JP2002318240A - Moving matter detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moving matter detector capable of preventing the deformation of a circuit board by the stress of a filler and the damage of an electronic part or the generation of a crack in a soldered place, and capable of simplifying planning and manufacturing processes. SOLUTION: The moving matter detector 1 is constituted by housing a magnetic detection element 3 for detecting the moving state of an object to be detected in a resin case 2, arranging the same at the predetermined position on the side of the detection surface 2c of the resin case 2, and filling the resin case with the filler 7 to hold the magnetic detection element 3 in the resin case 2. The detector has the circuit board 4 on which the magnetic detection element 3 or other electronic part is arranged, and a magnet 5 applying a magnetic field to the magnetic detection element 3. A recessed part 6b in which the magnet 5 is arranged, and the stress suppressing part 6g provided so as to be opposed to the circuit board 4 and suppressing the stress due to the filler 7 applied to at least the circuit board 4, are provided to the moving matter detector, and the magnet holder 6 arranged to the circuit board 4 is also provided thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving object detector for detecting a moving state of a moving object such as a gear or a multi-pole magnetized magnet.

[0002]

2. Description of the Related Art Conventionally, as a moving object detector for detecting a moving distance and a moving speed (moving state of a moving object performing a rotational movement), for example, a moving object detector disclosed in Japanese Patent Application Laid-Open No. 2-264817 is known. ing. Such a moving object detector is
A cylindrical resin case, a lid disposed on the upper end of the resin case, the detection object side forming a flat portion, a magnetic detection element mounted on the inner surface side of the lid, and the magnetic detection element. And a filler made of epoxy or the like held in the resin case.

[0003]

In the moving object detector having such a structure, the magnetic detecting element and other electronic components are provided on a circuit board, and the circuit board is provided in the resin case. Thereafter, the filler is filled in the resin case to hold the magnetic detection element in the resin case.

However, when the filler is filled in the resin case, the circuit board is directly subjected to the stress of the filler, and the stress of the filler causes deformation of the circuit board and damage to the circuit board. There is a possibility that the electronic components to be arranged may be damaged or cracks may occur at the soldered portions. Since the problem is likely to occur, it is necessary to devise the structure of the resin case body or to monitor the filling amount of the filler, which causes a problem that the design becomes complicated and the manufacturing process becomes complicated. Had.

In view of the above problems, the present invention can prevent the deformation of a circuit board, the damage of electronic components, and the occurrence of cracks in soldered portions due to the stress of a filler. It is an object of the present invention to provide a moving object detector capable of simplifying the following.

[0006]

According to the present invention, in order to solve the above-mentioned problems, a magnetic detecting element for detecting a moving state of an object to be detected is housed in a resin case, and the magnetic detecting element is mounted on a detecting surface of the resin case. A moving object detector that is disposed at a predetermined position on the side and fills the resin case with a filler and holds the magnetic detection element in the resin case, wherein the magnetic detection element and other electronic components are A circuit board to be provided, a magnet for applying a magnetic field to the magnetic detection element, a concave portion for providing the magnet, and a stress provided by the filler applied to the circuit board at least to face the circuit board. And a magnet holder provided on the circuit board.

[0007] A predetermined space is provided between the circuit board and the stress suppressing portion.

A magnetic detecting element for detecting a moving state of the object to be detected is housed in a resin case, and the magnetic detecting element is arranged at a predetermined position on a detection surface side of the resin case, and is filled in the resin case. A moving object detector that fills the material and holds the magnetic detection element in the resin case,
A circuit board on which the magnetic detection element and other electronic components are provided, a magnet for applying a magnetic field to the magnetic detection element, a concave portion on which the magnet is provided, and both surfaces of the circuit board are provided to face each other. A magnet holder provided on the circuit board, comprising: first and second stress suppressing portions for suppressing at least stress caused by the filler applied to the circuit board;
It is characterized by comprising.

Further, a predetermined space is provided between the circuit board and the first and second stress suppressing portions.

Further, at least one of the first and second stress suppressing portions is provided so as to be detachable from the magnet holder.

Further, the magnet holder is provided with an arrangement portion for arranging the magnet holder at a predetermined position on the circuit board.

Further, the magnet holder is characterized in that a guide for guiding the filler toward the surface to be detected in the resin case is formed.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

The moving object detector 1 is, as shown in FIG.
A substantially cylindrical resin case 2 and a circuit board 4 on which a magnetic detection element 3 composed of a Hall IC or an MR element (semiconductor magnetoresistive element) and an electronic component (not shown) composed of a capacitor, an amplifier, a resistor, etc. A magnet 5 for applying a magnetic field to the magnetic detecting element 3, a magnet holder 6 on which the magnet 5 is disposed and disposed on a circuit board 4, and a resin case 2
And a filler 7 made of epoxy or the like for fixing inside.

The resin case 2 has, for example, a mounting piece 2a for mounting and fixing to a cover body (not shown) of a transmission or the like with screws or the like. A guide wall 2b for guiding and supporting the board 4 to the bottom of the resin case 2 is formed to a predetermined position, and the mounting piece 2a and the guide wall 2b are formed integrally with the resin case 2. Such a resin case 2 has a detection surface (bottom surface) 2c corresponding to the shape of the object to be detected, and the thickness of the detection surface 2c is formed so as to be thinner than the thickness of other portions. ing.

As shown in FIG. 2, the circuit board 4 is used to electrically connect a power supply input from the outside and an electric cord 8 for output of the magnetic sensing element 3 to a land (not shown) by soldering. (A land is formed on one surface). The circuit board 4 is provided with a first contact portion 4 b for determining a placement position when the magnet holder 6 described in detail later is provided, and the circuit board 4 is provided with respect to the resin case 2. Second contact portion 4 that contacts the end of guide wall 2b of resin case 2 to determine the position
and c.

As shown in FIGS. 2 and 3, the magnet holder 6 is made of a substantially semi-cylindrical resin material, and has a mounting portion 6a which is substantially horizontal with respect to the circuit board 4, and a magnet 5 disposed therein. 6b, and the end face 6c and the detection surface of the magnetic detection element 3 are substantially the same when the magnetic detection element 3 is provided, and the detection surface of the magnetic detection element 3 is formed. It has a stepped portion 6d to be brought into contact with the detection surface 2c of the resin case 2 and a positioning portion 6e formed on the stepped portion 6d for determining the arrangement position of the magnetic detection element 3. Further, the magnet holder 6 includes a pair of arm pieces (arranged portions) 6f formed integrally with the main body from the mounting portion 6a and having a substantially L-shaped cross section.
The magnet holder 6 is arranged on the circuit board 4 by inserting the circuit board 4 into the arm piece 6f, and the side surface of the arm piece 6f is brought into contact with the first contact portion 4b of the circuit board 4. Then, the arrangement position of the magnet holder 6 with respect to the circuit board 4 is determined.

The magnet holder 6 has a substantially concave stress suppressing portion 6g formed so as to face the circuit board 4 and suppressing the stress caused by the filler 7 applied to the circuit board 4 and the electronic components. As shown in FIG. 1, the volume of the filler 7 that applies stress to the circuit board 4 and the electronic component is reduced by forming the stress suppressing portion 6g, and the stress is suppressed. In other words, by providing the predetermined space S1 between the circuit board 4 and the stress suppressing portion 6g, it is possible to make the stress applied to the front and back surfaces of the circuit board 4 by the filling member 7 substantially uniform. It is possible to prevent an excessive stress that is biased on the surface from being applied.

The magnet holder 6 is provided with a filler 7 at a plurality of peripheral edges along the longitudinal direction.
A guide 6h having a substantially concave shape for guiding to the side b is provided. Therefore, when the filler 7 is filled in the resin case 2, the air in the resin case 2 is discharged to the outside from the guide portion 6 h, so that the filler 7 is favorably injected into the resin case 2. become.

As a method of manufacturing the moving object detector 1 having such a configuration, the magnet 5 is disposed in the concave portion 6b of the magnet holder 6, and then the magnetic detection is performed by the positioning portion 6e formed in the step 6d of the magnet holder 6. The element 3 is arranged, and a lead 3 a for electrically connecting the magnetic sensing element 3 to the circuit board 4 is homed in the direction of the circuit board 4. Then, the magnet holder 6
The circuit board 4 is inserted until the first contact portion 4b formed on the circuit board 4 on which the electronic components and the like are disposed is brought into contact with the side ends of the pair of arm pieces 6f. 3a
Is soldered to a land (not shown) formed on the circuit board 4.

The electric cord insertion hole 4 of the circuit board 4
The electric cord 8 is inserted into the circuit board 4 and the electric cord 8 is soldered to the land of the circuit board 4. Then, the circuit board 4 is moved along the guide wall 2 b formed in the resin case 2, and the end of the circuit board 4 is pressed by a special jig while a predetermined pressure is applied thereto. The contact portion 4c is brought into contact with the end of the guide wall 2b, and the position of the magnetic detection element 3 disposed on the circuit board 4 is temporarily fixed to the resin case 2. After that, the resin case 2 is filled with the filler 7 and cured, whereby the magnetic detection element 3 is disposed and fixed to the resin case 2. Thus, the moving object detector 1 is completed.

The moving object detector 1 having the above-described structure includes the magnet holder 6 provided on the circuit board 4 and the stress suppressing portion 6g formed so as to face the circuit board 4. It is possible to adjust the volume of the filler 7 that applies stress to the electronic component, and it is possible to prevent the deformation of the circuit board 4 due to the stress of the filler 7, damage to the electronic component, and generation of cracks at soldered locations. Becomes In particular, a predetermined space S between the circuit board 4 and the stress suppressing portion 6g.
When 1 is provided, both the front surface and the back surface of the circuit board 4 can be fixed with the filler 7 and the stress applied to the front surface and the stress applied to the back surface of the circuit board 4 are adjusted substantially equally. Thus, the design and manufacturing process of the moving object detector 1 can be simplified.

Further, the magnet holder 6 is
Is provided with an arm piece 6f for disposing the magnet holder 6 at a predetermined position on the circuit board 4, so that the magnet holder 6 can be easily mounted on the circuit board 4.
At a predetermined position.

Further, by providing the magnet holder 6 with the guide 6h for guiding the filler 7 to the detection surface 2b side in the resin case 2, the filler 7 can be efficiently filled in the entire resin case 2. Becomes

Next, another embodiment of the present invention will be described with reference to FIGS. 4 and 5. The same or corresponding portions as those in the above-described embodiment are denoted by the same reference numerals and detailed description thereof will be given. Description is omitted.

The difference from the above-described embodiment is that, as shown in FIGS. 4 and 5, the second stress which is integrally formed on the magnet holder 6 via the arm piece 6f and is detachable from the magnet holder 6 is shown. This is to provide the suppression unit 6i.

In the moving object detector 1, the arrangement position of the magnetic detection element 3 arranged in the resin case 2 differs depending on the shape of the object to be detected. In this case, when the arrangement position of the magnetic detection element 3 is changed, the stress caused by the filler 7 received by the circuit board 4 and the electronic components arranged on the circuit board 4 also changes, and the circuit board 4 is deformed. In addition, there is a possibility that the electronic component may be damaged or a soldering portion may be cracked. Further, it is conceivable to change the shape of the stress suppressing portion 6g formed on the magnet holder 6 according to the shape of the detection target. Will be high.

To solve the above problems, the magnet holder 6
First, a first formed so as to face the back surface of the circuit board 4.
And the second stress suppressing portion 6i formed so as to face the surface of the circuit board 4, the stress caused by the filler 7 on the back surface of the circuit board 4 is reduced by the first stress suppressing portion 6g. Of the filler 7 in the space S1 provided between the stress suppressor 6g and the circuit board 4, and the stress caused by the filler 7 on the surface of the circuit board 4 is equal to the second stress suppressor 6i and the circuit. This is the volume of the filler 7 in the space S2 provided between the substrate 4 and the substrate. Therefore, even when the arrangement position of the magnetic detection element 3 is changed depending on the shape of the detection target, it is possible to make the stress caused by the filler 7 received on both surfaces of the circuit board 4 substantially uniform.

Further, in the structure of the resin case 2, if the second stress suppressing portion 6 i is not required depending on the disposition position of the magnetic detecting element 3, the second stress suppressing portion 6 i is moved from the magnet holder 6. Since the magnet holder 6 can be detached and disposed on the circuit board 4, only the magnet holder 6 having the second stress suppressing portion 6i needs to be prepared.
It is not necessary to prepare a plurality of types.

In the embodiment of the present invention, the circuit board 4 is formed with the second contact portion 4c which is in contact with the resin case 2. However, the circuit board 4 is provided on the guide wall 2b of the resin case 2. 4 may be formed.

Further, in the embodiment of the present invention, the circuit board 4 is moved along the guide wall 2b of the resin case 2 and the circuit board 4 is pressed into the resin case 2 so that the magnetic detecting element 3 is moved to the resin case 2. The magnet holder 6 is temporarily fixed to a predetermined position. However, a convex positioning portion is formed at a peripheral portion along the longitudinal direction of the magnet holder 6, and the positioning portion is fixed to the resin case 2.
The magnetic detection element 3 may be temporarily fixed to a predetermined position in the resin case 2 by being fitted into the guide wall 2b.

In another embodiment of the present invention, the second stress suppressing portion 6i formed integrally with the magnet holder 6 is configured to be detachable from the magnet holder 6. In the described invention, for example,
The first stress suppressing portion 6g may have a structure equivalent to that of the second stress suppressing portion 6i, and the first stress suppressing portion 6g may be detachable from the magnet holder 6, and the first stress suppressing portion 6g and the second stress suppressing portion 6g may be detachable from the magnet holder 6. The structure is not limited to the above-described embodiment as long as at least one of the stress suppressing portions 6i is removed.

[0033]

According to the present invention, a magnetic detecting element for detecting a moving state of an object to be detected is housed in a resin case, and the magnetic detecting element is arranged at a predetermined position on a detection surface side of the resin case. A moving object detector that fills a filling material therein and holds the magnetic detection element in a resin case, and a circuit board on which the magnetic detection element and other electronic components are disposed.
A magnet that applies a magnetic field to the magnetic detection element, a concave portion in which the magnet is provided, and a stress suppression unit that is provided to face the circuit board and that suppresses stress caused by the filler applied to at least the circuit board. And a magnet holder disposed on the circuit board, and the deformation of the circuit board due to the stress of the filler, the breakage of the electronic components and the occurrence of cracks at the soldered portions. This makes it possible to simplify the design and manufacturing process of the moving object detector.

The present invention also provides a magnetic sensor for detecting a moving state of an object to be detected is housed in a resin case, and the magnetic sensor is disposed at a predetermined position on a detection surface side of the resin case. A moving object detector that fills a case with a filler and holds the magnetic detection element in the resin case, a circuit board on which the magnetic detection element and other electronic components are disposed, and the magnetic detection element A magnet that applies a magnetic field to
A concave portion in which the magnet is provided, and first and second stress suppressing portions provided so as to face both surfaces of the circuit board, and suppressing at least stress caused by the filler applied to the circuit board, And a magnet holder disposed on the circuit board,
Even when the position of the magnetic sensing element in the resin case is changed depending on the shape of the object to be detected, deformation of the circuit board due to the stress of the filler, breakage of the electronic components, and cracks at the soldered spots occur Can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of a moving object detector according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the circuit board and the magnet holder according to the first embodiment;

FIG. 3 is a front view showing the circuit board and the magnet holder according to the first embodiment;

FIG. 4 is a sectional view of a main part showing a moving object detector according to another embodiment of the present invention.

FIG. 5 is a perspective view showing the circuit board and the magnet holder according to the first embodiment;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Moving object detector 2 Resin case 3 Magnetic detection element 4 Circuit board 5 Magnet 6 Magnet holder 6f Arm piece (arranged part) 6g Stress suppression part (First stress suppression part) 6h Guide part 6i Second stress suppression part 7 Filler S1 space S2 space

Claims (7)

[Claims] 1. A magnetic detecting element for detecting a moving state of an object to be detected is housed in a resin case, and the magnetic detecting element is arranged at a predetermined position on a detection surface side of the resin case and is filled in the resin case. A moving object detector for filling the material and holding the magnetic detecting element in the resin case, and applying a magnetic field to the circuit board on which the magnetic detecting element and other electronic components are disposed; A magnet, a concave portion in which the magnet is disposed, and provided to face the circuit board;
A moving object detector comprising: at least a stress suppressing unit that suppresses a stress caused by the filler applied to the circuit board; and a magnet holder disposed on the circuit board. 2. The moving object detecting device according to claim 1, wherein a predetermined space is provided between the circuit board and the stress suppressing section. 3. A magnetic detecting element for detecting a moving state of the object to be detected is housed in a resin case, and the magnetic detecting element is arranged at a predetermined position on a detection surface side of the resin case, and is filled in the resin case. A moving object detector for filling the material and holding the magnetic detection element in the resin case, and applying a magnetic field to the circuit board on which the magnetic detection element and other electronic components are disposed; A magnet, a concave portion in which the magnet is provided, and first and second stress suppressing portions provided on both sides of the circuit board so as to face each other and suppressing at least a stress caused by the filler applied to the circuit board; And a magnet holder provided on the circuit board. 4. The moving object detector according to claim 3, wherein a predetermined space is provided between the circuit board and the first and second stress suppression units. 5. The device according to claim 3, wherein at least one of the first and second stress suppressing portions is provided detachably from the magnet holder. Moving object detector. 6. The magnet holder according to claim 1, wherein the magnet holder includes an arranging portion for arranging the magnet holder at a predetermined position on the circuit board. 3. A moving object detector according to claim 1. 7. The magnet holder according to claim 1, wherein a guide portion for guiding the filler toward the surface to be detected in the resin case is formed in the magnet holder. Moving object detector.