JPH08297004A - Position-detecting apparatus - Google Patents

Abstract

PURPOSE: To obtain a position-detecting apparatus which can be easily improved in accuracy, lengthened in stroke and reduced in cost by mounting a means consisting of a permanent magnet or winding for forming a magnetic field to a part of a carriage. CONSTITUTION: A scale 1 is constituted of a pair of first yokes 2a, 2b opposed to each other via a predetermined gap, a first permanent magnet 3a for forming a first magnetic field in a space 8 forming the predetermined gap, and a second permanent magnet 3b for forming a second magnetic field in the space 8. A carriage 10 is composed of a third permanent magnet 6 for forming a third magnetic field in the space 8 and a magneto-electric conversion element 7. The first and second permanent magnets 3a and 3b are arranged so that the first and second magnetic fields formed thereby are in different directions from each other. The third permanent magnet 6 is disposed to be in the same direction as the first magnetic field and in a different direction from the second magnetic field.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention outputs a change in a continuous magnetic field of a scale corresponding to a displacement of a carriage as a change in various electric quantities such as voltage or electric resistance through various magnetoelectric conversion elements. The present invention relates to a position detection device that can easily detect displacement, length, and the like.

[0002]

2. Description of the Related Art Generally, as a position detecting device for detecting displacement or length, a position detecting device utilizing changes in various electromagnetic waves, a position detecting device utilizing changes in magnetic field, and changes in various electric quantities are used. There are position detection devices and the like.

1 and 2 show the structure of a conventional position detecting device similar to the position detecting device of the present invention which utilizes changes in the magnetic field, and FIG. 3 shows the distribution of the magnetic field.

In the conventional example shown in FIG. 1, the position detecting device mainly comprises a scale 1 and a carriage 10. The scale 1 is attached to a pair of first yokes 2a and 2b facing each other with a predetermined gap and one end of each of the first yokes 2a and 2b, and a space formed by the gap. The first permanent magnet 3a that forms the first magnetic field in a part of the inner space 8 and the other end of each of the first yokes 2a and 2b, and the second permanent magnet 3a is installed in the other part of the space 8. And a second permanent magnet 3b that forms the magnetic field. The carriage 10 constitutes a magnetic field change detecting portion corresponding to the displacement of the position, and is constituted by the magnetoelectric conversion element 7 including a Hall element or a magnetic resistance element.

First permanent magnet 3a and second permanent magnet 3b
Means that the magnetic pole surface of the first permanent magnet 3a having the N-pole polarity faces the magnetic pole surface of the second permanent magnet 3b having the S-pole polarity through the first yoke 2a. 3a S
The magnetic pole surface having the polarity of the pole is arranged so as to face the magnetic pole surface having the polarity of the N pole of the second permanent magnet 3b via the first yoke 2b. In the range from the central portion C to the end portion A in the space 8, the first yoke 2a to the first yoke 2b are provided.
A first magnetic field toward the first yoke 2a is formed in a range from the central portion C to the end portion B in the space 8 in the direction from the first yoke 2b to the first yoke 2a.

In the conventional example shown in FIG. 2, the position detecting device mainly comprises a scale 1 and a carriage 10. The scale 1 is wound around the pair of first yokes 2a and 2b, which are opposed to each other with a predetermined gap, and the first yoke 2a. And a first winding 5a that forms a second magnetic field in the other part of the space 8. Carriage 10
Constitutes a detector for detecting a change in the magnetic field corresponding to the displacement of the position, and is constituted by a magnetoelectric conversion element 7 including a Hall element or a magnetoresistive element.

The first magnetic field and the second magnetic field formed by the first winding 5a are formed in the space 8 in different directions. That is, by causing a current to flow through the first winding 5a in the direction shown in the drawing, the first yoke 2a moves from the first yoke 2a to the first yoke 2b in the range from the central portion C to the end portion A in the space 8. 1 magnetic field is formed, and in the range from the central portion C to the end portion B in the space 8, the first yoke 2b to the first yoke 2a are formed.
A second magnetic field is formed towards the.

FIG. 3 shows the magnitude of the magnetic field H [A / m] formed in the space 8 with respect to the displacement x [mm] of the carriage 10 in the conventional position detecting device shown in FIGS. 1 and 2. FIG. 4 shows changes in the distribution of the magnetic field when the carriage 10 moves from one end A of the scale 1 to the other end B thereof.

The magnetic field when the carriage 10 is located at the end A of the scale 1 is + Ha [A / m], the magnetic field when it is located at the center C is 0 [A / m], and the end B The magnetic field when positioned at is -Hb [A / m]. The magnetic field is maximum at one end A and minimum at the other end B. The straight line indicated by the dotted line shows the ideal magnetic field distribution,
The curve shown by the solid line shows the distribution of the magnetic field of the conventional position detecting device shown in FIGS.

However, in these detection methods, as shown by the solid line in FIG. 3, the distribution of the magnetic field over the entire stroke changes with a predetermined curve, and is shown by the solid line corresponding to the predetermined magnetic field Ho [A / m]. There is an error of Δx [mm] between the displacement xa [mm] of the curved line and the displacement xb [mm] of the straight line indicated by the dotted line corresponding to the predetermined magnetic field Ho [A / m]. Δx for displacement from end A to end B
When the maximum value of the percentage of [mm] is taken as the linearity, the linearity of the conventional position detecting device shown in FIGS. 1 and 2 is ± 0.5.
%, And 1 [m for a stroke of 100 [mm]
m], and the position detection device has an accuracy of 1 [mm]. When it is applied to a long stroke position detecting device exceeding 100 [mm], the linearity or accuracy is extremely deteriorated in proportion to the stroke.

[0011]

The problem to be solved is that the conventional position detecting device is expensive, and it is difficult to mount it on various general-purpose equipment such as various consumer equipment, various industrial equipment and various OA equipment. However, it is impossible to cope with long strokes in terms of price.

[0012]

SUMMARY OF THE INVENTION The present invention is most characterized in that it has means for forming a magnetic field in a carriage, and has the object of improving accuracy, improving linearity, lengthening stroke and lowering cost. Was realized extremely easily.

[0013]

Therefore, according to the position detecting apparatus of the present invention, the carriage is provided with the means for forming the third magnetic field, and the first magnetic field and the second magnetic field formed by the scale are arranged in different directions. , The third magnetic field is the first magnetic field or the second magnetic field
The magnetic field is formed in the same direction as one of the two magnetic fields, and the first magnetic field or the second magnetic field formed by the scale is integrated in the magnetoelectric conversion element that forms the carriage, thereby improving accuracy, improving linearity, and increasing longness.・ Strokes can be made. Furthermore, by superimposing the third magnetic field on the first magnetic field and the second magnetic field, the level of the magnetic field acting on the magnetoelectric conversion element can be increased. That is, the first magnetic field and the second magnetic field can be reduced, and the means for forming the first magnetic field, the means for forming the second magnetic field, and the yokes forming the magnetic path can be made small and lightweight. It realizes price reduction.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The position detecting device of the present invention will be described in detail with reference to the embodiments shown in FIGS. 4 to 9, and the distribution of its magnetic field is shown in FIGS.

FIG. 4 shows a position detecting device of the present invention in which the means for forming the first magnetic field, the means for forming the second magnetic field, and the means for forming the third magnetic field are constituted by permanent magnets. 1 shows the first embodiment.

The position detecting device of the present invention shown in FIG. 4 mainly comprises a scale 1 and a carriage 10. Scale 1
Is attached to one end of each of the pair of first yokes 2a and 2b, which are opposed to each other with a predetermined gap, and the space 8 defined by the gap.
A first permanent magnet 3a that forms a first magnetic field in a part of the inside
And a second permanent magnet 3b attached to the other end of each of the first yokes 2a and 2b and forming a second magnetic field in the other part of the space 8. Carriage 1
0 constitutes a detection part of the change of the magnetic field corresponding to the displacement of the position, and forms the third magnetic field in the space 8 by the third permanent magnet 6
And a magnetoelectric conversion element 7 including a Hall element or a magnetoresistive element. The various magnetoelectric conversion elements 7 are attached to the ends of the third permanent magnet 6 that forms a third magnetic field in the space 8 in the moving direction.

First permanent magnet 3a and second permanent magnet 3b
Are arranged so as to form a first magnetic field and a second magnetic field in different directions in the space 8, and the first magnetic field is the first magnetic field.
Is formed in the range in the direction A from the central position in the space 8 by the permanent magnet 3a, and the second magnetic field is formed in the range in the direction B from the central position in the space 8 by the second permanent magnet 3b.
The third permanent magnet 6 forms in the space 8 a third magnetic field in the same direction as either the first magnetic field or the second magnetic field.

In this embodiment, the magnetic pole surface of the first permanent magnet 3a having the N-pole polarity is opposed to the magnetic pole surface of the second permanent magnet 3b having the S-pole polarity through the first yoke 2a. The magnetic pole surface of the first permanent magnet 3a having the polarity of the S pole faces the magnetic pole surface of the second permanent magnet 3b having the polarity of the N pole via the first yoke 2b. Is located in. The first magnetic field is formed in the space 8 from the first yoke 2a toward the first yoke 2b,
The magnetic field is generated in the space 8 from the first yoke 2b toward the first yoke 2a. The magnetic pole surface having the N pole polarity of the third permanent magnet 6 faces the magnetic pole surface having the N pole polarity of the first permanent magnet 3a and the S magnetic pole surface having the S pole polarity of the second permanent magnet 3b. And the third magnetic field is formed in the same direction as the first magnetic field but in a direction different from the second magnetic field.

In FIG. 5, the means for forming the first magnetic field and the means for forming the second magnetic field are constituted by windings wound around a yoke, and the means for forming the third magnetic field is a permanent magnet. 2 shows a second embodiment of the position detecting device of the present invention configured as described above.

The position detecting device of the present invention shown in FIG. 5 mainly comprises a scale 1 and a carriage 10. Scale 1
Forms a first magnetic field in a part of the space 8 defined by the pair of first yokes 2a and 2b facing each other with a predetermined gap, and further, the configuration of the gap. The first winding 5a is wound around the first yoke 2a that forms the second magnetic field in the other part of the space 8.
The carriage 10 constitutes a detection unit for detecting a change in the magnetic field corresponding to the displacement of the position, and forms a third magnetic field in the space 8.
The permanent magnet 6 and the magnetoelectric conversion element 7 including a Hall element or a magnetoresistive element. The various magnetoelectric conversion elements 7 are attached to the ends of the third permanent magnet 6 that forms a third magnetic field in the space 8 in the moving direction.

The first winding 5a is wound around the first yoke 2a so as to form a first magnetic field and a second magnetic field in different directions in the space 8, and the first magnetic field is generated in the space 8. The second magnetic field is formed in a range in the A direction from the central position in the inside, and the second magnetic field is formed in a range in the B direction from the central position in the space 8. The third permanent magnet 6 forms in the space 8 a magnetic field in the same direction as either the first magnetic field or the second magnetic field.

In this embodiment, a current is passed through the first winding 5a in the direction shown, so that the first magnetic field causes the space 8
It is formed inside the first yoke 2a toward the first yoke 2b, and the second magnetic field is formed in the space 8 from the first yoke 2b toward the first yoke 2a. The third permanent magnet 6 has a magnetic pole surface having an N-pole polarity that is the first yoke 2
The magnetic pole surface having the polarity of the S pole is arranged so as to face a and to face the first yoke 2b, and forms a third magnetic field in the same direction as the first magnetic field but in a direction different from the second magnetic field. To do.

In FIG. 6, the means for forming the first magnetic field and the means for forming the second magnetic field are constituted by windings wound around a yoke, and the means for forming the third magnetic field is a permanent magnet. It shows a third embodiment of the position detecting device of the present invention constituted by.

The position detecting device of the present invention shown in FIG. 6 mainly comprises a scale 1 and a carriage 10. Scale 1
Is a pair of first yokes 2a and 2b arranged to face each other with a predetermined gap, and a pair of second yokes 4a and 4b fixed to both ends of the first yokes 2a and 2b.
And a first winding 5a wound around the second yoke 4a and forming a first magnetic field in a part of the space 8 defined by the gap.
And a second winding 5b wound around the second yoke 4b and forming a second magnetic field in the other part of the space 8. The carriage 10 constitutes a magnetic field change detection unit corresponding to the displacement of the position, and a magnetoelectric conversion element including a third permanent magnet 6 that forms a third magnetic field in the space 8 and a Hall element or a magnetoresistive element. It is composed of 7. The magnetoelectric conversion element 7 is attached to the end of the third permanent magnet 6 that forms the third magnetic field in the space 8 in the moving direction.

The first winding 5a is wound around the second yoke 4a so as to form the first magnetic field in the space 8, and the second winding 5b is wound in the space 8 with the first magnetic field. Second in a different direction from
Is wound around the second yoke 4b so as to form a magnetic field of. The first magnetic field is formed by the first winding 5a in the range in the A direction from the center position in the space 8, and the second magnetic field is formed by the second winding 5b in the range in the B direction from the center position in the space 8. Is formed. The third permanent magnet 6 forms in the space 8 a magnetic field in the same direction as either the first magnetic field or the second magnetic field.

In the present embodiment, a current flows through the first winding 5a in the direction shown in the drawing, whereby the first magnetic field becomes a space 8
The second magnetic field is formed in the space 8 from the first yoke 2a toward the first yoke 2b, and a current flows through the second winding 5b in the direction shown in the drawing. 2b
It is formed toward the first yoke 2a. The third permanent magnet 6 is arranged such that the magnetic pole surface having the N-pole polarity faces the first yoke 2a and the magnetic pole surface having the S-pole polarity faces the first yoke 2b. The third magnetic field is formed in the same direction as that of the second magnetic field but different from the second magnetic field.

In FIG. 7, the means for forming the first magnetic field and the means for forming the second magnetic field are constituted by windings wound around a yoke, and the means for forming the third magnetic field is a permanent magnet. The 4th Example of the position detection apparatus of this invention comprised by this is shown.

The position detecting device of the present invention shown in FIG. 7 mainly comprises a scale 1 and a carriage 10. Scale 1
Is a pair of first yokes 2a and 2b arranged to face each other with a predetermined gap, and a pair of second yokes 4a and 4b fixed to both ends of the first yokes 2a and 2b.
A first winding 5a wound around one end of the first yoke 2a and forming a first magnetic field in a part of the space 8 forming the gap; The second winding 5b is wound around the other end and forms a second magnetic field in another part of the space 8 defined by the gap. The carriage 10 constitutes a magnetic field change detection unit corresponding to the displacement of the position, and a magnetoelectric conversion element including a third permanent magnet 6 that forms a third magnetic field in the space 8 and a Hall element or a magnetoresistive element. It is composed of 7. Magnetoelectric conversion element 7
Is a third permanent magnet 6 that forms a third magnetic field in the space 8.
Is attached to the end of the moving direction.

The first winding 5a is wound around the first yoke 2a so as to form a first magnetic field in the space 8, and the second winding 5b is wound in the space 8 with the first magnetic field. Second in a different direction from
Is wound around the first yoke 2a so as to form the magnetic field of. The first magnetic field is formed by the first winding 5a in the range in the A direction from the central position in the space 8, and the second magnetic field is formed by the first winding 5b in the range in the B direction from the central position in the space 8. Is formed. The third permanent magnet 6 forms in the space 8 a magnetic field in the same direction as either the first magnetic field or the second magnetic field.

In this embodiment, a current is passed through the first winding 5a in the direction shown in the drawing, so that the first magnetic field causes the space 8
The second magnetic field is formed in the space 8 from the first yoke 2a toward the first yoke 2b, and a current flows through the second winding 5b in the direction shown in the drawing. 2b
It is formed toward the first yoke 2a. The third permanent magnet 6 is arranged such that the magnetic pole surface having the N-pole polarity faces the first yoke 2a and the magnetic pole surface having the S-pole polarity faces the first yoke 2b. The third magnetic field is formed in the same direction as that of the second magnetic field but different from the second magnetic field.

FIG. 8 shows an embodiment of the present invention in which the means for forming the first magnetic field and the means for forming the second magnetic field are constituted by permanent magnets, and the means for forming the third magnetic field are constituted by windings. The 5th Example of a position detection apparatus is shown.

The position detecting device of the present invention shown in FIG. 8 mainly comprises a scale 1 and a carriage 10. Scale 1
Is attached to one end of each of the pair of first yokes 2a and 2b, which are opposed to each other with a predetermined gap, and the space 8 defined by the gap.
A first permanent magnet 3a that forms a first magnetic field in a part of the inside
And a second permanent magnet 3b attached to the other end of each of the first yokes 2a and 2b and forming a second magnetic field in the other part of the space 8. Carriage 1
Reference numeral 0 constitutes a magnetic field change detecting section corresponding to the displacement of the position, and a magnetoelectric conversion element 7 including a third winding 9 forming a third magnetic field in the space 8 and a Hall element or a magnetoresistive element. It is composed of The various magnetoelectric conversion elements 7 are attached to the ends of the third winding 9 that forms the third magnetic field in the space 8 in the moving direction.

First permanent magnet 3a and second permanent magnet 3b
Are arranged so as to form a first magnetic field and a second magnetic field in different directions in the space 8, and the first magnetic field is the first magnetic field.
Is formed in the range in the direction A from the central position in the space 8 by the permanent magnet 3a, and the second magnetic field is formed in the range in the direction B from the central position in the space 8 by the second permanent magnet 3b.
The third winding 9 is wound so as to form a third magnetic field in the space 8 in the same direction as either the first magnetic field or the second magnetic field.

In this embodiment, the magnetic pole surface of the first permanent magnet 3a having the N-pole polarity is opposed to the magnetic pole surface of the second permanent magnet 3b having the S-pole polarity through the first yoke 2a. The magnetic pole surface of the first permanent magnet 3a having the polarity of the S pole faces the magnetic pole surface of the second permanent magnet 3b having the polarity of the N pole via the first yoke 2b. Is located in. The first magnetic field is formed in the space 8 from the first yoke 2a toward the first yoke 2b,
The magnetic field is generated in the space 8 from the first yoke 2b toward the first yoke 2a. The third magnetic field is formed in the same direction as the first magnetic field but in a direction different from the second magnetic field by causing a current to flow through the third winding 9 in the direction shown.

FIG. 9 shows a position detecting device of the present invention in which the means for forming the first magnetic field, the means for forming the second magnetic field, and the means for forming the third magnetic field are respectively constituted by windings. It shows a sixth embodiment.

The position detecting device of the present invention shown in FIG. 9 mainly comprises a scale 1 and a carriage 10. Scale 1
Is a pair of first yokes 2a and 2b arranged to face each other with a predetermined gap, and a pair of second yokes 4a and 4b fixed to both ends of the first yokes 2a and 2b.
And a first winding 5a wound around the second yoke 4a and forming a first magnetic field in a part of the space 8 defined by the gap.
And a second winding 5b wound around the second yoke 4b and forming a second magnetic field in the other part of the space 8. The carriage 10 constitutes a magnetic field change detecting section corresponding to the displacement of the position, and a magnetoelectric conversion element including a third winding 9 forming a third magnetic field in the space 8 and a Hall element or a magnetoresistive element. It is composed of 7. The magnetoelectric conversion element 7 is attached to the end of the third winding 9 that forms the third magnetic field in the space 8 in the moving direction.

The first winding 5a and the second winding 5b have a second yoke 4a and a second yoke 4a so as to form a first magnetic field and a second magnetic field in different directions in the space 8, respectively. 4b, and the first magnetic field is formed by the first winding 5a wound on the second yoke 4a in a range in the direction A from the central position in the space 8, and the second magnetic field is 2 york 4
The second winding 5b wound around b is formed in a range in the B direction from the central position in the space 8. The third winding 9 forms a third magnetic field in the space 8 in the same direction as either the first magnetic field or the second magnetic field.

In the present embodiment, the first magnetic field is supplied to the space 8 by passing a current through the first winding 5a in the direction shown in the drawing.
The second magnetic field is formed in the space 8 from the first yoke 2a toward the first yoke 2b, and a current flows through the second winding 5b in the direction shown in the drawing. 2b
It is formed toward the first yoke 2a. The third magnetic field is formed in the space 8 in the same direction as the second magnetic field but in a direction different from the first magnetic field by passing a current through the third winding 9 in the illustrated direction.

The means for forming the first magnetic field, the means for forming the second magnetic field, and the means for forming the third magnetic field of the position detecting device of the present invention are as shown in the embodiments of FIGS. 4 to 9. , A winding wound around a permanent magnet or a yoke, or the like, but it may be formed by a permanent magnet and a winding wound around the permanent magnet. It takes various forms depending on the size and the like.

The position detecting device composed only of permanent magnets has the advantages of low cost and power consumption, but on the other hand, the magnitude of the magnetic field and the distribution state of the magnetic field make the machining accuracy of the permanent magnets and the constituent members. It is difficult to make a fine adjustment, and the position detection device configured only by the winding has the advantage of enabling a fine adjustment of the magnitude of the magnetic field and the distribution state of the magnetic field. It has the drawback of requiring large power consumption. A position detecting device composed of a permanent magnet and a winding wound around the permanent magnet enables adjustment of the magnitude of the magnetic field and the distribution state of the magnetic field with a small power consumption, but is expensive. It has the drawback that

10 to 12 show the carriage 1 in the first embodiment of the position detecting apparatus of the present invention shown in FIG.
It shows a change in the magnitude of the magnetic field H [A / m] with respect to 0 displacement x [mm], and the magnetoelectric conversion element 7 constituting the carriage 10 has one end portion A of the scale 1 and the other end portion B thereof. It shows the distribution of the magnetic field formed in the space 8 when it is moved up to.

FIG. 10 shows a first permanent magnet 3a forming a first magnetic field and a second permanent magnet 3 forming a second magnetic field.
b and the third permanent magnet 6 that forms the third magnetic field are ferrite permanent magnets, and the magnetic flux generated from the first permanent magnet 3a flows through the space 8 in the first yokes 2a and 2b. With respect to the magnetic flux generated by the second permanent magnet 3b and flowing through the space 8 through the first yokes 2a, 2b, the thickness of the first yokes 2a, 2b is configured to be sufficiently thick, and the carriage 10 Shows the distribution of the magnetic field when moving from one end A of the scale 1 to the other end B thereof.

Magnetoelectric conversion element 7 constituting the carriage 10.
The magnitude of the magnetic field when is located at the end A of the scale 1 is +
Ha [A / m], the magnetic field decreases at a predetermined rate as the carriage 10 moves to the center position, and the magnitude of the magnetic field becomes 0 [A / m] at the center position. With the movement, the magnetic field decreases at a predetermined rate, and the magnitude of the magnetic field at the end B becomes −Hb [A / m].

FIG. 11 shows a first permanent magnet 3a forming a first magnetic field and a second permanent magnet 3b forming a second magnetic field.
Is a ferrite permanent magnet, the third permanent magnet 6 forming the third magnetic field is a rare earth permanent magnet, and the first permanent magnet 3a generates the first yoke 2 through the space 8
The thickness of the first yokes 2a and 2b is sufficient for the magnetic fluxes flowing through the first and second yokes 2a and 2b and the magnetic fluxes generated by the second permanent magnet 3b and flowing through the space 8 through the first yokes 2a and 2b. The carriage 10 is made thick and the carriage 10 has one end A of the scale 1.
It shows the distribution of the magnetic field when moving to the other end B.

Magnetoelectric conversion element 7 constituting the carriage 10.
Is H at the end A of the scale 1, the magnitude of the magnetic field is H
a [A / m], the magnetic field decreases at a predetermined rate as the carriage 10 moves to the end B of the scale 1, and the magnitude of the magnetic field at the magnetoelectric conversion element 7 at the end B of the scale 1 is reduced. Hb
[A / m]. The magnitude of the magnetic field when the magnetoelectric conversion element 7 is located at the center of the scale 1 is (Ha + Hb) / 2 [A
/ M].

FIG. 12 shows a first permanent magnet 3a forming a first magnetic field and a second permanent magnet 3 forming a second magnetic field.
b and the third permanent magnet 6 that forms the third magnetic field are rare earth permanent magnets, and the magnetic flux generated from the first permanent magnet 3a flows through the space 8 in the first yokes 2a and 2b. With respect to the magnetic flux generated by the second permanent magnet 3b and flowing through the space 8 through the first yokes 2a, 2b, the thickness of the first yokes 2a, 2b is configured to be sufficiently thick, and the carriage 10 Shows the distribution of the magnetic field when moving from one end A of the scale 1 to the other end B thereof.

Magnetoelectric conversion element 7 constituting the carriage 10.
Is H at the end A of the scale 1, the magnitude of the magnetic field is H
a [A / m], the magnetic field decreases at a predetermined rate as the carriage 10 moves to the end B of the scale 1, and the magnitude of the magnetic field at the magnetoelectric conversion element 7 at the end B of the scale 1 is reduced. 0
[A / m]. The magnitude of the magnetic field when the magnetoelectric conversion element 7 is located at the central portion C of the scale 1 is Ha / 2 [A / m].
Is.

The distribution of the magnetic field over the entire stroke shown in FIGS. 10 to 12 is shown as a straight line as shown in FIG.
Has extremely high linearity with respect to the distribution of the magnetic field indicated by the solid line, and has a linearity of ± 0.1% or more with respect to a stroke of 100 [mm]. It is possible to detect displacement, length, etc. with an error of [mm] or less.

In the position detecting device of the present invention, the first yoke 2a, the first yoke 2b, the second yoke 4a, the second yoke 2b, etc. are made of rolled steel for general structure or mechanical structure having a low carbon content. Composed of carbon steel or free-cutting steel, etc., it is subjected to heat treatment when high precision and high linearity are required, and it has excellent magnetic properties when high precision and high linearity is required. It is composed of electromagnetic soft steel material having characteristics.

[0050]

As described above, the position detecting device of the present invention mainly comprises a scale and a carriage, and a means for forming a third magnetic field composed of a permanent magnet or a winding is attached to a part of the carriage. As a result, cost reduction, improvement in accuracy and linearity, long stroke exceeding 100 [mm] without degrading accuracy and linearity, and non-contact between the scale section and the carriage section are achieved. Enables maintenance and longer life with non-contact,
It has the advantages that the structure is simple, the number of components is small, the structure is strong, the adjustment for calibration is easy, and the installation environment is not restricted. Furthermore, since a continuous analog signal is output, the control circuit is extremely simple, and a position detecting device with high accuracy, high linearity and low cost is realized. The position detection device can be mounted on various general-purpose devices such as various consumer devices, various industrial devices, and various OA devices that do not require accuracy of 0.1 mm or more.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of a conventional position detecting device.

FIG. 2 is a structural explanatory view of a conventional position detecting device.

FIG. 3 is a magnetic field distribution diagram of the conventional position detecting device shown in FIGS. 1 and 2.

FIG. 4 is a structural explanatory view of the first embodiment of the position detecting device of the present invention.

FIG. 5 is a structural explanatory view of a second embodiment of the position detecting device of the invention.

FIG. 6 is a structural explanatory view of a third embodiment of the position detecting device of the invention.

FIG. 7 is a structural explanatory view of a fourth embodiment of the position detecting device of the invention.

FIG. 8 is a structural explanatory view of a fifth embodiment of the position detecting device of the invention.

FIG. 9 is a structural explanatory view of a sixth embodiment of the position detecting device of the invention.

FIG. 10 is a magnetic field distribution diagram of the position detecting device of the present invention.

FIG. 11 is a magnetic field distribution diagram of the position detecting device of the present invention.

FIG. 12 is a magnetic field distribution diagram of the position detecting device of the present invention.

[Explanation of symbols]

 1 Scale 2a 1st yoke 2b 1st yoke 3a 1st permanent magnet 3b 2nd permanent magnet 4a 2nd yoke 4b 2nd yoke 5a 1st winding 5b 2nd winding 6 3rd Permanent magnet 7 Magnetoelectric conversion element 8 Space 9 Third winding 10 Carriage

Claims (1)

[Claims] 1. A pair of first yokes facing each other with a predetermined gap, means for forming a first magnetic field in a part of the space defined by the gap, and other members in the space defined by the gap. A scale mainly including a means for forming a second magnetic field in a part of the space, and a structure that can smoothly move in the space defined by the gap, and are arranged in the space defined by the gap. No. 3 magnetic field forming means, and a carriage mainly composed of at least one or more magnetoelectric conversion elements mounted on an end portion in the moving direction of the third magnetic field forming means. Position detection, wherein the first magnetic field and the second magnetic field are in different directions, and the third magnetic field is in the same direction as either the first magnetic field or the second magnetic field. apparatus.