JP3479975B2 - Moving object detector - Google Patents

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 the moving state of a moving object such as a gear or a magnet with multi-pole magnetization.

[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 which makes a rotational movement), for example, one disclosed in Japanese Patent Laid-Open No. 2-264817 is known. ing. Such a moving object detector is
A cylindrical resin case, a lid body provided on the upper end portion of the resin case and having a flat portion on the detected body side, a magnetic detection element mounted on the inner surface side of the lid body, and the magnetic detection element. It is composed of 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 detection element and other electronic parts are arranged on a circuit board, and the circuit board is arranged in the resin case. Then, the filling material is filled in the resin case to hold the magnetic detection element in the resin case.

However, when the filling material is filled in the resin case, the circuit board is directly subjected to the stress of the filling material, and the stress of the filling material causes the deformation of the circuit board and the circuit board. There is a risk of damage to the electronic components arranged and cracks in the soldering points, and especially when there is a significant difference in stress received between the front surface and the back surface of the circuit board depending on the arrangement position of the circuit board. Since problems are likely to occur, it is necessary to devise the structure of the resin case body or to monitor the filling amount of the filling material, which complicates the design and the manufacturing process. Had.

In view of the above problems, the present invention can prevent the deformation of the circuit board, the damage of the electronic parts and the cracking of the soldering points due to the stress of the filler, and the designing and manufacturing process. An object of the present invention is to provide a moving object detector capable of simplifying.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention accommodates a magnetic detection element for detecting a moving state of an object to be detected in a resin case, and the magnetic detection element is attached to the detection surface of the resin case. A moving object detector which is disposed at a predetermined position on the side and holds the magnetic detection element in the resin case by filling a filling material in the resin case, wherein the magnetic detection element and other electronic parts are a circuit board disposed, wherein a magnet providing a magnetic field to the magnetic detection element, a recess for disposing the magnet, provided so as to face the circuit board, before
The stress applied to the surface of the circuit board by the filling material
And the stress applied to the back surface of the circuit board are adjusted almost evenly.
And a magnet holder arranged on the circuit board.

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

Further, a magnetic detection element for detecting the moving state of the object to be detected is housed in a resin case, the magnetic detection element is arranged at a predetermined position on the detection surface side of the resin case, and is filled in the resin case. A moving object detector which is filled with a material and holds the magnetic detection element in the resin case,
A circuit board on which the magnetic detection element and other electronic parts are arranged, a magnet for applying a magnetic field to the magnetic detection element, a concave portion on which the magnet is arranged, and both sides of the circuit board are provided so as to face each other. A magnet holder disposed on the circuit board, comprising at least first and second stress suppressing sections for suppressing stress due to 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 stress suppressing portions of the first and second stress suppressing portions is detachably provided from the magnet holder.

Further, the magnet holder is characterized by comprising 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 portion for guiding the filling material to the surface to be detected in the resin case is formed.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION 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 including a Hall IC, an MR element (semiconductor magnetic resistance element) and the like, and an electronic component (not shown) including a capacitor, an amplifier, a resistor and the like are arranged. The magnet 5 for applying a magnetic field to the magnetic detection element 3, the magnet holder 6 provided with the magnet 5 and arranged on the circuit board 4, and the magnetic detection element 3 in the 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 a screw or the like, and the inner wall of the resin case 2 has a circuit which will be described later in detail. A guide wall 2b for guiding and supporting the substrate 4 to the bottom of the resin case 2 is formed up to a predetermined position, and the mounting piece 2a and the guide wall 2b are integrally formed on the resin case 2. Such a resin case 2 has a detection surface (bottom surface) 2c according to the shape of the detected object, and the thickness of this detection surface 2c is formed to be thinner than the thickness of other portions. ing.

As shown in FIG. 2, the circuit board 4 is for electrically connecting the power source inputted from the outside and the electric cord 8 for outputting the magnetic detection element 3 to the land portion (not shown) by soldering. Of the electric cord insertion hole 4a (land is formed on one surface). Further, the circuit board 4 is provided with the first contact portion 4b for determining the arrangement position when the magnet holder 6 described later is arranged, and the circuit board 4 is arranged with respect to the resin case 2. The second contact portion 4 that contacts the end of the guide wall 2b of the 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 is provided with a mounting portion 6a which is substantially horizontal to the circuit board 4 and a magnet 5. Is formed above the concave portion 6b, and when the magnetic detecting element 3 is arranged, the end surface 6c and the detecting surface of the magnetic detecting element 3 are substantially the same surface, and the detecting surface of the magnetic detecting element 3 is It is provided with a step portion 6d that abuts on the detection surface 2c of the resin case 2 and a positioning portion 6e that is formed on the step portion 6d and that determines the arrangement position of the magnetic detection element 3. Further, the magnet holder 6 includes a pair of arm pieces (arrangement portions) 6f which are formed integrally with the main body from the mounting portion 6a and have a substantially L-shaped cross section.
The magnet holder 6 is disposed 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. , The arrangement position of the magnet holder 6 with respect to the circuit board 4 is determined.

Further, the magnet holder 6 is provided with a substantially concave stress suppressing portion 6g which is formed so as to face the circuit board 4 and suppresses the stress due to the filler 7 applied to the circuit board 4 and the electronic component. As shown in FIG. 1, by forming the stress suppressing portion 6g, the volume of the filler 7 that applies stress to the circuit board 4 and the electronic component is reduced, 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, the stress due to the filler 7 applied to the front surface and the back surface of the circuit board 4 can be made substantially equal, and It is possible to prevent a biased excessive stress from being applied to the surface.

In addition, the magnet holder 6 is provided with a filler 7 at a plurality of peripheral edges along the longitudinal direction and a detection surface 2 in the resin case 2.
The guide portion 6h having a substantially concave shape that leads to the b side is provided. Therefore, when the filling material 7 is filled in the resin case 2, the air in the resin case 2 is discharged to the outside from the guide portion 6h, so that the filling material 7 is properly injected into the resin case 2. become.

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

The electrical cord insertion hole 4 of the circuit board 4
The electric cord 8 is inserted through a and the electric cord 8 is soldered to the land portion of the circuit board 4. Then, the circuit board 4 is placed along the guide wall 2b formed in the resin case 2, and the end portion of the circuit board 4 is pressed by a dedicated jig in a state where a predetermined pressure is applied to the second end of the circuit board 4. The contact portion 4c is brought into contact with the end of the guide wall 2b to temporarily fix the position of the magnetic detection element 3 arranged on the circuit board 4 with respect to the resin case 2. Then, the filling material 7 is filled in the resin case 2 and cured to fix the magnetic detection element 3 to the resin case 2. The moving object detector 1 is completed by the above.

In the moving object detector 1 having such a structure, the magnet holder 6 arranged on the circuit board 4 is provided with 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 prevent the deformation of the circuit board 4 due to the stress of the filler 7 and the damage of the electronic component and the occurrence of cracks at soldering points. Becomes Particularly, a predetermined space S is provided 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 by the filler 7, and the stress applied to the front surface and the stress applied to the back surface of the circuit board 4 can be adjusted substantially evenly. Therefore, the design and manufacturing process of the moving object detector 1 can be simplified.

In addition, the magnet holder 6 has
The magnet holder 6 can be easily mounted on the circuit board 4 by providing the arm piece 6f for disposing the magnet holder 6 at a predetermined position on the circuit board 4.
Can be arranged at a predetermined position.

Further, by providing the magnet holder 6 with the guide portion 6h for guiding the filling material 7 to the detection surface 2b side in the resin case 2, the filling material 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 parts as those of the above-mentioned embodiment are designated by the same reference numerals and detailed description thereof will be given. I will omit the explanation.

The difference from the above-described embodiment is that, as shown in FIGS. 4 and 5, the second stress that is formed integrally with the magnet holder 6 via the arm piece 6f and is removable from the magnet holder 6 is used. That is, the suppression unit 6i is provided.

In the moving object detector 1, the arrangement position of the magnetic detection element 3 arranged in the resin case 2 varies depending on the shape of the object to be detected. In that case, by changing the arrangement position of the magnetic detection element 3, the stress due to 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, the electronic parts may be damaged or cracks may be generated at soldering points. 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 object to be detected, but in that case, the number of types of the magnet holder 6 increases, the design work becomes complicated, and the cost is reduced. It becomes high.

For the above problems, the magnet holder 6
A first surface formed to face the back surface of the circuit board 4.
6 g of the stress suppressing portion 6 g and the second stress suppressing portion 6 i formed so as to face the surface of the circuit board 4, the stress due to the filler 7 received by the back surface of the circuit board 4 is Of the filling material 7 in the space S1 provided between the stress suppressing portion 6g and the circuit board 4, and the stress due to the filling material 7 that the surface of the circuit board 4 receives is determined by the second stress suppressing portion 6i and the circuit. It is the volume of the filler 7 in the space S2 provided between the substrate 4 and the substrate 4. Therefore, even when the arrangement position of the magnetic detection element 3 is changed depending on the shape of the object to be detected, it is possible to substantially equalize the stresses applied to both surfaces of the circuit board 4 by the filler 7.

Further, in the structure of the resin case 2, if the second stress suppressing portion 6i is not needed due to the position where the magnetic detecting element 3 is arranged, the second stress suppressing portion 6i is removed from the magnet holder 6. Since it becomes possible to dismount and arrange it on the circuit board 4, it is sufficient to prepare only the magnet holder 6 having the second stress suppressing portion 6i.
It becomes better without having to prepare multiple types.

In the embodiment of the present invention, the circuit board 4 is formed with the second contact portion 4c that contacts the resin case 2. However, the guide wall 2b of the resin case 2 is provided with the circuit board. It may be configured to form an abutting portion with respect to No. 4.

Further, in the embodiment of the present invention, the circuit board 4 is placed 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 detection element 3 is placed in the resin case 2. Although it is configured to be temporarily fixed at a predetermined position inside, a convex positioning portion is formed on the peripheral edge portion along the longitudinal direction of the magnet holder 6, and the positioning portion is formed by 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 integrally formed with the magnet holder 6 is detachable from the magnet holder 6; In the present invention described, for example,
The first stress suppressing portion 6g may have a structure similar to that of the second stress suppressing portion 6i, and the first stress suppressing portion 6g may be removable 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, the magnetic detection element for detecting the moving state of the object to be detected is housed in the resin case, and the magnetic detection element is arranged at a predetermined position on the detection surface side of the resin case and the resin case is provided. A moving object detector in which a filling material is filled to hold the magnetic detection element in a resin case, and a circuit board on which the magnetic detection element and other electronic components are arranged,
A magnet for applying a magnetic field to the magnetic detection element, a recess for arranging the magnet, and a circuit board are provided so as to face the circuit board, and are added to the surface of the circuit board by the filler.
Between the stress applied to the back surface of the circuit board and the stress applied to the back surface of the circuit board.
And a magnet holder disposed on the circuit board. The circuit board is deformed due to the stress of the filling material, and the electronic component is damaged. It is possible to prevent the occurrence of cracks at the soldering points and to simplify the design and manufacturing process of the moving object detector.

Further, according to the present invention, a magnetic detection element for detecting the moving state of the object to be detected is housed in a resin case, the magnetic detection element is arranged at a predetermined position on the detection surface side of the resin case, and the resin is used. A moving object detector in which a case is filled with a filling material to hold the magnetic detection element in the resin case, a circuit board on which the magnetic detection element and other electronic parts are arranged, and the magnetic detection element. A magnet that gives a magnetic field to
A concave portion for disposing the magnet, and first and second stress suppressing portions that are provided so as to face both surfaces of the circuit board and that suppress at least the stress of the filler applied to the circuit board, And a magnet holder arranged on the circuit board,
Even when the position of the magnetic detection element in the resin case is changed depending on the shape of the object to be detected, the circuit board is deformed due to the stress of the filling material, the electronic parts are damaged, and cracks occur at soldering points. Can be prevented.

[Brief description of drawings]

FIG. 1 is a sectional view of essential parts showing a moving object detector that is an embodiment of the present invention.

FIG. 2 is a perspective view showing the above-described circuit board and magnet holder.

FIG. 3 is a front view showing the above-mentioned circuit board and magnet holder.

FIG. 4 is a cross-sectional view of essential parts showing a moving object detector that is another embodiment of the present invention.

FIG. 5 is a perspective view showing the same circuit board and magnet holder.

[Explanation of symbols]

1 Moving object detector 2 resin case 3 Magnetic detection element 4 circuit board 5 magnets 6 magnet holder 6f Arm piece (arrangement part) 6g Stress suppression part (first stress suppression part) 6h guidance section 6i Second stress suppressing section 7 Filling material S1 space S2 space

Claims (7)

(57) [Claims] 1. A magnetic detection element for detecting a moving state of an object to be detected is housed in a resin case, the magnetic detection element is arranged at a predetermined position on the detection surface side of the resin case, and is filled in the resin case. A moving object detector which is filled with a material and holds the magnetic detection element in the resin case, wherein a circuit board on which the magnetic detection element and other electronic parts are arranged, and a magnetic field applied to the magnetic detection element A magnet, a recess in which the magnet is disposed, and a surface of the circuit board that is provided so as to face the circuit board and is filled with the filling material.
Applied to the backside of the circuit board
A moving object detector, comprising: a stress holder that adjusts the force and the force substantially uniformly; and a magnet holder that is 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 portion. 3. A magnetic detection element for detecting a moving state of an object to be detected is housed in a resin case, the magnetic detection element is arranged at a predetermined position on the detection surface side of the resin case, and is filled in the resin case. A moving object detector filled with a material to hold the magnetic detection element in the resin case, a circuit board on which the magnetic detection element and other electronic parts are arranged, and a magnetic field applied to the magnetic detection element. A magnet, a recess for arranging the magnet, and first and second stress suppressing portions that are provided so as to face both surfaces of the circuit board and that suppress at least stress due to the filler applied to the circuit board. And a magnet holder disposed on the circuit board, the moving object detector. 4. The moving object detector according to claim 3, wherein predetermined spaces are provided between the circuit board and the first and second stress suppressing portions, respectively. 5. The stress suppressing portion of at least one of the first and second stress suppressing portions is detachably provided from the magnet holder, according to claim 3 or 4. Moving object detector. 6. The magnet holder according to any one of claims 1 to 5, wherein the magnet holder includes an arrangement portion for arranging the magnet holder at a predetermined position on the circuit board. The moving object detector described in. 7. The magnet holder is formed with a guide portion that guides the filling material to the surface to be detected in the resin case, according to any one of claims 1 to 6. Moving object detector.