摘要:
A coil sensor excited with alternating current and connected in a circuit for detecting changes in the coil impedance producing a signal exceeding a fixed threshold value in response to the revolution of a wheel with features providing periodic changes in the spacing between the coil and the wheel, has its periphery subdivided into zones where the surface material is alternately thereomagnetic and non-theromagnetic. With a suitable setting of the frequency of the exciting alternating current and a suitable choice of the materials with respect to their eddy current and magnetic induction effect on the inductance of the coil, it is possible to suppress the signal of once per revolution periodicity resulting from wheel eccentricity, bearing wobble or the like.
摘要:
An apparatus for contactless distance, or travel and/or speed measurement of bodies moving substantially uniformly is disclosed. The apparatus has zones of electrically conductive material which are displaced in synchronism with the body and a measuring transducer disposed at a distance therefrom and spatially fixed, the measuring transducer having a high-frequency alternating current flowing through it. To permit construction of a measuring transducer having large geometric dimensions while detecting narrow electrically conductive zones (10) of attaining measurement signals which are relatively invulnerable to malfunction, the measuring transducer (15) is extended spatially over a multiplicity of zones (10) and has individual, active measuring faces (16) which are interconnected and spatially demarcated. The distance of these active measuring faces (16) from one another, viewed in the direction of movement of the zones (10), corresponds substantially to the distance (b) of adjacent zones (10) and the width of the measuring faces, also viewed in the direction of movement of the zones (10), corresponds substantially to the width (c) of the zones (10).
摘要:
Fuel injection pump for internal combustion engines comprising a displacement pickup for determining the position of control elements arranged in a pump housing. The displacement pickup comprises a movable part, which is arranged in the pump housing and is connected with the control element, and a stationary part which is arranged on the outside of the pump housing. The position of the movable part of the displacement pickup is determined by the stationary part by means of a measuring process which measures in a contactless manner, e.g. by means of the induction or eddy current principle.
摘要:
A device for determining a length of linear movement of an angle of rotation of a machine part, and comprising spaced first and second bodies, a coil arranged on one of the first and second bodies, and a diaphragm connectable to a machine part for joint displacement therewith and arranged between the first and second bodies for movement relative to the one of the first and second bodies, which diaphragm has an area formed in such a manner than an inductive effect and an eddy current effect which result from axial oscillation of the diaphragm, upon flow of an alternating current through the coil, cancel each other with respect to their electrical action on the coil.
摘要:
An apparatus for the automatic release of passenger protection devices in motor vehicles in the event of an accident has a sensor (35) having a mass (10) secured outside the center of mass (11). This mass (10) generates a comparably high torque in the suspension in the event of both positional change and rotational acceleration. These torques are detected with known measuring methods and split, with the aid of a high-pass filter (36) and a low-pass filter (40), into a high-frequency and a low-frequency portion. The high frequency portion corresponds to the rotational acceleration, from which the rotational velocity is obtained by means of an integrator (38). The low-frequency portion corresponds to the position of the motor vehicle. Thus both measurement variables that must be detected for releasing a roll bar are obtained with a single sensor (35).
摘要:
To improve the output sensitivity of two concentric, telescopic sleeves (8, 9), respectively secured at their end portions to stub shafts (2, 5; 3, 4) which are aligned, and connected, for example, by a torsion element (1), so that torque being transmitted by the shafts through the torsion element can be determined, the sleeves are cut with axial slits (11, 16, 17) in which the cuts of one of the sleeves extend only over half the axial length and are offset with respect to each other, two windings (20, 21) being wound over a winding form (18) surrounding the outer one of the sleeves, and positioned centrally with respect to the half-slits (16, 17); upon applying high-frequency alternating current to the windings, and relative rotation of the sleeves, which will bring one of the half-slits in alignment with the axially extending slit (11) in the other sleeve, while rotating the other half-slit out of alignment, changes in inductance of the windings can be determined due to change in eddy currents being induced in the respective sleeve portions. The width (b) of the conductive sleeve portions (14, 15) to the width (a) of the slits which, effectively, form non-conductive circumferential portions, should be between 10:1 and 5:1, the spacing between the sleeves being as small as possible, for example in the order of 0.05 mm to 0.25 mm.
摘要:
Measuring apparatus for the torque transmitted through a shaft consists of a first and second induction member respectively mounted at the input and the output end of the shaft for rotation therewith. The induction members are discs or concentric cylindrical elements made of a conductive material, each member having sector-shaped cut-out portions. The sector-shaped cut-out portions of the two members are aligned for a predetermined starting torque. A coil is mounted opposite one of the members and generates a high frequency magnetic field. The magnetic field induces eddy currents in the members. The eddy currents in the second member increase as the conduction material of the second member shifts toward exposure to the coil through the cut-out portions of the first member. Increases in eddy currents cause decreases in inductivity of the coil which, when measured, constitute a measure of the transmitted torque.