JP3510075B2 - Method of magnetizing magnetic material and magnetic potentiometer using the magnetic material - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of magnetizing a magnetic body for magnetizing four or more magnetic poles and a magnetic potentiometer.

[0002]

2. Description of the Related Art A conventional magnetic potentiometer is a Hall element for detecting a magnetic field (magnetic flux, magnetic force) of only a normal component, a semiconductor magnetoresistive device on a side surface of a disk-shaped ferromagnetic material saturated in an air-core coil. A type in which a magnetic detection element such as an effect element is provided and the output of the magnetic detection element is taken out is known.

FIG. 6 is an explanatory view showing the concept of a general magnetic potentiometer, and FIG. 7 is an explanatory view showing the principle of the Hall element of FIG. In FIG. 6, reference numeral 1 denotes a rotating body which is rotatably supported by a frame body (not shown). The rotating body 1 is provided on a disk-shaped ferromagnetic body 2 and a ferromagnetic body 2 so as to project from the frame body (not shown). It is composed of a protruding operating shaft portion 3.
This ferromagnetic material 2 is formed by an air-core coil 1 which will be described later.
A pair of N and S poles are magnetized, and a Hall element 4 for detecting magnetic flux from the N and S poles of the rotating ferromagnetic body 2 is arranged. This Hall element 4 detects only the magnetic flux of the normal component of the ferromagnetic body 2, and FIG. 7 shows a general circuit diagram of the Hall element 4. In FIG.
Is a power source, and 6 is a voltmeter for detecting the Hall voltage generated by the Hall element 4 detecting the magnetic flux of the normal component.

FIG. 8 is a circuit diagram of a general magnetic potentiometer. In this figure, 4 is a Hall element, 7 is an amplifier,
Reference numeral 8 is a gain adjusting unit, 9 is an amplifier, and 10 is a temperature compensating unit. The voltage Vcc is applied to the hall element 4, and the hall voltage generated in the hall element 4 described above is amplified, gain adjusted, and temperature compensated through a circuit such as the amplifier 7, and Vo
ut is output.

Next, a method of magnetizing the ferromagnetic material will be described. FIG. 9 is an explanatory diagram showing the magnetization of the ferromagnetic substance by the core-air coil, and FIG. 10 is an explanatory diagram showing the magnetized state of the ferromagnetic substance by the method of FIG. In these figures, 2
Is a disk-shaped ferromagnetic body having a through hole formed in the center, 11 is an air-core coil for magnetization, and 12 is a power source connected to the air-core coil 11. As shown in FIG. When the ferromagnetic material 2 is housed in 11 and a direct current is applied, the air-core coil 1
A magnetic flux φ is generated at 1, and as shown in FIG. 10, the N and S poles are magnetized on the outer peripheral surface of the ferromagnetic body 2 at an angle of 180 °. When the ferromagnetic body 2 is saturated and magnetized in the air-core coil 11 as described above, the magnetic body 2 is magnetized substantially in parallel, so that the normal component of the magnetic field emitted from the ferromagnetic body 2 is Except around the inflection point, it increases linearly. That is, since the ferromagnetic material 2 is saturated with magnetization, the ferromagnetic material 2
This is because the magnetization intensity of does not change at any position, but when the ferromagnetic body 2 is rotated, only the normal component of the ferromagnetic body 2 with respect to the Hall element 4 changes.

[0006]

By the way, in the prior art, the N-pole and the S-pole of the ferromagnetic body 2 are placed at positions 180 degrees opposite to each other.
Only the poles can be magnetized, and the output peaks at the positions of the N and S poles. Therefore, the operation shaft portion 3 of the magnetic potentiometer
When the type with a small effective rotation angle is used, it is necessary to use a magnet with a large energy product in order to obtain an output equivalent to the conventional one. (Because the output peak is determined only by the saturation magnetization density of the magnetic substance. ), For that purpose, it is necessary to change the material of the ferromagnetic body 2, but the cost becomes high.
In particular, when the effective rotation angle is reduced, that is, when it is used in a narrow range, it is not suitable for increasing the output in that range.

Further, there is a method of magnetizing the ferromagnetic material 2 by so-called yoke magnetization. In this method, magnetic poles can be formed at a predetermined pitch, and the magnetic material is saturated even in a narrow range. An output according to the magnetization density can be obtained. FIG. 11 is an explanatory view for magnetizing with 8 poles, and 13 is a yoke having a storage portion for storing a ferromagnetic material,
Reference numeral 14 is a hole portion that penetrates an electric wire (coil) 15 formed at eight locations in the housing portion of the yoke 13 at equal intervals. One electric wire 15 is drawn around and fitted in each of the holes 14, 14. Further, each hole 14, 14 is communicated with the storage portion in a slit shape. Then, by applying a direct current to the electric wire 15, a magnetic flux is generated as shown in FIG. 11, and the magnetic flux magnetizes the N and S poles of the ferromagnetic body 2. Further, although not shown, the N and S poles are also magnetized by the magnetic flux of the electric wire 15 in the other holes 14, and eventually, the N and S poles are alternately magnetized into 8 poles on the peripheral surface of the ferromagnetic body 2. It However, in the conventional yoke magnetization method, the ferromagnetic body (magnetized body) 2
Since the wire 15 is disposed in the hole 14 of the yoke 13 so as to come into contact therewith and is magnetized, it is close to the peripheral surface of the ferromagnetic body 2.
Position (that is, an electric wire in contact with the peripheral surface of the ferromagnetic body 2)
Since a magnetic field (see FIG. 11 or FIG. 5 (a) described later) is formed around the center of 15) , the characteristic of the Hall voltage Vout and the operating angle of the rotating shaft by the magnetic potentiometer using this is linearity. The (linearity) was poor and the rotation angle could not be detected accurately.

An object of the present invention is to provide a method of magnetizing a magnetic body which is excellent in linearity in a predetermined angle range and can obtain a high output, and a magnetic potentiometer using the magnetic body. is there.

[0009]

Means for Solving the Problems The above-mentioned problems are a ferromagnetic material having a disk shape saturated with magnetization and provided with four or more magnetic poles in a plan view, and a ferromagnetic material disposed on a peripheral side surface of the ferromagnetic material. A magnetic detection element for detecting the magnetic force of the normal component of the ferromagnetic material,
The distance between adjacent magnetic poles of the ferromagnetic disk is A,
Magnetize the ferromagnetic material at a position distant from the peripheral surface of the disk.
The first magnetization center before a line connecting the centers of the ferromagnetic material from which
Assuming that the distance between the intersection of a line connecting adjacent magnetic poles and the first magnetization center is B, the first magnetization center is
B / A = 0.5 to 1.0 (where A is smaller than the radius of the ferromagnetic material) is set apart from the disk peripheral surface and is a magnetized ferromagnetic material. It can be solved by means. The object is achieved, in the first means, the other second magnetization center adjacent to the first magnetization centers of magnetic poles magnetized away from the disc peripheral surface, at a position close to the disc periphery < The problem can be solved by the second means, which is a magnetized ferromagnetic material. The task is to separate the disk-shaped ferromagnetic material from the disk circumferential surface.
The first magnetization center that magnetizes the ferromagnetic material at the
And magnetize the ferromagnet at a position close to the disk surface.
Second magnetization centers become previously provided was the yoke a coil that
As well as housing the serial ferromagnetic, and the line connecting the said disc of ferromagnetic material the distance between adjacent magnetic poles is A, and adjacent line connecting the centers of the ferromagnetic from the first magnetization center pole Where B is the distance between the intersection and the first magnetization center, the first magnetization center is at a position where B / A = 0.5 to 1.0 (where A is a ferromagnetic material). Smaller than the radius of
It is possible to solve the problem by the third means which is set apart from the disk peripheral surface of the ferromagnetic material and magnetized. The above problem can be solved by a fourth means in the third means, wherein the yoke has a tapered surface that spreads from the first magnetization center toward the disk peripheral surface of the ferromagnetic body. In the third means, in the third means, another object adjacent to the first magnetization center is provided.
The second magnetization center can be solved by the fifth means magnetized at a position close to the disk peripheral surface.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view showing a ferromagnetic material of an embodiment of a magnetic potentiometer according to the present invention, and FIGS. 2 (a), 2 (b) and 2 (c) are a plan view and a front view showing a yoke used for magnetization. Figure and enlarged view of wire insertion hole, FIG. 3 is an explanatory view showing the relationship between a ferromagnetic material and an electric wire, FIG. 4 is a view showing characteristics of linearity and distance ratio in FIG. 3, and FIG. 5 is (a), (b) [Fig. 4] is an explanatory diagram showing a state of magnetic flux when the electric wire is magnetized in a state where the electric wire is in contact with the ferromagnetic body and a state where the electric wire is separated from the ferromagnetic body. The same parts as those in the conventional example are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 1 shows a ferromagnetic material which can be used when the effective rotation angle of the magnetic potentiometer is reduced. The ferromagnetic body 20 is disc-shaped and has a through hole formed in the center thereof. Further, the ferromagnetic body 20 is magnetized with four poles, and as shown in FIG. 1, the magnetizing range (for example, the effective rotation range θ1) of the N and S poles (the lower side in the drawing) of two of the four poles is used. Is set to be narrower, and the magnetization ranges of the other two north and south poles (upper side in the drawing) (for example, to the extent other than the effective rotation range θ1) are set narrow.

Next, a method of magnetizing the yoke of the ferromagnetic body 20 shown in FIG. 1 will be described with reference to FIGS. In the figure, reference numeral 21 denotes a yoke, and the yoke 21 has a ferromagnetic material 20.
2 is formed, and four holes 23, 24, 25, 26 penetrating the electric wire (coil) 15 are formed in the inner peripheral edge of the storage part 22 as shown in FIG. 2 (a). Has been done. The holes 23, 24, 25, and 26 are arranged such that the holes 24 and 25 are set at an angle of 130 ° from the hole 23 located above in FIG. The holes 26 are arranged at an angle of 180 °. θ1 is an effective rotation range, for example, θ1 = 40 °. In addition, one electric wire 15 is provided in each hole 23, 24, 25, 26.
Has been fitted around.

The hole 26 is set apart from the disk side surface of the ferromagnetic body 20 housed in the yoke 21 in the following relationship. That is, as shown in FIG. 3, adjacent magnetic poles N of the disk of ferromagnetic material 20, the distance between S and A, the center of the electric line 1 5 of the hole 26 (in magnetization by the electric wire 15
(Core: corresponding to the first magnetization center) to a line L1 connecting the center O of the ferromagnetic body 20 and a line L2 connecting the adjacent magnetic poles N and S.
And an electric wire ( first magnetization center) 15 in the hole portion 26
When the B the distance between the first magnetization center (hole portion 26
The center of the electric wire 15 ) at a position satisfying B / A = 0.5 to 1.0 (where A is smaller than the radius of the ferromagnetic body 20 ).
Is set apart from the disk peripheral surface of the ferromagnetic body 20. Further, tapered surfaces 27, 27 are formed which spread from the first magnetization center ( the center of the electric wire 15 in the hole 26) toward the disk peripheral surface (the accommodating portion 22) of the ferromagnetic body 20.

Here, B / A = 0.5 to 1.0 will be described. FIG. 4 shows the characteristics of the linearity and the distance ratio shown in FIG. 3, and in this FIG. 4, the horizontal axis shows the distance ratio (B /
A), the vertical axis represents linearity (%). By the way, since it is practically necessary for the linearity to be within 2%, it is desirable from FIG. 4 that B / A is 0.5 or more. In addition, the first magnetization center ( in the electric wire 15 in the hole 26 )
If the (heart ) is too far away from the ferromagnetic body 20 (that is, if B is too large), a large current must be passed through the wire in order to magnetize the ferromagnetic body 20.
/ A is preferably 1.0 or less. Therefore,
B / A is set to 0.5 to 1.0.

The holes 23, 24 and 25 are shown in FIG. 2 (c).
Is formed in communication with the slit in the housing section 22 as shown in, the magnetic flux due to the inserted electric wires 15 in these holes 23, 24 and 25, it as shown in FIG. 5 (a)
Then, the ferromagnetic material 20 is magnetized as shown in FIG. In FIG. 5 (a) , one of the holes 23, 24, 25
Shows the condition of the electric wire 15 at two places, and the electric wire 15 at the other two places
The state of magnetic flux and magnetic flux is omitted, but the electric wires 15 at the other two locations
Also, the magnetic flux shown in Fig. 5 (a) is generated.
The electric wire 15 inserted through these holes 23, 24, 25.
Are the second magnetization centers. On the other hand, as shown in FIG. 2A, the hole portion 26 is communicated with the housing portion 22 by the communicating portion constituted by the slit and the tapered surfaces 27, 27, and the magnetic flux from the electric wire 15 inserted into the hole portion 26 is , Fig. 5
It is generated as shown in (b) and magnetizes the ferromagnetic body 20. That is, since the first magnetization center of the electric wire 15 inserted into the hole 26 is separated from the ferromagnetic body 20, the ferromagnetic body 20
A nearly parallel magnetic field can be formed at. Therefore, there is provided a method of magnetizing a magnetic body, which has excellent linearity within a predetermined angle range and can obtain high output.

Although the above embodiment has been described with four poles, more poles may be used.

In the above-described embodiment, a ferromagnetic body 20 having a saturated magnetized disk shape and provided with four or more magnetic poles in a plan view, and the ferromagnetic body 20 is arranged on the circumferential side surface of the ferromagnetic body 20. And a magnetic detection element (Hall element 4) for detecting the magnetic force of the normal component of the ferromagnetic body 20, and as shown in FIG. 3, the distance between the adjacent magnetic poles N and S of the disk of the ferromagnetic body 20. Is A, and a line L1 connecting the first magnetization center (hole 26) to the center O of the ferromagnetic body 20 and a line L2 connecting the adjacent magnetic poles N and S.
When the distance between the intersection C of the first magnetization center (hole 26) and the first magnetization center (hole 26) is B, the first magnetization center (hole 26) is defined as B / A.
= 0.5 to 1.0 (where A is smaller than the radius of the ferromagnetic body 20), the ferromagnetic body 20 is magnetized by setting it apart from the disk peripheral surface, and , The first magnetization center (hole 2) of the magnetic pole magnetized away from the disk peripheral surface.
6) Another second magnetization center (holes 24, 25) adjacent to 6)
Is a ferromagnetic body 20 that is magnetized in contact with the circumferential surface of the disk, so that a substantially parallel magnetic field is formed in the ferromagnetic body 20. Therefore, excellent linearity and high output are obtained within a predetermined angle range. Provided is a magnetic potentiometer that can be used.

Further, in the above embodiment, the first magnetization center (hole portion 26) and the second magnetization center (hole portion 2) are used.
4, 25) , the disk-shaped ferromagnetic body 20 is housed in a yoke, and the distance between adjacent magnetic poles N and S of the disk of the ferromagnetic body 20 is set to A, and the first magnetization center pole N adjacent to (hole 26) and the line L1 connecting the centers of the ferromagnetic body 20, the intersection C between the line L2 connecting the S, first
When the distance between the magnetization center (hole portion 26) of the is B, the first
The magnetization center (hole portion 26) of B is separated from the disk side surface of the ferromagnetic body 20 at a position satisfying B / A = 0.5 to 1.0 (where A is smaller than the radius of the ferromagnetic body 20). In order to set and magnetize, the first magnetization center (hole 2
Since the tapered surfaces 27, 27 that spread from 6) toward the disk peripheral surface of the ferromagnetic body 20 are formed, it is also adjacent to the first magnetization center (hole 26) of the magnetic pole magnetized away from the disk peripheral surface. Since the other second magnetization center (holes 24, 25) is magnetized at a position close to the disk peripheral surface, a substantially parallel magnetic field can be formed in the ferromagnetic body 20, so that a predetermined angle range can be obtained. And a method of magnetizing the magnetic body 20 which is excellent in linearity and can obtain high output.

[0019]

According to the first and second aspects of the present invention, since a substantially parallel magnetic field is formed in the ferromagnetic body by magnetizing the yoke, excellent linearity and high output can be obtained within a predetermined angle range. Provided is a magnetic potentiometer that can be used. According to the third, fourth, and fifth aspects of the present invention, since a substantially parallel magnetic field is formed in the ferromagnetic body by magnetizing the yoke, it is possible to obtain excellent linearity and high output within a predetermined angle range. A method of magnetizing a magnetic body is provided.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a ferromagnetic material of an embodiment of a magnetic potentiometer according to the present invention.

2A, 2B, and 2C are a plan view and a front view showing a yoke used for magnetization, and an enlarged view of a wire insertion hole.

FIG. 3 is an explanatory diagram showing a relationship between a ferromagnetic material and an electric wire.

FIG. 4 is a diagram showing characteristics of linearity and distance ratio in FIG.

5 (a) and 5 (b) are explanatory views showing states of magnetic flux when the electric wire is magnetized in a state where the electric wire is in contact with the ferromagnetic body and a state where the electric wire is separated from the ferromagnetic body.

FIG. 6 is an explanatory diagram showing the concept of a general magnetic potentiometer.

FIG. 7 is an explanatory diagram showing the principle of the Hall element of FIG.

FIG. 8 is a circuit diagram of a general magnetic potentiometer.

FIG. 9 is an explanatory diagram showing magnetization by a core-air coil with respect to a ferromagnetic material.

10 is an explanatory diagram showing a magnetized state of a ferromagnetic body by the method of FIG.

FIG. 11 is an explanatory diagram for performing 8-pole magnetization.

[Explanation of symbols]

4 Hall element 20 Ferromagnet 24,25 holes 26 holes 27 Tapered surface A distance B distance C intersection L1 connecting line L2 connecting line N, S magnetic pole O The center of the ferromagnetic body 20

Front Page Continuation (72) Inventor Mitsumasa Inoue 1-7 Yukiya Otsuka-cho, Ota-ku, Tokyo Alps Electric Co., Ltd. (56) Reference JP-A-63-182808 (JP, A) JP-A-62-14410 (JP, A) JP-A-60-220816 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01D 5/00-5/62 G01B ⁷ /00-7/34 G01R 33 / 00-33/26

Claims (5)

(57) [Claims] 1. A disk, which is saturated and magnetized, and has a size of 4 in plan view.
A ferromagnetic body provided with magnetic poles equal to or more than a pole, and a magnetic detecting element arranged on a peripheral side surface of the ferromagnetic body for detecting a magnetic force of a normal component of the ferromagnetic body; A is the distance between adjacent magnetic poles,
Magnetize the ferromagnetic material at a position distant from the peripheral surface of the disk.
The first magnetization center before a line connecting the centers of the ferromagnetic material from which
Assuming that the distance between the intersection of a line connecting adjacent magnetic poles and the first magnetization center is B, the first magnetization center is
It is a ferromagnetic material magnetized by setting it at a position satisfying B / A = 0.5 to 1.0 (where A is smaller than the radius of the ferromagnetic material) apart from the disk peripheral surface. And magnetic potentiometer. 2. The method of claim 1 wherein the other of the second magnetization center adjacent to the first magnetization centers of magnetic poles magnetized away from the disc peripheral surface, at a position close to the disc periphery <br/> Magnetic potentiometer characterized by being a magnetized ferromagnetic material. 3. A disk-shaped ferromagnetic body is separated from the disk peripheral surface.
A first array of magnetization centers for magnetizing the ferromagnetic material at a position
Magnetize the ferromagnetic material at a position close to the disk peripheral surface
With housing the <br/> ferromagnetic in the yoke which is disposed a coil comprising a second magnetic center, the distance between adjacent magnetic poles of the disc of the ferromagnetic and A, the first magnetization When the distance between the intersection of the line connecting the center of the ferromagnetic body and the line connecting the adjacent magnetic poles and the first magnetization center is B,
The first magnetization center is set at a position satisfying B / A = 0.5 to 1.0 (where A is smaller than the radius of the ferromagnet) apart from the disk peripheral surface of the ferromagnet. A method of magnetizing a magnetic body, which comprises: 4. The magnetic body attachment according to claim 3, wherein the yoke has a tapered surface that widens from the first magnetization center toward the disk peripheral surface of the ferromagnetic body. Porcelain method. 5. The method of claim 3 wherein the other of the second magnetization center adjacent to the first magnetization center, in the disc peripheral surface
A method of magnetizing a magnetic body, characterized in that the magnets are magnetized at positions close to each other.