JPH0337512A - Detecting apparatus - Google Patents

Abstract

PURPOSE:To realize an apparatus which can detect rotating speeds, slant angles, vibration and the like quickly by supporting a magnetized movable body in a container through a magnetic fluid so that the movable body is rotated freely, and detecting the relative displacement of the container and the movable body with a detector. CONSTITUTION:Both sides of a movable body 3 are magnetized by two polarities N and S. The movable body 3 is supported by a magnetic fluid which is attached to the surrounding part of the movable body in a containing part 102 of a container 1 comprising nonmagnetic material so that the movable body 3 is rotated freely. A detector 4 comprising a magnetism sensitive element is attached to the outside of the container 1. When the container 1 is rotated or inclined under this state, the movable body 3 keeps the stationary state. Relative displacement of rotation are generated between the movable body 3 and the container 1. The displacement is detected from the output of the magnetism sensitive element. Therefore, the minute displacement can be detected positively.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a detection device, and includes a container, a magnetic fluid, a movable body, and a detector, and the movable body has at least two magnetic poles facing each other. The two magnetic poles are located on both sides of the container, and the magnetic fluid is attached around the two magnetic poles to allow relative rotational displacement between the two magnetic poles and the container. By supporting the container and detecting the relative rotational displacement of the movable body with a detector, it can be widely applied to detection of rotation angle, tilt angle, acceleration J vibration, magnetism, etc. The present invention provides a detection device that has low frictional resistance against relative rotational displacement, can continuously and reliably detect even minute displacements, is structurally robust, and is easy to handle.

<Prior Art> As a conventional technique, a permanent magnet is supported by a magnetic fluid and housed in a container, and the relative rotational displacement between the container and the permanent magnet is detected by a magnetic sensing element. For example, Utility Model Publication No. 63-141415, Japanese Patent Application Publication No. 63-3177
No. 12), and orientation sensors (e.g. Utility Model No. 63-1018)
No. 10) etc. are known.

<Problems to be Solved by the Invention> However, the above-mentioned inclination angle detection device uses a permanent magnet that is magnetized in the vertical direction with respect to the horizontal plane,
This permanent magnet is supported so as to float in a magnetic fluid at the bottom of a container that has an inclination angle to be detected, and when the horizontal angle changes to a position that cancels the inclination angle set on the bottom, the permanent magnet Since the configuration uses movement in the horizontal direction to detect the inclination angle, if the inclination angle changes continuously, the continuous change cannot be detected.

Furthermore, the orientation sensor disclosed in Japanese Utility Model Application Publication No. 101810/1981 is configured to detect an orientation from the direction of the magnetic field of the permanent magnet when the permanent magnet rotates in plane around an axis substantially perpendicular to the horizontal plane due to the earth's magnetism. , it cannot detect tilt angles, rotation angles, accelerations, vibrations, etc.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, to be widely applicable to detection of rotation angles, tilt angles, accelerations, vibrations, magnetism, etc., and to detect relative rotation between a container and a movable body. It is an object of the present invention to provide a detection device that has low frictional resistance against displacement, can continuously and reliably detect even minute displacements, is structurally robust, and is easy to handle.

<Means for Solving the Problems> In order to solve the above-mentioned problems, the present invention provides a detection device including a container, a magnetic fluid, a movable body, and a detector, wherein the movable body has at least two It has magnetic poles on opposite sides, and the magnetic fluid attached around the two magnetic poles allows the two magnetic poles to be positioned on both sides in the horizontal direction and allow relative rotational displacement between the two magnetic poles and the container. like,
It is characterized in that it is supported inside the container, and the relative rotational displacement of the container and the movable body is detected by the detector.

The movable body has at least two magnetic poles on opposing sides, and the magnetic fluid that adheres around the two magnetic poles causes the two magnetic poles to be located on both sides in the horizontal direction, and the movable body has at least two magnetic poles on opposite sides. The movable body is supported inside the container to allow rotational displacement, so that when the container is rotated about a horizontal axis or tilted, the movable body remains in its position under the action of gravity; A relative rotational displacement occurs between the movable body and the container. In the present invention, the relative rotational displacement of the container and the movable body at this time is detected by a detector.

The relative rotational displacement between the movable body and the container is caused by a rotation angle, a tilt angle, vibration, or the like. Therefore, according to the present invention, a detection device capable of detecting rotation angle, tilt angle, vibration, etc. can be realized.

Relative rotational displacement between the container and the movable body is similarly caused by acceleration or an external magnetic field to the movable body. Therefore, it can also be used as a detection device for detecting acceleration and external magnetic fields.

The relative rotational displacement between the container and the movable body is continuous. Therefore, a continuous detection device can be easily realized.

Moreover, since the movable body rotates while being guided by the inner wall surface of the container via the magnetic fluid attached to the magnetic poles, the frictional resistance against relative rotational displacement between the container and the movable body is small.
Even minute displacements can be detected quickly and reliably.

Furthermore, since it is composed of a container, a magnetic fluid housed in the container, and a movable body that has a magnetic pole and is rotatably supported within the container by the magnetic fluid attached to the magnetic pole, it is structurally robust. , a detection device that is easy to handle can be obtained.

<Example> FIG. 1 is a perspective view showing the basic configuration of a detection device according to the present invention. In the figure, 1 is a container, 2 is a magnetic fluid, and 3 is a container.
4 indicates a movable body, and 4 indicates a detector.

The container 1 is made of a non-magnetic material and has a storage section 101 in which the magnetic fluid 2 and the movable body 3 are stored. The inner wall surface 102 of the storage section 101 has a circular shape. Both sides of the storage section 101 in the axial direction are open, but in reality,
A lid is required to prevent evaporation of the magnetic fluid 2.

The composition of magnetic fluid 2 is well known. For example, it has a composition in which a magnetic metal such as cobalt, iron, or nickel is dispersed in a low viscosity liquid such as kerosene or water, and a surfactant is added. The volume of the magnetic fluid 2 is smaller than the volume of the storage section 101 of the container 1 .

The movable body 3 has at least two magnetic poles N and S. The magnetic poles N, S can be constituted by permanent magnets or electromagnets. The magnetic poles N and S are arranged on opposite sides of the movable body 3, and the illustrated movable body 3 is a magnet with a circular outer periphery, and has the magnetic poles N and S on both sides in the diametrical direction. There is.

The movable body 3 is arranged so that the two magnetic poles N and S are located on both sides in the horizontal direction by the magnetic fluid 2 attached around the two magnetic poles N and S, allowing relative rotational displacement between the two magnetic poles N and S and the container 1. ,
It is supported inside the container 1.

Detector 4 detects relative rotational displacement of container 1 and movable body 3. In the illustration, the detector 4 is composed of a magnetically sensitive element and is attached to the outer wall surface of the container 1 inside the body. Since the purpose of the detector 4 is to detect the relative rotational displacement of the container 1 and the movable body 3, other sensors such as an optical sensor can be used in addition to the magnetic sensing element depending on how it is configured. . Furthermore, even when using magnetically sensitive elements,
In addition to sensors capable of continuous detection such as Hall elements and magnetoresistive elements, on/off type sensors such as a reed switch can also be used.

As described above, the magnetic fluid 2 is stored in the storage section 101 of the container 2.
It is smaller in volume than the volume of the magnetic poles N and S, and is concentrated on the poles N and S, and the amount of adhesion decreases in the middle part between the two magnetic poles N and S. Furthermore, the movable body 3 allows the two magnetic poles N and S to be positioned on both sides in the horizontal direction due to the magnetic fluid 2 attached around the two magnetic poles N and S, allowing relative rotational displacement between the two magnetic poles N and S and the container 1. It is supported inside the container 1 as shown in FIG.

In this state, if the container 1 rotates or tilts, the movable body 3 remains stationary under the action of gravity.
A relative rotational displacement occurs between the movable body 3 and the container 1. This relative rotational displacement is detected by the detector 4. Since the rotation and inclination of the container 1 change depending on the rotation angle, inclination angle, vibration, etc., it can be used as a detection device for detecting the rotation angle, inclination angle, or vibration.

In addition, since the movable body 3 rotates while being guided by the inner wall surface 102 of the container 1 via the magnetic fluid 2 attached to the magnetic poles N and S, the relative rotational displacement between the container 1 and the movable body 3 is It has low frictional resistance, excellent coordination, and can reliably detect minute displacements.

Furthermore, the relative rotational displacement between the container 1 and the movable body 3 is similarly caused by rotational displacement of the movable body 3 due to acceleration or an external magnetic field. Therefore, it can also be used as a detection device for detecting acceleration and external magnetic fields.

Furthermore, the relative rotational displacement between the container 1 and the movable body 3 is continuous. Therefore, by using a sensor capable of continuous detection, such as a Hall element or a magnetoresistive element, as the detector 4, a detection device that continuously detects rotational displacement can be easily realized.

Next, the relationship between relative rotational displacement and detector output will be described with reference to FIG. 2, taking as an example a case where a continuous detection sensor such as a Hall element or a magnetoresistive element is used as the detector 4. In FIG. 2, the horizontal axis represents the rotation angle and the relative rotational position of the movable body 3 and the container 1 at that time, and the vertical axis represents the detector output. The relative rotational position of the movable body 3 and the container 1 is indicated by the position of the detector 4.

First, if the position where the detector 4 is located facing the S magnetic pole of the movable body 3 is defined as a reference position of zero rotational displacement, the detection output becomes minimum at this reference position. Then, 4 in the direction of arrow a.
Maximum at 5 degrees rotated position, minimum at 90 degrees rotated position,
It changes in a curve that reaches a maximum at a position rotated by 135 degrees and a minimum at a position rotated by 180 degrees. Therefore, the rotation angle can be detected from the detector output.

Next, various embodiments of the present invention will be described.

3 to 9 show modified examples of the movable body 3. FIG. The movable body 3 shown in FIG. 3 has a structure in which magnets 32 and 33 are arranged on both sides in the diametrical direction of a base body 31 made of a non-magnetic material or a magnetic material. This example suggests that it is not necessarily necessary to configure the entire movable body 3 with magnets.

In the embodiment shown in FIG. 4, the movable body 3 has magnetic fields 'Fi1' on both ends.
It is composed of magnets with N and S magnets. This example is
This shows that the outer shape of the movable body 3 does not necessarily have to be circular.

FIG. 5 shows an example in which the movable body 3 has a plurality of magnetic poles N and S on its outer periphery. Each magnet, iN, and S are arranged so that a magnetic neutral line is generated in a direction perpendicular to the direction in which the magnetic pole N-3 is arranged at an intermediate portion thereof. The magnetic pole N%S can be formed by magnetizing the outer periphery of the movable body 3 made of a magnetic material, or by attaching a magnet to the movable body 3 made of a magnetic or non-magnetic material.

FIG. 6 shows magnets 32.3 on both sides of the base body 31 in the diametrical direction.
The arrangement of the magnets 32 and 33 is similar to the case shown in FIG. 3, but the difference is that the relationship between the magnetic poles of the magnets 32 and 33 is reversed.

In the embodiment shown in FIG. 7, the magnetic poles arranged at opposite ends are composed of N and S pairs, and a plurality of N and S pairs are provided. The magnetic poles N and S can be formed by magnetizing the outer periphery of the movable body 3 made of a magnetic material, or by attaching magnets to the movable body 3 made of a magnetic or non-magnetic material.

In the embodiment shown in FIG. 8, the magnetic poles arranged at opposite ends are composed of a pair of N and S. In this embodiment as well, the magnetic poles N and S can be formed by magnetizing the outer periphery of the movable body 3 made of a magnetic material, or by attaching magnets to the movable body 3 made of a magnetic or non-magnetic material.

In the case of the embodiments shown in FIGS. 5 to 8, the external magnetic field H such as earth's magnetism
A rotational force in the direction of arrow C1 between L and magnetic poles N and S,
Since a rotational force in the direction of arrow C2 opposite to this is generated, it is possible to realize a detection device for detecting rotation angle, tilt angle, vibration, or acceleration that is less susceptible to the influence of external magnetic field Hl.

FIG. 9 shows another example of a detection device that is less susceptible to the influence of the external magnetic field Hl. The movable body 3 includes at least two movable bodies 3A and 3B, and the two movable bodies 3A and 3B are coaxially coupled with the polarities of the magnetic poles N and S reversed. In the case of this embodiment, the magnet 3A is generated by an external magnetic field Hl such as earth's magnetism.
The rotational direction C+ of the magnet 3B and the rotational direction C2 of the magnet 3B are opposite to each other. Therefore, it becomes less susceptible to the influence of external magnetic fields such as earth's magnetism.

FIG. 10 shows yet another embodiment of the detection device according to the present invention. This embodiment shows a case where the relative rotational displacement between the container 1 and the movable body 3 is detected by a detector 4 provided integrally with the movable body 3. The detector 4 is integrally coupled to the movable body 3 by an arm 41. A detection element 42 is attached to the arm 41, and a target 43 attached to the container 1 is read by this detection element 42. Target 43 is determined by the type of detection element 42. For example, if the sensing element 42 is a magnetically sensitive element, such as a magnetic strip, magnetic strip, or magnetic recording medium, and if it is an optical sensor, it is a light reflector, a light transmissive, or an optical recording medium.

FIG. 11 shows another embodiment of the detection device according to the present invention. In this embodiment, the container 1 has two inner wall surfaces 102 with different radii, and the movable body 3 is supported between the inner wall surfaces 102-102.

Therefore, the movable body 3 rotates with a rotation center different from the axis of the container 1.

FIGS. 12 and 13 show specific embodiments of the detection device according to the present invention. The container 1 has a cylindrical storage section 101
It is formed into a cylindrical shape with a lid 1 on both axial ends.
03.104. Ring-shaped protrusions 105 to 108 are provided on the inner wall surface 102 and the inner wall surfaces of the lids 103 and 104 that constitute the storage section 101 of the container 1. These protrusions 105-108 serve to reduce frictional resistance.

The movable body 3 is made of a ring-shaped permanent magnet, and is magnetized so that magnetic poles N and S are formed on both sides in the diametrical direction. 14 and 15 are diagrams showing the magnetized state of the movable body 3. FIG. With the magnetic neutral line A taken in the diametrical direction as the boundary,
One outer peripheral surface is the area controlled by the magnetic pole N, the inner peripheral surface of the inner diameter hole is the area of the magnetic pole S, the other outer peripheral surface is the area of the magnetic pole S, and the inner wall surface of the inner diameter hole is the area of the magnetic pole N. It is magnetized as follows. The strength of the magnetic field of the movable body 3 is the magnetic neutral line A
Since the magnetic fluid 2 is strongest on the X-axis perpendicular to the magnetic field, the largest amount of magnetic fluid 2 adheres on the X-axis, and the amount of S attached decreases as it moves toward the magnetic neutral line A.

FIG. 16 shows a sectional view of another embodiment of the detection device according to the present invention. This embodiment is a specific example of the detection device shown in FIG. are reversed and connected on the same axis.

<Effects of the Invention> As described above, according to the present invention, the following effects can be obtained.

(a) The movable body has at least two magnetic poles on opposite sides, and a magnetic fluid attached around the two magnetic poles causes the two magnetic poles to be located on both sides in the horizontal direction, and the movable body has at least two magnetic poles on opposite sides. The movable body is supported inside the container so as to allow rotational displacement, and the relative rotational displacement of the container and the movable body is detected by a detector, so the rotation angle,
The present invention provides a detection device capable of detecting inclination angle, vibration, acceleration, external magnetic field, etc. with a wide range of uses.

(b) the relative rotational displacement between the container and the movable body is continuous;
A detection device capable of continuously detecting rotation angle, tilt angle, vibration, acceleration, external magnetic field, etc. is provided.

(C) Since the movable body rotates while being guided by the inner wall surface of the container via the magnetic fluid attached to the magnetic poles, the frictional resistance against relative rotational displacement between the container and the movable body is small, and minute displacements can be made quickly. It is possible to provide a detection device that can reliably detect.

(d) It is structurally robust because it is composed of a container, a magnetic fluid contained in the container, and a movable body that has a magnetic pole and is rotatably supported within the container by the magnetic fluid attached to the magnetic pole. Therefore, it is possible to provide a detection device that is easy to handle.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the basic configuration of the detection device according to the present invention, FIG. 2 is a diagram showing the relationship between the relative rotational displacement of the movable body and the container and the detector output, and FIGS. 3 to 9 10 is a perspective view showing another embodiment of the detection device according to the present invention; FIG. 11 is a diagram showing still another embodiment of the detection device according to the present invention. , FIG. 12 is a plan sectional view of a specific embodiment of the detection device according to the present invention, FIG. 13 is a front sectional view of the same, and FIG. 14 is a diagram showing the magnetization of the movable body shown in FIGS. 12 and 13. FIG. 15 is a perspective view showing the state, FIG. 15 is a sectional view thereof, and FIG. 16 is a plan sectional view of another embodiment of the detection device according to the present invention. 1... Container 2... Magnetic fluid 3... Movable body 4... Detector JP-A-3 37512 (9) Fig. 13 Fig. 14 JP-A-3 37512 (10) 6 Fig. 1 "Silicon" ox handicap

Claims (1)

[Claims] (1) A detection device including a container, a magnetic fluid, a movable body, and a detector, wherein the movable body has at least two magnetic poles on opposing sides, and is attached around the magnetic poles. at least the two magnetic poles are located on both sides in the horizontal direction and are supported inside the container so as to allow relative rotational displacement between the container and the movable magnetic fluid; A detection device characterized in that the relative rotational displacement of a body is detected by the detector.