Tdk Corporation

Sae Magnetics (h.k.) Limited

Toshio Ishikawara

Toshihiko Oyama

Takahiro Moriya

Keiji Suzuki

Tatsuya Kato

Toshinao Kido

Seiji Fukuoka

A position detection device includes a magnetic scale and a magnetic sensor. The magnetic scale includes a plurality of magnets arranged along a first reference direction. The magnetic sensor includes a plurality of detectors that detect a composite magnetic field. The plurality of detectors are each arranged to satisfy AG=N(M−W)/(n−1), where n is the number of magnets of the magnetic scale, M is a distance from a first end to a second end, W is the width of each of the plurality of magnets and is greater than 0 and less than or equal to M/n, AG is a gap between each of the plurality of magnets and each of the plurality of detectors in a second reference direction, and N is a number greater than or equal to 0.4 and less than or equal to 2.

Position detection device

The present invention aims at providing A magnetic sensor that is less expensive and that is highly sensitive is provided. A magnetic sensor of the present invention has: a magnetic field detecting element; and a plurality of magnets that are arranged at intervals in a first direction, the magnets moving in the first direction relative to the magnetic field detecting element. The magnets have respective first faces that face the magnetic field detecting element. The magnets are magnetized in a second direction that crosses the first direction such that the first faces of an adjacent pair of the magnets have different polarities. The magnetic sensor further includes at least one soft magnetic body that is provided on the first face of at least one of the magnets.

Magnetic sensor, brake system using the same, and steering system using the same

An angle detection apparatus includes a magnetic sensing element, a magnetic field generator, and a yoke. The magnetic field generator is rotatable around a rotation axis with respect to the magnetic sensing element and generates a magnetic field. The yoke is disposed in a magnetic-field influence region and is rotatable together with the magnetic field generator. The magnetic-field influence region is a region that lies between the magnetic field generator and the magnetic sensing element in a rotation axis direction along the rotation axis, and that is to be influenced by the magnetic field.

Angle detection apparatus, angle detection system, park lock system, pedal system, and magnetic field generation module

A stroke sensor that allows adjustment of the magnetic field distribution without changing the positions of the magnets is provided. Stroke sensorhas magnetsA,B, and sensorA that detects a magnetic field that is generated by magnetsA,B. MagnetsA,B are movable relative to sensorA in first direction X. MagnetA has surfaceA that faces sensorA in second direction Z, magnetB has surfaceB that faces sensorA in second direction Z, and surfaceA and surfaceB have different polarities. A position in first direction X at which magnetic field intensity in second direction Z is zero is positioned between reference axis RA and magnetB. Reference axis RA is parallel to second direction Z and passes through middle point MP of minimum section S that includes magnetsA,B in first direction X.

Stroke sensor and brake system and steering system for vehicle using the same

A stroke sensor module is provided in which the contact area where the moving element slides on the main body is limited. A stroke sensor module has: a moving element that is moved in a first direction; a magnetic field generator that is moved in the first direction together with the moving element; a magnetic field detecting element that detects movement of the magnetic field generator; and a housing that houses a part of the moving element and the magnetic field generator. At least either the moving element or the magnetic field generator has a plurality of protrusions that are provided at different angular positions, as viewed in the first direction, and the housing has guide portions that guide the protrusions.

Stroke sensor module, structure and method for mounting stroke sensor module

Magnetic field generating unit is fixed to object that moves relative to magnetic field detecting means. Magnetic field generating unit has magnetic field generator, first support structure that is fixed to object and second support structure that is independent of first support structure. Second support structure is supported by first support structure and supports magnetic field generator. For example, second support structure is formed of a nonmagnetic material, and magnetic field generator is arranged away from first support structure.

Magnetic field generating unit, position detecting device and method of manufacturing magnetic field generating unit

A magnetic sensor device for detecting linear movement of a moving body includes a magnetic field generation unit and a magnetic field detection unit, which is provided to be capable of detecting the magnetic field generated by the magnetic field generation unit. The magnetic field detection unit is provided to be relatively moveable along a first axis accompanying linear movement of the moving body. The first axis is parallel to the direction of movement of the moving body. The magnetic field generation unit includes a first magnetic field generation unit and a second magnetic field generation unit. The first magnetic field generation unit and the second magnetic field generation unit are arranged substantially parallel to the first axis. A first line segment parallel to a first magnetization direction of the first magnetic field generation unit is inclined with respect to a second axis orthogonal to the first axis. A second line segment parallel to a second magnetization direction of the second magnetic field generation unit is inclined with respect to the second axis. The first line segment and the second line segment are positioned symmetrically with respect to the second axis and intersect each other to open toward the first axis.

Magnetic sensor device

A method of installing a stroke sensor that enables the stroke sensor to be adjusted in a simple process is provided. The method has the steps of: arranging a second magnet, relative to the magnetic field detecting element, at a physically determinable first reference position and obtaining an indicator value S1; attaching the first magnet and the magnetic field detecting element to structures different from each other, respectively, and positioning the first magnet, relative to the magnetic field detecting element, at a physically determinable second reference position, and obtaining an indicator value S2, wherein the second reference position corresponds to the first reference position; calculating &#x394;S=S1-S2, wherein &#x394;S is a difference between the indicator value S1 and the indicator value S2; and modifying a process in the processor such that a sum of the indicator value S and &#x394;S is outputted.

Method of installing stroke sensor

Magnetic field generating unitis fixed to objectthat moves relative to magnetic field detecting means. Magnetic field generating unithas magnetic field generator, first support structurethat is fixed to objectand second support structurethat is independent of first support structure. Second support structureis supported by first support structureand supports magnetic field generator. For example, second support structureis formed of a nonmagnetic material, and magnetic field generatoris arranged away from first support structure

A method for installing a stroke sensor is provided such that the stroke sensor can be easily adjusted using a simple process. The method has the steps of; obtaining a relationship between the magnetic field and the indicator value while moving the magnet in the first direction relative to the magnetic field detecting element within a predetermined relative movable range, and writing the relationship in the processor; after the relationship is written in the processor, preventing the predetermined relative movable range from being shifted in the first direction by means of a jig for preventing positional shift, wherein the jig includes an element that fixes relative positions between the magnetic field detecting element and the magnet; attaching the magnet and the magnetic field detecting element, which have been prevented from being shifted, to different structures that are movable in the first direction relative to each other, and removing the jig.

Easily adjustable stroke sensor and method for installing the same

A position detection device includes a magnetic scale and a magnetic sensor. The magnetic scale includes a plurality of magnets arranged along a first reference direction. The magnetic sensor includes a plurality of detectors that detect a composite magnetic field. The plurality of detectors are each arranged to satisfy AG=N(M&#x2212;W)/(n&#x2212;1), where n is the number of magnets of the magnetic scale, M is a distance from a first end to a second end, W is the width of each of the plurality of magnets and is greater than 0 and less than or equal to M/n, AG is a gap between each of the plurality of magnets and each of the plurality of detectors in a second reference direction, and N is a number greater than or equal to 0.4 and less than or equal to 2.

A method of installing a stroke sensor that enables the stroke sensor to be adjusted in a simple process is provided. The method has the steps of: arranging a second magnet, relative to the magnetic field detecting element, at a physically determinable first reference position and obtaining an indicator value S1; attaching the first magnet and the magnetic field detecting element to structures different from each other, respectively, and positioning the first magnet, relative to the magnetic field detecting element, at a physically determinable second reference position, and obtaining an indicator value S2, wherein the second reference position corresponds to the first reference position; calculating &#x394;S=S1&#x2212;S2, wherein &#x394;S is a difference between the indicator value S1 and the indicator value S2; and modifying a process in the processor such that a sum of the indicator value S and &#x394;S is outputted.

A position sensor is provided that can detect a position along a long stroke and that can limit an increase in size. A magnetic sensor has a first magnetic field detecting element that is positioned in a first track; a first processorA that outputs voltage VMwhen intensity of a first magnetic field that is applied to the first magnetic field detecting element is equal to or larger than a threshold and that outputs predetermined high voltage VH when the intensity of the first magnetic field is less than the threshold, wherein the voltage VMis voltage between predetermined low voltage VL and the high voltage VH and indicates positions of the magnets relative to the first magnetic field detecting element; a second magnetic field detecting element that is positioned in a second track; and a second processorB that outputs the low voltage VL when intensity of a second magnetic field that is applied to the second magnetic field detecting element is less than the threshold and that outputs voltage VMwhen the intensity of the second magnetic field is equal to or larger than the threshold, wherein the voltage VMis voltage between the low voltage VL and the high voltage VH and indicates positions of the magnets relative to the second magnetic field detecting element.

Growing community of inventors

Tokyo, Japan

Toshio Ishikawara