JP2004177339A - Position detecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-sized position detecting device capable of keeping sensitivity intact using a surface mounted element having a magnetism detecting element. <P>SOLUTION: The magnetism detecting element 61 is mounted on a substrate 7. When a detected body 9 is close to a position outside both extending sections 10a and substantially parallel with the extending direction and comes into a detected region, the magnetic flux of a magnet 10 is rectangular to the substrate 7. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a magnetic detection sensor including a combination of a magnetic detection element and a magnet mounted on a substrate, and outputs a signal corresponding to the proximity of the magnetic body when the magnetic body approaches the magnetic detection sensor. The present invention relates to such a position detecting device.
[0002]
[Prior art]
Conventionally, in a position detection device having a magnetic detection sensor having such a configuration, a magnet constituting the magnetic detection sensor includes a base and a pair of extending portions extending from both ends of the base in a direction perpendicular to the base. It is magnetized so as to form a magnetic flux-free region between the portions. Then, a magnetic detection element is arranged in this magnetic flux-free area, and when the magnetic body approaches the front ends of both extending portions, the magnetic flux-free area is canceled out, and the magnetic detection element is moved from the base of the magnet to the U. A configuration is adopted in which a magnetic flux that goes to the outside of the character shape passes and this magnetic flux is detected (for example, see Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent No. 2921603 [0004]
[Problems to be solved by the invention]
The magnetic sensing element has a terminal that can be cut to adjust its length or bend and change its shape, and if necessary, processed after the terminal, is mounted on a substrate after mounting, and a magnetic sensing element There is a surface mount type which is a chip type and is directly mounted on a substrate.
[0005]
The lead type has the advantage that the terminals can be bent, so that the orientation of the magnetic sensing element can be freely set with respect to the substrate and mounted, and the substrate can be freely arranged with respect to the permanent magnet. There is a problem that an automatic mounting device cannot be used for mounting on the base, and the manufacturing cost is high.
[0006]
On the other hand, the surface mounting type has an advantage that the magnetic sensing element and the substrate can be combined in a small size, and the automatic mounting device can be mounted at low cost. However, in the case of the surface mount type, since the magnetic sensing element is directly mounted on the board, the orientation of the magnetic sensing element with respect to the board is determined. The arrangement is also decided. For example, in the conventional position detecting device that detects the proximity of the object to be detected on the distal ends of the two extending portions described above, when applying a surface-mount type magnetic detecting element, the base portion is more than the distal end of the extending portion. It is arranged to go outside. For this reason, the distance between the object to be detected and the tip of the extending portion is increased, which causes a problem that the detection sensitivity cannot be increased. In order to avoid this, the lead type is adopted, and the base portion is arranged so as not to go outside from the tip of the extending portion to secure the sensitivity, and the assembly cost has to be sacrificed.
[0007]
Therefore, an object of the present invention is to solve such a problem by realizing a position detecting device having excellent sensitivity, and using a surface-mount type magnetic detecting element that can be used at a low cost. It is to be.
[0008]
[Means for Solving the Problems]
An invention according to claim 1, which has been made to solve the above technical problem, is a single magnet having an extending portion extending at least on both sides, and a magnetic detecting element arranged at a predetermined position between the extending portions. The magnetic detection element outputs a signal corresponding to detection when the detected object is located in a detection range within a predetermined range from the magnet, and does not detect when the detected object is positioned outside the detection range. In a position detection device configured to output a signal corresponding to
The magnetic sensing element is mounted on a substrate, and when the object to be detected approaches the position outside the both extending portions and substantially parallel to the extending direction and enters the detection area, the magnetic flux of the magnet is applied to the substrate. On the other hand, the configuration is such that the component in the right-angle direction can be detected.
[0009]
According to this configuration, the object to be detected comes to be detected close to the side surface of the magnet, and the distance between the object to be detected and the magnet can be set small regardless of the positions of the magnetic detection element and the substrate. And good detection sensitivity can be ensured.
[0010]
In addition to the first means, a second technical means adopted in the invention is that the magnetic sensing element is a surface mount type.
[0011]
With this configuration, the magnetic detection element can be mounted on the base by an automatic mounting device, and the cost can be reduced.
[0012]
Further, in addition to the first or second means, a third technical means adopted in the invention is that the magnet is provided with a locking portion for supporting the substrate.
[0013]
With this configuration, the position of the magnetic detection element with respect to the magnet is accurately secured, and the detection accuracy is improved.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a position detecting device 1 according to the present invention will be described with reference to the accompanying drawings 1 to 3.
[0015]
As shown in the exploded perspective view of FIG. 1, the position detecting device 1 includes a magnet 10 serving as its frame. The magnet 10 has a single external shape in the shape of a rectangular parallelepiped, and has a substantially rectangular hole 4 formed on one side surface of the rectangular parallelepiped. The hole 4 has a bottom portion 5 at a predetermined depth, and a pair of grooves 2 (locking portions) extending from the open portion of the hole 4 to the bottom portion 5 are provided on opposite side surfaces of the hole 4.
[0016]
Further, as shown by the arrow in FIG. 1, a rectangular substrate 4 having a flat surface whose left and right end surfaces are locked by the groove 2 is fitted into the hole 4 of the magnet 10. On one surface of the substrate 4 is mounted a surface mounting type surface mounting element 6 which is directly mounted without a terminal. The surface mount element 6 includes a magnetoelectric detection element 61 using a known Hall element or the like that generates a predetermined output when the magnetic flux density reaches a predetermined value or more. Such a magnetoelectric detecting element 61 detects a magnetic flux in a direction perpendicular to the substrate 4 to be mounted. The substrate 4 is provided with peripheral electronic circuits required for the magnetoelectric detection element 61 and is configured to be small.
[0017]
As shown in FIGS. 2 and 3, the magnet 10 is magnetized with an N pole at the edge 3 and the bottom 5 of the hole 4 which is one side of the rectangular parallelepiped, and the side of the rectangular parallelepiped opposite to the bottom 5 is The S pole is magnetized. In the case where there is no magnetic body close to the magnet 10 in the magnetized in this way, the lines of magnetic force from each N interfere with each other at the outer portion of the hole 4 as shown by the dotted ellipse in FIG. Then, a region A where no magnetic force is applied is formed. Usually, the magnetoelectric detecting element 61 is assembled by locking the substrate 4 in the groove 2 so as to be located in the region A of the non-magnetic force.
[0018]
However, as described later, the magnetoelectric detection element 61 detects and determines a magnetic flux that changes due to the proximity of the magnetic body 9, and slightly deviates from the region A so that the change in the magnetic flux can be detected stably. It may be arranged at a position. It is apparent that there is no problem even if the magnetization of the magnet 10 is changed so that the north pole and the south pole are reversed with respect to the above embodiment.
[0019]
As shown in FIG. 3, the magnetic body 9 and the magnet 10 serving as the detection target are the outer surfaces of the rectangular parallelepiped of the magnet 10 and are substantially parallel to the extending direction of the hole 4 into which the substrate 7 is inserted. It is arranged so as to be close to the side surface. Accordingly, the substrate 7 is disposed in the hole 4 formed in the magnet 10, the distance between the magnet and the magnetic body 9 can be set small, and good detection sensitivity can be ensured. The moving direction of the magnetic body 9 when approaching may be any direction, and is detected when the magnetic body 9 reaches a predetermined detection area.
[0020]
The accuracy of the mounting position of the magnetoelectric detection element 61 is ensured by being locked in the groove 2, and the variation in the output of the magnetoelectric detection element 61 caused by the variation in the position of the magnetoelectric detection element 61 with respect to the magnet 10 is suppressed to a small value. The accuracy is improved.
[0021]
Next, the operation of the position detecting device 1 configured as described above will be described.
[0022]
As shown in FIG. 3, when the magnetic body 9 is at a non-detection position separated from the magnet 10 by a two-dot chain line, the magnetic flux is in the state shown in FIG. Numeral 61 denotes a non-magnetic area A, and the magnetoelectric detecting element 61 outputs a signal corresponding to non-detection. When the magnetic body 9 moves to a position aligned with the side surface of the magnet 10 as shown by a solid line in FIG. 3, the balance of the lines of magnetic force changes, and the region of non-magnetic force is changed from the magnetic body 9 to the magnetic body as shown in FIG. Move to the 9 side. Then, the magnetoelectric detection element 61 is located outside the nonmagnetic area B. At this time, the magnetic flux passes through the magnetoelectric detection element 61 with an increased component in a direction perpendicular to the surface of the substrate 7. Then, the magnetoelectric detecting element 61 detects the magnetic flux and outputs a signal corresponding to the detection. As described above, the detection range is the range of the position of the magnetic body 9 with respect to the side surface of the magnet 10 when the component of the magnetic flux in the perpendicular direction passes through the magnetoelectric detection element 61 with a predetermined strength.
[0023]
In the above-described embodiment, the magnet 10 has a rectangular parallelepiped shape. However, as is apparent from the above description, it is parallel to the substrate 7 that generates the magnetic force lines contributing to the detection of the magnetic body 9 in the magnet 10. Two sides which are perpendicular to the other substrate 7 are used for supporting the substrate 7. Therefore, two sides parallel to the substrate 7 that generates the lines of magnetic force may be formed as the extending portions 10a (FIG. 2), and two sides perpendicular to the substrate 7 may be formed of, for example, a resin material, and may be integrally assembled with the magnet 10. good.
[0024]
【The invention's effect】
In the position detection device configured as described above, since the object to be detected is detected close to the side surface of the magnet, the distance between the object and the magnet is determined regardless of the position of the magnetic detection element and the substrate. It can be set small and good detection sensitivity can be secured. In addition, since the magnetic detection element is a surface-mount type, the magnetic detection element can be mounted on a base by an automatic mounting device, and can be manufactured at low cost.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a position detecting device according to the present invention.
FIG. 2 is a cross-sectional view showing a state of a magnetic flux when a position detecting device according to the present invention does not detect a magnetic body.
FIG. 3 is a cross-sectional view showing a state of a magnetic flux when a position detecting device according to the present invention detects a magnetic body.
[Explanation of symbols]
1 position detector 2 locking part (groove)
4 hole 6 surface mount element 7 substrate 9 object to be detected (magnetic material)
10 Magnet 10a Extension 61 Magnetic Detector

Claims (3)

A single magnet with extensions extending at least on both sides;
A magnetic detecting element disposed at a predetermined position between the extending portions, wherein the magnetic detecting element outputs a signal corresponding to the detection when the object to be detected is located in a detection area within a predetermined range from the magnet. And, in the position detection device configured to output a signal corresponding to non-detection when the detected object is located outside the detection area,
The magnetic sensing element is mounted on a substrate, and when the object to be detected approaches the position outside the both extending portions and substantially parallel to the extending direction and enters the detection area, the magnetic flux of the magnet is applied to the substrate. A position detecting device configured to detect a component in a direction perpendicular to the position detecting device. 2. The position detecting device according to claim 1, wherein the magnetic detecting element is a surface mount type. The position detecting device according to claim 1 or 2, wherein the magnet is provided with a locking portion that supports the substrate.

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