Hitachi Metals, Ltd.

Jtekt Corporation

Hitachi Cable, Inc.

Ken Okuyama

Naoki Futakuchi

Katsuya Akimoto

Yujiro Tomita

Jun Umetsu

Haruyasu Komano

Yukio Ikeda

Naofumi Chiwata

Kazuhisa Takahashi

Takahiro Futatsumori

Takahiro Sanada

Hisashi Tate

Yukitoshi Terasaka

Shinya Hayashi

Masaki Noguchi

A current sensor includes a bus bar in which a current to be detected flows, a circuit board mounted with a magnetic detection element thereon to detect a strength of a magnetic field generated by a current flowing in the bus bar, and a housing including first and second housings provided in such a manner as to sandwich the bus bar and the circuit board therebetween in a plate thickness direction of the bus bar. The first and second housings include slide guide portions respectively which are relatively slidable in a sloping direction with respect to the plate thickness direction of the bus bar while abutting each other in the plate thickness direction of the bus bar.

Current sensor

A current sensor includes three bus bars arranged in such a manner to be spaced and aligned in a width direction thereof. A first shield plate and a second shield plate, which are made of a magnetic material, are arranged in such a manner to sandwich the three bus bars therebetween together in a thickness direction perpendicular to the width direction. Three magnetic detection elements are arranged between the three bus bars respectively and the first shield plate to detect a magnetic field strength generated by currents flowing through the corresponding bus bars. A conductive plate is disposed between each of the magnetic detection elements and the first shield plate. The conductive plate is disposed in such a manner to sandwich the three bus bars together between the conductive plate and the second shield plate. The conductive plate is made of a nonmagnetic conductive material.

A current sensor includes first and second bus bars aligned and arranged in such a manner to be spaced from each other in a plate width direction, a third bus bar arranged in such a manner that a plate thickness direction thereof coincides with a plate thickness direction of the first and second bus bars and a length direction thereof is orthogonal to a length direction of the first and second bus bars, first and second magnetic detection elements arranged opposite the first and second bus bars respectively in the plate thickness direction, and a third magnetic detection element arranged opposite the third bus bar in the plate thickness direction. The first and second magnetic detection elements are gradient detection type magnetic detection elements and are arranged in such a manner that a detection axis direction thereof is perpendicular to the length direction of the first and second bus bars and is tilted with respect to the plate thickness direction of the first and second bus bars. The third magnetic detection element is arranged in such a manner that a detection axis direction thereof coincides with a plate width direction of the third bus bar.

A current sensor includes a bus bar through which a measured current is carried, a pair of shielding plates that include a magnetic material, and are arranged to sandwich the bus bar in a thickness direction of the bus bar, and a magnetic detection element that is arranged between the bus bar and one of the shielding plates, and detects an intensity of magnetic field caused by the current carried through the bus bar. The shielding plate has a length of not less than 20 mm in a length direction of the bus bar, and a width of not less than 24 mm and not more than 38 mm in a width direction orthogonal to the length direction.

A current sensor includes plural bus bars which are each formed rectangular in a cross section, a pair of shield plates that include a magnetic material and are arranged so as to collectively sandwich the plural bus bars therebetween, and plural magnetic detection elements that are each arranged between the bus bars and one of the shield plates. A distance d between a detection position of a magnetic field intensity at an arbitrary one of the magnetic detection elements and a center position in the width direction between one of the bus bars corresponding to the arbitrary magnetic detection element and an other of the bus bars adjacent thereto in the width direction satisfies the following expression: d/w+0.023(w/h)&#x2265;0.36 where a width of the shield plates is w and an interval along a height direction of the shield plates is h.

A current sensor includes two bus bars, each of which is formed in a plate shape, the two bus bars being aligned and arranged so as to be spaced apart from each other in a plate width direction thereof, and magnetic detection element arranged opposite the two bus bars, respectively, in a plate thickness direction of the bus bars to detect a magnetic field strength generated by a current flowing through the corresponding bus bars. The magnetic detection element are gradient detection type magnetic detection elements that output a difference between magnetic field strengths detected at two magnetic sensing positions, respectively, and are arranged in such a manner that a detection axis direction thereof is perpendicular to a length direction of the bus bars and is tilted with respect to the plate thickness direction.

An electric current detection device includes magnetism detector elements for detecting a strength of a magnetic field generated by an electric current flowing through an electric current path, a detection circuit for detecting a magnitude of an electric current flowing through the electric current path based on an output of the magnetism detector elements, and plural wires that are connected to the magnetism detector elements and extend in a direction away from the electric current path. The magnetism detector elements are arranged such that a direction of a magneto-sensitive axis thereof lies on a first plane parallel to a current-carrying direction of the electric current path and parallel to an extending direction of the plurality of wires. The plural wires are arranged on a same plane of a second plane orthogonal to the first plane.

Electric current detection device and electric current detection method

A current sensor includes a bus bar through which an electric current to be measured flows, a first magnetic sensing element including a first magneto-sensitive portion including a magneto-resistive element, and a second magnetic sensing element including a second magneto-sensitive portion including a magneto-resistive element. Strength of a magnetic field generated by the electric current sensed by the first magneto-sensitive portion is different from a strength of the magnetic field sensed by the second magneto-sensitive portion. A first bias magnetic field is applied to the first magneto-sensitive portion and a second bias magnetic field in a direction opposite to a direction of the first bias magnetic field is applied to the second magneto-sensitive portion.

A current sensor includes, a bus bar through which a current flows, a magnetic detection element detecting a magnetic field intensity generated by the current, first and second shielding plates arranged so as to sandwich the bus bar between the first and second shielding plates, a first conductive plate made of a conductive nonmagnetic material, arranged between the bus bar and the first shielding plate, and a second conductive plate made of the conductive nonmagnetic material, arranged between the bus bar and the second shielding plate, wherein the magnetic detection element is arranged at a first conductive plate-side. A distance between the first conductive plate and the bus bar is longer than a distance between the second conductive plate and the bus bar. The first conductive plate includes a slit formed in the first conductive plate at an overlapping position, and the slit pierces the first conductive plate.

A current sensor includes a busbar carrying an electric current to be measured, a magnetic sensing element for detecting intensity of a magnetic field generated by the current flowing through the busbar, and a pair of shield plates that include magnetic materials and are arranged to sandwich the busbar in a thickness direction of the busbar. The shield plates include a conductive shield plate including a conductive magnetic material and a non-conductive shield plate including a non-conductive magnetic material. The conductive shield plate includes a slit penetrating therethrough. The magnetic sensing element is arranged at a position where the magnetic sensing element overlaps the slits in the thickness direction and does not overlap the conductive shield plate in the thickness direction.

A current sensor includes a busbar carrying an electric current to be measured, a magnetic sensing element for detecting intensity of a magnetic field generated by the current flowing through the busbar, and a pair of shield plates that include a magnetic material and are arranged to sandwich the busbar in a thickness direction of the busbar. The busbar includes a through-hole penetrating therethrough and current paths formed on both sides of the through-hole, the magnetic sensing element is arranged at a position overlapping the through-hole in the thickness direction of the busbar. The busbar is arranged in a space between the pair of shield plates such that the center in the thickness direction is located at a position offset from the center of the space in the thickness direction.

An electric current sensor includes a plurality of bus bars arranged in parallel, a plurality of magnetic detection elements that are adapted to detect a strength of a magnetic field generated by an electric current flowing through the bus bars and to output a voltage according to the strength of the magnetic field detected, and an arithmetic operation part to arithmetically operate an electric current flowing through the bus bars based on the voltage output from the plurality of magnetic detection elements. The arithmetic operation part includes a magnetic flux density arithmetic operation part to arithmetically operate a magnetic flux density based on the voltage, and an electric current arithmetic operation part to arithmetically operate an electric current Ito Iflowing through each of the bus bars based on formula (1) below, Bto Bare a magnetic flux density and Ito Iare an electric current.

Electric current sensor

A current detection structure includes a plurality of busbars arranged in parallel, and a plurality of magnetic detection elements each provided for corresponding one of the plurality of busbars so as to measure a strength of a magnetic field generated by a current flowing through the corresponding busbar. The plurality of magnetic detection elements are mounted on a single circuit board.

Current detection structure

A current detection structure includes a busbar to flow a current therethrough, a magnetic detection element to detect a strength of a magnetic field generated by the current flowing through the busbar, and a current detecting portion to determine the current flowing through the busbar based on the magnetic field detected by the magnetic detection element. A through-hole is formed penetrating the busbar such that a current path is formed on both sides of the through-hole. The magnetic detection element is disposed in the through-hole. The current detecting portion determines the current flowing through the busbar based on a strength of a synthetic magnetic field detected by the magnetic detection element. The synthetic magnetic field is produced by combining a magnetic field that is generated by a current flowing through the current path on the both sides of the through-hole.

A cable holding structure includes a plate-shaped member having an opening, and a conductive wire holding portion holding a plurality of wires inserted therethrough, the wire holding portion being disposed in the opening and electrically connected to a braided shield that collectively covers the plurality of wires. The wire holding portion protrudes from the opening of the plate-shaped member and includes a plurality of through-holes extending in a direction orthogonal to the plate-shaped member. The plurality of wires are each enclosed in the through-holes. The braided shield is electrically connected to an outer surface of the wire holding portion protruding from the opening.

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Hitachi, Japan

Ken Okuyama