摘要:
A magnetic sensor element 1 includes a substrate 10, a conductive layer 12 of a conductive material, and a magnetic layer 11 of a magnetic material, which encloses the conductive layer 12. AC is applied to the element from a drive power source 50, and a detector 60 detects an impedance change due to an external magnetic field. The magnetic layer 11 is bestowed with magnetic anisotropy in a direction orthogonal to the direction of energization of the element 1. With the provision of the conductive layer 12 of conductive material and also with magnetic anisotropy imparted to the magnetic layer 1, the element 1 may be made a low resistivity element. A reactance change and a resistance change of the element due to an external magnetic field change, thus can be effectively detected in drive frequencies two orders of magnitude lower than in the case of a prior art magnetic sensor element. The magnetic anisotropy of the magnetic layer 11 is controlled to prevent magnetic field detection dynamic range variations with drive frequency.
摘要:
A torque detecting apparatus for measuring the amount of magnetostriction of a rotary magnetic material which transmits torque by means of a magnetic sensor, and detecting the transmitted torque on the basis of the measured amount of magnetostriction. The apparatus comprises a magnetic sensor for measuring the amount of magnetostriction of the rotary magnetic material, a demagnetization coil which is opposed to the rotary magnetic material so as to restore the rotary magnetic material magnetized by a disturbing magnetic field to the state of zero magnetization, a demagnetization circuit for applying an oscillating current to the demagnetization coil so as to generate in the rotary magnetic material a periodic damping oscillating magnetic field having the maximum value larger than the coercive force of the rotary magnetic material; and a trigger circuit for outputting a drive timing signal for the demagnetization circuit. The transmitted torque is detected without being influenced by a disturbing magnetic field.
摘要:
A torque measuring apparatus including a magnetic detection device for non-contact measuring strains in a rotating shaft of ferromagnetic material which is adapted to transmit torques, the detected strains being used to determine the levels of transmitted torques, the magnetic detection device including an exciting coil device wound around the outer periphery of the rotating shaft and adapted to magnetize the rotating shaft in its axial direction; a detecting core ring device in the form of an integral unit which includes a plurality of detecting cores arranged around the circumferential area of the rotating shaft to be magnetized equidistantly to form a ring, each of the detecting cores forming an independent magnetic circuit between the detecting core and the rotating shaft; and at least one magnetic detecting element for detecting a variable magnetic flux in each of the detecting cores depending on the level of the transmitted torque; whereby the strains in the rotating shaft can be non-contact measured based on the sum of detection signals from the magnetic sensors each of which is formed by each of the detecting cores and the corresponding magnetic detecting elements.
摘要:
A torque sensor which can detect instantaneous output torque of the engine is disposed on the output shaft of the engine, and the output signal thereof is frequency-analyzed to extract a half synchronous frequency component having a frequency equals to a half of the number of the revolutions of the engine per second and a synchronous frequency component having a frequency equals to the number of the revolutions of the engine per second, the electronic control unit (ECU) of the engine determines the misfiring mode of the engine including the number of the misfiring cylinders and the interval thereof in the firing order of the engine based on the amplitude of the frequency components and the waveform thereof, then the ECU determines the misfiring cylinders based on the determined misfiring mode and the phase angle of the frequency components of the torque sensor relative to a reference crank angle signal.
摘要:
A physical quantity detecting apparatus for detecting a physical quantity of an object of measurement. The position of movement of an object of measurement is divided into a given number of segments in advance. The output of a physical quantity sensor for detecting a physical quantity of the object of measurement is calculated on the basis of a correction operation expression which has an independent coefficient group for each segment so as to correct the offset component and the sensitivity. Thus, a physical quantity such as a transmitted torque is detected with high accuracy at real time without being influenced by the fluctuations of the offset output and the sensitivity depending on the position of rotation. The correction operation may also be performed using the temperature dependence function of the offset signal and the temperature dependence function of the sensitivity, thereby enabling the accurate measurement of the physical quantity without the influence of the temperature change.
摘要:
the present invention provides a force transducer having high compression fracture strength and high detection sensitivity, thus satisfying both detection precision and reliability, and also a method of fabricating such a force transducer. The force transducer is so constructed that a compression force is transferred via a pressure transfer block to narrow strain gages, which protrude from the surface of a silicon substrate and provide a small pressure-bearing area. Therefore, large compression strains act on the strain gages and thus the detection sensitivity is increased. When the compression force exceeds a predetermined value, the pressure transfer block comes into contact with the surface of the silicon crystal, thus improving the fracture strength of the strain gages. These narrow, protruding strain gages can be fabricated easily by a single mesa etching process.
摘要:
A torque measuring apparatus for detecting torque in a noncontacting state on the basis of the magnetostrictive amount of a rotary magnetic member for transmitting the torque which is detected by means of a magnetic sensor. The measuring apparatus comprises: a timing signal generator for dividing the rotational angle of the rotary magnetic member into a given number of segments and outputting a predetermined timing signal every time a rotational angle of the rotary magnetic member passes each segment; an offset signal generator for setting in advance for each segment an offset signal to be output from the magnetic sensor depending upon the rotational angle of the rotary magnetic member, and subsequently outputting an offset signal which corresponds to a respective segment on the basis of the timing signal; and a subtractor for subtracting the offset signal from the detection signal of the magnetic sensor at each segment, whereby the transmitted torque of the rotary magnetic member is measured on the basis of the output of the subtractor.
摘要:
A stress detector including an AC power source for generating an AC symmetrical wave form voltage, an exciting coil driven by the AC power source for alternatingly magnetizing at least a portion of a ferromagnetic material to be measured in a predetermined direction, a detecting coil for detecting a magnetic flux generated due to the alternating magnetization, and an adder circuit for taking out a part of a voltage applied to the exciting coil, setting an amplitude and a phase of a wave form of the taken-out part of the voltage to preset values, adding the voltage thus obtained to a voltage induced in the detecting coil. The detector gives an output signal representative of a value of stress applied to the material to be measured as a variation either in amplitude or phase depending on the preset phase.
摘要:
A vibration-sensing device (10) with high sensitivity includes a torsion bar (16) fixed on both ends thereof to a frame, a tuning fork-shaped vibrating member (12) joined with and supported by the torsion bar (16), and first and second torsion vibrating bodies (14,15) symmetrically projected from the torsion bar (16). The torsion bar (16), the tuning fork-shaped vibrating member (12), and the torsion vibrating bodies (14,15) constitute a torsion vibrating system. The application of an angular velocity to the vibration-sensing device (10) under the condition of plane vibrations of first and second vibrating tines (12a, 12b) of the first tuning fork-shaped vibrating member (12) along an X axis generates Coriolis forces to drive torsion vibration of the first tuning fork-shaped vibrating member (12) round the torsion bar (16), thereby driving torsion vibration corresponding to the angular velocity in the torsion vibrating system. The torsion vibration is amplified by the first and second torsion vibrating bodies (14,15) and detected by torsion vibration-detecting piezoelectric elements (20a,20b) attached to the torsion vibrating bodies (14,15). An angular velocity sensor using the vibration-sensing device, and a method of adjusting the sensitivity of the device are also provided.
摘要:
A torque sensor for detecting variation in the drive torque of an automobile comprises an excitation coil wound on an excitation core and a detection coil wound on a detection core. The coils and cores are inserted into a chamber formed within a bearing for supporting a drive shaft and having an opening along the sliding surface of the bearing. The poles of the excitation core and the poles of the detection core are respectively disposed at prescribed clearances from the surface of the drive shaft in such manner that the poles of the detection core intersect the excitation core between its poles, whereby variation in drive torque is detected as magnetostriction.