Abstract: It is an object of the present invention to provide a method for producing a magnetostrictive element, capable of assuredly producing a magnetostrictive element by powder metallurgy. In a container for sintering 10, a compact 100 is sintered into a magnetostrictive element having a composition of SmFe2 while held by a support 20 of SmFe2 or Nb stable during the sintering step. The support 20 is composed of particles coming into contact with the compact 100 at multiple points, to control fusion-bonding between the support 20 and the compact 100 to a limited extent.

Abstract: A pressure sensor 10 includes a casing 12 configured to be able to be filled with a fluid 16 such as a liquid or a gas, in which at least part of a surface contacting this fluid 16 is formed of a giant magnetostrictive member 18 made of a giant magnetostrictive element, and detecting means for detecting a change in magnetic permeability or an amount of remanent magnetization attributable to expansion and contraction of the giant magnetostrictive member 18 based on a pressure change of the fluid 16 filled in this casing 12. The pressure sensor 10 can detect pressure at high sensitivity and high accuracy in a short time while achieving miniaturization of a device at the same time.

Abstract: An ultrasonic transducer includes a giant magnetostrictive rod 12 of a columnar shape which is made of a giant magnetostrictive member, and vibration plates 14 and 16 which are made of plate members having a larger diameter than that of the giant magnetostrictive rod 12 and are adhered and fixed to end surfaces in an axial direction of this giant magnetostrictive rod 12. The ultrasonic transducer can efficiently transmit ultrasonic vibration by expansion and contraction of the magnetostrictive rod in spite of a small and simple structure.

Abstract: A weight sensor 10 having a simple structure and yet being capable of detecting load or pressure of an object to be measured in a short time and with high sensitivity and high precision. The sensor includes a first rotating shaft 14 vertically and rotatably supported on a stage 12, a second rotating shaft 18 axially and coaxially connected to the first rotating shaft 14 with a magnetostrictive member 16 interposed therebetween for rotatably supporting an object 20 to be measured, and a pickup coil 28 for detecting changes in magnetic permeability or remnant magnetization of the magnetostrictive member 16. Load or pressure of the object 20 is detected as the changes in magnetic permeability or remnant magnetization, which are caused by extension and contraction of the magnetostrictive member 16.

Abstract: A gyro sensor 10 having a small and simple structure and yet being capable of detecting changes in angular speed with high sensitivity. The sensor 10 includes a giant magnetostrictive member 12 made of a giant magnetostrictive element, a drive coil 18 for vibrating the giant magnetostrictive member 12 by controlling the intensity of a magnetic field applied to the giant magnetostrictive member, and a GMR element (detecting means) 20 for detecting changes in magnetic permeability or remnant magnetization of the giant magnetostrictive member 12. Changes in angular speed around a rotation axis that is orthogonal to a direction in which the giant magnetostrictive member 12 vibrates are detected as the changes in magnetic permeability or remnant magnetization of the giant magnetostrictive member 12 caused by its deformation, which is brought about by the Coriolis force.

Abstract: A vibrating device that can be applied to various purposes other than as a vibrator and that can achieve cost reduction, size reduction, and space saving by a reduction in the number of components, and a mobile phone using this vibrating device are provided. The vibrating device has a housing supported by a base and capable of oscillating in a vibration frequency range of a vibrator, and an expandable rod that can expand and contract, one end of which is fixed to the housing, and the other end of which is a free end contacting the base. The base is resonated by oscillation of the housing in the vibration frequency range of a vibrator, while the base is vibrated by expansion and contraction of the expandable rod in a sound frequency range other than the vibration frequency range of a vibrator.

Abstract: A contraction type actuator 10 is provided which can efficiently and evenly apply a bias magnetic field to a magnetostrictive rod to obtain a large contraction amount, while having a small and simple structure. In the contraction type actuator 10, a giant magnetostrictive rod 12 flexibly expands and contracts by controlling the strength of a magnetic field applied by a magnet coil 14. A bias magnet comprises a first bias magnet 16 and a second bias magnet 18. The fist bias magnet 16 in an approximately cylindrical shape is coaxially disposed around the giant magnetostrictive rod 12. The second bias magnet 18 is disposed in the inner space 16A of the first bias magnet 16, and is polarized in the direction of drawing a part of a magnetic field generated by the first bias magnet 16 into the inner space 16A.

Abstract: Magnetostrictive devices, such as an actuator and a sensor, having a reduced hysteresis characteristic are provided. An actuator 10 includes a cylindrical magnetostrictive element 1 expanding or contracting in the axial direction by application of a driving magnetic field; an electromagnetic coil 2 placed on the outer surface side of the magnetostrictive element 1 and for applying the driving magnetic field; and a polar-anisotropic cylindrical magnet 3 placed on the inner surface side of the magnetostrictive element 1 and for applying a magnetic field to the magnetostrictive element 1. The polar-anisotropic cylindrical magnet 3 applies a magnetic field in the peripheral direction of the magnetostrictive element 1. The magnetic field orthogonally crosses the driving magnetic field applied to the magnetostrictive element 1 by the electromagnetic coil 2.

Abstract: To provide a method for producing a magnetostrictive material of excellent magnetostrictive characteristics. The method for producing a magnetostrictive material, wherein a mixture composed of Starting Materials A, B and C is sintered, where A is represented by Formula 1 (TbxDy1-x)Ty (T is at least one metallic element selected from the group consisting of Fe, Ni and Co, 0.35<x?0.50 and 1.70?y?2.00), B is represented by Formula 2 DytT1-t (0.37?t?1.00), and C contains T, to produce a magnetostrictive material represented by Formula 3 (TbvDy1-v)Tw (0.27?v<0.50, and 1.70?w?2.00), wherein oxygen content is set at 500 to 3,000 ppm for Starting Material A and at 2,000 to 7,000 ppm for Starting Material B.

Abstract: A torque sensor includes a substantially tubular giant magnetostrictive member, a shaft passing through the inner bore of the giant magnetostrictive member and capable of transmitting torque to the giant magnetostrictive member, and a detection coil for detecting changes in the magnetic permeability or remnant magnetization of the giant magnetostrictive member. Torque changes of the shaft are detected as changes in the magnetic permeability or remnant magnetization of the giant magnetostrictive member, based on the deformation of the giant magnetostrictive member. The torque sensor enables a reduction in the number of components and costs, as well as detection of torque changes with high sensitivity.

Abstract: A speaker has a vibration device disposed under a floor approximately in the shape of a board, which can vibrate in the direction of thickness. The floor can vibrate at least around the vibration device. Since the vibration device vibrates the floor, sound is emitted from a floor surface, and hence the sound is transmitted to a wide area above the floor surface.

Abstract: It is an object of the present invention to provide a sensor, a magnetostrictive element or the like having temperature stabilities. The sensor of the present invention for sensing a pedal pressure in an electric hybrid bicycle comprises a magnetostrictive element and a coil arranged on the outer circumferential side of the element, wherein the element is composed of a sintered body having a composition represented by TbxDy(1-x)Ty, wherein x is in the range: 0.50<x?1.00, T represents one or more transition metal elements, and y is in the range: 1<y<4. The sensor of the above structure has temperature stabilities. The electric hybrid bicycle can stably generate an auxiliary force, when incorporated with the torque sensor.

Abstract: To provide a method for producing a magnetostrictive material of excellent magnetostrictive characteristics. The method for producing a magnetostrictive material, wherein a mixture composed of Starting Materials A, B and C is sintered, where A is represented by Formula 1 (TbxDy1-x)Ty(T is at least one metallic element selected from the group consisting of Fe, Ni and Co, 0.35<x?0.50 and 1.70?y?2.00), B is represented by Formula 2 DytT1-t (0.37?t?1.00), and C contains T, to produce a magnetostrictive material represented by Formula 3 (TbvDy1-v)Tw (0.27?v<0.50, and 1.70?w?2.00), wherein oxygen content is set at 500 to 3,000 ppm for Starting Material A and at 2,000 to 7,000 ppm for Starting Material B.

Abstract: A setter 20 to be arranged in a sintering container 10 is provided with holes 21 to keep a compact 100 upright. The compact 100 is not in contact with the setter 20 at a temperature level at which the sintering reaction proceeds between them because of contraction of the compact 100 during sintering.

Abstract: In the step of sintering a compact that is finally to be a magnetostrictive element, when the temperature in a furnace is elevated, the atmosphere in the furnace is evacuated by a vacuum pump to keep the pressure in the furnace at negative pressure in a temperature range that allows thermal decomposition of hydride present in the compact to release hydrogen gas to accelerate release of hydrogen from the compact.

Abstract: Restoring magnetostriction characteristics without causing fusion of rod. By performing heat treatment on a giant magnetostrictive material within the temperature range of 750 to 860° C., working distortion is removed while bleeding of an R-rich phase on a rod surface is prevented.

Abstract: A method for manufacturing a sintered compact includes the steps of preparing an alloy powder having a composition represented by Expression 1: RTW (where, R is at least one kind of rare earth metal, T is at least one kind of transition metal, and w defines a relation of 1<w<4), sintering the alloy powder in a vacuum atmosphere or an atmosphere containing gas with a molecular weight of 30 or less, and processing the alloy powder by a hot isostatic pressing. The sintered compact has a high density, and reduces deteriorations in its sintered compact properties such as magnetostrictive properties in an air atmosphere at high-temperatures.

Abstract: ferrite magnet raw material particles and a non-aqueous solvent is compacted wet in a magnetic field, while said non-aqueous solvent is removed therefrom, to obtain a compact, and the compact is sintered to obtain an anisotropic ferrite magnet. In this case, a surface active agent is allowed to exist in the slurry during the wet compaction. Alternatively, in addition to or in place of this, the raw material particles are pulverized to apply strains thereto, thereby reducing the iHc values to preferably 3.5 kOe or less. This makes some considerable improvement in the degree of orientation of the compact, thus achieving much more improved magnet properties.

Abstract: To provide a multi-purpose type magnetostrictive device that may be used as an acceleration sensor or a vibration sensor capable of detecting forces acting in more than one direction and which may also be employed as a torque sensor, an actuator, a motor and the like.Coils 110 to 310 of magnetostrictive bodies 10 to 30 are wound around magnetostrictive members 120 to 320 in such a manner that voltages corresponding to enlongation/contraction of the magnetostrictive members 120 to 320 are generated. The magnetostrictive members 120 to 320 are each constrained at the two ends. The magnetic circuits 130 to 330 apply a bias magnetic field to the magnetostrictive members 120 to 320.

Abstract: A slurry containing ferrite magnet raw material particles and a non-aqueous solvent is compacted wet in a magnetic field, while said non-aqueous solvent is removed therefrom, to obtain a compact, and the compact is sintered to obtain an anisotropic ferrite magnet. In this case, a surface active agent is allowed to exist in the slurry during the wet compaction. Alternatively, in addition to or in place of this, the raw material particles are pulverized to apply strains thereto, thereby reducing the iHc values to preferably 3.5 kOe or less. This makes some considerable improvement in the degree of orientation of the compact, thus achieving much more improved magnet properties.