Rotating speed sensor based on Hall effect

Abstract

The utility model relates to a rotating speed sensor based on a Hall effect, which belongs to the technical field of rotating speed sensors and comprises a sensor support, a protective cover, a circuit board assembly and a Hall element. One side of the protective cover is provided with a protective cover gluing groove used for gluing and bonding a sensor support and a protective cover Hall installation groove used for installing a Hall element, and the protective cover Hall installation groove is filled with silicone grease pouring sealant. The rotating speed sensor based on the Hall effect is strong in anti-electromagnetic interference capability, capable of realizing more stable and reliable output by detecting magnetic field change and converting the magnetic field change into an electric signal for output, small in size, sensitive to the magnetic field, wide in detection frequency and high in output precision; pulses generated by magnetic field changes can be instantly detected and converted into electric signals to be output, the signal response is fast, and the sensitivity of a vehicle control system is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of rotational speed sensors, and particularly refers to a rotational speed sensor based on the Hall effect. Background Art

[0002] With the increasing automation of automobiles, the application of microelectronic integrated circuits is more and more, and it is more and more affected by electromagnetic interference. Especially for high-power headlights, air-conditioning motors, windshield wiper motors, etc., surge currents will be generated when they are switched on and off, causing arcs at the mechanical switch contacts and generating large electromagnetic interference signals to the circuit. In response to the interference of electromagnetic waves on integrated circuits, there are generally problems in the market such as unclear output waveforms, back-off, and low precision of the motor in the automotive ECU control, resulting in problems such as reduced comfort for vehicle drivers or the vehicle display not turning off. At the same time, the existing technology in the market obtains the rotational speed of the generator by detecting the tachometric generator signal. The connection method of the tachometric generator signal P terminal is generally divided into a threaded connection or a soldering connection of two connecting pieces. These two connection methods have the risk of P terminal connection failure or virtual connection due to external reasons such as vibration, thermal and cold shock, and harsh climate conditions. When the connection is disconnected or virtually connected, it will ultimately lead to abnormal power generation of the generator, affecting the driver's experience and use.

[0003] The rotational speed of the generator is one of the main detection indicators of the automotive alternator. Its main function is to detect and output the rotational speed through the regulator on the generator, and control the switching of the vehicle display and fuel injector. When the detection and output of the generator rotational speed are inaccurate or affected by electromagnetic interference, problems such as the vehicle display not turning off, fuel injection compensation not working, and abnormal power generation of the generator will occur.

[0004] The existing generator rotational speed mainly relies on the regulator to detect the tachometric generator signal and then transmit it to the ECU. After receiving the rotational speed signal, the ECU then transmits it outward to control the actions of other devices. Therefore, the quality of the detection and output of the generator rotational speed directly affects the quality of the automotive brand, the satisfaction evaluation of end-users, and their use.

[0005] In an automotive generator, the regulator mainly detects the rotational speed signal through an integrated electronic circuit. The integrated circuit is susceptible to electromagnetic interference, and this problem is difficult to improve due to various reasons such as space limitations. After being interfered, it will cause the regulator to detect and output inaccurate waveforms of the rotational speed, resulting in problems such as abnormal power generation of the generator.

[0006] In addition to the poor anti-electromagnetic interference ability mentioned above, the detection of the automobile generator speed signal is also affected by reasons such as unreliable connection methods. The automobile generator speed signal terminal is generally connected to the rectifier through the generator stator line, and the rectifier is then connected to the regulator. After the generator rotor rotates, the regulator detects the phase signal P terminal signal to realize the transmission and output of the speed. Because the generator will be in a long-term working state, under the influence of high-frequency vibration and harsh conditions of hot and cold shock, the P-terminal connection between the regulator and the rectifier will be loose or vibrated. Risks such as breakage will affect the detection and output of the speed signal, which will directly affect the use of automobile-related equipment and the use of buyers. Utility Model Content

[0007] The utility model aims to solve the above technical problems and provides a rotation speed sensor based on the Hall effect.

[0008] In order to solve the above technical problems, the technical solution provided by the utility model is:

[0009] A speed sensor based on the Hall effect, comprising a sensor bracket, a protective cover, a circuit board assembly and a Hall element.

[0010] One side of the protective cover is provided with a protective cover gluing groove for gluing the sensor bracket and a protective cover Hall installation groove for installing the Hall element, and the protective cover Hall installation groove is filled with silicone grease potting glue;

[0011] The Hall element is connected to the circuit board assembly;

[0012] The sensor bracket is provided with two boss mounting posts, the circuit board assembly is provided with mounting holes used in conjunction with the boss mounting posts, the sensor bracket is provided with an insert pin, and the circuit board assembly is provided with an insert pin welding hole for welding the insert pin.

[0013] Preferably, resistors and capacitors are installed on the circuit board assembly.

[0014] Preferably, the Hall elements are arranged in three groups, and the end of the Hall installation slot of the protective cover close to the sensor bracket is a bell mouth of the protective cover.

[0015] Preferably, a sensor mounting protrusion that matches the gluing groove of the protective cover is installed on the side of the sensor bracket close to the protective cover.

[0016] Preferably, a pin is installed on the sensor bracket.

[0017] Preferably, the protective cover is provided with protective cover reinforcement ribs.

[0018] Preferably, a long arc mounting hole is provided on the sensor bracket, and two sides of the long arc mounting hole are chamfered, and a plug buckle is installed on the sensor bracket.

[0019] Preferably, the side of the sensor bracket away from the plug snap is a semi-circular arc structure, and a groove is formed on the sensor bracket and a groove reinforcing rib is installed in the groove.

[0020] After adopting the above structure, the utility model has the following advantages:

[0021] 1. The rotational speed sensor based on the Hall effect of the utility model has strong anti-electromagnetic interference ability. By detecting the change of the magnetic field and converting it into an electrical signal output, it can achieve more stable and reliable output. It has a small volume, is sensitive to the magnetic field, has a wide detection frequency, and high output accuracy. When the generator rotates, the pulse generated by the magnetic field change can be instantaneously detected and converted into an electrical signal output, with a fast response to the signal, improving the sensitivity of the vehicle control system; the structure is simple, and through magnetic field induction detection and output, it avoids the risk brought by the unreliable connection of the conventional P-terminal signal, can adapt to harsh working environments, accurately detect the change of the rotational speed, and improve the service life of the product;

[0022] 2. The rotational speed sensor of the utility model uses a combined structure of a circuit board assembly and a Hall element. The circuit board assembly increases filtering capacitors and resistors, which can improve the service life of the product while meeting the requirements of different motor functions, and is resistant to vibration, salt spray and other harsh environments; two circular arc installation areas are designed in the structure, and the installation position can rotate around the motor shaft, and the sensor position can be adjusted according to different motors and working conditions, meeting the use of generators of different models, with high versatility.

[0023] 3. Two snap structures are designed on both sides of the plug, and a 6-pin staggered and circuitous structure is designed inside the plug to meet the fixation of the plug-in, improving the connection reliability; the sensor bracket is designed with a semi-circular arc structure, and the semi-circular arc structure is assembled with the motor end cover to ensure accurate positioning of the sensor. A groove structure is designed between the Hall installation groove of the protective cover and the semi-circular arc structure, and the groove structure can be stuck on the end cover to limit the radial freedom of the sensor and improve the installation accuracy of the sensor;

[0024] 4. The root of the Hall installation groove of the protective cover is designed with a structure that is narrow at the bottom and wide at the top, which is convenient for the installation of the Hall device and for applying glue, and improves the strength of the protective cover.

[0025] The above summary is only for the purpose of the specification and is not intended to be limiting in any way. In addition to the above-described illustrative aspects, embodiments and features, further aspects, embodiments and features of the utility model will be readily apparent by reference to the drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 This is an explosion diagram of the utility model;

[0028] Figure 2 Schematic diagram of this practical product;

[0029] Figure 3 This is the practical Hall principle diagram;

[0030] Figure 4 This is a schematic diagram of the practical Hall component;

[0031] Figure 5 It is a cross-sectional schematic diagram of the utility model;

[0032] Figure 6 It is a schematic diagram of the protective cover of the utility model.

[0033] As shown in the figure: 1. Protective cover, 2. Circuit board assembly, 3. Hall element, 4. Sensor bracket, 11. Protective cover Hall mounting slot, 12. Protective cover reinforcement rib, 13. Protective cover bell mouth, 14. Protective cover glue slot, 21. Resistor, 22. Pin welding hole, 23. Capacitor, 41. Boss mounting column, 42. Pin, 43. Sensor mounting protrusion, 44. Pin, 45. Long arc mounting hole, 46. Mounting hole chamfer, 47. Plug inverted, 48. Semi-circular arc structure, 49. Groove structure, 491. Groove reinforcement rib. DETAILED DESCRIPTION

[0034] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0035] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0036] The following further elaborates on the present utility model in conjunction with the full text.

[0037] Combined with the attached Figures 1 - 6 , a rotational speed sensor based on the Hall effect includes a sensor bracket 4, a protective cover 1, a circuit board assembly 2, and a Hall element 3. One side of the protective cover 1 is provided with a protective cover glue injection groove 14 for gluing and bonding the sensor bracket 4 and a protective cover Hall installation groove 11 for installing the Hall element 3, and the protective cover Hall installation groove 11 is filled with silicone grease potting glue; the Hall element 3 is connected to the circuit board assembly 2. On the side of the sensor bracket 4 close to the protective cover 1, there is a sensor installation protrusion 43 that cooperates with the protective cover glue injection groove 14. Two boss mounting posts 41 are installed on the sensor bracket 4. Mounting holes are provided on the circuit board assembly 2 for cooperating with the boss mounting posts 41. A pin 44 is installed on the sensor bracket 4, and a pin welding hole 22 for welding the pin 44 is provided on the circuit board assembly 2.

[0038] When the present utility model is specifically implemented, as Figure 1 , Figure 2 and Figure 4 shown, components such as a resistor 21 and a capacitor 23 are provided on the circuit board assembly 2, which are protective components to improve the electrical protection and filtering capabilities of the product. Three Hall elements 3 are provided, and each Hall element 3 has three pins respectively defined as GND, VDD, and OUT, which are welded and fixed to the corresponding welding hole positions on the circuit board assembly 2 respectively. The position of the Hall element 3 can be controlled according to the actual working conditions by cutting the length of the Hall element pins to control the position of the Hall element 3 relative to the circuit board assembly 2 to achieve the detection of the magnetic field. After forming the Hall assembly, it is positioned and assembled through two mounting holes on the Hall assembly and two boss mounting posts 43 provided on the sensor bracket 4. After assembly, the Hall assembly and the sensor bracket 4 are heat-melted and fixed through the boss mounting posts 43. The plug insert provided inside the sensor bracket 4 is then welded and fixed to the corresponding six pin welding holes 22 of the Hall assembly to improve the anti-vibration performance of the product. After welding, the inside of the sensor bracket 4 is filled with jelly potting glue to protect the solder joints from corrosion. The protective cover Hall installation groove 11 of the Hall protective cover 1 is filled with silicone rubber material, and bonding sealant is applied to the protective cover glue injection groove 14 of the protective cover 1 and bonded and assembled with the sensor installation protrusion 43 of the sensor bracket 4. Finally, it is tested, cured, and packaged.

[0039] The Hall element 3 is provided in three groups. One end of the protective cover Hall installation groove 11 close to the sensor bracket 4 is a protective cover flared mouth 13. The protective cover 1 is designed with three independent long oval arc-shaped protective cover Hall installation grooves 11, and the entrance is in a flared shape. The protective cover 1 is also designed with a roundabout protective cover glue injection groove for gluing and bonding the sensor bracket 4 to avoid problems such as internal electronic components getting water and short-circuiting.

[0040] When the present utility model is specifically implemented, as Figure 3 shown, three Hall elements 3 are provided. Each Hall element 3 has 3 pins, and the pin definitions are GND, VDD, and OUT respectively. Specifically, R1, R2, and R3 are resistors 20R 1206. The 1st pins of the three Hall elements 3 in the Hall schematic diagram are connected to the 2nd pin of the plug in a common line and collinearly. The 1st pin of the plug is grounded. C1, C2, and C3 are connected in parallel between the 1st pin of the plug and the common line of the 1st pins of the three Hall elements 3. The 2nd pins of the three Hall elements 3 are grounded. The 3rd pins of the three Hall elements 3 are respectively connected to one ends of R1, R2, and R3. The other end of R1 is connected to the 3rd pin of the plug, one end of C4, and one end of C5, and the other ends of C4 and C5 are connected to the ground. The other end of R2 is connected to the 4th pin of the plug, one end of C6, and one end of C7, and the other ends of C6 and C7 are connected to the ground. The other end of R3 is connected to the 5th pin of the plug, one end of C8, and one end of C9, and the other ends of C8 and C9 are connected to the ground. The magnetic field signal is converted into an electrical signal by 3 Hall sensors. The 3rd pin of the Hall element 3 is an open-drain output. When in use, an external pull-up resistor is required. When the S pole of the magnetic field approaches the sensor, the 3rd pin of the Hall element 3 outputs a low level. When the N pole of the magnetic field approaches the sensor or no magnetic field approaches the sensor, the 3rd pin of the Hall element 3 outputs a high level. During the rotation of the generator rotor, the N and S poles of the magnetic field approach the Hall sensor alternately, and the level on the 3rd pin of the Hall element 3 undergoes a periodic high-low conversion. By the frequency of the square wave output from the 3rd pin and combined with the number of rotor pole pairs, it can be immediately converted and output as the rotational speed of the generator. At the same time, 3 Hall sensors are used on one motor. According to the phase difference of the square waves output by the 3 Hall elements 3, the current position of the rotor can be immediately determined, improving the sensitivity of the motor.

[0041] Specifically, a protective cover reinforcing rib 12 is installed on the protective cover 1. The inner surface of the protective cover 1 is designed with radial protective cover reinforcing ribs 12, connecting each side of the protective cover 1 to improve the anti-deformation ability of the protective cover 1.

[0042] When the present utility model is specifically implemented, as Figure 1 and Figure 2As shown, a long arc mounting hole 45 is provided on the sensor bracket 4, and both sides of the long arc mounting hole 45 are mounting hole chamfers 46, a plug buckle 47 is installed on the sensor bracket 4, and the side of the sensor bracket 4 away from the plug buckle 47 is a semi-circular arc structure 48, a groove 49 is provided on the sensor bracket 4, and a groove reinforcement rib 491 is installed in the groove 49, and the Hall sensor mounting groove of the protective cover 1 is designed as an arc structure, which matches the motor shaft of the generator to ensure that the arc shape is concentric with the motor shaft; a long arc mounting hole 45 is designed on each side of the sensor bracket 4, and a chamfer is designed on the mounting hole structure The structure (mounting hole chamfer 46) can adjust the installation angle according to different motors to meet the needs of different motors; the plug of the sensor bracket 4 is a six-pin structure, and a pin 42 is installed on the sensor bracket 4 to output different functional definition requirements. Two plug buckles 47 are designed on both sides of the plug, which are buckled into a ladder-shaped structure. There is an angle designed near the end of the plug to facilitate the connection and fixation of the hand piece. A circuitous structure is designed inside the plug to facilitate the fixation and sealing of the hand piece; the sensor bracket 4 is designed with a semicircular arc structure 48, and two groove reinforcement ribs 491 are arranged on the surface of the groove 49 for limiting with the end cover.

[0043] The above describes the utility model and its implementation methods, which is not restrictive. What is shown in the full text is only one of the implementation methods of the utility model, and the actual structure is not limited thereto. In short, if ordinary technicians in this field are inspired by it, without departing from the purpose of the invention of the utility model, they can design a structure and embodiment similar to the technical solution without creativity, which should belong to the protection scope of the utility model.

Claims

1. A rotational speed sensor based on the Hall effect, characterized in that It comprises a sensor bracket (4), a protective cover (1), a circuit board assembly (2) and a Hall element (3), One side of the protective cover (1) is provided with a protective cover glue groove (14) for gluing the sensor bracket (4) and a protective cover Hall installation groove (11) for installing the Hall element (3), and the protective cover Hall installation groove (11) is filled with silicone grease potting glue; The Hall element (3) is connected to the circuit board assembly (2); The sensor bracket (4) is provided with two boss mounting columns (41), the circuit board assembly (2) is provided with mounting holes for use with the boss mounting columns (41), the sensor bracket (4) is provided with an insert pin (44), and the circuit board assembly (2) is provided with an insert pin welding hole (22) for welding the insert pin (44).

2. The rotational speed sensor based on the Hall effect according to claim 1, characterized in that: The circuit board assembly (2) is provided with a resistor (21) and a capacitor (23).

3. The rotational speed sensor based on the Hall effect according to claim 1, wherein: The Hall elements (3) are arranged in three groups, and one end of the Hall installation slot (11) of the protective cover close to the sensor bracket (4) is a protective cover bell mouth (13).

4. The rotational speed sensor based on the Hall effect according to claim 1, characterized in that: A sensor mounting protrusion (43) that matches the gluing groove (14) of the protective cover is installed on one side of the sensor bracket (4) close to the protective cover (1).

5. The rotational speed sensor based on the Hall effect according to claim 1, wherein: A pin (42) is installed on the sensor bracket (4).

6. The rotational speed sensor based on the Hall effect according to claim 1, characterized in that: The protective cover (1) is provided with protective cover reinforcing ribs (12).

7. The rotational speed sensor based on the Hall effect according to claim 1, characterized in that: The sensor bracket (4) is provided with a long arc mounting hole (45), and both sides of the long arc mounting hole (45) are mounting hole chamfers (46), and a plug buckle (47) is installed on the sensor bracket (4).

8. The rotational speed sensor based on the Hall effect according to claim 7, characterized in that: The side of the sensor bracket (4) away from the plug undercut (47) is a semicircular arc structure (48), and a groove (49) is provided on the sensor bracket (4) and a groove reinforcing rib (491) is installed in the groove (49).

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