WO2007080941A1 - Commutateur magnetique - Google Patents

Commutateur magnetique Download PDF

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Publication number
WO2007080941A1
WO2007080941A1 PCT/JP2007/050280 JP2007050280W WO2007080941A1 WO 2007080941 A1 WO2007080941 A1 WO 2007080941A1 JP 2007050280 W JP2007050280 W JP 2007050280W WO 2007080941 A1 WO2007080941 A1 WO 2007080941A1
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WO
WIPO (PCT)
Prior art keywords
gmr
pair
fixed portion
magnetic switch
gmr element
Prior art date
Application number
PCT/JP2007/050280
Other languages
English (en)
Japanese (ja)
Inventor
Masahiro Kawamura
Ichiro Tokunaga
Original Assignee
Alps Electric Co., Ltd.
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 Alps Electric Co., Ltd. filed Critical Alps Electric Co., Ltd.
Publication of WO2007080941A1 publication Critical patent/WO2007080941A1/fr

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
    • G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
    • G01D5/142—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices
    • G01D5/145—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices influenced by the relative movement between the Hall device and magnetic fields

Definitions

  • the present invention relates to a contactless switch, and more particularly to a magnetic switch using a GMR element.
  • a switch that can be a contactless system for example, there is a magnetic switch using a Hall element (for example, Patent Document 1).
  • Patent Document 2 There is also a magnetic switch using a GMR element (for example, Patent Document 2).
  • the GMR element there is one composed of a fixed resistance portion in which the resistance value cannot be adjusted and a variable resistance portion in which the resistance value can be adjusted (for example, Patent Document 3).
  • Patent Document 1 JP-A-8-17311
  • Patent Document 2 Japanese Patent Laid-Open No. 2003-60256
  • Patent Document 3 JP 2001-111137 A
  • the output voltage V of the Hall element is such that the Hall coefficient is R, the Hall element thickness is d,
  • the Hall coefficient R and thickness d are determined by the selected Hall element.
  • Patent Document 3 when a method using a fixed resistor that cannot adjust the resistance value of one GMR element is adopted, it is not necessary to adjust the direction between the pair of GMR elements. .
  • the temperature characteristics of GMR elements and fixed resistors are generally different, there is a problem that if the temperature changes, the balance of the midpoint voltage is lost and the detection accuracy is reduced, causing malfunctions.
  • the present invention is for solving the above-described conventional problems, and it is an object of the present invention to provide a magnetic switch that is unlikely to malfunction with a small number of parts.
  • Another object of the present invention is to provide a magnetic switch that suppresses the influence of temperature changes.
  • the present invention provides a fixed portion, a moving mechanism that moves in parallel with the fixed portion, and an external magnetic field having different polarities and a pair provided on one of the fixed portion and the moving mechanism.
  • a magnetoresistive effect element having a GMR element force provided on the other side, a power supply unit for supplying a predetermined current to the magnetoresistive effect element, a voltage output from the magnetoresistive effect element, and a predetermined And a comparator that outputs a switching signal based on the comparison result.
  • a magnetic switch can be configured with one GMR element. Strikes can be reduced. In addition, it is not necessary to use a large magnet with a small number of parts, so it can be downsized.
  • the present invention provides a pair of a fixed portion, a moving mechanism that moves in parallel to the fixed portion, an external magnetic field having different polarities, and a pair of one provided on the fixed portion and the moving mechanism.
  • a comparator that compares a voltage output from the GMR element with a predetermined threshold value and outputs a switching signal based on the comparison result.
  • a GMR element covered with a magnetic shielding member can be used as a fixed resistor. Since one of a pair of GMR elements formed simultaneously on the same substrate can be used as a fixed resistor and the other can be used as a variable resistor whose resistance value varies with an external magnetic field, The temperature characteristics of the variable resistance can be matched. For this reason, it is possible to provide a magnetic switch that can operate stably with respect to temperature changes.
  • the GMR element can be driven with a constant current, the power consumption can be reduced. Furthermore, there is no need to use a magnet with a large external dimension or a magnet with a large maximum energy product, so that a small and inexpensive magnetic switch can be obtained.
  • the pair of GMR elements are formed on a common substrate cut out from the same wafer.
  • the magnetic switch of the present invention can provide a small and inexpensive magnetic switch.
  • FIG. 1 is a perspective view showing a magnetic switch using one GMR element as a first embodiment of the present invention
  • FIG. 2 is a plan view showing a magnetization direction of the GMR element
  • FIG. 3 is a configuration of the magnetic switch.
  • 4 and 5 are explanatory diagrams for explaining the operation of the magnetic switch.
  • FIG. 4 shows the case in the first position
  • FIG. 5 shows the case in the second position.
  • Fig. 6 is a graph showing the output characteristics of the magnetic switch.
  • Fig. 1 shows a so-called moving magnet type magnetic switch.
  • a GMR element (magnetoresistive element) 10 is fixed on a wall surface 20 on the fixed part side.
  • a moving mechanism (not shown) that slides while maintaining a state parallel to the wall surface 20 is provided in the vicinity of the wall surface (fixed portion) 20.
  • a pair of magnets Ml and M2 are fixed to the tip of the moving mechanism, and the pair of magnets Ml and M2 can freely advance and retreat in the Y1-Y2 direction shown in the figure in the front (XI direction) of the GMR element 10. It is in a possible state.
  • the pair of magnets Ml and M2 are set to have different polarities. In the case shown in Fig.
  • the XI side surface of the magnet Ml is the S pole (and hence the X2 side surface is the N pole), and the XI side surface of the magnet M2 is the N pole (and therefore the X2 side surface is the S pole). ) Are magnetized.
  • the magnet Ml is set to the first position facing the N-pole SGMR element, and as shown in FIG.
  • the S pole of the magnet M2 is set to the second position (see Fig. 5) facing the GMR element.
  • the GMR element 10 has a free layer, a fixed layer (pinned layer), and the like.
  • the solid arrow pointing in the Y2 direction in the figure indicates the direction of the bias magnetic field ml relative to the free layer
  • the white arrow pointing in the X2 direction in the figure indicates the magnetic direction e 1 of the fixed layer.
  • the direction of the bias magnetic field ml and the magnetization direction el of the fixed layer are set to be 90 degrees different from each other.
  • the magnetization direction el of the fixed layer is constant and does not change due to the external magnetic field HI or H2 supplied from the magnet Ml or M2, but the magnetization direction of the free layer depends on the external magnetic fields H1 and H2. Change.
  • both ends of the GMR element 10 have a temperature compensation of 1000 ppmZ ° C., for example. It is connected to a positive constant current source (power supply unit) 15 and supplied with a predetermined constant current I. As shown in FIG. 3, the equivalent circuit of the GMR element 10 can be expressed as a fixed resistance R and a variable resistance ⁇ R connected in series.
  • the magnetic switch has a comparison unit 18 formed of force such as a comparator, and compares the output V of the GMR element 10 with a predetermined threshold voltage Vth. I do.
  • the predetermined threshold voltage Vth is set between the maximum output voltage Vma X and the minimum output voltage Vmin as shown in FIG.
  • the comparison unit 18 outputs a switching signal composed of Ov which is switched off when V is Vth, and a switching signal composed of 5v which is switched on when V> Vth. Output.
  • a magnetic switch that operates stably can be configured.
  • the magnetic switch shown in the first embodiment can constitute a magnetic switch with one GMR element. Also, as before, large magnets and maximum energy Since it is not necessary to use a large volume of rare earth magnets, the manufacturing cost can be reduced.
  • the force described in the case of the moving magnet system in which the magnets Ml and M2 are provided and moved by the moving mechanism is provided.
  • the GMR element is provided in the moving mechanism.
  • a moving sensor type in which a magnet is provided on the yoke side may be used.
  • FIG. 7 is a perspective view showing a magnetic switch using two GMR elements as a second embodiment of the present invention
  • FIG. 8 is a circuit configuration diagram showing the configuration of the GMR element
  • FIGS. 9 and 10 are magnetic diagrams.
  • FIG. 9 is an explanatory diagram for explaining the operation of the switch.
  • FIG. 9 shows a case in the first position (in the gap G1)
  • FIG. 10 shows a case in the second position (in the gap G2).
  • Fig. 7 shows a so-called moving sensor type magnetic switch.
  • the magnet Ml magnetized (the X2 side end face is the S pole) and the magnet M2 magnetized with the XI side end face shown in the figure are therefore the S pole (and therefore the X2 end face is the N pole).
  • the magnet Ml magnetized (the X2 side end face is the S pole) and the magnet M2 magnetized with the XI side end face shown in the figure are therefore the S pole (and therefore the X2 end face is the N pole).
  • a first yoke 21 and a second yoke 22 made of a magnetic material such as ferrite are fixed to the end surfaces of the magnets Ml and M2 in the XI and X2 directions.
  • the first yoke 21 and the second yoke 22 are substantially L-shaped in cross section and have facing portions 21a and 22a protruding in the X direction in the drawing.
  • a gap G having a predetermined gap dimensional force is formed in a portion where the end surface (fixed portion) of one facing portion 21a and the end surface (fixed portion) of the other facing portion 22a face each other.
  • the gap located on the Y1 side in the figure is the gap Gl
  • the gap located on the Y2 side in the figure is the gap G2.
  • the magnetic field formed by the magnet Ml is N as much as possible of the magnet Ml.
  • the second yoke 22 ⁇ the end surface of the facing portion 22a ⁇ the gap Gl ⁇ the end surface of the facing portion 21a ⁇ the first yoke 21. It forms the first closed magnetic circuit (closed magnetic circuit) that reaches the south pole of Ml.
  • the magnetic field formed by the magnet M2 is from the north pole of the magnet M2 to the first yoke 21 ⁇ the end face of the facing portion 21a ⁇ the gap G2 ⁇ the end face of the facing portion 22a ⁇ the second yoke 22 ⁇ the S pole of the magnet M2. Is formed as a second closed magnetic circuit (closed magnetic circuit).
  • the direction of the magnetic field formed by the first closed magnetic path is opposite to the direction of the magnetic field formed by the second closed magnetic path. Therefore, the direction of the external magnetic field HI in the gap G1 is the X2 direction in the figure, and the direction of the external magnetic field H2 in the gap G2 is the XI direction in the figure.
  • a moving mechanism (not shown) that slides so as to be able to advance and retreat in the Y1 and Y2 directions.
  • a pair of GMR elements (magnetoresistance effect elements) 11 and 12 arranged in the moving direction (Y1-Y2 direction) are fixed to the tip of the moving mechanism.
  • both of the pair of GMR elements 11 and 12 are set to a first position located in the gap G1. Further, as shown in FIG. 10, when the moving mechanism moves in the Y2 direction, the pair of GMR elements 11 and 12 are set to the second position located in the gap G2.
  • the first position corresponds to the case where the pair of GMR elements 11 and 12 are placed vertically in a uniform external magnetic field HI generated by the magnet Ml.
  • the second position This corresponds to the case where the pair of GMR elements 11 and 12 are placed vertically in the uniform external magnetic field H2 generated by the magnet M2.
  • a magnetic shielding member 30 that is made of a magnetic material and covers only one GMR element 11 is provided. For this reason, the external magnetic fields HI and H2 generated by the magnets Ml and M2 can affect the other GMR element 11.
  • the magnetically shielded one GMR element 11 must have no effect. Cannot be set to the state.
  • the structures of the GMR elements 11 and 12 are the same as those of the GMR element shown in the first embodiment.
  • the GMR element 11 and the GMR element 12 are configured by cutting out any two adjacent GMR elements from a large number of GMR elements formed on the same wafer. For this reason, the GMR element 11 and the GMR element 12 match many characteristics including temperature characteristics.
  • the GMR element 11 and the GMR element 12 are connected in series, and an equivalent circuit thereof is shown in FIG. It will be shown in That is, since the one GMR element 11 that is magnetically shielded is not affected by the external magnetic fields HI and H2, it can be regarded as a fixed resistance that only has a fixed resistance R.
  • the other GMR element 12 is expressed as a fixed resistor R and a variable resistor AR connected in series as described above.
  • An output terminal 14 is drawn out from a connection portion 13 between the GMR element 11 and the GMR element 12.
  • a constant voltage source (power supply unit) 16 is connected to both ends of the GMR element 11 and the GMR element 12 connected in series, and a predetermined constant voltage VI is applied.
  • the moving mechanism when the moving mechanism is in the second position moved in the Y2 direction, that is, the pair of GMR elements 11 and 12 are both moved to the position in the gap G2.
  • the magnetic layer direction of the free layer of the GMR element 12 is directed in the XI direction that coincides with the direction of the magnetic layer direction e 1 of the fixed layer.
  • the output voltage is about 80mV, which is larger than 10mV. For this reason, even if external noise or the like is mixed, the magnetic switch is unlikely to malfunction.
  • the magnetic switch has a comparison unit 18, and compares the output V of the output terminal 14 force with a predetermined threshold voltage Vth.
  • the predetermined threshold voltage Vth is the maximum output voltage Vmax and the minimum output voltage Vmin as in FIG. Is set in the middle.
  • the comparison unit 18 outputs a switching signal consisting of Ov that is switched off, and when V> Vth, the comparing unit 18 outputs a switching signal consisting of 5v that is switched on. Output.
  • a magnetic switch that operates stably can be configured.
  • a magnetic switch having a simple configuration can be obtained by using one of the pair of GMR elements 11 as a fixed resistor.
  • one GMR element 11 used as a fixed resistance and the normal GMR element 12 are cut out from the same wafer, it is possible to match the fluctuations in resistance (temperature characteristics) caused by temperature changes. it can. For this reason, even if the temperature changes, the fluctuation range of the output V of the GMR elements 11 and 12 can be suppressed within a very small range within the potential difference ⁇ . It can be a switch.
  • the force can also be made a fixed resistance by a simple means of covering one GMR element 11 with a magnetic shielding member.
  • the GMR element 11 and the GMR element 12 can be used in a state where the magnetic field directions el of the fixed layers of the GMR element 11 and the GMR element 12 are matched.
  • the GMR elements 11 and 12 formed simultaneously on the common wafer are in a state in which the directions of the magnetic field directions el of the fixed layer coincide.
  • the GMR elements 11 and 12 cut out integrally from the wafer can be fixed to the wall surface 20 on the fixed portion side or the tip of the mobile mechanism as it is. That is, since it is not necessary to adjust the magnetization direction el of the fixed layer of the GMR element 11 and the magnetization direction e 1 of the fixed layer of the GMR element 12, the manufacturing process can be simplified.
  • the present invention provides a magnet in the moving mechanism. Ml and M2 are provided, and GMR elements 11 and 12 are provided on the yoke side.
  • FIG. 1 is a perspective view showing a magnetic switch using one GMR element as a first embodiment of the present invention
  • FIG. 2 is a plan view showing the magnetic direction of the GMR element
  • FIG. 3 is a circuit configuration diagram showing the configuration of the magnetic switch
  • FIG. 8 is a circuit configuration diagram showing the configuration of the GMR element.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Hall/Mr Elements (AREA)
  • Measuring Magnetic Variables (AREA)
  • Switches That Are Operated By Magnetic Or Electric Fields (AREA)

Abstract

La présente invention concerne un commutateur magnétique conçu pour éliminer les écarts de température et utilisant un petit nombre de composants pour limiter les dysfonctionnements. Le commutateur magnétique comprend un module fixe, un mécanisme mobile se déplaçant parallèlement au module fixe, deux aimants (M1, M2) disposés sur l'un ou l'autre du module fixe ou du mécanisme mobile et produisant des champs magnétiques externes (H1, H2) de polarités différentes, un élément à effet de magnétorésistance disposé sur l'autre composant - mécanisme mobile ou module fixe - et consistant en un élément GMR (10), un module d'alimentation qui délivre un courant déterminé à l'élément à effet de magnétorésistance et un module destiné à comparer la tension de sortie de l'élément à effet de magnétorésistance avec une valeur seuil déterminée et à produire un signal de commutation d'après les résultats de comparaison.
PCT/JP2007/050280 2006-01-13 2007-01-12 Commutateur magnetique WO2007080941A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2006005506A JP2007188739A (ja) 2006-01-13 2006-01-13 磁気スイッチ
JP2006-005506 2006-01-13

Publications (1)

Publication Number Publication Date
WO2007080941A1 true WO2007080941A1 (fr) 2007-07-19

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019091611A1 (fr) * 2017-11-09 2019-05-16 Griessbach Gmbh Interrupteur doté d'un ensemble d'aimants

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011098667A (ja) * 2009-11-06 2011-05-19 Tokai Rika Co Ltd 状態検出装置及びそれを用いたバックル装置
CN102901941B (zh) * 2012-10-24 2015-08-19 无锡乐尔科技有限公司 用于磁开关传感器的电路
RU198887U1 (ru) * 2020-04-16 2020-07-30 Андрей Юрьевич Петров Устройство переключения электрической цепи

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09311135A (ja) * 1996-05-23 1997-12-02 Mitsubishi Electric Corp 検出装置
JP2001264006A (ja) * 2000-03-17 2001-09-26 Koganei Corp 位置検出装置およびその製造方法
JP2002372403A (ja) * 2001-06-14 2002-12-26 Alps Electric Co Ltd ポジションセンサ
WO2005081007A1 (fr) * 2004-02-19 2005-09-01 Mitsubishi Denki Kabushiki Kaisha Detecteur de champ magnetique, detecteur de courant, detecteur de position et detecteur de rotation l’utilisant

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09311135A (ja) * 1996-05-23 1997-12-02 Mitsubishi Electric Corp 検出装置
JP2001264006A (ja) * 2000-03-17 2001-09-26 Koganei Corp 位置検出装置およびその製造方法
JP2002372403A (ja) * 2001-06-14 2002-12-26 Alps Electric Co Ltd ポジションセンサ
WO2005081007A1 (fr) * 2004-02-19 2005-09-01 Mitsubishi Denki Kabushiki Kaisha Detecteur de champ magnetique, detecteur de courant, detecteur de position et detecteur de rotation l’utilisant

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019091611A1 (fr) * 2017-11-09 2019-05-16 Griessbach Gmbh Interrupteur doté d'un ensemble d'aimants

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