Sensing element with unevenly distributed multiple magnetic sheet locations and magnetic flux inside casing

Abstract

The invention discloses a sensing element with non-uniform distribution of multiple magnetic block positions and magnetic flux in a casing and belongs to a technology of providing a control signal by multi-point magnetic induction. Permanent magnet blocks and a Hall are arranged in an inner hollow casing formed by embedding a rotary disk with a fixed disk; a plurality of permanent magnet blocks which are circularly distributed are fixedly arranged on the rotary disk; the permanent magnet blocks are different in space and magnetic flux; magnetic polarities of adjacent permanent magnets on a certain surface of the rotary disk are opposite, i.e., the magnet polarity distribution mode of all permanent magnet blocks on the certain surface is N pole, S pole, N pole and the like; and the Hall on the fixed disk is arranged at a position close to the permanent magnet block. The sensing element has the advantages that the magnetic polarities of adjacent permanent magnets are in an NS opposite distribution mode, so that the Hall can acquire a rectangular wave signal which is conveniently and digitally processed; by using the characteristics that the spaces and the magnetic fluxes are respectively different, the rectangular wave signal can express the position of the permanent magnet blocks on the rotary disk and determine purposes of different rectangular waves; and a relative position between the permanent magnet blocks and the Hall is fixed, and thus the reliability in signal output is realized.

Description

technical field [0001] The invention belongs to the technical field of providing signals by magnetic induction, and in particular relates to the technology of providing control signals by multi-point magnetic induction on a rotating component. Background technique [0002] The Chinese patent 201020295192.0 "Claw Type Torque Sensing Device" applied by Yebao Vehicle Material Industry (Kunshan) Co., Ltd. discloses a sensing device for power-assisted bicycles. The sensing device includes a magnetic part and an elastic part to sense the torque. sensing device. After a long time of use, the change of the elastic coefficient of the elastic member will lead to changes in the sensing signal and the control effect of the controlled motor, and the power-assisted effect will not match the power-assisted needs of people. Moreover, the design structure of the elastic member is complex and the manufacturing cost is high. [0003] The Chinese patent 01201843.0 "Automatic Detection Device ...

AI Technical Summary

Problems solved by technology

[0015] Disadvantages (1) Using two permanent magnets with no difference to represent the fixed positions of the two pedals, only multiple Halls can be used to represent the pedals Rotation position: There is no difference between the two permanent magnets. The advantage is that the fixed positions of the two pedals can be expressed regardless of the left and right feet, so that the left and right feet can generate power assistance requirements, which can produce the same motor power assistance effect; but the disadvantage is that The permanent magnetic steel itself cannot indicate the rotation position of the pedal, but can only use multiple Halls at different corner positions to indicate the rotation position of the pedal, so it is not possible to use only one Hall, but must use multiple Halls

[0016] Disadvantage (2) Only one Hall cannot be used, but three Halls will inevitably cause the original segmentation error of the three control signals, which will distort the power-assist demand model, naturally The generation of power output is inconsistent with the demand for power assistance: no matter whether the power-assisted bicycle has one or two motors, the sensor signal for controlling the motor can only be controlled by using one sensor signal input to the motor controller; and the patent uses three sensors. If Hall controls the motor, the three control signals of the three Halls must be combined into one combined control signal before it can be input to the motor controller

The sensing parameters of the three Halls cannot be the same, especially due to changes in ambient temperature and long-term use, the sensing parameters of the three Halls may vary greatly. The output voltages are different, resulting in different power output of the motor, and the power output is inconsistent with the power demand; similarly, when the power demand is the same, the outputs of different Halls may be the same voltage, resulting in the same power output of the motor, and also There is a problem that the power output is inconsistent with the power demand

However, such a structure limits the adjustment of the position of the permanent magnet on the rotating disk, resulting in a sensor with only one sensing model

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