JPH11173871A - Electromagnetic induction-type rotation detector and manufacture of the rotation detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately insert-mold the terminal of an electromagnetic induction-type rotation detector into a body with a resin. SOLUTION: With respect to an inside die having a rod-like part forming at least one guide groove axially, at least one terminal 6 comprising a plate- body forming at least one projection part (for example, a cut and raised part 6b) projecting outwardly from one face is engaged so that a face on a counter side to the projection part is abutted on the bottom face of the guid groove of an inside die, and the terminal is resin-molded so that at least the projection part of the terminal is enclosed with the cylindrical part of the inside die as the center, to form a body 5. A coil 3 accommodating at least a core 1 is fit to the body and a winding of the coil is electrically connected to the terminal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic induction type rotation detector and a method of manufacturing the same, and more particularly to a method of manufacturing an electromagnetic induction type rotation detector in which a terminal connected to a coil is formed by insert resin molding in a body.

[0002]

2. Description of the Related Art As an electromagnetic induction type rotation detector, a rotation detector in which a coil is wound around a core is known. For example, Japanese Patent Application Laid-Open No. 8-43416 discloses a method in which a permanent magnet is joined to a base end. There is disclosed an electromagnetic induction type rotation detector in which a coil is wound over the entire length of the core and the tip of the core is arranged so as to face the outer peripheral end surface of the rotating body. In this rotation detector, a pair of terminals is formed by insert resin molding in the body.

Also, Japanese Patent Application Laid-Open No. 63-96512 discloses a method for improving the workability of connection to a terminal. A rotational position detecting device is disclosed in which a starting end and a terminating end of a wire are wound on the connection surface of the body from each terminal so as to be shifted from each other in the axial direction. Also in this device, the terminal is fixed as an insert part during body molding.

[0004]

When the terminal is formed by insert resin molding in the body as in the above-described conventional rotation detector, particularly when the body and the terminal are long, it is difficult to hold the terminal. The terminal may be shifted to be exposed on the outer surface of the body during the molding of the insert resin, or the terminal may be exposed on the outer surface of the body while the terminal is using a rotation detector embedded near the outer surface of the body. In the resin molding process of the body, it is common to insert-mold the terminal while supporting the terminal in the inner mold.However, the terminal may be lifted from the inner mold or may be shifted laterally during the resin molding. Are exposed on the outer surface of the body.

Accordingly, an object of the present invention is to provide an electromagnetic induction type rotation detector having a terminal properly held in a body.

Another object of the present invention is to provide a method of manufacturing a terminal of an electromagnetic induction type rotation detector, which can appropriately insert-mold a terminal into a body.

[0007]

According to a first aspect of the present invention, there is provided a core having a distal end portion opposed to a rotating body, and a coil wound around the core. And forming at least one protrusion projecting outward on one surface of the long plate body, and at least one terminal for electrically connecting the winding of the coil to one end. ,
And a body molded of resin so as to surround at least the projection of the terminal.

[0008] According to a second aspect of the present invention, there are provided the two terminals having substantially the same width, and each of the terminals is formed so that each of the projections protrudes outward from the center of the body. It is good to arrange in parallel.

Further, at least one cut-and-raised portion is formed on the plate forming the terminal, and the cut-and-raised portion projects outward from a center portion of the body. It may be arranged so as to perform.

The manufacturing method according to the present invention includes, as described in claim 4, an inner mold having a rod-shaped portion having at least one guide groove formed in an axial direction. At least one terminal formed of a plate body having at least one protrusion protruding toward the inner mold so that the surface opposite to the protrusion contacts the bottom surface of the guide groove of the inner mold. A resin is formed around the rod-shaped portion of the inner mold so as to surround at least the protruding portion of the terminal to form a body, and a coil accommodating at least a core is mounted on the body, and the coil is formed. Are electrically connected to the terminals.

According to a fifth aspect of the present invention, the two guide grooves are formed on the outer surface of the rod portion of the inner mold so as to be parallel to the axis of the rod portion and have substantially the same width. Preferably, the two terminals are formed to have substantially the same width, and each of the protrusions is arranged so as to protrude outward from the center of the body.

Further, at least one cut-and-raised portion is formed in the plate body forming the terminal, and the surface opposite to the surface from which the cut-and-raised portion protrudes is the inner metal plate. The terminal may be fitted so as to abut the bottom surface of the guide groove of the mold.

[0013]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows an embodiment of an electromagnetic induction type rotation detector according to the present invention, which is used for a crank angle detection device for an internal combustion engine. That is, this electromagnetic induction type rotation detector has a toothed portion TH formed on the outer peripheral end face by a magnetic material as shown by a two-dot chain line in FIG. They are arranged to face each other.

The electromagnetic induction type rotation detector according to the present embodiment comprises a core 1, a permanent magnet 2 joined thereto,
And a bobbin 4 in which a permanent magnet 2 is housed and a coil 3 is wound around the core 1. The core 1 is formed of a magnetic material, for example, an iron-based sintered metal. The core 1 includes a small-diameter circular section 1a and a large-diameter proximal section 1a.
a first tapered portion 1b whose cross-sectional area increases at a first increasing ratio along the axis in the d direction, and a second increasing ratio which is continuous with the first tapered portion 1b and is larger than the first increasing ratio Has a second tapered portion 1c whose cross-sectional area increases, and both tapered portions have substantially the same axial length. The base 1d of the core 1 is formed with a truncated conical recess 1e in the axial direction from the end face thereof, and the thickness of the second tapered portion 1c is substantially uniform.

The permanent magnet 2 is formed as a column having a substantially oval cross section having two notches in the axial direction with respect to the cylinder. The bottom surface of the base end 1d of the core 1 joined to the permanent magnet 2 is also formed in the same shape. On the other hand, the bobbin 4 is a cylindrical body made of a synthetic resin, in which a hollow portion having a small-diameter circular cross section, a tapered hollow portion, and a hollow portion having a large-diameter, substantially oval cross-section are continuously formed. 1 and a permanent magnet 2 are accommodated. The winding of the coil 3 is wound between a pair of flanges integrally formed on the outer peripheral surface of the bobbin 4. The bobbin 4 thus configured is joined to the body 5 as shown in FIG. Although not shown, the body 5a of the bobbin 4 and the body 5 has a so-called snap-fit structure.

As shown in FIGS. 2 to 4, the body 5 has a body portion 5a and a connecting portion 5b formed of synthetic resin in an L-shape, and a flange portion 5f extending in a direction opposite to the connecting portion 5b. I have. The body 5 has a pair of terminals 6,
7, a wire harness 12 connected to these components and a holder 8 for covering these connection portions are formed by insert resin molding. The wire harness 12 is composed of a pair of covered lead wires, which are caulked and connected to one ends of the pair of terminals 6 and 7, and the holder 8 is formed by resin molding, and the connection between the wire harness 12 and the terminals 6 and 7 is covered. Is held. Further, the body 5 is formed by insert resin molding so as to include the terminals 6 and 7, the wire harness 12 and the holder 8.
The other ends of the pair of terminals 6 and 7 are joined to the joints 6a and 7a.
As extended. This molding step will be described later.

The pair of terminals 6 and 7 are long plates made of brass, and cut-and-raised portions 6b and 7b protruding outward are formed on one surface at three places, respectively, and are referred to in the present invention. Protrusions are formed. In the present embodiment, FIGS.
As shown in FIG. 5, the pair of terminals 6 and 7 are formed to have substantially the same width, and are arranged in parallel with each other such that the cut-and-raised portions 6b and 7b protrude outward from the center of the body 5. ing.

As shown in FIG. 1, the bobbin 4 and the main body 5a
The permanent magnet 2 and a part of the bobbin 4 are accommodated in the concave portion, and a spring washer 10 is interposed between the end surface of the core 1 and the bottom surface of the concave portion of the main body 5a. It is pressed in the direction of the tapered portion. A pair of terminals 16 and 17 are fixed to both side surfaces of the main body of the bobbin 4, and the ends of the windings of the coil 3 are wound around each connection portion and soldered. Terminals 16 and 17
Are arranged so as to overlap with the joints 6a, 7a of the terminals 6, 7 respectively when the bobbin 4 and the main body 5a are joined as described above, and both are joined by, for example, projection welding. . Thus, the bobbin 4 and the body 5 are appropriately and reliably joined mechanically and electrically.

Further, a boot 13 made of, for example, rubber is fitted to the end of the connection portion 5b of the body 5, and the boot 13 holds the wire harness 12. And the main body 5
The O-ring 11 is fitted in an annular groove formed on the outer periphery near the opening end of the portion a. And bobbin 4 and body 5
The case 9 is mounted so as to surround the main body 5a. The case 9 is formed into a cylindrical body with a bottom by a non-magnetic rope, and is press-fitted into the outer peripheral surface of the main body 5a, and the end surface of the tip 1a of the core 1 is in contact with the bottom surface. As shown in FIG. 1, the open end of the case 9 is bent inward and locked to the body 5.

Next, a method of manufacturing the above-described electromagnetic induction type rotation detector, in particular, a resin molding step of the body 5 will be described. First, as shown in FIG. 6 to FIG.
7 are arranged in parallel so that the respective cut-and-raised portions 6b and 7b protrude to the opposite side, and a wire harness 12 is caulked to one end of the terminals 6 and 7, and is formed by resin molding so as to cover this joint. The holder 8 is formed. Then, as shown in FIGS. 4 and 5, the pair of terminals 6 and 7 are mounted on the rod-shaped portion 101 of the inner mold 100. Guide grooves (represented by reference numeral 102 in FIG. 4) are formed in both side surfaces of the rod-shaped portion 101 in the axial direction.
The bottom surfaces of the terminals 2 and 7 are fitted so that the opposite surfaces of the raised portions 6b and 7b of the terminals 6 and 7 are in contact with each other. The joints 6a and 7a of the terminals 6 and 7 are inserted into grooves formed in the inner mold 100.

An outer mold (not shown) is arranged so as to include these terminals 6 and 7, the wire harness 12 and the holder 8, and the body 5 is formed by insert resin molding. That is, an outer mold (not shown) that defines the outer shape of the body 5 indicated by a two-dot chain line in FIG. 5 is disposed, and terminals 6 and 6 are positioned from the position indicated by the solid arrow (the molding gate position) above FIG. The synthetic resin is filled so as to surround the cut-and-raised portions 6b, 7b of the base 7. At this time, since the synthetic resin flows as shown by the solid line arrow in the figure, the cut-and-raised portions 6b and 7b act as resistance, and a force is applied to the terminals 6 and 7 in the direction shown by the broken line arrow in the figure. The resins 6 and 7 are cured while being pressed by the inner mold 100. Therefore, there is no possibility that the terminals 6 and 7 are exposed on the outer surface of the body 5. Moreover, since the terminals 6 and 7 are fitted in the guide grooves 102, they do not shift in the lateral direction (the direction perpendicular to the axis) and are fixed in the state shown in FIG.

After the body 5 shown in FIG. 3 is formed as described above and the O-ring 11 is fitted into the annular groove of the main body 5a, the core 1, the permanent magnet 2, the separately formed coil 3, and The bobbin 4 and the spring washer 10 are shown in FIG.
1 and the bobbin 4 and the body 5 are snap-fitted to each other. Then, the case 9 is pressed into the outer peripheral surface of the main body 5a of the body 5, and the open end of the case 9 is bent inward and locked to the main body 5a. Although the boot 13 is fitted to the end of the connecting portion 5b of the body 5, it may be mounted in advance, and the assembling order may be any.

FIG. 9 shows another example of the terminal 6 (similar to the terminal 7). The terminal 6 shown in FIG. 1 has a cut-and-raised portion 6b formed as a convex portion.
A protrusion 6c having a triangular cross section is formed on the terminal 6 in FIG. In the terminal 6 shown in FIG. 1, when the synthetic resin is filled, the resin wraps around the opening of the cut-and-raised portion 6b, while the protrusion 6c shown in FIG. 9 can prevent this wraparound, so that the pressing force is further increased. . In addition, instead of the protrusion 6c,
For example, a similar effect can be obtained by forming a projection 6d shaped like a part of a sphere as shown in FIG.

The operation of the electromagnetic induction type rotation detector constructed as described above will be described. In accordance with the rotation of the rotor RT, air is generated every time the teeth TH face the end face of the tip 1a of the core 1. The gap changes and the magnetic flux distribution changes. As a result, the amount of magnetic flux interlinking with the coil 3 changes, and the output becomes opposite when the rotor RT approaches and separates from the tooth portion TH. An AC voltage corresponding to the rotation is induced and output as a signal indicating the number of rotations.

[0025]

Since the present invention is configured as described above, the following effects can be obtained. That is, in the electromagnetic induction type rotation detector according to claim 1, the terminal is formed by forming at least one convex portion protruding outward on one surface of the long plate. Since the terminal is formed by resin molding so as to surround the portion, the terminal can be appropriately held in the body without being exposed on the outer side surface of the body.

According to a fourth aspect of the present invention, there is provided a method of manufacturing an electromagnetic induction type rotation detector, wherein at least one plate formed of at least one projection protruding outward from one surface is formed. The terminal is fitted so that the surface on the side opposite to the protrusion contacts the bottom surface of the guide groove of the inner mold, and the resin is molded so as to surround at least the protrusion of the terminal centering on the rod-shaped portion of the inner mold. As a result, the terminal can be appropriately formed by insert resin molding in the body.

[Brief description of the drawings]

FIG. 1 is a sectional view of an electromagnetic induction type rotation detector according to an embodiment of the present invention.

FIG. 2 is a plan view of an electromagnetic induction type rotation detector according to one embodiment of the present invention.

FIG. 3 is a sectional view of a body part according to the embodiment of the present invention.

FIG. 4 is a bottom view of a body part according to the embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a step of insert resin molding of a terminal portion at the time of manufacturing the electromagnetic induction type rotation detector according to one embodiment of the present invention.

FIG. 6 is a plan view of a terminal portion according to the embodiment of the present invention.

FIG. 7 is a sectional view of a terminal portion according to the embodiment of the present invention.

FIG. 8 is a side view of a terminal portion according to the embodiment of the present invention.

FIG. 9 is a sectional view showing another example of the terminal according to the embodiment of the present invention.

FIG. 10 is a sectional view showing still another example of the terminal according to the embodiment of the present invention.

FIG. 11 is a sectional view showing an assembled state of the electromagnetic induction type rotation detector according to one embodiment of the present invention.

[Description of Signs] RT rotor (rotating body) 1 core, 2 permanent magnet 3 coil, 4 bobbin, 5 body, 5a main body, 5b connecting portion 6, 7 terminal 6b, 7b cut-and-raised portion 8 holder 9 case 10 spring washer , 11 O-ring 12 wire harness, 13 boots 16, 17 terminal

Claims (6)

[Claims] 1. A core having a distal end portion opposed to a rotating body, a coil wound on the core, and at least one protrusion projecting outward on one surface of a long plate. Electromagnetic induction comprising at least one terminal for electrically connecting the winding of the coil to one end, and a resin-molded body surrounding at least the projection of the terminal. Type rotation detector. 2. The semiconductor device according to claim 1, further comprising: two terminals having substantially the same width, wherein each of the protrusions is arranged in parallel with each other so as to protrude outward from a center of the body. The electromagnetic induction type rotation detector according to claim 1. 3. The apparatus according to claim 1, wherein at least one cut-and-raised portion is formed on the plate forming the terminal, and the cut-and-raised portion is disposed so as to protrude outward from a center portion of the body. The electromagnetic induction type rotation detector according to claim 2 or 3, wherein: 4. An inner mold having a rod-shaped portion having at least one guide groove formed in an axial direction, from a plate having at least one convex portion projecting outward from one surface. At least one terminal is fitted so that the surface on the side opposite to the convex portion contacts the bottom surface of the guide groove of the inner mold, and at least the terminal of the terminal is centered on the rod portion of the inner mold. A body is formed by resin molding so as to surround the protrusion, a coil containing at least a core is mounted on the body, and a winding of the coil is electrically connected to the terminal. Manufacturing method of electromagnetic induction type rotation detector. 5. An outer surface of the rod portion of the inner mold,
The two guide grooves are formed in parallel to the axis of the rod-shaped portion and have substantially the same width, the two terminals are formed to have substantially the same width, and each of the projections extends outward from the center of the body. The method for manufacturing an electromagnetic induction type rotation detector according to claim 4, wherein the detector is disposed so as to protrude. 6. A plate forming the terminal, wherein at least one cut-and-raised portion is formed, and a surface opposite to a surface from which the cut-and-raised portion protrudes abuts a bottom surface of the guide groove of the inner mold. The method for manufacturing an electromagnetic induction type rotation detector according to claim 4, wherein the terminal is fitted as described above.