler metal is made of silver-copper alloy, and the welding temperature is 820℃-850℃.

[0009] Furthermore, the weld gap during vacuum brazing is 0.03mm-0.06mm.

[0010] Furthermore, the housing includes a closed end facing the test piece and an open end facing away from the test piece. The open end has a recessed receiving groove for accommodating the magnetoelectric conversion component. The thickness between the bottom of the receiving groove and the end face of the closed end is 0.2mm-0.5mm.

[0011] Furthermore, the parallelism between the bottom of the receiving tank and the end face of the closed end is not higher than 0.02 mm.

[0012] Furthermore, the specific steps for winding the coil are as follows: the coil frame is divided into a front winding area and a rear winding area along the pole shoe axis. In the front winding area, two wires are wound in parallel to output two signals simultaneously. In the rear winding area, a single wire is wound to output one signal. After winding, heat-resistant tape is used for protection. The front winding area is close to the device under test, and the rear winding area is far away from the device under test.

[0013] Furthermore, the enameled wire is connected to the adapter wire via soldering iron. The specific steps for bonding the enameled wire and the adapter wire to the magnet are as follows: first, wrap a layer of heat-resistant tape around the magnet as a base, and then use heat-resistant tape to fix the enameled wire, the adapter wire, and the solder joint between the enameled wire and the adapter wire to the magnet.

[0014] According to another aspect of the present invention, an airborne electromagnetic induction speed sensor is also provided, which employs the above-described airborne electromagnetic induction speed sensor manufacturing method.

[0015] The present invention has the following beneficial effects: The airborne electromagnetic induction speed sensor manufacturing method of the present invention first prepares a magnet, pole piece, coil frame, housing, and connector respectively; then, the magnet and pole piece are connected by vacuum brazing. Because vacuum brazing involves uniform heating followed by controlled slow cooling, the temperature gradient is greatly reduced, allowing sufficient time for the brazing filler metal layer to undergo micro-creep during solidification, releasing residual welding stress and effectively preventing the magnet from cracking after welding or during high-frequency vibrations in the airborne environment. Furthermore, in a high-vacuum environment, the melted brazing filler metal does not form pores or blind spots due to air entrainment, greatly improving performance. This process significantly improves the brazing rate between the magnet and the pole shoe end face, and also enhances the reliability of the connection. After brazing, the magnetic lines of force of the magnet can pass through the pole shoe more smoothly for focusing, thereby increasing the magnetic flux density, improving the output amplitude of the sensor, and achieving efficient magnetic circuit conduction. After brazing, the surface magnetism of the magnet is measured. If the surface magnetism decreases, the magnet is magnetized to eliminate the influence of high temperature on the magnetism of the magnet during vacuum brazing. Then, the coil frame is bonded to the magnet and the pole shoe. Next, the coil is wound on the coil frame using enameled wire, and then the enameled wire is connected to the adapter wire and bonded to the magnet. The process involves obtaining a magnetoelectric conversion component, then using segmented potting silicone to fix the component within the housing. This makes the internal structure of the sensor more stable and enhances its ability to withstand vibration stress during operation. The adapter cable is then connected to the connector. Since the connector requires frequent insertion and removal during maintenance and installation, it experiences significant tensile stress. Segmented potting effectively dissipates this stress within the segmented silicone layers, reducing or even preventing its transmission to the coil leads, thus effectively protecting the coil. Finally, a rolling lock is used to fix the connector to the housing. The housing has no welded joints, ensuring good sensor consistency. The sensor is then magnetized as a whole, further improving consistency. In this solution, vacuum brazing ensures the connection strength between the pole shoes and magnets, as well as efficient magnetic circuit conduction. Segmented potting ensures the reliable operation of the magnetoelectric conversion component. The combination of these two methods achieves long-term stability of the sensor's overall magnetic circuit under extreme environments of strong airborne vibration and wide temperature differences, significantly improving the sensor's lifespan and reliability. Furthermore, the rolling lock fixing of the connector and overall magnetization ensure sensor consistency, making this solution highly practical and suitable for widespread promotion and application.

[0016] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1This is a flowchart illustrating the steps of a preferred embodiment of the manufacturing method of an airborne electromagnetic induction speed sensor of the present invention. Figure 2 This is a cross-sectional schematic diagram of an airborne electromagnetic induction speed sensor according to a preferred embodiment of the present invention; Figure 3 This is a partial structural schematic diagram of an airborne electromagnetic induction speed sensor according to a preferred embodiment of the present invention.

[0018] Legend: 1. Magnet; 2. Pole shoe; 3. Coil frame; 4. Adapter cable; 5. Enamelled wire; 6. Housing; 7. Silicone silicone; 8. Connector. Detailed Implementation

[0019] The following description provides specific application scenarios and requirements for this specification, intended to enable those skilled in the art to make and use the contents of this specification. Various partial modifications to the disclosed embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments and applications without departing from the spirit and scope of this specification.

[0020] Considering the following description, these and other features of this specification, as well as the operation and function of the related components of the structure, and the economy of assembly and manufacture of the parts, can be significantly improved. All of these form part of this specification with reference to the accompanying drawings. However, it should be clearly understood that the drawings are for illustrative and descriptive purposes only and are not intended to limit the scope of this specification. It should also be understood that the drawings are not drawn to scale.

[0021] like Figure 1 and Figure 2 As shown, the airborne electromagnetic induction type speed sensor manufacturing method of this embodiment includes the following steps: S1: Prepare magnet 1, pole shoe 2, coil frame 3, housing 6 and connector 8 respectively; S2: Vacuum brazing is used to connect magnet 1 and pole shoe 2. After the brazing is completed, the surface magnetism of magnet 1 is measured. If the surface magnetism decreases, magnet 1 is magnetized. Then the coil frame 3 is glued to magnet 1 and pole shoe 2. S3: Use enameled wire 5 to wind a coil on the coil frame 3, then connect the enameled wire 5 to the adapter wire 4, and then attach the enameled wire 5 and the adapter wire 4 to the magnet 1 to obtain the magnetoelectric conversion assembly. S4: The magnetoelectric conversion component is fixed inside the housing 6 by using segmented potting silicone 7, and the adapter cable 4 is connected to the connector 8; S5: The connector 8 is fixed to the housing 6 by rolling and locking, and the sensor is magnetized as a whole.

[0022] like Figure 1 andFigure 2 As shown, specifically, the airborne electromagnetic induction speed sensor manufacturing method of this embodiment first prepares the magnet 1, pole shoe 2, coil frame 3, housing 6, and connector 8 respectively; then, the magnet 1 and pole shoe 2 are connected by vacuum brazing. Because vacuum brazing involves uniform heating followed by controlled slow cooling, the temperature gradient is greatly reduced, allowing sufficient time for the brazing filler layer to undergo micro-creep during solidification, releasing residual welding stress and effectively preventing the magnet 1 from cracking after welding or during high-frequency vibrations in the airborne environment. Furthermore, in a high vacuum environment, the melted brazing filler will not form pores due to air entrainment. The blind zone significantly improves the brazing rate of the end face connection between magnet 1 and pole shoe 2, and the reliability of the connection is also significantly enhanced. After welding, the magnetic lines of force of magnet 1 can pass through pole shoe 2 more smoothly for focusing, thereby increasing the magnetic flux density, increasing the output amplitude of the sensor, and realizing efficient magnetic circuit conduction. After the brazing is completed, the surface magnetism of magnet 1 is measured. If the surface magnetism decreases, magnet 1 is magnetized to eliminate the influence of high temperature on the magnetism of magnet 1 during vacuum brazing. Then, the coil frame 3 is bonded to magnet 1 and pole shoe 2. Then, the enameled wire 5 is used to wind the coil on the coil frame 3, and then the enameled wire 5 is connected to the adapter wire 4, and the enameled wire 5 and the adapter wire 4 are connected to the adapter wire 4. The adapter cable 4 is bonded to the magnet 1 to obtain the magnetoelectric conversion assembly. Then, segmented potting silicone 7 is used to fix the magnetoelectric conversion assembly inside the housing 6, making the internal structure of the sensor more stable and stronger in withstanding vibration stress during operation. This connects the adapter cable 4 to the connector 8. Since the connector 8 requires frequent insertion and removal during maintenance and installation, it experiences significant tensile stress. Segmented potting effectively dissipates this tensile stress within the segmented silicone layers, reducing or even preventing its transmission to the coil leads, thus effectively protecting the coil. Finally, a rolling lock is used to fix the connector 8 to the housing 6. With no welded joints, the sensor exhibits excellent consistency, and the overall magnetization of the sensor further enhances this consistency. In this design, vacuum brazing ensures the connection strength between the pole shoe 2 and the magnet 1, as well as the efficient conduction of the magnetic circuit. Segmented potting ensures the reliable operation of the magnetoelectric conversion component. The combination of these two methods achieves long-term stability of the sensor's overall magnetic circuit under extreme environments of strong airborne vibration and wide temperature differences, significantly improving the sensor's lifespan and reliability. Furthermore, the rolling and locking of the connector 8 and the overall magnetization ensure the sensor's consistency, making it highly practical and suitable for widespread promotion and application.

[0023] Optionally, the surfaces of magnet 1 and pole shoe 2 are nickel-plated to improve the wettability of the brazing filler metal.

[0024] Optionally, epoxy resin adhesive is used to bond the coil frame 3 to the pole shoe 2 and the magnet 1.

[0025] In this embodiment, the magnet 1 is made of samarium-cobalt alloy, the pole piece 2 is made of permalloy, and the vacuum brazing filler metal is made of silver-copper alloy. The welding temperature is 820℃-850℃. Specifically, the Curie temperature of samarium-cobalt alloy is approximately 800℃, and the Curie temperature of permalloy is approximately 980℃. By using samarium-cobalt alloy to prepare the magnet 1 and permalloy to prepare the pole piece 2, and controlling the welding temperature to 820℃-850℃, the influence of high temperature on the magnet 1's magnetism during vacuum brazing is reduced. Simultaneously, the filler metal is allowed to melt completely, possessing sufficient fluidity to fill the weld gap. Furthermore, the use of silver-copper alloy to prepare the vacuum brazing filler metal improves its wettability during vacuum brazing, thus enhancing the welding quality.

[0026] Furthermore, in step S2, the weld gap during vacuum brazing is 0.03mm-0.06mm. Specifically, when the weld gap during vacuum brazing is between 0.03mm and 0.06mm, the connection strength between the pole piece 2 and the magnet 1 after vacuum brazing is high, and there are no welding defects. When the weld gap during vacuum brazing is less than 0.03mm, the brazing filler metal cannot flow smoothly into the weld gap, and welding defects such as local porosity and slag inclusions are prone to occur. When the weld gap during vacuum brazing is greater than 0.06mm, the capillary effect of the brazing filler metal is significantly weakened, and the brazing filler metal will be lost under the action of gravity and surface tension, resulting in low connection strength between the pole piece 2 and the magnet 1 after vacuum brazing.

[0027] Further, in step S3, the specific steps for winding the coil are as follows: the coil frame 3 is divided into a front winding area and a rear winding area along the axial direction of the pole shoe 2. In the front winding area, two wires are wound in parallel to output two signals simultaneously. In the rear winding area, a single wire is wound to output one signal. After winding, heat-resistant tape is used for protection. The front winding area is close to the device under test, and the rear winding area is far away from the device under test.

[0028] Specifically, since the rear winding area is far from the measured object, the number of turns is increased by single-wire winding to improve the output amplitude. Two signals are output through the front winding area and one signal through the rear winding area, so that the sensor can output three independent speed signals to improve the reliability of speed measurement.

[0029] In this embodiment, the enameled wire 5 is connected to the adapter wire 4 by soldering with a soldering iron. In step S3, the specific steps for bonding the enameled wire 5 and the adapter wire 4 to the magnet 1 are as follows: first, wrap a layer of heat-resistant tape around the magnet 1 as a base, and then use heat-resistant tape to fix the enameled wire 5, the adapter wire 4, and the solder joint between the enameled wire 5 and the adapter wire 4 to the magnet 1.

[0030] Specifically, the enameled wire 5 and the adapter wire 4 are secured with heat-resistant tape to ensure reliable operation in extreme environments.

[0031] Optionally, adapter cable 4 is an insulated copper wire.

[0032] Optionally, the heat-resistant tape is PI tape.

[0033] Optionally, the exterior of the housing 6 is provided with a threaded connection for installation, and the rear end of the threaded connection is provided with a sealing groove.

[0034] Further, step S4, the specific steps for segmented potting of silicone 7 are as follows: S41: Place the magnetoelectric conversion component inside the housing 6, and pour vacuum-mixed and degassed silicone 7 into the housing 6 under vacuum environment until the silicone 7 covers the magnet 1, and then press back to cure the silicone 7. S42: Cut the adapter cable 4 to the preset position, use a soldering iron to solder the adapter cable 4 to the terminal of the connector 8, and use heat shrink tubing to protect the solder joint between the adapter cable 4 and the terminal. S43: Pour silicone 7 into housing 6 under normal pressure until silicone 7 is close to covering the wiring terminals. S44: Embed the connector 8 into the housing 6, invert the sensor and cure the silicone 7, and let it stand for a preset time.

[0035] Specifically, vacuum potting can fill the microscopic gaps between the enameled wires 5 inside the coil, preventing dielectric breakdown of the coil under high-frequency alternating electromagnetic fields or high temperatures, and can significantly reduce the bubble problem of silicone 7, thereby effectively reducing the expansion of the colloid, improving the stability of the structure, and ensuring the reliable operation of the magnetoelectric conversion component in extreme environments. Vacuum potting is performed first, and then the adapter wire 4 is soldered to the terminal of the connector 8 to avoid the terminal of the connector 8 interfering with the potting of silicone 7. Heat shrink tubing is used to ensure the reliable operation of the adapter wire 4 and the terminal in extreme environments. After the colloid is potted at normal pressure, the housing 6 is inverted to glue the connector and protect the coil leads. At this time, the tiny bubbles inside the colloid will naturally be discharged upward due to buoyancy, while the colloid will naturally accumulate downward under the action of gravity, filling the gap between the connector 8 and the housing 6 and ensuring the sealing of the sensor.

[0036] Optionally, the preset settling time is 24 hours.

[0037] In this embodiment, the insert end of the connector 8 has a trapezoidal tooth structure. Specifically, the trapezoidal tooth structure greatly increases the bonding area between the connector 8 and the silicone 7, thereby improving the bonding strength.

[0038] In this embodiment, the housing 6 includes a closed end facing the measured object and an open end facing away from the measured object. The open end has a recessed receiving groove for accommodating the magnetoelectric conversion component. The thickness between the bottom of the receiving groove and the end face of the closed end is 0.2mm-0.5mm. Specifically, the housing 6 is a semi-enclosed structure, machined, with high processing precision and good consistency. The receiving groove accommodates the magnetoelectric conversion component, and the connector 8 is rolled and locked in place, so that there are no welded joints on the housing 6. By keeping the thickness between the bottom of the receiving groove and the end face of the closed end at 0.2mm-0.5mm, the overall structural strength and electromagnetic performance of the sensor are guaranteed. When the thickness between the bottom of the receiving groove and the end face of the closed end is less than 0.2mm, the structural strength of the sensor is insufficient, and it is prone to bulging and deformation under air pressure. When the thickness between the bottom of the receiving groove and the end face of the closed end is greater than 0.5mm, the magnetic resistance in the magnetic circuit is increased, resulting in a weakening of the sensor's output performance.

[0039] In this embodiment, the parallelism between the bottom of the receiving groove and the end face of the closed end is no higher than 0.02 mm. Specifically, if the parallelism between the bottom of the receiving groove and the end face of the closed end is higher than 0.02 mm, the magnetoelectric conversion component inside the sensor will tilt after assembly, causing the magnetic field to tilt accordingly, resulting in distortion of the output signal or asymmetry of the waveform. Therefore, when the parallelism between the bottom of the receiving groove and the end face of the closed end is no higher than 0.02 mm, the output signal is stable and reliable.

[0040] like Figure 2 As shown, the airborne electromagnetic induction speed sensor of this embodiment adopts the above-described airborne electromagnetic induction speed sensor manufacturing method. Specifically, by using the above-described airborne electromagnetic induction speed sensor manufacturing method, an airborne electromagnetic induction speed sensor is obtained, ensuring that the connection between the magnet 1 and the pole shoe 2 is reliable under extreme environments, the speed signal output is stable, and the mass-produced sensors have good consistency, strong practicality, and are suitable for widespread promotion and application.

[0041] like Figure 2 and Figure 3 As shown, in this embodiment, the airborne electromagnetic induction speed sensor includes a magnet 1, a pole shoe 2, a coil frame 3, an enameled wire 5, an adapter wire 4, a housing 6, silicone rubber 7, and a connector 8. The magnet 1 is welded to the pole shoe 2, the coil frame 3 is bonded to the magnet 1 and the pole shoe 2, the enameled wire 5 is wound around the outside of the coil, the adapter wire 4 is welded to the enameled wire 5, the silicone rubber 7 is potted inside the housing 6, the connector 8 is glued to the silicone rubber 7, and then rolled and locked to the housing 6. The terminals of the connector 8 are connected to the adapter wire 4.

[0042] In summary, after reading the detailed disclosure of this specification, those skilled in the art will understand that the foregoing detailed disclosure is presented by way of example only and is not restrictive. Although not explicitly stated herein, those skilled in the art will understand that this specification requires various reasonable changes, improvements, and modifications to the embodiments. These changes, improvements, and modifications are intended to be made by this specification and are within the spirit and scope of the exemplary embodiments described herein.

[0043] It should be understood that in the foregoing description of the embodiments in this specification, various features are combined in a single embodiment, drawing, or description for the purpose of simplifying the description and aiding in the understanding of a feature. However, this does not mean that the combination of these features is necessary, and those skilled in the art may readily identify some of the devices as separate embodiments when reading this specification. That is, the embodiments in this specification can also be understood as an integration of multiple secondary embodiments. It is also valid when each secondary embodiment contains fewer than all the features of a single foregoing disclosed embodiment.

[0044] Finally, it should be understood that the embodiments disclosed in this specification are illustrative of the principles of the embodiments described in this specification. Other modified embodiments are also within the scope of this specification. Therefore, the embodiments disclosed in this specification are merely examples and not limitations. Those skilled in the art can implement the applications in this specification using alternative configurations based on the embodiments in this specification. Therefore, the embodiments in this specification are not limited to the embodiments precisely described in the applications.

Claims

1. A method for manufacturing an airborne electromagnetic induction type speed sensor, characterized in that, Includes the following steps: Magnet (1), pole piece (2), coil frame (3), housing (6) and connector (8) are prepared respectively; Vacuum brazing is used to connect the magnet (1) and the pole shoe (2). After the brazing is completed, the surface magnetism of the magnet (1) is measured. If the surface magnetism decreases, the magnet (1) is magnetized. Then the coil frame (3) is glued to the magnet (1) and the pole shoe (2). A coil is wound on the coil frame (3) using enameled wire (5), and then the enameled wire (5) is connected to the adapter wire (4), and the enameled wire (5) and the adapter wire (4) are glued to the magnet (1) to obtain a magnetoelectric conversion assembly. The magnetoelectric conversion assembly is fixed inside the housing (6) by segmented potting silicone (7), and the adapter cable (4) is connected to the connector (8); The connector (8) is fixed to the housing (6) by rolling and locking, and the sensor is magnetized as a whole.

2. The method for manufacturing an airborne electromagnetic induction speed sensor according to claim 1, characterized in that, The specific steps for segmented potting of silicone (7) are as follows: The magnetoelectric conversion component is placed inside the housing (6), and vacuum-mixed and degassed silicone (7) is poured into the housing (6) under vacuum environment until the silicone (7) covers the magnet (1), and then the silicone (7) is cured by back pressure. Cut the adapter cable (4) to the preset position, use a soldering iron to solder the adapter cable (4) and the connector (8) terminals, and use heat shrink tubing to protect the solder joints between the adapter cable (4) and the terminals; Under normal pressure, silicone (7) is poured into the housing (6) until silicone (7) almost covers the wiring terminals; Embed the connector (8) into the housing (6), invert the sensor and cure the silicone (7), and let it stand for a preset time.

3. The method for manufacturing an airborne electromagnetic induction speed sensor according to claim 2, characterized in that, The insertion end of the connector (8) has a trapezoidal tooth structure.

4. The method for manufacturing an airborne electromagnetic induction speed sensor according to claim 1, characterized in that, The magnet (1) is made of samarium cobalt alloy, the pole shoe (2) is made of permalloy, the vacuum brazing filler metal is made of silver-copper alloy, and the welding temperature is 820℃-850℃.

5. The method for manufacturing an airborne electromagnetic induction speed sensor according to claim 1, characterized in that, The weld gap during vacuum brazing is 0.03mm-0.06mm.

6. The method for manufacturing an airborne electromagnetic induction speed sensor according to any one of claims 1-5, characterized in that, The housing (6) includes a closed end facing the test piece and an open end facing away from the test piece. The open end has a recessed receiving groove for accommodating the magnetoelectric conversion component. The thickness between the bottom of the receiving groove and the end face of the closed end is 0.2mm-0.5mm.

7. The method for manufacturing an airborne electromagnetic induction speed sensor according to claim 6, characterized in that, The parallelism between the bottom of the receiving tank and the end face of the closed end shall not exceed 0.02mm.

8. The method for manufacturing an airborne electromagnetic induction speed sensor according to any one of claims 1-5, characterized in that, The specific steps for winding a coil are as follows: The coil frame (3) is divided into a front winding area and a rear winding area along the pole shoe (2) axis. In the front winding area, two wires are wound in parallel to output two signals at the same time. In the rear winding area, a single wire is wound to output one signal. After the winding is completed, heat-resistant tape is used to protect them. The front winding area is close to the test piece, and the rear winding area is far away from the test piece.

9. The method for manufacturing an airborne electromagnetic induction speed sensor according to any one of claims 1-5, characterized in that, The enameled wire (5) is connected to the adapter wire (4) by soldering with a soldering iron. The specific steps for bonding the enameled wire (5) and the adapter wire (4) to the magnet (1) are as follows: First, wrap a layer of heat-resistant tape around the magnet (1) as a base, and then use heat-resistant tape to fix the enameled wire (5), the adapter wire (4), and the solder joint between the enameled wire (5) and the adapter wire (4) onto the magnet (1).

10. An airborne electromagnetic induction type speed sensor, characterized in that, The method for manufacturing an airborne electromagnetic induction speed sensor according to any one of claims 1-9.

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