Abstract: A strain detector wherein the efficiency of a detecting coil is improved to improve the sensitivity of the strain detector. The strain detector comprises a magnetic layer made of a soft magnetic material having a high permeability and fixedly mounted on an outer periphery of a driven shaft strain of which is to be detected, and a detecting coil disposed around the magnetic layer with a gap left therebetween for detecting a variation of the permeability arising from strain of the magnetic layer caused by an external force applied to the driven shaft. The strain detector further comprises a metal layer made of a non-magnetic material having a high electric conductivity and disposed in the gap between the magnetic layer and the detecting coil. Or else, the detecting coil has a pair of coil portions connected to each other by way of an intermediate portion thereof, and an electric current flows in the same direction through the coil portions.

Abstract: A strain detector wherein external and internal magnetic fields are magnetically separated from each other to eliminate an influence of such disturbance magnetic field to assure accurate and stabilized detection of strain in a drive shaft. The detector comprises a magnetic layer made of a soft magnetic material having a high permeability and suitable magnetostriction fixedly mounted on an outer periphery of a driven shaft, a pair of bearings or bearing stands made of a soft magnetic material having a high permeability for supporting the driven shaft for rotation thereon, a detecting coil disposed around the magnetic layer for detecting a variation of the permeability of the magnetic layer arising from strain of the magnetic layer caused by an external force applied to the driven shaft, and a shield disposed on an outer periphery of the detecting coil and magnetically connected at the axial opposite end portions thereof to the bearings or bearing stands.

Abstract: A shock absorber control apparatus which performs a fuzzy inference by use of a predetermined fuzzy rule regarding comfortable ride, steering stability and grounding efficiency corresponding to a detected running condition of a vehicle, thereby setting an optimum damping force. A shock absorber control apparatus which fetches a plurality of specified frequency components from a vertical acceleration signal of a vehicle body so as to perform a fuzzy inference by use of a fuzzy rule corresponding to a quantity of each frequency component, thereby setting an optimum damping force.

Abstract: A strain detector wherein the efficiency of a detecting coil is improved to improve the sensitivity of the strain detector. The strain detector comprises a magnetic layer made of a soft magnetic material having a high permeability and fixedly mounted on an outer periphery of a driven shaft strain of which is to be detected, and a detecting coil disposed around the magnetic layer with a gap left therebetween for detecting a variation of the permeability arising from strain of the magnetic layer caused by an external force applied to the driven shaft. The strain detector further comprises a metal layer made of a non-magnetic material having a high electric conductivity and disposed in the gap between the magnetic layer and the detecting coil. Or else, the detecting coil has a pair of coil portions connected to each other by way of an intermediate portion thereof, and an electric current flows in the same direction through the coil portions.

Abstract: In a strain measuring device employing a magnetic permeability detector means to detect an amount of strain in a passive member as changes of magnetic permeability in a magnetostrictive layer, a magnetic shielding layer is formed on the surface of the passive member, and the magnetostrictive layer is formed thereon so as to lessen the adverse effects of the passive member caused by the magnetic characteristics of the passive member in strain measurement, that is, to reduce measurement errors. Alternatively, a magnetostrictive layer is formed on the surface of the passive member, or a magnetic shielding layer is partially forrmed on the surface of the passive member of soft magnetic material with high permeability, so as to lessen the influence of the passive member caused by thermal stresses of the passive member in strain measurement, that is, to reduce measurement errors. Further, there is provided a strain measuring device which facilitates formation of the magnetostrictive layer.

Abstract: A strain detector for detecting a strain developed in a shaft applied with a torque comprises strain-sensitive magnetostrictive elements attached to the shaft in two groups in a chevron pattern. A pair of annular detection coils are wound around a bobbin to surround respective one of the groups of magnetostrictive elements. Two annular yokes made of a soft magnetic material of high permeability are disposed around respective coils across radial gaps. A hollow cylindrical shield of non-magnetic material with a high electrical conductivity is disposed around the two yokes across radial gaps. The magnetostrictive elements may be made of a nickel-iron alloy of 45 to 55% Ni-Fe. The yokes may be made of a nickel-iron alloy of about 80% Ni-Fe or alternatively, of a 6.5% Si-Fe steel. The detector may comprise a second magnetic shield disposed around the first shield of non-magnetic material with a high electrical conductivity. The second shield may be made of the same magnetic material as the yokes.

Abstract: This invention relates to a method for manufacturing a highly reliable stress detector. Conventionally, a step of bonding and securing magnetic elements (4) to a driven shaft (1) receiving a stress was needed, so that a high technique was needed to secure the magnetic elements (4) uniformly at the entire surface and transversely symmetrically, disadvantageously increasing the process cost.The present invention therefore has as its object the manufacture of a reliable stress detector by simplifying the process of securing the magnetic elements (4) and realizing a good attachment. According to this invention, a strip of magnetic thin sheet is secured around the driven shaft receiving a stress, and a selective coating removal treatment is applied to the magnetic thin sheet secured to the driven shaft to form magnetic elements parallelly arranged at a predetermined angle relative to the central axis of the driven shaft.

Abstract: A strain detector which has a driven shaft for receiving a stress; a high magnetostrictive rate magnetic layer made of one of Co--B, Co--P, Co--Ni--B, Ni--Fe--P, and Co--Ni--P formed by electroless plating on the outer periphery of the driven shaft; and a detecting coil disposed through a gap on the periphery of the magnetic layer for detecting a variation in the permeability by a strain responsive to the stress of the magnetic layer, a method for manufacturing the strain detector which has the steps of forming a high magnetostrictive plating layer made of one of Co--B, Co--P, Co--Ni--B, Ni--Fe--P and Co--Ni--P by electroless plating on the periphery of the driven shaft; and selectively removing the plating layer to obtain a magnetic layer made of a plurality of magnetic pieces aligned in parallel at a predetermined angle with respect to the central axis of the driven shaft.