JP2001215236A - Magnetic rotation sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the rate of yield by making absorbable variations in surface magnetic flux of a magnet and variations in the levels of magnetic flux for driving an IC incorporated in a magnetism sensing element. SOLUTION: This magnetic rotation sensor has a structure made by combining the magnetism sensing element 3 and a magnetic-flux generating part for supplying magnetic flux to the element 3. The generating part is equipped with the hollow magnet 1 and a center yoke 2 made of a soft magnetic substance to be inserted into the hollow part of the magnet 1, and can make vertical movement by screwing the yoke 2 into a holder 6. Vertical adjustment of the yoke 2 can change the magnetic flux passing through the position of the element 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic rotation sensor for detecting a rotation state of a gear made of a soft magnetic material, for example, a rotation number and a rotation angle of a gear incorporated in a motorcycle or an automobile. In particular, the present invention relates to a magnetic rotation sensor capable of easily adjusting a magnetic flux passing therethrough at a position of a magnetically sensitive element in an IC so as to match a driving magnetic flux level of a Hall IC.

[0002]

2. Description of the Related Art Conventionally, as a rotation sensor for detecting unevenness of a gear, an IC section including a magnetically sensitive element and an integrated circuit chip and outputting an output of the magnetically sensitive element as an electric signal, and a magnetic flux for supplying a magnetic flux to the magnetically sensitive element There is a combination of generators.

The rotation sensor disclosed in Japanese Patent Application Laid-Open No. 9-49740 has a sandwich structure in which two magnets are arranged on both sides of a center yoke in the same magnetization direction in a magnetic flux generating portion. FIG. 14 shows a conventional example 1 of such a magnetic flux generating section, in which side magnets 81 are arranged on both sides of a center yoke 82. There is also a structure in which a center yoke 92 is disposed inside a hollow magnet 91 as in Conventional Example 2 of FIG. In addition, 3 is a magnetic sensitive element. Further, the center yokes 82 and 92 may be center magnets having polarities opposite to the surrounding magnets.

One of the objects of the structures shown in the prior art examples 1 and 2 is to form a closed magnetic path between both side magnets (surrounding magnets) and a center yoke, to reduce leakage magnetic flux and to efficiently use the magnets. It is in.

[0005]

By the way, there is a case where the surface magnetic flux of the magnet varies and does not coincide with the driving magnetic flux level of the Hall IC. However, in the structures of the conventional examples 1 and 2, the variation of the surface magnetic flux is corrected. There was no way to do it.

SUMMARY OF THE INVENTION In view of the above, the present invention provides a magnetic rotation sensor capable of absorbing variations in the surface magnetic flux of a magnet and variations in the drive magnetic flux level of an IC with a built-in magnetic sensing element to improve the yield. The purpose is to:

[0007] Other objects and novel features of the present invention will be clarified in embodiments described later.

[0008]

Means for Solving the Problems To achieve the above object, an invention according to claim 1 of the present application is directed to a rotation sensor in which a magnetic sensitive element and a magnetic flux generating unit for supplying a magnetic flux to the magnetic sensitive element are combined. The magnetic flux generating portion includes a hollow magnet, a center yoke inserted into the hollow portion of the hollow magnet or a center magnet opposite to the hollow magnet, and a movable mechanism is provided on the center yoke or the center magnet. It is characterized by that.

A second aspect of the present invention is characterized in that, in the first aspect, a vertical moving mechanism is provided on the center yoke or the center magnet.

According to a third aspect of the present invention, in the first aspect, a nut member having a threaded inner surface is fitted into the hollow portion of the hollow magnet, and a soft magnetic material screw is used as the center yoke. A member is screwed to the nut member.

According to a fourth aspect of the present invention, in the first aspect, the center yoke or the center magnet is provided with a rotary movement mechanism.

A fifth aspect of the present invention is characterized in that, in the first aspect, a rotation moving mechanism is provided in the holder for holding the center yoke or the center magnet.

According to a sixth aspect of the present invention, in the first, fourth or fifth aspect, a cutout is provided in a part of the center yoke or the center magnet.

According to a seventh aspect of the present invention, in the first aspect, the center yoke or the center magnet has a laminated structure.

The invention according to claim 8 of the present application provides a magnetic sensing element,
In a rotation sensor in which a magnetic flux generating unit that supplies a magnetic flux to the magnetic sensing element, the magnetic flux generating unit is a hollow magnet, and a center yoke inserted into the hollow portion of the hollow magnet or a reverse of the hollow magnet. A polar-oriented center magnet is provided, and the hollow magnet is provided with a movable mechanism.

According to a ninth aspect of the present invention, in the ninth aspect, the hollow magnet is provided with a vertical moving mechanism.

According to a tenth aspect of the present invention, in the eighth aspect, a rotation moving mechanism is provided in a magnetic flux generating portion including the hollow magnet and the center yoke or the center magnet.

The invention of claim 11 of the present application is characterized in that, in claim 8, a notch is provided in a part of the hollow magnet.

The invention of claim 12 of the present application is characterized in that, in claim 8, the hollow magnet has a laminated structure.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a magnetic rotation sensor according to the present invention will be described with reference to the drawings.

FIG. 1 and FIG. 2 show a first embodiment of a magnetic rotation sensor according to the present invention. In these figures, 1
Is a hollow magnet having a magnetic pole N on one end face and a magnetic pole S on the other end face, and a center yoke 2 of a soft magnetic material is inserted and arranged in a hollow portion of the hollow magnet. Reference numeral 3 denotes a magnetic sensitive element such as a Hall element, and 4 denotes a Hall IC incorporating the magnetic sensitive element. A screw portion 5 is formed on the center yoke 2, and the center yoke 2 is screwed to a non-magnetic adjustment holder 6 and supported by the screw portion 5. The magnetically sensitive element 3 is in direct proximity to the center yoke 2. Reference numeral 10 denotes a soft magnetic gear to be detected.

In the first embodiment, the center yoke 2 is provided with a vertical movement mechanism. That is, since the screw portion 5 of the center yoke 2 is screwed into the holder 6, by rotating the center yoke 2, the position of the lower end surface of the center yoke 2 is adjusted to adjust the hole I.
Magnetic flux applied to the magnetically sensitive element 3 in C4 (the magnetically sensitive element 3
At the position (1).

FIG. 3 shows the relationship between the passing magnetic flux at the position of the magnetic sensitive element 3 and the position of the center yoke. The center yoke position of 0.0 mm is when the lower surface of the center yoke coincides with the lower surface of the hollow magnet, and the state where the lower surface of the center yoke is retracted by 0 to 2 mm from this position is measured. It can be seen that the magnetic flux applied to the magnetic sensitive element 3 in the Hall IC 4 can be changed by adjusting the position of the lower end surface of the center yoke 2.

As described above, according to the first embodiment,
By rotating the center yoke 2 by using the support structure of the center yoke 2 as a screw structure, the position of the lower end surface of the center yoke 2 is adjusted so as to adjust the magnetic flux applied to the magnetically sensitive element 3 in the Hall IC 4 (the magnetic flux at the position of the magnetically sensitive element 3). It is possible to change the magnetic flux passing therethrough, and absorb the variation in the surface magnetic flux of the hollow magnet 1 and the variation in the driving magnetic flux level of the Hall IC 4 to improve the yield.

In the first embodiment, part or all of the center yoke 2 may be replaced with a center magnet having a direction opposite to that of the hollow magnet 1.

FIG. 4 shows a second embodiment of the present invention, in which a soft magnetic material screw member is used as a center yoke. In this case, a support 9 having a threaded inner surface as a nut member is fitted and fixed to the hollow portion of the hollow magnet 1, and a screw member 8 of a soft magnetic material is screwed into the support 9 as a center yoke. I have. By rotating the screw member 8 made of a soft magnetic material, the drive magnetic flux level of the magnetically sensitive element 3 which is close to and directly opposed to the screw member 8 can be adjusted. In other words, the magnetic flux passing through the position of the magnetically sensitive element 3 can be adjusted. The magnetic flux can be adjusted, and the variation in the surface magnetic flux of the magnet and the variation in the driving magnetic flux level of the Hall IC can be absorbed to improve the yield.

In the second embodiment, a part or all of the screw member 8 may be replaced with a center magnet whose direction is opposite to that of the hollow magnet 1, but the magnet material has difficulty in workability. In many cases, it is more practical to use a soft magnetic material for the screw member 8 as described above.

FIG. 5 shows a third embodiment of the present invention, in which a first example of a rotary mechanism for rotating a center magnet is shown. In this case, the magnetic material holder 11 is provided on the inner periphery of the hollow portion of the hollow magnet 1.
Are rotatably provided, and an adjusting magnet 12 is provided at an eccentric position in the magnetic material holder 11. In other words, the rotation magnet is provided on the holder 11 which holds the adjustment magnet 12 corresponding to the center magnet having the opposite polarity to the hollow magnet 1. By rotating the magnetic material holder 11, the rotation center of the holder is rotated. It is possible to adjust the drive magnetic flux level of the magnetically sensitive element 3 in the Hall IC disposed close to the position shifted from the axis P1.

Although the holder 11 is made of a magnetic material, the drive magnetic flux level can be adjusted even if the holder 11 is made of a non-magnetic material.
Further, it is possible to use a soft magnetic center yoke instead of the adjusting magnet 12, but in that case, it is desirable that the center yoke be approximately the same length as the holder 11.

FIG. 6 shows a fourth embodiment of the present invention, in which a second example of a rotation mechanism for a center magnet is shown. In this case, a center yoke 2 made of a soft magnetic material is fixed to the inner periphery of the hollow portion of the hollow magnet 1. A magnetic or non-magnetic cylindrical body 20 having an eccentric hollow portion is fixed to the upper surface of the hollow magnet 1. A magnetic or non-magnetic holder 21 is rotatably provided on the inner periphery of the magnetic or non-magnetic cylindrical body 20,
The holder 21 is provided with an adjusting magnet 22 at a position shifted from the holder rotation center axis P2. In other words, the configuration is such that the rotation moving mechanism is provided on the holder 21 that holds the adjustment magnet 22 corresponding to the center magnet having the opposite polarity to the hollow magnet 1.

In the fourth embodiment, the rotation center axis P2 of the holder 21 is shifted from the center of the hollow magnet 1 (the center of the hollow portion), and the position of the adjusting magnet 22 is also shifted from the rotation center axis P2. Since the holder 21 is displaced, by rotating the holder 21, the adjustment magnet 22 moves to a position completely deviated from a position overlapping the center yoke 2, and the hole arranged close to and directly opposite to the center yoke 2. I
The drive magnetic flux level of the magnetic sensing element 3 in C can be adjusted.

Although it is possible to use a soft magnetic center yoke in place of the adjusting magnet 22, the amount of change in magnetic flux is reduced.

FIG. 7 shows a fifth embodiment of the present invention, in which a notch is provided in a part of a center yoke.
In this case, a center yoke 30 made of a soft magnetic material, which is cut out in a tapered shape, is rotatably provided on the inner periphery of the hollow portion of the hollow magnet 1. That is, the center yoke 30 is provided with a rotary movement mechanism and the center yoke 30 has a cutout 31
Is provided.

In the fifth embodiment, the notch 3
By rotating the center yoke 30 formed at the end facing the magnetic sensing element 3, the drive magnetic flux level of the magnetic sensing element 3 of the Hall IC provided at a position shifted from the rotation center axis P 3 can be adjusted. .

In the fifth embodiment, the center yoke 30 may be replaced by a hollow magnet and a center magnet whose polarity is opposite to that of the hollow magnet.

FIG. 8 shows a sixth embodiment of the present invention, showing another example in which a notch is provided in a part of the center yoke. In this case, a semi-cylindrical center magnet (or yoke) 35 is rotatably provided on the inner periphery of the hollow portion of the hollow magnet 1, and the semi-cylindrical non-magnetic material 36 is provided on the center magnet 35.
(Resin) is fixed to form the columnar body 37 as a whole. In other words, it corresponds to a structure in which the center magnet 35 is provided with a rotation moving mechanism and a part of the center magnet 35 is provided with a notch.

In the sixth embodiment, the cylindrical body 3
By rotating 7, the driving magnetic flux level of the magnetically sensitive element 3 in the Hall IC provided at a position shifted from the rotation center axis P4 can be adjusted.

FIG. 9 shows a seventh embodiment of the present invention.
In this case, a flat columnar center magnet (or soft magnetic center yoke) 40 is provided in a multi-layered manner on the inner periphery of the hollow portion of the hollow magnet 1. By changing the number of stacked center magnets 40 (for example, by fixing the uppermost center magnet 40 and sequentially stacking it below), the inside of the Hall IC that is close to and directly opposed to the lowermost center magnet 40 Of the magnetic sensitive element 3 can be adjusted.

Each of the center magnets 40 has a structure in which the center magnet 40 and the hollow magnet are stacked in the opposite direction.

FIG. 10 shows an eighth embodiment of the present invention, which shows a mechanism for moving a hollow magnet up and down. In this case, a threaded soft magnetic center yoke 45 is provided on the inner periphery of the hollow portion of the hollow magnet 1, and a rotation adjusting portion 46 is formed on the upper surface of the hollow magnet 1. And screw around it.

In the eighth embodiment, the hollow magnet 1 can be moved up and down with respect to the center yoke 45 by rotating the rotation adjusting portion 46 with respect to the center yoke 45 fixedly held. In addition, it is possible to adjust the drive magnetic flux level of the magnetically sensitive element 3 in the Hall IC that is close to and directly opposed to the center yoke 45.

Although part or all of the center yoke 45 may be replaced with a center magnet having a direction opposite to that of the hollow magnet 1, the magnet material often has difficulty in workability.
It is more practical to use the center yoke 45 made of a soft magnetic material as described above.

FIG. 11 shows a ninth embodiment of the present invention, which shows a rotating and moving mechanism of a magnetic flux generating section comprising a hollow magnet and a center yoke. In this case, a hollow magnet 1 is provided at an eccentric position inside the cylindrical non-magnetic holder 50, and a center yoke 2 is provided on the inner periphery of the hollow portion of the hollow magnet 1.
Is fixed. The columnar non-magnetic holder 50 is rotatable, and corresponds to a structure in which a rotation moving mechanism is provided in a magnetic flux generation unit including the hollow magnet 1 and the center yoke 2.

In the ninth embodiment, the holder 50
, The driving magnetic flux level of the magnetically sensitive element 3 in the Hall IC provided at a position shifted from the rotation center axis P5 can be adjusted.

In the ninth embodiment, it is also possible to use a hollow magnet and a center magnet whose direction is opposite to that of the hollow magnet, instead of the center yoke 2.

FIG. 12 shows a tenth embodiment of the present invention, in which a cutout is provided in a part of a hollow magnet.
In this case, the center yoke 2 is provided on the inner periphery of the hollow portion of the hollow magnet 60 having the notch 61, and the hollow magnet 60 is rotatable around the center yoke 2 as a center of rotation. By rotating the hollow magnet 60, the rotation center axis P6
The drive magnetic flux level of the magnetically sensitive element 3 in the Hall IC provided at a position shifted from the position can be adjusted.

In the tenth embodiment, instead of the center yoke 2, it is possible to use a center magnet whose direction is opposite to that of the hollow magnet.

FIG. 13 shows an eleventh embodiment of the present invention, in which a hollow magnet has a laminated structure. In this case, the center yoke 2 is provided on the inner periphery of the hollow portion of the laminated structure of the hollow flat columnar magnet 70. This is equivalent to providing a hollow magnet with a laminated structure and providing a vertical moving mechanism for the hollow magnet (the magnet 70 is moved up and down by changing the number of stacked magnets 70).

In the eleventh embodiment, the driving magnetic flux level of the magnetic sensing element 3 in the Hall IC can be adjusted by changing the number of laminations of the hollow flat columnar magnets 70.

In the eleventh embodiment, instead of the center yoke 2, it is possible to use a center magnet whose direction is opposite to that of the hollow magnet.

In each of the embodiments, it is apparent that the center yoke or the center magnet may be a combined structure of the center yoke and the center magnet.

Although the embodiments of the present invention have been described above, it is obvious to those skilled in the art that the present invention is not limited to the embodiments and various modifications and changes can be made within the scope of the claims. There will be.

[0053]

As described above, according to the magnetic rotation sensor according to the present invention, the center yoke or the center yoke or the center is formed by combining the magnetically sensitive element and the magnetic flux generating section for supplying the magnetic flux to the magnetically sensitive element. Since the movable mechanism is provided on the magnet or the movable mechanism is provided on the hollow magnet, it is possible to change the magnetic flux applied to the magnetically sensitive element (the magnetic flux passing through at the position of the magnetically sensitive element). I with built-in surface magnetic flux variation and magnetic sensitive element
The yield can be improved by absorbing the variation in the drive magnetic flux level of C.

[Brief description of the drawings]

FIG. 1 is a sectional view of an overall configuration including a center yoke moving mechanism according to a first embodiment of a magnetic rotation sensor according to the present invention.

FIG. 2 is a perspective view of a main part configuration according to the first embodiment of the present invention.

FIG. 3 is a graph showing characteristic evaluation results when a center yoke is moved.

FIG. 4 is a perspective view of a second embodiment of the present invention, showing a configuration in which a screw member made of a soft magnetic material is used as a center yoke.

FIG. 5 is a perspective view showing a third example of a rotation mechanism of a center magnet according to a third embodiment of the present invention.

FIG. 6 is a perspective view illustrating a second example of a rotation mechanism of a center magnet according to a fourth embodiment of the present invention.

FIG. 7 is a perspective view showing a fifth embodiment of the present invention, in which a notch is provided in a part of a center yoke.

FIG. 8 is a sixth embodiment of the present invention, and is a perspective view showing a configuration in which a cutout is provided in a part of a center yoke.

FIG. 9 is a perspective view of a seventh embodiment of the present invention, showing a configuration in which a center magnet (or a center yoke) has a laminated structure.

FIG. 10 is an eighth embodiment of the present invention, and is a perspective view showing a vertical moving mechanism of a hollow magnet.

FIG. 11 is a perspective view showing a ninth embodiment of the present invention, showing a rotating and moving mechanism of a magnetic flux generating unit including a hollow magnet and a center yoke.

FIG. 12 is a perspective view of a tenth embodiment of the present invention, showing a configuration in which a cutout is provided in a part of a hollow magnet.

FIG. 13 is a perspective view showing an eleventh embodiment of the present invention, showing a configuration in which a hollow magnet has a laminated structure.

FIG. 14 is a perspective view showing an example of a magnetic flux generation unit in a conventional magnetic rotation sensor.

FIG. 15 is a perspective view showing another example of the magnetic flux generating unit in the conventional magnetic rotation sensor.

[Explanation of symbols]

 1,60,91 Hollow magnet 2,30,45,82,92 Center yoke 3 Magnetic sensitive element 4 Hall IC 5 Screw part 6,11,21,50 Holder 7 Side magnet 8 Screw member 9 Support post 10 Gear 12,22 Adjusting magnet 20, 37 Cylindrical body 31, 61 Notch 35, 40 Center magnet 36 Non-magnetic material 46 Rotation adjusting part 70 Hollow flat cylindrical magnet 81 Side magnet

Claims (12)

[Claims] 1. A rotation sensor in which a magnetically sensitive element is combined with a magnetic flux generating part for supplying a magnetic flux to the magnetically sensitive element, wherein the magnetic flux generating part is inserted into a hollow magnet and a hollow part of the hollow magnet. A magnetic rotation sensor comprising: a center yoke or a hollow magnet and a center magnet having an opposite polarity, and a movable mechanism provided on the center yoke or the center magnet. 2. The magnetic rotation sensor according to claim 1, wherein a vertical movement mechanism is provided on the center yoke or the center magnet. 3. A method according to claim 1, wherein a nut member having a threaded inner surface is fitted into a hollow portion of the hollow magnet, and a screw member made of a soft magnetic material is screwed to the nut member as the center yoke. The magnetic rotation sensor according to claim 1, wherein: 4. The magnetic rotation sensor according to claim 1, wherein a rotation moving mechanism is provided on the center yoke or the center magnet. 5. The magnetic rotation sensor according to claim 1, wherein a rotation moving mechanism is provided on the holder holding the center yoke or the center magnet. 6. The magnetic rotation sensor according to claim 1, wherein a notch is provided in a part of the center yoke or the center magnet. 7. The magnetic rotation sensor according to claim 1, wherein the center yoke or the center magnet has a laminated structure. 8. A rotation sensor in which a magnetically sensitive element is combined with a magnetic flux generating part for supplying a magnetic flux to the magnetically sensitive element, wherein the magnetic flux generating part is inserted into a hollow magnet and a hollow part of the hollow magnet. A magnetic rotation sensor comprising a center yoke or a center magnet having a direction opposite to that of the hollow magnet, and a movable mechanism provided in the hollow magnet. 9. The magnetic rotation sensor according to claim 8, wherein a vertical moving mechanism is provided on the hollow magnet. 10. The magnetic rotation sensor according to claim 8, wherein a rotation moving mechanism is provided in a magnetic flux generation unit including the hollow magnet and the center yoke or the center magnet. 11. The magnetic rotation sensor according to claim 8, wherein a cutout portion is provided in a part of the hollow magnet. 12. The magnetic rotation sensor according to claim 8, wherein the hollow magnet has a laminated structure.