JP2011047656A - Magnetic sensor and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic sensor and a manufacturing method thereof, capable of suppressing generation of distortion of a shape of an outer housing after it is molded. <P>SOLUTION: The magnetic sensor includes: a magnetism detecting means 2 detecting a magnetism change, a magnet 3 providing magnetic force, a plurality of lead terminals 5 electrically connected with the magnetism detecting means 2, an inner housing 6 in which the lead terminals 5 are insert-molded, an outer housing 7 in which the inner housing 6 is insert-molded, and a sealing member 9 provided on the periphery of the outer housing 7. The inner housing 6 is provided with a similar shaped portion 6e that has a shape similar to the periphery of the outer housing 7 including the sealing member 9. A hole portion 6c in which a coupling portion 5d coupling the lead terminals 5 each other is exposed is formed in a portion other than the similar shaped portion 6e. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a magnetic sensor that detects the movement of an object to be detected (such as a gear) and a method for manufacturing the same.

  Conventionally, various magnetic sensors have been proposed, and for example, disclosed in Patent Document 1. Such a magnetic sensor includes an inner element in which a detection element such as a Hall IC incorporating a magnetism detection means for detecting a change in magnetic force and the magnet, and a plurality of lead terminals electrically connected to the detection element are insert-molded. It has a housing, an outer housing in which the inner housing is insert-molded, and a sealing member such as an O-ring provided on the outer periphery of the outer housing.

  The plurality of lead terminals are formed in a state of being connected to other adjacent lead terminals via a connecting portion, and are inserted into the inner housing by insert molding, and then the connecting portion is cut to form the plurality of leads. It was divided into terminals.

JP 2007-309789 A

  However, in such a magnetic sensor, in order to cut the connecting portion, the inner housing has a recess in which the connecting portion is exposed.

  Since the inner housing is provided with the recess, the thickness of the outer housing becomes non-uniform, and there is a possibility that after molding, there is a problem that distortion occurs due to resin sink marks or the like on the outer shape of the outer housing. . Further, there is a possibility that a problem arises in that the airtightness cannot be secured if the distortion occurs in a portion where a sealing member such as an O-ring that secures the airtightness with the counterpart member to which the magnetic sensor is assembled.

  Accordingly, the present invention focuses on the above-described problems and provides a magnetic sensor capable of suppressing the occurrence of distortion of the shape after molding the outer housing and a method for manufacturing the same.

  In order to achieve the above object, the present invention provides a magnetic detection means for detecting a change in magnetic force, a magnet for generating the magnetic force, a plurality of lead terminals electrically connected to the magnetic detection means, and the lead terminals are inserts. A magnetic sensor comprising a molded inner housing, an outer housing in which the inner housing is insert-molded, and a sealing member provided on an outer periphery of the outer housing, wherein the outer housing is provided with the sealing member. A similar shape portion similar to the outer periphery of the housing is provided, and a hole portion where the connecting portion for connecting the lead terminals is exposed is provided avoiding the similar shape portion.

  Each lead terminal is provided with a positioning hole, and the inner housing is provided with a hole corresponding to the positioning hole so as to avoid the similar shape portion.

  A magnetic detecting means for detecting a change in magnetic force; a magnet for generating the magnetic force; a plurality of lead terminals electrically connected to the magnetic detecting means; an inner housing in which the lead terminals are insert-molded; In a method of manufacturing a magnetic sensor comprising an outer housing in which an inner housing is insert-molded, and a sealing member provided on the outer periphery of the outer housing, the lead terminals connected via a connecting portion are insert-molded to insert the inner After molding the housing, a cutting member is inserted from a hole provided avoiding a similar shape portion similar to the outer periphery of the outer housing provided with the sealing member of the inner housing so that the connecting portion is exposed. An inner housing forming step of cutting the connecting portion, and a shape of the inner housing An outer housing forming step in which the inner housing is insert-molded to mold the outer housing after the steps; and the magnetic detecting means is disposed in the outer housing after the outer housing forming step, and the magnetic detecting means and the lead terminals are connected to each other. And a magnetic detection part forming step for electrical connection.

  Further, each lead terminal is provided with a positioning hole, and the inner housing is provided with a hole corresponding to the positioning hole, and the inner housing forming step includes a positioning pin from the hole when the connecting portion is cut. A lead terminal positioning step of inserting the lead wire so as to reach the positioning hole.

    According to the present invention, it is possible to provide a magnetic sensor that can achieve the intended purpose and can suppress the occurrence of distortion of the shape after molding the outer housing, and a method for manufacturing the same.

The side view of the magnetic sensor of 1st Embodiment of this invention. The side view of the lead terminal of the embodiment. The side view of the inner housing which incorporated the lead terminal of the embodiment. Sectional drawing of the AA line in FIG.

  A magnetic sensor 1 according to a first embodiment of the present invention will be described with reference to the drawings. The magnetic sensor 1 includes magnetic detection means 2, a magnet 3, a circuit board 4, a plurality of lead terminals 5, an inner housing 6, an outer housing 7, a cap member 8, and a sealing member 9. Is.

  The magnetic detection means 2 detects a displacement such as rotation or movement of the detected object. For example, the magnetic detection means 2 converts a change in magnetic force associated with the displacement such as rotation of the detected object such as a Hall element into an electric signal and converts it to an external signal. Is output. The magnetic detection means 2 is mounted on the lower surface of the circuit board 4 in FIG. The magnetic detection means 2 converts a change in magnetic force accompanying the rotation of the detected object into an electric signal and outputs it to the outside via the lead terminal 5.

  In FIG. 1, the magnet 3 is fixed to the upper surface of the circuit board 4 with an adhesive and applies a magnetic force to the magnetic detection means 2. In the present embodiment, the magnetic detection means 2 and the magnet 3 are separated from each other. However, the magnetic detection means 2 and the magnet 3 may be housed and integrated in a package with resin or the like.

  The circuit board 4 is provided with a wiring pattern (not shown) made of a conductive material such as copper on an insulating material such as glass epoxy resin, and is interposed between the magnetic detection means 2 and the lead terminal 5, Both are electrically connected. Reference numeral 4 a denotes an electronic component provided on the circuit board 4.

  It is possible to omit the circuit board 4 by directly electrically connecting the magnetic detection means 2 and the lead terminals 5 and incorporating the electronic components provided on the circuit board 4 in the magnetic detection means 2. .

  The lead terminal 5 is made of metal, is bent, and three lead terminals are provided. One end portion 5a of each lead terminal 5 is electrically connected to the circuit board 4 by solder, and the other end portion 5b is exposed in the connector portion 10 for connecting and transmitting the output from the magnetic detection means 2 to an external device. ing. Each lead terminal 5 is provided with a positioning hole 5c. The positioning hole 5c is a through hole. Further, as shown in FIG. 2, each lead terminal 5 is connected to each other at a connecting portion 5d, and in the manufacturing process, the connecting portion 5d is cut to separate the lead terminals 5. Is.

  The inner housing 6 is made of synthetic resin, and the lead terminals 5 are built in by insert molding.

  The main portion 6 a of the inner housing 6 has a columnar shape, and a cross-sectional shape perpendicular to the longitudinal direction of the lead terminal 5 is circular. Further, a reinforcing portion 6b is provided on the connector portion 10 side of the main portion 6a to prevent deformation of the lead terminal 5 when the connector is attached / detached.

  The main portion 6 a of the inner housing 6 is provided with a hole portion 6 c through which the connecting portion 5 d for connecting the lead terminal 5 is exposed, and a hole portion 6 d corresponding to the positioning hole portion 5 c of each lead terminal 5. The hole 6c is for inserting a cutting member for cutting the connecting portion 5d. The hole 6d is formed when the inner housing 6 is molded by positioning each lead terminal 5.

  The hole 6 c and the hole 6 d are circular in cross section, and are provided so as to penetrate the main part 6 a of the inner housing 6 in a direction perpendicular to the longitudinal direction of the lead terminal 5.

  The inner housing 6 is provided with a similar shape portion 6e similar to the outer periphery where the sealing member 9 of the outer housing 7 is provided. Similar to the main portion 6a, the similar shape portion 6e has a circular cross-sectional shape. Further, the inner housing 6 is provided with a hole 6c and a hole 6d so as to avoid the similar shape portion 6e.

  The outer housing 7 is made of a synthetic resin, and in this embodiment, is made of a light absorbing resin that absorbs laser light. The inner housing 6 is built into the outer housing 7 by insert molding. Moreover, the connector part 10 which a part of lead terminal 5 exposes, and the attachment arm piece 7a are provided integrally.

  Similar to the inner housing 6, the main portion 7 b of the outer housing 7 has a circular cylindrical shape with a cross-sectional shape perpendicular to the longitudinal direction of the lead terminal 5. The main portion 7b is composed of a small-diameter portion 7b1 and a large-diameter portion 7b2 having different diameters, and the small-diameter portion 7b1 is the opposite side of the main portion 6a where the connector portion 10 is provided. In addition, the end portion 7c of the small diameter portion 7b1 is provided with a storage portion 7d formed of a recess. The magnetic detection means 2, the magnet 3, the circuit board 4 and the like are stored in the storage portion 7d. Further, the outer housing 7 includes a contact portion 7e that contacts the cap member 8 around the storage portion 7d. The abutting portion 7e is annular and formed without breaks.

  An annular groove 11 is formed in the large-diameter portion 7b2 of the main portion 7b of the outer housing 7. The groove portion 11 includes two side surfaces 11a and one bottom surface 11b, and the cross-sectional shape along the longitudinal direction of the lead terminal 5 of the groove portion 11 is a U-shape. The cross-sectional shape perpendicular to the longitudinal direction of the lead terminal 5 of the groove 11b of the outer housing 7 is also circular. A sealing member 9 is attached to the groove 11.

  The outer periphery of the outer housing 7 provided with the sealing member 9, that is, the cross-sectional shape perpendicular to the longitudinal direction of the lead terminal 5 on the bottom surface 11 b and the cross-sectional shape of the similar shape portion 6 e of the main portion 6 a of the inner housing 6 are It is a similar shape. And the position of the hole 6c and the hole 6d formed in the inner housing 6 avoids the similar shape part 6e.

  Since the inner housing 6 does not have the concave portion such as the hole 6c or the hole 6d in the similar shape portion 6e, the thickness of the outer housing 7 becomes uniform, and the outer shape of the outer housing 7 is caused by resin sink marks or the like. Generation of distortion can be prevented. In particular, the occurrence of distortion can be prevented and the airtightness can be ensured in the portion where the sealing member 9 that secures the airtightness with the counterpart member to which the magnetic sensor 1 is assembled is provided.

  The cap member 8 is made of a light transmissive resin that transmits laser light. In this embodiment, the cap member 8 has a disk shape. The cap member 8 covers the storage portion 7d.

  The housing 3 and the cap member 8 are fixed by laser welding. The laser passes through the cap member 8 and reaches the contact portion between the contact portion 7e of the housing 3 and the cap member 8, raises the temperature of the contact portion, and melts and fixes the housing 3 and the cap member 8. is there.

  The sealing member 9 is an O-ring made of an elastic material, such as rubber, and ensures airtightness with a counterpart member to which the magnetic sensor 1 is assembled.

  Next, a method for manufacturing the magnetic sensor 1 will be described.

  First, in the inner housing forming step, the lead terminal 5 is built into the inner housing 6 by insert molding.

  Each lead terminal 5 connected via the connecting portion 5d is set in a primary mold. When the lead terminal 5 is set in the primary mold, a positioning pin (not shown) is inserted into the positioning hole 5c to determine the position. Thereafter, the inner housing 6 is molded by insert molding. Then, after molding the inner housing, a cutting member (not shown) is inserted into the hole 6c of the inner housing 6 to cut the connecting portion 5d.

  Further, in the inner housing forming step, when cutting the connecting portion 5d, a lead for positioning the lead terminal 5 by inserting a positioning pin (not shown) from the hole portion 6d so as to reach the positioning hole portion 5c of the lead terminal 5. A terminal positioning step is included.

  Second, in the outer housing forming step, the inner housing 6 is built into the outer housing 7 by insert molding.

  After the inner housing forming step, the inner housing 6 is set in the secondary mold. When the inner housing 6 is set in the secondary mold, a predetermined position of the inner housing 6 is pressed to determine the position. Thereafter, the outer housing 7 is molded by insert molding.

  Thirdly, in the magnetic detection part forming step, the magnetic detection means 2, the magnet 3 and the circuit board 4 are arranged in the storage part 7d provided in the outer housing 7, and the magnetic detection means 2 and each lead terminal 3 are electrically connected. Connect to. In the present embodiment, the electrical connection between the magnetic detection means 2 and each lead terminal 3 is via the circuit board 4, and the magnetic detection means 2 is electrically connected to the circuit board 4 in advance. The lead terminal 3 and the circuit board 4 are electrically connected by soldering, but the magnetic detection means 2 and each lead terminal 3 may be directly electrically connected without the circuit board 4 being interposed. Good.

  Finally, the cap member 4 is fixed to the outer housing 7 in the cap member fixing step. In this step, the cap member 4 is welded to the outer housing 7 using a laser to protect the magnetic detection means 2. The means for fixing the cap member 4 to the outer housing 7 is not limited to laser welding, and for example, the cap member 4 and the outer housing 7 may be welded by applying heat.

  The present invention is applicable to a magnetic sensor that forms a housing by molding.

DESCRIPTION OF SYMBOLS 1 Magnetic sensor 2 Magnetic detection means 3 Magnet 5 Lead terminal 5c Positioning hole part 5d Connection part 6 Inner housing 6c Hole part 6d Hole part 6e Similar shape part 7 Outer housing 8 Cap member 9 Sealing member (O-ring)
11 Groove 11b Bottom

Claims (4)

Magnetic detection means for detecting a change in magnetic force, a magnet for generating the magnetic force, a plurality of lead terminals electrically connected to the magnetic detection means, an inner housing in which the lead terminals are insert-molded, and the inner housing In a magnetic sensor comprising an outer housing formed by insert molding, and a sealing member provided on the outer periphery of the outer housing,
A similar shape portion similar to the outer periphery of the outer housing provided with the sealing member is provided in the inner housing, and a hole portion that exposes a connecting portion that connects the lead terminals is provided avoiding the similar shape portion. Magnetic sensor characterized by the above. The magnetic sensor according to claim 1, wherein a positioning hole is provided in each lead terminal, and a hole corresponding to the positioning hole is provided in the inner housing so as to avoid the similar shape part. Magnetic detection means for detecting a change in magnetic force, a magnet for generating the magnetic force, a plurality of lead terminals electrically connected to the magnetic detection means, an inner housing in which the lead terminals are insert-molded, and the inner housing In a method of manufacturing a magnetic sensor comprising an outer housing formed by insert molding and a sealing member provided on the outer periphery of the outer housing,
Similar to the outer periphery of the outer housing provided with the sealing member of the inner housing so that the connecting portion is exposed after insert molding the lead terminals connected through the connecting portion and molding the inner housing. An inner housing forming step of cutting the connecting portion by inserting a cutting member from a hole provided avoiding a similar shape portion, and insert molding the inner housing after forming the inner housing, and molding the outer housing An outer housing forming step, and a magnetic detection portion forming step of arranging the magnetic detection means in the outer housing after the outer housing forming step and electrically connecting the magnetic detection means and the lead terminals. A method of manufacturing a magnetic sensor. Each lead terminal is provided with a positioning hole, and the inner housing is provided with a hole corresponding to the positioning hole, and the inner housing forming step includes a step of inserting a positioning pin from the hole when the connecting portion is cut. The method of manufacturing a magnetic sensor according to claim 3, further comprising a lead terminal positioning step of inserting the lead terminal so as to reach the positioning hole.

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