JP2009025163A - Magnetic encoder - Google Patents

Magnetic encoder Download PDF

Info

Publication number
JP2009025163A
JP2009025163A JP2007188729A JP2007188729A JP2009025163A JP 2009025163 A JP2009025163 A JP 2009025163A JP 2007188729 A JP2007188729 A JP 2007188729A JP 2007188729 A JP2007188729 A JP 2007188729A JP 2009025163 A JP2009025163 A JP 2009025163A
Authority
JP
Japan
Prior art keywords
pole
poles
wide
magnetic
uniform
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2007188729A
Other languages
Japanese (ja)
Inventor
Yasushi Sugiyama
靖 杉山
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nok Corp
Original Assignee
Nok Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nok Corp filed Critical Nok Corp
Priority to JP2007188729A priority Critical patent/JP2009025163A/en
Publication of JP2009025163A publication Critical patent/JP2009025163A/en
Pending legal-status Critical Current

Links

Images

Landscapes

  • Transmission And Conversion Of Sensor Element Output (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic encoder capable of enhancing precision of a pulse pitch of a magnetic flux waveform of magnetic poles arranged at equal pitches in the vicinity of a reference point without being affected by a gap length of a detecting sensor. <P>SOLUTION: The magnetic encoder 1 is provided with a magnetized pattern having equal-arrangement poles 11 so configured that N poles and S poles are alternately provided at an equal arrangement pitch and one or more wide-width poles 12 which are disposed adjacent to the equal-arrangement poles 11, each width of the poles 12 being greater than the pitch of the equal-arrangement poles 11. The equal-arrangement poles 11 and the wide-width poles 12 are provided on a surface of a ring-shaped rotor 10 rotatable with respect to a detecting means 20 for detecting intensity of a magnetic field. An absorption pole 14 having a width smaller than the pitch of the equal-arrangement poles 11 and a polarity opposite to that of the wide-width pole 12 is provided to a portion in the vicinity of the end of the equal-arrangement poles 11 adjacent to the wide-width pole 12. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は磁気エンコーダに関し、詳しくは、Ｎ極とＳ極を交互に設けた等配極を有する環状のロータに、基準点を構成する１つ以上の幅広極を有する磁気エンコーダに関する。   The present invention relates to a magnetic encoder, and more particularly, to a magnetic encoder having one or more wide poles constituting a reference point on an annular rotor having equipolar poles in which N poles and S poles are alternately provided.

従来、環状のロータの表面にＮ極とＳ極の磁極を等配ピッチで交互に配置した多極エンコーダは、自動車エンジンのクランク角検出用途等に利用されている。特にクランク角検出用エンコーダの場合、上死点（ＴＤＣ）等の基準点を検出するために、図４に示すように、等配ピッチで交互に配置されるＮ極とＳ極の磁極１０１の他に、この磁極１０１よりも幅広とした幅広極１０２を設け、この幅広極１０２を含むように基準点１００を形成し、これを検出することにより基準位置の検出を行うようにしている。   2. Description of the Related Art Conventionally, multipolar encoders in which N-pole and S-pole magnetic poles are alternately arranged at an equal pitch on the surface of an annular rotor have been used for detecting the crank angle of an automobile engine. In particular, in the case of an encoder for detecting a crank angle, in order to detect a reference point such as a top dead center (TDC), as shown in FIG. 4, N poles and S poles 101 are alternately arranged at a uniform pitch. In addition, a wide pole 102 wider than the magnetic pole 101 is provided, a reference point 100 is formed so as to include the wide pole 102, and the reference position is detected by detecting this.

この基準点１００は、図５に示すように、極性の異なる２つの幅広極１０２Ａ、１０２Ｂによって形成される場合もある。   As shown in FIG. 5, the reference point 100 may be formed by two wide poles 102A and 102B having different polarities.

しかしながら、このように基準位置を検出するために幅広極を設けた磁気エンコーダでは、該幅広極の磁束密度分布が、その他の等配ピッチで配置される磁極の磁束密度分布と異なるため、幅広極に隣接する等配ピッチの磁極において検出される磁束波形が乱れ、検出センサのギャップ長により検出誤差を招き易い問題がある。   However, in such a magnetic encoder provided with a wide pole for detecting the reference position, the magnetic flux density distribution of the wide pole is different from the magnetic flux density distribution of magnetic poles arranged at other equal pitches. There is a problem that the magnetic flux waveform detected in the magnetic poles with the equal pitch adjacent to the magnetic field is disturbed and a detection error is likely to be caused by the gap length of the detection sensor.

図６は、図４に示した構成からなる磁気エンコーダの基準点１００の近傍の磁束密度を検出センサのギャップ長を変えて測定した結果を示すグラフである。これに示されるように、主に幅広極１０２に隣接する等配ピッチの磁極１０１の波形のゼロクロスするポイント（検出される電圧値が０Ｖとなる点）がギャップ長１ｍｍの場合に対してギャップ長２ｍｍの場合ではずれてしまい、検出される波形にピッチ誤差があることが判る。これは幅広極１０２の近傍の磁束密度分布が乱れていることに由来する。   FIG. 6 is a graph showing a result of measuring the magnetic flux density near the reference point 100 of the magnetic encoder having the configuration shown in FIG. 4 while changing the gap length of the detection sensor. As shown in this figure, the gap length is compared with the case where the zero-crossing point (the point at which the detected voltage value is 0V) of the waveform of the magnetic pole 101 with the equal pitch adjacent to the wide pole 102 is a gap length of 1 mm. In the case of 2 mm, it is shifted, and it can be seen that the detected waveform has a pitch error. This is because the magnetic flux density distribution in the vicinity of the wide pole 102 is disturbed.

従来、このような問題に対し、基準点となる磁極を溝状に形成する技術（特許文献１）、基準点の着磁を不規則に形成する技術（特許文献２）、基準点となる磁極の中央に磁化しない領域を設ける技術（特許文献３）等が提案されている。
特許第３３１１４２９号公報 特開２００３−７５１９２号公報 特開２００５−６２１８９号公報 特許第３４２０５９３号公報 特開２００７−２４８８７号公報 Conventionally, with respect to such problems, a technique for forming a magnetic pole serving as a reference point in a groove shape (Patent Document 1), a technique for forming irregular magnetization of the reference point (Patent Document 2), and a magnetic pole serving as a reference point A technique of providing a non-magnetized region at the center of the above (Patent Document 3) has been proposed.
Japanese Patent No. 3311429 JP 2003-75192 A JP 2005-62189 A Japanese Patent No. 3420593 JP 2007-24887 A

しかしながら、特許文献１記載の技術では、溝加工位置と着磁位置との位置合わせが難しい問題がある。   However, the technique described in Patent Document 1 has a problem that it is difficult to align the groove processing position and the magnetizing position.

また、特許文献２記載の技術では、不規則な領域の着磁を行うことが難しい問題がある。例えば、特許文献４には磁気エンコーダに着磁を行うための回転式の着磁装置が開示されており、着磁を行う場合に有効であるが、不規則な領域の着磁は、このような回転式の着磁装置を用いて行うことができない問題がある。   Further, the technique described in Patent Document 2 has a problem that it is difficult to magnetize an irregular region. For example, Patent Document 4 discloses a rotary magnetizing device for magnetizing a magnetic encoder, which is effective when magnetizing, but the irregular region is magnetized in this way. There is a problem that cannot be performed using a simple rotating magnetizer.

更に、特許文献３記載の技術では、基準点の磁極中に磁化しない領域を設けることが困難な問題がある。すなわち、着磁は、通常、一方極の磁化を行えば、その隣接部ではもう一方の極を呈するので、磁化されない部分を作るには、この磁化したくない部分の着磁の程度に合わせて、これを打ち消すように逆の極の磁化を施し、部分的な消磁を行うことになる。そして、このためには、着磁状態の検出を行い、磁化されない部分の着磁の程度に合わせた異なる条件の着磁を複数回行うことが必要となり、着磁作業が煩雑化する問題がある。   Furthermore, the technique described in Patent Document 3 has a problem that it is difficult to provide a non-magnetized region in the magnetic pole at the reference point. That is, normally, if magnetization of one pole is performed, the other pole exhibits the other pole. Therefore, in order to create a non-magnetized part, it is necessary to match the degree of magnetization of the part that is not desired to be magnetized. In order to cancel this, magnetization of the opposite pole is performed and partial demagnetization is performed. For this purpose, it is necessary to detect the magnetization state and perform magnetization under different conditions in accordance with the degree of magnetization of the non-magnetized portion a plurality of times, which complicates the magnetizing operation. .

なお、特許文献５には、基準点を、等配ピッチの磁極と異なる不規則なピッチで形成し、この基準点を互いに離間する２つの検出センサによって検出する技術が開示されているが、上述の問題を解決するものではない。   Patent Document 5 discloses a technique in which the reference points are formed at irregular pitches different from the magnetic poles of the equal pitch, and the reference points are detected by two detection sensors separated from each other. It does not solve the problem.

そこで、本発明は、基準点近傍の等配ピッチの磁極の磁束波形のパルスピッチ精度が向上し、更には検出センサのギャップ長の影響を受けることのない磁気エンコーダを提供することを課題とする。   Accordingly, it is an object of the present invention to provide a magnetic encoder that improves the pulse pitch accuracy of the magnetic flux waveform of magnetic poles with a uniform pitch near the reference point and is not affected by the gap length of the detection sensor. .

本発明の他の課題は、以下の記載によって明らかとなる。   The other subject of this invention becomes clear by the following description.

上記課題は、以下の各発明によって解決される。   The above problems are solved by the following inventions.

（請求項１）
磁界の強さを検出する検出手段に対して回転する環状の磁気ロータの表面に、Ｎ極とＳ極を等配ピッチで交互に設けた等配極と、前記等配極に隣接して該等配極のピッチよりも幅広な１つ以上の幅広極とを有する着磁パターンが設けられた磁気エンコーダにおいて、
前記幅広極に隣接する前記等配極との境界部から該幅広極側に所定角度離間した位置で該幅広極内に、該幅広極の極性と逆極性の緩衝極を前記等配極のピッチよりも幅狭状に設けたことを特徴とする磁気エンコーダ。 (Claim 1)
Uniform poles in which N poles and S poles are alternately provided at an equal pitch on the surface of an annular magnetic rotor that rotates relative to a detection means that detects the strength of the magnetic field, and adjacent to the uniform poles, In a magnetic encoder provided with a magnetized pattern having one or more wide poles wider than a uniform pole pitch,
A buffer pole having a polarity opposite to the polarity of the wide pole is disposed in the wide pole at a position spaced from the boundary with the uniform pole adjacent to the wide pole by a predetermined angle toward the wide pole. A magnetic encoder having a narrower width than that of the magnetic encoder.

（請求項２）
前記緩衝極は、前記幅広極に隣接する前記等配極との境界部から該等配極のピッチ分だけ離間した位置に設けられていることを特徴とする請求項１記載の磁気エンコーダ。 (Claim 2)
2. The magnetic encoder according to claim 1, wherein the buffer pole is provided at a position separated from a boundary portion with the uniform pole adjacent to the wide pole by a pitch of the uniform pole.

（請求項３）
前記緩衝極の幅は、前記等配極のピッチの１／２０〜１／３であることを特徴とする請求項１又は２記載の磁気エンコーダ。 (Claim 3)
3. The magnetic encoder according to claim 1, wherein a width of the buffer pole is 1/20 to 1/3 of a pitch of the uniform pole.

（請求項４）
前記幅広極の一方端にのみ前記等配極が隣接し、前記緩衝極が前記幅広極に１つだけ設けられており、
前記幅広極の幅は、前記等配極のピッチの２倍以上であることを特徴とする請求項１、２又は３記載の磁気エンコーダ。 (Claim 4)
The uniform pole is adjacent to only one end of the wide pole, and only one buffer pole is provided on the wide pole,
4. The magnetic encoder according to claim 1, wherein the width of the wide pole is at least twice the pitch of the uniform poles.

（請求項５）
前記幅広極の両端にそれぞれ前記等配極が隣接し、前記緩衝極が前記幅広極に２つ設けられており、
前記幅広極の幅は、前記等配極のピッチの３倍以上であることを特徴とする請求項１、２又は３記載の磁気エンコーダ。 (Claim 5)
The equal poles are adjacent to both ends of the wide pole, and two buffer poles are provided on the wide pole,
4. The magnetic encoder according to claim 1, wherein the width of the wide pole is at least three times the pitch of the uniform poles.

本発明によれば、基準点近傍の等配ピッチの磁極の磁束波形のパルスピッチ精度が向上し、更には検出センサのギャップ長の影響を受けることのない磁気エンコーダを提供することができる。   According to the present invention, it is possible to provide a magnetic encoder that improves the pulse pitch accuracy of the magnetic flux waveform of the magnetic poles with a uniform pitch near the reference point and is not affected by the gap length of the detection sensor.

以下、本発明の好ましい実施の形態について図面を用いて説明する。   Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

（第１の実施形態）
図１は、本発明に係る磁気エンコーダの第１の実施形態を示す要部斜視図である。 (First embodiment)
FIG. 1 is a perspective view showing a main part of a first embodiment of a magnetic encoder according to the present invention.

同図において、磁気エンコーダ１は環状の磁気ロータ１０と、該磁気ロータ１０の表面から所定のギャップ長をおいて対向するように配置され、該磁気ロータ１０の回転によって発生する磁界の強さを検出する１つの検出手段２０を有している。検出手段２０には、本発明においては磁気センサが用いられる。磁気センサには一般にホール素子やＭＲ素子等が用いられる。   In the figure, a magnetic encoder 1 is arranged so as to oppose an annular magnetic rotor 10 with a predetermined gap length from the surface of the magnetic rotor 10, and the strength of a magnetic field generated by the rotation of the magnetic rotor 10 is determined. One detection means 20 for detection is provided. In the present invention, a magnetic sensor is used as the detection means 20. In general, a Hall element, an MR element, or the like is used for the magnetic sensor.

磁気ロータ１０の表面は、Ｎ極とＳ極を交互に配置した着磁パターンを有している。着磁パターンは、磁気ロータ１０の全周に亘ってＮ極とＳ極とが交互に配列されており、Ｎ極とＳ極の各磁極を等配ピッチ（磁極の円周方向の長さが等しいこと）で交互に設けた等配極１１と、この等配極１１に隣接して、該等配極１１のピッチ（幅）よりも幅広で、隣接する等配極１１とは逆極性となる１つの幅広極１２を有しており、この幅広極１２とこれに隣接する１つの等配極１１とによって基準点１３を形成している。   The surface of the magnetic rotor 10 has a magnetization pattern in which N poles and S poles are alternately arranged. In the magnetized pattern, N poles and S poles are alternately arranged over the entire circumference of the magnetic rotor 10, and the N poles and S poles are arranged at equal pitches (the length of the magnetic poles in the circumferential direction is different). The equal poles 11 are alternately provided, and adjacent to the uniform pole 11, wider than the pitch (width) of the uniform pole 11, and opposite in polarity to the adjacent uniform pole 11. The wide pole 12 and the single pole 11 adjacent to the wide pole 12 form a reference point 13.

なお、本発明における幅とは、磁気ロータ１０の円周方向の長さのことであり、この円周方向の長さは磁極角度によって規定される。   The width in the present invention is the length of the magnetic rotor 10 in the circumferential direction, and the length in the circumferential direction is defined by the magnetic pole angle.

ここでは、磁気ロータ１０の外形がφ９０ｍｍ、等配極１１のＮ極とＳ極の各磁極角度が３°、幅広極１２はＮ極とされ、その磁極角度が１５°とされ、基準点１３を構成する等配極１１はＳ極とされ、その磁極角度が３°とされているが、磁気ロータ１０の外形や各磁極の磁極角度は、適用される回転部材の径等の諸条件に応じて適宜決められる。   Here, the outer shape of the magnetic rotor 10 is φ90 mm, the magnetic pole angles of the N pole and S pole of the uniform pole 11 are 3 °, the wide pole 12 is N pole, the magnetic pole angle is 15 °, and the reference point 13 The magnetic pole 11 has a magnetic pole angle of 3 °. However, the outer shape of the magnetic rotor 10 and the magnetic pole angle of each magnetic pole depend on various conditions such as the diameter of the rotating member to be applied. It is decided accordingly.

これら等配極１１及び幅広極１２を形成する各磁極は、ゴムや樹脂製の磁性体を素材とすることが好ましく、フェライト粉又は希土類磁性粉をゴム又は樹脂中に充填成形し、これに着磁したものを好適に使用できる。   Each of the magnetic poles forming the uniform pole 11 and the wide pole 12 is preferably made of rubber or resin magnetic material, and ferrite powder or rare earth magnetic powder is filled and molded in rubber or resin. A magnetized one can be suitably used.

この実施形態では、幅広極１２に隣接する各等配極１１、１１との境界部ａから該幅広極１２側に所定角度離間した位置で該幅広極１２内に、該幅広極１２の極性と逆極性の（すなわちＳ極の）２つの緩衝極１４、１４が設けられている。   In this embodiment, the polarity of the wide pole 12 is set in the wide pole 12 at a position spaced by a predetermined angle from the boundary portion a between the uniform poles 11 and 11 adjacent to the wide pole 12 toward the wide pole 12. Two buffer poles 14 and 14 of opposite polarity (ie, S pole) are provided.

各緩衝極１４、１４の境界部ａからの位置（離間角度）は、該幅広極１２の両端部付近の磁束波形の乱れを好適に抑制できるようにする観点から、幅広極１２に隣接する等配極１１との境界部ａから該等配極１１のピッチ分だけ離間した位置とすることが好ましい。ここでは、各緩衝極１４、１４は境界部ａからそれぞれ等配極１１のピッチ分だけ離間した３°の角度をおいた位置に設けられている。   The positions (separation angles) of the buffer electrodes 14 and 14 from the boundary a are adjacent to the wide pole 12 from the viewpoint of suitably suppressing the disturbance of the magnetic flux waveform near both ends of the wide pole 12. It is preferable that the position is separated from the boundary portion a with the pole 11 by the pitch of the uniform pole 11. Here, each buffer pole 14 and 14 is provided in the position which set the angle of 3 degrees spaced apart from the boundary part a by the pitch of the equipolarity 11, respectively.

ここでは、緩衝極１４、１４の磁極角度はそれぞれ０．５°とされているが、各緩衝極１４、１４の幅は、広すぎると基準点１３の出力波形がゼロクロスする可能性が高くなって波形の誤検出を招くおそれが高くなり、また、狭すぎると本発明の目的である隣接する等配極１１のピッチ誤差を抑制しづらくなるため、等配極１１のピッチの１／２０〜１／３とすることが好ましく、より好ましくは１／１０〜１／４とすることである。   Here, the magnetic pole angles of the buffer poles 14 and 14 are 0.5 °, respectively. However, if the width of each buffer pole 14 and 14 is too wide, there is a high possibility that the output waveform of the reference point 13 zero-crosses. Therefore, if it is too narrow, it is difficult to suppress the pitch error of the adjacent uniform electrode 11 which is the object of the present invention. It is preferable to set to 1/3, more preferably 1/10 to 1/4.

また、本実施形態のように幅広極１２の両端にそれぞれ等配極１１が隣接し、このため緩衝極１４が幅広極１２内に２つ設けられている場合、基準点１３を確実に検出できるようにするため、各緩衝極１４、１４を含む幅広極１２の幅は、等配極１１のピッチの３倍以上とすることが好ましい。   In addition, when the equal poles 11 are adjacent to both ends of the wide pole 12 as in this embodiment, and two buffer poles 14 are provided in the wide pole 12, the reference point 13 can be reliably detected. For this reason, the width of the wide pole 12 including the buffer electrodes 14 and 14 is preferably set to be three times or more the pitch of the uniform poles 11.

かかる磁気エンコーダ１における基準点１３の近傍の波形出力は、図２に示すように、検出手段２０のギャップ長を異ならせた場合のピッチ誤差は軽減されており、隣接極への基準点１３の磁束密度の影響が軽減されていることがわかる。これは、幅広極１２の両端部付近の磁力線密度の乱れが、逆極性の緩衝極１４、１４の存在によって抑制されるためである。この波形出力において緩衝極１４、１４の検出部位Ａ、Ａのピークが下がっているが、ゼロクロスせず幅広極１２の一部として検出されるので問題とはならない。   As shown in FIG. 2, the waveform output in the vicinity of the reference point 13 in the magnetic encoder 1 reduces the pitch error when the gap length of the detection means 20 is varied, and the reference point 13 to the adjacent pole is reduced. It can be seen that the influence of the magnetic flux density is reduced. This is because the disturbance of the magnetic line density near the both ends of the wide pole 12 is suppressed by the presence of the buffer poles 14 and 14 having opposite polarities. In this waveform output, the peaks of the detection portions A and A of the buffer electrodes 14 and 14 are lowered, but this is not a problem because it is detected as a part of the wide electrode 12 without zero crossing.

従って、この磁気エンコーダ１によれば、基準点１３近傍の等配極１１の磁束波形のパルスピッチ精度が向上する効果が得られ、検出手段２のギャップ長の影響もなく、誤検出が防止されて高精度の位置検出が可能となる。   Therefore, according to this magnetic encoder 1, the effect of improving the pulse pitch accuracy of the magnetic flux waveform of the uniform pole 11 near the reference point 13 is obtained, and there is no influence of the gap length of the detecting means 2, and erroneous detection is prevented. Highly accurate position detection becomes possible.

また、従来のように磁気ロータ１０に溝加工等を施す必要もなく、着磁パターンの形成の際に回転式の着磁装置を利用して行うこともでき、着磁パターンの形成作業が煩雑化する問題も解消される。   Further, it is not necessary to perform groove processing or the like on the magnetic rotor 10 as in the prior art, and it can be performed using a rotary magnetizing device when forming the magnetized pattern, and the work of forming the magnetized pattern is complicated. The problem of becoming is also solved.

なお、各緩衝極１４、１４が、境界部ａから等配極１１と同じピッチ分だけ離間した位置に設けられる場合は、各緩衝極１４、１４の間の磁極を幅広極と見ることもできる。すなわち、この場合、幅広極の両端部に、等配極のピッチよりも幅狭で、該幅広極の極性と逆極性の緩衝極をそれぞれ設けた態様であると見ることもできる。   In addition, when each buffer pole 14 and 14 is provided in the position spaced apart from the boundary part a by the same pitch as the uniform pole 11, the magnetic pole between each buffer pole 14 and 14 can also be regarded as a wide pole. . That is, in this case, it can also be considered that the both ends of the wide pole are provided with buffer poles that are narrower than the pitch of the uniform poles and have opposite polarities to the polarities of the wide poles.

（第２の実施形態）
図３は、本発明に係る磁気エンコーダの第２の実施形態を示す要部斜視図である。図１と同一符号の部位は同一構成の部位であるため詳細な説明は省略する。 (Second Embodiment)
FIG. 3 is a main part perspective view showing a second embodiment of the magnetic encoder according to the present invention. Since the site | part of the same code | symbol as FIG. 1 is a site | part of the same structure, detailed description is abbreviate | omitted.

本実施形態では、磁気ロータ１０に、隣接する２つの幅広極１２Ａ、１２Ｂが設けられ、これらによって基準点１３が形成されている。   In this embodiment, the magnetic rotor 10 is provided with two adjacent wide poles 12A and 12B, and the reference point 13 is formed by these.

ここでは、磁気ロータ１０の外形がφ９０ｍｍ、等配極１１のＮ極とＳ極の各磁極角度が３°、幅広極１２ＡはＮ極とされ、その磁極角度が９°とされ、幅広極１２ＢはＳ極とされ、その磁極角度が９°とされている。   Here, the outer shape of the magnetic rotor 10 is φ90 mm, the magnetic pole angles of the N pole and S pole of the uniform pole 11 are 3 °, the wide pole 12A is N pole, the magnetic pole angle is 9 °, and the wide pole 12B. Is an S pole, and its magnetic pole angle is 9 °.

これら幅広極１２Ａ、１２Ｂは隣接して配置されているため、各々は一方端にのみ等配極１１が隣接することになる。従って、幅広極１２Ａには、一方に隣接する等配極１１側の端部近傍にＳ極の緩衝極１４Ａが設けられ、幅広極１２Ｂには、一方に隣接する等配極１１側の端部近傍にＮ極の緩衝極１４Ｂが設けられている。   Since these wide poles 12A and 12B are arranged adjacent to each other, the equal distribution poles 11 are adjacent to each other only at one end. Accordingly, the wide pole 12A is provided with an S-pole buffering pole 14A in the vicinity of the end on the side of the uniform pole 11 adjacent to one side, and the wide pole 12B is provided with an end on the side of the uniform pole 11 adjacent to one side. An N-pole buffer electrode 14B is provided in the vicinity.

各緩衝極１４Ａ、１４Ｂの幅広極１２Ａ、１２Ｂの端部からの位置も、幅広極１２に隣接する等配極１１側の端部から該等配極１１のピッチ分だけ離間した位置とされることが好ましく、ここでは、緩衝極１４Ａは幅広極１２Ａの端部から等配極１１のピッチ分だけ離間した３°の角度をおいた位置に設けられ、同様に緩衝極１４Ｂは幅広極１２Ｂの端部から等配極１１のピッチ分だけ離間した３°の角度をおいた位置に設けられている。また、各緩衝極１４Ａ、１４Ｂの磁極角度は０．５°とされている。   The positions of the buffer poles 14A and 14B from the ends of the wide poles 12A and 12B are also spaced from the end on the side of the uniform pole 11 adjacent to the wide pole 12 by the pitch of the uniform pole 11. Here, the buffer pole 14A is provided at a position at an angle of 3 ° spaced from the end of the wide pole 12A by the pitch of the uniform pole 11, and similarly, the buffer pole 14B is the same as the wide pole 12B. It is provided at a position with an angle of 3 ° separated from the end portion by the pitch of the uniform electrode 11. The magnetic pole angle of each buffer pole 14A, 14B is 0.5 °.

本実施形態のように基準点１３が隣接する２つの幅広極１２Ａ、１２Ｂによって形成され、各幅広極１２Ａ、１２Ｂの一方端にのみ等配極１１が隣接することにより、緩衝極１４Ａ、１４Ｂが幅広極１２Ａ、１２Ｂにそれぞれ１つだけ設けられる場合、基準点１３を確実に検出できるようにするため、各幅広極１２Ａ、１２Ｂの幅は、等配極１１のピッチの２倍以上とすることが好ましい。   As in this embodiment, the reference point 13 is formed by two adjacent wide poles 12A and 12B, and the uniform pole 11 is adjacent to only one end of each of the wide poles 12A and 12B, so that the buffer poles 14A and 14B are formed. If only one wide pole 12A, 12B is provided, the width of each wide pole 12A, 12B should be at least twice the pitch of the uniform pole 11 so that the reference point 13 can be detected reliably. Is preferred.

本実施形態に示す磁気エンコーダ１においても同様に、基準点１３近傍の等配極１１の磁束波形のパルスピッチ精度が向上する効果が得られ、検出手段２のギャップ長の影響もなく、誤検出が防止されて高精度の位置検出が可能となる。   Similarly, in the magnetic encoder 1 shown in the present embodiment, the effect of improving the pulse pitch accuracy of the magnetic flux waveform of the uniform pole 11 near the reference point 13 can be obtained, and there is no influence of the gap length of the detecting means 2 and erroneous detection. Is prevented and highly accurate position detection becomes possible.

なお、基準点１３を複数の幅広極１２によって形成する場合、その数は２つに限定されず、３つ以上とすることもできる。また、基準点１３として幅広極１２と幅の狭い磁極とを複数適宜組合せた磁極パターンとした場合にも本発明は適用可能である。   In the case where the reference point 13 is formed by a plurality of wide poles 12, the number is not limited to two, and may be three or more. The present invention is also applicable when the reference point 13 is a magnetic pole pattern in which a plurality of wide poles 12 and narrow magnetic poles are appropriately combined.

また、各緩衝極１４、１４が、境界部ａから等配極１１と同じピッチ分だけ離間した位置に設けられる場合は、緩衝極１４を挟んで境界部ａと反対側の磁極を幅広極と見ることもできる。すなわち、この場合、幅広極の一方端部に、等配極のピッチよりも幅狭で、該幅広極の極性と逆極性の緩衝極を設けた態様であると見ることもできる。   When each buffer pole 14 and 14 is provided at a position separated from the boundary a by the same pitch as the uniform pole 11, the magnetic pole on the side opposite to the boundary a across the buffer pole 14 is a wide pole. You can also see it. In other words, in this case, it can be considered that the buffer pole having a width narrower than the pitch of the uniform pole and having a polarity opposite to that of the wide pole is provided at one end of the wide pole.

本発明の磁気エンコーダは、自動車エンジンのクランク角検出に好適に使用できるが、その他一般産業、例えばロボットの腕の回転制御等、回転部材の位置検出に適用可能である。   The magnetic encoder of the present invention can be suitably used for detecting the crank angle of an automobile engine, but is applicable to other general industries, for example, the position detection of a rotating member such as the rotation control of a robot arm.

本発明に係る磁気エンコーダの第１の実施形態を示す要部斜視図The principal part perspective view which shows 1st Embodiment of the magnetic encoder which concerns on this invention. 図１に示す磁気エンコーダの基準点の近傍の磁束密度を検出センサのギャップ長を変えて測定した結果を示すグラフThe graph which shows the result of having measured the magnetic flux density near the reference point of the magnetic encoder shown in FIG. 1 by changing the gap length of the detection sensor 本発明に係る磁気エンコーダの第２の実施形態を示す要部斜視図The principal part perspective view which shows 2nd Embodiment of the magnetic encoder which concerns on this invention. 従来の磁気エンコーダを示す要部斜視図Main part perspective view showing a conventional magnetic encoder 従来の磁気エンコーダの他の例を示す要部斜視図Main part perspective view which shows the other example of the conventional magnetic encoder. 図４に示す磁気エンコーダの基準点の近傍の磁束密度を検出センサのギャップ長を変えて測定した結果を示すグラフThe graph which shows the result of having measured the magnetic flux density near the reference point of the magnetic encoder shown in FIG. 4 by changing the gap length of the detection sensor

符号の説明Explanation of symbols

１：磁気エンコーダ
１０：磁気ロータ
１１：等配極
１２、１２Ａ、１２Ｂ：幅広極
１３：基準点
１４、１４Ａ、１４Ｂ：緩衝極
２０：検出手段 1: Magnetic encoder 10: Magnetic rotor 11: Uniform pole 12, 12A, 12B: Wide pole 13: Reference point 14, 14A, 14B: Buffer pole 20: Detection means

Claims (5)

磁界の強さを検出する検出手段に対して回転する環状の磁気ロータの表面に、Ｎ極とＳ極を等配ピッチで交互に設けた等配極と、前記等配極に隣接して該等配極のピッチよりも幅広な１つ以上の幅広極とを有する着磁パターンが設けられた磁気エンコーダにおいて、
前記幅広極に隣接する前記等配極との境界部から該幅広極側に所定角度離間した位置で該幅広極内に、該幅広極の極性と逆極性の緩衝極を前記等配極のピッチよりも幅狭状に設けたことを特徴とする磁気エンコーダ。 Uniform poles in which N poles and S poles are alternately provided at an equal pitch on the surface of an annular magnetic rotor that rotates relative to a detection means that detects the strength of the magnetic field, and adjacent to the uniform poles, In a magnetic encoder provided with a magnetized pattern having one or more wide poles wider than a uniform pole pitch,
A buffer pole having a polarity opposite to the polarity of the wide pole is placed in the wide pole at a position spaced from the boundary with the uniform pole adjacent to the wide pole by a predetermined angle toward the wide pole. A magnetic encoder having a narrower width than that of the magnetic encoder. 前記緩衝極は、前記幅広極に隣接する前記等配極との境界部から該等配極のピッチ分だけ離間した位置に設けられていることを特徴とする請求項１記載の磁気エンコーダ。   The magnetic encoder according to claim 1, wherein the buffer pole is provided at a position separated from a boundary portion with the uniform pole adjacent to the wide pole by a pitch of the uniform pole. 前記緩衝極の幅は、前記等配極のピッチの１／２０〜１／３であることを特徴とする請求項１又は２記載の磁気エンコーダ。   3. The magnetic encoder according to claim 1, wherein a width of the buffer pole is 1/20 to 1/3 of a pitch of the uniform pole. 前記幅広極の一方端にのみ前記等配極が隣接し、前記緩衝極が前記幅広極に１つだけ設けられており、
前記幅広極の幅は、前記等配極のピッチの２倍以上であることを特徴とする請求項１、２又は３記載の磁気エンコーダ。 The uniform pole is adjacent to only one end of the wide pole, and only one buffer pole is provided on the wide pole,
4. The magnetic encoder according to claim 1, wherein the width of the wide pole is at least twice the pitch of the uniform poles. 前記幅広極の両端にそれぞれ前記等配極が隣接し、前記緩衝極が前記幅広極に２つ設けられており、
前記幅広極の幅は、前記等配極のピッチの３倍以上であることを特徴とする請求項１、２又は３記載の磁気エンコーダ。 The equal poles are adjacent to both ends of the wide pole, and two buffer poles are provided on the wide pole,
4. The magnetic encoder according to claim 1, wherein the width of the wide pole is at least three times the pitch of the uniform poles.
JP2007188729A 2007-07-19 2007-07-19 Magnetic encoder Pending JP2009025163A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2007188729A JP2009025163A (en) 2007-07-19 2007-07-19 Magnetic encoder

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2007188729A JP2009025163A (en) 2007-07-19 2007-07-19 Magnetic encoder

Publications (1)

Publication Number Publication Date
JP2009025163A true JP2009025163A (en) 2009-02-05

Family

ID=40397104

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2007188729A Pending JP2009025163A (en) 2007-07-19 2007-07-19 Magnetic encoder

Country Status (1)

Country Link
JP (1) JP2009025163A (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012018086A (en) * 2010-07-08 2012-01-26 Aisan Ind Co Ltd Rotational position sensor
JP2013015825A (en) * 2011-06-06 2013-01-24 Canon Inc Driving device, pan head device with the same, and lens device
WO2014167857A1 (en) * 2013-04-10 2014-10-16 株式会社デンソー Encoder
WO2015015725A1 (en) * 2013-07-30 2015-02-05 株式会社デンソー Rotating body and rotation detection system including same
JP2015028450A (en) * 2013-07-30 2015-02-12 株式会社デンソー Rotor
JP2015095642A (en) * 2013-11-08 2015-05-18 株式会社エムジー Magnet reducing magnetic flux density change with cavity fluctuation, and magnetization method thereof
JP2016031320A (en) * 2014-07-30 2016-03-07 株式会社デンソー Magnetic encoder device
WO2016157812A1 (en) * 2015-04-01 2016-10-06 株式会社デンソー Magnetic ring and rotation sensor comprising same
JP2018133453A (en) * 2017-02-15 2018-08-23 内山工業株式会社 Magnetization method, magnetization device and magnet for magnetic encoder

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012018086A (en) * 2010-07-08 2012-01-26 Aisan Ind Co Ltd Rotational position sensor
JP2013015825A (en) * 2011-06-06 2013-01-24 Canon Inc Driving device, pan head device with the same, and lens device
WO2014167857A1 (en) * 2013-04-10 2014-10-16 株式会社デンソー Encoder
JP2014206387A (en) * 2013-04-10 2014-10-30 株式会社デンソー Encoder
WO2015015725A1 (en) * 2013-07-30 2015-02-05 株式会社デンソー Rotating body and rotation detection system including same
JP2015028450A (en) * 2013-07-30 2015-02-12 株式会社デンソー Rotor
JP2015028449A (en) * 2013-07-30 2015-02-12 株式会社デンソー Rotor and rotation detection system including the same
JP2015095642A (en) * 2013-11-08 2015-05-18 株式会社エムジー Magnet reducing magnetic flux density change with cavity fluctuation, and magnetization method thereof
JP2016031320A (en) * 2014-07-30 2016-03-07 株式会社デンソー Magnetic encoder device
WO2016157812A1 (en) * 2015-04-01 2016-10-06 株式会社デンソー Magnetic ring and rotation sensor comprising same
JP2016194487A (en) * 2015-04-01 2016-11-17 株式会社デンソー Magnetic ring and rotation sensor including the same
JP2018133453A (en) * 2017-02-15 2018-08-23 内山工業株式会社 Magnetization method, magnetization device and magnet for magnetic encoder

Similar Documents

Publication Publication Date Title
JP2009025163A (en) Magnetic encoder
JP4698610B2 (en) Method for magnetizing ring magnet and magnetic encoder
JP6345235B2 (en) Magnetic position detection device and magnetic position detection method
TWI392856B (en) Origin position signal detector
JP2007024738A (en) Rotational angle detector
JP2007017353A (en) Magnetic encoder
US10969252B2 (en) System for determining at least one rotation parameter of a rotating member
JP4941707B2 (en) Angle detector
JPWO2011001984A1 (en) Rotation angle detector
JPWO2008050581A1 (en) Rotation angle detector
JP2010145371A (en) Angle detection apparatus
JP6530797B2 (en) Rotation angle detection device
KR20190112752A (en) Magnetic encoder and its manufacturing method
WO2016157812A1 (en) Magnetic ring and rotation sensor comprising same
JP2005062189A (en) Magnetic multipole encoder
JP5394289B2 (en) Magnetic detector and magnetic encoder
JP2007093532A (en) Magnetic sensor device
JP5158867B2 (en) Rotation angle detector
TW201510486A (en) Magnetic encoder and sensor device
JP6201910B2 (en) Rotation detection sensor and manufacturing method thereof
JP5193930B2 (en) Small angle detection sensor
WO2014162742A1 (en) Magnet for rotation angle sensor and rotation angle sensor
JP6213536B2 (en) Magnetic field detection device and rotation detection device
JP6459727B2 (en) Magnetic ring and rotation sensor having the magnetic ring
JP2006162557A (en) Torque sensor

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20100622

A072 Dismissal of procedure

Effective date: 20111027

Free format text: JAPANESE INTERMEDIATE CODE: A073