JP2001133210A - Mon-contact type position sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly accurate sensor for reducing the linear error of output from a magnetic sensitive element accompanying the rotation of a magnetic generation body and simplifying the constitution of a magnetic circuit suitable for use in an automobile, in a non-contact type position sensor for detecting a rotary displacement position and a linear displacement position. SOLUTION: The magnetic generation body 1 arranged on a rotary shaft 8 rotated in response to a rotating operation from the outside and magnetized in a vertical direction to the rotary shaft 8 is surrounded by a first yoke 2a and a second yoke 2b through an air gap 7, in a direction orthogonal to the rotary shaft 8 and housed rotatably around the inner periphery of the yoke. The magnetic sensitive element 4 is arranged in a first gap 3a opposedly formed under the first yoke 2a and the second yoke 2b parallelly formed on a first plane passing through the rotary shaft 8, and a magnetic body 5 for constituting a magnetic bypass means under a second gap 6 smaller than the first gap 3a is arranged near the first gap 3a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact position sensor for detecting a rotational displacement position and a linear displacement position in a non-contact manner.

[0002]

2. Description of the Related Art Conventionally, for example, a rotary position sensor used as a throttle opening sensor of a vehicle-mounted internal combustion engine, a linear position sensor used as a valve stroke sensor of the engine, and the like, determine a rotation angle and a linear movement amount of an object to be detected. Sliding resistors were often used as sensors for detection. This sliding type resistor has many problems in terms of accuracy as a sensor, such as fluctuation of output characteristics and generation of noise due to friction and fouling of a sliding portion.

Therefore, at present, for example, a detection signal corresponding to the direction of a magnetic field received from the outside, such as an accelerator pedal operation amount detection device described in Japanese Patent Application Laid-Open No. 8-49575, which is the first prior art, is disclosed. A so-called non-contact type position sensor for detecting the rotation angle of the object to be detected in a non-contact manner by using a generated magneto-electric conversion element and a pair of arc-shaped magnets arranged to face each other with the magneto-electric conversion element interposed therebetween. Is being used. Incidentally, in such a non-contact type position sensor, there is no sliding portion in the sensor element itself, and therefore, there is no fear that the output characteristics fluctuate or noise is generated due to friction or contamination.

[0004] In addition, a magnetic position and speed sensor having a Hall element described in Japanese Patent Publication No. 9210722, which is a second prior art, is known. The sensor comprises a magnet surrounding a rotating shaft and a stator located on the opposite side of the magnet. The stator is fixed to the casing by a fixture, and a hall sonde and an exciting winding are arranged facing each other in a recess of the stator.

A third prior art, Japanese Patent No. 516, is disclosed.
The angular position sensor described in Japanese Patent No. 4668, which has reduced sensitivity to a change in shaft position, has a rotating magnet and two magnetic pole pieces opposed to each other on a surface orthogonal to the rotation axis of the rotating magnet. The Hall element is arranged in an end gap formed by opposing the magnetic pole piece and the rotating magnet, and the magnet is arranged between the other end or the opposing magnetic pole piece extending to the other end.

A fourth prior art, Japanese Patent Laid-Open Publication No. 9-2
The turning angle detection device described in Japanese Patent No. 43311 is composed of three or more magnetic pole pieces surrounding a magnetic pole direction of a rotating magnet. The same number of air gaps as the magnetic pole pieces are arranged around the magnet, and the individual magnetic poles are arranged. It has a magnetic detection gap extending from one piece, and processes signals of two Hall elements arranged in the detection gap.

[0007]

However, in the above-mentioned first prior art magnetic circuit, the sensor output is the amount of rotational movement (rotation) by which a constant magnetic field from a pair of opposed arc-shaped magnets surrounding the magneto-electric conversion element rotates. (Rotational direction), the output signal is sinusoidal, and when used for a sensor with a large amount of rotational movement, such as a throttle opening sensor,
A digital processing circuit for correcting the output signal to a straight line is required.

In the second prior art sensor, since the magnet used is a magnet which is radially cross-magnetized, its material is limited, and the temperature characteristics of the magnet pose a problem when used in an automobile. Therefore, improvements are needed for use in automobiles.

In the third prior art sensor, the effect of the gap between the rotating magnet and the pole piece is less susceptible to the displacement of the rotating magnet, and the output signal from the Hall element is the first signal. As in the prior art sensor, means for correcting the sinusoidal output to a straight line in the detection angle range is required.

In the fourth prior art sensor,
A signal obtained by detecting a rotational angle position using three or more magnetic pole pieces and two Hall elements is processed by an absolute value adder, an adder, and a divider, and the detected signal is processed. It is composed of complicated magnetic circuit components and a signal processing circuit for obtaining a signal.

According to the present invention, for example, in detecting a rotational movement amount required by a throttle opening degree sensor, a linear error of a sensor output is smaller than 1%, which is suitable for use in an automobile, has high accuracy, and has a magnetic circuit. It is an object of the present invention to provide a non-contact type position sensor having a simple configuration.

[0012]

In order to solve the above-mentioned problems, a non-contact type position sensor according to the present invention is arranged on a rotating shaft which rotates in response to a rotating operation from the outside, and is provided with respect to the rotating shaft. A first magnet and a first yoke that surrounds the magnetized magnet and the magnetic pole of the magnet and that are formed parallel to a first plane passing through the rotation axis and opposed by at least two first gaps; And a second yoke, a magnetic sensing element disposed in the first gap and responsive to a change in magnetic flux density in the first gap with rotation of the magnetic generator, and A magnetic bypass having a cross-sectional area smaller than a cross-sectional area of the first yoke and the second yoke, including a magnetic body disposed near the first gap, and formed under a second gap smaller than the first gap; Means, wherein the magnetic generator is provided with the rotating shaft. Interlinking it in the presence of an air gap that the rotatable inside the first yoke and the second yoke.

With this configuration, when the magnetic generator rotates, a magnetic flux having a magnetic flux density higher than the magnetic flux density passing through the first gap in which the magnetic sensing element is disposed passes through the magnetic bypass means including the second gap. The magnetic flux of the first gap, which changes in a sinusoidal manner due to the rotation of the magnetic generator, is bypassed through the second gap by the change characteristic of the magnetic permeability relative to the magnetizing force of the magnetic material forming the magnetic bypass means. As a result, for example, in the rotational movement region of the throttle opening sensor, the linearity of the change in magnetic flux passing through the magnetic sensing element in the first gap is improved, which is suitable for use in an automobile, has high accuracy, and has a magnetic circuit configuration. However, a simple non-contact type position sensor can be obtained.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to a magnetic generating device which is disposed on a rotating shaft which rotates in response to a rotating operation from the outside, and is magnetized in a direction perpendicular to the rotating shaft. Body and at least two first magnets surrounding the magnetic poles of the magnetic generator and formed parallel to a first plane passing through the rotation axis.
A first yoke and a second yoke facing each other under the gap;
A magnetic sensing element disposed in the first gap and responsive to a change in magnetic flux density in the first gap as the magnetic generator rotates, the first yoke and the second yoke forming the first gap; The cross-sectional area is smaller than the cross-sectional area of the yoke.
A magnetic body disposed in the vicinity of the air gap, and magnetic bypass means formed under a second air gap smaller than the first air gap, wherein the magnetic generator is provided in the presence of an air gap orthogonal to the rotation axis. And a non-contact type position sensor rotatable inside the first yoke and the second yoke.

In this sensor, when the magnetic generator rotates, a magnetic flux having a magnetic flux density higher than the magnetic flux density passing through the first gap in which the magnetic sensing element is disposed passes through the magnetic bypass means including the second gap. In addition, the magnetic flux of the first gap that rises in a sinusoidal shape due to the rotation of the magnetic generator is bypassed through the second gap by the change characteristic of the magnetic permeability relative to the magnetizing force of the magnetic body that forms the magnetic bypass unit. As a result, an error in output linearity due to a change in magnetic flux passing through the magnetic sensing element in the first gap in the rotational movement region of the sensor is improved.

According to a second aspect of the present invention, in the first aspect of the present invention, the first yoke and the second yoke are non-contact type position sensors made of a semi-annular magnetic material, The end faces of the magnetic material face each other to form the first gap, and the magnetic bypass means including the second gap in the vicinity of the first gap is formed, so that the yoke magnetic path length can be minimized and the magnetic loss can be reduced. A small sensor with a small size can be realized.

According to a third aspect of the present invention, there is provided a magnetic generator arranged on a rotating shaft which rotates in response to a rotating operation from the outside, and magnetized in a direction perpendicular to the rotating shaft; And at least three first gaps that are parallel to a first plane passing through the rotation axis and are plane-symmetric with respect to the first plane, but are formed differently in the axial direction of the rotation axis. A first yoke and a second yoke facing each other, a magnetic sensing element disposed in the first gap, and sensitive to a magnetic flux density in the first gap with rotation of the magnetic generator; A magnetic body disposed in the vicinity of the first gap and having a smaller cross-sectional area than the first yoke and the second yoke forming the first yoke and formed under a second gap smaller than the first gap Provided magnetic bypass means, wherein the magnetic generator is Is a non-contact type position sensor is rotatable inside the first yoke and the second yoke in the presence of the axial air gap direction and the rotation axis orthogonal to the rotation axis. In the sensor having this configuration, the first gap, the magnetic bypass unit, and the magnetic sensing element can be installed at a position that is not easily affected by the displacement of the magnetic generator in the axial radial direction. Can be realized.

According to a fourth aspect of the present invention, there is provided a first yoke having a first yoke piece and a second yoke piece, a third yoke piece having an end face opposed to the first yoke piece, and A second yoke having a fourth yoke piece whose side face is opposed to the second yoke piece; and a second yoke positioned in a space defined by the first yoke and the second yoke, and rotated in response to a rotation operation from the outside. A magnetic generator arranged on the rotating shaft and magnetized in a direction perpendicular to the rotating shaft; and a continuous unit between the first yoke and the second yoke formed parallel to a first plane passing through the rotating shaft. A magnetic sensing element disposed in one first gap and responsive to a change in magnetic flux in the first gap due to the rotation of the magnetic generator; and a cross-sectional area smaller than the yoke forming the first gap. It has a cross-sectional area and includes a magnetic body disposed near the first gap. , A magnetic bypass means formed under the first gap smaller than the first gap, said first
The yoke and the second yoke have a key-shaped cross section perpendicular to the first plane passing through the rotation axis and on a second plane passing through the rotation axis. A non-contact type position sensor capable of rotating the inner circumferences of the first yoke and the second yoke in the presence of an air gap in a direction orthogonal to the rotation axis.

In the sensor having this configuration, the first gap formed by the first yoke piece and the third yoke piece face-to-face is one face, so that the first gap having excellent dimensional accuracy can be realized. . In addition, the first gap, the magnetic bypass unit and the magnetic sensing element can be installed at a position that is not easily affected by the displacement of the magnetic generator in the direction of the shaft radial direction. As a result, a high-performance sensor with less assembly variation can be provided. realizable.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the first yoke and the second yoke are each formed of a semi-cylindrical yoke having a bottom, so that the magnetic flux collecting ability is further improved. can do. And since a 1st space | gap can be comprised in a plane perpendicular | vertical to the plane parallel to a rotation axis,
There is an advantage that the space for installing the magnetic bypass unit and the magnetic sensing element is not restricted.

According to a sixth aspect of the present invention, in the invention according to the fourth aspect, the first yoke and the second yoke are each formed of a semi-cylindrical yoke having a bottom, and the first yoke and the second yoke are provided on the bottom of the yoke. Since a circular third gap centered on the rotation axis larger than one gap is added, the amount of change in magnetic flux across the first gap can be further increased. As a result, a sensor having high sensitivity to the amount of rotational movement can be realized.

According to a seventh aspect of the present invention, in the sixth aspect of the present invention, the diameter of the third gap is enlarged to the same diameter as the outer shape of the magnetic generator.
Further, a non-contact type position sensor having high sensitivity to the amount of rotational movement can be realized.

[0023] The invention described in claim 8 is the first or third invention.
4. The non-contact type position sensor according to any one of items 4, wherein the magnetic permeability of the magnetic body of the magnetic bypass unit has a positive coefficient with respect to a change in magnetic flux density due to rotation of the shaft and is non-linear. By controlling the magnetic flux in the first air gap so that the magnetic flux change in the first air gap due to the rotational movement of the magnetic generator is linearly corrected by the magnetic bypass unit, the first air gap is controlled.
The amount of change in magnetic flux across the gap can be increased. As a result, a sensor having high sensitivity to the rotational movement amount can be realized, and a signal having excellent linearity can be obtained from the magnetic sensing element.

According to the ninth aspect of the present invention, there is provided an image processing apparatus comprising:
5. The invention according to any one of items 4, wherein at least two or more magnetic bypass units are provided for the first gap,
The magnetic sensing element is disposed in the first gap formed between the magnetic bypass means. According to this configuration, the magnetic flux distribution in the first gap in which the magnetic sensing element is arranged can be made uniform. As a result, it is possible to realize a sensor that is hardly affected by the displacement of the position of the magnetic sensing element.

The invention according to claim 10 is the first invention,
In the invention described in any one of 3 and 4, the magnetic bypass means provided near the first gap is constituted by one magnetic plate having at least two magnetic paths bridging the first gap, A magnetic sensing element is disposed in the first gap existing between the magnetic paths, and the magnetic plate is integrated with the first yoke and the second yoke by mechanical coupling means. The first gap in which the magnetic sensing element is disposed is determined by the magnetic plate, and as a result, the yoke can be easily positioned and the characteristics can be stabilized.

[0026] The invention described in claim 11 is based on claim 1,
In the invention according to any one of the third and fourth aspects, the material of the magnetic body of the magnetic bypass unit is the same as a member constituting the yoke, and is opposed to the first gap by the first gap. A part of the first yoke and the second yoke is extended on the first yoke surface and the second yoke surface to form a projection serving as magnetic bypass means, and a second gap is formed at the tip of the projection. The magnetic circuit can be formed by arranging the magnetic circuits so as to face each other. Therefore, desired characteristics can be obtained with a minimum combination of processed parts.

According to a twelfth aspect of the present invention,
In the invention according to any one of the third and fourth aspects, the material of the magnetic body of the magnetic bypass unit is made of a different material from a member constituting the yoke. Due to the magnetic loss of the two yokes, the magnetic flux passing through the first gap in which the magnetic sensing element is provided may not change uniformly with respect to the magnetomotive force due to the rotational movement of the magnetic generator. In this case, the linearity of the magnetic flux change passing through the magnetic sensing element is improved by selecting a magnetic bypass unit having a non-linear magnetic permeability different from the yoke material suitable for the magnetic flux change characteristic of the first air gap caused by the material difference of the yoke. Can be.

[0028] The invention described in claim 13 is based on claim 1,
In the invention described in any one of Items 3 and 4, the magnetic material forming the magnetic bypass means is a soft magnetic material made of an electromagnetic steel plate, a rolled steel for structure, or a steel for structure. According to this material, the magnetic permeability is linear in a region where the magnetomotive force is small, and has a positive non-linear characteristic in a region where the magnetomotive force is large. Accordingly, since the magnetic flux is bypassed through the magnetic bypass means in accordance with the change in the magnetomotive force of the first gap due to the rotation of the magnetic generator, the magnetic flux of the first gap curved sinusoidally with the rotation of the magnetic generator. The change can be corrected to a characteristic with good linearity.

[0029] The invention described in claim 14 is based on claim 1,
In the invention described in any one of (3) and (4), the member forming the second gap is made of a non-magnetic material, and the surface of the first yoke, the second yoke, and the magnetic material of the magnetic bypass unit is formed of a non-magnetic material. The first gap is formed by mechanically integrating the first yoke, the second yoke, and the magnetic bypass means. According to this configuration, the magnetic flux of the magnetic body can be limited by the high magnetic resistance of the nonmagnetic body with respect to the magnetic field change in the first gap due to the rotation of the magnetic generator. Therefore, by changing the thickness of the non-magnetic material, it is possible to adjust the operating region of the magnetic permeability of the magnetic material of the magnetic bypass means, and to change the yoke material and the structure of the magnetic circuit and the magnetic material of the magnetic bypass means. It is possible to improve the error in the linearity of the generated sensor output.

According to a fifteenth aspect of the present invention, in the invention of the fourteenth aspect, the nonmagnetic member constituting the second gap is a plating film or a coating film. According to this configuration, the setting of the magnetic permeability of the magnetic bypass unit including the second gap can be easily determined by the plating film thickness or the coating film thickness, and the effect of preventing rust of the magnetic bypass unit and the yoke is added. A high-performance sensor with little change over time can be realized.

According to a sixteenth aspect of the present invention, in the invention according to the fourteenth aspect, the non-magnetic member constituting the second gap is formed of a film tape. The first yoke, the second yoke, and the magnetic body of the magnetic bypass unit are bonded and fixed to any surface.
According to this configuration, it is possible to adjust the magnetic permeability of the magnetic bypass unit including the second gap by changing the thickness of the tape. As a result, it is possible to easily adjust an error in the linearity of the sensor output caused by the variation of the magnetic circuit.

The thickness of the second gap formed between the first yoke and the second yoke and the magnetic body of the magnetic bypass means may be the first gap. Needless to say, it is smaller than the interval. Since the magnetic resistance of the second air gap is smaller than the magnetic resistance of the first air gap, the magnetic flux density of the second air gap can be made larger than the magnetic flux density of the first air gap. As a result, by using magnetic bypass means shorter than the length of the side where the first yoke and the second yoke forming the first gap face each other,
A desired amount of magnetic flux for correcting a linearity error can be bypassed. As a result, the first yoke and the second
The linearity error of the sensor output can be corrected by the magnetic bypass unit smaller than the shape of the yoke. And the first
Since the magnetic bypass means is formed of a magnetic material having a smaller cross-sectional area than the opposed cross-sectional area of the first yoke and the second yoke forming the air gap, the magnetic flux density of the magnetic material forming the magnetic bypass means is reduced by the first yoke The magnetic flux density of the magnetic yoke can be made higher than the magnetic flux density of the second yoke, and the change in the magnetic permeability of the magnetic bypass means with respect to the rotational movement amount of the magnetic generator can be increased.
As a result, it is possible to improve the linearity of the sensor output accompanying the rotational movement amount of the magnetic generator while reducing the decrease in the magnetic flux density of the first air gap (the decrease in the sensitivity of the sensor) caused by the magnetic bypass unit. Further, in a yoke material having a large residual magnetic flux, the residual magnetic field generated in the first gap is bypassed by the magnetic bypass means, so that the hysteresis of the sensor output caused by the reciprocating rotation of the magnetic generator can be reduced.

According to a seventeenth aspect of the present invention, in the invention of the fourteenth aspect, the magnetic bypass means including a second gap made of a nonmagnetic material is mechanically connected to the first yoke and the second yoke. The means for integrating is one of thermosetting resin, thermoplastic resin, non-magnetic eyelet, heat welding, and ultrasonic welding. According to this configuration, the magnetic bypass means including the second gap can be firmly fixed. Thus, stable characteristics with little change over time can be obtained.

[0034] The invention described in claim 18 is based on claim 1,
In the invention according to any one of the third and fourth aspects, a magnetic bypass unit is disposed and fixed in a recess provided in the first yoke and the second yoke. According to this configuration, the second yoke, the second yoke, and the magnetic bypass unit can be easily arranged by forming the second gap in advance and fitting the magnetic bypass unit into the concave portion, and also positioning the magnetic bypass unit. Can be performed more accurately, so that the sensor characteristics can be stabilized. And since there is no need to use complicated fixing means,
The number of assembly steps can be reduced, and an inexpensive sensor can be obtained.

[0035] The invention described in claim 19 is based on claim 1,
In the invention described in any one of (3) and (4), the first gap is formed by a nonmagnetic spacer that mechanically integrates the first yoke and the second yoke. The dimensions are determined by the spacers. As a result, the positioning of the first yoke and the second yoke is facilitated, and the characteristics can be stabilized.

According to the twentieth aspect of the present invention,
In the invention according to any one of (3) and (4), since the magnetically sensitive element is held by a filler inserted into the first gap between the first yoke and the second yoke, the magnetically sensitive element The position can be completely fixed, and a sensor that is robust against mechanical vibration can be realized.

[0037] The invention described in claim 21 is based on claim 1,
In the invention as set forth in any one of (3) and (4), since at least two or more of the magnetic sensing elements are disposed in the first gap, a desired output is required when two or more signals are required from the sensor. Can be obtained.

[0038] The invention described in claim 22 is based on claim 1,
The magnetic sensing element according to any one of the third and fourth aspects, wherein the magnetic sensing element is a Hall element, and a voltage signal proportional to a change in magnetic flux density of the first gap due to the rotational movement of the magnetic generator; Since an output voltage corresponding to the change in magnetism can be obtained, this voltage signal can be amplified to obtain a desired sensor signal.

According to the twenty-third aspect of the present invention,
In the invention described in any one of 3 and 4, since the magnetic generator is formed of a disk-shaped magnet, a sensor output accompanying rotation of the magnetic generator when there is no magnetic bypass means has a more sine wave. Output characteristics are close and smooth.
It is possible to easily correct the output with a small linearity error by the smooth change characteristic of the magnetic permeability of the magnetic bypass means including the air gap, and as a result, a sensor with excellent linearity can be realized. Further, the first yoke and the second yoke surround the magnetic generator so that an air gap dimension orthogonal to the rotation axis becomes uniform, and further, the first yoke and the second yoke surround the magnetic generator in the axial direction of the first yoke and the second yoke. By providing the air gap, it is possible to realize a high-performance sensor that is hardly affected by the displacement of the magnetic generator in the axial direction and the radial direction of the shaft.

The invention described in claim 24 is the first invention,
In the invention described in any one of 3 and 4, since the magnetic generator is formed of a ring-shaped magnet, a connecting means of a rotating shaft made of a soft magnetic material or a non-magnetic material is provided in a hollow portion of the ring-shaped magnet. A desired variation can be configured in a bearing structure in which the magnetic generator can be easily rotated and the magnetic generator is directly rotated by receiving the rotation shaft of the throttle valve.

According to the twenty-fifth aspect of the present invention,
The invention according to any one of Items 3 and 4, wherein the magnetic generator is a magnet having two arc-shaped magnetic pole surfaces. According to this shape, since it has a surface parallel to the outer shape of the magnet, the surface can be fixed and magnetized at the time of magnetization, so that the magnetization direction is stable, and as a result, at the rotation reference position, A sensor with less variation in sensor output can be realized.

According to a twenty-sixth aspect of the present invention, in the first aspect of the present invention, since the magnetic generator has a positioning hole coaxial with the rotating shaft, it is magnetized. In this case, since the magnetization can be performed based on this hole, the magnetization direction can be stabilized, and the positioning hole can be used to easily arrange the magnetic generator on the rotating shaft. As a result, a high-performance sensor with little variation in sensor output at the rotation reference position can be realized.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

(Embodiment 1) FIG. 1A is a top view for explaining the principle of a first embodiment of a non-contact type position sensor according to the present invention, and FIG. 1B is a front view thereof. FIG.
1 (a) and 1 (b), reference numeral 1 denotes a magnetic generator disposed on a rotating shaft 8 which rotates in response to a rotating operation from the outside;
The first and second yokes 2a and 2b surround the magnetic poles of the magnetic generator 1 and are opposed to a plane passing through the center 9 of the rotating shaft, and 3a and 3b are formed between the yokes 2a and 2b. The first gap 4 is a magnetic sensing element, which responds to a change in magnetic flux in the first gap 3a due to the rotation of the magnetic generator 1.
a is the sensing surface of the magnetic sensing element 4, 5 is the first gap 3a,
A magnetic body disposed in the vicinity of the first gap 3a having a smaller cross-sectional area than the first yoke or the second yoke forming the first yoke 3b; The second gap 56 is provided in the second gap 6.
And a magnetic bypass means 7 composed of the magnetic body 5 and an air gap formed between the first yoke, the second yoke and the magnetic generator 1 in a direction perpendicular to the axis of the rotating shaft 8.
Here, reference numeral 10 denotes a magnetization direction of the magnetic generator 1, which is perpendicular to the axis of the rotation axis 8. φ1 is the first gap 3
a, 3b and the magnetic flux passing through the sensing surface 4a of the magnetic sensing element 4.

In the first embodiment, the first yoke 2
a, the second yoke 2b is made of a soft magnetic material,
a and 3b so as to face each other. The magnetic body 5 is also made of a soft magnetic body, and the second gap provided between the magnetic body 5 and the first and second yokes is set smaller than the distance between the first gaps 3a or 3b. . The magnetic generator 1 is made of a rectangular parallelepiped SmCo permanent magnet whose cross section perpendicular to the rotation axis 8 is square or rectangular, and is uniaxially oriented in a direction 10 perpendicular to the rotation axis 8. The magnetization is oriented. The magnetic sensing element 4 is formed of a Hall element, and the magnetic flux φ1 passing through the first gap 3a is fixed in the first gap 3a with a filler or the like so as to be perpendicular to the sensing surface 4a of the Hall element. I have. The rotating shaft 8 is preferably made of a non-magnetic material such as stainless steel so as not to affect the magnetic circuit.

First, the operating principle of the non-contact type position sensor of the present invention will be described with reference to FIGS. FIG. 2A is a top view of a non-contact type position sensor schematically showing the flow of a magnetic flux φ when the magnetic generator 1 rotates, and FIG.
It is a figure which shows the output voltage from the Hall element 4 which is a magnetic sensing element of (a). 2, the same components as those in FIG. 1 are denoted by the same reference numerals, detailed description thereof will be omitted, and only different portions will be described.

In FIG. 2A, θ is the magnetic sensing element 4
Is the angle at which the magnetization direction of the magnetic generator 1 is rotationally moved from the sensing surface 4a, φ is the magnetic flux passing through the first gaps 3a, 3b and the sensing surface 4a of the Hall element 4 formed at equal intervals, and L is the magnetic generator 1 The length h of the magnetic pole indicates the width of the magnetic pole of the magnetic generator 1, and is different from FIG. 1 in that a non-contact rotary position sensor 91 without a magnetic bypass unit is provided.

The operation of the thus constructed non-contact type position sensor will be described. FIG. 2A shows that the magnetic generator 1 moves from the position where the magnetization direction of the magnetic sensing surface 4a and the magnetization direction of the magnetic
The distribution of the magnetic flux φ when rotating is shown. Then, at this position, the N and S pole faces of the magnetic generator 1 and the first
On the surface facing the yoke and the second yoke, a part of the magnetic generator 1 is magnetically short-circuited (the hatched portion in FIG. 2A) via the air gap 7, the first yoke, and the second yoke. Then, a magnetic flux φ generated by the remaining magnetomotive force of the magnetic generator 1 passes through the first gaps 3a and 3b and the magnetic sensing element 4 housed therein, and a voltage proportional to the magnetic flux φ from the magnetic sensing element 4 is generated. Is output. Therefore, when the magnetic resistance of the first yoke 2a and the second yoke 2b is constant, the voltage output from the magnetic sensing element 4 is substantially proportional to the rotation angle θ of the magnetic generator. Due to the relationship of the magnetization direction 10 of the rotating magnetic generator 1 with respect to 2, the output voltage of the Hall element 4 becomes approximately a sine wave. This relationship is shown in FIG. FIG. 2B shows the relationship between the rotation angle θ of the magnetic generator 1 and the output voltage of the Hall element 4. FIG.
FIGS. 2C, 2D and 2E are schematic diagrams showing the rotation of the magnetic generator 1. FIG. First, when the sensing surface 4a of the magnetic sensing element 4 and the magnetization direction 10 are parallel as shown in FIG. 2C, both magnetic poles of the magnetic generator 1 are short-circuited to each other via the first yoke and the second yoke. , The magnetic flux φ applied to the sensing surface 4a becomes zero. This state is defined as θ = 0. Thus, when the magnetic generator 1 rotates and θ increases or decreases, the amount and direction of the magnetic flux flowing through the first gaps 3a and 3b change, and the magnetic flux φ applied to the sensing surface 4a also changes to change the magnetic sensing element 4 Output also fluctuates.

Here, about ± 45 in FIGS. 2C to 2E.
When measuring the angle in the range of deg, the shape of the magnetic generator 1 may be a rectangular parallelepiped magnet in which the width h of the magnetic pole is equal to the length L of the magnetic pole, and the output of the rectangular magnet is represented by a solid line in FIG. the V _1. Further, it can be inferred from the above description that h and L of the magnetic generator 1 when measuring ± 45 deg or more preferably have a relationship of h> L. However, the output of these magnetic circuit configurations has a measurement error with respect to the ideal output of a straight line that is approximately sinusoidal and proportional to the rotation angle θ.

Next, the operation when the magnetic bypass means 56 is arranged near the first gap 3a shown in FIG. 1 and under the second gap 6 will be described with reference to FIGS. FIG. 3 schematically shows the magnetic circuit of FIG. 1 as an equivalent circuit, and FIG. 4 shows a change in magnetic flux passing through the magnetic sensing element with respect to the rotation angle of the magnetic generator in the magnetic circuit. FIG. 5 is a magnetic characteristic diagram of the magnetic material constituting the magnetic bypass unit 56.

In FIG. 3, M is a magnetomotive force exerted by the magnetic generator 1, g1 and g2 are magnetic resistances corresponding to an air gap between the magnetic generator 1 and the first yoke 2a and the second yoke 2b, r1 and r2 Are the first yoke 2a and the second yoke 2
b, R1 is the magnetic resistance of the first gap 3a, 4 is a Hall element disposed in the first gap 3a, φ is the magnetic flux passing through the first yoke 2a and the second yoke 2b, and φ1 is the Hall element. A magnetic flux passing through 4, R2 is a magnetic resistance corresponding to the second gap 6, μ is a magnetic permeability of the magnetic body 5, and 56 is a magnetic bypass unit including the magnetic resistance R2 and the magnetic permeability μ. The magnetic bypass unit 56 has a configuration in which the magnetic circuit 91a of the non-contact type position sensor without the magnetic bypass unit is connected in parallel to the magnetic resistance R1 including the magnetic sensing element 4 disposed in the first gap. ing.

In the operation of this magnetic circuit configuration, a sinusoidal magnetic field accompanying the rotation of the magnetic generator 1 is applied to the first gap 3a and the magnetic bypass means 56 by the same operation as in FIG. . By this magnetic field, the first gap 3a
Passes through the magnetic flux φ1 limited by the magnetic resistance R1,
The magnetic resistance R2 of the second gap 6 and the magnetic flux φ2 limited by the magnetic permeability μ of the magnetic body 5 also pass through the magnetic bypass means 56. The magnetic flux φ2 changes depending on the magnitude of the magnetic field applied to the magnetic material and the magnetic permeability characteristics determined by the magnetic flux density in the magnetic material. Therefore, the magnetic body 5 of the magnetic bypass unit 56 is made of a soft magnetic material, and is positive and linear under the condition where the applied magnetic field is small as shown in FIG. The magnetic flux φ2 with a small linear error is obtained by bypassing the magnetic flux φ2 with the magnetic permeability peculiar to the magnetic substance and subtracting φ2 from the magnetic flux φ due to the sine-wave applied magnetic field accompanying the rotation of the magnetic generator.
1 is obtained. Therefore, as shown in FIG.
The change in the sinusoidal magnetic flux φ due to the rotation of the magnetic generator 1
The magnetic flux φ1 having a small linear error can be obtained, and the linearity of the magnetic flux φ1 passing through the first gaps 3a and 3b including the magnetic sensing element 4 is improved. Is improved.

By making the cross-sectional area of the magnetic body 5 traversed by the first plane passing through the rotation axis 9 smaller than the cross-sectional area of the yoke forming the first gaps 3a and 3b, during rotation of the magnetic generator 1, The magnetic flux density of the magnetic body 5 of the magnetic bypass means is always made larger than the magnetic flux density passing through the first gap and the magnetic flux density of the yoke, and the effect of changing the magnetic permeability of the magnetic body can be efficiently obtained under the condition that the bypass magnetic flux φ2 is small. It has a configuration. Further, the area in contact with the first yoke and the second yoke is reduced, the bypass magnetic flux φ2 is reduced, the sensitivity of the sensor is prevented from lowering, and the mounting space for the magnetic sensing element can be secured.

As is apparent from the above operation, the magnetic flux φ1 has a value obtained by subtracting φ2 from the magnetic flux φ without the magnetic bypass means. Therefore, the magnetic sensitivity of the sensor is reduced as shown by φ1 in FIG. 4 by providing the magnetic bypass unit. However, this problem is solved by amplifying the output signal of the magnetic sensing element by a circuit using an operational amplifier or the like. Is done.

In the first embodiment of the present invention, only an example in which a Hall element is used as the magnetically sensitive element 4 has been described, but the present invention is not necessarily limited to this. In the first embodiment of the present invention, Sm is used as the magnetic generator 1.
The case where a Co permanent magnet is used has been described, but the present invention is not necessarily limited to this. Further, in the first embodiment of the present invention, the arrangement position of the magnetic bypass unit 56 is described on the A plane orthogonal to the rotation axis 9 in FIG. 1, but the same effect can be obtained on the B plane parallel to the rotation axis. Can be. Further, in the first embodiment of the present invention, the arrangement of the magnetic bypass unit 56 and the magnetic sensing element 4 has been described as being the same gap, but is not necessarily limited to this.

(Embodiment 2) FIG. 6 is a top view for explaining a non-contact type position sensor according to a second embodiment of the present invention. 6, the same components as those in FIG. 1 are denoted by the same reference numerals, detailed description thereof will be omitted, and only different components will be described. In FIG. 6, the difference from the first embodiment is that the two yokes are composed of the first yoke 22a and the second yoke 22b with two semi-annular magnets. The principle of operation of the second embodiment is basically the same as that described in the first embodiment, and a detailed description thereof will be omitted.

In this configuration, since the two yokes surrounding the magnetic generator 1 are substantially annular with the rotation axis 9 as the center, the magnetic path length of the yoke of the magnetic circuit is shortest and the magnetic loss is small. A small sensor can be realized.

(Embodiment 3) FIG. 7 is a top view for explaining a third embodiment of the non-contact type position sensor of the present invention, and FIG. 8 is another application obtained by modifying the embodiment of FIG. It is a figure showing an example. 7 and 8, the same components as those in FIG. 1 are denoted by the same reference numerals, detailed description thereof will be omitted, and only different components will be described. In addition, the operation principle of the third embodiment is basically the same as that described in the first embodiment, and a detailed description thereof will be omitted.

In FIG. 7, reference numeral 32a denotes a first yoke;
b is a second yoke, 12a is an extension yoke piece in which a part of the first yoke 32a extends to a surface direction perpendicular to the rotation axis 9,
Reference numeral 12b denotes an extended yoke piece in which a part of the second yoke 32b extends in a plane direction perpendicular to the rotation axis 9, and 3c denotes a gap formed at the tip of the first yoke piece 12a and the second yoke piece 12b. The first gap is formed in the same region (first plane passing through the rotation axis 9) as the first gaps 3a and 3b provided in the surface opposing portions of the first yoke 32a and the second yoke 32b. I have. That is, in the third embodiment (FIG. 7), the first yoke 32a including the extension yoke piece 12a and the second yoke 32b including the extension yoke piece 12b are formed on the first plane passing through the rotation axis 9 of the magnetic generator 1. The first yoke 32a and the second yoke 32b are opposed to each other and have three first air gaps formed in parallel with the first plane. Then, the magnetic bypass means 5 including the second gap
The magnetic sensing element 4 and the magnetic sensing element 4 are arranged in a first gap 3 c away from the magnetic generator 1 at a position parallel to the rotation axis 9 and generate magnetism in the presence of an air gap 7 orthogonal to the rotation axis 9. The body 1 is configured to rotate inside the yoke 2.

FIG. 8A is a top view of a non-contact type position sensor which is another application example of the present embodiment.
(B) is this front view. In the third embodiment (FIG. 8), reference numeral 84 denotes a first yoke surrounding the magnetic generator 1;
a is an extension yoke piece configured so that a part of the first yoke 84 extends parallel to a plane orthogonal to the rotation axis 9 to cover the magnetic generator 1, and 85 is a first yoke piece surrounding the magnetic generator 1. 2
The yoke 85a is an extended yoke piece configured so that a part of the first yoke 85 extends in parallel to a plane perpendicular to the rotation axis 9 to cover the magnetic generator 1. 3d is the two extended yoke pieces. 84a and 85a are opposing air gaps, and are first air gaps 3a, parallel to a first plane passing through the rotation axis 9.
In the region 3b, a first gap is formed. Magnetic bypass means 56 including second gap and magnetic sensing element 4
Is disposed in a gap 3d in which the two extension yoke pieces 84a and 85a are opposed to each other, and an air gap 7 in the axial direction of the rotation axis 9 and an air gap 7a in a direction orthogonal to the rotation axis 9 are provided. Is arranged so that the magnetic generator 1 rotates inside the yoke 2 in the presence of. Here, FIG.
The difference from the case is that the gap 3d constituting the first gap 3d is extended in the axial direction.

In the third embodiment, the magnetic sensing element 4
And the magnetic bypass means 56 at a position separated from the magnetic generator 1,
Alternatively, since it can be arranged at a position that is hardly affected by the magnetization direction of the magnetic generator 1, a magnetic field change due to a positional shift of the magnetic generator 1 in the radial direction of the shaft due to mechanical tolerance and durable wear to be considered in the configuration of the sensor. It is possible to realize a high-precision sensor which is hardly affected by the influence.

In the third embodiment of the present invention, the arrangement of the magnetic bypass means 56 and the magnetic sensing element 4 has been described as being the same space, but the present invention is not necessarily limited to this.

(Embodiment 4) FIG. 9A is a top view for explaining a non-contact type position sensor according to a fourth embodiment of the present invention, and FIG. 9B is a side view thereof. is there. In FIG. 9, reference numeral 62 denotes a first yoke having a first yoke piece 62a and a second yoke piece 62b, and 63 denotes a third yoke piece 63a whose end face is opposed to the first yoke piece 62a and the second yoke piece. Fourth yoke piece 6 whose side face faces yoke piece 62b
A second yoke 1b having a magnet 3b is magnetized in a direction perpendicular to the axis of rotation 9 and is provided with a magnetic generator disposed on a rotary shaft 8 which rotates in response to an external rotation operation. A magnetic sensing element that senses a change in magnetic flux in the first air gap 64 due to rotation, the first yoke 62 and the second yoke 63
Continuous air gap between the first yoke piece 62a or the third yoke piece 63a and the magnetic generator 1, and 70 the second yoke piece 62b or the fourth yoke piece 62b.
Air gap between the yoke piece 63b and the magnetic generator 1;
Is a second gap between the first yoke piece 62a and the third yoke piece 63a, and 5 is a magnetic gap disposed between the first yoke piece 62a and the third yoke piece 63a via the second gap 6. It is a body and constitutes the magnetic bypass means 56. In the fourth embodiment, the first yoke 62 and the second yoke 63 are made of a soft magnetic material, and are arranged to face each other under the first gap 64. The cross-sectional area of the magnetic body 5 traversed by the first gap 64 is set to be smaller than the cross-sectional area of the first yoke piece 62a or the third yoke piece 63a opposed via the first gap 64, and The magnetic generator 1 is configured to rotate inside the first yoke 62 and the second yoke 63 in the presence of the air gap 71 in the axial direction and the air gap 70 in the direction perpendicular to the rotation axis 9. I have.

Since the principle of operation of the fourth embodiment is basically the same as that described in the first embodiment, a detailed description will be omitted.

According to the configuration of the magnetic circuit in the fourth embodiment, the first yoke piece 62a and the third yoke piece 63a
Since the surfaces face each other via the continuous first gaps 64, the first gaps 64 with high dimensional accuracy can be easily realized. Therefore, the magnetic distribution of the first gap 64 becomes uniform, and the magnetic sensing element 4 disposed in the first gap 64 is hardly affected by the displacement. In addition, since the magnetic sensing element 4 is disposed in the closed magnetic circuit, the magnetic sensing element 4 is displaced in the axial direction and the radial direction of the axis, that is, when the air gap 70 or the air gap 71 fluctuates. Very unlikely to be affected.

As described above, with the configuration of the fourth embodiment, the magnetic sensing element 4 is hardly affected by the displacement of the mounting position of the magnetic sensing element 4, the displacement of the magnetic generator 1 in the axial direction and the radial direction of the shaft, and the magnetic circuit And a high-performance sensor with a simple sensor output linearity error can be realized.

(Embodiment 5) FIG. 10A is a top view for explaining a non-contact position sensor according to a fifth embodiment of the present invention, and FIG. 10B is a side view thereof. is there. 10, the same components as those in FIG. 9 are denoted by the same reference numerals, detailed description thereof will be omitted, and only different portions will be described. In FIG. 10, the first yoke 62 and the second yoke 63 are configured by semi-cylindrical yoke pieces having a bottom portion, and are arranged so as to face each other under the first gap 64. In addition, the magnetic yoke 1 includes the first yoke 62 and the second yoke 6 under the air gap 70 and the air gap 71.
It is surrounded by three.

The operation principle of the fifth embodiment is basically the same as that described in the first embodiment, and a detailed description thereof will be omitted.

The fifth embodiment is different from the fourth embodiment in that a semi-cylindrical yoke piece having a bottom is used. In this configuration, the magnetic generator 1
Is a closed magnetic circuit that is surrounded by a semi-cylindrical yoke with a bottom in the radial direction, so that the magnetism collecting ability of the yoke is improved as compared with the fourth embodiment, and the first gap 64 is formed by rotation of the magnetic generator 1. The change in magnetic flux can be increased. As a result, a non-contact type position sensor with higher sensitivity than in the fourth embodiment can be realized.

(Embodiment 6) FIG. 11A is a top view for explaining a non-contact type position sensor according to a sixth embodiment of the present invention, and FIG. ) Is a top view in which another form is modified. 11, the same components as those in FIG. 10 are denoted by the same reference numerals, detailed description thereof will be omitted, and only different portions will be described.

The sixth embodiment is different from the fifth embodiment in that the bottom of semi-cylindrical yokes 62 and 63 having bottoms opposed to each other under the first gap 64 with the rotation axis 9 as the center. Gap 72 having a diameter larger than the gap of the first gap 64
Is added to the magnetic circuit. According to this configuration, a gap 72 having a large distance (large magnetic resistance) is interposed on a part of the continuous first gap 64,
The amount of change in magnetic flux in which the magnetic sensing element 4 is arranged can be increased. As a result, a sensor with higher sensitivity than in the fifth embodiment can be realized. FIG. 11B shows a configuration in which the diameter of the gap 73 is further enlarged to the diameter inscribed in the magnetic generator 1 as compared with FIG. 11A. According to this configuration, a sensor with higher sensitivity can be obtained. Further, by fixing a bearing (not shown) for positioning the rotation to the gaps 72 and 73, a structure in which the rotation shaft 8 connected to the magnetic generator 1 is passed is also possible, and the structure of the sensor can be designed. The applicability in doing so expands. In the sixth embodiment of the present invention, the magnetic body 5 constituting the magnetic bypass means 56 is arranged on the side surface of the yoke, but is not necessarily limited to this surface.

(Embodiment 7) FIG. 12 is a top view for explaining a non-contact position sensor according to a seventh embodiment of the present invention. 12, the same components as those in FIG. 10 are denoted by the same reference numerals, detailed description thereof will be omitted, and only different components will be described.

The seventh embodiment is different from the fifth embodiment in that two magnetic bypass means 56 and 76 composed of the second gap 6 and the magnetic body 5 are arranged in the first gap 64. It is. According to this configuration, the magnetic bypass unit 5
6 and 76 can be distributed to the two magnetic bypass units 56 and 76, so that the first air gap 6 adjacent to the magnetic bypass units 56 and 76 where the magnetic sensing element 4 is arranged is arranged.
4a can be reduced, and the magnetic field distribution of the first gap 64a sandwiched between the magnetic bypass means 56 and 76 can be made uniform.
The detection sensitivity error does not occur even if the magnetic sensing element 4 is arranged to the vicinity of. As a result, it is possible to provide a sensor that is not affected by the displacement of the magnetic sensing element 4.

(Eighth Embodiment) FIG. 13 is a top view for explaining an eighth embodiment of the non-contact type position sensor of the present invention. In FIG. 13, the same components as those in FIG. 10 are denoted by the same reference numerals, detailed description thereof will be omitted, and only different components will be described.

The eighth embodiment differs from FIG. 10 in that the magnetic bypass means is constituted by a single magnetic plate 86 having two magnetic paths by bridging the first gap 64. The magnetic sensing element 4 is arranged on the first yoke 62 and the first yoke 62 and the second yoke 63 are integrated by a mechanical connecting means using the magnetic plate 86. According to this configuration, the first gap 64 between the first yoke 62 and the second yoke 63 is determined by the magnetic plate 86, and the sensor characteristics can be stabilized.

(Embodiment 9) FIG. 14A is a top view for explaining a ninth embodiment of the non-contact type position sensor of the present invention, and FIG. 14B is a side view thereof. is there. 14, the same components as those in FIG. 10 are denoted by the same reference numerals, detailed description thereof will be omitted, and only different portions will be described.

The ninth embodiment differs from FIG. 10 in that the first yoke 6
2 and a part of the second yoke 63 are extended to form protrusions 37 and 38.
And the second gaps 37a and 38b are formed at the tips of the extended protrusions 37 and 38.

In the ninth embodiment, the present inventor has shown that the magnetic body forming the magnetic bypass means is preferably made of a magnetic steel sheet, a rolled structural steel sheet, or a structural steel sheet.
When the second gap was formed with air or a magnetic permeability close to air, the result was obtained that the gap of the second gap having a ratio of 0.2 or less to the gap of the first gap was optimal. This is due to the following operation according to the present invention, which will be described below with reference to FIG. FIG. 15 is a magnetization characteristic diagram showing the relationship between the magnetic flux density B and the magnetic permeability μ with respect to the magnetizing force when a magnetizing force is applied to the material of the magnetic body of the magnetic bypass unit. As shown in FIG. 15, the change in the magnetic flux density B and the magnetic permeability μ with respect to the magnetizing force is linear in the region where the magnetomotive force is small, and the change in the magnetic flux density B and the magnetic permeability μ is linear in the region where the magnetomotive force is large. Has a characteristic that the change in the magnetic permeability changes non-linearly, and the magnetic force of the first gap, which changes in a sinusoidal shape due to the rotation of the magnetic generator, is magnetically bypassed with this magnetization characteristic, so that the linear error is small. You can get the output. And, as mentioned above,
Since the first gap is set to be larger than the second gap, the first gap is set.
The magnetic circuit has a magnetic flux density of the yoke and the second yoke which is much smaller than that of the magnetic bypass means, and operates in a linear region of magnetic permeability, and passes a magnetic flux proportional to a magnetic force change accompanying rotation of the magnetic generator. Works as

According to this configuration, the magnetic material having the magnetic bypass effect can be provided under the same material of the first yoke 62, the second yoke 63 and the magnetic bypass means without separately preparing a magnetic material of the magnetic bypass means. It can be a circuit, and a sensor with a small linear error can be realized. According to this configuration, the magnetic circuit can be simply configured with a minimum combination of the number of processed components, and thus cost reduction can be achieved.

The operating region of the magnetic body of the magnetic bypass means has a magnetic flux density that has a margin with respect to the saturation magnetic flux density of the magnetic body in the range of the magnetomotive force H shown in FIG. 15 due to the action of the second gap. Insensitive to temperature.

Further, if an electromagnetic steel sheet is used for the magnetic body,
Since the magnetomotive force and the magnetic permeability curve are various, materials suitable for the magnetic circuit can be easily selected.

In the ninth embodiment of the present invention, a semi-cylindrical yoke having a bottom has been described. However, the present invention is not limited to this. Are also included in the present invention.

In order to adapt these magnetic circuit components to the use environment of an automobile or the like, rust prevention treatment is required. Therefore, Embodiments 1 to 9 of the present invention
In the non-contact type position sensor, the surfaces of the first yoke, the second yoke, and the magnetic bypass unit are made of a plating film or a coating film made of a non-magnetic material, and a rust-proofing film thickness suitable for the second gap is formed. And are arranged in close contact with each other. And the second
When the gap between the gaps is insufficient in the surface treatment film thickness, the second gap may be formed of a film-like tape such as polyimide having excellent heat resistance in combination with the rust prevention treatment,
As a means for correcting a linear error of the sensor output caused by a variation in mechanical components and mechanical tolerances of the magnetic circuit, by changing the operating area of the magnetic permeability of the magnetic material of the magnetic bypass means by changing the thickness of the tape, Errors can also be corrected. The second gap may be formed of a nonmagnetic plate.

In order to fix the magnetic body as the magnetic bypass means to the yoke, the magnetic body is firmly adhered and fixed with a thermosetting resin, a thermoplastic resin, or a non-magnetic eyelet.
In the case where the second gap is a non-magnetic plating film, the second gap may be adhered by heat welding, ultrasonic welding, or an adhesive.

In the description of the ninth embodiment, only the example of the one-band type using one magnetic sensing element 4 is described. However, by preparing a plurality of these magnetic sensing elements 4, Detecting an abnormal state and performing self-diagnosis by one output or an output combining both,
It is also possible to improve various characteristics by using a combined output of the two.

(Embodiment 10) FIG. 16 is a perspective view of a first yoke for explaining a non-contact position sensor according to a tenth embodiment of the present invention. In the tenth embodiment,
10 is different from FIG. 10 in that a concave portion 43 or 44 is provided on the surface A or the surface B of the first yoke 62.
The configuration is such that the magnetic bypass means 46 or 47 is fitted with the magnetic bypass means 46. According to this configuration, the magnetic bypass unit 46 or 47 can be fixed to the first yoke 62 without using complicated fixing units. In the tenth embodiment, a configuration in which the concave portion is provided in the first yoke has been described, but a configuration in which the concave portion is provided in both the first yoke and the second yoke may be used.

As shown in FIG. 17, a non-magnetic spacer 45 is provided in the first gap, and the first yoke and the second
By mechanically integrating the yokes, the size of the first gap is determined by the thickness of the spacer. As a result, the positioning of the bottomed semi-cylindrical first and second yoke pieces is facilitated, and the characteristics are improved. Can be stabilized.

(Embodiment 11) FIGS. 18 to 20 are views showing the shape of a magnetic generator for explaining an eleventh embodiment of the non-contact type position sensor of the present invention. FIG.
8 to 20, the same components as those in FIG. 6 are denoted by the same reference numerals, detailed description thereof will be omitted, and only different components will be described.

In the eleventh embodiment, the first embodiment
10 is that the shape of the magnetic generator is substantially circular in the direction orthogonal to the rotation axis 9.

In FIG. 18, reference numeral 51 denotes a magnet as a magnet, and 52 denotes an air gap surrounding the magnet 51 with a first yoke 22a and a second yoke 22b. In this configuration, the magnet 51 has a disk shape with the rotation axis 9 as the center, and the sensor output without the magnetic bypass means 56 has a more sinusoidal and smoother curve than the rectangular parallelepiped magnet. In addition, it is easy to correct the linear error by the magnetic bypass unit. Since the air gap 52 is provided at equal intervals around the magnet 51 in the radial direction, and the magnet 51 is surrounded by the first yoke 22a and the second yoke 22b, even if the magnet 51 shifts in the radial direction, G in FIG.
The change of 1 and g2 acts to cancel each other, and the total reluctance of the closed magnetic circuit does not change. Therefore, a non-contact type position sensor which is hardly affected by the displacement of the magnet in the radial direction and has excellent linearity can be realized.

FIG. 19 (a) shows a ring-shaped magnet 53, and FIG. 19 (b) is a perspective view of the ring-shaped magnet provided with bearing means.

According to this structure, the same effect as that of the disk-shaped magnet can be obtained. In addition, as shown in FIG. 19B, a bearing means 55 is provided in the hollow portion 54 of the ring-shaped magnet 53, and The bearing groove 55a for receiving the shaft 48 connected to the throttle valve in the bearing means 55 can be easily formed, and the range of application of the shaft connection structure for rotating the magnet is widened.

FIG. 20 shows an oval-shaped magnet generator. 57 is an oval-shaped magnet having two arc-shaped magnetized surfaces.
50 is a hole provided in the magnet 57, 57a and 57b are magnetic pole surfaces of the magnet 57, 57c and 57d are planes parallel to the magnetization direction, and 58 is a magnetizing yoke for magnetizing the magnet 57. The shape of the magnet 57 has two flat surfaces 57c and 57d parallel to the magnetization direction, and the magnetic pole surfaces 57a and 57b are formed in an arc shape. In this case as well, the characteristic that the linear error can be easily corrected is obtained, and the magnetizing yoke 5
In the case of magnetizing at 8, the two planes 57c and 57d can be fixed and can be magnetized based on this plane.
Therefore, the magnetization direction with respect to the magnet shape is stable, and the variation in sensor output when the position of the first gap formed by the first and second yokes and the position based on the shape of the magnet are matched. Can be reduced.

Further, by using the hole 50 provided in the magnet 57 as a positioning hole coaxial with the rotation axis 9, the magnetic generator can be easily positioned on the rotation axis. In addition, variations in sensor output can be reduced. According to the eleventh embodiment, since a closed magnetic circuit having a small magnetic resistance surrounding the magnet is formed, irreversible demagnetization due to a thermal load does not occur, and the step of heat-wiring the magnet can be omitted. it can.

In the eleventh embodiment, an example has been described in which one permanent magnet consisting of a pair of magnetic poles is used as the magnetic generator. However, the pair of arc-shaped magnets described in the first conventional example is replaced with the pair of arc-shaped magnets. A configuration in which the components are opposed to each other may be used.

[0096]

As described above, according to the present invention, the linear error of the output of the magnetic sensing element due to the rotation of the magnetic generator is 1% or less, which is suitable for use in automobiles, has high accuracy, and has a magnetic circuit. A non-contact type position sensor having a simple configuration can be obtained.

[Brief description of the drawings]

FIG. 1A is a top view showing a first embodiment of a non-contact type position sensor of the present invention. FIG. 1B is a front view of the sensor.

2A is a top view showing the operation principle of the sensor; FIG. 2B is an output characteristic diagram showing the operation principle of the sensor; FIGS. 2C, 2D and 2E are schematic diagrams showing the operation principle of the sensor;

FIG. 3 is an equivalent circuit diagram of the sensor.

FIG. 4 is a diagram showing a change in magnetic flux of the sensor.

FIG. 5 is a magnetic characteristic diagram of a magnetic body as a magnetic bypass unit used in the sensor.

FIG. 6 is a top view showing a second embodiment of the non-contact type position sensor of the present invention.

FIG. 7 is a top view showing a non-contact position sensor according to a third embodiment of the present invention;

FIG. 8A is a top view showing a modification of the third embodiment of the non-contact type position sensor of the present invention; FIG.

9A is a top view showing a non-contact position sensor according to a fourth embodiment of the present invention, and FIG.

10A is a top view showing a non-contact position sensor according to a fifth embodiment of the present invention. FIG.

FIG. 11A is a top view showing a sixth embodiment of the non-contact position sensor of the present invention. FIG. 11B is a top view showing a modification of the sixth embodiment of the non-contact position sensor of the present invention. Figure

FIG. 12 is a top view showing a non-contact position sensor according to a seventh embodiment of the present invention;

FIG. 13 is a top view showing a non-contact position sensor according to an eighth embodiment of the present invention;

14A is a top view showing a ninth embodiment of the non-contact position sensor of the present invention. FIG.

FIG. 15 is a magnetization characteristic diagram illustrating an operation region of a magnetic material used in the sensor.

FIG. 16 is a perspective view showing a non-contact position sensor according to a tenth embodiment of the present invention.

FIG. 17 is a perspective view showing another embodiment of the sensor.

FIG. 18 is a top view showing a non-contact position sensor according to an eleventh embodiment of the present invention.

FIG. 19A is a top view showing the shape of another magnet of the same sensor. FIG. 19B is a perspective view showing an application of the magnet.

FIG. 20 is a top view showing the shape of another magnet of the sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic generator 2a 1st yoke 2b 2nd yoke 3a, 3b 1st gap 4 Magnetic sensing element 4a Sensing surface 5 Magnetic body 6 2nd gap 7 Air gap 7a Air gap 8 Rotation axis 9 Rotation axis 10 Magnetization direction 12a 12b Extension yoke piece 22a First yoke 22b Second yoke 32a First yoke 32b Second yoke 37 Projection 37a Second gap 38 Projection 38b Second gap 43 Depression 44 Recess 45 Spacer 46 Magnetic body 47 Magnetic body 48 Shaft 50 Hole 53 Magnetic generator 54 Hollow part 55 Bearing means 55a Bearing groove 56 Magnetic bypass means 57 Magnetic generator 58 Magnetized yoke 62 First yoke 62a First yoke piece 62b Second yoke piece 63 Second yoke 63a Third yoke Piece 63b fourth yoke piece 64 first gap 70 air gap 71 d Gap 72 third gap 73 third gap 76 the magnetic body 84a, 85a yoke pieces 86 magnetic plates 91a magnetic circuit

Claims (26)

[Claims] 1. A magnetic generator arranged on a rotary shaft that rotates in response to a rotation operation from the outside, and magnetized in a direction perpendicular to the rotary shaft, and a magnetic pole surrounding the magnetic generator, A first yoke and a second yoke opposed by at least two first gaps formed parallel to a first plane passing through the axis;
A yoke, a magnetic sensing element disposed in the first gap for sensing a change in magnetic flux density in the first gap with rotation of the magnetic generator, and a first sensing element forming the first gap.
A magnetic bypass unit having a cross-sectional area smaller than a cross-sectional area of the yoke and the second yoke, including a magnetic body disposed near the first gap, and formed under a second gap smaller than the first gap; A non-contact position sensor, wherein the magnetic generator is rotatable inside the first yoke and the second yoke in the presence of an air gap orthogonal to the rotation axis. 2. The non-contact position sensor according to claim 1, wherein the first yoke and the second yoke are made of a semi-annular magnetic body. 3. A magnetic generator that is arranged on a rotating shaft that rotates in response to a rotating operation from the outside, and that is magnetized in a direction perpendicular to the rotating shaft; A first yoke which is parallel to the first plane passing therethrough, and which is symmetrical with respect to the first plane, but faces at least three first gaps formed so as to be different in the axial direction of the rotation axis; A second yoke, a magnetic sensing element disposed in the first gap, and responsive to a change in magnetic flux density in the first gap with rotation of the magnetic generator, and a second element forming the first gap. Magnetic bypass means having a cross-sectional area smaller than a cross-sectional area of the first yoke and the second yoke, including a magnetic body disposed near the first gap, and formed under a second gap smaller than the first gap. Wherein the magnetic generator is orthogonal to the rotation axis. A non-contact position sensor rotatable inside the first yoke and the second yoke in the presence of an air gap in the direction of rotation and in the axial direction of the rotation shaft. 4. A first yoke having a first yoke piece and a second yoke piece, a third yoke piece having an end face facing the first yoke piece, and a side face facing the second yoke piece. A second yoke having a fourth yoke piece, and a rotation shaft disposed in a space defined by the first yoke and the second yoke and rotated in response to a rotation operation from the outside, and A magnetic generator magnetized perpendicular to the axis and disposed in a single continuous first gap between the first and second yokes formed parallel to a first plane passing through the axis of rotation; A magnetic sensing element responsive to a change in magnetic flux in the first air gap due to the rotation of the magnetic generator, and a cross-sectional area smaller than a cross-sectional area of the first yoke or the second yoke forming the first air gap. A magnetic material disposed near the first gap; Magnetic bypass means formed under a second gap smaller than the first gap, wherein the first yoke and the second yoke are perpendicular to the first plane passing through the rotation axis, and are connected to the rotation axis. The first yoke and the second yoke in the presence of an air gap in the axial direction of the rotation axis and in the direction orthogonal to the rotation axis. Non-contact type position sensor that is rotatable on the inner circumference of the device. 5. The non-contact position sensor according to claim 4, wherein the first yoke and the second yoke are semi-cylindrical yokes having a bottom. 6. The first yoke and the second yoke are semi-cylindrical yokes having a bottom, and a circular third gap is added to the bottom of the yoke and is larger than the first gap and centered on the rotation axis. The non-contact type position sensor according to claim 4, wherein 7. The non-contact position sensor according to claim 6, wherein the diameter of the third gap is increased to the outer shape of the magnetic generator. 8. The magnetic permeability of the magnetic body as the magnetic bypass means is a positive coefficient with respect to the strength of the magnetic field applied to the magnetic body as the magnetic bypass means accompanying the rotational movement of the magnetic generator. 5. The non-contact position sensor according to claim 1, which is non-linear. 9. The method according to claim 1, wherein at least two or more magnetic bypass means are provided for the first gap, and a magnetic sensing element is provided in the first gap formed between the magnetic bypass means. 5. The non-contact position sensor according to any one of 4. 10. A magnetic body as magnetic bypass means disposed in the vicinity of the first air gap is constituted by a single magnetic body plate having at least two magnetic paths bridging the first air gap. A magnetic sensing element is disposed in the first gap existing between the roads, and the magnetic plate is integrated with the first yoke and the second yoke by mechanical connection means.
The non-contact type position sensor according to any one of the above. 11. The non-contact type position sensor according to claim 1, wherein a material of a magnetic body as said magnetic bypass means is the same as a member constituting said yoke. 12. The non-contact type position sensor according to claim 1, wherein a material of a magnetic body as said magnetic bypass means is different from a member constituting said yoke. 13. The non-contact type position according to claim 1, wherein the magnetic material forming the magnetic bypass means is a soft magnetic material made of a magnetic steel sheet, a rolled steel for a structure, or a steel for a structure. Sensor. 14. A member forming the second gap is a non-magnetic material, and forms the second gap between the surfaces of the first yoke and the second yoke and the surface of the magnetic material as the magnetic bypass means. 5. The non-contact position sensor according to claim 1, wherein the first yoke, the second yoke, and the magnetic bypass unit are mechanically integrated. 15. The non-contact position sensor according to claim 14, wherein the non-magnetic member constituting the second gap is formed of a plating film or a coating film. 16. The non-contact position sensor according to claim 14, wherein the non-magnetic member forming the second gap is formed of a film tape. 17. A means for mechanically integrating said magnetic bypass means including a second gap made of a non-magnetic material into said first yoke and said second yoke, comprises a thermosetting resin, an injection molding resin, a non-magnetic The non-contact position sensor according to claim 14, wherein the non-contact position sensor is any one of eyelet, thermal welding, and ultrasonic welding. 18. The non-contact position sensor according to claim 1, wherein a concave portion is provided in each of the first and second yokes, and the magnetic bypass unit is fixed in the concave portion. 19. The non-contact device according to claim 1, wherein the first gap is formed by a nonmagnetic spacer that mechanically integrates the first yoke and the second yoke. Type position sensor. 20. The magnetic head according to claim 1, wherein a filler is inserted into the first gap between the first yoke and the second yoke, and the magnetic sensitive element is held by the filler. A non-contact type position sensor according to the above. 21. The non-contact position sensor according to claim 1, wherein at least two or more of said magnetically sensitive elements are disposed in said first gap. 22. The non-contact type position sensor according to claim 1, wherein the magnetic sensing element is a Hall element. 23. The non-contact type position sensor according to claim 1, wherein the magnetic generator comprises a disk-shaped magnet. 24. The non-contact type position sensor according to claim 1, wherein the magnetic generator comprises a ring-shaped magnet. 25. The non-contact position sensor according to claim 1, wherein the magnetic generator is constituted by a magnet having two arc-shaped magnetic pole surfaces. 26. The magnetic generator according to claim 1, further comprising a positioning hole coaxial with the rotating shaft.
The non-contact type position sensor according to any one of the above.