Low power consumption winch sensor based on tunneling magnetoresistance effect

Abstract

The utility model discloses a low -power consumption winch sensor based on tunnel magnetoresistance effect, including measurement module, signal conversion unit, casing, mandrel, magnetism carousel and detection component, magnetism carousel is connected with mandrel and synchronous rotation, and detection component includes TMR sensing element and N magnet, and magnetism carousel is equipped for embedding the mounting blind hole of magnet, TMR sensing element is located on the casing, including mounting panel and two sensing units, and the magnetic domain direction of two sensing units is perpendicular to the axis of rotation, and its reluctance signal is converted and is inputted measurement module through signal conversion unit, and the horizontal distance of the center of two sensing units and magnet to the axis of rotation is all R, and the center distance of two sensing units L < R * sin (180 DEG / N), this sensor is based on TMR tunnel magnetoresistance effect, and the detection sensitivity is high, and the energy consumption is low, and its output has the square wave signal of phase difference, can supply measurement module accurate analysis and calculate winch drum speed and steering, and its overall structure is simple, and the radial dimension is small, and is easy to install and control installation accuracy.

Description

Technical Field

[0001] This utility model relates to the field of sensor technology, specifically to a low-power winch sensor based on the tunneling magnetoresistive effect. Background Technology

[0002] Tunneling magnetoresistance (TMR) refers to the effect in a ferromagnetic-insulator thin film (approximately 1 nanometer)-ferromagnetic material where the tunneling resistance varies with the relative orientation of the two ferromagnetic materials. TMR exhibits promising application prospects due to its unique advantages, such as high magnetoresistance and high magnetic field sensitivity. Compared to other magnetoresistance and Hall effect sensors, TMR offers higher output signal, a wider linear operating range, and higher sensitivity.

[0003] Currently, TMR-based sensors can achieve two detection functions: one is steering detection, which uses a TMR sensing unit to sense the polarity change of magnets spaced apart on a magnetic rotor to determine the direction of rotation; the other is speed or angle detection, which uses one or two TMR sensing units to sense the magnetic resistance change of closely arranged magnets on a magnetic rotor, outputs a pulse voltage signal, and calculates the speed or angle. However, the existing TMR-based sensor layouts can only support individual speed or steering tests, and cannot simultaneously obtain steering and speed tests by analyzing their output signals, which limits the application range of TMR sensors. In addition, the sensor assembly accuracy affects its detection error.

[0004] Based on this, this utility model optimizes the arrangement structure of the TMR sensing unit and the magnets on the magnet rotor, and improves the assembly method, so that the sensor can meet the detection requirements of synchronous detection of the winch's steering and rotation speed. Utility Model Content

[0005] The purpose of this invention is to provide a low-power winch sensor based on the tunneling magnetoresistive effect, thereby overcoming, to at least to some extent, one or more problems caused by the limitations and defects of related technologies.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A low-power winch sensor based on tunneling magnetoresistive effect includes a measurement module, a signal conversion unit, a housing, a spindle, a magnetic turntable, and a detection component. One end of the spindle is connected to the winch drum, and the magnetic turntable is connected to the spindle and rotates synchronously. The detection component is encapsulated in the housing and includes a TMR sensing element and N magnets. The magnetic turntable has N blind mounting holes evenly distributed around its rotation axis. The magnets are cylindrical and are embedded in the blind mounting holes parallel to the rotation axis. The TMR sensing element is fixedly mounted on the housing and includes a mounting plate, a first sensing unit, and a second sensing unit. The mounting plate is parallel to the magnetic turntable directly below it. The first and second sensing units are located on the mounting plate, and their magnetic domain directions are perpendicular to the rotation axis. The magnetoresistive signals collected by both are converted into square wave pulse signals by the signal conversion unit and input into the measurement module for analysis and calculation of steering and rotation speed. The horizontal distance from the center of the first sensing unit, the second sensing unit, and the magnets to the rotation axis is R, and the center distance L between the first and second sensing units is < R × sin(180° / N).

[0008] Furthermore, the signal conversion unit includes an operational amplifier, a Schmitt trigger, a signal driver chip, and a MOSFET push-pull circuit connected in series. The signal acquired by the first sensing unit is converted and amplified by the signal conversion unit to output a first square wave pulse signal. The signal acquired by the second sensing unit is converted and amplified by the signal conversion unit to output a second square wave pulse signal. The two signal conversion units output the first square wave pulse signal and the second square wave pulse signal, which have a phase difference, to the measurement module. The phase difference is less than the pulse width / 2.

[0009] Furthermore, a high-resistance resistor is connected in series at the input terminal of the measurement module. The measurement module includes a pulse calculation unit and a steering determination unit. The pulse calculation unit is used to calculate the rotational speed based on the number of pulses of the first square wave pulse signal or the second square wave pulse signal per unit time. The steering determination unit is used to determine the steering direction based on the correspondence between the falling edge of the first square wave pulse signal and the resistance state of the second square wave pulse signal.

[0010] Furthermore, both the first sensing unit and the second sensing unit include a free layer, a barrier layer, and a reference layer arranged sequentially from bottom to top, and are fixed side by side on a substrate. The substrate is an FR-4 glass fiber reinforced epoxy resin composite substrate, on which copper circuits for connecting the first sensing unit and the second sensing unit are printed.

[0011] Furthermore, the housing is mounted on the winch frame via a mounting bracket. A turntable groove is provided inside the housing. The bottom of the turntable groove has a bearing groove in the middle and a sensing groove near the side edge. The TMR sensing element is fixedly installed in the sensing groove. The spindle includes a threaded connection section, a support section, and a convex section. The threaded connection section is threaded to the winch drum. The support section is supported by a bearing in the bearing groove. The magnetic turntable is clamped and screwed to the convex section. An adjusting shim is provided between the TMR sensing element and the bottom of the sensing groove to adjust the distance between the TMR sensing element and the end face of the magnet.

[0012] Furthermore, the bearing groove is provided with two bearings jointly supporting the support section, and the bearings and the support section are interference fit.

[0013] Furthermore, the mounting bracket elastically supports the housing, which includes a support inclined plate and two end plates formed by bending the two ends of the support inclined plate respectively. One end plate is connected to the lower end face of one side of the housing, and the other end plate is connected to the winch frame, which is used to elastically deform to adapt to the installation of the mandrel and provide elastic support to the end face of the support section.

[0014] Furthermore, the housing is provided with a sealing plate to cover the turntable groove, and a central hole is opened in the center of the sealing plate. The other end of the spindle passes through the central hole and extends out of the turntable groove, and is provided with an operating head for rotating operation.

[0015] Compared with existing technologies, the low-power winch sensor based on the tunneling magnetoresistance effect of this invention has the following advantages:

[0016] This sensor is based on the TMR tunneling magnetoresistance effect, offering high detection sensitivity and low energy consumption. The two sensing units are influenced by the regularly changing magnetic field of the ring-shaped distributed magnet, successively exhibiting high-resistance or low-resistance states. A signal conversion unit amplifies and converts the signal into a square wave, outputting a square wave signal that the measurement module can accurately analyze and calculate the rotational speed. The spacing between the two sensing units is controlled to create a phase difference in their output square wave signals. This phase difference results in different correspondences between square wave signals for different directions of rotation, facilitating rapid and accurate determination of the winch drum's direction of rotation. Furthermore, the sensor has a simple overall structure and small radial dimensions. It uses cylindrical magnets embedded in a disc as a variable magnetic field source, making installation easy and allowing for precise control of installation accuracy. The magnetic disc and TMR sensing elements are fixedly mounted on different components, and the spindle is connected to the housing via bearings, reducing contact friction between the spindle / disc and the housing and improving the sensor's detection accuracy. Attached Figure Description

[0017] Figure 1 A three-dimensional structural view of the sensor of this utility model is disclosed;

[0018] Figure 2 Exploded views of the sensor components of this utility model are disclosed.

[0019] Figure 3A cross-sectional view of the sensor of this utility model is disclosed;

[0020] Figure 4 It was made public. Figure 2 A three-dimensional view of the TMR sensing unit in the middle;

[0021] Figure 5 This is a schematic diagram of the signal sensing of the detection device disclosed in this utility model;

[0022] Figure 6 for Figure 4 A schematic diagram of the signals collected by the magnetic turntable along the first rotation direction;

[0023] Figure 7 for Figure 4 A schematic diagram of the signals collected by the magnetic turntable along the second rotation direction;

[0024] Figure 8 This is a circuit diagram of the signal conversion unit of the sensor of this utility model.

[0025] In the figure: 1. Mounting bracket; 2. Mandrel; 3. Sealing plate; 4. Housing; 41. Sensing slot; 5. Magnetic turntable; 51. Magnet; 6. TMR sensing element; 61. Mounting plate; 62. First sensing unit; 63. Second sensing unit; 64. Substrate; 7. Bearing; 8. Lead wire assembly. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only the preferred embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0027] This embodiment provides a low-power winch sensor based on the tunneling magnetoresistive effect, such as... Figures 1-5 As shown, it includes a measurement module, a signal conversion unit, a housing 4, a spindle 2, a magnetic turntable 51, and a detection assembly; wherein,

[0028] The spindle 2 is used to transmit the rotation information of the winch drum. It is sequentially equipped with a threaded connection section, a support section, a convex section and an operating head. The threaded connection section at one end is threaded to the winch drum and rotates synchronously around the center line of rotation of the winch drum. The convex section is embedded in the magnetic turntable 51 and is connected by screws to form a synchronous rotation structure. The support section is interference-fitted with double bearings 7 to ensure the smooth rotation of the magnetic turntable 51 and effectively reduce the sway and vibration of the spindle 2 during high-speed rotation.

[0029] The detection component is used to collect the rotation information of the roller. It is encapsulated in the housing 4 and a seal is provided to seal the gap between the housing 4 and the spindle 2 to achieve dustproof and waterproof protection. Specifically, the detection component includes a TMR sensing element 6 and N magnets 51. The upper surface of the magnetic turntable 51 has N blind holes that are adapted to the magnets 51. The N blind holes are evenly distributed in a ring around the rotation axis of the magnetic turntable 51. The magnets 51 have a cylindrical structure and are embedded and fixed in the blind holes. The magnets 51 are parallel to the rotation axis, and their polarity is perpendicular to the surface of the magnetic turntable 51. All magnets 51 have the same polarity orientation.

[0030] The TMR sensing element 6 is fixedly mounted on the housing 4, such as Figure 4 As shown, it includes a mounting plate 61, a substrate 64, a first sensing unit 62, and a second sensing unit 63. The first sensing unit 62 and the second sensing unit 63 are tunneling magnetoresistive sensing units, arranged side-by-side and soldered onto the substrate 64. The substrate 64 is mounted on the mounting plate 61. Both the first sensing unit 62 and the second sensing unit 63 include a free layer, a barrier layer, and a reference layer arranged sequentially from bottom to top. The magnetic domain directions of the free layer and the reference layer are perpendicular to the axis of rotation. Figure 5 As shown, affected by the change in the magnetic field strength of magnet 51, the tunneling magnetoresistive induction unit generates a constantly changing tunneling current, which exhibits a dynamic sinusoidal change. This changing magnetoresistive signal is acquired by the signal conversion unit and converted into a square wave pulse signal, which is then input into the measurement module for analysis and calculation of the rotational speed.

[0031] In order to obtain analyzable signals of steering and rotation speed synchronously based on the sensor structure, the first sensing unit 62 and the second sensing unit 63 are located directly below the mounting ring of the magnet 51. That is, the horizontal distance from the center of the first sensing unit 62 and the second sensing unit 63 to the axis of rotation is equal to the horizontal distance from the magnet 51 to the axis of rotation, both being R. The center distance L of the first sensing unit 62 and the second sensing unit 63 is less than R×sin(180° / N). Thus, when the magnetic turntable 51 rotates, the magnetoresistive change pulses generated by the magnet 51 on the first sensing unit 62 and the second sensing unit 63 can form a phase difference. Under different steering, the signal outputs of the first sensing unit 62 and the second sensing unit 63 have different corresponding relationships. The steering can be obtained by analyzing the phase difference information.

[0032] To facilitate the installation and adjustment of the TMR sensing element 6, the housing 4 is provided with a turntable groove and mounting holes. The magnetic turntable 51 is non-contactly installed in the turntable groove. A bearing groove is opened at the center of the bottom of the turntable groove. The bearing 7 is interference-fitted to the support section of the spindle 2 and then transitionally installed in the bearing groove. A retaining ring is provided at the end. The rotation axis of the spindle 2 is collinear with the central axis of the housing 4. An induction groove 41 is opened at the bottom of the turntable groove off-center. Two mounting screw holes are provided at the bottom of the induction groove 41. A lead wire hole penetrating the wall of the housing 4 is provided on its side. A lead wire assembly 8 can be detachably installed in the lead wire hole to fix and protect the signal and power leads of the TMR sensing element 6. A connection hole for connecting with the mounting screw holes is opened on the mounting plate 61. An adjustment shim is provided at its bottom to adjust the distance between the TMR sensing element 6 and the bottom surface of the magnetic turntable 51.

[0033] As a further technical solution, substrate 64 is an FR-4 glass fiber reinforced epoxy resin composite substrate 64, on which signal connection circuits and power supply circuits are printed. A signal conversion unit can be disposed on substrate 64 and connected to a sensing unit. The measurement module is an external processing unit, such as... Figure 8 As shown, the signal conversion unit includes an operational amplifier, a Schmitt trigger, a signal driver chip, and a MOSFET push-pull circuit connected in series. The sinusoidal waveform acquisition signal, after amplification and square wave conversion, is enhanced by the MOSFET push-pull circuit and output, improving the calculation accuracy of speed and direction. The acquisition signal from the first sensing unit 62 is level-converted and enhanced by the signal conversion unit, outputting a first square wave pulse signal. The acquisition signal from the second sensing unit 63 is level-converted and enhanced by the signal conversion unit, outputting a second square wave pulse signal. Since L < R × sin(180° / N), there is a phase difference between the first and second square wave pulse signals. The phase difference is < pulse width / 2. Figure 6 As shown, when rotating in the first direction, the square wave signal of the first sensing unit 62 lags behind that of the second sensing unit 63 by a phase difference. That is, when the signal wave of the first sensing unit 62 enters the falling edge, the second sensing unit 63 is already in a low-impedance state. Figure 7 As shown, when rotating in the second direction, the square wave signal of the first sensing unit 62 is one phase difference ahead of the square wave signal of the second sensing unit 63. That is, when the signal wave of the first sensing unit 62 enters the falling edge, the second sensing unit 63 is still in the high impedance state. Based on this, the measurement module can accurately analyze the direction of the winch drum.

[0034] As a further technical solution, a high-resistance resistor is connected in series at the input terminal of the measurement module (not shown in the figure). When its input impedance reaches 1KΩ, the power consumption of the sensor can be reduced to 2mW, so as to further achieve the purpose of extremely low power consumption. The measurement module has a built-in pulse calculation unit and a direction determination unit. The pulse calculation unit counts the number of pulses of the first square wave pulse signal or the second square wave pulse signal and calculates the output drum speed. According to the above method, the direction determination unit determines the direction of the drum based on the correspondence between the falling edge of the first square wave pulse signal and the resistance state of the second square wave pulse signal.

[0035] As a further technical solution, the structure and installation of the sensor must meet the requirements of synchronous transmission of rotational motion on the magnetic turntable 51 and relative static acquisition of the TMR sensing element 6. To meet installation requirements and precise assembly, the housing 4 is mounted on the winch frame via a flexible support bracket 1. Figures 1-3 As shown, the mounting bracket 1 includes a support inclined plate and two end plates formed by bending the two ends of the support inclined plate. One end plate is connected to the lower end face of one side of the housing 4, and the other end plate is connected to the winch frame. When the sensor is installed, the mounting bracket 1 is first used to position and initially support the sensor. Since the mounting bracket 1 has a certain elastic deformation, the housing 4 can be finely adjusted to adapt to the installation of the spindle 2. After the installation is completed, the mounting bracket 1 generates an elastic support force opposite to the fixing direction of the spindle 2 to prevent the spindle 2 and the housing 4 from moving relative to each other and to ensure assembly reliability.

[0036] In addition, the other end of the spindle 2 is provided with an operating head for rotating operation. The center hole is opened in the center of the sealing plate 3 of the turntable groove of the housing 4. The other end of the spindle 2 extends out of the center hole. The operating head located outside the turntable groove can easily rotate and disassemble the spindle 2.

[0037] The directional terms "inner," "outer," "upper," "lower," "side," and "end" mentioned in this article are used to describe... Figures 1-5 The coordinates or orientations shown are not intended to limit the indicated devices, elements, or components to having a specific orientation or to be constructed and operated in a specific orientation.

[0038] Furthermore, in addition to indicating direction or positional relationship, some of the aforementioned terms may also have other meanings. For example, the terms "above" and "inside" may also be used in certain situations to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this utility model according to the specific circumstances.

[0039] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A low-power winch sensor based on the tunneling magnetoresistive effect, characterized in that: The device includes a measurement module, a signal conversion unit, a housing, a mandrel, a magnetic turntable, and a detection assembly. One end of the mandrel is connected to a winch drum, and the magnetic turntable is connected to the mandrel and rotates synchronously. The detection assembly is encapsulated within the housing and includes a TMR sensing element and N magnets. The magnetic turntable has N blind mounting holes evenly distributed around its rotation axis. The magnets are cylindrical and are embedded in the blind mounting holes, parallel to the rotation axis. The TMR sensing element is fixedly mounted on the housing and includes a mounting plate, a first sensing unit, and a second sensing unit. The mounting plate is parallel to the magnetic turntable directly below it. The first and second sensing units are located on the mounting plate, with their magnetic domain directions perpendicular to the rotation axis. The magnetoresistive signals collected by both are converted into square wave pulse signals by the signal conversion unit and input into the measurement module for analysis and calculation of steering and rotation speed. The horizontal distance from the center of the first sensing unit, the second sensing unit, and the magnet to the rotation axis is R, and the center distance L between the first and second sensing units is less than R × sin(180° / N).

2. The low-power winch sensor based on tunneling magnetoresistance effect according to claim 1, characterized in that: The signal conversion unit includes an operational amplifier, a Schmitt trigger, a signal driver chip, and a MOS transistor push-pull circuit connected in series. The signal acquired by the first sensing unit is converted and amplified by the signal conversion unit to output a first square wave pulse signal. The signal acquired by the second sensing unit is converted and amplified by the signal conversion unit to output a second square wave pulse signal. The two signal conversion units output the first square wave pulse signal and the second square wave pulse signal, which have a phase difference, to the measurement module. The phase difference is less than the pulse width / 2.

3. The low-power winch sensor based on tunneling magnetoresistance effect according to claim 2, characterized in that: The measurement module has a high-resistance resistor connected in series at its input terminal. The measurement module includes a pulse calculation unit and a steering determination unit. The pulse calculation unit is used to calculate the rotational speed based on the number of pulses of the first square wave pulse signal or the second square wave pulse signal per unit time. The steering determination unit is used to determine the steering direction based on the correspondence between the falling edge of the first square wave pulse signal and the resistance level of the second square wave pulse signal.

4. The low-power winch sensor based on tunneling magnetoresistance effect according to claim 2, characterized in that: Both the first sensing unit and the second sensing unit include a free layer, a barrier layer and a reference layer arranged sequentially from bottom to top, and are fixed side by side on a substrate. The substrate is an FR-4 glass fiber reinforced epoxy resin composite substrate, on which copper circuits for connecting the first sensing unit and the second sensing unit are printed.

5. The low-power winch sensor based on tunneling magnetoresistive effect according to any one of claims 1 to 4, characterized in that: The housing is mounted on the winch frame via a mounting bracket. A turntable groove is provided inside the housing. The bottom of the turntable groove has a bearing groove in the center and a sensing groove near the side edge. The TMR sensing element is fixedly installed in the sensing groove. The spindle includes a threaded connection section, a support section, and a convex section. The threaded connection section is threaded to the winch drum. The support section is supported by a bearing in the bearing groove. The magnetic turntable is clamped and screwed to the convex section. An adjusting shim is provided between the TMR sensing element and the bottom of the sensing groove to adjust the distance between the TMR sensing element and the end face of the magnet.

6. The low-power winch sensor based on tunneling magnetoresistive effect according to claim 5, characterized in that: The bearing groove is provided with two bearings that jointly support the support section, and the bearings and the support section are interference fit.

7. The low-power winch sensor based on tunneling magnetoresistive effect according to claim 5, characterized in that: The mounting bracket elastically supports the housing and includes a support inclined plate and two end plates formed by bending the two ends of the support inclined plate. One end plate is connected to the lower end face of one side of the housing, and the other end plate is connected to the winch frame. It is used to elastically deform to adapt to the installation of the mandrel and provide elastic support to the end face of the support section.

8. The low-power winch sensor based on tunneling magnetoresistance effect according to claim 5, characterized in that: The housing is provided with a sealing plate to cover the slot of the turntable groove. A central hole is opened in the center of the sealing plate. The other end of the spindle passes through the central hole and extends out of the turntable groove, and is provided with an operating head for rotating operation.

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