JPH09257514A - Moving condition detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently concentrate a magnetic flux on a magnetic flux sensing element, and increase a maximum detecting distance at which a moving condition of a detection object moving body can be detected by putting and arranging a cover-shaped yoke having an opening corresponding to the detection object moving body on a magnetic flux generating means. SOLUTION: A spacer 9 is arranged on a side surface of a columnar magnet 4, and a cover-shaped yoke 8 is put and arranged from above it, and when an opening part of the yoke 8 is opposed to a detection object moving body 7, a magnetic flux generated from the magnet 4 is restrained from divergence to a peripheral area, and efficiently flows to a side surface part from a top surface part of the yoke 8, and proceeds to the opening part. As a result, an effect of actively concentrating the magnetic flux from the magnet 4 on electromagnetic sensing elements in a detecting element 3 is exhibited. A defective part smaller than an opening part on the other end is bored in a position dislocated from the center of the top part of the yoke 8, and when a surface of the magnet 4 is slidingly moved in rotation, a magnetic field imparted to the juxtaposed two electromagnetic sensing elements can be adjusted, and a maximum detecting distance D can be enlarged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a rack, a gear in a rack and pinion mechanism, and a moving state of a moving body such as a gear and a magnet of a multi-pole magnetized, which moves linearly or rotationally, for example, moving distance and moving speed. The present invention relates to a moving state detection device that detects

[0002]

2. Description of the Related Art FIG. 2 shows a conventional moving state detecting device (for example, this type of technique is disclosed in Japanese Patent Application Laid-Open No. 6-123638).
FIG. The moving state detecting device shown in FIG. 1 includes a cylindrical case 1 and a lid member 2 which is arranged at a lower end portion of the case 1 and whose upper and lower surfaces are flat.
12, a detection element 3 mounted on the inner surface side of the top surface of the lid member 2, a cylindrical magnet 4 for giving a magnetic field to the detection element 3, and an upper side of the magnet 4 as shown in FIG. A circular yoke 5 is laminated and arranged, and further, a detecting element 3 in the case 1, a magnet 4 and a filler 6 for fixing and holding the yoke 5, and other elements are arranged so as to face the detecting element 3. It is composed of the detected moving body 7.
In addition, the detection element 3 has two magnetic flux sensing elements, for example, magnetoelectric conversion elements a and b arranged side by side in the arrangement direction of the convex portion and the concave portion of the moving body 7 to be detected. Processing means for processing the output and outputting it as an electric signal is included.

As shown in FIG. 12, the semi-circular yoke 5 has two magnetism conversion elements arranged in parallel by rotating and sliding on the surface of the magnet with the center of the magnet as a fulcrum.
The magnetic flux applied to a and b is adjusted so that the maximum detection distance is reached. Here, the maximum detection distance is as shown in FIG.
Of the distances between the edge of the detected moving body 7 and the top surface of the lid member 2 indicated by D, the maximum distance at which the moving state of the detected moving body 7 can be detected. Further, except for the magnet 4, the semicircular yoke 5, and the moving body 7 to be detected, it is basically made of a non-magnetic material.

The moving state detecting device having the above-described structure drives the moving body 7 to be detected in the X direction of the arrow by the parts which are required to detect movement, and two moving objects are arranged in parallel according to the uneven shape of the moving body 7 to be detected. A change occurs in the magnetic flux applied to the installed magnetoelectric conversion elements a and b. As a result, a pulse wave is obtained from the detection element 3. Further, the moving state of the moving body 7 to be detected can be detected by counting the number of pulses of this pulse wave per unit time.

[0005]

In the conventional moving state detecting device as described above, the magnet 4 for applying the magnetic field to the detecting element 3 and the semicircular yoke 5 above the magnet 4 are laminated and arranged. Since the magnetic flux from the magnet 4 diverges to the peripheral region, there is a problem that the magnetic flux from the magnet 4 cannot be efficiently concentrated on the magnetic flux sensing element. Therefore,
The present invention has been made to solve the problems as exemplified above, and efficiently concentrates the magnetic flux from the magnetic flux generating means on the magnetic flux sensing element, and the magnetic flux passing through the two magnetic flux sensing elements arranged in parallel. Is adjusted to increase the maximum detection distance at which the moving state of the detected moving body can be detected.

[0006]

[Means for Solving the Problems]

(Structure 1) A detected moving body which is made of a magnetic material and which is provided with at least one convex portion and at least one concave portion and moves in the arrangement direction of the convex portion and the concave portion, and the detected movable body. A magnetic flux sensing element arranged correspondingly, processing means for processing an output of the magnetic flux sensing element to generate an electric signal representing a moving state of the detected moving body, the detected moving body and the magnetic flux. What is claimed is: 1. A moving state detecting device comprising: a magnetic flux generating means arranged to form a magnetic flux passing through a sensing element; and a yoke, wherein the yoke is provided on the magnetic flux generating means so as to concentrate the magnetic flux. The moving state detecting device is a lid-shaped yoke having an opening corresponding to the detected moving body.

(Description 1) FIG. 1 is a sectional view of an embodiment showing a moving state detecting device of the present invention. As shown in FIG.
The magnetic flux generating means, for example, a spacer 9 is provided on the side surface of the magnet 4, the lid-shaped yoke 8 is covered from above the spacer 9, and the opening thereof faces the moving body 7 to be detected. Positively detecting the magnetic flux of 3
There is an effect of concentrating on the magnetic flux sensing element inside.

(Structure 2) A detected moving body, which is made of a magnetic material, has at least one convex portion and at least one concave portion, and moves in the arrangement direction of the convex portion and the concave portion, and the detected movement. Two magnetic flux sensing elements arranged in the array direction so as to correspond to the body, and processing means for processing the output of the magnetic flux sensing elements to generate an electric signal representing the movement state of the moving body to be detected. A moving state detecting device comprising a yoke and a magnetic flux generating means provided to form a magnetic flux passing through the moving body to be detected and the magnetic flux sensing element, wherein the yoke concentrates the magnetic flux. A moving state detecting device, which is a lid-like yoke that is covered with the magnetic flux generating means and has an opening corresponding to the detected moving body.

(Explanation 2) In the detection element 3 shown in FIG. 1, when two magnetic flux sensing elements are arranged side by side in the arrangement direction of the convex portion and the concave portion of the moving body 7 to be detected, the magnetic flux is similarly generated. A magnetic flux from the magnetic flux generating means is provided by arranging a spacer 9 on a side surface of the magnet 4, covering the lid-shaped yoke 8 from above, and having its opening facing the detected moving body 7. Is positively concentrated on the magnetic flux sensing element in the detection element 3.

(Structure 3) In the moving state detecting device according to structure 2, in the lid-shaped yoke, a defect portion smaller than the opening portion is formed at a position off the center of the top surface portion, and the detected object is detected. A moving state detecting device, which is operably provided so as to adjust a magnetic flux passing through a moving body and the magnetic flux sensing element.

(Explanation 3) A lid-like yoke 8 having a defect portion smaller than the size of the opening at the other end is provided at a position off the center of the top surface portion as shown in FIG. Then, the magnetic field applied to the two magnetic flux sensing elements arranged side by side can be adjusted by rotating and sliding the surface of the magnet 4 from above with the center of the covering magnet 4 as a fulcrum, and the maximum detection distance is obtained. Can be adjusted in position.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific examples of the present invention will be described in detail below with reference to the drawings. In the following description, the first specific example corresponds to the configuration 1, the second specific example corresponds to the configuration 2, and the third specific example corresponds to the configuration 3.

(First Specific Example) FIG. 1 is a sectional view showing an embodiment of a moving state detecting device of the present invention. The moving state detecting device shown in the same figure has a cylindrical case 1 and this case 1
A lid member 2 which is arranged at the lower end of the
The detection element 3 mounted on the inner surface side of the top surface of the lid member 2.
And a cylindrical magnet 4 for applying a magnetic field to the detection element 3, and a lid-shaped yoke 8 on the upper side of the magnet 4, and further, the detection element 3, the magnet 4 and the lid-shaped yoke 8 in the case are fixed. The filler 6 to be held and, in addition, the moving body 7 to be detected arranged so as to face the detection element 3.
And is composed of Here, the detection element 3 includes therein a magnetic flux sensing element, for example, a magnetoelectric conversion element, and appropriately includes processing means for processing the output of the magnetoelectric conversion element and outputting it as an electric signal.

Of these, by covering the lid-shaped yoke 8 from the upper side of the columnar magnet 4, the magnetic flux generated from the columnar magnet 4 suppresses the divergence of the magnetic flux to the peripheral region, and the lid-shaped yoke 8 is efficiently performed. From the top to the side of
Then, it goes toward the opening of the lid-shaped yoke 8. As a result, there is an effect that the magnetic flux from the cylindrical magnet 4 is positively concentrated on the magnetoelectric conversion element in the detection element.

Next, in the apparatus of this embodiment shown in FIG. 1, the lid-like yoke 8 can positively concentrate the magnetic flux from the magnet 4 on the magnetoelectric conversion element in the detection element based on the embodiment. explain. First, the moving body 7 to be detected is driven in the X direction indicated by the arrow by a component that requires movement detection. A magnetic flux corresponding to the uneven shape of the moving body to be detected 7 is applied to the magnetoelectric conversion element. Further, the magnetoelectric conversion element outputs a voltage corresponding to the applied magnetic flux, and the voltage output from the magnetoelectric conversion element is amplified by the processing means also incorporated in the detection element 3 and output as the voltage V0. To be done. FIG.
The results of comparing the voltage V0 between the case where the conventional semi-circular yoke 5 shown in FIG. 12 is used and the case where the lid-shaped yoke 8 shown in FIG. 3 is used are shown. The larger the amplitude of the voltage V0, the larger the magnetic flux applied to the magnetic flux sensing element. It can be seen from FIG. 4 that when the lid-shaped yoke is used, the magnetic flux generated from the magnet 4 is positively concentrated on the magnetic flux sensing element as compared with the case where the semi-circular yoke is used.

(Second Specific Example) Generally, the output sensitivity of the magnetoelectric conversion element in the detection element 3 to the magnetic flux has a large temperature dependency, and therefore two are often arranged in parallel to cancel each other. . Therefore, even when two magnetoelectric conversion elements are arranged in the detection element 3 side by side in the arrangement direction of the convex portion and the concave portion of the moving body 7 to be detected, the magnetic flux generating means, for example, the magnetic flux of the magnet 4 is also positively activated. First, it will be described based on an embodiment that the detection element 3 can be concentrated on the magnetoelectric conversion element.

First, the detected moving body 7 is driven in the direction of the arrow X by a component that requires movement detection. 2 in detection element 3
A magnetic flux corresponding to the uneven shape of the moving body 7 to be detected is applied to each of the magnetoelectric conversion elements a and b. Also, as shown in FIG.
The magnetoelectric conversion elements a and b output voltages Va and Vb according to the applied magnetic flux. After that, each magnetoelectric conversion element
The voltages Va and Vb output from a and b are the difference (ΔV) between the voltages Va and Vb output from the magnetoelectric conversion elements a and b by the processing means A shown in FIG. = Va-Vb) is output. FIG. 13 shows a comparison result of the amplitude values of the differential voltage (ΔV = Va−Vb) when the conventional semi-circular yoke shown in FIG. 12 is used and when the lid yoke 8 shown in FIG. 3 is used. Show. The larger the amplitude value of the difference voltage (ΔV = Va−Vb), the larger the magnetic flux applied to the magnetoelectric conversion element. The detection distance in FIG. 13 indicates the distance between the edge of the tooth of the moving body to be detected 7 shown in FIGS. 1 and D and the top surface portion of the lid member 2. From FIG. 13, when the lid-shaped yoke 8 is used, since the magnetic flux generated from the magnet 4 is positively concentrated on the magnetoelectric conversion element, the differential voltage (ΔV = Va-V
It can be seen that the amplitude value in b) is large.

(Third Concrete Example) Next, in the apparatus of this embodiment shown in FIG. 1 as well, since the two magnetoelectric conversion elements in the detection element 3 have variations in output sensitivity with respect to magnetic flux, It is necessary to adjust the magnetic field applied to the side-by-side magnetoelectric conversion elements so that the maximum detection distance is reached. Therefore, as shown in FIG. 3, a lid-shaped yoke 8 having a defect smaller than the size of the opening at the other end at a position deviated from the center of the top surface is rotationally slid on the surface of the magnet 4 with the center of the magnet 4 as a fulcrum. An example in which the lid-shaped yoke can be adjusted to a position where the maximum detection distance can be obtained by adjusting the magnetic fields applied to the two magnetoelectric conversion elements arranged in parallel will be described.

First, the differential voltage (ΔV = Va-Vb) between the voltages Va and Vb output from the magnetoelectric conversion elements a and b described in the second specific example is used, and then the processing means B shown in FIG. As shown in FIG. 7, the output level of the electric signal becomes L level when it becomes equal to or higher than the constant upper threshold value V1 and becomes H level when it becomes equal to or lower than the constant lower threshold value V2. It is output as a pulse wave.

The duty ratio of the pulse wave is changed by rotating and sliding the lid-shaped yoke 8 shown in FIG. 3 on the surface of the magnet 4 with the center of the magnet 4 as a fulcrum. FIG. 9 is a characteristic diagram showing the relationship between the rotation angle θ of the lid-shaped 8-yoke as shown in FIG. 3 and the duty ratio of the pulse wave, and the relationship between the maximum detection distance. By comparing the duty ratio of the pulse wave with the maximum detection distance for each angle in FIG. 9, it can be seen that the maximum detection distance increases when the duty ratio of the pulse wave approaches 50%. Also sample
No. indicates the number of the detection element 3 used for the measurement. From this, the duty ratio of the pulse wave can be set within a desired range by rotating and sliding the lid-shaped yoke 8, and as a result, the lid-shaped yoke can be adjusted to a position where the maximum detection distance is obtained.

In a specific example, the top surface portion of the lid-shaped yoke may have a semicircular shape as shown in FIG. 10 instead of the circular shape shown in FIG. Further, the lid-shaped yoke 8 may be a half-cut of the lid-shaped yoke 8 as shown in FIG. For example, as described above, the present invention is not limited to the above specific examples.

[0022]

The moving state detecting device of the present invention described above has the following effects.

(Effect of the first embodiment) By covering the lid-shaped yoke from above the magnetic flux generation means, the magnetic flux generated from the magnetic flux generation means suppresses the divergence of the magnetic flux to the peripheral region, and the lid-shaped yoke is efficiently provided. Flows from the top to the side of the and goes to the opening. As a result, there is an effect that the magnetic flux from the magnetic flux generating means is positively concentrated on the magnetic flux sensing element.

(Effect of Second Concrete Example) 2 in the detecting element 3
Even when the individual magnetic flux sensing elements are arranged side by side in the arrangement direction of the convex portion and the concave portion of the moving body 7 to be detected, similarly, the magnetic flux generated from the magnetic flux generating means suppresses the divergence of the magnetic flux to the peripheral region and efficiently. It flows from the top surface of the lid-like yoke to the side surface and then toward the opening. As a result, there is an effect that the magnetic flux from the magnetic flux generating means is positively concentrated on the magnetic flux sensing element.

(Effect of Third Specific Example) 2 in the detecting element 3
When the magnetic flux sensing elements are arranged side by side in the arrangement direction of the convex portion and the concave portion of the moving body to be detected 7, a lid-like yoke having a defect portion smaller than the size of the opening portion at the other end at a position off the center of the top surface portion. By rotating and sliding, the magnetic field applied to the two magnetic flux sensing elements arranged in parallel can be adjusted, and the lid-shaped yoke can be adjusted to the position where the maximum detection distance is obtained.

[Brief description of drawings]

FIG. 1 shows a sectional view of a moving state detecting device of the present invention.

FIG. 2 shows a cross-sectional view of a conventional movement state detection device.

FIG. 3 is a perspective view showing a relationship between a lid-shaped yoke, a spacer and a magnet according to an embodiment of the present invention.

FIG. 4 is a characteristic diagram showing an output voltage V0.

FIG. 5 is a characteristic diagram showing an output of a differential voltage (ΔV = Va−Vb).

6 is a block diagram of processing means A. FIG.

FIG. 7 is a characteristic diagram showing an output of a pulse wave.

8 is a block diagram of processing means B. FIG.

FIG. 9 is a characteristic diagram showing the relationship between the rotation angle and the duty ratio of the lid-shaped yoke in the second specific example.

FIG. 10 is a perspective view of another lid-shaped yoke showing an embodiment of the present invention.

FIG. 11 is a perspective view of another lid-shaped yoke showing an embodiment of the present invention.

FIG. 12 is a perspective view showing a relationship between a semi-circular yoke and a magnet showing an example of a conventional product.

FIG. 13 is a chart comparing amplitude values of a differential voltage (ΔV = Va−Vb) when an example of the lid-shaped yoke of the present invention and a conventional semi-circular yoke are used.

[Explanation of symbols]

 1 Cylindrical yoke 2 Lid member 3 Detection element 4 Cylindrical magnet 5 Semi-circular yoke 6 Filler 7 Detected moving body 8 Lid-shaped yoke 9 Spacer 10 Signal output line

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshifumi Oketani 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDK Corporation (72) Sawako Kuwahara 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDK Within the corporation

Claims (3)

[Claims] 1. A magnetic material, at least 1.
A detected moving body having one convex portion and at least one concave portion and moving in the arrangement direction of the convex portion and the concave portion; and a magnetic flux sensing element arranged so as to correspond to the detected movable body. Processing means for processing an output of the magnetic flux sensing element to generate an electric signal indicating a moving state of the detected moving body; and a processing means for forming a magnetic flux passing through the detected moving body and the magnetic flux sensing element. A moving state detecting device including a magnetic flux generating means and a yoke, the yoke being covered by the magnetic flux generating means so as to concentrate the magnetic flux, and having an opening corresponding to the moving body to be detected. A moving state detection device, which is a lid-shaped yoke having a. 2. A magnetic material formed of at least 1.
A moving body to be detected, in which one projecting portion and at least one recessed portion are arranged, and which moves in the arraying direction of the projecting portion and the recessed portion, and two arranged in the array direction so as to correspond to the moving body to be detected. Magnetic flux sensing element, processing means for processing an output of the magnetic flux sensing element to generate an electric signal representing a moving state of the detected moving body, and forming a magnetic flux passing through the detected moving body and the magnetic flux sensing element. A moving state detecting device, comprising: a magnetic flux generating means provided so as to provide a magnetic field; and a yoke, the yoke being covered by the magnetic flux generating means so as to concentrate the magnetic flux, and the moving body to be detected. Is a lid-like yoke having an opening corresponding to the above. 3. The moving state detecting device according to claim 2, wherein the lid-shaped yoke has a defect portion smaller than the opening formed at a position off the center of the top surface portion, and the detected movement is detected. A moving state detecting device, which is operably provided so as to adjust a magnetic flux passing through a body and the magnetic flux sensing element.