JP4609516B2 - Displacement detector - Google Patents

Description

  In the present invention, the moving position (moving amount, stroke amount) in the moving direction of a moving body having a non-magnetic body between two first and second magnetic bodies or a moving body (magnetic moving body) made of a magnetic body is determined. The present invention relates to a displacement detection device for detection.

[Conventional technology]
Conventionally, as shown in FIGS. 13 and 14, as a linear displacement detection device, a magnetic moving body 102 that linearly moves (linearly displaces) relative to a flat plate-like magnetic fixed body 101, and this magnetic moving body. Hall IC 103 arranged to face the magnetic moving body 102 at the center in the moving direction of 102, and 2 arranged to face the magnetic moving body 102 at both ends in the moving direction of the magnetic moving body 102. A magnetic potentiometer provided with two first and second magnets 111 and 112 has been proposed (see, for example, Patent Document 1).

The magnetic fixed body 101 includes a first magnetic circuit (J1) connecting the magnetic moving body 102 and the Hall IC 103 via the first magnet 111, and a magnetic moving body 102 and the Hall IC 103 via the second magnet 112. It is a magnetic fixed plate which forms the 2nd magnetic circuit (J2) which connects between.
A projecting portion 113 projecting in a direction approaching the magnetic moving body 102 is provided at the center of the magnetic fixed body 101. The upper end surface in the figure of the protrusion 113 is an IC mounting surface on which the Hall IC 103 is mounted. The illustrated upper end surfaces on both sides of the magnetic fixed body 101 are magnet mounting surfaces for mounting the two first and second magnets 111 and 112, respectively.
The two first and second magnets 111 and 112 are magnetized so that the polarities of the magnetic pole surfaces in contact with the magnet mounting surface of the magnetic fixed body 101 are different from each other.

Conventionally, as shown in FIGS. 15 and 16, for example, a non-contact rotation angle detection device that detects the rotation angle of a valve such as an electronic throttle device is known as a rotation displacement detection device (for example, Patent Documents 2 and 3).
As shown in FIG. 15, this rotation angle detection device is fixed to the magnet holding portion of the final reduction gear 104 of a power transmission mechanism (gear reduction mechanism, etc.) that transmits the rotational driving force of the motor to the shaft that supports the valve. Two first and second magnets 121 and 122, yokes (magnetic bodies) 123 and 124 magnetized by the first and second magnets 121 and 122, and holes arranged in a fixing member such as a sensor cover, for example. It is comprised by IC etc.

Further, as shown in FIG. 16, the rotation angle detection device includes two first and second magnets 131 and 132 fixed to the magnet holding portion of the final reduction gear 104 of the power transmission mechanism (gear reduction mechanism or the like). A yoke (magnetic body: not shown) magnetized by the first and second magnets 131 and 132, a Hall IC 133 fixed to a fixing member such as a sensor cover, and stators 134 and 135 sandwiching the Hall IC 133, etc. It is constituted by.
The final reduction gear 104 is made of resin for the purpose of reducing the weight of, for example, an electronic throttle device, particularly a rotation angle detection device. Further, the final reduction gear 104 has a substantially sector shape in order to form a gear tooth shape.

[Conventional technical problems]
However, in the conventional linear displacement detecting device, the magnetic moving body 102 is linearly moved (stroked) in the moving direction to form the magnetic moving body 102 and the two first and second magnets 111 and 112. The second air gap (G2) is changed in accordance with the stroke amount, and the amount of magnetic flux passing through the Hall IC 103 is also changed in accordance with the stroke amount, so that an output corresponding to the stroke amount is generated from the Hall IC 103. Has been.
However, since the output of the Hall IC 103 is inversely proportional to the square of the second air gap (G2), there is a problem that the linearity of the output characteristics of the Hall IC 103 with respect to the stroke amount of the magnetic moving body 102 is poor.

Further, in the conventional linear displacement detection device, when the magnetic moving body 102 is displaced in a direction (vertical direction in the figure) perpendicular to the moving direction of the magnetic moving body 102, the magnetic moving body 102 is disposed between the Hall IC 103 and the magnetic moving body 102. The first air gap (G1) formed on the surface changes.
As a result, when the magnetic moving body 102 is displaced upward in the drawing, the first air gap (G1) is increased, and the amount of magnetic flux passing through the Hall IC 103 is decreased. Further, when the magnetic moving body 102 is displaced downward in the figure, the first air gap (G1) is reduced, and the amount of magnetic flux passing through the Hall IC 103 is increased.
Therefore, when the magnetic movable body 102 is displaced in the direction perpendicular to the moving direction, there is a problem that output deviation occurs in the output characteristics of the Hall IC 103 with respect to the stroke amount.

  In the conventional rotational displacement detection device (rotation angle detection device), two first and second magnets 121 and 122 or two second magnets for forming a magnetic circuit on the side of the final reduction gear 104 as the detected portion are used. 1 and the second magnets 131 and 132 are arranged. As described above, since the final reduction gear 104 is made of resin, the two first and second magnets 121 and 122 or the two first and second magnets are arranged. A resin molding pressure is applied to the two magnets 131 and 132. For this reason, problems such as cracks and chipping of the two first and second magnets 121 and 122 or the two first and second magnets 131 and 132 occur, and the manufacturing yield is deteriorated. Alternatively, in order to avoid the problem, the two first and second magnets 121 and 122 or the two first and second magnets 131 and 132 are adhesively bonded in a later process after the final reduction gear 104 is resin-molded. In this case, it is necessary to assemble the magnet to the magnet holding portion of the final reduction gear 104, which increases the cost.

Further, when the conventional rotational displacement detection device is applied to the detection of the rotation angle of a valve such as an electronic throttle device, for example, the difference between the linear expansion coefficients increases due to resinization, thereby the two first and second magnets 131. , 132 and the yoke may be misaligned in a direction perpendicular to the moving direction (rotational direction) of the final reduction gear 104 (the radial direction of the final reduction gear 104). As a result, the air gap (G) formed between the detected magnetic circuit such as the two first and second magnets 131 and 132 and the yoke and the Hall IC 133 under a temperature environment varies. There is a problem that the amount of magnetic flux passing through the Hall IC 133 changes and the temperature characteristics are deteriorated.
Japanese Patent Laid-Open No. 9-236644 Japanese Patent No. 3596667 JP 2001-74409 A

  The object of the present invention is to suppress the deterioration of the linearity of the output characteristics of the magnetic sensor with respect to the moving position of the moving body or the magnetic moving body in the moving direction, thereby moving the moving body or the magnetic moving body in the moving direction. An object of the present invention is to provide a displacement detection device capable of improving the detection accuracy of a moving position. Another object of the present invention is to provide a displacement detection device capable of suppressing the influence of the output deviation of the magnetic sensor even when the movable body or the magnetic movable body is displaced in a direction perpendicular to the moving direction. .

According to the first aspect of the present invention, the flow direction of the magnetic flux passing through the first magnetic path and the flow direction of the magnetic flux passing through the second magnetic path of the two first and second magnets are opposite to each other. Is magnetized. Then, the two first elements arranged on both sides in the direction perpendicular to the symmetry axis so that the magnetic fixed body has a symmetric shape centered on the symmetry axis passing through the center of the magnetic sensor. The 2nd division part is provided. The two first and second divided portions are opposed to the magnetic moving body with a gap (second gap: G2) therebetween, and are provided with opposing surfaces parallel to the moving direction of the magnetic moving body. Yes.

Here, the amount of magnetic flux that comes out of the first magnet and passes through the magnetic moving body and the magnetic sensor is such that the opposing surface of the first divided portion of the magnetic fixed body and the magnetic moving body have a gap (second gap: G2). Is changed corresponding to the change in the facing area facing each other. Further, the amount of magnetic flux that comes out of the second magnet and passes through the magnetic moving body and the magnetic sensor is such that the opposing surface of the second divided portion of the magnetic fixed body and the magnetic moving body have a gap (second gap: G2). It changes corresponding to the change of the opposing area which faces apart.
As a result, it is possible to suppress the deterioration of the linearity of the output characteristics of the magnetic sensor with respect to the moving position of the magnetic moving body in the moving direction, and therefore the detection accuracy of the moving position of the magnetic moving body in the moving direction. Can be improved.
In particular, the first magnetic path and the second magnetic path, as air gap, sandwich the magnetic movable element in a direction perpendicular to the moving direction of the magnetic movable element, the gap (second gap: G2) and which separately another gap (the first gap: G1) and of, has only two gaps.
Accordingly, even when the magnetic moving body is displaced in a direction perpendicular to the moving direction, the first gap G1 and the second gap G2 compensate for the increase / decrease in the gap length. The influence of deviation can be suppressed.

According to the second aspect of the present invention, the two first and second divided portions are arranged so as to face each other with a moving body accommodating space for accommodating the magnetic moving body linearly movable in the moving direction. Yes.
According to the third aspect of the present invention, the two first and second divided portions are disposed so as to face each other with at least the magnetic moving body and the magnetic sensor in between.
According to the fourth aspect of the present invention, the two first and second divided portions respectively have opposing portions that face the magnetic moving body with a gap (second gap: G2) therebetween. Each of these facing portions extends in a direction parallel to the moving direction of the magnetic moving body, and is disposed so as to face each other with a predetermined gap.
According to the fifth aspect of the present invention, the opposing portions of the two first and second divided portions are opposite to the magnetic sensor side with respect to the magnetic sensor so as to slightly overlap the magnetic movable body. Has been placed.

According to the sixth aspect of the present invention, the two first and second magnets are arranged closer to the magnetic sensor than the axis of the moving direction of the magnetic moving body. Thereby, the magnetic flux emitted from the two first and second magnets passes through the magnetic moving body and the magnetic sensor.
According to the seventh aspect of the present invention, the magnetic sensor has a magnetosensitive surface facing the magnetic moving body with a gap (first gap: G1) therebetween and parallel to the moving direction of the magnetic moving body. Have.
According to the eighth aspect of the present invention, the magnetic moving body is opposed to the magnetic sensor (the magnetically sensitive surface) with a gap (first gap: G1) therebetween, and with respect to the moving direction of the magnetic moving body. It has a parallel first end face, and faces the opposing faces of the two first and second divided portions with a gap (second gap: G2), and is parallel to the moving direction of the magnetic moving body. A second end face.
Thereby, even when the magnetic moving body is displaced in a direction perpendicular to the moving direction, a gap formed between the magnetic sensor (the magnetic sensitive surface thereof) and the first end face of the magnetic moving body. (First gap: G1) and a gap (second gap: G2) formed between the opposing surfaces of the two first and second divided portions and the second end surface of the magnetic movable body have a gap length of each other. Since the increase and decrease are compensated for, the influence of the output deviation of the magnetic sensor can be suppressed.

According to the ninth aspect of the present invention, the magnetic fixed body has the sensor fixing block on which the magnetic sensor is mounted on the axis of symmetry passing through the central portion of the magnetic sensor. This sensor fixing block has a mounting surface (first magnet mounting surface) for mounting the first magnet and a mounting surface (second magnet mounting surface) for mounting the second magnet.
According to the tenth aspect of the present invention, the two first and second magnets have opposite polarities of the magnetic pole surfaces on the side contacting the mounting surfaces (first and second magnet mounting surfaces) of the sensor fixing block. The sensor fixing block is magnetized (arranged) so as to be polar. Thereby, the flow direction of the magnetic flux emitted from the first magnet and passing through the first magnetic path is opposite to the flow direction of the magnetic flux emitted from the second magnet and passing through the second magnetic path.

According to the eleventh aspect of the present invention, the two first and second magnetic circuits are provided in which the magnetic fluxes emitted from the two first and second magnets flow in opposite directions.
Here, the first magnetic circuit is a magnetic circuit formed by the magnetic flux emitted from the first magnet through the first divided portion of the magnetic moving body, the magnetic sensor, and the magnetic fixed body. The second magnetic circuit is a magnetic circuit formed by magnetic flux that has passed through the second divided portion of the magnetic moving body, the magnetic sensor, and the magnetic fixed body, and has been emitted from the second magnet.

According to the twelfth aspect of the present invention, the opposing surfaces of the two first and second divided portions are opposed to the magnetic moving body with a gap (second gap: G2) therebetween, It is a plane (flat surface) parallel to the moving direction. The magnetic movable body has a plane (flat surface, planar second end surface) that faces each of the opposing surfaces of the two first and second divided portions with a gap (second gap: G2) therebetween. It is formed in a rectangular parallelepiped shape.
According to the invention described in claim 13, the magnetic fixing member has a sensor fixing block on which the magnetic sensor is mounted on an axis of symmetry passing through the central portion of the magnetic sensor. This sensor fixing block is opposed to the magnetic moving body with a gap (first gap: G1) , and has a facing surface parallel to the moving direction of the magnetic moving body. The opposing surface of the sensor fixing block is a plane (flat surface) that faces the magnetic moving body with a gap (first gap: G1) therebetween and is parallel to the moving direction of the magnetic moving body.

According to the fourteenth aspect of the present invention, the opposing surfaces of the two first and second divided portions are curved surfaces (curved surfaces) having a radius of curvature centering on the central axis of the magnetic movable body. In addition, the magnetic moving body has a curved surface (curved surface, curved second end surface) facing the opposing surfaces of the two first and second divided portions with a gap (second gap: G2) therebetween. It is formed in a cylindrical shape.
In this case, even if the magnetic moving body swings around the central axis of the magnetic moving body, the opposing surfaces (curved surfaces) of the two first and second divided portions and the curved surface of the magnetic moving body. And the opposed area facing each other across the gap (second gap: G2) does not change.
Thereby, the linearity (linearity) of the output characteristics of the magnetic sensor with respect to the movement position in the moving direction of the magnetic moving body is improved, and the gap (second gap: G2) becomes narrower or the gap (second gap: G2). ) Can be reduced even when the position is shifted in the widening direction.
According to the fifteenth aspect of the present invention, the magnetic fixed body has a sensor fixing block on which the magnetic sensor is mounted on an axis of symmetry passing through the central portion of the magnetic sensor. This sensor fixing block is opposed to the magnetic moving body with a gap (first gap: G1) , and has a facing surface parallel to the moving direction of the magnetic moving body. The opposing surface of the sensor fixing block is a curved surface (curved surface) having a radius of curvature centered on the central axis of the magnetic moving body.

According to the sixteenth aspect of the present invention, the flow direction of the magnetic flux passing through the first magnetic path and the flow direction of the magnetic flux passing through the second magnetic path of the two first and second magnets are opposite to each other. Is magnetized. Then, the two first elements arranged on both sides in the direction perpendicular to the symmetry axis so that the magnetic fixed body has a symmetric shape centered on the symmetry axis passing through the center of the magnetic sensor. The 2nd division part is provided. The two first and second divided portions are opposed to the magnetic body provided on the moving body with a gap (second gap: G2) therebetween, and opposed surfaces parallel to the moving direction of the moving body. Each is provided.

Here, the amount of magnetic flux that comes out of the first magnet and passes through the magnetic body and the magnetic sensor provided in the moving body is determined by the opposing surface of the first divided portion of the magnetic fixed body and the magnetic body provided in the moving body. It is changed corresponding to a change in the facing area facing each other with a gap (second gap: G2). In addition, the amount of magnetic flux coming out of the second magnet and passing through the magnetic body and the magnetic sensor provided in the moving body is such that the opposing surface of the second divided portion of the magnetic fixed body and the magnetic body provided in the moving body are a gap. It is changed corresponding to the change of the facing area facing each other with (second gap: G2).
As a result, it is possible to suppress the deterioration of the linearity of the output characteristics of the magnetic sensor with respect to the moving position of the moving body in the moving direction, thereby improving the detection accuracy of the moving position of the moving body in the moving direction. Can be made.
The first magnetic path and the second magnetic path, as air gap, sandwich the movable body in a direction perpendicular to the moving direction of the moving body, the gap (second gap: G2) and which with the separately another gap (first gap: G1) and of, has only two gaps.
As a result, even when the moving body is displaced in a direction perpendicular to the moving direction, the first gap G1 and the second gap G2 compensate for the increase / decrease in the gap length. The influence of can be suppressed.

According to the invention described in claim 17, the opposing surfaces of the two first and second divided portions are opposed to the magnetic body provided in the moving body with a gap (second gap: G2) therebetween, It is a plane (flat surface) parallel to the moving direction of the moving body. Further, the magnetic body provided in the moving body faces the opposing surfaces of the two first and second divided portions with a gap (second gap: G2), and is parallel to the moving direction of the moving body. It is formed in a rectangular parallelepiped shape having a flat surface (flat surface, planar second end surface).
According to the invention described in claim 18, the magnetic fixed body has a sensor fixing block on which the magnetic sensor is mounted on an axis of symmetry passing through the center of the magnetic sensor. This sensor fixing block is opposed to a magnetic body provided on the moving body with a gap, and has a facing surface parallel to the moving direction of the moving body. The opposing surface of the sensor fixing block is a plane (flat surface) that faces the magnetic body provided on the moving body with a gap (first gap: G1) therebetween and is parallel to the moving direction of the moving body. is there.

According to the nineteenth aspect of the present invention, the opposing surfaces of the two first and second divided portions are curved surfaces (curved surfaces) having a radius of curvature centering on the central axis of the magnetic body provided in the movable body. . In addition, the magnetic body provided in the moving body is a curved surface (curved surface, curved surface-shaped second surface) facing each opposed surface of the two first and second divided portions with a gap (second gap: G2). It is formed in a cylindrical shape having an end face.
In this case, even if the moving body performs a swinging motion around the central axis of the magnetic body provided on the moving body, the opposing surfaces (curved surfaces) of the two first and second divided portions and the moving body The facing area that faces the curved surface of the magnetic body provided at a distance (second gap: G2) does not change. As a result, the linearity (linearity) of the output characteristics of the magnetic sensor with respect to the moving position of the moving body in the moving direction is improved, and the gap (second gap: G2) is narrowed or the gap (second gap: G2). Even when the position is shifted in the direction of increasing the output, the output shift can be reduced.

According to the twentieth aspect of the present invention, the magnetic fixed body has a sensor fixing block on which the magnetic sensor is mounted on an axis of symmetry passing through the central portion of the magnetic sensor. This sensor fixing block is opposed to a magnetic body provided on the moving body with a gap (first gap: G1) , and has a facing surface parallel to the moving direction of the moving body. The opposing surface of the sensor fixing block is a curved surface (curved surface) with a radius of curvature centering on the central axis of the magnetic body provided on the moving body.
According to the twenty-first aspect of the present invention, the moving body has the non-magnetic body between the two first and second magnetic bodies. That is, two first and second magnetic bodies (for example, a magnetic material such as iron) and a nonmagnetic body (for example, a nonmagnetic material such as aluminum, stainless steel, copper, brass, synthetic resin, and ceramics) are mechanically coupled. A mobile body can be manufactured by combining.

According to a twenty-second aspect of the present invention, the magnetic body provided on the moving body faces the magnetic sensor (the magnetic sensitive surface thereof) with a gap (first gap: G1) therebetween, and the moving direction of the moving body. And opposed to the opposing surfaces of the two first and second divided portions with a gap (second gap: G2) therebetween, with respect to the moving direction of the moving body Second end surfaces parallel to each other.
As a result, even when the moving body is displaced in a direction perpendicular to the moving direction, it is formed between the magnetic sensor (the magnetic sensitive surface thereof) and the first end face of the magnetic body provided on the moving body. Gap (first gap: G1) and a gap (second gap: G2) formed between the opposing surfaces of the two first and second divided portions and the second end surface of the magnetic body provided on the moving body. ) Compensate for the increase / decrease in the gap length, so that the influence of the output deviation of the magnetic sensor can be suppressed.

According to the invention of claim 23, the flow direction of the magnetic flux passing through the first magnetic path and the flow direction of the magnetic flux passing through the second magnetic path of the two first and second magnets are opposite to each other. Is magnetized. The magnetic fixed body is provided with two first and second divided portions respectively arranged on both sides in a direction perpendicular to the symmetry axis passing through the central portion of the magnetic sensor. The two first and second divided portions are opposed to the magnetic body provided on the moving body with a gap (second gap: G2) therebetween, and the moving body moves in the moving direction (rotating direction, rotating locus). An opposing surface (an opposing surface parallel to the moving direction of the moving body) that is curved is provided.

Here, the amount of magnetic flux that comes out of the first magnet and passes through the magnetic body and the magnetic sensor provided in the moving body is determined by the opposing surface of the first divided portion of the magnetic fixed body and the magnetic body provided in the moving body. It is changed corresponding to a change in the facing area facing each other with a gap (second gap: G2). In addition, the amount of magnetic flux coming out of the second magnet and passing through the magnetic body and the magnetic sensor provided in the moving body is such that the opposing surface of the second divided portion of the magnetic fixed body and the magnetic body provided in the moving body are a gap. It is changed corresponding to the change of the facing area facing each other with (second gap: G2).
As a result, it is possible to suppress the deterioration of linearity (linearity) of the output characteristics of the magnetic sensor with respect to the moving position (rotational position, rotational displacement amount) in the moving direction (rotating direction) of the moving body. The detection accuracy of the movement position (rotation position, rotation displacement amount) in the movement direction (rotation direction) can be improved.
The first magnetic path and the second magnetic path, as air gap, sandwich the movable body in a direction perpendicular to the moving direction of the moving body (rotational direction), the gap (second gap: G2) and Apart from this, there are only two gaps, another gap (first gap: G1).
As a result, even when the moving body is displaced in a direction perpendicular to the moving direction (rotating direction), the first gap G1 and the second gap G2 compensate for increase / decrease in the gap length. The influence of the output deviation of the sensor can be suppressed.

According to the twenty-fourth aspect of the present invention, the opposing surfaces of the two first and second divided portions are concave curved surfaces having a radius of curvature centering around the central portion of the magnetic sensor held and fixed to the magnetic fixed body ( Curved surface). Further, the magnetic body provided in the moving body is opposed to the opposing surfaces of the two first and second divided portions with a gap (second gap: G2), and is curved along the moving direction of the moving body. It is formed in a partial cylindrical shape having a convex curved surface (curved surface, curved second end surface).
According to a twenty-fifth aspect of the present invention, the magnetic fixed body has a sensor fixing block on which the magnetic sensor is mounted on an axis of symmetry passing through the center of the magnetic sensor. This sensor fixing block is opposed to a magnetic body provided on the moving body with a gap (first gap: G1), and is opposed to a curved surface along the moving direction of the moving body (with respect to the moving direction of the moving body). Parallel opposing surfaces). The opposing surface of the sensor fixing block is a convex curved surface (curved surface) with a radius of curvature centering around the center of the magnetic sensor held and fixed to the magnetic fixing body.

According to the twenty-sixth aspect of the present invention, the magnetic body provided in the moving body faces the magnetic sensor (the magnetically sensitive surface) with a gap (first gap: G1) therebetween, and the moving direction of the moving body Having a concave curved surface (a concave curved surface parallel to the moving direction of the moving body, the first end surface) and a gap (second second) with respect to the opposing surfaces of the two first and second divided portions. It has a convex curved surface (a convex curved surface parallel to the moving direction of the moving body, the second end surface) that faces the gap G2) and curves along the moving direction of the moving body.
As a result, even when the moving body is displaced in a direction perpendicular to the moving direction (rotation direction, rotation trajectory), the concave portion of the magnetic sensor (the magnetic sensitive surface thereof) and the magnetic body provided on the moving body is Gap (first gap: G1) formed between the curved surface (first end surface) and the convex surfaces (second end surface) of the magnetic body provided on the opposing surfaces of the two first and second divided portions and the movable body ) And the gap (second gap: G2) formed between each other compensate for the increase and decrease of the gap length, so that the influence of the output deviation of the magnetic sensor can be suppressed.
According to a twenty-seventh aspect of the present invention, the magnetic body provided in the moving body is formed in a partial cylindrical shape extending in an arc shape along the moving direction (rotating direction, rotation locus) of the moving body.

  The best mode for carrying out the present invention is to improve the detection accuracy of the moving position of the moving body or the magnetic moving body in the moving direction, and to improve the detection accuracy of the moving position of the moving body or the magnetic moving body in the moving direction. This was achieved by suppressing the deterioration of the linearity of the sensor output characteristics. In addition, even when the moving body or the magnetic moving body is displaced in a direction perpendicular to the moving direction, the magnetic body provided on the moving body or the object of suppressing the influence of the output displacement of the magnetic sensor Each of the first end face, the concave curved surface, and the two first and second divided portions of the magnetic fixed body facing the magnetic moving body with a gap (first gap: G1) with respect to the magnetic sensitive surface of the magnetic sensor. This is realized by providing a second end face and a convex curved face that face each other with a gap (second gap: G2) from the opposite face.

[Configuration of Example 1]
1 and 2 show a first embodiment of the present invention, and FIG. 1 shows a linear displacement detector.

The internal combustion engine (hereinafter referred to as the engine) of this embodiment is equipped with a linear displacement detection device that detects linear displacement (linear motion, linear motion) of the control shaft of the variable valve mechanism. This linear displacement detection device is a moving body (moving body made of magnetic material: hereinafter referred to as a magnetic moving body) that linearly moves in the moving direction (stroke direction) in accordance with the linear displacement in the moving direction of the control shaft of the variable valve mechanism. ) 1, a magnetic sensor 2 disposed to face the magnetic moving body 1, and two first and second magnets (magnets) 3 that emit magnetic flux toward the magnetic moving body 1 and the magnetic sensor 2, 4 and a magnetic fixing body for holding and fixing the magnetic sensor 2 and the two first and second magnets 3 and 4.
Here, the magnetic fixed body is a magnetic fixed block fixed in the vicinity of the engine, with respect to a sensor fixed block 5 on which the magnetic sensor 2 is mounted (held and fixed), and a symmetrical axis passing through the center of the magnetic sensor 2. The first and second divided blocks 6 and 7 are arranged on both sides in the vertical direction.

In the linear displacement detection device, magnetic fluxes emitted from the two first and second magnets 3 and 4 are mutually connected by the magnetic moving body 1, the magnetic sensor 2, the two first and second magnets 3 and 4, and the magnetic fixed body. Two first and second magnetic circuits (J1, J2) flowing in opposite directions are formed.
The magnetic moving body 1 is a moving magnetic body (magnetic moving block) formed of a magnetic material (magnetic body) such as iron from the left end in the drawing to the right end in the drawing. The magnetic moving body 1 is formed in a rectangular parallelepiped shape, and has a planar first end face (lower side in the figure) facing the magnetic sensing surface of the magnetic sensor 2 with a first air gap (air gap 1: G1) therebetween. End surface) and a second end surface having a planar shape facing each other with a second air gap (air gap 2: G2) between the opposing surfaces of the two first and second divided blocks 6 and 7 of the magnetic fixed body. (Upper end face in the figure).

  The magnetic sensor 2 of this embodiment is opposed to the first end face of the magnetic moving body 1 with a first air gap (G1) therebetween, and is parallel to the axis of the magnetic moving body 1 in the stroke direction. (One magnetosensitive surface). The magnetic sensor 2 is mounted on the sensor mounting surface so that the other magnetic sensitive surface is in contact with the sensor mounting surface of the sensor fixing block 5. The magnetic sensor 2 has a Hall IC that detects the magnetic flux emitted from the two first and second magnets 3 and 4. In addition, the magnetic sensor 2 integrates a Hall element that constitutes a non-contact type magnetic detection element whose output changes according to the magnetic flux density interlinking the Hall IC and an amplifier circuit that amplifies the output of the Hall element. A voltage signal (output signal) corresponding to the magnetic flux density interlinking the Hall IC is generated. Thereby, the sensor output voltage is output from the magnetic sensor 2 toward the engine control unit (engine control unit: ECU).

  The two first and second magnets 3 and 4 are respectively arranged on both sides in a direction perpendicular to the symmetric axis so as to have a symmetric positional relationship about the symmetric axis passing through the center of the magnetic sensor 2. Has been placed. The first and second magnets 3 and 4 have a flow direction of magnetic flux passing through the first magnetic path formed in the magnetic fixed body and a flow direction of magnetic flux passing through the second magnetic path formed in the magnetic fixed body. They are magnetized so that they are opposite to each other. In addition, the two first and second magnets 3 and 4 are arranged such that the polarities of the magnetic pole surfaces on the side contacting the first and second magnet mounting surfaces of the sensor fixing block 5 of the magnetic fixed body are opposite to each other. Magnetized.

The two first and second magnets 3 and 4 are disposed on the magnetic sensor side with respect to the axis line in the stroke direction of the magnetic moving body 1.
The first magnet 3 is disposed in a gap formed between the first magnet mounting surface of the sensor fixing block 5 and the first magnet mounting surface of the first divided block 6. Specifically, the first magnet 3 is held and fixed to the first magnet mounting surface of the sensor fixing block 5 and the first magnet mounting surface of the first divided block 6 by using a fixing means such as an adhesive.
The second magnet 4 is disposed in a gap formed between the second magnet mounting surface of the sensor fixing block 5 and the second magnet mounting surface of the second divided block 7. Specifically, the second magnet 4 is held and fixed to the second magnet mounting surface of the sensor fixing block 5 and the second magnet mounting surface of the second divided block 7 using a fixing means such as an adhesive.
The two first and second magnets 3 and 4 have a rectangular shape (or square shape) in plan view, and are, for example, rare earth magnets such as samarium-cobalt (Sm-Co) magnets and neodymium (Nd) magnets, alnico magnets. Ferrite magnets and resin magnets are used, and are rectangular parallelepiped permanent magnets that continuously generate magnetic force for a long period of time.

The magnetic fixed body is a fixed magnetic body formed of a magnetic material such as iron. The magnetic fixed body includes a sensor fixing block 5 fixed to a fixing member (not shown), and two first and second divided blocks 6 and 7 that form two first and second magnetic paths together with the sensor fixing block 5. have.
The sensor fixing block 5 is formed in a rectangular parallelepiped shape, and is disposed on an axis of symmetry passing through the center of the magnetic sensor 2. The sensor fixing block 5 includes a planar sensor mounting surface for mounting the magnetic sensor 2, a planar first magnet mounting surface for mounting the first magnet 3, and a planar second magnet mounting surface for mounting the second magnet 4. have. The sensor fixing block 5 is formed with a first magnetic path connecting a sensor mounting surface on which the magnetic sensor 2 is mounted and a first magnet mounting surface on which the first magnet 3 is mounted. The sensor fixing block 5 is formed with a second magnetic path connecting the sensor mounting surface on which the magnetic sensor 2 is mounted and the second magnet mounting surface on which the second magnet 4 is mounted.

  The two first and second divided blocks 6, 7 have a U-shaped cross section, and the symmetry axis thereof so as to have a symmetric shape about the symmetry axis passing through the center of the magnetic sensor 2. Are arranged on both sides in a direction perpendicular to the direction. The first and second divided blocks 6 and 7 are arranged so as to face each other with a moving body accommodating space 9 in which the magnetic moving body 1 is accommodated so as to be linearly movable in the stroke direction. Further, the two first and second divided blocks 6 and 7 are opposed to each other with the magnetic moving body 1, the magnetic sensor 2, the two first and second magnets 3 and 4 and the sensor fixing block 5 interposed therebetween. Has been placed.

  The two first and second divided blocks 6, 7 are parallel to the stroke direction axis of the magnetic movable body 1 on the two first and second magnet sides with respect to the stroke direction axis of the magnetic movable body 1. Projections 11 and 16 project in the direction and close to each other. Two first and second magnet attachment surfaces that are in contact with the magnetic pole surfaces of the two first and second magnets 3 and 4 are formed on the protrusions 11 and 16, respectively. These first and second magnet mounting surfaces extend in a direction perpendicular to the axis of the magnetic moving body 1 in the stroke direction.

The two first and second divided blocks 6 and 7 are provided with vertical portions 12 and 15 extending in a direction perpendicular to the stroke direction axis of the magnetic mobile body 1 on both sides of the magnetic mobile body 1 in the stroke direction. Have.
Further, the two first and second divided blocks 6 and 7 are arranged on the opposite side to the two first and second magnet sides with respect to the two axial directions of the magnetic moving body 1 in the stroke direction. It has opposing portions (extensions) 13 and 14 that are arranged to face the end surface with a second air gap (G2) therebetween and extend in a direction parallel to the axis of the magnetic moving body 1 in the stroke direction. is doing. The facing portions 13 and 14 of the first and second divided blocks 6 and 7 are arranged so as to face each other with a predetermined gap (gap in the stroke direction of the magnetic moving body 1: gap).

The opposing portions 13 and 14 of the two first and second divided blocks 6 and 7 are arranged so as to slightly overlap the magnetic movable body 1. Further, the facing portions 13 and 14 of the two first and second divided blocks 6 and 7 face the second end face of the magnetic moving body 1 with a second air gap (G2) therebetween, and the magnetic moving body Each has an opposing surface parallel to the axis of one stroke direction.
And the 1st division block 6 forms the 1st magnetic path which connects between the 1st magnet attachment surface which attaches the 1st magnet 3, and the counter surface which opposes the 2nd end face of magnetic movement object 1. Further, the second divided block 7 is formed with a second magnetic path connecting the second magnet mounting surface on which the second magnet 4 is mounted and the facing surface facing the second end surface of the magnetic moving body 1.

The first magnetic circuit (J1) is formed by a magnetic flux that passes through the magnetic moving body 1, the magnetic sensor 2, and the magnetic fixed body (the sensor fixing block 5 and the first divided block 6) and is emitted from the first magnet 3. . This first magnetic circuit (J1) is formed in the first magnetic path formed between the magnetic sensor 2 and the first magnet 3 formed in the sensor fixing block 5, and in the first divided block 6. A first magnetic path connecting the magnet 3 and the magnetic moving body 1 is included.
Thereby, the magnetic flux emitted from the magnetic pole surface (N pole) of the first magnet 3 is changed to the first divided block 6 (projection 11 → vertical portion 12 → opposing portion 13) → second air gap (G2) → magnetic moving body. 1 → First air gap (G1) → Magnetic sensor 2 (Hall IC) → Sensor fixing block 5 returns to the magnetic pole surface (S pole) of the first magnet 3.

The second magnetic circuit (J2) is formed by the magnetic flux emitted from the second magnet 4 after passing through the magnetic moving body 1, the magnetic sensor 2, and the magnetic fixed body (the sensor fixed block 5 and the second divided block 7). . The second magnetic circuit (J2) is formed in the sensor fixing block 5, the second magnetic path connecting the magnetic sensor 2 and the second magnet 4, and the second divided block 7, the second magnetic circuit (J2). A second magnetic path connecting the magnet 4 and the magnetic moving body 1 is included.
Thereby, the magnetic flux emitted from the magnetic pole surface (N pole) of the second magnet 4 is changed from the sensor fixing block 5 to the magnetic sensor 2 (Hall IC) → the first air gap (G1) → the magnetic moving body 1 → the second air gap. It returns to the magnetic pole surface (S pole) of the second magnet 4 through the path of (G2) → second divided block 7 (opposing portion 14 → vertical portion 15 → projecting portion 16).
Therefore, in the linear displacement detection device of the present embodiment, the magnetic flux emitted from the magnetic pole surfaces (N poles) of the two first and second magnets 3 and 4 is converted into two first and second magnetic circuits (J1, J2) flows in opposite directions.

[Detection Method of Example 1]
Next, a detection method of the linear displacement detection apparatus of this embodiment will be briefly described with reference to FIGS. Here, FIG. 2 is a characteristic diagram showing the stroke amount of the magnetic moving body with respect to the magnetic flux amount passing through the magnetic sensor.

When the control shaft of the variable valve mechanism moves in the axial direction, the magnetic moving body 1 connected to the control shaft moves linearly in the stroke direction.
At this time, the facing area where the second end face of the magnetic moving body 1 and the facing surface of the facing portion 13 of the first divided block 6 of the magnetic fixed body face each other changes according to the stroke amount of the magnetic moving body 1. Further, according to the stroke amount of the magnetic moving body 1, the facing area where the second end surface of the magnetic moving body 1 and the facing surface of the facing portion 14 of the second divided block 7 of the magnetic fixed body face each other changes.

  The amount of magnetic flux that comes out of the magnetic pole surface (N pole) of the first magnet 3 and passes through the first magnetic circuit (J1: magnetic moving body 1 and magnetic sensor 2) is the same as that of the second end surface of the magnetic moving body 1. The first divided block 6 is changed in accordance with the change in the facing area with the facing surface of the facing portion 13. Further, the amount of magnetic flux that comes out of the magnetic pole surface (N pole) of the second magnet 4 and passes through the second magnetic circuit (J2: magnetic sensor 2 and magnetic moving body 1) is the same as that of the second end surface of the magnetic moving body 1. The second divided block 7 is changed in accordance with the change in the facing area with the facing surface of the facing portion 14.

Here, in the linear displacement detection device of the present embodiment, the flow direction of the magnetic flux passing through the first magnetic circuit (J1) including the first magnetic path and the second magnetic circuit (J2) including the second magnetic path are passed. The magnetic pole surfaces of the two first and second magnets 3 and 4 (the magnetic pole surfaces on the side in contact with the sensor fixing block 5) have opposite polarities. It arrange | positions so that it may become.
Note that the maximum stroke amount from the initial position (position in FIG. 1) of the magnetic movable body 1 to the maximum movement position is, for example, 8 mm.

  Therefore, when the stroke amount of the magnetic moving body 1 is small (for example, 0 mm), the magnetic moving body 1 is arranged on the left side in the drawing in the moving body accommodating space 9 as shown in FIG. Thereby, the opposing area of the 2nd end surface of the magnetic mobile body 1 and the opposing surface of the opposing part 13 of the 1st division | segmentation block 6 is the 2nd end surface of the magnetic mobile body 1, and the opposing part 14 of the 2nd division | segmentation block 7. Therefore, the influence of the magnetic flux of the first magnet 3 becomes stronger. Therefore, as shown in the graph of FIG. 2, the magnetic sensor 2 (Hall IC) detects the amount of magnetic flux (or magnetic flux density) in the positive direction. As a result, the output signal (sensor signal) of the magnetic sensor 2 (Hall IC) is a positive voltage corresponding to the facing area between the second end surface of the magnetic moving body 1 and the facing surface of the facing portion 13 of the first divided block 6. Signal.

  When the stroke of the magnetic moving body 1 is large (for example, when it is 8 mm), the magnetic moving body 1 is arranged on the right side in the drawing in the moving body accommodating space 9. Thereby, the second end face of the magnetic movable body 1 and the opposed portion 14 of the second divided block 7 are opposed to the opposed area of the second end face of the magnetic movable body 1 and the opposed surface of the opposed portion 13 of the first divided block 6. Since the facing area with the facing surface becomes wider, the influence of the magnetic flux of the second magnet 4 becomes stronger. Therefore, as shown in the graph of FIG. 2, the magnetic sensor 2 (Hall IC) detects the amount of magnetic flux (or magnetic flux density) in the negative direction. As a result, the output signal (sensor signal) of the magnetic sensor 2 (Hall IC) is a negative voltage corresponding to the facing area between the second end surface of the magnetic moving body 1 and the facing surface of the facing portion 14 of the second divided block 7. Signal.

Further, when the stroke amount of the magnetic movable body 1 is 4 mm, for example, the magnetic movable body 1 is disposed at the center position in the movable body accommodating space 9. In this case, the facing area between the second end face of the magnetic moving body 1 and the facing face of the facing portion 13 of the first divided block 6 is equal to the second end face of the magnetic moving body 1 and the facing portion 14 of the second divided block 7. Therefore, the magnetic flux emitted from the first magnet 3 and the magnetic flux emitted from the second magnet 4 cancel each other. For this reason, the amount of magnetic flux (or magnetic flux density) detected by the magnetic sensor 2 (Hall IC) is zero (0) as shown in the graph of FIG. As a result, the output signal (sensor signal) of the magnetic sensor 2 (Hall IC) becomes zero (0).
The ECU calculates a linear displacement amount (stroke amount) of the control shaft based on the voltage signal output from the magnetic sensor 2 (Hall IC), and the intake valve (or exhaust valve) of the engine based on the stroke amount. ) Is calculated.

[Effect of Example 1]
As described above, in the linear displacement detection device of the present embodiment, the flow direction of magnetic flux passing through the first magnetic circuit (J1) including the first magnetic path and the second magnetic circuit (J2) including the second magnetic path. The two first and second magnets 3 and 4 are magnetized so that the flow directions of the magnetic flux passing through the magnets are opposite to each other. That is, the two first and second magnets 3 and 4 are arranged in the gaps of the magnetic fixed body so that the polarities of the magnetic pole surfaces (the magnetic pole surfaces on the side contacting the sensor fixing block 5) are opposite to each other. (Magnetized).
And the magnetic mobile body 1 which carries out a linear displacement relatively with respect to a magnetic fixed body (magnetic fixed block) is connected with the control shaft of the variable valve mechanism as a detection target.

  The magnetic fixed body includes a sensor fixing block 5 and two first and second divided blocks 6 and 7. The magnetic sensor 2 is mounted on the sensor mounting surface of the sensor fixing block 5. In addition, the two first and second divided blocks 6 and 7 have symmetrical axes that pass through the central portion of the magnetic sensor 2 so that they are symmetrical about the symmetrical axis that passes through the central portion of the magnetic sensor 2. They are arranged on both sides in a direction perpendicular to the respective sides. The two first and second divided blocks 6 and 7 are provided with facing portions 13 and 14 that face the second end face of the magnetic moving body 1 with a second air gap (G2) therebetween. . The opposed lower end surfaces of the facing portions 13 and 14 are opposed to the second end surface of the magnetic moving body 1 with a second air gap (G2) therebetween, and are parallel to the stroke direction of the magnetic moving body 1. Opposing surfaces are formed respectively. And each opposing part 13 and 14 of two 1st, 2nd division | segmentation blocks 6 and 7 is arrange | positioned on the opposite side with respect to the magnetic sensor side rather than the magnetic moving body 1 so that the magnetic moving body 1 may be overlapped a little. Has been.

  Here, the amount of magnetic flux coming out of the magnetic pole surface (N pole) of the first magnet 3 and passing through the first magnetic circuit (J1: the magnetic moving body 1 and the magnetic sensor 2) is the first divided block of the magnetic fixed body. The facing surface of the facing portion 13 and the second end surface of the magnetic movable body 1 are changed in response to a change in facing area facing each other across the second air gap (G2). Further, the amount of magnetic flux that comes out of the magnetic pole surface (N pole) of the second magnet 4 and passes through the second magnetic circuit (J2: magnetic sensor 2 and magnetic moving body 1) is the opposing portion 14 of the second divided block 7. The opposite surface and the second end surface of the magnetic movable body 1 are changed in accordance with the change in the opposed area that faces the second air gap (G2).

Thereby, in the linear displacement detection apparatus of the present embodiment, the opposing surfaces of the opposing portions 13 and 14 of the two first and second divided blocks 6 and 7 are opposed to the second end surface of the magnetic movable body 1. By changing the area in proportion to the stroke amount of the magnetic moving body 1 in the stroke direction, the amount of magnetic flux passing through the magnetic sensor 2 (Hall IC) via the magnetic moving body 1 is linearly changed. It becomes possible to make it. Thereby, the output signal output from the magnetic sensor 2 changes linearly according to the stroke amount of the magnetic moving body 1 in the stroke direction.
Accordingly, it is possible to suppress the deterioration of the linearity of the output characteristics of the magnetic sensor 2 with respect to the stroke amount of the magnetic moving body 1 in the stroke direction. Detection accuracy can be improved.

A first air gap (G1) having a predetermined gap length is formed between the first end face of the magnetic moving body 1 and the magnetic sensitive surface of the magnetic sensor 2. In addition, a second air gap (having a predetermined gap length) is formed between the second end surface of the magnetic movable body 1 and the opposing surfaces of the opposing portions 13 and 14 of the two first and second divided blocks 6 and 7. G2) is formed.
Accordingly, even if the magnetic moving body 1 is displaced in a direction perpendicular to the stroke direction (the positional displacement direction in FIG. 1), the first air gap (G1) and the second air gap (G2) ) Compensate for the increase / decrease in the gap length, so that the influence of the output deviation of the magnetic sensor 2 can be suppressed. For example, when the first air gap (G1) is increased, the second air gap (G2) is decreased accordingly. Conversely, when the first air gap (G1) is reduced, the second air gap (G2) is increased accordingly.

FIG. 3 shows a second embodiment of the present invention and is a diagram showing a linear displacement detector.
As in the first embodiment, the linear displacement detection apparatus of the present embodiment includes a magnetic moving body (magnetic moving block) 1, a magnetic sensor 2, two first and second magnets 3, 4 and a magnetic fixed body (magnetic fixed block). ).

The magnetic moving body 1 of the present embodiment is a moving body made of a magnetic body (magnetic material) such as iron in the same manner as in the first embodiment. Along with this, it moves linearly in the movement direction (stroke direction).
In addition, the magnetic fixing body of the present embodiment has a sensor fixing block 5 having a transverse E-shaped cross section and two first and second divided blocks 6 and 7 having an inverted L-shaped cross section. .
The sensor fixing block 5 has a base portion 19 extending in a direction parallel to the axis of the magnetic movable body 1 in the stroke direction. A sensor fixing portion 20 protruding upward in the figure is integrally provided at the center portion of the base portion 19. The sensor fixing portion 20 is formed in a rectangular parallelepiped shape and is disposed on an axis of symmetry passing through the central portion of the magnetic sensor 2. And the sensor fixing | fixed part 20 is made into the planar sensor mounting surface where the illustration upper end surface mounts the magnetic sensor 2. FIG.

Two first and second magnet mounting portions 21 and 22 projecting upward in the figure are integrally provided at both ends of the base portion 19. These first and second magnet mounting portions 21 and 22 are arranged at the center of the magnetic sensor 2 so as to have a symmetric shape (or positional relationship) about the axis of symmetry passing through the center of the magnetic sensor 2. They are arranged on both sides in a direction perpendicular to the passing symmetry axis. The two first and second magnet attachment portions 21, 22 have a planar first magnet attachment surface to which the first magnet 3 is attached and a planar second portion to which the second magnet 4 is attached. It is a magnet mounting surface.
Here, the sensor fixing block 5 of the present embodiment is formed with a first magnetic path connecting the sensor mounting surface on which the magnetic sensor 2 is mounted and the first magnet mounting surface on which the first magnet 3 is mounted. The sensor fixing block 5 is formed with a second magnetic path connecting the sensor mounting surface on which the magnetic sensor 2 is mounted and the second magnet mounting surface on which the second magnet 4 is mounted.

  The two first and second divided blocks 6 and 7 are respectively arranged on both sides in a direction perpendicular to the symmetric axis so as to have a symmetric shape around the symmetric axis passing through the center of the magnetic sensor 2. Has been placed. As in the first embodiment, the first and second divided blocks 6 and 7 are arranged so as to face each other with a moving body accommodating space 9 that accommodates the magnetic moving body 1 linearly movable in the stroke direction. ing. Further, the two first and second divided blocks 6 and 7 are arranged so as to face each other with the sensor moving part 1, the magnetic sensor 2 and the sensor fixing part 20 of the sensor fixing block 5 interposed therebetween.

  The two first and second divided blocks 6, 7 have vertical portions 12, 15 extending in a direction perpendicular to the axis of the magnetic moving body 1 in the stroke direction on both sides in the stroke direction of the magnetic moving body 1. ing. Two first and second magnet attachment surfaces that are in contact with the magnetic pole surfaces of the two first and second magnets 3 and 4 are formed on the lower end surfaces of the vertical portions 12 and 15 in the figure. These first and second magnet mounting surfaces extend in a direction parallel to the axis of the magnetic moving body 1 in the stroke direction.

Further, the two first and second divided blocks 6 and 7 have facing portions 13 and 14 as in the first embodiment. Further, the facing portions 13 and 14 of the two first and second divided blocks 6 and 7 face the second end face of the magnetic moving body 1 with a second air gap (G2) therebetween, and the magnetic moving body Each has an opposing surface parallel to the axis of one stroke direction.
And the 1st division block 6 forms the 1st magnetic path which connects between the 1st magnet attachment surface which attaches the 1st magnet 3, and the counter surface which opposes the 2nd end face of magnetic movement object 1. Further, the second divided block 7 is formed with a second magnetic path connecting the second magnet mounting surface on which the second magnet 4 is mounted and the facing surface facing the second end surface of the magnetic moving body 1.

The first magnetic circuit (J1) is formed by a magnetic flux that passes through the magnetic moving body 1, the magnetic sensor 2, and the magnetic fixed body (the sensor fixing block 5 and the first divided block 6) and is emitted from the first magnet 3. . This first magnetic circuit (J1) is formed in the first magnetic path formed between the magnetic sensor 2 and the first magnet 3 formed in the sensor fixing block 5, and in the first divided block 6. A first magnetic path connecting the magnet 3 and the magnetic moving body 1 is included.
Thereby, the magnetic flux emitted from the magnetic pole surface (N pole) of the first magnet 3 is changed into the first divided block 6 (vertical portion 12 → opposing portion 13) → second air gap (G2) → magnetic moving body 1 → first. On the magnetic pole surface (S pole) of the first magnet 3 along the path of air gap (G1) → magnetic sensor 2 (Hall IC) → sensor fixing block 5 (sensor fixing portion 20 → base portion 19 → first magnet mounting portion 21). Return.

The second magnetic circuit (J2) is formed by the magnetic flux emitted from the second magnet 4 after passing through the magnetic moving body 1, the magnetic sensor 2, and the magnetic fixed body (the sensor fixed block 5 and the second divided block 7). . The second magnetic circuit (J2) is formed in the sensor fixing block 5, the second magnetic path connecting the magnetic sensor 2 and the second magnet 4, and the second divided block 7, the second magnetic circuit (J2). A second magnetic path connecting the magnet 4 and the magnetic moving body 1 is included.
Thereby, the magnetic flux emitted from the magnetic pole surface (N pole) of the second magnet 4 is changed to the sensor fixing block 5 (second magnet mounting portion 22 → base portion 19 → sensor fixing portion 20) → magnetic sensor 2 (Hall IC) → On the magnetic pole surface (S pole) of the second magnet 4 along the path of the first air gap (G1) → the magnetic moving body 1 → the second air gap (G2) → the second divided block 7 (opposite portion 14 → vertical portion 15). Return.
As a result, the same effect as in the first embodiment can be achieved.

FIG. 4 shows a third embodiment of the present invention and shows a linear displacement detector.
The linear displacement detection apparatus of the present embodiment includes a magnetic sensor 2, two first and second magnets 3, 4, a magnetic fixed body (magnetic fixed block), and two first and second magnetic bodies 31, 32. A body (movable body) 10 is provided.

The moving body 10 of the present embodiment is formed in a rectangular parallelepiped shape, and has a non-magnetic body 33 between the two first and second magnetic bodies 31 and 32.
The first magnetic body 31 is a first magnetic moving body formed of a magnetic material such as iron, and a magnetic body (magnetic fixed body, magnetic fixed block) 17 coupled to the magnetic sensitive surface of the magnetic sensor 2. A first end surface (a flat surface, a flat surface, a lower end surface in the drawing) opposed to each other with a first air gap (G1) therebetween, and a facing surface of the facing portion 13 of the first divided block 6 of the magnetic fixed body A planar second end surface (a flat surface, a flat surface, or an upper end surface in the drawing) facing each other with a second air gap (G2) therebetween is provided.

The second magnetic body 32 is a second magnetic moving body formed of a magnetic material such as iron, and a first air gap (G1) between the second magnetic body 32 and the magnetic body 17 coupled to the magnetic sensitive surface of the magnetic sensor 2. A second air gap (G2) between the planar first end face (plane, flat face, lower end face in the drawing) facing each other and the opposing face of the opposing portion 14 of the second divided block 7 of the magnetic fixed body And a planar second end face (a flat face, a flat face, and an upper end face in the figure) facing each other.
The non-magnetic body 33 is a non-magnetic moving body formed of a non-magnetic material such as aluminum, stainless steel, copper, brass, synthetic resin, ceramics, etc., and two first, The second magnetic bodies 31 and 32 are coupled.

The magnetic fixed body of the present embodiment has a sensor fixing block 5 formed in a rectangular parallelepiped shape, two first and second divided blocks 6 and 7 formed in a U-shape, and a magnetic body 17. . The magnetic body 17 is disposed on the magnetic sensitive surface of the magnetic sensor 2 and holds and fixes the magnetic sensor 2 between the sensor mounting block 5 and the sensor mounting surface.
Further, the two first and second divided blocks 6 and 7 have facing portions 13 and 14 as in the first embodiment. In addition, the opposing portions 13 and 14 of the two first and second divided blocks 6 and 7 are respectively second of the first and second magnetic bodies 31 and 32 provided at both ends of the moving body 10 in the stroke direction. Opposite surfaces are opposed to the end surface with a second air gap (G2) therebetween and are parallel to the axis of the moving body 10 in the stroke direction.
And the 1st division | segmentation block 6 opposes the 1st magnet attachment surface which attaches the 1st magnet 3, and the 2nd end surface of the 1st magnetic body 31 provided in the end (left end of illustration) of the moving body 10 at the stroke direction. Is formed. The second divided block 7 is opposed to the second magnet mounting surface to which the second magnet 4 is mounted and the second end surface of the second magnetic body 32 provided at the other end (right end in the drawing) of the moving body 10 in the stroke direction. A second magnetic path connecting between the surfaces is formed.

The first magnetic circuit (J1) passes through the first magnetic body 31, the magnetic sensor 2, and the magnetic fixed body (the sensor fixed block 5, the first divided block 6, and the magnetic body 17) of the moving body 10, and the first magnet 3 It is formed by the magnetic flux emitted from. The first magnetic circuit (J1) is formed in the magnetic body 17, the first magnetic path connecting the first magnetic body 31 and the magnetic sensor 2, and the magnetic sensor 2 formed in the sensor fixing block 5. The first magnetic path connecting the first magnet 3 and the first magnetic path connecting the first magnet 3 and the first magnetic body 31 formed in the first divided block 6 are included.
Thereby, the magnetic flux emitted from the magnetic pole surface (N pole) of the first magnet 3 is changed to the first divided block 6 (protruding portion 11 → vertical portion 12 → facing portion 13) → second air gap (G2) → moving body 10. (First magnetic body 31) → first air gap (G1) → magnetic fixed body (magnetic body 17) → magnetic sensor 2 (Hall IC) → magnetic pole surface (S pole) of the first magnet 3 along the path of the sensor fixing block 5 Return to).

The second magnetic circuit (J2) passes through the second magnetic body 32, the magnetic sensor 2 and the magnetic fixed body (the sensor fixing block 5, the second divided block 7, and the magnetic body 17) of the moving body 10, and the second magnet 4 It is formed by the magnetic flux emitted from. The second magnetic circuit (J2) is formed on the magnetic sensor 17, the second magnetic path formed between the second magnetic body 32 and the magnetic sensor 2, and the magnetic sensor 2 formed on the sensor fixing block 5. The second magnetic path that connects the second magnet 4 and the second magnetic path that is formed in the second divided block 7 and connects the second magnet 4 and the second magnetic body 32 are included.
Thereby, the magnetic flux emitted from the magnetic pole surface (N pole) of the second magnet 4 is changed from the sensor fixing block 5 to the magnetic sensor 2 (Hall IC) → the magnetic fixing body (magnetic body 17) → the first air gap (G1) → The magnetic pole surface (S pole) of the second magnet 4 along the path of the moving body 10 (second magnetic body 32) → second air gap (G2) → second divided block 7 (opposing portion 14 → vertical portion 15 → projecting portion 16). Return to).
As a result, the same effect as in the first embodiment can be achieved.

[Configuration of Example 4]
5 to 7 show a fourth embodiment of the present invention, and FIG. 5 shows a linear displacement detector.
Here, the linear displacement detection device of the first embodiment is a linear displacement sensor that detects linear displacement (linear motion, linear motion) of a control shaft of a variable valve mechanism of an internal combustion engine (engine). This linear displacement sensor has a structure that performs a swinging motion about the moving direction of a moving body (magnetic moving body 1) made of a magnetic body.

As shown in FIG. 8, the linear displacement detection apparatus according to the first embodiment is configured so that the second end face (plane) of the rectangular parallelepiped magnetic moving body 1 and the two first and second divided blocks 6 and 7 face each other. The structure is such that the linear output is extracted from the magnetic sensor 2 (Hall IC) by varying the area where the facing surfaces (planes) of the portions 13 and 14 face each other.
However, since the second end surface of the magnetic moving body 1 and the opposing surfaces of the opposing portions 13 and 14 of the two first and second divided blocks 6 and 7 are both planar, as described above, In the configuration in which the swinging motion is performed with the moving direction of the magnetic moving body 1 as an axis, the second end surface of the magnetic moving body 1 and the facing surfaces of the facing portions 13 and 14 of the two first and second divided blocks 6 and 7 are used. There is a possibility that the second air gap (air gap 2: G2) formed between the magnetic sensor 2 and the magnetic sensor 2 (Hall IC) output (sensor output) will not be linear.

Therefore, in the linear displacement detection device of the present embodiment, as shown in FIGS. 5 and 6, the two first and second magnetic bodies 31 and 32 constituting the moving body 10 and the first and second of these are provided. The non-magnetic body 33 disposed between the magnetic bodies 31 and 32 has a cylindrical shape. And the 1st end surface and 2nd end surface of the two 1st, 2nd magnetic bodies 31 and 32 of the moving body 10 are cylindrical outer peripheral surfaces (convex curved surface). Note that the first and second magnetic bodies 31 and 32 and the non-magnetic body 33 are coupled by mechanical coupling such as welding or adhesion.
In addition, the magnetic fixing body of the present embodiment has a sensor fixing block 5 having an inverted convex cross section, two first and second divided blocks 6 and 7 having an L-shaped cross section, and a magnetic body 17. is doing.

The sensor fixing block 5 is integrally provided with a sensor fixing portion 20 protruding downward in the figure at the center of the base portion 19.
The magnetic body 17 is disposed on the magnetic sensitive surface of the magnetic sensor 2 and holds and fixes the magnetic sensor 2 between the sensor mounting portion 20 and the sensor mounting surface. This magnetic body 17 has a circular arc inner peripheral surface (the shape of the facing portion 39 facing the cylindrical outer peripheral surface of the cylindrical moving body 10 (particularly, the outer peripheral surfaces of the two first and second magnetic bodies 31 and 32). It has an arc shape having a facing surface. The facing portion 39 of the magnetic body 17 faces the cylindrical outer peripheral surfaces (first end surfaces) of the two first and second magnetic bodies 31 and 32 of the moving body 10 with a first air gap (G1) therebetween. The moving body 10 has an opposing surface parallel to the axis of the stroke direction. The facing surface of the facing portion 39 of the magnetic body 17 is a concave curved surface (curved surface) with a radius of curvature centering on the central axis of the first magnetic body 31 of the moving body 10.

The two first and second divided blocks 6 and 7 have vertical portions 12 and 15 that extend in a direction perpendicular to the axis of the moving body 10 in the stroke direction on both sides of the moving body 10 in the stroke direction. . Two first and second magnet attachment surfaces that are in contact with the magnetic pole surfaces of the two first and second magnets 3 and 4 are formed on the illustrated upper end surfaces of the vertical portions 12 and 15, respectively.
The first divided block 6 has a cylindrical inner peripheral surface (opposing surface) in which the shape of the opposing portions 41 and 42 that oppose the cylindrical outer peripheral surface of the cylindrical movable body 10 (particularly, the cylindrical outer peripheral surface of the first magnetic body 31). ) And an arc shape having an arc inner peripheral surface (opposing surface). The facing portions 41 and 42 of the first divided block 6 face the cylindrical outer peripheral surface (second end surface) of the first magnetic body 31 of the moving body 10 with a second air gap (G2) therebetween, and the moving body 10 It has an opposing surface parallel to the axis in the stroke direction. The facing surfaces of the facing portions 41 and 42 of the first divided block 6 are concave curved surfaces (curved surfaces) having a radius of curvature with the central axis of the first magnetic body 31 of the moving body 10 as the center.

  Further, the second divided block 7 has a cylindrical inner peripheral surface (opposing surface) in the shape of the opposing portions 43 and 44 that oppose the cylindrical outer peripheral surface of the cylindrical moving body 10 (particularly the cylindrical outer peripheral surface of the second magnetic body 32). ) And an arc shape having an arc inner peripheral surface (opposing surface). The facing portions 43 and 44 of the second divided block 6 face the cylindrical outer peripheral surface (second end surface) of the second magnetic body 32 of the moving body 10 with a second air gap (G2) therebetween, and the moving body 10 It has an opposing surface parallel to the axis in the stroke direction. The facing surfaces of the facing portions 43 and 44 of the second divided block 7 are concave curved surfaces (curved surfaces) having a radius of curvature centering on the central axis of the second magnetic body 32 of the moving body 10.

As shown in FIGS. 6A and 6B, the first magnetic circuit (J1) includes the first magnetic body 31, the magnetic sensor 2, and the magnetic fixed body (sensor fixing block 5, first division) of the moving body 10. It is formed by the magnetic flux emitted from the first magnet 3 through the block 6 and the magnetic body 17). The first magnetic circuit (J1) is formed in the sensor fixing block 5, a first magnetic path connecting the magnetic sensor 2 and the first magnet 3, and a first magnet formed in the first divided block 6. 3 and the first magnetic body 31 that connects the first magnetic body 31 of the moving body 10 and the first magnetic path that is formed on the magnetic body 17 and connects the first magnetic body 31 of the moving body 10 and the magnetic sensor 2. Includes magnetic path.
Thereby, the magnetic flux emitted from the magnetic pole surface (N pole) of the first magnet 3 is changed to the first divided block 6 (vertical portion 12 → opposing portions 41, 42) → second air gap (G2) → first of the moving body 10. 1st magnet in the path of 1 magnetic body 31 → first air gap (G1) → magnetic fixed body (magnetic body 17) → magnetic sensor 2 (Hall IC) → sensor fixing block 5 (sensor fixing portion 20 → base portion 19) 3 returns to the magnetic pole surface (S pole).

As shown in FIGS. 6B and 6C, the second magnetic circuit (J2) includes the second magnetic body 32 of the moving body 10, the magnetic sensor 2, and the magnetic fixed body (sensor fixing block 5, second divided). It is formed by magnetic flux emitted from the second magnet 4 through the block 7 and the magnetic body 17). The second magnetic circuit (J2) is formed in the sensor fixing block 5, a second magnetic path connecting the magnetic sensor 2 and the second magnet 4, and a second magnet formed in the second divided block 7. 4 and the second magnetic body 32 that connects the second magnetic body 32 of the moving body 10 and the second magnetic path that is formed on the magnetic body 17 and connects the second magnetic body 32 of the moving body 10 and the magnetic sensor 2. Includes magnetic path.
Thereby, the magnetic flux emitted from the magnetic pole surface (N pole) of the second magnet 4 is changed to the sensor fixing block 5 (base portion 19 → sensor fixing portion 20) → magnetic sensor 2 (Hall IC) → magnetic fixed body (magnetic body 17). ) → first air gap (G1) → second magnetic body 32 of the moving body 10 → second air gap (G2) → second divided block 7 (opposing portions 44, 43 → vertical portion 15) through the second magnet Return to the magnetic pole face (S pole) of No. 4.

[Detection Method of Example 4]
Next, a detection method of the linear displacement detection device of this embodiment will be briefly described with reference to FIGS. Here, FIG. 7 is a characteristic diagram showing the stroke amount of the moving body with respect to the magnetic flux amount passing through the magnetic sensor (Hall IC).

When the control shaft of the variable valve mechanism moves in the axial direction, the moving body 10 connected to the control shaft moves linearly in the stroke direction.
At this time, according to the stroke amount of the moving body 10, the second end surface (convex curved surface) of the first magnetic body 31 of the moving body 10 and the facing surfaces of the facing portions 41 and 42 of the first divided block 6 of the magnetic fixed body ( The facing area opposite to the (concave curved surface) changes. Moreover, according to the stroke amount of the moving body 10, the 2nd end surface (convex curved surface) of the 2nd magnetic body 32 of the moving body 10 and the opposing surfaces (concave) of the opposing parts 44 and 43 of the 2nd division | segmentation block 7 of a magnetic fixed body are demonstrated. The facing area facing the curved surface changes.

  The amount of magnetic flux that comes out of the magnetic pole surface (N pole) of the first magnet 3 and passes through the first magnetic circuit (J1: the first magnetic body 31 and the magnetic sensor 2 of the moving body 10) is The first magnetic body 31 is changed corresponding to a change in the facing area between the second end face (convex curved surface) of the first magnetic body 31 and the facing surfaces (concave curved face) of the facing portions 41 and 42 of the first divided block 6. Further, the amount of magnetic flux that comes out of the magnetic pole surface (N pole) of the second magnet 4 and passes through the second magnetic circuit (J2: the magnetic sensor 2 and the second magnetic body 32 of the moving body 10) is The second magnetic body 32 is changed in accordance with the change in the facing area between the second end face (convex curved surface) of the second magnetic body 32 and the facing surfaces (concave curved face) of the facing portions 44 and 43 of the second divided block 7.

Here, in the linear displacement detection device of the present embodiment, the flow direction of magnetic flux passing through the first magnetic circuit (J1) including the first magnetic path and the second magnetic path including the second magnetic path are the same as in the first embodiment. The magnetic flux surfaces passing through the two magnetic circuits (J2) are opposite to each other, that is, the magnetic pole surfaces of the two first and second magnets 3 and 4 (the magnetic poles on the side in contact with the sensor fixing block 5) Are arranged on the magnetic fixed body so that the polarities of the surface are opposite to each other.
Note that the maximum stroke amount from the initial position of the moving body 10 (the position shown in FIG. 6A) to the maximum moving position is, for example, 8 mm.

  Therefore, when the stroke of the moving body 10 is small (for example, 0 mm), the moving body 10 is arranged on the right side in the drawing in the moving body accommodation space 9 as shown in FIG. Thereby, the opposing area of the 2nd end surface (convex curved surface) of the 1st magnetic body 31 of the moving body 10 and the opposing surfaces (concave curved surface) of the opposing parts 41 and 42 of the 1st division | segmentation block 6 is the moving body 10 direction. Since the opposing area of the second end surface (convex curved surface) of the second magnetic body 32 and the opposing surfaces (concave curved surface) of the opposing portions 44 and 43 of the second divided block 7 is smaller, the magnetic flux of the first magnet 3 is reduced. The influence becomes stronger. Therefore, as shown in the graph (state 1) in FIG. 7, the magnetic sensor 2 (Hall IC) detects the amount of magnetic flux (or magnetic flux density) in the positive direction. As a result, the output signal (sensor signal) of the magnetic sensor 2 (Hall IC) is opposed to the second end face (convex curved surface) of the first magnetic body 31 of the moving body 10 and the facing portions 41 and 42 of the first divided block 6. This is a positive voltage signal corresponding to the area facing the surface (concave surface).

  Further, when the stroke amount of the moving body 10 is, for example, 4 mm, the moving body 10 is arranged at the center position in the moving body accommodating space 9 as shown in FIGS. 5 and 6B. In this case, the facing area between the second end face (convex curved surface) of the first magnetic body 31 of the moving body 10 and the facing surfaces (concave curved face) of the facing portions 41 and 42 of the first divided block 6 is the moving body 10. Since the opposing area of the second end surface (convex curved surface) of the second magnetic body 32 and the opposing surfaces (concave curved surface) of the opposing portions 44 and 43 of the second divided block 7 is the same, The emitted magnetic flux and the magnetic flux emitted from the second magnet 4 are offset. For this reason, the amount of magnetic flux (or magnetic flux density) detected by the magnetic sensor 2 (Hall IC) is zero (0) as shown in the graph (state 2) of FIG. As a result, the output signal (sensor signal) of the magnetic sensor 2 (Hall IC) becomes zero (0).

Further, when the stroke amount of the moving body 10 is large (for example, 8 mm), the moving body 10 is arranged on the left side in the drawing in the moving body accommodating space 9 as shown in FIG. Accordingly, the moving body 10 has a larger area than the facing area between the second end surface (convex curved surface) of the first magnetic body 31 of the moving body 10 and the facing surfaces (concave curved surfaces) of the facing portions 41 and 42 of the first divided block 6. Since the facing area between the second end surface (convex curved surface) of the second magnetic body 32 and the facing surfaces (concave curved surface) of the facing portions 44 and 43 of the second divided block 7 becomes narrower, the magnetic flux of the second magnet 4 is reduced. The influence becomes stronger. Therefore, as shown in the graph (state 3) in FIG. 7, the magnetic sensor 2 (Hall IC) detects the amount of magnetic flux (or magnetic flux density) in the negative direction. As a result, the output signal (sensor signal) of the magnetic sensor 2 (Hall IC) is the opposite of the second end face (convex curved surface) of the second magnetic body 32 of the moving body 10 and the facing portions 44 and 43 of the second divided block 7. This is a negative voltage signal corresponding to the area facing the surface (concave surface).
The ECU calculates a linear displacement amount (stroke amount) of the control shaft based on the voltage signal output from the magnetic sensor 2 (Hall IC), and the intake valve (or exhaust valve) of the engine based on the stroke amount. ) Is calculated.

[Effect of Example 4]
As described above, in the linear displacement detection device of this embodiment, the same effect as that of Embodiment 1 can be achieved.
Even if the moving body 10 swings around the central axes of the two first and second magnetic bodies 31 and 32 of the moving body 10, the opposing portion 39 of the magnetic body 17 of the magnetic fixed body The opposing surface (circular arc inner peripheral surface: concave curved surface) and the cylindrical outer peripheral surfaces (convex curved surfaces) of the two first and second magnetic bodies 31 and 32 of the moving body 10 are opposed to each other across the first air gap (G1). The facing area does not change. Furthermore, two opposing first and second surfaces of the movable body 10 and the opposing surfaces of the opposing portions 41 to 44 of the two first and second divided blocks 6 and 7 (cylindrical inner peripheral surface, arc inner peripheral surface: concave curved surface). The facing area in which the cylindrical outer peripheral surfaces (convex curved surfaces) of the magnetic bodies 31 and 32 face each other across the second air gap (G2) does not change.
As a result, the linearity of the output characteristics of the magnetic sensor 2 with respect to the moving position of the moving body 10 in the moving direction is improved, and the vertical direction in the figure, for example, the first and second air gaps (G1, G2) are narrowed. Even when the position is shifted in the direction or the direction in which the first and second air gaps (G1, G2) are widened, the output shift can be reduced.

FIG. 9 shows Embodiment 5 of the present invention, and FIGS. 9A to 9C are views showing a method of manufacturing a moving body having two first and second magnetic bodies.
As shown in FIG. 9A, the moving body 10 of the present embodiment first forms the columnar body 50 of a nonmagnetic material such as aluminum, stainless steel, copper, brass, synthetic resin, ceramics or the like.
At this time, the outer diameters of both end portions in the axial direction of the cylindrical body 50 (the stroke direction of the moving body 10) are made smaller than the outer diameter of the central portion. As a result, the large-diameter nonmagnetic body 33 is formed at the central portion of the cylindrical body 50 in the axial direction, and the nonmagnetic bodies 51 and 52 having a smaller diameter than the nonmagnetic body 33 are formed at both ends of the cylindrical body 50 in the axial direction. Is done.

Next, as shown in FIG. 9B, thin plate-like first and second magnetic plates (iron plates) 53 and 54 are formed of a magnetic material such as iron. The two first and second magnetic plates 53 and 54 may be wound around the cylindrical outer peripheral surfaces of the nonmagnetic members 51 and 52 so as to surround the cylindrical outer peripheral surfaces of the nonmagnetic members 51 and 52 of the cylindrical member 50 in the circumferential direction. The steel plate is formed by punching or cutting or plastic working so as to have a possible size.
Next, the first and second magnetic plates 53 and 54 are wound around the cylindrical outer peripheral surfaces of the nonmagnetic bodies 51 and 52 of the cylindrical body 50, and are joined by mechanical coupling such as welding or adhesion, so that the nonmagnetic body The moving body 10 having two first and second magnetic bodies 31 and 32 on both sides in the axial direction of 33 can be manufactured.

FIG. 10 shows Embodiment 6 of the present invention and is a diagram showing a linear displacement detector.
In the linear displacement detection apparatus of the present embodiment, the moving body 10 of the fourth embodiment is changed to a moving body (magnetic moving body 1) made of a magnetic body having the same configuration as in the first and second embodiments.
Also by this, the same effect as in the fourth embodiment can be achieved.

[Configuration of Example 7]
11 and 12 show a seventh embodiment of the present invention, and FIG. 11 shows a rotational displacement detecting device.
The engine of this embodiment is equipped with an electronic throttle device that controls the amount of intake air supplied into the combustion chamber.

  The electronic throttle device drives a throttle body that is coupled in the middle of an intake duct of an engine, a throttle valve that opens and closes the inside (intake passage) of the throttle body, a shaft that supports and fixes the throttle valve, and a throttle valve An actuator including a motor, and an engine control unit (ECU) that controls the valve angle (rotation angle) of the throttle valve by variably controlling the power supplied to the motor according to the operating state of the engine.

  Here, an actuator (valve driving device) for driving the throttle valve shaft in the valve opening operation direction or the valve closing operation direction is a motor that generates a rotational driving force for driving the throttle valve when supplied with electric power, and the motor. It is an electric actuator comprised including the power transmission mechanism for transmitting the rotational driving force of this to a shaft. The power transmission mechanism is constituted by a gear reduction mechanism that reduces the rotational speed of the motor to a predetermined reduction ratio and increases the rotational driving force of the motor. The gear reduction mechanism includes a pinion gear (motor side gear) fixed to the output shaft of the motor, an intermediate reduction gear that rotates in mesh with the pinion gear, and a final reduction gear (valve side gear) that rotates in mesh with the intermediate reduction gear. have. Of the three gears constituting the gear reduction mechanism, at least the final reduction gear is integrally formed of a synthetic resin so as to have a predetermined gear shape.

The electronic throttle device converts the throttle opening corresponding to the rotation angle of the throttle valve that is driven to open (or close) according to the throttle operation amount of the driver into an electronic signal, A non-contact rotation angle detection device (non-contact position sensor: hereinafter referred to as a rotation displacement detection device) that outputs whether the throttle valve is open is mounted.
The rotational displacement detection device is a rotational angle sensor (throttle opening sensor) for detecting the rotational angle of a throttle valve, and is a magnetic moving body 1, a magnetic sensor 2, and two first, Second magnets (first and second magnets) 3 and 4 and a magnetic fixed body (magnetic fixed block) are provided. In addition, the rotational displacement detection device uses the magnetic sensor 2, the two first and second magnets 3, 4 and the magnetic fixed body to cause the magnetic fluxes emitted from the two first and second magnets 3, 4 to be opposite to each other. Two flowing first and second magnetic circuits (J1, J2) are formed.

The magnetic moving body 1 is made of a partially cylindrical soft magnetic body extending in an arc along the moving direction (stroke direction, rotation direction) of the magnetic moving body 1. The magnetic moving body 1 is a magnetic moving body (magnetic moving block) formed of a magnetic material such as iron, and is held and fixed to the final reduction gear of the electronic throttle device.
Further, the magnetic moving body 1 is connected between the convex surface (the outer wall surface of the magnetic body 57 in the bending direction) of the magnetic body (magnetic fixing body, magnetic fixing block) 57 coupled to the magnetic sensitive surface of the magnetic sensor 2. 1st end surface of the concave curved surface shape that is opposed across one air gap (air gap 1: G1), and opposed surfaces of the curved portions 61 and 62 of the two first and second divided blocks 6 and 7 of the magnetic fixed body A convex-curved second end surface (convex curved surface) is provided between the curved portions 61 and 62 and the second air gap (air gap 2: G2).
The first end surface of the magnetic moving body 1 is curved in an arc shape along the moving direction (rotating direction) of the magnetic moving body 1 and the convex curved surface of the magnetic body 57, and has a radius of curvature centered around the center of the magnetic sensor 2. A concave curved surface (a wall surface on the inner side in the bending direction of the magnetic movable body 1). Further, the second end face of the magnetic moving body 1 is curved in an arc shape along the moving direction (rotating direction) of the magnetic moving body 1, and is a convex curved surface (having a radius of curvature centered around the center of the magnetic sensor 2). This is the outer wall surface of the magnetic moving body 1 in the bending direction.

In the magnetic sensor 2, one magnetic sensitive surface is in contact with the sensor mounting surface (plane) of the magnetic body 57 of the magnetic fixed body, and the other magnetic sensitive surface is a magnetic body (sensor fixing portion) of the magnetic fixed body. 60 is in contact with the sensor mounting surface (plane). As in the first embodiment, the magnetic sensor 2 has a Hall IC that detects magnetic fluxes emitted from the two first and second magnets 3 and 4.
As in the first embodiment, the two first and second magnets 3 and 4 are symmetrical with respect to the symmetry axis so that they are symmetrical about the symmetry axis passing through the center of the magnetic sensor 2. They are arranged on both sides in the vertical direction. These first and second magnets 3 and 4 are magnetized so that the polarities of the magnetic pole surfaces on the side contacting the first and second magnet mounting surfaces of the sensor fixing block 5 of the magnetic fixed body are opposite to each other. Has been.

The two first and second magnets 3 and 4 are disposed closer to the magnetic sensor 2 than the magnetic moving body 1. The two first and second magnets 3 and 4 may be disposed anywhere as long as they are closer to the magnetic sensor 2 than the magnetic moving body 1.
The first magnet 3 is disposed in a gap formed between the first magnet mounting surface of the base portion 59 of the magnetic fixed body and the first magnet mounting surface of the curved portion 61 of the magnetic fixed body.
The second magnet 4 is disposed in a gap formed between the second magnet mounting surface of the base portion 59 of the magnetic fixed body and the second magnet mounting surface of the curved portion 62 of the magnetic fixed body.
The two first and second magnets 3 and 4 are rectangular parallelepiped permanent magnets having a rectangular planar shape (or square shape) and continuously generating a magnetic force for a long period of time.

The magnetic fixed body includes a sensor fixing block 5 on which the magnetic sensor 2 is mounted and a magnetic body 57. The magnetic body 57 is formed in a partial circular shape, is disposed on the magnetically sensitive surface of the magnetic sensor 2, and sandwiches the magnetic sensor 2 between the sensor mounting surface of the sensor fixing portion 60 of the sensor fixing block 5. It is held and fixed with. The upper end surface of the magnetic body 57 shown in the figure is a sensor mounting surface (flat surface) that comes into contact with the magnetic sensitive surface of the magnetic sensor 2. In addition, the lower end surface of the magnetic body 57 shown in the figure is curved in an arc along the moving direction (rotating direction) of the magnetic moving body 1 and has a convex curved surface (magnetic This is the outer wall surface of the body 57 in the bending direction.
The sensor fixing block 5 is disposed on an axis of symmetry passing through the center of the magnetic sensor 2, and has a partially cylindrical base 59, and a rectangular parallelepiped sensor fixing that protrudes downward from the center of the base 59. 60 and two first and second divided blocks (first and second divided portions) 6 and 7 formed in a partial cylindrical shape. That is, the sensor fixing block 5 has a C-shaped magnetic material (two curved portions constituting the base portion 59 and two first portions) so that the magnetic flux flows in the opposite directions in the left and right magnetic fixed bodies shown in the drawing. The curved portions 61 and 62) of the second divided blocks 6 and 7 are assembled.

The two first and second divided blocks 6 and 7 have partially cylindrical curved portions (opposing portions) 61 and 62 extending in an arc shape along the moving direction (rotating direction) of the magnetic moving body 1. . The first and second divided blocks 6 and 7 are disposed so as to face the magnetic sensitive surface of the magnetic sensor 2 with the magnetic moving body 1 and the magnetic body 57 sandwiched between the magnetic sensor 2 and the magnetic sensor 2.
The curved portions 61 and 62 of the two first and second divided blocks 6 and 7 face the second end face of the magnetic moving body 1 with a second air gap (air gap 2: G2) therebetween, and are magnetic. The moving body 1 has a moving surface (rotating direction) and a facing surface curved in a circular arc along the second end face (convex curved surface) of the magnetic moving body 1 (a facing surface parallel to the moving direction of the moving body). is doing. The opposing surfaces of the curved portions 61 and 62 of the two first and second divided blocks 6 and 7 are curved along the rotation locus (movement direction, rotation direction) of the magnetic moving body 1, and the center portion of the magnetic sensor 2. It is a concave curved surface (a wall surface or curved surface on the inner side in the bending direction of the curved portions 61 and 62) having a radius of curvature centered around the vicinity.
The curved portion 61 of the first divided block 6 is formed with a first magnetic path that connects between the first magnet mounting surface on which the first magnet 3 is mounted and the facing surface facing the second end surface of the magnetic moving body 1. Is done. In addition, the curved portion 62 of the second divided block 7 is formed with a second magnetic path that connects between the second magnet mounting surface on which the second magnet 4 is mounted and the facing surface facing the second end surface of the magnetic moving body 1. The

The first magnetic circuit (J1) passes through the magnetic moving body 1, the magnetic sensor 2, and the magnetic fixed body (the sensor fixed block 5, the first divided block 6, and the magnetic body 57), and the magnetic flux emitted from the first magnet 3 It is formed by. The first magnetic circuit (J1) is formed in the magnetic body 57, the first magnetic path connecting the magnetic movable body 1 and the magnetic sensor 2, and the magnetic sensor 2 and the first magnetic path formed in the sensor fixing block 5. The first magnetic path that connects between the first magnet 3 and the first magnetic path that is formed in the first divided block 6 and connects between the first magnet 3 and the magnetic moving body 1 is included.
Thereby, the magnetic flux emitted from the magnetic pole surface (N pole) of the first magnet 3 is changed from the first divided block 6 (curved portion 61) to the second air gap (air gap 2: G2) to the magnetic moving body 1 (soft magnetism). Body) → first air gap (air gap 1: G1) → magnetic fixed body (magnetic body 57) → magnetic sensor 2 (Hall IC) → sensor fixing block 5 (sensor fixing part 60 → base part 59) 1 Return to the magnetic pole surface (S pole) of the magnet 3.

The second magnetic circuit (J2) passes through the magnetic moving body 1, the magnetic sensor 2, and the magnetic fixed body (the sensor fixed block 5, the second divided block 7, and the magnetic body 57), and the magnetic flux emitted from the second magnet 4 It is formed by. The second magnetic circuit (J2) is formed in the magnetic body 57, the second magnetic path connecting the magnetic mobile body 1 and the magnetic sensor 2, and the magnetic sensor 2 and the second magnetic path formed in the sensor fixing block 5. The second magnetic path that connects the two magnets 4 and the second magnetic path that is formed in the second divided block 7 and connects the second magnet 4 and the magnetic moving body 1 are included.
As a result, the magnetic flux emitted from the magnetic pole surface (N pole) of the second magnet 4 is changed to the sensor fixing block 5 (base portion 59 → sensor fixing portion 60) → magnetic sensor 2 (Hall IC) → magnetic fixed body (magnetic body 57). ) → first air gap (air gap 1: G1) → magnetic moving body 1 (soft magnetic body) → second air gap (air gap 2: G2) → second divided block 7 (curved portion 62) 2 Return to the magnetic pole surface (S pole) of the magnet 4.

[Detection Method of Example 7]
Next, a detection method of the rotational displacement detection device of the present embodiment will be briefly described with reference to FIGS. Here, FIG. 12 is a characteristic diagram showing the rotational displacement (rotation angle) of the moving body with respect to the magnetic flux passing through the magnetic sensor (Hall IC).

When the throttle valve of the electronic throttle device is rotationally displaced in its rotational direction, the magnetic movable body 1 held and fixed to the final reduction gear coupled to one end portion of the throttle valve shaft in the rotational axis direction moves in a curved line in the stroke direction. (Rotation motion is performed around the center of the magnetic sensor 2).
At this time, according to the rotational displacement amount (rotation angle) in the rotation direction of the magnetic moving body 1, the second end face (convex curved surface) of the magnetic moving body 1 and the bending portion 61 of the first divided block 6 of the magnetic fixed body are arranged. The facing area where the facing surface (concave curved surface) faces changes. Further, the second end surface (convex curved surface) of the magnetic moving body 1 and the curved portion 62 of the second divided block 7 of the magnetic fixed body are opposed in accordance with the rotational displacement amount (rotational angle) in the rotational direction of the magnetic moving body 1. The facing area where the surface (concave curved surface) faces changes. The opposing area where the first end surface (concave surface) of the magnetic moving body 1 and the convex surface of the magnetic body 57 of the magnetic fixed body face each other is such that the first end surface of the magnetic moving body 1 is along the convex surface of the magnetic body 57. Therefore, even if the amount of rotational displacement (rotational angle) in the rotational direction of the magnetic mobile body 1 changes, the magnetic movable body 1 does not change.

  The amount of magnetic flux that comes out of the magnetic pole surface (N pole) of the first magnet 3 and passes through the first magnetic circuit (J1: the magnetic moving body 1 and the magnetic sensor 2) is the second end face ( It is changed corresponding to the change in the facing area between the convex curved surface) and the opposing surface (concave curved surface) of the curved portion 61 of the first divided block 6. Further, the amount of magnetic flux that comes out of the magnetic pole surface (N pole) of the second magnet 4 and passes through the second magnetic circuit (J2: magnetic sensor 2 and magnetic moving body 1) is the second end surface (of the magnetic moving body 1). It is changed corresponding to the change in the facing area between the convex surface) and the opposing surface (concave surface) of the curved portion 62 of the second divided block 7.

Here, in the rotational displacement detector of the present embodiment, the flow direction of the magnetic flux passing through the first magnetic circuit (J1) including the first magnetic path and the second magnetic circuit (J2) including the second magnetic path are passed. The magnetic flux surfaces of the two first and second magnets 3 and 4 (the magnetic pole surfaces on the side in contact with the sensor fixing block 5 and the two first and second magnetic pole surfaces). The magnetic fixed body is arranged so that the polarities of the magnetic pole surfaces on the side contacting the two divided blocks 6 and 7 are opposite to each other.
The maximum amount of rotational displacement (rotatable range) in the rotational direction from the initial rotational position (limit position) to the maximum rotational position (limit position) of the magnetic mobile body 1 is set to 100 °, for example.

  Therefore, when the rotational displacement amount (rotation angle) in the rotation direction of the magnetic mobile body 1 is small (for example, at −50 °), as shown by the two-dot chain line (A) in FIG. 1 is disposed on the right side in the figure in the rotational direction in the moving body accommodation space. Thereby, the opposing area of the 2nd end surface (convex curved surface) of the magnetic mobile body 1 and the opposing surface (concave curved surface) of the curved part 61 of the 1st division | segmentation block 6 is the 2nd end surface (convex) of the magnetic mobile body 1. Since the surface area of the second divided block 7 and the opposing surface (concave surface) of the curved portion 62 of the second divided block 7 are larger than each other, the influence of the magnetic flux of the first magnet 3 is increased. Therefore, as shown in the graph of FIG. 12, the magnetic sensor 2 (Hall IC) detects the amount of magnetic flux (or magnetic flux density) in the positive direction. As a result, an output signal (sensor signal) of the magnetic sensor 2 (Hall IC) is generated between the second end surface (convex curved surface) of the magnetic moving body 1 and the opposing surface (concave curved surface) of the curved portion 61 of the first divided block 6. It becomes a positive voltage signal corresponding to the facing area.

  Further, when the rotational displacement amount (rotation angle) in the rotational direction of the magnetic mobile body 1 is, for example, 0 °, the magnetic mobile body 1 is centered in the rotational direction in the mobile body accommodating space as shown by the solid line in FIG. Placed in position. In this case, the opposing area between the second end face (convex curved surface) of the magnetic moving body 1 and the opposing face (concave curved face) of the curved portion 61 of the first divided block 6 is the second end face (convex convex) of the magnetic moving body 1. Curved surface) and the facing area of the opposing surface (concave curved surface) of the curved portion 62 of the second divided block 7, the magnetic flux emitted from the first magnet 3 and the magnetic flux emitted from the second magnet 4. Are offset. For this reason, the amount of magnetic flux (or magnetic flux density) detected by the magnetic sensor 2 (Hall IC) is zero (0) as shown in the graph of FIG. As a result, the output signal (sensor signal) of the magnetic sensor 2 (Hall IC) becomes zero (0).

Further, when the rotational displacement amount (rotation angle) in the rotation direction of the magnetic mobile body 1 is large (for example, at 50 °), as shown by a two-dot chain line (B) in FIG. Is arranged on the left side in the rotational direction in the moving body accommodation space. Accordingly, the second end face (convex curved surface) of the magnetic mobile body 1 is larger than the facing area between the second end face (convex curved face) of the magnetic moving body 1 and the opposing face (concave curved face) of the curved portion 61 of the first divided block 6. ) And the facing area (concave surface) of the curved portion 62 of the second divided block 7 is wider, so that the influence of the magnetic flux of the second magnet 4 becomes stronger. For this reason, as shown in the graph of FIG. 12, the magnetic sensor 2 (Hall IC) detects the amount of magnetic flux (or magnetic flux density) in the negative direction. As a result, an output signal (sensor signal) of the magnetic sensor 2 (Hall IC) is generated between the second end surface (convex curved surface) of the magnetic moving body 1 and the opposing surface (concave curved surface) of the curved portion 62 of the second divided block 7. It becomes a negative voltage signal corresponding to the facing area.
Then, the ECU calculates the rotational displacement (rotation angle) of the magnetic mobile body 1 based on the voltage signal output from the magnetic sensor 2 (Hall IC), and throttles based on the rotational displacement (rotation angle). The throttle opening corresponding to the rotation angle of the valve is calculated.

[Effect of Example 7]
As described above, in the rotational displacement detection device of the present embodiment, the opposing surfaces of the curved portions 61 and 62 of the two first and second divided blocks 6 and 7 and the second end surface of the magnetic movable body 1 are opposed to each other. The magnetic sensor 2 is changed via the magnetic moving body 1 and the magnetic body 57 by proportionally changing the facing area to be changed according to the rotational displacement amount (rotational angle) in the moving direction (rotating direction) of the magnetic moving body 1. It is possible to linearly change the amount of magnetic flux (sensor output) passing through (Hall IC). And the magnetic mobile body 1 which is a to-be-detected member is formed only with the soft magnetic body of the partial cylindrical shape. That is, since the first reduction gear (resin gear) is not provided with the two first and second magnets 3 and 4, the magnet (two first and second magnets) at the resin molding pressure at the time of resin molding of the final reduction gear. The occurrence of problems such as cracks and chipping of the second magnets 3 and 4) can be prevented. Thereby, the manufacturing yield can be improved at low cost. Furthermore, the output signal output from the magnetic sensor 2 changes linearly according to the amount of rotational displacement of the magnetic moving body 1 in the rotational direction.
Further, even when deformation occurs due to the difference in linear expansion coefficient, the air gap amount does not change as in the first embodiment, and the wide angle range can be detected with high accuracy.
Accordingly, it is possible to suppress the deterioration of linearity (linearity) of the output characteristics of the magnetic sensor 2 with respect to the rotational displacement amount (rotation angle) in the rotational direction of the magnetic mobile body 1 made of a soft magnetic material. The detection accuracy of the rotational displacement amount (rotation angle) of the body 1 can be improved.

A first air gap (air gap 1) having a predetermined gap length is formed between the first end face of the magnetic moving body 1 and the magnetic sensitive surface of the magnetic sensor 2 (in this embodiment, the convex curved surface of the magnetic body 57). : G1) is formed. In addition, a second air gap having a predetermined gap length (between the second end surface of the magnetic moving body 1 and the opposing surfaces of the curved portions 61 and 62 of the two first and second divided blocks 6 and 7). Air gap 2: G2) is formed.
As a result, even if the magnetic moving body 1 is displaced in a direction perpendicular to the moving direction (rotating direction) (the radial direction of the throttle valve shaft or the final reduction gear: the vertical direction in the figure), the air Since the gap 1 and the air gap 2 compensate for the increase / decrease in the gap length, the influence of the positional deviation in the radial direction and the influence of the output deviation of the magnetic sensor 2 are reduced with respect to the moving direction (rotating direction) of the magnetic moving body 1 be able to. For example, when the air gap 1 increases, the air gap 2 decreases. Conversely, when the air gap 1 becomes smaller, the air gap 2 becomes larger.
Therefore, in the rotational displacement detection device of this embodiment, regardless of the constituent material and shape of the magnetic moving body 1 that is the member to be detected, it is resistant to misalignment and accurately detects a wide range of rotational displacement (wide angle range). It is possible to configure a linear magnetic circuit that can be used.
In this embodiment, a moving body (magnetic moving body 1) made of a magnetic body and moving in a curve in the moving direction is adopted as the moving body having a magnetic body. A moving body that has a non-magnetic body between the first and second magnetic bodies and moves in a curve in the moving direction may be employed.

[Modification]
In the present embodiment, the example in which the displacement detection device of the present invention is applied to a linear displacement detection device that detects the linear displacement amount (valve lift amount) of the control shaft of the variable valve mechanism of the internal combustion engine has been described. This displacement detection device may be applied to a rotational displacement detection device that detects the rotational displacement (throttle opening) of the throttle valve. Moreover, you may apply the displacement detection apparatus of this invention to the accelerator opening detection apparatus which detects the rotational displacement (accelerator opening) of an accelerator pedal. In these cases, rotational linear conversion means (link mechanism or the like) that converts the rotational displacement of the throttle valve (throttle opening) or the rotational displacement of the accelerator pedal (accelerator opening) of the internal combustion engine into the linear displacement of the magnetic moving body. Is provided.

In this embodiment, as the first and second divided portions, two first and second divided blocks 6 and 7 having a U-shaped cross section, or two first and second divided blocks 6 and 7 having an L-shaped cross section, Although the second divided blocks 6 and 7 are employed, two first and second divided blocks having a C-shaped cross section may be employed as the two first and second divided portions.
The two first and second magnets (magnets) 3 and 4 are more magnetic sensors than the two first and second magnetic bodies 31 and 32 of the magnetic body 10 or the magnetic body 10 made of a soft magnetic body or a magnetic body. If it is a side close to 2, it may be arranged anywhere on the magnetic fixed body (magnetic fixed block).

  In the present embodiment, the example in which the first and second magnets 3 and 4 which are permanent magnets are employed as the two first and second magnets has been described, but electromagnets are employed as the two first and second magnets. You may do it. In this case, the energization direction of the coil wound around the iron core (fixed magnetic body) constituting the electromagnet is set to the flow direction of the magnetic flux passing through the first magnetic circuit (first magnetic path) and the second magnetic circuit ( The flow direction of the magnetic flux passing through the second magnetic path) is adjusted to be opposite to each other.

It is the schematic diagram which showed the linear displacement detection apparatus (Example 1). (Example 1) which is the characteristic view which showed the stroke amount of the magnetic mobile body with respect to the magnetic flux amount which passes a magnetic sensor (Hall IC). (Example 2) which is the schematic diagram which showed the linear displacement detection apparatus. (Example 3) which is the schematic diagram which showed the linear displacement detection apparatus. (Example 4) which is the perspective view which showed the linear displacement detection apparatus. (A)-(c) is the schematic diagram which showed the state change of the linear displacement detection apparatus (Example 4). (Example 4) which is the characteristic view which showed the stroke amount of the moving body with respect to the magnetic flux amount which passes a magnetic sensor (Hall IC). (A) is the schematic diagram which showed the linear displacement detection apparatus, (b) is the perspective view which showed the magnetic moving body (Example 1). (A)-(c) is explanatory drawing which showed the manufacturing method of the moving body which has two 1st, 2nd magnetic bodies (Example 5). (Example 6) which is the perspective view which showed the linear displacement detection apparatus. (Example 7) which is the schematic diagram which showed the rotational displacement detection apparatus. (Example 7) which is the characteristic diagram which showed the rotational displacement amount (rotation angle) of the moving body with respect to the magnetic flux amount which passes a magnetic sensor (Hall IC). It is the block diagram which showed the linear displacement detection apparatus (conventional technique). It is the schematic diagram which showed the linear displacement detection apparatus (conventional technique). It is explanatory drawing which showed the magnet holding | maintenance part of the rotational displacement detection apparatus (conventional technique). It is explanatory drawing which showed the magnet holding | maintenance part of the rotational displacement detection apparatus (conventional technique).

Explanation of symbols

1 Magnetic moving body (moving body made of magnetic material, moving body made of soft magnetic material)
2 Magnetic sensor 3 First magnet (first magnet)
4 Second magnet (second magnet)
5 Sensor fixing block (magnetic fixed body)
6 1st division block (magnetic fixed body, 1st division part)
7 Second divided block (magnetic fixed body, second divided part)
DESCRIPTION OF SYMBOLS 9 Mobile body accommodation space 10 Mobile body which has a magnetic body (Moving body which has a nonmagnetic body between two 1st, 2nd magnetic bodies) 13 Opposite part of 1st division | segmentation block 14 Opposition part of 2nd division | segmentation block 31 1st 1 magnetic body 32 second magnetic body 33 non-magnetic body 41 opposing portion of the first divided block 42 opposing portion of the first divided block 43 opposing portion of the second divided block 44 opposing portion of the second divided block 61 of the first divided block Curved portion 62 Curved portion of second divided block G1 First air gap (air gap 1)
G2 Second air gap (air gap 2)
J1 1st magnetic circuit J2 2nd magnetic circuit

Claims (27)

(A) a magnetic moving body that moves linearly in the moving direction;
(B) It is arranged so as to face this magnetic moving body,
A magnetic sensor for detecting a change in magnetic flux passing through the magnetic moving body along with a linear movement of the magnetic moving body;
(C) The magnetic sensor is disposed on both sides in a direction perpendicular to the symmetry axis so as to have a symmetrical positional relationship with respect to the symmetry axis passing through the center of the magnetic sensor,
Two first and second magnets that emit magnetic flux toward the magnetic moving body and the magnetic sensor;
(D) holding and fixing the magnetic sensor and the two first and second magnets;
A first magnetic path connecting the magnetic moving body and the magnetic sensor via the first magnet, and a second magnetic path connecting the magnetic moving body and the magnetic sensor via the second magnet. In a displacement detection device comprising a magnetic fixed body that forms a magnetic path,
The two first and second magnets are magnetized so that the flow direction of magnetic flux passing through the first magnetic path and the flow direction of magnetic flux passing through the second magnetic path are opposite to each other,
The two first and second magnetic paths have only two first and second gaps that sandwich the magnetic moving body in a direction perpendicular to the moving direction of the magnetic moving body as an air gap. ,
The magnetic fixed body has two first and second divided portions respectively arranged on both sides in a direction perpendicular to the symmetry axis so as to be symmetric with respect to the symmetry axis. ,
The two first and second divided portions are opposed to the magnetic moving body with the second gap therebetween, and have opposing surfaces parallel to the moving direction of the magnetic moving body. A displacement detector characterized by the above. The displacement detection device according to claim 1,
The two first and second dividing portions are arranged so as to face each other with a moving body accommodating space for accommodating the magnetic moving body linearly movable in the moving direction. apparatus. In the displacement detection device according to claim 1 or 2,
The displacement detection device, wherein the two first and second division parts are arranged to face each other with at least the magnetic moving body and the magnetic sensor interposed therebetween. In the displacement detection device according to any one of claims 1 to 3,
The two first and second divided portions each have a facing portion facing the magnetic moving body with the second gap therebetween,
The opposing portions of the two first and second divided portions are extended in a direction parallel to the moving direction of the magnetic moving body, and are disposed so as to face each other with a predetermined gap therebetween. Displacement detecting device characterized by that. The displacement detection device according to claim 4,
The opposing portions of the two first and second divided portions are arranged on the opposite side to the magnetic sensor side with respect to the magnetic moving body so as to slightly overlap the magnetic moving body. Displacement detector. In the displacement detection device according to any one of claims 1 to 5,
The displacement detecting device, wherein the two first and second magnets are arranged on a magnetic sensor side with respect to an axis in a moving direction of the magnetic moving body. In the displacement detection apparatus according to any one of claims 1 to 6,
The magnetic sensor has a magnetosensitive surface facing the magnetic moving body with the first gap therebetween and parallel to the moving direction of the magnetic moving body. . In the displacement detection device according to any one of claims 1 to 7,
The magnetic moving body is opposed to the magnetic sensor with the first gap therebetween, a first end face parallel to the moving direction of the magnetic moving body, and the two first and second divided portions. A displacement detection device, characterized by having a second end face that faces each of the opposing faces across the second gap and is parallel to the moving direction of the magnetic moving body. The displacement detection device according to any one of claims 1 to 8,
The magnetic fixing body has a sensor fixing block on which the magnetic sensor is mounted on an axis of symmetry passing through the center of the magnetic sensor,
The sensor fixing block has a mounting surface for the first magnet and a mounting surface for the second magnet. The displacement detection apparatus according to claim 9,
The two first and second magnets are magnetized on the sensor fixing block so that the polarities of the magnetic pole surfaces on the side contacting each mounting surface of the sensor fixing block are opposite to each other. Displacement detection device. In the displacement detection apparatus according to any one of claims 1 to 10,
A displacement detection apparatus comprising two first and second magnetic circuits in which magnetic fluxes emitted from the two first and second magnets flow in opposite directions to each other. In the displacement detection apparatus according to any one of claims 1 to 11,
Each opposing surface of the two first and second divided portions is a plane,
The displacement detecting device according to claim 1, wherein the magnetic moving body is formed in a rectangular parallelepiped shape having a flat surface facing each facing surface of the two first and second divided portions. The displacement detection device according to claim 12,
The magnetic fixing body has a sensor fixing block on which the magnetic sensor is mounted on an axis of symmetry passing through the center of the magnetic sensor,
The sensor fixing block is opposed to the magnetic moving body with the first gap therebetween, and has a facing surface parallel to the moving direction of the magnetic moving body,
The displacement detection device according to claim 1, wherein an opposing surface of the sensor fixing block is a flat surface. In the displacement detection apparatus according to any one of claims 1 to 11,
The opposing surfaces of the two first and second divided portions are curved surfaces with a radius of curvature centered on the central axis of the magnetic moving body,
The displacement detecting device according to claim 1, wherein the magnetic moving body is formed in a cylindrical shape having a curved surface facing each of the opposing surfaces of the two first and second divided portions. The displacement detection device according to claim 14,
The magnetic fixing body has a sensor fixing block on which the magnetic sensor is mounted on an axis of symmetry passing through the center of the magnetic sensor,
The sensor fixing block is opposed to the magnetic moving body with the first gap therebetween, and has a facing surface parallel to the moving direction of the magnetic moving body,
The displacement detection device according to claim 1, wherein the opposing surface of the sensor fixing block is a curved surface having a radius of curvature centering on a central axis of the magnetic moving body. (A) a moving body having a magnetic body and linearly moving in the moving direction;
(B) It is arranged to face this moving body,
A magnetic sensor for detecting a change in magnetic flux passing through the magnetic body of the moving body along with the linear movement of the moving body;
(C) The magnetic sensor is disposed on both sides in a direction perpendicular to the symmetry axis so as to have a symmetrical positional relationship with respect to the symmetry axis passing through the center of the magnetic sensor,
Two first and second magnets that emit magnetic flux toward the magnetic body of the moving body and the magnetic sensor;
(D) holding and fixing the magnetic sensor and the two first and second magnets;
A first magnetic path connecting the magnetic body of the moving body and the magnetic sensor via the first magnet, and between the magnetic body of the moving body and the magnetic sensor via the second magnet. In a displacement detection device comprising a magnetic fixed body forming a second magnetic path connecting
The two first and second magnets are magnetized so that the flow direction of magnetic flux passing through the first magnetic path and the flow direction of magnetic flux passing through the second magnetic path are opposite to each other,
The two first and second magnetic paths have only two first and second gaps that sandwich the moving body in a direction perpendicular to the moving direction of the moving body as an air gap,
The magnetic fixed body has two first and second divided portions respectively arranged on both sides in a direction perpendicular to the symmetry axis so as to be symmetric with respect to the symmetry axis. ,
The two first and second dividing portions are opposed to the magnetic body of the moving body with the second gap therebetween, and each have a facing surface parallel to the moving direction of the moving body. A displacement detector characterized by the above. The displacement detection device according to claim 16,
Each opposing surface of the two first and second divided portions is a plane,
The magnetic body of the moving body is a rectangular parallelepiped having a plane parallel to the moving direction of the moving body, facing the opposing surfaces of the two first and second divided portions with the second gap therebetween. A displacement detection device characterized by being formed into a shape. The displacement detection device according to claim 17,
The magnetic fixing body has a sensor fixing block on which the magnetic sensor is mounted on an axis of symmetry passing through the center of the magnetic sensor,
The sensor fixing block is opposed to the magnetic body of the moving body across the first gap, and has a facing surface parallel to the moving direction of the moving body,
The displacement detection device according to claim 1, wherein an opposing surface of the sensor fixing block is a flat surface. The displacement detection device according to claim 16,
The opposing surfaces of the two first and second divided portions are curved surfaces with a radius of curvature centered on the central axis of the magnetic body of the moving body,
The magnetic body of the moving body is a cylinder having a curved surface that is opposed to the opposing surfaces of the two first and second divided portions with the second gap therebetween and is parallel to the moving direction of the moving body. A displacement detection device characterized by being formed into a shape. The displacement detection device according to claim 19,
The magnetic fixing body has a sensor fixing block on which the magnetic sensor is mounted on an axis of symmetry passing through the center of the magnetic sensor,
The sensor fixing block is opposed to the magnetic body of the moving body across the first gap, and has a facing surface parallel to the moving direction of the moving body,
2. The displacement detecting device according to claim 1, wherein the opposing surface of the sensor fixing block is a curved surface having a radius of curvature centering on a central axis of the magnetic body of the moving body. The displacement detection device according to any one of claims 16 to 20,
The magnetic body of the moving body includes two first and second magnetic bodies that face each other facing surfaces of the two first and second divided portions with the second gap therebetween.
The displacement detection device, wherein the moving body has a non-magnetic body between the two first and second magnetic bodies. The displacement detection device according to any one of claims 16 to 21,
The magnetic body of the moving body is opposed to the magnetic sensor with the first gap therebetween and is parallel to the moving direction of the moving body, and the two first and second divided portions. Displacement detecting device characterized by having a second end face that faces each of the opposing faces across the second gap and is parallel to the moving direction of the moving body. (A) a moving body having a magnetic body and moving in a curve in the moving direction;
(B) It is arranged to face this moving body,
A magnetic sensor for detecting a change in magnetic flux passing through the magnetic body of the moving body as the moving body moves along a curve;
(C) arranged on both sides in a direction perpendicular to the symmetry axis passing through the center of the magnetic sensor,
Two first and second magnets that emit magnetic flux toward the magnetic body of the moving body and the magnetic sensor;
(D) holding and fixing the magnetic sensor and the two first and second magnets;
A first magnetic path connecting the magnetic body of the moving body and the magnetic sensor via the first magnet, and between the magnetic body of the moving body and the magnetic sensor via the second magnet. In a displacement detection device comprising a magnetic fixed body forming a second magnetic path connecting
The two first and second magnets are magnetized so that the flow direction of magnetic flux passing through the first magnetic path and the flow direction of magnetic flux passing through the second magnetic path are opposite to each other,
The two first and second magnetic paths have only two first and second gaps that sandwich the moving body in a direction perpendicular to the moving direction of the moving body as an air gap,
The magnetic stationary body has two first and second divided portions respectively disposed on both sides in a direction perpendicular to the symmetry axis.
The two first and second divided portions oppose the magnetic body of the moving body with the second gap therebetween, and each has a facing surface that is curved along the moving direction of the moving body. A displacement detector characterized by the above. The displacement detection device according to claim 23,
The opposing surfaces of the two first and second divided portions are concave curved surfaces with a radius of curvature centering around the center of the magnetic sensor,
The magnetic body of the moving body has a convex curved surface that faces the opposing surfaces of the two first and second divided portions with the second gap therebetween and is curved along the moving direction of the moving body. A displacement detection device characterized by being formed in a partial cylindrical shape. The displacement detection device according to claim 24,
The magnetic fixing body has a sensor fixing block on which the magnetic sensor is mounted on an axis of symmetry passing through the center of the magnetic sensor,
The sensor fixing block is opposed to the magnetic body of the moving body across the first gap, and has a facing surface curved along the moving direction of the moving body,
2. A displacement detecting device according to claim 1, wherein the opposing surface of the sensor fixing block is a convex curved surface having a radius of curvature centering around a central portion of the magnetic sensor. In the displacement detection apparatus according to any one of claims 23 to 25,
The magnetic body of the moving body is opposed to the magnetic sensor with the first gap therebetween, and has a concave curved surface that is curved along the moving direction of the moving body, and the two first and second divided portions. A displacement detection device characterized by having a convex curved surface that faces each opposing surface with the second gap therebetween and is curved along the moving direction of the movable body. In the displacement detection device according to any one of claims 23 to 26,
The displacement detection device according to claim 1, wherein the magnetic body of the moving body is formed in a partial cylindrical shape extending in an arc shape along a moving direction of the moving body.

Images