JP2977425B2 - Electromagnetic rotation sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic rotation sensor suitable for use as, for example, a crank angle sensor for detecting the rotation speed of an automobile engine.

[0002]

2. Description of the Related Art FIGS. 8 and 13 show a conventional electromagnetic rotation sensor.

[0003] In the drawings, reference numeral 1 denotes a casing of an electromagnetic rotation sensor formed in a closed cylindrical shape by injection-molding an insulating resin material (for example, PBT (polybutylene terephthalate)). A coil bobbin accommodating portion 2 extending in the direction, a connector portion 3 located on the upper end side of the coil bobbin accommodating portion 2 and protruding radially outward, And a mounting portion 4 formed at the bottom. Further, a coil bobbin housing chamber 5 is formed in the coil bobbin housing section 2, and an annular closing section 6 which projects radially inward and closes the coil bobbin housing chamber 5 is formed at a lower end side of the coil bobbin housing section 2. ing. Further, a resin is injected into the inner peripheral end of the closing portion 6 so that the small-diameter portion 11B of the core member 11, which will be described later, is protruded in a liquid-tight manner in a state where the small-diameter portion 11B protrudes therefrom. The projection hole 6A is provided. The mounting portion 4 is mounted via, for example, a bracket in an engine room (both are not shown).

[0004] 7 is provided in the coil bobbin accommodating chamber 5,
FIG. 11 shows an example in which an insulating primary resin material (for example, PBT (polybutylene terephthalate)) is injection-molded.
The coil bobbin 7 is formed as follows. The coil bobbin 7 includes an accommodation cylinder portion 8 as a cylindrical magnet accommodation portion which is located on the upper side and extends vertically and a lower portion of the accommodation cylinder portion 8. And a coil bobbin main body 9 serving as a coil winding portion integrally formed at a position shown in FIG. It is disposed in the rod holding hole 8A so as to penetrate in the vertical direction. Further, the coil bobbin main body 9 includes an upper flange 9A formed so as to protrude radially inward from a lower end side of the housing cylindrical portion 8, and an upper flange 9A.
A winding cylinder portion 9C extending downward from the inner peripheral end side and having a through hole 9B inside, and a lower flange portion 9D protruding radially outward from the lower end side of the winding cylinder portion 9C. The detection coil 13 to be described later is wound around the outer periphery of the winding cylinder 9C (see FIGS. 9 and 10).

[0005] Reference numeral 10 denotes a permanent magnet provided in the accommodating cylinder portion 8 and formed in a short columnar shape. The permanent magnet 10 is formed of a magnet material such as iron or ferrite.

Reference numeral 11 denotes a stepped cylindrical member made of a magnetic material such as electromagnetic soft iron. The core member 11 is located on the base end side, and the back side contacts the lower end side of the permanent magnet 10. A large-diameter portion 11A and a small-diameter portion 11B coaxially extending from the large-diameter portion 11A and inserted into the through hole 9B of the coil bobbin main body 9. The core member 11 positions the large-diameter portion 11A in the housing cylinder portion 8 and abuts the lower surface of the large-diameter portion 11A against the upper flange 9A of the coil bobbin body 9 for positioning. As a result, the distal end surface 11C of the small diameter portion 11B slightly projects outside through the core projecting hole 6A of the closing portion 6. In addition,
When used as an electromagnetic rotation sensor, the core member 11 is disposed at a small distance from the outer peripheral side of a rotating plate (not shown) in which the distal end surface 11C of the small diameter portion 11B is formed of a magnetic material into a toothed disk shape. Position.

[0007] Reference numeral 12 denotes a permanent magnet 1 located in the accommodating cylinder portion 8.
0 shows an iron core member provided in contact with the upper end surface of the permanent magnet 10, and the iron core member 12 is formed in a long cylindrical shape by a magnetic material such as electromagnetic soft iron, thereby increasing the magnetic flux density of the permanent magnet 10. I have.

Reference numeral 13 denotes a detection coil which is located on the outer peripheral side of the small diameter portion 11B of the core member 11 and is provided by winding a coil around the outer periphery of a winding cylinder 9C of the coil bobbin main body 9. The detection coil 13 will be described later. The output terminal 14 is connected to a control unit (neither is shown) via a lead wire or the like. The detection coil 13 generates an induced electromotive force by electromagnetic induction when the rotating plate made of a magnetic material rotates and the magnetic flux from the permanent magnet 10 that passes through the core member 11 changes. The rotation signal of the plate is output to the control unit.

Reference numeral 14 denotes a pair of output terminals provided from the connector portion 4 to the housing cylinder 8 and formed in a substantially L-shape from a conductive material. And a terminal rod 15 extending upward and downward from the upper end surface of the housing cylinder 8 and a terminal rod
5 and a pair of output terminals 16 (only one of which is shown) whose distal end extends radially outward from the upper end of the connecting portion 16A and projects into the connector portion 3. The lower end of the terminal rod 15 is connected to the detection coil 13.

The electromagnetic rotation sensor according to the prior art has the above-described configuration. Next, the manufacturing procedure will be described with reference to FIGS.

First, a coil bobbin 7 is formed from an insulating primary resin material by injection molding using a primary resin mold as shown in FIG.

Next, as shown in FIG. 12, the terminal rod 15 is held in the rod holding hole 8A of the housing tube portion 8, and the detection coil 13 is wound around the winding tube portion 9C of the coil bobbin body 9. The core member 11, the permanent magnet 10, and the iron core member 12 are inserted into the portion 8. Further, the output terminal 16 is fixed to the terminal rod 15 via the connection portion 16A. Thereafter, the chucking member 17 chucks the outer peripheral surface of the portion where the small diameter portion 11B of the core member 11 protrudes from the tip of the winding tube 9C at a position separated from the tip of the winding tube 9C. Then, in this state, it is inserted into a mold (not shown), and the chucking member 17 and the output terminal 16 are positioned and held in the mold.

Then, as shown in FIG.
The casing 1 is formed by forming the coil bobbin accommodating portion 2 for holding the coil bobbin 7, the connector portion 3, and the mounting portion 4 by a secondary resin mold using a secondary resin material, thereby manufacturing an electromagnetic rotation sensor.

Next, when the electromagnetic rotation sensor manufactured as described above is used as a crank angle sensor for an automobile engine, the rotation plate rotates integrally with a crankshaft (not shown) when the engine is started. Then, the teeth of the rotating plate made of a magnetic material sequentially approach the distal end surface 11C of the core member 11,
As a result, the magnetic flux passing through the core member 11 from the permanent magnet 10 changes, and an induced electromotive force is generated in the detection coil 13 by the electromagnetic induction. The electromotive force is output to the control unit via the output terminal 14 or the like as a detection signal that increases or decreases in accordance with the approach or separation of the teeth of the rotating plate, and is used as a crank angle signal for detecting the engine speed.

[0015]

In the above-described conventional electromagnetic rotation sensor, the coil bobbin 7 is formed by primary resin molding, and the permanent magnet 10, the core member 11, the detection coil 13 and the like are formed on the coil bobbin 7. The casing 1 is formed by injection molding with a secondary resin mold so as to enclose them in the assembled state. This allows
Core projecting hole 6A of closing portion 6 and small diameter portion 11 of core member 11
B and the like are brought into liquid-tight contact with each other to prevent rainwater or the like from entering the casing 1 from the outside.

However, since the closing portion 6 is formed to be thin and the electromagnetic rotation sensor is attached to a place where it is always vibrated, such as an engine, the vibration causes the core projection hole 6A and the small diameter portion to be attached. 11B, rainwater or the like is easily formed between the through hole 9B of the coil bobbin main body 9 and the small diameter portion 11B of the core member 11, and between the permanent magnet 10, the iron core member 12, and the housing cylinder portion 8. In some cases, the liquid may enter the upper end side of the coil bobbin 7 through the gap with the peripheral side and reach each output terminal 14 through the upper end surface side of the housing cylinder 8.

As a result, a short circuit occurs between the output terminals 14 due to rain water or the like, and an erroneous signal is output due to the short circuit, thereby causing a problem that reliability is greatly reduced.

Prior to performing the secondary resin molding, the core member 1 protruding from the winding cylinder portion 9C of the coil bobbin main body 9 is formed.
Since the small diameter portion 11 </ b> B is chucked by the chucking member 17, the core member 11 always projects from the closing portion 6 of the coil bobbin housing portion 2.

Therefore, from the viewpoint of the manufacturing process, the closing portion 6
Between the core member 11 and the small diameter portion 11B of the core member 11.
A is always formed. For this reason, a gap is easily formed between the core protruding hole 6A and the small diameter portion 11B, and there is a problem that infiltration of rainwater or the like cannot be avoided.

On the other hand, since the coil bobbin accommodating portion 2, the connector portion 3 and the mounting portion 4 of the casing 1 are formed by the secondary resin mold, the electromagnetic rotation manufactured by the shape of the mold of the secondary resin mold. The type of sensor is determined. For this reason, when changing the shape, mounting part, etc. of the electromagnetic rotation sensor according to the type of vehicle
(When changing the positional relationship between the connector part 3 and the mounting part 4)
In this case, the mold for the secondary resin mold that forms the entire casing 1 must be largely changed, which makes it difficult not only to make manufacturing changes easily, but also increases the cost because there are few common parts. There is a problem.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the prior art, and provides an electromagnetic rotation sensor that prevents a short circuit from occurring due to rainwater or the like and that can easily be changed in design. With the goal.

[0022]

SUMMARY OF THE INVENTION An electromagnetic rotation sensor according to the present invention is provided with a casing formed on one side as a coil bobbin accommodating section and the other side as a connector section and a mounting section, provided inside the casing, and one side formed on the casing. A coil bobbin having a coil winding portion and the other side being a magnet housing portion; a permanent magnet provided in the magnet housing portion of the coil bobbin; and a base end located in the magnet housing portion of the coil bobbin and abutting against the permanent magnet. Then, a core member having a distal end projecting from the coil bobbin accommodating portion via the coil winding portion of the coil bobbin, and a detection coil wound around the coil winding portion of the coil bobbin.

The feature of the configuration adopted by the present invention to solve the above-mentioned problems is that the coil winding part and the magnet
Core together with the coil bobbin consisting of a housing part is formed by the primary resin molded, for winding the detection coil in the coil winding part of the coil bobbin accommodating portion of the casing
A portion covering the coil winding portion in a state where the member is accommodated is formed by a secondary resin mold, and a permanent magnet is accommodated in a magnet accommodating portion of the coil bobbin accommodating portion of the casing.
Portion in a state covering the magnet housing section, in that it has formed by tertiary resin molding the connector portion and the mounting portion.

The coil bobbin has a coil bobbin.
The protruding part that is located on the tip side of the
It is desirable to form a number of positioning projections .

Further, the distal end side of the coil bobbin housing portion
Between the end of the core member and the tip of the positioning projection.
It is desirable to form a covering closure .

[0026]

[Action] With the above structure, to form a coil bobbin by the primary resin molding core member to the coil bobbin, after mounting the detection coil is formed by a secondary resin molded to a portion covering the coil winding part of the coil bobbin. Then, a permanent magnet is placed in the magnet housing by the tertiary resin mold.
A part that covers the magnet housing part of the coil bobbin in the housed state ,
The electromagnetic rotation sensor is manufactured by forming the connector portion and the attachment portion. At this time, the part up to the secondary resin mold can be used as a common part, and the tertiary resin mold can be formed into a shape corresponding to each vehicle type.

In addition, a plurality of positioning operations are performed during the secondary resin molding.
So that the protrusion contacts the bottom of the mold.
Can be positioned. In this state,
By pouring the secondary resin material, the tip of the core member
The side can be covered with a secondary resin material.

Further, the tip side of the coil bobbin accommodating portion and the position
Between the tip of the positioning projection and the tip of the core member
By forming the closing part, the core member is exposed to the outside.
To prevent rainwater or the like from entering from the tip side of the core member .

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the embodiment, the same components as those in the prior art shown in FIGS. 8 to 13 are denoted by the same reference numerals, and description thereof will be omitted.

In the figure, reference numeral 21 denotes a casing according to the present embodiment. The casing 21 is formed in the same manner as the casing 1 shown in FIG. 8 of the prior art, and has a coil bobbin accommodating portion 22 extending vertically, and a coil bobbin accommodating portion. Part 22
A coil bobbin housing chamber 24 is formed in the coil bobbin housing portion 22, though the connector body 23 and the mounting portion (not shown) are formed in a separate process from the above, and a lower end of the coil bobbin housing portion 22 is formed. On the side, a closing portion 25 projecting radially inward and closing the coil bobbin accommodating chamber 24 is formed, and the closing portion 25 covers the distal end surface 11C of the core member 11.

In this embodiment, the casing 2
1 is formed by a two-step resin mold, so that a coil bobbin main body 30 of a coil bobbin 28 described later
Is a secondary resin molded part 26 formed by a secondary resin mold, and the remaining part of the secondary resin molded part 26 of the casing 21 (the part covering the housing cylinder part 29), the connector part 23 The mounting part is a tertiary resin mold part 27 formed by a tertiary resin mold. In addition, the resin mold parts 26 and 27
Is connected to the annular convex portion 2 of the secondary resin mold portion 26.
6A and the annular convex portion 27A of the tertiary resin mold portion 27 are integrally welded in a fitted state.

Numeral 28 is provided in the coil bobbin accommodating portion 22, and becomes a primary resin molded portion according to the present embodiment formed as shown in FIG. 2 by injection molding of an insulating primary resin material by a primary resin mold. A coil bobbin is shown, and the coil bobbin 28 is a coil bobbin 7 described in the prior art.
And a coil bobbin main body integrally formed at a position below the housing cylinder portion 29 as a cylindrical magnet housing portion which is located above and extends vertically. The housing cylinder portion 29 has a rod holding hole 29A for holding the terminal rod 15 in the vertical direction. Further, the coil bobbin main body 30 includes an upper flange portion 30A, a through hole 30B, a winding cylinder portion 30.
C, a plurality of positioning projections 30E, 30E,... Protruding downward from the lower flange 30D. Are formed.

The electromagnetic rotation sensor according to the present embodiment has the above-described configuration, and its basic operation is not particularly different from that of the prior art.

Here, the manufacturing procedure of the electromagnetic rotation sensor according to the present embodiment will be described with reference to FIGS.

First, as shown in FIG. 2, the coil bobbin 28 is made of a high-flow type insulating primary resin material.
Next, it is formed by injection molding using a resin mold. As a result, the same coil bobbin 28 as that of the related art including the positioning protrusion 30E is formed.

Next, as shown in FIG. 3, the terminal rod 15 is held in the rod holding hole 29A of the accommodation cylinder 29,
The detection coil 1 is mounted on the winding cylinder 30C of the coil bobbin main body 30.
3 and the core member 11 is inserted into the housing cylinder portion 29. At this time, the relationship between the length d1 of the positioning protrusion 30E of the coil bobbin 28 and the protrusion d2 of the core member 11 protruding from the lower flange 30D of the coil bobbin main body 30 is as follows.

[0037]

## EQU1 ## d1> d2.

Thereafter, the outer peripheral surface of the housing cylinder portion 29 is chucked by the chucking member 31, and at this time, the core member 11 is pressed by the pressing portion 31A of the chucking member 31.
Is pressed downward to prevent the core member 11 from being displaced. An annular portion 31B is formed below the chucking member 31 so that a secondary resin material is poured during a secondary resin molding described later to form an annular convex portion 26A of the secondary resin molded portion 26. It has become.

The chucking member 31 is inserted into a mold (not shown) while being chucked by the chucking member 31 so that the positioning projections 30E formed on the coil bobbin main body 30 abut on the bottom of the mold. After positioning the base material 31, a highly fluid type insulating resin material having a melting point t1 (for example, 205 ° C.) (for example, PBT (polybutylene terephthalate)) is formed at a molding temperature T1 (for example, 255 ° C.). The secondary resin mold part 26 is molded.

As a result, as shown in FIG. 4, a secondary resin mold portion 26 for holding a portion of the coil bobbin main body 30 of the coil bobbin 28 is formed by a secondary resin mold. At this time, since the positioning projections 30E having the relationship shown in Equation 1 above are formed on the distal end side of the coil bobbin main body 30, the distal end surface 11A of the core member 11 is closed
5 does not protrude.

Further, the mold and the chucking member 31
5, the output terminal 16 is fixed to the terminal rod 15 via the connecting portion 16A, and the permanent magnet 10 and the core member 1 are accommodated in the accommodating cylindrical portion 29, as shown in FIG.
Insert 2. Then, the outer peripheral surface of the secondary resin mold part 26 is chucked by the chucking member 31.
At this time, the upper surface of the chucking member 31 is made flush with the bottom surface of the annular convex portion 26A of the secondary resin mold portion 26.

In this state, after being inserted into a mold (not shown) and positioned, a melting point t2 (for example, 20
A tertiary resin material (for example, PBT (polybutylene terephthalate)) having an insulating property of a normal fluid type having a temperature of 5 ° C.) is poured at a molding temperature T2 (for example, 270 ° C.), and the tertiary resin mold portion 27 (coil bobbin 28 (The portion covering the housing cylinder portion 29, the connector portion 23, and the mounting portion).

As a result, as shown in FIG. 6, the casing 21 that completely covers the coil bobbin 28 is formed. At this time, the molding temperature T2 (27
0 ° C.) is performed at a temperature higher than the melting point t 1 (205 ° C.) of the secondary resin material by 60 ° C. or more, so that the annular convex portions 26A and 27A serving as the boundary surfaces have the annular shape of the secondary resin mold portion 26. The annular convex portion 27A of the tertiary resin mold portion 27 is formed so as to be welded to the convex portion 26A, and is integrated with the annular convex portions 26A, 27A.

In the present embodiment, however, the casing 21 is made up of the secondary resin mold portion 26 covering the coil bobbin main body 30 of the coil bobbin 28, and the housing cylinder portion 29 of the coil bobbin 28.
, A connector portion 23 and a tertiary resin mold portion 27 serving as an attachment portion. However, by setting the molding temperature T2 at the time of the tertiary resin molding to be higher than the melting point t1 of the secondary resin material used for the secondary resin mold by 60 ° C. or more, the annular convex portion serving as the boundary surface between the resin mold portions 26 and 27 is formed. 26A and 27A can be integrally welded and bonded in a state of being in close contact with each other.
8 can be completely prevented from entering rainwater or the like.

In this embodiment, since the core member 11 does not protrude from the closed portion 25 of the casing 21, the core protruding hole 6A does not exist as in the prior art. Infiltration of rainwater or the like completely disappears.

Accordingly, the casing 21 is constituted by the coil bobbin 28 and the secondary resin mold section 26 and the tertiary resin mold section 27, and the coil bobbin 28 and the like are formed by the casing 2
By completely sealing the inside of the housing 1, rainwater can be prevented from entering the coil bobbin 28 and the like, and rainwater and the like can be completely prevented from entering each output terminal 14 side. Then, it is possible to reliably prevent a short circuit from occurring in each of the output terminals 14, and to eliminate the output of an erroneous signal, thereby greatly improving the reliability.

Further, the molding temperature of the tertiary resin mold is 2
Since the melting point is higher than the melting point of the secondary resin material used for the secondary resin mold, the boundary surface between the resin mold portions 26 and 27 can be integrally welded, and the infiltration of rainwater or the like can be reliably prevented.

On the other hand, FIG. 7 shows an electromagnetic rotation sensor manufactured when the mold for manufacturing the tertiary resin mold portion 27 is changed. In FIG. 7, reference numeral 41 denotes a tertiary resin mold portion. The tertiary resin mold portion 41 is formed such that a connector portion 42 and a mounting portion 43 are linearly located.

As described above, in the manufacturing process of this embodiment, when changing the shape, size, type of the mounting portion, etc. of the electromagnetic rotation sensor, the tertiary resin molding portion 27 is molded. It is only necessary to change the shape of the mold to a mold for molding the tertiary resin mold part 41, and the shape can be easily changed by using the secondary resin mold part 26 as a common part.

That is, the part manufactured in the manufacturing process up to the secondary resin mold part 26 can be managed as a common part, so only the tertiary resin mold part 27 needs to be changed, and the electromagnetic rotation sensor The number of types can be reduced, and inventory management can be simplified.

Further, also in the manufacturing process, the stage before the tertiary resin molding, that is, the manufacturing process up to the molding of the secondary resin mold portion 26 shown in FIG. In addition, a change in the manufacturing process line due to a change in the type of sensor can be reduced, and the manufacturing cost can be significantly reduced.

In the above embodiment, the shape of the tertiary resin mold portions 27 and 41 formed by the tertiary resin mold is such that the connector portions 23 and 42 and the mounting portion 43 are orthogonal to the secondary resin mold portion 26. However, the present invention is not limited to this, and even if the connector portion and the attaching portion are inclined with respect to the secondary resin mold portion 26, the present invention can be easily manufactured. The electromagnetic rotation sensor having the shape described above can be easily manufactured.

In the above-described embodiment, the crank angle sensor has been described as an example of the electromagnetic rotation sensor. However, the present invention is not limited to this. For example, various electromagnetic sensors such as a rotation sensor for detecting the number of rotations of a wheel may be used. The present invention can also be applied to a rotation sensor.

[0054]

As described in detail above, according to the present invention, the coil bobbin is formed by a primary resin mold, and the detection coil is formed in the coil winding portion of the coil bobbin receiving portion of the casing.
The coil is wound while the core member is housed.
The part covering the winding part is formed by a secondary resin mold, and the magnet housing part of the coil bobbin housing part of the casing is formed.
A portion that covers the magnet housing portion with the permanent magnet housed therein ;
Because the connector portion and mounting portion so as to form the tertiary resin mold, can be formed portion by the secondary resin molding and the common parts, the position of the connector portion and the mounting portion which is formed by tertiary resin mold By changing the relationship, various electromagnetic rotation sensors can be easily manufactured. Furthermore, up to the secondary resin mold can be manufactured as a common part, and by increasing the number of common parts, the manufacturing cost can be significantly reduced.

The coil bobbin has a coil bobbin.
The protruding part that is located on the tip side of the
By forming a number of positioning protrusions , the secondary resin
During positioning, several positioning protrusions will contact the bottom of the mold.
Thus, the coil bobbin can be positioned. Ma
In this state, the secondary resin material is poured into the mold.
Therefore, the tip side of the core member can be covered with the secondary resin material.
Therefore, it is possible to completely prevent rainwater or the like from entering between the core member and the casing, and it is possible to reliably prevent a short circuit from occurring in the output terminal.

Further, the distal end side of the coil bobbin housing portion
Between the end of the core member and the tip of the positioning projection.
The core member and the casing are
Can completely prevent rainwater, etc., from entering between
Can reliably prevent short-circuits in the force terminal.
You.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an electromagnetic rotation sensor according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a coil bobbin formed by a primary resin mold.

FIG. 3 is a longitudinal sectional view showing a state where the coil bobbin in FIG. 2 is chucked by a chucking member and is provided in a secondary resin mold.

4 is a longitudinal sectional view showing a state in which a secondary resin mold is performed in the state of FIG. 3 and a secondary resin mold portion is formed.

FIG. 5 is a longitudinal sectional view showing a state in which the secondary resin mold portion is chucked by a chucking member following the state of FIG. 4 and prepared for a tertiary resin mold.

FIG. 6 is a longitudinal sectional view showing a state in which a tertiary resin mold is performed in the state of FIG. 5 and a tertiary resin mold part is formed to manufacture an electromagnetic rotation sensor.

FIG. 7 is a perspective view of different types of electromagnetic rotation sensors manufactured according to the embodiment.

FIG. 8 is a perspective view showing a conventional electromagnetic rotation sensor.

9 is a longitudinal sectional view showing the electromagnetic rotation sensor in FIG.

FIG. 10 is a side view showing a state where a detection coil is wound around a coil bobbin.

FIG. 11 is a longitudinal sectional view showing a coil bobbin formed by a primary resin mold.

FIG. 12 shows a state in which the tip of the core member inserted into the coil bobbin in FIG.
It is a longitudinal cross-sectional view showing the state provided in the next resin mold.

13 performs a secondary resin mold in the state of FIG. 12,
It is a longitudinal cross-sectional view which shows the state which manufactured the electromagnetic rotation sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Permanent magnet 11 Core member 13 Detection coil 14 Output terminal 21 Casing 23, 42 Connector part 24 Coil bobbin accommodation room 26 Second resin mold part 26A, 27A Annular convex part (boundary surface) 27, 41 Third resin mold part 28 Coil bobbin 29 Housing cylinder part (magnet housing part) 30 Coil bobbin main body (coil winding part) 30E Positioning protrusion 43 Mounting part

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-337466 (JP, A) JP-A-5-231811 (JP, A) JP-A-5-190698 (JP, A) JP-A-5-19086 141910 (JP, A) JP-A-4-289458 (JP, A) JP-A-4-136571 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01P 3/488 G01P 3 / 487

Claims (3)

(57) [Claims] 1. A casing formed on one side as a coil bobbin accommodating section, the other side as a connector section and an attaching section, and provided in the casing, one side as a coil winding section and the other side as a magnet accommodating section. A coil bobbin, and a permanent magnet provided in a magnet housing portion of the coil bobbin,
A core member having a base end located in the magnet housing of the coil bobbin and abutting against the permanent magnet, and a distal end projecting from the coil bobbin housing through the coil winding of the coil bobbin; and a coil winding of the coil bobbin. the electromagnetic rotation sensor comprising a wound on the detection coil, said coil bobbin consisting of the coil winding part and the magnet accommodating portion is formed by the primary resin molded coil turns of the coil bobbin accommodating portion of the casing Detection carp
The coil is wound while the core member is housed.
The part covering the winding part is formed by a secondary resin mold,
Electromagnetic rotation sensor, characterized in that it further portion covering the magnet housing portion in a state of accommodating the permanent magnets in the magnet containing portion of the coil bobbin accommodating portion of the casing, formed by tertiary resin molding the connector part and the mounting part . The method according to claim 2] before Symbol coil bobbin, a coil bobbin Osamu
A plurality of protruding parts that are located on the tip side of the
2. The electromagnetic rotation sensor according to claim 1, wherein a positioning projection is formed. 3. A tip end side and a position of the coil bobbin accommodating portion.
Close the top of the core member between the
The electromagnetic rotation sensor according to claim 2, wherein a closing portion is formed .