JPH1164038A - Magnetic-type displacement detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize downsizing, simplification of structure and reduction of cost in a device for detecting relative displacement as an absolute quantity. SOLUTION: A detector 1 consisting of a magnetic resistance effect element 1a and a derive 2 to be detected comprising a magnetism generating body 2a to generate a magnetic flux are displaced relatively, thereby allowing a magnetic type displacement detecting device for generating an output according to its displacement. In the displacement detecting device having such a structure, the relative displacement direction of the devices 1 and 2, arrangement direction there with respect to the respective relative displacement direction, number of arrangement, and arrangement pitch are selected and determined.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic displacement detector used for accurately measuring an absolute displacement amount,
The present invention relates to a magnetic displacement detection device that outputs a signal corresponding to the amount of displacement by relatively displacing a detector made of a magnetoresistive element and a detector made of a magnet.

[0002]

2. Description of the Related Art Conventionally, the following are known as measuring instruments for accurately measuring the absolute displacement amount.

(1) Absolute scale method As an example of this method, as shown in FIG.
The gray code display of the digit (in FIG. 13A, a white background portion corresponds to a logical '0' and a hatched portion corresponds to a logical '1') is marked on a scale, and a detection unit corresponding to each digit is displayed. A method of reading this gray code using a head 42 having a position is known. As an example of this method, an absolute position is detected by reading a gray code of a predetermined number of digits marked on a scale displacement measuring direction. Or a vernier scale method in which multiple scales with different gray code display periods are juxtaposed along the displacement measurement direction so that the phase difference between the scales can be detected. Are known.

(2) Differential Transformer System As an example of this system, as shown in FIG. 13B, two sets of hollow coils 43 and 44 are arranged in series on the same straight line along the displacement measurement direction, A rod 45 made of a magnetic permeability material is
A method is known in which a movable amount of the core 45 with respect to the coils 43 and 44 is detected as a differential change in inductance of the coils 43 and 44 via a movable interpolating means.

(3) Potentiometer system As this system, as shown in FIG. 13C, a structure in which a contact 48 is brought into contact with a predetermined length of resistance wire 47 so as to be slidable in this displacement measurement direction. With the current flowing through the resistance wire 47, the contact 48 is slid according to the amount of displacement of the object to be measured, and the end 47 of the resistance wire 47 is moved.
A method of detecting the slide amount as a change in the voltage Vo between the contact a and the contact 48 is known.

(4) Magnetostrictive Wire Method As an example of this method, a coil 5 fixed to one end 50a of a metal wire 50 of a predetermined length as shown in FIG.
1, a detection coil 52 movably fitted to the metal wire 50, and a pulse attenuator 53 fixed to the other end 50 b of the metal wire 50. A method is known in which a magnetostrictive pulse is generated in a metal wire 50 and the displacement between the end portion 50a and the detection coil 52 is detected from the elapsed time until the magnetostriction pulse is detected by the detection coil 52. .

[0007]

However, each of these conventional displacement detection methods has the following problems to be solved.

(1) Absolute scale method Since a part of a circuit for processing a signal obtained by reading the gray code becomes complicated, it is difficult to reduce the size and cost of the displacement detection device.

(2) Differential Transformer The length of the coils 43 and 44 in the displacement measurement direction must be greater than the maximum amount of displacement that can be detected by this method. , 44 or more, the total length of the entire detector is
Only a length exceeding three times the length of 3, 44 is required, and it is difficult to reduce the size of the entire apparatus.

(3) Potentiometer method Due to the presence of a mechanical contact portion, durability is poor, and it is not suitable for use in an environment where contact resistance is a problem or in an environment where vibration is severe.

(4) Magnetostrictive Wire Method The next measurement is performed because the transmission speed of the magnetostriction is about the speed of sound and the reflected wave of the magnetostrictive pulse cannot be included in the next measurement until it is attenuated by the pulse attenuator 53. There is a problem that the detection repetition period becomes long because the time required for entering cannot be shortened. Further, a coil drive circuit, a transmission time measurement circuit, and the like are required, and the number of components constituting the displacement detection circuit is increased. As a result, the circuit configuration is complicated, and it is difficult to reduce the cost.

The present invention has been made in view of the above points, and eliminates the disadvantages of these conventional displacement detection methods, and has a simple apparatus and circuit configuration, and can be easily reduced in cost.
An object of the present invention is to provide a robust displacement detection device having no mechanical sliding portion in a detection circuit system.

[0013]

According to the present invention, a detector consisting of a magnetoresistive element and a detector consisting of a magnet for generating a magnetic flux are relatively displaced to each other in accordance with the displacement within an effective length range. In a magnetic displacement detection device configured to generate an absolute amount of output, the object to be detected is disposed parallel to the displacement measurement direction and magnetized parallel to the displacement measurement direction, and the number of the detectors is two or more. The relative displacement amount is set such that the magnetoresistive effect element is arranged perpendicular to the displacement measuring direction, and the pitch of the arrangement of the magnetoresistive effect elements is equal to or less than half the magnetization pitch of the detector. A magnetic displacement detection device capable of non-contact detection of the absolute amount of the magnetic field with a simple configuration.

The detector is arranged in parallel with the displacement measuring direction and magnetized in parallel with the displacement measuring direction. The detector has two or more magnetoresistive elements which are arranged in the displacement measuring direction. The detector is arranged at a predetermined angle and the pitch is set to be equal to or less than half the magnetized pitch of the detector.

The detector is arranged in parallel with the displacement measuring direction and magnetized in parallel with the displacement measuring direction. The detector has two or more magnetoresistive elements which are arranged with respect to the displacement measuring direction. It is arranged at a predetermined angle.

The detector is arranged in the same direction as the displacement measurement direction and is magnetized perpendicular to the displacement measurement direction. The detector has one or more magnetoresistive elements. Arrange in the same direction as the displacement measurement direction.

The detectors are arranged in the same direction as the displacement measuring direction and magnetized perpendicular to the displacement measuring direction. At least two detectors are connected in series in the same direction as the displacement measuring direction. And place it.

The detector is disposed at a predetermined inclination with respect to the displacement measurement direction, and is magnetized in the same direction as the displacement measurement direction. On the other hand, at least two sets are arranged in series at a vertical angle or at a predetermined angle and in a direction perpendicular to the displacement measurement direction.

The detector is disposed with a predetermined inclination with respect to the displacement measurement direction, and is magnetized with a predetermined inclination with respect to the displacement measurement direction. At least two sets are arranged in series in a direction perpendicular to the displacement measurement direction.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a magnetic displacement detecting device according to the present invention will be described below with reference to FIGS.

In each embodiment of the magnetic displacement detecting device according to the present invention, the waveform of the magnetization pattern can take various waveforms such as a sine waveform, a rectangular waveform, a pulse waveform, and [NS], [SN]. Represents the magnetization direction of this magnetization pattern.

Further, by relatively displacing the detector consisting of a magnetoresistive element and the detector consisting of a magnet for generating magnetic flux, the absolute amount corresponding to this displacement within the effective length range is obtained. In each embodiment according to the present invention of a magnetic displacement detecting device for generating an output (hereinafter, this magnetic displacement detecting device is referred to as a magnetic displacement detecting device), the magnetization The entire pattern (J1, J2, J3, J4,...) Is composed of the magnet group 2a, and the magnetization pattern (J1, J2, J3, J4,.
..) Are the units of the recording wavelength λ, [SN] is the magnetization direction Mn, and [NS] is the magnetization direction Ms.

First, a first embodiment of a magnetic displacement detecting apparatus according to the present invention will be described with reference to FIGS. 1A and 1B.

In the embodiment shown in FIG. 1A, 1 is a detector, 2 is a detector, and the detector 2 is, for example, Fe-
On a signal recording ferromagnetic film containing Ni as a main component, a plurality of
In this embodiment, four magnetization patterns J1,
J2, J3, and J4 are formed of a magnet group 2a formed so as to be sequentially arranged.

In order to perform this displacement measurement, the detector 2 uses an MR element S which constitutes the detector 1 described later.
,..., S8 are supported by a support (not shown) so as to be relatively displaceable with respect to the detector 1 in a direction orthogonal to each of S1, S8. Here, t is a minute interval provided to keep the detector 1 and the detector 2 in a non-contact state. In the following description, the direction in which the detector 1 and the detector 2 are relatively displaced in order to perform this displacement measurement is as follows.
It is referred to as the displacement measurement direction.

The detector 1 includes an insulating substrate 3a, a plurality of magnetoresistive elements 1a formed on the insulating substrate 3a, and terminals 92a and 92b. In the following description of each embodiment, each of the plurality of magnetoresistive elements is referred to as an MR element, and the plurality of magnetoresistive elements are collectively referred to as an MR element group. R1 is a resistor, 9
Reference numeral 2c denotes terminals, which will be described later with reference to FIG.

The MR element group 1a includes MR elements S1, S1,... Arranged on the substrate 3a with a pitch P selected at P = λ / 2 in the displacement measurement direction (Y direction shown).
, S8, and seven connecting portions C1,..., C7 for sequentially connecting each of these MR elements in series, and the upper end side of each of the MR elements S1, S2 is connected to a connecting portion C1.
, And the lower ends of the MR elements S2 and S3 are connected at a connection C2, and the upper ends of the MR elements S7 and S8 are connected at a connection C7. The lower end of the MR element S1 is connected to the terminal 92a, and the lower end of the MR element S8 is connected to the terminal 92b.

In the first embodiment of the magnetic displacement detecting device according to the present invention, the arrangement pitch P is P
= Λ / 2, and may be P ≦ λ / 2.

Next, in the first embodiment, these M
Changes in the internal resistance of the MR element group 1a when the R element group 1a and the magnet group 2a are relatively displaced in the displacement measurement direction are denoted by the same reference numerals as those in FIGS. 1A and 1B. This will be described with reference to FIG.

FIG. 2 shows the steps from the start point to the end point of this displacement when the magnet group 2a is displaced in the displacement measurement direction Y with the upper surface of the MR element group 1a being aligned with the upper surface of the MR element group 1a. ..., St16.

Referring to FIG. 2, the magnet group 2a is set in step S
When it is at t1, the magnetic flux component from the magnet group 2a that crosses the MR element S1 at right angles is not present enough to change the resistance of the MR element S1. Then, in the process in which the magnet group 2a is further displaced relative to Step St2, the magnetic flux component crossing the MR element S1 at right angles increases, and the resistance value of the MR element S1 becomes saturated. Further, when the magnet group 2a is relatively displaced from step St2 to St3, the magnetic flux component from the magnet group 2a that crosses the MR element S1 at right angles does not exist so much as to give a change in resistance to the MR element S1. The original resistance value.

Accordingly, in FIG. 2, when the relative displacement between the MR element group 1a and the magnet generator group 2a is at Step St1, the resistance values of all the MR elements constituting the MR element group 1a are in an unsaturated state, When proceeding to step St16,
Since the resistance values of all the MR elements constituting the MR element group 1a are saturated, steps St1 to St1 are performed.
The relative displacement in the displacement measurement direction between the MR element group 1a and the magnet generator group 2a over the range of 6 can be detected by converting it into a change in the magnetic resistance of the MR element group 1a.

Since the change in the resistance of the MR element is small at the positions St3, St5,..., The signals at the positions St2, St4,. Is preferred.

Further, in the first embodiment shown in FIG. 2, the arrangement pitch P has been described as P = λ / 2. However, in the first embodiment, the arrangement pitch P may be set to a small value (P ≦ λ / 2) within a range not exceeding λ / 2. In this case, the distance between the MR element group 1a and the magnet group 2a , It is possible to lower the detection limit point of the relative displacement and to increase the definition, thereby enabling more precise measurement of the relative displacement value.

Next, a second embodiment of the magnetic displacement detecting apparatus according to the present invention will be described with reference to FIG.

This second embodiment is different from the configuration shown in FIGS. 1A and 1B in that each M
The arrangement directions of the R elements S1,..., S8 are inclined by an angle θ in a clockwise direction from a direction orthogonal to the displacement measurement direction Y between the MR element group 1a and the magnetic field group 2a. It is configured so that

In FIG. 3, the angle θ and the pitch P are represented by lSin θ = S when the length of each of the MR elements S1,...
Θ is selected as follows, and the pitch P is set as P = λ / 2.
Is set to

However, in the second embodiment, the arrangement pitch P may be set within the range of P ≦ λ / 2, that is, within a range not exceeding λ / 2.

Further, in the second embodiment, the angle θ is selected to be lSin θ = S and S ≧ λ / 2, provided that the arrangement pitch P ≦ λ / 2.
May be set to be larger than the angle θ in the second embodiment, and the angle θ may be set in a counterclockwise direction with respect to the orthogonal direction.

According to the second embodiment, the MR element group 1
a of the MR elements S1,..., S8 constituting the a is inclined by an angle θ with respect to a direction orthogonal to the displacement detection direction between the MR element group 1a and the magnetic field group 2a. In this configuration, the change in the magnetic resistance of the MR element group 1a can be made to better follow the relative displacement in the displacement measurement direction between the MR element group 1a and the magnet generator group 2a. it can.

Next, a first embodiment of the amplifier of the detection signal by the magnetic displacement detection device according to the present invention will be described with reference to FIGS.
B, the same parts as those in the examples shown in FIGS. 2 and 3 are denoted by the same reference numerals, and are described with reference to FIG. 4A.

In the first embodiment of the detection signal amplifier shown in FIG. 4A, a differential amplifier OP1 and a detection signal output terminal 9 are provided.
2b, a resistor R connected between the terminal 92b and the terminal 92c.
1, a resistor R2 connected between the output terminal 92b and the inverting input (-) of the differential amplifier OP1, a resistor R3 connected between the output OUT side and the inverting input (-) of the differential amplifier OP1, plus and minus power supplies (FIG. (Not shown), a resistor R4, R5 connected in series between the resistors R4, R5, a resistor R6 connected between the non-inverting input (+) of the differential amplifier OP1, a terminal 92b, and a terminal. The detection circuit 3a is constituted by the MR element group 1a connected between the detection circuit 3a and the MR element 92a. The terminal 92a is supplied with positive power from a power source (not shown), and the terminal 92c is supplied with negative power.

The terminal 92 shown in the detection circuit 3a
If the terminals a, 92b, and 92c are replaced with the terminals 92a, 92b, and 92c of FIGS. 1A and 3, respectively, the resistance of the MR element group 1a shown in FIGS. As the relative displacement of 2a in the displacement measurement direction decreases as shown by the straight line Rmr in FIG. 4B, the signal level of the terminal 92b changes following the relative displacement, and the signal level changes. An output signal Eeo having the characteristic shown by Smr in FIG. 4C, which is obtained by converting the relative displacement of the MR element group 1a and the magnet generator group 2a in the displacement measurement direction into a signal, is obtained from the output terminal OUT.

Next, a third embodiment of the magnetic displacement detecting apparatus according to the present invention will be described with reference to FIG.

In the embodiment shown in FIG. 5, the first MR element group 1a shown by MR1 and the second M
The R element group 1a is connected in series and arranged in the Y direction which is the displacement measurement direction.
2a is pulled out, the terminal 92c is drawn out from the MR element S13 on the terminal side of MR2, and the connecting element C is connected between the MR element S13 on the terminal side of MR1 and the MR element S1 on the starting side of MR2.
0, and the terminal 92b is drawn out from the connection portion C0.

A detector 2a having the same structure as the detector described with reference to FIG.
From the state of being placed at a position overlapping
And the detector 1a are configured to be relatively displaceable in a Y direction, which is a displacement measurement direction, up to a position overlapping with MR2 indicated by L2.

The value of S and the value of the angle θ in the embodiment shown in FIG. 5 are set to be the same as those in the embodiment shown in FIG. As in the case of FIG. 3, the embodiment shown in FIG. 5 can take various values.

Next, a second embodiment of the detection signal amplifier by the magnetic displacement detection device according to the present invention will be described with the same reference numerals being given to the same portions as those shown in FIGS. 4A and 5. 6
A, B and C show and explain.

In the second embodiment of the detection signal amplifier shown in FIG. 6B, the MR element group 1a is replaced by the MR1 and the resistance R
1 is replaced with this MR2.

Next, the operation of the embodiment shown in FIG. 6B will be described. The detector 1a and the detector 2a in the displacement measurement direction Y from the range L1 to L2 in FIG.
6A, the resistance value on the MR1 side changes in a monotonically increasing direction as shown by a straight line MR1r, and the resistance value on the MR2 side decreases monotonically as shown by a straight line MR2r in FIG. 6A. The signal level at the terminal 92b changes following the relative displacement, and based on the change in the signal level, the MR element group 1a and the magnet group 2a move in the displacement measurement direction Y. An output signal Vdeo having the characteristic indicated by Sdeo in FIG. 6C obtained by converting the relative displacement into a signal is obtained from the output terminal OUT.

The output signal Vdeo is output from the MR
1 and the change M of the resistance values of the two MR element groups MR2.
Since the differential output of R1r and MR2r is obtained, the width of the change in the signal output is further enlarged as compared with the embodiment shown in FIG. 4A.

The detection circuit shown as an embodiment in FIG. 6B is different from the detector 1a and the detector 2 in the embodiment shown in FIG.
The present invention is not limited to the example of the combination a, and the MR element group 1a or two sets of the MR element alone are used as the detector 1, and the resistance value between them is relative to the displacement measurement direction. Any detection circuit configured to relatively change with displacement can be applied as the detection circuit of the embodiment shown in FIG. 6B.

Next, a fourth embodiment of the magnetic displacement detecting apparatus according to the present invention will be described with reference to FIGS. 7A and 7B.

In the embodiment shown in FIG. 7A, the detector 1
Is a non-magnetic base 91, and 1 is linearly arranged on the non-magnetic base 91 in the displacement measurement direction over a range L.
The detector 2 includes a linear MR element 92 and terminal portions 92a and 92b drawn from both ends of the MR element 92. The detector 2 includes a magnet 94 having a length Lg equal to the range L. Is done.

The detector 1 and the detector 2 are connected to the magnet 9
As shown in FIG. 7B, the magnetic flux 94a generated by the magnetic head 4 is arranged to face the detector 1 so that the magnetic flux 94a can cross the MR element 92 at right angles. It is supported by a support (not shown) so that relative displacement can be made in the displacement measurement direction Y from L1 to L2.

Next, the operation of the embodiment shown in FIG. 7A will be described.
4 from the range L1 to L in the Y direction which is the displacement measurement direction.
2, the magnetic flux from the magnet 94 crossing the straight line portion at right angles to the MR element 92 increases in proportion to the relative displacement amount. An operation is performed so that the resistance value of 92 decreases. Therefore, this MR element 92 is replaced with the MR element shown in the embodiment of FIG. 4A.
If the change in the resistance value is read instead of the element group 1a, an output Eeo obtained by converting the relative displacement in the displacement measurement direction into a signal can be obtained.

Next, a fifth embodiment of the magnetic displacement detecting apparatus according to the present invention will be described with reference to FIG. 7C and FIG. Will be described.

In the embodiment shown in FIGS. 7C and 7D, in the configuration shown in FIG.
An MR element 92m formed by linearly folding the R element a plurality of times over the range L is disposed on the nonmagnetic base 91.

Next, the operation of the embodiment shown in FIG. 7C will be described. The MR element 92m and the magnet 94 are relatively displaced in the Y direction in the same manner as in the embodiment shown in FIG. 7A. Then, the resistance value of the MR element 92m decreases in accordance with this displacement. Therefore, this MR element 92m is
The output Eeo can be obtained by replacing the MR element group 1a shown in the embodiment shown in FIG. 7A with the reading, and the change in the resistance value is converted into a signal as compared with the embodiment shown in FIGS. 7A and 7B. Thus, the signal level of the output Eeo can be increased, so that the signal-to-noise ratio (S / N) of the output Eeo can be improved as compared with the embodiment of FIGS. 7A and 7B.

Next, a sixth embodiment of the magnetic displacement detecting apparatus according to the present invention will be described with reference to FIG. 8A, in which the same parts as those of the embodiment shown in FIGS. I do.

The embodiment shown in FIG. 8A corresponds to FIGS.
A magnet 94 having a length Lg similar to that shown in FIG. 7 is disposed in the direction of displacement measurement Y to form a detector K1.
MR elements 92-1 and 92-2 in which two sets of MR elements having the same single-line structure as the MR elements 92 shown in FIGS.
The non-magnetic base 91 so as to be in this displacement measurement direction.
The detector SD is arranged above. Then, the magnetic flux is opposed to each other so as to be able to cross the MR elements 92-1 and 92-2 at a right angle, and the magnetic flux extends from the range L1 to L2 in the displacement measurement direction Y while maintaining the opposed state. FIG. 7 shows that the detector SD and the detector K1 are supported by this support (not shown) so that relative displacement can be performed.
This is the same as the embodiment shown in FIGS.

Next, the operation of the embodiment shown in FIG. 8A will be described.
When the displacement of the MR element 92-1 is relatively displaced from the range L1 to L2 in the Y direction, which is the displacement measurement direction, along the straight line MR1r shown in FIG. 6A, and the resistance of the MR element 92-2 changes along the straight line MR2r shown in FIG. 6A. Therefore, the signal level of the terminal 92b changes following the relative displacement, and based on the change in the signal level, MR element 92-1
The output Vdeo having the characteristic shown by Sdeo in FIG. 6C, in which the relative displacement of the magnet 94 and the displacement of the magnet 94 in the displacement measuring direction Y is obtained from the output terminal OUT.

Therefore, according to the embodiment shown in FIG. 8A, the structure is simplified by using a magnet having a simple structure consisting of a single-line MR element and a magnet 94, and the same structure as that shown in FIG. The effect can be achieved.

Next, a seventh embodiment of the magnetic displacement detecting apparatus according to the present invention will be described with reference to FIG. 8B, in which the same parts as those of the embodiment shown in FIG.

In the embodiment shown in FIG. 8B, a space D is provided between the MR elements 92-1 and 92-2 in the structure of the embodiment described with reference to FIG. -1 and 92-2 are provided such that the connection terminal 92b can be pulled out from the connection portion 92d, and the length Lg of the magnet 94 side is increased by the distance D. The other configuration is the same as that of the embodiment shown in FIG. 8A.

Also in this embodiment, the detector K1
The magnetic flux generated by the magnet 94 on the side is the MR elements 92-1 and 92
The detector SD and the detector K1 can be relatively displaced in the displacement measurement direction Y from the range L1 to L2 in a state where the detector SD and the detector K1 can cross at a right angle.

Therefore, according to the embodiment shown in FIG. 8B, in addition to the effect obtained by the configuration of the embodiment shown in FIG. 8A, by providing the interval D, the MR elements 92-1 and 92-2 are connected to each other. This makes it easy to form the wiring of the circuit pattern for connecting the connection portion to the connection terminal 92b.

Next, an eighth embodiment of the magnetic displacement detecting apparatus according to the present invention will be described with reference to FIG. 8C, in which the same parts as those of the embodiment shown in FIGS. I do.

The embodiment shown in FIG. 8C is an MR element 92 having a structure in which each of the MR elements 92-1 and 92-2 described with reference to FIG. 8B is replaced with the MR element 92m described with reference to FIG. 7C. Except for the configuration of -M1 and 92-M2, the configuration is the same as that of the seventh embodiment shown and described in FIG. 8B, and the operation is the same as that of the embodiment shown in FIG. 8B.

Therefore, according to the embodiment shown in FIG. 8C, in addition to the effect obtained from the structure shown in FIG.
The effects obtained by the configurations shown in C and D can be obtained.

Next, a ninth embodiment of the magnetic displacement detecting apparatus according to the present invention will be described with reference to FIG. 9A, in which the same reference numerals are given to the same parts as in the embodiment shown in FIG. 8C. .

FIG. 9A shows a magnet group 2a which is arranged with an inclination of an angle α to be described later with respect to the displacement measurement direction Y and is magnetized in a direction parallel to the displacement measurement direction Y.
The detector AS1 formed with (J1, J2,..., J6) and the magnetoresistive elements 92-M1 and 92-M2 described with reference to FIG. The detector S is disposed on the non-magnetic base 91 in a direction orthogonal to the detector S and has a width U viewed in the direction of the arrow Y and U = λ / 2.
5 shows a magnetic displacement detection device made of W1.

The initial position when the detector SW1 and the detector AS1 are relatively displaced in the displacement measurement direction Y in FIG. In Y1, the portion of the magnetizing body 2a where the magnetization direction S → N of the magnetization pattern J1 is the MR element 9
2-M2, and at the final position Y2 of this relative displacement, the portion of the magnet J2a where the magnetization direction N ← S of the pattern J6 is the MR element 92-M1
Is formed on the nonmagnetic base 91 as a continuous pattern in which the angle α is selected so that the position coincides with the following.

Next, the operation of the embodiment shown in FIG. 9A will be described. The detector SW1 and the detector AS1 are relatively displaced in the displacement measurement direction Y from the position Y1 to the position Y2. , The portion of the magnetization pattern 2a constituting the detector AS1 is M
The process sequentially shifts to the R element 92-M1. Therefore, the MR element 92
The resistance value on the -M2 side increases in proportion to this relative displacement, and the resistance value on the MR element 92-M1 side decreases in proportion to this relative displacement. The actual displacement is converted into a change in the resistance value.

In the embodiment shown in FIG. 9A, this U
Is set to U = λ / 2, but in the ninth embodiment, the value is not limited to this and may be selected so that U ≧ λ / 2.

Next, a description will be given of a tenth embodiment of the magnetic displacement detecting apparatus according to the present invention, by assigning the same reference numerals to the same parts as those shown in FIG.

In the embodiment shown in FIG. 9B, the detector having the same configuration as the detector AS1 shown and described in FIG. 9A is used, so that the detector AS1 is omitted in FIG. 9B. As shown, the magnetoresistive effect elements 92-P1 and 92-P2 provided in the detector SW1 are constituted by a single linear MR element inclined at a predetermined angle θ with respect to a direction orthogonal to the displacement measurement direction Y. And the single linear MR element 2 extends in a direction orthogonal to the displacement measurement direction Y.
The set is configured by connecting the sets in series.

The magneto-resistance effect element 92-P
Assuming that the length of each linear MR element is 1 as shown in FIG. 9B, the value of U is U = 92-P2.
Each of the single-line MR elements is arranged to be inclined at an angle θ satisfying the condition of l Sin θ = λ / 2 = U with respect to a direction orthogonal to the direction indicated by arrow Y and λ / 2. It is composed.

In the embodiment shown in FIG. 9B, this U
Is set to U = λ / 2, but in the 9B embodiment, the value is not limited to this and may be selected so that U ≧ λ / 2.

In the operation of the embodiment shown in FIG. 9B, the shapes and arrangement directions of the magnetoresistive elements 92-P1 and 92-P2 are different from those shown in FIG. 9A.
Since the operation is the same as that of FIG. 9A, the description of the operation is omitted.

Next, an eleventh embodiment of the magnetic displacement detecting apparatus according to the present invention will be described with reference to FIG. 9C, in which the same reference numerals are given to the same parts as those shown in FIG. 9B.

The embodiment shown in FIG. 9C is an MR element 92 constructed by replacing each of the MR elements 92-P1 and 92-P2 described in FIG. 9B with the MR element 92m described in FIG. 7C. Except for the configuration of -S1 and 92-S2, the configuration is the same as that of the tenth embodiment shown and described in FIG. 9B.

Therefore, in the operation of the embodiment shown in FIG. 9C, only the shapes of the magnetoresistive elements 92-P1 and 92-P2 are different from the configuration shown in FIG. 9B. Since the configuration is the same as that shown, the description of this operation is omitted.

In each of the ninth, tenth and eleventh embodiments shown and described with reference to FIGS. 9A, 9B and 9C, two sets of magnetoresistive elements are described.
In each of the tenth and eleventh embodiments, these magnetoresistive elements are not limited to two sets but may be used in combination of three or more sets.

Next, a twelfth embodiment of the magnetic displacement detecting apparatus according to the present invention will be described with reference to FIG. 10A.

The magnetic displacement detecting device shown in FIG. 10A is disposed with an inclination of an angle α to be described later with respect to the displacement measuring direction Y, and is respectively arranged in a direction parallel to the inclination of the angle α. Magnetized magnet group 2a (J1, J2, J
3 and J4) are connected in series with the magnetoresistive elements 92T-1 and 92-T2 having the same structure as the magnetoresistive elements 92-1 and 92-2 described with reference to FIG. 8A. And a detector SW2 disposed in a direction orthogonal to the displacement measurement direction Y in the above state.

In FIG. 10A, when the detector SW2 and the detector AS2 are relatively displaced in the displacement measurement direction Y in FIG. In the position Y1, the magnet group 2a
The diagonal direction perpendicular to the displacement measurement direction Y of the portion Mn of the magnetization direction S → N of the first magnetization pattern J1 is M
The position coincides with the R element 92-T2, and at the final position Y2 of this relative displacement, in the displacement measuring direction Y of the portion Ms of the magnetizing direction N ← S of the last pattern J4 of the magnet group 2a. The diagonal direction perpendicular to the MR element 9 is
The nonmagnetic base 9 is formed so as to form a continuous pattern in which the angle α is selected so that the position coincides with 2-T1.
1 is formed.

Next, the operation of the embodiment shown in FIG. 10A will be described. The detector SW2 and the detector AS2 are relatively displaced in the displacement measurement direction Y from the position Y1 to the position Y2. The portion of the magnet group 2a constituting the detector AS2 is moved from above the MR element 92-T2 to the MR element 92-T2.
The process sequentially proceeds to element 92-T1. Therefore, the MR element 92−
The resistance value on the T2 side increases in proportion to this relative displacement,
The resistance value on the MR element 92-T1 side decreases in proportion to the relative displacement, and the amount of the relative displacement in the displacement measurement direction Y is converted into a change amount of the resistance value.

Next, a thirteenth embodiment of the magnetic displacement detecting apparatus according to the present invention will be described with reference to FIG. 10B.

The magnetic displacement detecting device shown in FIG. 10B is arranged with an inclination of an angle α to be described later with respect to the displacement measuring direction Y, and is attached in a direction parallel to the inclination of the angle α. Magnetized magnet group 2a (J1, J2, J3
J4 and J5) and an MR element 92-U1, 92- having the same arrangement direction and configuration as the MR elements 92-M1, 92-M2 shown and described in FIG. 9A.
U2, an interval D provided between the MR elements 92-U1 and 92-U2, and the interval D portion, where 92-U1 and 92-U
2 in series with each other, and a signal line drawn from the series connection to the terminal 92b.

The angle α is determined by the magnet group 2a (J
1, J2, J3J4 and J5) and the MR element 92U-1,
The relative positional relationship between the MR elements constituting each of the components 92-U2 is set in the same manner as the relative positional relationship between the magnetic field group 2a and the MR elements 92T-1, 92-T2 described with reference to FIG. 10A. The angle is made.

Further, the detector SW3 and the detector AS
3 and the relative displacement in the displacement measurement direction Y,
The resistance of the MR element 92-U1 changes with respect to the MR element 92.
In order to prevent the resistance change on the -U2 side from being delayed by the interval D, the magnetization patterns J1,.
, J5 of each of the magnetization patterns in the direction orthogonal to the magnetization direction shown in FIG. 10A is a size corresponding to the interval D provided.

Therefore, in the thirteenth embodiment, the point at which the interval D is provided is followed by Tw as the dimension when seen in the direction orthogonal to the magnetization direction of the magnetization pattern. The configuration of the twelfth embodiment is the same as that of the twelfth embodiment except that the number of MR elements constituting each of 92-U1 and U2 is increased. Therefore, the operation of the thirteenth embodiment is the same as that of the twelfth embodiment shown in FIG. Since the operation is the same as that of the embodiment, the description of the operation is omitted.

FIG. 9A,..., FIG.
According to the configuration of each embodiment shown in FIG.
, U2,..., U1, U2 can be reduced in size, so that the entire magnetic displacement detection device can be configured at low cost.

In each of the twelfth and thirteenth embodiments described with reference to FIGS. 10A and 10B, the number of these magnetoresistive elements is not limited to two but may be three or more. You may do so.

Next, a third embodiment of the amplifier of the detection signal by the magnetic displacement detecting device according to the present invention will be described by assigning the same reference numerals to the same parts as those of the embodiment shown in FIG. 4A. 11 and will be described.

In the embodiment shown in FIG.
R20 is constituted by a pair of MR elements of any of the embodiments shown and described in FIGS. 9A, B, C and 10A, B, respectively.

Then, one end of these MR10 and MR20
Are connected to a terminal 92b in common, the terminal 92b is connected to a power supply + Vcc, and the other end of the MR 10 is connected to a terminal 92a.
, And the other end of the MR 20 is connected to the terminal 92c,
One end of the resistor R10 is connected to the terminal 92a, and the resistor R11
Is connected to a terminal 92c, and the other end of the resistor R10 and the other end of the resistor 11 are commonly connected to a power supply -Vcc.

The terminal 92a is connected to the inverting input terminal (-) of the differential amplifier OP1 via the resistor R20, and the terminal 92c is connected to the non-inverting terminal (+) of the differential amplifier OP1 via the resistor R21. You.

The operation of the detection circuit of the embodiment shown in FIG. 11 will be described with reference to FIGS.
With the relative displacement in the displacement measurement direction Y between these detectors and the detectors shown in FIG. 2B, the resistance values of MR10 and MR20 change, and these changes in resistance values are converted into signals. One of these signals is supplied to the inverting input terminal (-) of the differential amplifier OP1, and the other of these signals is supplied to the non-inverting input terminal (+) of the differential amplifier OP1 to be amplified. It operates so that the output Vdeo is obtained from the output terminal OUT.

Therefore, a larger output can be obtained for the relative displacement L.

Next, an embodiment to which the magnetic displacement detecting device according to the present invention is applied will be described with reference to FIG.

In the embodiment shown in FIG. 12, reference numeral 100 denotes the whole magnetic displacement detecting device,
00 is the case 101, the first frame 102A, the second
Frame portion 102B, spindle shaft 103, bearing 104, scale base 105, scale (detected object 2) 106, sensor 107 (detector 1), and circuit board 1
It consists of ten.

The case 101 is formed in a bottomed cylindrical shape with one end being an open end and the other end being a bottom. The first frame portion 102A is formed in a disk shape as a whole, and has a fitting portion fitted on the open end of the case 101 on the outer peripheral surface portion of the first frame portion 102A. The first frame portion 102A and the case 101 are fitted to the fitting portion to form a storage container for the magnetic displacement detection unit.

A receiving portion of the bearing 104 is formed at the center of the first frame portion 102A so as to penetrate the center portion, and the bearing 104 is mounted on the receiving portion. Then, the case 10 is mounted by the mounted bearing 104.
The spindle shaft 103 is supported in a state where the spindle shaft 103 can slide inside the case 101 about the central axis LL of the first.

The second frame portion 102B is mounted in a state where it is positioned in the portion from the bottomed portion to the cylindrical portion in the case 101, and the sensor 107 (the sensor 107) is attached to the surface of the second frame portion 102B facing the spindle shaft 103. The detector 1) is mounted. A scale (detected object 2) 106 is mounted on the spindle shaft 103 at a position where it can face the sensor 107 (detector 1). Further, the detection circuit illustrated and illustrated in FIG. 11 is formed on the circuit board 110 as an example.

The sensor 107 (detector 1) and scale (detector 2) 106 are used in the first embodiment,
..., In any case of using the thirteenth embodiment, installation is performed so as to maintain the relative displacement between the detector 1 and the detector 2 as described in each of the embodiments. Is done.

The first embodiment,..., Thirteenth
In the description of the embodiments, only the relative displacement between the detector 1 and the detector 2 in one direction has been described, but in each of these embodiments, the relative displacement in this one direction is described. The present invention is not limited to the displacement only, and can be applied to a case where a relative displacement is made in a direction opposite to the one direction or in both directions,
Further, it is needless to say that the present invention is not limited to the measurement of one-dimensional relative displacement, but can be applied to the measurement of relative displacement in two-dimensional or three-dimensional directions.

Furthermore, the present invention is not limited to the first embodiment,..., And the thirteenth embodiment, and can take various configurations without departing from the spirit of the present invention. Of course.

[0110]

According to the present invention, in a device for detecting relative displacement as an absolute amount, the device is of a magnetic type, so that it is non-contact and robust, and the detector uses a magnetoresistive element. The device and circuit configuration are simplified, and an inexpensive detection device can be provided. In addition, the effective length can be made longer than the entire length of the detection device, and since the detection section is made thinner, the installation space for the detection device can be reduced.

[0111]

[Brief description of the drawings]

FIG. 1A is a front view showing the configuration of a first embodiment according to the present invention. B is a side view showing the configuration of the first embodiment according to the present invention.

FIG. 2 is a diagram illustrating the operation of the first embodiment according to the present invention.

FIG. 3 is a diagram illustrating the configuration and operation of a second embodiment according to the present invention.

FIG. 4A is a diagram illustrating an example of a detection circuit applied to the present invention. FIG. 4B is a diagram for explaining a change in the resistance value of the MR element group. C is a diagram for explaining the signal output of this detection circuit.

FIG. 5 is a diagram illustrating the configuration and operation of a third embodiment according to the present invention.

FIG. 6A is a diagram illustrating a change in resistance value of the MR element group 1a. B is a diagram for explaining another example of the detection circuit applied to the present invention. C is a diagram for explaining the signal output of this detection circuit.

FIGS. 7A and 7B are diagrams illustrating the configuration and operation of a fourth embodiment according to the present invention. FIGS. 8C and 8D are diagrams for explaining the configuration and operation of the fifth embodiment according to the present invention.

FIG. 8A is a diagram illustrating the configuration and operation of a sixth embodiment according to the present invention. B is a diagram for explaining the configuration and operation of the seventh embodiment according to the present invention. C is a diagram for explaining the configuration and operation of the eighth embodiment according to the present invention.

FIG. 9A is a diagram illustrating the configuration and operation of a ninth embodiment according to the present invention. B is a diagram for explaining the configuration and operation of the tenth embodiment according to the present invention. C is the first according to the present invention.
FIG. 3 is a diagram for explaining the configuration and operation of the first embodiment.

FIG. 10A is a diagram illustrating the configuration and operation of a twelfth embodiment according to the present invention. B is a diagram for explaining the configuration and operation of the thirteenth embodiment according to the present invention.

FIG. 11 is a diagram illustrating another example of a detection circuit applied to the present invention.

FIG. 12 is a diagram illustrating an example of a mechanism of a magnetic displacement detection device applied to the present invention.

FIG. 13A is a diagram illustrating an example of a conventional displacement detection device. B is a diagram for explaining another example of the conventional displacement detection device. C is a diagram for explaining another example of the conventional displacement detection device.

FIG. 14 is a diagram illustrating another example of a conventional displacement detection device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Detector, 1a ... Magnetoresistance effect element group (MR element group), 2 ... Detector, 2a ... Magnetic body group, 100 ... Magnetic displacement detection device

Claims (7)

[Claims] A relative displacement between a detector composed of a magnetoresistive element and a detector composed of a magnet for generating a magnetic flux relative to each other within an effective length range. In the magnetic displacement detection device configured to generate an output, the detected device is disposed parallel to a displacement measurement direction and magnetized parallel to the displacement measurement direction, and the detector includes two or more magnetic resistances. Magnetic displacement detection, wherein the effect element is arranged perpendicular to the displacement measurement direction, and the pitch of the arrangement of the magnetoresistive effect element is equal to or less than half the magnetized pitch of the detector. apparatus. 2. A relative displacement between a detector composed of a magnetoresistive element and a detector composed of a magnet for generating magnetic flux, so that an absolute amount corresponding to the displacement within an effective length range is obtained. In the magnetic displacement detection device configured to generate an output, the detected device is disposed parallel to a displacement measurement direction and magnetized parallel to the displacement measurement direction, and the detector includes two or more magnetic resistances. A magnetic displacement detection device, wherein the effect element is disposed at a predetermined angle with respect to the displacement measurement direction, and the pitch is equal to or less than half the magnetization pitch of the detector. 3. The magnetic displacement detection device according to claim 2, wherein at least two sets of the detectors are connected in series in the same direction as the displacement measurement direction. 4. A relative displacement between a detector formed of a magnetoresistive element and a detector formed of a magnet for generating a magnetic flux in an effective length range. In the magnetic displacement detection device configured to generate an output, the detected device is disposed in the same direction as the displacement measurement direction, and is magnetized perpendicular to the displacement measurement direction, and the detector has at least one magnetic field. A magnetic displacement detection device having a resistance effect element and arranged in the same direction as the displacement measurement direction. 5. The magnetic displacement detection device according to claim 4, wherein at least two sets of the detectors are connected in series in the same direction as the displacement measurement direction. 6. A relative displacement between a detector made of a magnetoresistive element and a detector made of a magnet for generating a magnetic flux in an effective length range. In the magnetic displacement detection device configured to generate an output, the detected device is disposed with a predetermined inclination with respect to a displacement measurement direction, and is magnetized in the same direction as the displacement measurement direction. A magnetic displacement detecting device, wherein at least two pairs of resistance effect elements are arranged perpendicularly or at a predetermined angle to the displacement measurement direction and at least two pairs are arranged in series in a direction perpendicular to the displacement measurement direction. 7. An absolute amount corresponding to the displacement within an effective length range by relatively displacing a detector constituted by a magnetoresistive element and a detector constituted by a magnet for generating magnetic flux. In the magnetic displacement detection device configured to generate an output, the detector is disposed with a predetermined inclination with respect to the displacement measurement direction, and is magnetized with a predetermined inclination with respect to the displacement measurement direction, A magnetic displacement detection device according to claim 1, wherein at least two pairs of the detectors are arranged in a direction perpendicular to the displacement measurement direction and at least two sets are arranged in series.