JP2016057174A - Linear sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a linear sensor which can simplify the structure of a magnetic member adjacent to a detector having magnetic poles.SOLUTION: A linear sensor 100 comprises: a stator 20 having an excitation magnetic pole 22 and detection magnetic poles 21, 23; and a scale plate 10 which is arranged so as to face the excitation magnetic pole 22 and the detection magnetic poles 21, 23, and which can be displaced relatively to the stator 20. The scale plate 10 includes: a substrate 11 formed from a non-magnetic material; and a layered magnetic layer 12 which is formed from a magnetic material, and which is provided on the substrate 11 along displacement directions D1 and D2 of the scale plate 10. The excitation magnetic pole 22 is arranged so as to face the magnetic layer 12, while the detection magnetic poles 21, 23 are arranged so as to face edge parts 12a, 12b of the magnetic layer 12. The edges 12a, 12b of the magnetic layer 12 are formed so as to displace portions that are positioned opposite the detection magnetic poles 21, 23 in a transverse direction of the displacement directions D1 and D2 when the scale plate 10 is displaced.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a linear sensor.

  Examples of the linear sensor include a magnetic linear sensor as described in Patent Document 1. This linear sensor includes a stator having a plurality of magnetic poles around which a stator winding is wound, and a mover that is linearly reciprocable adjacent to the stator. The mover is formed by connecting a plurality of cores obtained by laminating a plurality of plate-like core pieces formed by pressing a magnetic material into a long shape. The side part of the long movable element has a shape in which peaks and valleys are alternately arranged. When the mover is reciprocated linearly with the sides having crests and troughs facing the magnetic poles of the stator, the degree of magnetic coupling between the magnetic poles and the mover changes, and the two-phase An output signal is generated on the stator winding. By detecting this signal, the position of the mover relative to the stator is determined.

Japanese Patent Laying-Open No. 2003-194583

  The magnetic member, which is a mover in Patent Document 1, has a complicated structure. For its manufacture, a core piece is manufactured by pressing a magnetic material, a core is manufactured by laminating plate-like core pieces, and a plurality of magnetic members are manufactured. The cores need to be connected and a large number of manufacturing steps are required.

  The present invention has been made to solve such problems, and an object thereof is to provide a linear sensor that simplifies the structure of a magnetic member adjacent to a stator as a detector having a magnetic pole.

  In order to solve the above-described problems, a linear sensor according to the present invention is provided with a detector having an excitation magnetic pole and a detection magnetic pole, and opposed to the excitation magnetic pole and the detection magnetic pole, and can be displaced relative to the detector. The magnetic member includes a substrate formed of a nonmagnetic material, and a layered magnetic body formed on the substrate along the displacement direction and formed of the magnetic material, Is arranged so as to face the magnetic body, and the detection magnetic pole is arranged so as to face the edge of the magnetic body. When the magnetic member is displaced, the edge of the magnetic body displaces the portion facing the detection magnetic pole. It is formed so as to be displaced in the transverse direction.

The detector may have a plurality of detection magnetic poles so as to sandwich the excitation magnetic pole, and the detection magnetic poles may be arranged to face each of a plurality of edges located in the transverse direction of the displacement direction of the magnetic body.
The magnetic body may be a thin film formed on the substrate.
The magnetic body may be a magnetic sheet or a magnetic tape attached on the substrate.

  According to the linear sensor according to the present invention, the structure of the magnetic member adjacent to the detector having the magnetic pole can be simplified.

It is a typical perspective view of the linear sensor which concerns on Embodiment 1 of this invention. It is a typical perspective view of the scale board of FIG. It is a typical perspective view of the linear sensor which concerns on Embodiment 2 of this invention. It is a typical perspective view of the scale board of FIG.

A linear sensor according to an embodiment of the present invention will be described below with reference to the accompanying drawings.
Embodiment 1 FIG.
Referring to FIG. 1, a linear sensor 100 according to Embodiment 1 of the present invention detects the displacement of an object that reciprocates linearly. The linear sensor 100 includes a scale plate 10 that is a magnetic member provided so as to be capable of reciprocating along the directions D1 and D2, which are the longitudinal direction, and a stationary detector for detecting the relative position of the scale plate 10 in the longitudinal direction. The stator 20 is provided. The direction D1 and the direction D2 are opposite to each other. The scale plate 10 is fixed to an object that reciprocates linearly in the directions D1 and D2, and the stator 20 is fixed to a non-moving object.

  The stator 20 is disposed above the scale plate 10 with an interval. The stator 20 integrally has three magnetic poles 21, 22 and 23 arranged side by side along a direction perpendicular to the directions D1 and D2. Each of the magnetic poles 21, 22 and 23 is made of a magnetic material and extends so as to protrude toward the scale plate 10, and the extending direction around the cores 21a, 22a and 23a is centered. And windings 21b, 22b, and 23b. The stator 20 is arranged so that the tips of the cores 21a, 22a and 23a and the windings 21b, 22b and 23b face the scale plate 10. Further, the winding 22b located at the center constitutes an exciting winding for excitation, and the windings 21b and 23b located on both sides of the winding 22b constitute a detection winding for signal detection. The magnetic pole 22 constitutes an exciting magnetic pole for excitation, and the magnetic poles 21 and 23 constitute a detection magnetic pole for signal detection.

  Referring to FIGS. 1 and 2 together, the scale plate 10 is formed of a non-magnetic material and has a rectangular planar shape that forms the outer shape of the scale plate 10, and is formed of a magnetic material and is formed of the magnetic material. It has a magnetic layer 12 made of a thin layer directly formed over the entire longitudinal direction of the substrate 11 on one flat surface 11a. Here, the magnetic layer 12 constitutes a magnetic material.

  The magnetic layer 12 is formed by baking the surface 11a of the substrate 11 by applying a magnetic material, vapor-depositing the magnetic material by CVD (chemical vapor deposition), PVD (physical vapor deposition), or the like, or curing the magnetic metal-containing resin. It can be directly formed by thin film formation by, adhesion of magnetic sheet / magnetic tape, welding, adhesion by brazing or the like. As the magnetic sheet / magnetic tape, an adhesive such as permalloy tape may be used.

  In the magnetic layer 12, the distance between one side portion 11b along the longitudinal direction of the substrate 11 and the linear edge portion 12a along the longitudinal direction of the magnetic layer 12 adjacent to the side portion 11b is along the direction D1. It is formed so that it gradually becomes wider. That is, the edge part 12a has a fixed angle with respect to the side part 11b and the direction D1. Further, in the magnetic layer 12, the distance between the other side portion 11c along the longitudinal direction of the substrate 11 and the linear edge portion 12b along the longitudinal direction of the magnetic layer 12 adjacent to the side portion 11c is in the direction D1. It is formed so as to become gradually narrower along. That is, the edge part 12b has a fixed angle with respect to the side part 11c and the direction D1. Therefore, the magnetic layer 12 has a parallelogram planar shape.

In the stator 20, when the scale plate 10 is moved along the directions D1 and D2, the entire core 22a of the excitation magnetic pole 22 always faces the magnetic layer 12, and the core 21a of the detection magnetic pole 21 is the edge of the magnetic layer 12. The core 23a of the detection magnetic pole 23 is disposed and configured so as to face the edge 12b of the magnetic layer 12. When the core 22a is projected onto the magnetic layer 12, the entire core 22a is included in the magnetic layer 12, and when the cores 21a and 23a are projected onto the magnetic layer 12, the cores 21a and 23a are on the edges 12a and 12b, respectively. Located in.
The excitation winding 22b is connected to an AC signal generation source. The detection windings 21b and 23b are connected to a conversion device such as an R / D converter that converts electrical signals as position data and outputs them.

  When the linear sensor 100 detects the relative position of the scale plate 10 with respect to the stator 20, an AC signal is supplied to the excitation winding 22 b of the stator 20. As a result, a magnetic flux that passes around the excitation winding 22b and passes through the core 22a is generated, and this magnetic flux enters the magnetic layer 12 of the scale plate 10 to form a magnetic flux therein. The magnetic flux inside the magnetic layer 12 forms a magnetic flux extending from the magnetic layer 12 into each of the cores 21a and 23a.

  When the scale plate 10 moves in the direction D1, the portion of the core 21a that faces the magnetic layer 12 increases, so that the magnetic flux in the core 21a increases, thereby causing an induced current as an output signal in the detection winding 21b. Occur. Further, since the portion of the core 23a facing the magnetic layer 12 is reduced, the magnetic flux in the core 23a is reduced, thereby causing an induced current as an output signal having a phase different from that of the detection winding 21b to the detection winding 23b. Will occur. A converter (not shown) detects the positional relationship in the direction perpendicular to the direction D1 between the cores 21a and 23a and the edges 12a and 12b of the magnetic layer 12 from the output signals of the detection windings 21b and 23b. Thereby, the displacement in the longitudinal direction of the substrate 11 and the magnetic layer 12 with respect to the cores 21a and 23a is detected.

On the other hand, when the scale plate 10 moves in the direction D2, the magnetic flux in the core 21a decreases and the magnetic flux in the core 23a increases, so that output signals having different phases are generated in the detection windings 21b and 23b. A converter (not shown) detects displacement in the longitudinal direction of the substrate 11 and the magnetic layer 12 with respect to the cores 21a and 23a from the output signals of the detection windings 21b and 23b.
Therefore, the linear sensor 100 determines the positional relationship in the transverse direction perpendicular to the directions D1 and D2 between the cores 21a and 23a of the detection magnetic poles 21 and 23 in the stator 20 and the magnetic layer 12, and the detection windings 21b and 23b. By detecting from the output signal, the displacement of the scale plate 10 in the longitudinal direction relative to the stator 20 is detected.

  As described above, the linear sensor 100 according to the first embodiment of the present invention includes the stator 20 having the excitation magnetic pole 22 and the detection magnetic poles 21 and 23 having the windings 21b, 22b, and 23b, the excitation magnetic pole 22 and the detection magnetic pole 21, 23, and a scale plate 10 that is disposed so as to face the stator 23 and is relatively displaceable with respect to the stator 20. The scale plate 10 includes a substrate 11 formed of a nonmagnetic material, and a layered magnetic layer 12 provided on the substrate 11 along the displacement directions D1 and D2 of the scale plate 10 and formed of a magnetic material. The excitation magnetic pole 22 is disposed so as to face the magnetic layer 12, and the detection magnetic poles 21, 23 are disposed so as to face the edges 12 a, 12 b of the magnetic layer 12, respectively. The edges 12a and 12b of the magnetic layer 12 are formed to displace portions facing the detection magnetic poles 21 and 23 in the transverse direction of the displacement directions D1 and D2, respectively, when the scale plate 10 is displaced.

  At this time, when the scale plate 10 is displaced, the portions facing the detection magnetic poles 21 and 23 in the edge portions 12a and 12b are displaced in the transverse direction of the displacement directions D1 and D2, so that the excitation magnetic pole 22 passes through the magnetic layer 12. The magnetic flux formed on the detection magnetic poles 21 and 23 changes. Due to this change in magnetic flux, an output signal is generated in the windings 21b and 23b of the detection magnetic poles 21 and 23, and the displacement of the scale plate 10 relative to the stator 20 is detected from this output signal. Since the scale plate 10 has a structure in which a layered magnetic layer 12 formed of a magnetic material is provided on a substrate 11 formed of a nonmagnetic material, the structure is simple and the edge of the magnetic layer 12 is It is also easy to configure the parts 12a and 12b as described above. Thereby, the scale board 10 enables simplification of structure and manufacture, thickness reduction, size reduction, weight reduction, and cost reduction.

  Further, in the linear sensor 100, the stator 20 has detection magnetic poles 21 and 23 so as to sandwich the excitation magnetic pole 22, and the detection magnetic poles 21 and 23 are two in the transverse direction of the displacement directions D1 and D2 in the magnetic layer 12. It arrange | positions so that it may oppose each edge 12a and 12b. As a result, the linear sensor 100 detects the displacement of the scale plate 10 relative to the stator 20 from the relative positions of the two edges 12a and 12b and the detection magnetic poles 21 and 23. Therefore, the detection accuracy of the displacement of the scale plate 10 is improved.

  In the linear sensor 100, the magnetic layer 12 is a thin film formed on the substrate 11. Alternatively, the magnetic layer 12 is a magnetic sheet or a magnetic tape attached on the substrate 11. This facilitates the formation of the magnetic layer 12 on the substrate 11. Furthermore, since the planar shape of the magnetic layer 12 can be set to an arbitrary shape, the shape of the substrate 11 can be changed such as when the substrate 11 has a curved planar shape or a refracted planar shape. Regardless, the magnetic layer 12 can be formed. As a result, the linear sensor 100 can detect the displacement of the scale plate not only when the scale plate 10 is displaced along a straight line but also when the scale plate 10 is displaced along a curve, a circumference, a broken line, or the like.

Embodiment 2. FIG.
The linear sensor 200 according to the second embodiment of the present invention is obtained by changing the planar shape of the magnetic layer 12 formed on the scale plate 10 with respect to the linear sensor 100 according to the first embodiment.
In the following embodiments, the same reference numerals as those in the previous drawings are the same or similar components, and thus detailed description thereof is omitted.
3 and 4 together, the linear sensor 200 includes a scale plate 210 that can reciprocate along directions D1 and D2, and a stator 20.

  The scale plate 210 has a rectangular planar shape formed of a nonmagnetic material and a magnetic layer 212 formed of a magnetic material and formed on the surface 11a of the substrate 11 in the same manner as in the first embodiment. 213 and 214.

  The magnetic layers 212, 213, and 214 are adjacent to each other with a space therebetween and are formed over the entire length of the substrate 11. The magnetic layer 213 has a rectangular planar shape. A gap g1 between the longitudinal edges 212a of the adjacent magnetic layers 212 and the longitudinal edges 213a of the magnetic layers 213 gradually increases along the direction D1. A gap g2 between the longitudinal edges 213b of the adjacent magnetic layers 213 and the longitudinal edges 214a of the magnetic layers 214 becomes gradually narrower along the direction D1. The edges 212a and 214a have a fixed angle with respect to the edges 213a and 213b and the direction D1, respectively.

  In the stator 20, when the scale plate 210 is moved along the directions D 1 and D 2, the entire core 22 a of the excitation magnetic pole 22 always faces the magnetic layer 213, and the core 21 a of the detection magnetic pole 21 is the edge of the magnetic layer 212. The core 23a of the detection magnetic pole 23 is configured to face the edge 214a of the magnetic layer 214 so as to face the 212a. When the core 22 a is projected onto the magnetic layer 213, the entirety is included in the magnetic layer 213, and when the core 21 a is projected onto the magnetic layer 212, the core 21 a is positioned on the edge 212 a and the core 23 a is placed on the magnetic layer 214. The core 23a is positioned on the edge 214a.

  Therefore, when an AC signal is supplied to the excitation winding 22b of the stator 20, a magnetic flux passing through the core 22a is generated, and this magnetic flux enters the magnetic layer 213 of the scale plate 210 to form a magnetic flux inside. The magnetic flux inside the magnetic layer 213 forms a magnetic flux extending from the magnetic layer 213 into each of the magnetic layers 212 and 214 on both sides. The magnetic flux in the magnetic layers 212 and 214 further forms a magnetic flux extending inside each of the opposing cores 21a and 23a.

  For this reason, when the scale plate 210 moves in the direction D1, the portion of the core 21a facing the magnetic layer 212 increases, so that the magnetic flux in the core 21a increases. Moreover, since the site | part facing the magnetic layer 214 in the core 23a reduces, the magnetic flux in the core 23a reduces. As a result, output signals having different phases are generated in the detection windings 21b and 23b. A converter (not shown) detects displacements in the longitudinal direction of the substrate 11 and the magnetic layers 212 and 214 with respect to the cores 21a and 23a from the output signals of the detection windings 21b and 23b.

  On the other hand, when the scale plate 210 moves in the direction D2, the magnetic flux in the core 21a decreases and the magnetic flux in the core 23a increases, so that output signals having different phases are generated in the detection windings 21b and 23b. A converter (not shown) detects displacements in the longitudinal direction of the substrate 11 and the magnetic layers 212 and 214 with respect to the cores 21a and 23a from the output signals of the detection windings 21b and 23b.

Moreover, since the other structure and operation | movement of the linear sensor 200 which concern on Embodiment 2 of this invention are the same as that of Embodiment 1, description is abbreviate | omitted.
And according to the linear sensor 200 in Embodiment 2, the effect similar to the linear sensor 100 of the said Embodiment 1 is acquired.

  In the scale plates 10 and 210 of the linear sensors 100 and 200 of the first and second embodiments, the edges 12a and 12b of the magnetic layer 12, the edge 212a of the magnetic layer 212, and the edge 214a of the magnetic layer 214 are straight lines. However, it is not limited to this. The edges 12a, 12b, 212a, 214a need not be parallel to the directions D1 and D2, and may be broken lines, curves, or the like.

  In the linear sensors 100 and 200 according to the first and second embodiments, the entire core 22a of the stator 20 is configured to face the magnetic layers 12 and 212 of the scale plates 10 and 210. It is not limited to. When the scale plates 10 and 210 are moved, the core 22a may have an area that faces the magnetic layers 12 and 212, that is, a projected area on the magnetic layers 12 and 212 does not change. Thereby, even if the scale plates 10 and 210 move, the magnetic flux formed in the magnetic layers 12 and 212 does not change.

  In the scale plates 10 and 210 of the linear sensors 100 and 200 of the first and second embodiments, the two edges 12a and 12b of the magnetic layer 12, or the edge 212a of the magnetic layer 212 and the edge 214a of the magnetic layer 214 are used. The two detection magnetic poles 21 and 23 are provided so as to face each other, but the present invention is not limited to this. Three or more detection magnetic poles may be provided, and the edge portion of the magnetic layer facing each detection magnetic pole may be formed. Alternatively, the number of detection magnetic poles may be one.

  In the linear sensors 100 and 200 according to the first and second embodiments, the stator 20 is fixed and the scale plates 10 and 210 are movable. However, the present invention is not limited to this, and the stator is not limited thereto. 20 may be movable along the longitudinal direction of the scale plates 10 and 210, and the scale plates 10 and 210 may be fixed.

  10, 210 Scale plate (magnetic member), 11 substrate, 12, 212, 213, 214 magnetic layer (magnetic material), 12a, 12b, 212a, 214a edge, 20 stator (detector), 21, 23 detection magnetic pole, 21a, 22a, 23ab Core, 21b, 22b, 23b Winding, 22 Excitation magnetic pole, 100, 200 Linear sensor, D1, D2 Movement direction (displacement direction).

Claims (4)

For linear sensors,
A detector having an excitation magnetic pole and a detection magnetic pole;
A magnetic member provided opposite to the excitation magnetic pole and the detection magnetic pole and displaceable relative to the detector;
The magnetic member includes a substrate formed of a nonmagnetic material, and a layered magnetic body provided on the substrate along a displacement direction and formed of a magnetic material,
The exciting magnetic pole is disposed so as to face the magnetic body,
The detection magnetic pole is disposed to face the edge of the magnetic body,
The edge part of the said magnetic body is a linear sensor formed so that the part which opposes the said detection magnetic pole may be displaced to the cross direction of the said displacement direction, if the said magnetic member displaces. The detector has a plurality of the detection magnetic poles so as to sandwich the excitation magnetic pole,
The linear sensor according to claim 1, wherein the detection magnetic pole is disposed so as to face each of the plurality of edges positioned in a transverse direction of the displacement direction of the magnetic body.   The linear sensor according to claim 1, wherein the magnetic body is a thin film formed on the substrate.   The linear sensor according to claim 1, wherein the magnetic body is a magnetic sheet or a magnetic tape attached on the substrate.

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