JP2010025784A

JP2010025784A - Speed measuring apparatus

Info

Publication number: JP2010025784A
Application number: JP2008188131A
Authority: JP
Inventors: Kyohei Minoda; 強平蓑田; Akihiko Maruyama; 昭彦丸山; Taigen Kin; 太▲げん▼ 金; Yasuhiro Koga; 康裕古閑; Yuichi Yamaji; 祐一山地
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2008-07-22
Filing date: 2008-07-22
Publication date: 2010-02-04

Abstract

<P>PROBLEM TO BE SOLVED: To provide a speed measuring apparatus having a simple and inexpensive constitution and having very few effects on measuring accuracy even if an on object to be measured is driven in a traveling direction by an electromagnetic force. <P>SOLUTION: A magnetic flux linear region in which a change in a unit distance traveled by magnetic flux flowing through a magnetic path can be regarded as having a constant change rate value of magnetic flux/distance is secured in the vicinity of the beginning position and the vicinity of the end position of the object to be measured 1. The traveling speed of the object to be measured 1 is determined on the basis of a voltage detection value of the coil 5 and the change rate value of magnetic flux/distance while the object to be measured 1 is traveling through the magnetic flux linear regions. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

この発明は、所定の移動方向に移動する被測定物の上記移動方向の移動速度を測定する速度測定装置に係り、特に、簡便な構成により測定を可能とする技術に関する。 The present invention relates to a speed measuring apparatus that measures the moving speed of an object to be measured that moves in a predetermined moving direction, and more particularly to a technique that enables measurement with a simple configuration.

従来の速度測定装置においては，永久磁石，コイルを備え被測定物には強磁性体の挿入物を入れる構成で磁場変化の割合、または被測定物の速度に比例した電圧を発生させることで出力が直接測定速度になる様な仕組みになっている（例えば、特許文献1参照）。 In the conventional speed measurement device, a permanent magnet and a coil are provided, and a ferromagnetic material is inserted in the object to be measured, and the output is generated by generating a voltage proportional to the rate of change in the magnetic field or the speed of the object to be measured. Is a mechanism that directly reaches the measurement speed (for example, see Patent Document 1).

特表２００６−５０８３６５号公報（６頁、図２）Japanese translation of PCT publication No. 2006-508365 (page 6, FIG. 2)

従来の速度測定装置では、移動範囲の全てに亘って線形な磁場を形成するために、移動範囲全体で線形になるような強い磁場強度が必要となり装置が複雑高価になるという問題があった。また、磁場変化の検出方向が被測定物の移動方向に対して平行方向であることから、例えば、被測定物が電磁力で移動方向に駆動されるものであれば、検出部が漏れ磁場の影響を受け易く測定精度が低下するという問題があった。 In the conventional speed measuring device, in order to form a linear magnetic field over the entire moving range, a strong magnetic field strength that is linear in the entire moving range is required, and the device is complicated and expensive. In addition, since the detection direction of the magnetic field change is parallel to the movement direction of the object to be measured, for example, if the object to be measured is driven in the movement direction by electromagnetic force, the detection unit has a leakage magnetic field. There was a problem that the measurement accuracy was easily deteriorated.

この発明は以上のような従来の問題点を解消するためになされたもので、簡便安価な構成で、しかも、被測定物が電磁力で移動方向に駆動されるものであっても測定精度への影響が小さい速度測定装置を得ることを目的とする。 The present invention has been made to solve the conventional problems as described above, and has a simple and inexpensive configuration, and even if the object to be measured is driven in the moving direction by electromagnetic force, the measurement accuracy is improved. An object of the present invention is to obtain a speed measuring device that is less influenced by the above.

この発明に係る速度測定装置は、所定の移動方向に移動する被測定物の移動方向の移動速度を測定するものであって、
被測定物に取り付けられた第１の磁性材、コ字状でその両脚が第１の磁性材と対向し移動方向に所定距離離反するよう配置された第２の磁性材、第１と第２の磁性材とで形成される磁路に起磁力を付加する起磁力材、および被測定物の移動に伴う磁路を流れる磁束の単位時間当たりの変化ｄφ／ｄｔに基づく電圧を検出するコイルを備え、
被測定物の移動に伴う磁路を流れる磁束の単位移動距離当たりの変化ｄφ／ｄｘが所定の移動距離に亘って一定の磁束／距離変化率値とみなせる磁束線形領域を被測定物の移動範囲内の一部に確保できるよう第１の磁性材と第２の磁性材との相対位置関係を設定しておき、
被測定物が磁束線形領域を移動中のコイルの電圧検出値と磁束／距離変化率値とから被測定物の移動速度を求めるものである。 The speed measuring device according to the present invention measures a moving speed in a moving direction of an object to be measured that moves in a predetermined moving direction,
A first magnetic material attached to the object to be measured, a U-shaped second magnetic material arranged so that both legs thereof face the first magnetic material and are separated from each other by a predetermined distance in the moving direction, first and second A magnetomotive force material that adds a magnetomotive force to a magnetic path formed by the magnetic material, and a coil that detects a voltage based on a change dφ / dt of a magnetic flux flowing through the magnetic path associated with the movement of the object to be measured per unit time. Prepared,
The moving range of the object to be measured is a magnetic flux linear region in which the change dφ / dx per unit moving distance of the magnetic flux flowing through the magnetic path accompanying the movement of the object to be measured can be regarded as a constant magnetic flux / distance change rate value over a predetermined moving distance. The relative positional relationship between the first magnetic material and the second magnetic material is set so that it can be secured in a part of the inside,
The moving speed of the object to be measured is obtained from the voltage detection value of the coil and the magnetic flux / distance change rate value when the object to be measured is moving in the magnetic flux linear region.

この発明に係る速度測定装置は、以上のように、被測定物がその移動範囲の一部に確保した磁束線形領域を移動中のコイルの電圧検出値と磁束／距離変化率値とから被測定物の移動速度を求めることができるので、移動範囲の全てに亘って線形な磁場を形成する必要が無く、装置が簡便安価となる。また、コイルによる磁束変化の検出方向が被測定物の移動方向と垂直な方向となるので、被測定物が電磁力で移動方向に駆動されるものであっても測定精度への影響が小さくなる。 As described above, the speed measuring device according to the present invention measures the voltage to be measured from the voltage detection value and the flux / distance change rate value of the moving coil in the magnetic flux linear region secured in a part of the moving range of the measured object. Since the moving speed of the object can be obtained, it is not necessary to form a linear magnetic field over the entire moving range, and the apparatus is simple and inexpensive. Further, since the direction of detection of the magnetic flux change by the coil is perpendicular to the moving direction of the object to be measured, even if the object to be measured is driven in the moving direction by electromagnetic force, the influence on the measurement accuracy is reduced. .

実施の形態１．
図１は、この発明の実施の形態１における速度測定装置の原理を説明するための基本構成を示す図である。図１（ａ）は、図では左右方向となる移動方向に移動する被測定物１がその始端位置にあるときの状態、図１（ｂ）は、図１（ａ）の始端位置から被測定物１が図の左方に移動し終端位置に至ったときの状態を示す。被測定物１には強磁性体からなる第１の磁性材２が取り付けられている。そして、移動する被測定物１に対し装置に固定されたコ字状の強磁性体からなる第２の磁性材３が設けられている。第２の磁性材３の一方の脚３Ａには起磁力材としての永久磁石４が取り付けられ、他方の脚３Ｂには鎖交する磁束の時間変化（磁束の単位時間当たりの変化）に基づく電圧を検出するコイル５が巻回されている。 Embodiment 1 FIG.
FIG. 1 is a diagram showing a basic configuration for explaining the principle of a velocity measuring apparatus according to Embodiment 1 of the present invention. FIG. 1A shows a state in which the object to be measured 1 moving in the moving direction, which is the left-right direction in the figure, is at its starting end position, and FIG. 1B shows the object to be measured from the starting end position in FIG. The state when the object 1 moves to the left in the figure and reaches the end position is shown. A first magnetic material 2 made of a ferromagnetic material is attached to the DUT 1. A second magnetic material 3 made of a U-shaped ferromagnetic material fixed to the apparatus is provided for the object to be measured 1 that moves. A permanent magnet 4 as a magnetomotive force material is attached to one leg 3A of the second magnetic material 3, and a voltage based on a change in magnetic flux linked with time (change in magnetic flux per unit time) is applied to the other leg 3B. The coil 5 for detecting is wound.

以上の構成により、第１の磁性材２と第２の磁性材３とによりエアギャップを介して磁路が形成される。そして、この磁路内に永久磁石４が挿入されているので、その永久磁石４の起磁力により当該磁路に磁束が流れる。ここで、被測定物１が移動すると、その位置に応じて第１の磁性材２と第２の磁性材３との相対位置関係が変化し、それに伴って当該磁路の磁気抵抗が変化し磁路に流れる磁束も変化する。コイル５は、その磁束の変化を検出するものである。 With the above configuration, a magnetic path is formed by the first magnetic material 2 and the second magnetic material 3 through an air gap. And since the permanent magnet 4 is inserted in this magnetic path, magnetic flux flows into the said magnetic path by the magnetomotive force of the permanent magnet 4. FIG. Here, when the DUT 1 moves, the relative positional relationship between the first magnetic material 2 and the second magnetic material 3 changes according to the position, and the magnetic resistance of the magnetic path changes accordingly. The magnetic flux flowing through the magnetic path also changes. The coil 5 detects the change of the magnetic flux.

図２は、総移動量１７ｍｍの電磁アクチュエータを例にとった場合の、被測定物１の移動位置とコイル５が巻回された脚３Ｂの磁束密度との関係を示したものである。（１）は、被測定物１が図１（ａ）で示す始端位置にある場合で、ここでは、第１の磁性材２と脚３Ａとの移動方向中心位置が一致しており、図２の付図に示すようにエアギャップ長が大きく磁束量は小さな値となっている。被測定物１が移動していくと次第にエアギャップ長が減少しそれに応じて磁束量が増大し、移動範囲のほぼ中央の（２）で、第１の磁性材２が脚３Ａと脚３Ｂとのほぼ中間位置となりエアギャップ長が最小となって磁束量が最大となる。
被測定物１の移動が更に進むと再びエアギャップ長が増大し、図１（ｂ）で示す、第１の磁性材２と脚３Ｂとの移動方向中心位置が一致する終端位置に至ると、同じく図２の付図に示すように、エアギャップ長が最長となって磁束量が最小となる。 FIG. 2 shows the relationship between the movement position of the DUT 1 and the magnetic flux density of the leg 3B around which the coil 5 is wound when an electromagnetic actuator having a total movement amount of 17 mm is taken as an example. (1) is the case where the DUT 1 is at the start position shown in FIG. 1A, and here, the movement direction center positions of the first magnetic material 2 and the leg 3A are the same, and FIG. As shown in the attached drawing, the air gap length is large and the amount of magnetic flux is small. As the DUT 1 moves, the air gap length gradually decreases, and the amount of magnetic flux increases accordingly. At the center (2) of the moving range, the first magnetic material 2 becomes the legs 3A and 3B. The air gap length is minimized and the amount of magnetic flux is maximized.
When the movement of the DUT 1 further proceeds, the air gap length increases again, and when the end position is reached, the center positions of the first magnetic material 2 and the leg 3B in the movement direction coincide as shown in FIG. Similarly, as shown in the attached drawing of FIG. 2, the air gap length becomes the longest and the magnetic flux amount becomes the minimum.

即ち、被測定物１の移動に伴いコイル５と鎖交する磁束量の変化特性は、被測定物１の移動範囲のほぼ中央で極大値となる常に下に凸の曲線となる。そして、被測定物１の移動範囲に対して第２の磁性材３を適当に配置することにより、図３に示すように、被測定物１の始端位置近傍および終端位置近傍に、被測定物１の移動に伴う磁束量の単位移動距離当たりの変化が一定の値とみなせる磁束線形領域を確保することが出来る。この磁束線形領域は、図の磁束量−距離の特性曲線が直線とみなせる領域と言い換えることが出来る。
以上のように、磁束量が移動範囲のほぼ中央で極大値をとる二次関数状に変化すると、その移動範囲の裾野に該当する始端近傍および終端近傍に磁束線形領域を確保し易くなるわけである。 That is, the change characteristic of the amount of magnetic flux interlinking with the coil 5 with the movement of the device under test 1 is always a downwardly convex curve having a maximum value at the approximate center of the moving range of the device under test 1. Then, by appropriately arranging the second magnetic material 3 with respect to the moving range of the device under test 1, as shown in FIG. 3, the device under test near the start position and the end position of the device under test 1. It is possible to secure a magnetic flux linear region in which the change per unit moving distance of the magnetic flux amount associated with the movement of 1 can be regarded as a constant value. This magnetic flux linear region can be rephrased as a region in which the magnetic flux amount-distance characteristic curve in the figure can be regarded as a straight line.
As described above, when the amount of magnetic flux changes to a quadratic function having a maximum value at the approximate center of the moving range, it is easy to secure a magnetic flux linear region in the vicinity of the start end and the end corresponding to the bottom of the moving range. is there.

磁束量φに相当する磁束密度をｙ（Ｔ）、移動距離をｘ（ｍｍ）とし、ここでの具体例に当てはめると、始端近傍には、直線ｙ＝−０．０８２ｘ＋αとみなせる磁束線形領域が存在する。また、終端近傍には、直線ｙ＝０．０１７ｘ−βとみなせる磁束線形領域が存在する。
従って、この磁束線形領域においては、磁束量の単位移動距離当たりの変化は図３に示す特性の勾配（磁束／距離変化率値）に相当し、それぞれｄｙ／ｄｘ＝−０．０８２、ｄｙ／ｄｘ＝０．０１７となる。 Assuming that the magnetic flux density corresponding to the magnetic flux amount φ is y (T) and the moving distance is x (mm), and applying this example, a magnetic flux linear region that can be regarded as a straight line y = −0.082x + α exists in the vicinity of the starting end. Exists. Further, in the vicinity of the terminal end, there is a magnetic flux linear region that can be regarded as a straight line y = 0.177x−β.
Therefore, in this magnetic flux linear region, the change in the amount of magnetic flux per unit movement distance corresponds to the characteristic gradient (magnetic flux / distance change rate value) shown in FIG. 3, and dy / dx = −0.082, dy / dx = 0.177.

そして、被測定物１がこの磁束線形領域を移動中にコイル５に発生する電圧ｖは、磁束量の単位時間当たりの変化に相当する。即ち、
ｖ＝ｄｙ／ｄｔ
で表される。
従って、被測定物１の単位時間当たりの移動距離である移動速度ｄｘ／ｄｔは、
ｄｘ／ｄｔ＝（ｄｙ／ｄｔ）／（ｄｙ／ｄｘ）＝（電圧ｖ）／（磁束／距離変化率値）
の式により求めることが出来る。 The voltage v generated in the coil 5 while the DUT 1 moves in this magnetic flux linear region corresponds to a change in the amount of magnetic flux per unit time. That is,
v = dy / dt
It is represented by
Accordingly, the moving speed dx / dt which is the moving distance per unit time of the DUT 1 is
dx / dt = (dy / dt) / (dy / dx) = (voltage v) / (magnetic flux / distance change rate value)
It can be calculated by the following formula.

図４は、被測定物１の移動速度を測定する要領を説明する図である。図に示すように、例えば、被測定物１に取り付けられた発光ダイオード６とこの発光ダイオード６と対応して磁束線形領域に相当する位置に取り付けられた受光ダイオード７Ａ、７Ｂとからなる位置検出手段を設ける。これら受光ダイオード７Ａ、７Ｂは、この図３の例では、それぞれ始端近傍の磁束線形領域内である全移動範囲の２０％に相当する位置、および終端近傍の磁束線形領域内である全移動範囲の９０％に相当する位置に設置する。 FIG. 4 is a diagram for explaining a procedure for measuring the moving speed of the DUT 1. As shown in the figure, for example, a position detecting means comprising a light emitting diode 6 attached to the DUT 1 and light receiving diodes 7A and 7B attached to the light emitting diode 6 at positions corresponding to magnetic flux linear regions. Is provided. In the example of FIG. 3, the light receiving diodes 7A and 7B are located at positions corresponding to 20% of the total moving range in the magnetic flux linear region near the start end and in the total moving range in the magnetic flux linear region near the terminal end. Install at a position corresponding to 90%.

そして、電圧出力回路８は、コイル５からの電圧を入力し、被測定物１が磁束線形領域を通過中であることを受光ダイオード７Ａ、または７Ｂからのトリガ信号の入力で検知し、そのタイミングでコイル５の電圧を出力する。速度演算回路９は、電圧出力回路８からの電圧信号と予め保存しているそれぞれの磁束線形領域に応じた磁束／距離変化率値のデータとから被測定物１の移動速度を演算する。 The voltage output circuit 8 receives the voltage from the coil 5, detects that the device under test 1 is passing through the magnetic flux linear region, and receives the trigger signal from the light receiving diode 7A or 7B. To output the voltage of the coil 5. The speed calculation circuit 9 calculates the moving speed of the DUT 1 from the voltage signal from the voltage output circuit 8 and the magnetic flux / distance change rate data corresponding to each magnetic flux linear region stored in advance.

なお、厳密には、被測定物１の移動速度は、その位置によって変化するが、例えば、図３で示したように、磁束線形領域を２箇所確保できれば、両者での測定結果の平均値を求めることで位置による変化分を抑制することも出来る。
また、電磁アクチュエータの異常や経年変化をこの速度測定結果から判定するような場合には、同一の磁束線形領域での速度測定結果の履歴を照合すれば足りるので、上述の位置による変化分は問題にならない。 Strictly speaking, the moving speed of the DUT 1 varies depending on its position. For example, as shown in FIG. 3, if two magnetic flux linear regions can be secured, the average value of the measurement results of both is obtained. By calculating, it is possible to suppress the change due to the position.
In addition, when judging abnormalities and secular changes of electromagnetic actuators from this speed measurement result, it is sufficient to collate the history of speed measurement results in the same magnetic flux linear region. do not become.

図５は、被測定物１をその移動方向に駆動する電磁アクチュエータ１０の構成を示す図である。電磁アクチュエータ１０は、固定鉄心１１とこの固定鉄心１１の内部に駆動方向に移動可能に支持された可動鉄心１２と固定鉄心１１および可動鉄心１２からなる磁気回路に起磁力を与える電磁コイル１３とから構成される。そして、被測定物１は可動鉄心１２に取り付けられている。この場合、可動鉄心１２を駆動する磁束Φは、駆動方向（被測定物１の移動方向）の成分を有するもので、その漏れ分が本願発明の速度測定装置に及ぼす影響が懸念される。
しかし、図５に示すように、コイル５が検出する磁束φは、当該移動方向と垂直な成分であり、電磁アクチュエータ１０で発生する磁束Φの影響をほとんど受けないことが判る。 FIG. 5 is a diagram showing the configuration of the electromagnetic actuator 10 that drives the DUT 1 in its moving direction. The electromagnetic actuator 10 includes a fixed iron core 11, a movable iron core 12 supported inside the fixed iron core 11 so as to be movable in the driving direction, and an electromagnetic coil 13 that applies a magnetomotive force to a magnetic circuit including the fixed iron core 11 and the movable iron core 12. Composed. The DUT 1 is attached to the movable iron core 12. In this case, the magnetic flux Φ for driving the movable iron core 12 has a component in the driving direction (the moving direction of the DUT 1), and there is a concern about the influence of the leakage on the speed measuring device of the present invention.
However, as shown in FIG. 5, it can be seen that the magnetic flux φ detected by the coil 5 is a component perpendicular to the moving direction and is hardly affected by the magnetic flux Φ generated by the electromagnetic actuator 10.

以上のように、この発明の実施の形態１に係る速度測定装置は、磁束の単位移動距離当たりの変化が所定の移動距離に亘って一定とみなせる磁束線形領域を移動範囲の一部に確保できればコイル５の電圧検出値から被測定物１の移動速度を測定できるので、従来のように、移動範囲の全てに亘って線形な磁場を形成するための強力な磁場を必要とせず、装置が簡便安価となる。
また、この発明の実施の形態１に係る速度測定装置においては、コイル５による磁束変化の検出方向が被測定物１の移動方向と垂直な方向となるので、被測定物１が電磁力で移動方向に駆動される、従って、駆動力を得るため移動方向と同一方向の磁束が発生しその漏れ成分が存在しても、本願発明による速度測定精度への影響は小さくなる。 As described above, the speed measurement device according to the first embodiment of the present invention can secure a magnetic flux linear region in which a change per unit moving distance of the magnetic flux can be considered constant over a predetermined moving distance in a part of the moving range. Since the moving speed of the DUT 1 can be measured from the voltage detection value of the coil 5, it is not necessary to use a strong magnetic field for forming a linear magnetic field over the entire moving range as in the prior art, and the apparatus is simple. It will be cheap.
Further, in the velocity measuring apparatus according to the first embodiment of the present invention, the direction of detection of the magnetic flux change by the coil 5 is perpendicular to the direction of movement of the device under test 1, so that the device under test 1 moves by electromagnetic force Therefore, even if a magnetic flux in the same direction as the moving direction is generated and a leakage component exists in order to obtain a driving force, the influence on the speed measurement accuracy according to the present invention is reduced.

なお、以上の説明では、移動範囲の２箇所に磁束線形領域を確保するようにしたが、１箇所のみに確保するものとしてもよいことは勿論である。この場合、装置の全体を更に簡便なものとできる可能性がある。
また、測定精度の若干の低下を許容できれば、以下のような構成でも、本願発明を適用することが出来る。即ち、例えば、オシロスコープを使用し、被測定物１が始端から終端に移動する過程のコイル５の電圧出力−時間特性を求める。そして、被測定物１が磁束線形領域を通過中であることの判断を、上記オシロスコープの出力である電圧−時間特性上の時間軸に検出時点（例えば、移動全時間に対する割合％で規定する）を設定することで行い、この検出時点におけるコイル５の出力から移動速度を演算する。 In the above description, the magnetic flux linear regions are secured at two places in the movement range, but it is needless to say that the magnetic flux linear areas may be secured only at one place. In this case, there is a possibility that the entire apparatus can be further simplified.
In addition, the present invention can be applied to the following configurations as long as a slight decrease in measurement accuracy can be allowed. That is, for example, using an oscilloscope, the voltage output-time characteristic of the coil 5 in the process in which the DUT 1 moves from the start to the end is obtained. Then, the determination that the DUT 1 is passing through the magnetic flux linear region is detected on the time axis on the voltage-time characteristic that is the output of the oscilloscope (for example, specified as a percentage of the total movement time). Is set, and the moving speed is calculated from the output of the coil 5 at the time of detection.

この発明の実施の形態１における速度測定装置の基本構成を示す図である。It is a figure which shows the basic composition of the speed measuring device in Embodiment 1 of this invention. 被測定物１の移動位置とコイル５が巻回された脚３Ｂの磁束密度との関係を示す図である。It is a figure which shows the relationship between the movement position of the to-be-measured object 1, and the magnetic flux density of the leg 3B by which the coil 5 was wound. 磁束線形領域を説明するための図である。It is a figure for demonstrating a magnetic flux linear area | region. 被測定物１の移動速度を測定する要領を説明する図である。It is a figure explaining the point which measures the moving speed of DUT 1. 被測定物１をその移動方向に駆動する電磁アクチュエータ１０の構成を示す図である。It is a figure which shows the structure of the electromagnetic actuator 10 which drives the to-be-measured object 1 in the moving direction.

符号の説明Explanation of symbols

１被測定物、２第１の磁性材、３第２の磁性材、３Ａ，３Ｂ脚、
４永久磁石、５コイル、６発光ダイオード、７Ａ，７Ｂ受光ダイオード、
８電圧出力回路、９速度演算回路。 1 object to be measured, 2 first magnetic material, 3nd magnetic material, 3A, 3B legs,
4 permanent magnet, 5 coil, 6 light emitting diode, 7A, 7B light receiving diode,
8 Voltage output circuit, 9 Speed calculation circuit.

Claims

所定の移動方向に移動する被測定物の上記移動方向の移動速度を測定するものであって、
上記被測定物に取り付けられた第１の磁性材、コ字状でその両脚が上記第１の磁性材と対向し上記移動方向に所定距離離反するよう配置された第２の磁性材、上記第１と第２の磁性材とで形成される磁路に起磁力を付加する起磁力材、および上記被測定物の移動に伴う上記磁路を流れる磁束の単位時間当たりの変化ｄφ／ｄｔに基づく電圧を検出するコイルを備え、
上記被測定物の移動に伴う上記磁路を流れる磁束の単位移動距離当たりの変化ｄφ／ｄｘが所定の移動距離に亘って一定の磁束／距離変化率値とみなせる磁束線形領域を上記被測定物の移動範囲内の一部に確保できるよう上記第１の磁性材と第２の磁性材との相対位置関係を設定しておき、
上記被測定物が上記磁束線形領域を移動中の上記コイルの電圧検出値と上記磁束／距離変化率値とから上記被測定物の移動速度を求めることを特徴とする速度測定装置。 Measuring the moving speed of the object to be measured moving in a predetermined moving direction in the moving direction,
A first magnetic material attached to the object to be measured; a U-shaped second magnetic material arranged so that both legs thereof face the first magnetic material and are separated by a predetermined distance in the moving direction; Based on a magnetomotive force material that adds a magnetomotive force to a magnetic path formed by the first and second magnetic materials, and a change dφ / dt per unit time of the magnetic flux that flows through the magnetic path as the object to be measured moves. With a coil to detect the voltage,
A magnetic flux linear region in which the change dφ / dx per unit moving distance of the magnetic flux flowing through the magnetic path accompanying the movement of the measured object can be regarded as a constant magnetic flux / distance change rate value over a predetermined moving distance. The relative positional relationship between the first magnetic material and the second magnetic material is set so that it can be secured in a part within the movement range of
A speed measuring apparatus for obtaining a moving speed of the object to be measured from a voltage detection value of the coil and the magnetic flux / distance change rate value when the object to be measured is moving in the magnetic flux linear region.

上記第２の磁性材のそれぞれ一方の脚に上記起磁力材としての永久磁石を取り付け他方の脚に上記コイルを取り付けるとともに、上記被測定物が上記移動範囲の始端位置にあるとき上記第１の磁性材の上記移動方向中心位置と上記第２の磁性材の上記一方の脚または他方の脚の上記移動方向中心位置とが一致するように、かつ上記被測定物が上記移動範囲の終端位置にあるとき上記第１の磁性材の上記移動方向中心位置と上記第２の磁性材の上記他方の脚または一方の脚の上記移動方向中心位置とが一致するように上記被測定物の移動範囲に対して上記第２の磁性材を配置することにより、上記被測定物の移動範囲のほぼ中央で上記磁路に流れる磁束が極大値となり、上記被測定物の始端近傍および終端近傍に上記磁束線形領域を確保するようにしたことを特徴とする請求項１記載の速度測定装置。 A permanent magnet as the magnetomotive force material is attached to one leg of each of the second magnetic materials, and the coil is attached to the other leg. When the object to be measured is at the start position of the moving range, the first magnetic material is attached. The measurement object is positioned at the end position of the movement range so that the movement direction center position of the magnetic material and the movement direction center position of the one leg or the other leg of the second magnetic material coincide with each other. In some cases, the moving range of the object to be measured is such that the center position in the moving direction of the first magnetic material matches the center position in the moving direction of the other leg or one leg of the second magnetic material. On the other hand, by arranging the second magnetic material, the magnetic flux flowing through the magnetic path is at the maximum value in the approximate center of the moving range of the object to be measured, and the magnetic flux linearity is near the start end and the end of the object to be measured. I will secure the area Speed measuring apparatus according to claim 1, characterized in that the.

上記被測定物が上記磁束線形領域を移動中であることを判定する位置検出手段を備え、この位置検出手段の判定出力に基づき、上記被測定物の移動速度を求めるための上記コイルの電圧検出値を得るようにしたことを特徴とする請求項１または２に記載の速度測定装置。 Position detecting means for determining that the object to be measured is moving in the magnetic flux linear region, and voltage detection of the coil for determining the moving speed of the object to be measured based on the determination output of the position detecting means. 3. The speed measuring device according to claim 1, wherein a value is obtained.

上記被測定物を上記移動方向に駆動する駆動源が、上記移動方向成分の磁束の発生を伴う電磁アクチュエータであることを特徴とする請求項１ないし３のいずれか１項に記載の速度測定装置。 4. The speed measuring device according to claim 1, wherein the driving source for driving the object to be measured in the moving direction is an electromagnetic actuator accompanied by generation of magnetic flux of the moving direction component. .