JP2015095642A5

JP2015095642A5 -

Info

Publication number: JP2015095642A5
Application number: JP2013244364A
Authority: JP
Filing date: 2013-11-08
Publication date: 2016-12-01
Anticipated expiration: 2033-11-08

Description

Magnet, measuring method and magnetizing apparatus

本発明は回転軸の回転角を検出する回転角センサ、並びに磁石とセンサ間の距離を検出する位置センサに利用可能な磁石、測定方法及び着磁装置に関する。 The present invention is a rotation angle sensor, as well as the available magnet position sensor for detecting the distance between the magnet and the sensor for detecting the rotation angle of the rotary shaft, about the measuring method and magnetizing apparatus.

従来、回転軸の回転角・回転速度を検出する回転角センサは回転軸端に取り付けた磁石へ回転軸に対し直角方向に２極以上、あるいは、回転軸方向に対し互いに１８０度、方向の異なる２方向以上の着磁（所謂面着磁）を施し、磁石の周囲に配置した磁気センサにより、回転軸の回転に伴う磁束密度変化を捉えることにより回転角や回転速度を求めていた。このような回転角速度センサが特許文献１に記載されている。 Conventionally, a rotation angle sensor for detecting the rotation angle / rotation speed of the rotation shaft has two or more poles perpendicular to the rotation axis to the magnet attached to the end of the rotation shaft, or 180 degrees different from each other in the rotation axis direction. Two or more directions of magnetization (so-called surface magnetization) are applied, and a rotation angle and a rotation speed are obtained by capturing a change in magnetic flux density accompanying rotation of the rotation shaft by a magnetic sensor arranged around the magnet. Such a rotational angular velocity sensor is described in Patent Document 1.

また、磁石とセンサ間の距離を検出する場合は、特許文献４に記載されているような構成で、磁石又はセンサの移動に伴う空隙距離変動で変化する磁束密度をセンサで捉えて、磁束密度変動で変化するセンサ出力を観測することで空隙距離を求めていた。 In addition, when detecting the distance between the magnet and the sensor, the configuration described in Patent Document 4 is used, and the magnetic flux density that changes due to the gap distance variation accompanying the movement of the magnet or sensor is captured by the sensor. The gap distance was obtained by observing the sensor output that changed with the fluctuation.

特開２０１１−５８８７０号公報JP 2011-58870 A 特開２０１０−２７６５７４号公報JP 2010-276574 A 特開２００９−２７３７号公報JP 2009-2737 A 特開２００４−２７１４９５号公報JP 2004-271495 A

通常、センサの検出する磁束量は磁石の着磁面とセンサの感磁面間距離の２乗に反比例する。すなわち、回転角センサのあるいは位置センサとして、磁石とセンサを配置する際、その組立て誤差や部品寸法精度のバラつきによって発生する空隙距離の変動に対し、センサの検出する磁束変動量は大きくなる。従来より使用されてきたホール素子やサーチコイルといったセンサであれば、磁束の最小量がセンサを動作させるのに十分な量であれば良かったので、最大空隙量を管理すれば良かったが、近年使われ始めた磁束方向検出型センサは飽和特性を持っている場合が多いため、高磁束密度側にも動作不能領域がある。そのため、このようなセンサを使用する場合は空隙量の最大値と最小値を同時に管理する必要がある。 Usually, the amount of magnetic flux detected by the sensor is inversely proportional to the square of the distance between the magnetized surface of the magnet and the magnetically sensitive surface of the sensor. That is, when a magnet and a sensor are arranged as a rotation angle sensor or as a position sensor, the fluctuation amount of magnetic flux detected by the sensor becomes large with respect to fluctuations in the gap distance caused by variations in assembly errors and component dimensional accuracy. For sensors such as Hall elements and search coils that have been used in the past, it was sufficient if the minimum amount of magnetic flux was sufficient to operate the sensor. Since the magnetic flux direction detection type sensor which has begun to be used often has a saturation characteristic, there is an inoperable region on the high magnetic flux density side. Therefore, when using such a sensor, it is necessary to simultaneously manage the maximum value and the minimum value of the air gap amount.

本発明は、上記問題に鑑み成されたものであり、空隙変化に対する磁束量、あるいは磁束密度変化の小さい磁石を提供することにより、空隙量管理の負担を軽減することを目的とする。 The present invention has been made in view of the above problems, and an object of the present invention is to reduce the burden of air gap amount management by providing a magnet having a small amount of magnetic flux with respect to air gap changes or a change in magnetic flux density.

上記課題を解決するために図２に示すような構造の着磁ヨークを使用し、磁石を着磁する。
このヨークは、着磁面の中心に着磁される磁石の着磁領域の幅より十分に狭い領域で、２極に着磁するための着磁面である中央部着磁領域を着磁するヨークのポールピースｅと、ｅより広い領域で隣り合うｅ領域とは逆の極性を着磁する外側着磁領域を着磁するヨークのポールピースｆとで構成される。 In order to solve the above problem, a magnetized yoke having a structure as shown in FIG. 2 is used to magnetize the magnet.
The yoke is sufficiently narrow region than the width of the magnetized areas of magnets magnetized in the center of the magnetized face, magnetizing central portion magnetized areas are magnetized surface for magnetizing the two poles and the pole piece e of the yoke, and a pole piece f of the yoke for magnetizing the outer magnetization region that magnetizing polarities opposite to that of the e region adjacent a wider than e region.

このヨーク構造により、磁石着磁面は中央部の狭い領域にＮ−Ｓ１対の極と、その外側の広い領域に中央部とは逆の極性を持つＳ−Ｎ１対の極の計４極が着磁される。すると、図１のように、磁石着磁面上には磁石に近い領域では中央部着磁領域により発生する磁力線ｃ方向の磁束、磁石から遠い領域ではｃ方向とは逆の外側着磁領域により発生する磁力線ｄ方向の磁束が発生する。
つまり、磁気センサを用い磁石との空隙距離を変化させながら、磁束や磁束密度を観測すると、図３のようにある点で磁束の方向が反転する磁束・磁束密度分布が観測される。と同時に、磁束・磁束密度量は図４実線のように、磁束反転域より少し離れて、その変化量が少ない領域が観測される。 With this yoke structure, the magnet magnetized surface has a total of four poles, a pair of N-S1 poles in a narrow area at the center and a pair of S-N1 poles having a polarity opposite to the center in a wide area outside. Magnetized. Then, as shown in FIG. 1, on the magnet magnetized surface, a magnetic flux in the direction c of the magnetic field generated by the central magnetized region in the region close to the magnet, and an outer magnetized region opposite to the c direction in the region far from the magnet. A magnetic flux in the direction of the generated magnetic force line d is generated.
That is, when the magnetic flux and the magnetic flux density are observed while changing the gap distance from the magnet using the magnetic sensor, a magnetic flux / magnetic flux density distribution in which the direction of the magnetic flux is reversed at a certain point as shown in FIG. 3 is observed. At the same time, as shown by the solid line in FIG. 4, a region where the amount of change is small is observed slightly apart from the magnetic flux reversal region.

磁束の反転する空隙距離調整の手段の１つはヨーク中央部の狭領域の幅を調整することであるが、この領域を広げすぎると、着磁された磁石で隣り合う極間でのみ磁束が発生し、中央の極対を飛び越える磁束が生じないので、注意が必要である。 One of the means for adjusting the gap distance where the magnetic flux is reversed is to adjust the width of the narrow region in the central part of the yoke. Care must be taken because no magnetic flux is generated and jumps over the center pole pair.

別の磁束反転の空隙距離調整手段としては、着磁ヨーク中央部コイル線の着磁面からの深さを変えることで着磁ヨーク中央部の発生磁界を制御できるので、これを利用する。
また、外側着磁領域ｂを大きく取る、コイル巻線数を調整する、中央部着磁領域ａでの発生磁界を制御する電流量と、外側着磁領域ｂの発生磁界を制御する電流量とを個別に制御する手段もある。 Another air gap distance adjusting means for reversing the magnetic flux is used because the magnetic field generated in the central part of the magnetized yoke can be controlled by changing the depth from the magnetized surface of the coil wire in the central part of the magnetized yoke.
Further, a large outer magnetization region b, adjusting the number of coil windings, the current amount for controlling the generated magnetic field at the center magnetic areas a, a current amount for controlling the magnetic field generated by the outer magnetization region b There is also a means for individually controlling.

したがって、本発明の磁石は着磁面に複数の着磁領域を有する磁石であって、前記着磁領域は、前記着磁面の中央部における前記磁石の厚さ方向の極性が互いに逆となる２極の中央部着磁領域と、前記中央部着磁領域の外側に配し、前記中央部着磁領域より面積が広く、かつ前記磁石の厚さ方向の極性が隣接する極と逆になるように前記着磁領域が分割された外側着磁領域を備え、前記中央部着磁領域の面積は前記着磁面の面積の５０％を超えないよう構成することを特徴とする。Therefore, the magnet of the present invention is a magnet having a plurality of magnetized regions on the magnetized surface, and the magnetized regions have opposite polarities in the thickness direction of the magnet at the center of the magnetized surface. A two-pole central magnetized region and an outer side of the central magnetized region, having a larger area than the central magnetized region, and the polarity in the thickness direction of the magnet is opposite to the adjacent pole In this manner, the magnetized region is divided into outer magnetized regions, and the area of the central magnetized region does not exceed 50% of the area of the magnetized surface.

また、本発明の測定方法は、前記磁石が、前記着磁面に対し平行方向に感度を有する磁気センサを前記着磁面と対向させて離間配置し、前記磁石を回転させて前記磁気センサの出力の変動を検出することにより、前記着磁面と前記磁気センサの間の回転角、空隙距離を測定することを特徴とする。In the measuring method of the present invention, the magnet may be arranged with a magnetic sensor having sensitivity in a direction parallel to the magnetized surface facing the magnetized surface and spaced apart, and the magnet may be rotated to rotate the magnet sensor. A rotation angle and a gap distance between the magnetized surface and the magnetic sensor are measured by detecting a change in output.

また、本発明の着磁装置は、磁石の着磁面を複数の領域に着磁するヨークと、前記ヨークを励磁する複数のコイルを備える着磁装置であって、着磁する前記複数の領域の中央部における前記磁石の厚さ方向の極性が互いに逆となる２極の中央部着磁領域と、前記中央部着磁領域の外側に配し、前記中央部着磁領域より面積が広く、かつ前記磁石の厚さ方向の極性が隣接する極と逆になるように前記複数の領域を分割した外側着磁領域を備え、前記中央部着磁領域の面積は前記着磁面の面積の５０％を超えないよう構成することを特徴とする。The magnetizing device of the present invention is a magnetizing device comprising a yoke for magnetizing a magnetized surface of a magnet in a plurality of regions, and a plurality of coils for exciting the yoke, wherein the plurality of regions to be magnetized. The central magnetized region of two poles in which the polarities in the thickness direction of the magnet in the central part of the magnet are opposite to each other, and the outside of the central magnetized region, the area is wider than the central magnetized region, And an outer magnetized region in which the plurality of regions are divided so that the polarity in the thickness direction of the magnet is opposite to the adjacent pole, and the area of the central magnetized region is 50 times the area of the magnetized surface. It is characterized by comprising so that it may not exceed%.

また、本発明の着磁装置では、前記ヨークは、着磁する前記複数の領域に対応するポールピースを備え、各々の前記ポールピースの幅を変えることによって、前記磁石の着磁する前記複数の領域の面積を変えることを特徴とする。In the magnetizing apparatus of the present invention, the yoke includes pole pieces corresponding to the plurality of regions to be magnetized, and the plurality of magnets magnetized by changing the width of each of the pole pieces. It is characterized by changing the area of the region.

ヨークのポールピースの幅を変えることにより、着磁される磁石の着磁面−センサ間空隙距離−磁束密度特性を制御することができる。By changing the width of the pole piece of the yoke, the magnetized surface of the magnet to be magnetized—the gap distance between the sensors—the magnetic flux density characteristic can be controlled.

また、ヨークの着磁面とコイルの位置関係を変えることにより、着磁される磁石の着磁面−センサ間空隙距離−磁束密度特性を制御する着磁を行うことができる。Further, by changing the positional relationship between the magnetized surface of the yoke and the coil, it is possible to perform magnetization for controlling the magnetized surface of the magnet to be magnetized, the gap distance between the sensors, and the magnetic flux density characteristics.

また、着磁装置におけるコイル巻線数、あるいはコイル電流の制御により、着磁される磁石の着磁面−センサ間空隙距離−磁束密度特性を制御する着磁を行うことができる。Further, by controlling the number of coil windings or the coil current in the magnetizing device, it is possible to perform magnetization for controlling the magnetized surface of the magnet to be magnetized, the gap distance between the sensors, and the magnetic flux density characteristics.

本発明により、磁石着磁面と磁気センサ間の空隙距離を縮めても、センサの検出する磁束密度に上限値を設定可能で有り、空隙距離管理の負荷を軽減することが可能となる。 According to the present invention, even if the gap distance between the magnetized surface and the magnetic sensor is shortened, an upper limit value can be set for the magnetic flux density detected by the sensor, and the gap distance management load can be reduced.

本発明に係わるセンサと磁石、及びその磁力線の位置関係図である。 It is a position relation figure of a sensor concerning the present invention, a magnet, and its magnetic field line . 本発明に係わる着磁ヨークの基本構造図である。 It is a basic structure figure of the magnetizing yoke concerning the present invention . 本発明に係わる磁石着磁面上の磁束ベクトル分布図である。 It is a magnetic flux vector distribution map on the magnet magnetization surface concerning the present invention . 本発明に係わる磁石・センサ間空隙距離−磁束密度特性図である。 It is a magnet-sensor gap distance-magnetic flux density characteristic view concerning the present invention . 本発明に係わる磁石回転に伴う磁束密度変化図である。 It is a magnetic flux density change figure accompanying magnet rotation concerning the present invention . 本発明に係わる着磁ヨーク実施例図である。 It is an example figure of a magnetizing yoke concerning the present invention . 本発明に係わる磁石の磁極分布図である。 It is a magnetic pole distribution map of the magnet concerning the present invention . 従来技術の着磁ヨーク構造図である。 It is a magnetized yoke structure figure of a prior art .

着磁ヨーク構造として、図６に示すように中央部に１．８ｍｍ間隔で３箇所にコイル溝を配し、２極の着磁に対応させたポールピースとする。各々のポールピースには、径１ｍｍのコイル線が２巻分巻かれた状態にし、このコイル溝の中心溝から左右に１０ｍｍ離れた位置にもコイル溝を設ける。 As shown in FIG. 6 , the magnetized yoke structure has a pole piece corresponding to two-pole magnetization by arranging coil grooves at three locations at an interval of 1.8 mm in the central portion. Each pole piece has a coil wire having a diameter of 1 mm wound in two turns, and a coil groove is provided at a position 10 mm away from the center groove of the coil groove.

中心部のコイル溝群端部の溝とその外側に設けたコイル溝とで構成するポールピースには１巻相当のコイル線を巻き、コイルに電流を流した際に発生する磁気極性は隣り合うポールピースに発生する磁気極性とは逆の極性となるように巻線する。 A pole piece composed of a groove at the end of the coil groove group in the center and a coil groove provided outside the coil groove is wound with a coil wire equivalent to one turn, and the magnetic polarities generated when a current is passed through the coil are adjacent to each other. The winding is performed so that the polarity is opposite to the magnetic polarity generated in the pole piece.

この着磁ヨークの中央部に直径１２ｍｍ厚さ５ｍｍの厚さ方向に配向させた最大エネルギー積１６ｋＪ／ｍ^３のフェライトプラスチック磁石を密着させ、最大電流１０ｋＡの瞬間電流を流して着磁すると、磁石は図７のような極性分布を持つ磁石となる。 When a ferrite plastic magnet having a maximum energy product of 16 kJ / m ³ oriented in the thickness direction with a diameter of 12 mm and a thickness of 5 mm is brought into close contact with the central portion of the magnetized yoke, and magnetized by passing an instantaneous current of a maximum current of 10 kA, Becomes a magnet having a polarity distribution as shown in FIG.

こうして着磁された磁石の着磁面上にその面に対し平行方向に感度を持つホール素子等の磁気センサを置き、磁石を回転させるとセンサからの出力は正弦波に近似するが、その出力最大値を磁石着磁面と磁気センサ間の空隙距離毎にプロットすると、出力特性曲線は図４実線のように空隙距離の変動に対してセンサ出力変動の小さい領域が認められる形となる。 When a magnetic sensor such as a Hall element having sensitivity in the direction parallel to the magnet surface is placed on the magnetized surface of the magnet thus magnetized and the magnet is rotated, the output from the sensor approximates a sine wave. When the maximum value is plotted for each gap distance between the magnetized surface and the magnetic sensor, the output characteristic curve has a shape where a sensor output fluctuation is small with respect to the gap distance fluctuation as shown by the solid line in FIG.

参考までに通常製作される図８のような標準的着磁ヨークを用いて、上記記述と同形状、同素材、同特性の磁石を同じ最大電流１０ｋＡで着磁した場合のセンサ−磁石間空隙距離出力特性は図４破線のようになり、本発明の実施例と比べると、空隙距離変動に対するセンサ出力変動の安定する領域は認められない。 For reference, a standard magnetized yoke as shown in FIG. 8 is used, and a sensor-to-magnet gap is obtained when a magnet having the same shape, material and characteristics as described above is magnetized at the same maximum current of 10 kA. The distance output characteristic is as shown by a broken line in FIG. 4, and a region where the sensor output fluctuation is stable with respect to the gap distance fluctuation is not recognized as compared with the embodiment of the present invention.

出力安定域の空隙距離、出力絶対値はコイル間隔の調整や磁石素材の選択により調整可能であり、使用する磁気センサの特性に合わせることが可能である。 The gap distance and the output absolute value in the stable output range can be adjusted by adjusting the coil interval or selecting the magnet material, and can be adjusted to the characteristics of the magnetic sensor used.

ａ中央部着磁領域
ｂ外側着磁領域
ｃ中央部着磁領域により発生する磁力線
ｄ外側着磁領域により発生する磁力線
ｅ中央部着磁領域を着磁するヨークのポールピース
ｆ外側着磁領域を着磁するヨークのポールピース
ＮＮ極を示す
ＳＳ極を示す a center magnetized region b outer magnetized region c magnetic field lines generated by the central magnetized region d magnetic field lines generated by the outer magnetized region e pole piece of the yoke magnetizing the central magnetized region f outer magnetized region Pole piece of magnet to be magnetized N Indicates N pole S Indicates S pole

Claims

A magnet having a plurality of magnetized regions on a magnetized surface, wherein the magnetized region is magnetized in a central part of two poles in which the polarities in the thickness direction of the magnet are opposite to each other in the central part of the magnetized surface The magnetized region is disposed outside the region and the central magnetized region, has a larger area than the central magnetized region, and the magnetized region has a polarity opposite to the adjacent pole in the thickness direction of the magnet. A magnet comprising a divided outer magnetized region, wherein the area of the central magnetized region does not exceed 50% of the area of the magnetized surface.

A magnetic sensor having sensitivity in a parallel direction with respect to the magnetized surface of the magnet according to claim 1 is arranged so as to be opposed to the magnetized surface, and the magnet is rotated to change the output of the magnetic sensor. By detecting the rotation angle and the gap distance between the magnetized surface and the magnetic sensor.

A magnetizing device comprising a yoke for magnetizing a magnetized surface of a magnet in a plurality of regions, and a plurality of coils for exciting the yoke, wherein the magnet has a thickness direction in a central portion of the plurality of regions to be magnetized Are disposed on the outside of the central magnetized region, the area is larger than the central magnetized region, and the magnet has a polarity in the thickness direction. An outer magnetized region obtained by dividing the plurality of regions so as to be opposite to adjacent poles is provided, and the area of the central magnetized region is configured not to exceed 50% of the area of the magnetized surface. A magnetizing device.

The yoke includes a pole piece corresponding to the plurality of regions to be magnetized, and the area of the plurality of regions to which the magnet is magnetized is changed by changing a width of each of the pole pieces. The magnetizing apparatus according to claim 3.