JP6645032B2 - Moving object detection device - Google Patents

Description

  The present invention relates to a moving object detection device, and is suitable for, for example, a moving object detection device that detects rotational movement of a detection target such as a metal gear.

  2. Description of the Related Art As a conventional moving object detection device, for example, there is one disclosed in Patent Document 1. The moving object detection device includes a magnetic detection element, a magnet that applies a magnetic field to the magnetic detection element, a substrate that is electrically connected to the magnetic detection element, and the magnet and the substrate, and A case having lead terminals for electrical connection, a cover for covering the magnetic detection element, the magnet, and the substrate; and a fitting part for fitting and fixing the case and the cover to each other. I have.

JP 2011-7670 A

  Further, the moving object detection device described in Patent Literature 1 includes a storage portion for disposing a magnet in a case, the magnet is disposed in the storage portion via a natural curing type adhesive, and In this structure, a substrate having an opening facing a magnet is provided at an opening end, and a lead portion of a magnetic detection element is electrically connected to a land provided around the opening of the substrate. For this reason, when the magnet is pushed into the storage portion, the adhesive that has flowed in advance may run out and adhere to other components, and thus care must be taken.

  For example, the excess adhesive that has overflowed from the storage portion adheres to the mounting portion of the case for supporting the substrate and hardens, and assembling the substrate as it is, a desired clearance such as floating of the substrate cannot be secured, There is a possibility that this may cause a problem such as excessive stress being applied to each component.

  Also, if the excess adhesive between the magnetic sensing element and the magnet reaches and cures as it is, the gap between the magnetic sensing element and the magnet will be irregular, and the magnetic sensing element will tilt and become electrically connected. There is a possibility that a defect or reduction in detection accuracy may be caused.

  Accordingly, an object of the present invention is to provide a moving object detection device that can prevent the occurrence of a defect due to an excess adhesive by focusing on the above-described problem.

The moving object detection device of the present invention,
A magnetic sensing element;
A rectangular parallelepiped magnet that applies a magnetic field to the magnetic detection element,
A substrate electrically connected to the magnetic detection element,
A case in which a cup-shaped storage portion having a bottom portion and a storage wall surrounding the magnet, a mounting portion on which the substrate is mounted, and a space around the storage portion ,
A cover that covers the magnetic detection element, the magnet, and the substrate,
An adhesive member for fixing the magnet in the storage portion , wherein the storage wall of the case has four corners corresponding to corners of side surfaces of the magnet,
At the four corners of the corner, slits are provided at predetermined positions away from the bottom to penetrate from the housing to the space.

The height of the housing wall from said bottom abutting the magnet, at least a part of the housing wall, characterized in that less than the height of the magnet.

Further, a lead terminal for electrically connecting an external device and the substrate is provided,
The case is characterized in that the space is provided between the magnet and the lead terminal.

  ADVANTAGE OF THE INVENTION The moving object detection apparatus of this invention can prevent generation | occurrence | production of the defect by excess adhesive.

FIG. 1 is a cross-sectional view illustrating a moving object detection device according to an embodiment of the present invention. FIG. 2 is a partially exploded perspective view showing the moving object detection device of the embodiment. The top view which shows the board | substrate of embodiment same as the above. The perspective view showing the case of an embodiment same as the above.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, using examples applied to a gear tooth sensor mounted on a vehicle.

  As shown in FIGS. 1 and 2, a moving object detection device 1 of the present invention includes a magnetic detection element 2, a magnet 3, a substrate 4, a lead terminal 5, a case 6, a cover 7, adhesives 8 and 9. And

  The magnetic detection element 2 can use a Hall IC, converts a change in magnetic force accompanying movement of a moving object to be detected into an electric signal, and outputs the electric signal to the outside via the substrate 4 and the lead terminal 5. The magnetic detecting element 2 is mounted on the substrate 4 and is arranged so as to provide a predetermined clearance with the cover 7. In this case, the magnetic sensing element 2 is provided with four lead portions 21 such as a power supply line and a signal line for connecting to the substrate 4 in a substantially rectangular parallelepiped package disposed in the opening 41 of the substrate 4. In addition, a metal gear that transmits the driving force of the vehicle can be applied as the detection target, and the change in the magnetic force from the magnet 3 due to the change in the distance from the uneven surface of the gear teeth is detected.

  The magnet 3 is made of a permanent magnet and has a rectangular parallelepiped shape. The magnet 3 is fixed to the case 6 using an adhesive 8 at a position facing the opening 41 provided in the substrate 4, and applies a magnetic field to the magnetic detection element 2.

  As the substrate 4, a printed wiring board in which a wiring pattern made of a conductive material such as copper is provided on a hard insulating material such as a glass epoxy resin can be applied. This substrate 4 is electrically connected to the magnetic sensing element 2 and the lead terminals 5. As shown in FIG. 3, an electronic component 42 is mounted on the board 4, and the outer diameter of the magnetism detecting element 2 for arranging the magnetism detecting element 2 on the magnet 3 is substantially at the center of the board 4. A large rectangular opening 41 is formed.

  The substrate 4 has the magnetic sensing element 2 disposed in the opening 41, and the opening 41 is provided with a contact portion 43 that is in contact with one side from which the lead portion 21 of the magnetic detecting element 2 is drawn out. The detection element 2 has a gap 41a between the magnetic sensing element 2 and one side facing the one side in a state where one side thereof is in contact with the contact portion 43 of the substrate 4, and the gap 41a is provided in the gap 41a. The excess adhesive 91 of the adhesive 9 that fixes the magnet 3 and the magnet 3 is guided, so that the excess adhesive 91 does not easily spread to the soldering portion between the lead portion 21 of the magnetic sensing element 2 and the land portion 44 of the substrate 4. I have.

  The substrate 4 is fixed on the open end of the case 6 (the portion covered by the cover 7) by soldering to the lead terminals 5 or the like. Further, the substrate 4 is provided with land portions 44 for solder connection of the lead portions 21 of the magnetic detection element 2 fixed on the magnet 3 via the adhesive 9 in the vicinity of the contact portion 43.

  The lead terminal 5 is composed of three bent lead frames, and a main part is built in a case 6. One end 51 of each lead terminal 5 is exposed from a connector section 60 provided on the case 6, and the other end 52 of the lead terminal 5 is electrically connected to the substrate 4 by solder. The connector section 60 connects and transmits the output from the magnetic detection element 2 to an external device.

  The case 6 is a structure body made of synthetic resin and integrally provided with the connector portion 60 by insert molding the lead terminal 5. The case 6 has a concave portion on the opposite side to the connector portion 60, and has a storage portion 63 having a bottom portion 61 for disposing the magnet 3 and a storage wall 62 at substantially the center thereof. The magnet 3 is fixed therein via an adhesive (adhesive member) 8.

  The case 6 is provided with a mounting portion 64 on which the substrate 4 is placed on the open end and a convex portion 64a projecting above the open end for positioning the substrate 4 at three places. Is provided to be lower than the thickness of the substrate 4. On the other hand, the substrate 4 is provided with a concave portion 45 that fits into the convex portion 64a, and the convex portion 64a of the case 6 does not protrude above the mounting surface of the substrate 4 from the concave portion 45. That is, when the board 4 is mounted, the board 4 is formed to have such a size that the protrusions 64a do not protrude. The outer diameter of the substrate 4 is formed to be smaller than the outer circumference of the opening end of the case 6. Note that the substrate 4 can be held via an adhesive applied to the mounting portion 64 of the case 6.

  As shown in FIG. 4, the storage portion 63 of the case 6 is configured such that the adhesive 8 is applied to the bottom portion 61, the magnet 3 is disposed, and the excess adhesive 81 generated when the magnet 3 is disposed is stored in the storage portion 63 of the storage portion 63. Slits 66 are provided in the surrounding space 65 to protrude. The slits 66 are provided at four corners of the storage wall 62 corresponding to the corners of the magnet 3. The slits 66 are formed at predetermined distances from the bottom surface 61 of the storage unit 63 and are formed from four corners toward the opening side (the substrate 4 side). For this reason, since the accommodating part 63 is provided with a cup-shaped part, the magnet 3 can be firmly held by sufficiently interposing the adhesive 8 in this part.

  The detection portion side of the case 6 has a substantially cylindrical shape, and has two annular grooves 10 and 11 formed therein. One groove 10 has a smaller diameter than the other groove 11 and is provided at a position covered by the cover 7 on the magnetic detection element 2 side of the other groove 11. The other groove 11 is provided in the middle of the case 6. O-rings 10a and 11a as sealing members are mounted in the grooves 10 and 11, respectively. The O-ring 10a is for ensuring airtightness when the moving object detection device 1 is attached to a device (not shown).

  The case 6 includes a plurality of protrusions 67 (engaging portions) that form a fitting portion that fits and fixes the case 6 and the cover 7. In this case, the protrusion 67 is provided between the two grooves 10 and 11.

  The cover 7 is made of a resin material, and has a cup shape including a disk-shaped top plate 71 and a cylindrical peripheral wall portion 72. The cover 7 covers the magnetic detection element 2, the magnet 3, and the substrate 4. The cover 7 has a space formed by the case 6 and the cover 7 in which the O-ring 10 a provided in the groove 10 of the case 6 is compressed between the groove 10 of the case 6 and the inside of the peripheral wall 72 of the cover 7. It is sealed so that water and air do not get inside. The cover 7 has an opening 73 corresponding to the protrusion 67 of the case 6.

  As the adhesives 8 and 9, a naturally-curable liquid adhesive can be used, and for example, a polymer-based adhesive that cures with moisture due to moisture or the like can be used. The adhesive 8 flows into the storage section 63 to fix the magnet 3. The adhesive 9 is applied in a separate process after the magnet 3 is housed in the accommodating portion 63 to bond the magnet 3 and the magnetic detection element 2. Further, the same adhesive can be applied to the mounting portion 64 to hold the substrate 4.

  The moving object detection device 1 includes a magnetic detection element 2, a magnet 3 for applying a magnetic field to the magnetic detection element 2, a substrate 4 electrically connected to the magnetic detection element 2, and a storage wall 62 surrounding the magnet 3. A case 6 is provided with a mounting portion 64 on which the substrate 4 is placed, and a cover 7 that covers the magnetic detection element 2, the magnet 3, and the substrate 4. The magnet 3 is provided with an adhesive 8 flowing into the storage wall 62. The case 6 is provided with a space 65 on the outside of the storage wall 62 into which the excess adhesive member 81 can be introduced when the adhesive member 8 becomes excessive.

  Therefore, when the magnet 8 inserted into the storage portion 63 pushes out the adhesive 8 that has flowed in advance, there are places where there is a possibility of affecting the electrical connection such as the substrate 4 and the lead terminals 5, and the magnetic detection. The surplus adhesive 81 can be introduced into the space 65 before the surplus adhesive 81 reaches a location where there is a possibility of a defective structure, such as a bonding surface with the element 2. Therefore, the moving object detection device 1 can prevent the occurrence of a defect due to the surplus adhesive 81.

  The height of the storage wall 62 from the bottom 61 contacting the magnet 3 is smaller than the height of the magnet 3 in at least a part of the storage wall 62, so that the storage wall 62 reaches the magnetic detection element 2 and the substrate 4 side. Since the excess adhesive 81 can be guided to the space 65 outside the storage wall 62 before, the superfluous adhesive 81 from the adhesive 8 can be easily stored by just pushing the magnet 3 in without carefully monitoring the excess adhesive 81. It can be assembled to the part 63.

  The storage wall 62 is provided with a slit portion 66 that penetrates to the space 65, so that the excess adhesive 81 can be removed while securing a large area where the magnet 3 is held by the storage wall 62 via the adhesive member 8. It can be guided to the space 65. By providing the slits 66 at the four corners of the storage wall 62 corresponding to the corners of the side surface of the magnet 3, the surplus adhesive 81 can be efficiently discharged to the outside of the storage wall 62. Since the amount of the adhesive 8 suitable for holding and holding the magnet 3 can be set by the depth of the slit 66, the work of flowing the adhesive 8 into the storage section 63 is also facilitated.

  The case 6 further includes a lead terminal 5 for electrically connecting the magnet 3 and the substrate 4, and the case 6 is provided with a space 65 between the magnet 3 and the lead terminal 5, so that the excess adhesive 8 is 5 can be reached. Further, as in the present embodiment, by providing the space portion 65 on the groove one round so as to further surround the storage wall 62, it is possible to prevent the surplus adhesive 81 from reaching the space portion 65. In addition, since the space 65 is connected all around, the volume of the space 65 (the amount of the surplus adhesive 81) can be uniformly secured.

  Although the present invention has been described by way of example with the configuration of the above-described embodiment, the present invention is not limited to this, and other configurations may be variously modified without departing from the gist of the present invention. Of course, it is possible to improve and change the design.

  The present invention relates to a moving object detection device that detects a moving state of an object such as a metal, and can be applied, for example, as a device that detects a state of a driving component of a vehicle.

DESCRIPTION OF SYMBOLS 1 Moving object detection device 2 Magnetic detection element 21 Lead part 3 Magnet 4 Substrate 41 Opening 41a Gap 42 Electronic component 43 Contact part 44 Land part 45 Depression 5 Lead terminal 51 One end 52 Other end 6 Case 60 Connector part 61 Bottom part 62 Storage wall 63 Storage section 64 Mounting section 64a Convex section 65 Space section 66 Slit section 67 Projection section 7 Cover 71 Top plate 72 Peripheral wall section 73 Opening 8 Adhesive (adhesive member)
9 adhesive 81,91 surplus adhesive 10,11 groove 10a, 11a O-ring

Claims (3)

A magnetic sensing element;
A rectangular parallelepiped magnet that applies a magnetic field to the magnetic detection element,
A substrate electrically connected to the magnetic detection element,
A case in which a cup-shaped storage portion having a bottom portion and a storage wall surrounding the magnet, a mounting portion on which the substrate is mounted, and a space around the storage portion ,
A cover that covers the magnetic detection element, the magnet, and the substrate,
An adhesive member for fixing the magnet in the storage portion , wherein the storage wall of the case has four corners corresponding to corners of side surfaces of the magnet,
A moving object detection device , wherein a slit part penetrating from the storage part to the space part is provided at a position separated from the bottom part by a predetermined distance at the four corners .   The moving object detection device according to claim 1, wherein a height of the storage wall from the bottom that contacts the magnet is smaller than a height dimension of the magnet in at least a part of the storage wall. . A lead terminal for electrically connecting an external device and the substrate;
The moving object detection device according to claim 1, wherein the case includes the space provided between the magnet and the lead terminal.

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