JP2000018966A - Moving body detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure which holds water-tight the lead-out parts of a conductor, is easy to manufacture and superior in productivity and reliability and realizes cost reduction when a case opening is to be realed with a resin molding. SOLUTION: A magnetosensitive element 1 and permanent magnet 2 for applying a magnetic field to the magnetosensitive element are housed in a resin case 10, a resin cover grommet 20 covering an elastic grommet 40 which a conductor 5 for leading electric signals to outside pierces is fitted in the case 10, and the opening 11 of the case 10 and fitting part of the cover grommet 20 are sealed with a sealing resin molding 30 which constitutes a mounting part 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving object detecting device for magnetically detecting the moving state of a non-detecting object that moves linearly or rotationally, such as a rack or a gear made of a soft magnetic material.

[0002]

2. Description of the Related Art In general, a magnetic sensor as a moving object detecting device for detecting a magnetic moving object has a structure in which a magnetic sensitive element such as a Hall IC and a permanent magnet for magnetic bias are housed in a non-magnetic case. . As a specific case structure of a conventional magnetic sensor, as shown in Japanese Utility Model Application Laid-Open No. 6-76864, a magnetic sensitive element, a permanent magnet, an electronic component, and a terminal for outputting an electric signal detected by the magnetic sensitive element to the outside are provided. There is a case in which a sealing member is molded with resin around the opening of the outer case and the entire periphery of the inner case adjacent to the inner case, wherein the sealing member is built in the inner case, the inner case is inserted into the outer case of a bottomed cylindrical body.

[0003]

SUMMARY OF THE INVENTION
In a structure such as No. 76864, in order to derive an electric signal corresponding to a magnetic change detected by the magnetically sensitive element to the outside,
Although a connector portion that serves as an electrical and mechanical connection portion is required, it may be difficult to seal the conductor in a watertight manner and pull it out of the case.

[0004] In addition, although a structure in which the wire harness is drawn out of the case is conceivable, a wire harness using a general soft vinyl chloride-coated wire does not fuse with a molding resin for sealing and cannot be water-tightly sealed. The resin-coated wire that can be kept watertight by welding with the molding resin for sealing is special,
It becomes a very expensive wire harness, leading to an increase in cost.

[0005] Furthermore, in the case where a filling type resin is filled in the case instead of resin molding to maintain the water harness withdrawal portion in a watertight state, a filling operation and a hardening process are required, so that the manufacturing process is required. There is a problem of low work efficiency.

SUMMARY OF THE INVENTION In view of the above, the present invention is capable of keeping the lead-out portion of the conductor watertight even when the opening of the case is sealed with a resin molded product, is easy to manufacture, and has high productivity and reliability. It is an object of the present invention to provide a moving object detection device which is excellent in cost and can reduce cost.

[0007] Other objects and novel features of the present invention will be clarified in embodiments described later.

[0008]

In order to achieve the above object, a moving object detecting device according to the present invention comprises a magnetically sensitive element and a permanent magnet for applying a magnetic field to the magnetically sensitive element, which are housed in a resin case. A resin cover grommet covering the grommet of the elastic body through which a signal is led out to the outside is fitted to the case, and the opening of the case and the fitting portion of the cover grommet are sealed with a resin molding for sealing. The mounting portion is formed by the sealing resin molded body.

[0009] In the moving object detection device, a protruding portion of the conductor protruding outside the grommet may constitute a connector pin. Alternatively, the conductor may be an insulated resin-coated wire drawn through the grommet.

[0010] It is preferable that a sawtooth-shaped cross-section rib orbiting around the outer peripheral portion is formed in a portion of the outer peripheral portion of the case and the cover grommet covered with the sealing resin molded body.

[0011] An engaging portion for engaging with a case-side end surface of the cover grommet may be formed integrally with one end of the grommet. Alternatively, a plate may be provided at a position facing one end of the grommet so as to contact the case-side end surface of the cover grommet, and the conductor may be passed through the grommet by penetrating the plate.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a moving object detecting device according to the present invention will be described below with reference to the drawings.

A first embodiment of the present invention will be described with reference to FIGS. 1 is a side sectional view, FIG. 2 is a side view, FIG. 3 is a front view, and FIG. 4 is an exploded view. In these figures, 1 is a magnetic sensitive element such as a Hall element or a Hall IC, and 2 is a magnetic sensitive element. Apply the required magnetic field (add magnetic bias)
The magnet 1 is a permanent magnet, and the magnetic sensitive element 1 and the permanent magnet 2 are fixed to the substrate 4 by a resin holder 3. The substrate 4 is provided with a signal processing circuit for processing the output of the magnetically sensitive element 1 as necessary. The ends of the conductors 5 bent in an L-shape are connected to the substrate 4. At least two conductors 5 are required, and these conductors 5 are for leading out an electric signal (a signal after signal processing when a signal processing circuit is provided) detected by the magnetically sensitive element 1 to the outside. .

A resin case 10 made of PBT or the like has a cylindrical shape with a bottom and has an opening 11 at one end before resin sealing as shown in FIG.
2 are formed. The notch 12 has a case 10
A resin cover grommet 20 of the same material as that described above is fitted. The cover grommet 20 is made of the same material as the case 10, but is configured as a separate part for the sake of assembly and molding, and is assembled to the case 10 during assembly.
The cover grommet 20 has a tubular shape, and the inner side surface 22 forms a mechanical fitting portion of the connector. The outer peripheral portions of the case 10 and the cover grommet 20 are partially covered with the sealing resin molded body 30, and the portions covered with the sealing resin molded body 30 include annular ribs 13 having a sawtooth cross section. 21 are formed respectively. The rib 13 orbits the outer periphery of the case 10, and the rib 21 orbits the outer periphery of the cover grommet 20.

The grommet 40 is an elastic body such as rubber.
A flange 41 (engaging portion) that engages with the case-side end surface (inner wall surface) of the cover grommet 20 is integrally formed at one end thereof. The conductor 5 is provided in the through hole of the grommet 40.
Are inserted respectively.

The moving object detecting apparatus according to the first embodiment can be assembled in the following procedure. First, as shown in the exploded view of FIG. 4, a conductor 5 is connected to a substrate 4 on which a magnetically sensitive element 1 and a permanent magnet 2 are fixed by a holder 3, and
Is inserted through the elastic grommet 40 in advance. Then, the grommet 40 is fitted (press-fit) inside the resin cover grommet 20.

Next, the substrate 4 in which the magnetically sensitive element 1 and the permanent magnet 2 are integrated by the holder 3 is accommodated in a resin case 10, and a resin cover grommet 20 is fitted into the cutout 12 on the case opening side. I do. As a result, a semi-assembled product before producing the sealing resin molded body 30 by injection molding is completed.

Then, as shown in FIG. 1, the sealing resin molded body 30 is inserted into the semi-assembled product by insert injection molding together with a part of the outer peripheral portion of the resin case 10 and the resin cover grommet 20 to form a case side opening. The secondary molding is performed so as to cover the part 11, and the mounting part 31 extending to the side of the case 10 is formed by the sealing resin molded body 30. As shown in FIG. 3, a bush 33 made of metal or the like for reinforcement around the mounting hole is formed around the mounting hole 32 of the mounting portion 31 at the same time. The molding resin to be used is a resin such as PBT, and is preferably a material that can be welded to the case 10 and the cover grommet 20, particularly the same material.

When the opening 11 of the case 10 is sealed with a resin, pressure is applied in a direction to push the grommet 40 outward from the cover grommet 20.
Since the flange portion 41 is formed in the cover grommet 0, the flange portion 41 is engaged with the case-side end surface of the cover grommet 20 to prevent the grommet 40 from jumping out. In addition, by forming annular ribs 13 and 21 having a sawtooth cross section on the outer peripheral portions of the case 10 and the cover grommet 20, the mounting portion 3 is formed.
At the time of molding the resin molding 1 with the sealing resin molded body 30, at least the sharp tip portions of the annular ribs 13 and 21 are welded to enhance the waterproof effect.

As shown in FIG. 1, the cover grommet 20
The concave portion opened to the outside of the cover grommet 4 is a portion constituting the connector 50 and the inside of the cover grommet 20.
0 of the conductor 5 protruding through the connector pin 5
It functions as 1. Note that the conductor 5 has a cover grommet 20 when the grommet 40 of an elastic body such as rubber is compressed.
Since it has entered the inner circumference, it is held watertight by the grommet 40.

According to the first embodiment, the following effects can be obtained.

(1) Sealing of the opening 11 of the resin case 10 with the sealing resin molding 30 and the cover grommet 20
Of the fitting portion and molding of the mounting portion 31.
Because it is a manufacturing method using the next molding, mass productivity is improved,
It can be manufactured at low cost.

(2) The conductor 5 for leading out an electric signal corresponding to the magnetic change (magnetic field change due to the movement of the magnetic body) detected by the magnetic sensing element 1 is connected to the elastic grommet 40 of rubber or the like. By passing through, water can be prevented from entering from the outside. That is, the grommet 4 of an elastic body such as rubber
Since 0 enters the inner periphery of the cover grommet 20 in a compressed state, the conductor 5 is held watertight by the grommet 40.

(3) A portion of the outer peripheral portion of the resin case 10 and the cover grommet 20 which is covered with the sealing resin molded body 30 is provided with an annular rib 13 having a saw-tooth cross section and orbiting the outer peripheral portion.
Since the mounting portions 31 are formed by using the sealing resin molded body 30, at least the annular ribs 13 and 2 are formed.
As a result, the sharpened tip portion is welded, so that the welding effect at the time of secondary molding is enhanced, and the waterproof effect can be improved.

(4) One end of the grommet 40 has a flange 41 that engages with the case-side end surface of the cover grommet 20.
Are integrally formed, so that the grommet 40 can be prevented from jumping out of the cover grommet 20 during molding of the sealing resin molded body 30. Note that there is no problem when the amount of protrusion of the grommet 40 is small, but when the amount of protrusion is excessive, the portion where the grommet 40 protrudes is not compressed by the cover grommet 20, and the watertight sealing becomes poor. By preventing the grommet 40 from jumping out, the reliability of maintaining the watertightness of the conductor 5 is improved.

A second embodiment of the present invention will be described with reference to FIGS. 5 is a side sectional view, FIG. 6 is a side view, FIG. 7 is a front view, FIG. 8 is a side view before secondary molding of a sealing resin molded body, and FIG. 9 is mounting of a cover grommet and a grommet on a case. FIG. 10 is a plan sectional view of the cover grommet. In the case of the second embodiment,
An elastic grommet, such as rubber, with a wire harness (a connector or terminal provided at the end of the insulated wire) using an insulated wire such as soft vinyl chloride instead of a simple conductor, fitted inside the cover grommet And pulled out.

As shown in FIG. 5, FIG. 9 and FIG. 10, the cover grommet 60 is formed of the same material as the resin case 10 such as PBT in a cylindrical shape.
An annular rib 61 having a sawtooth cross section is formed in a portion covered with
2 are formed at the base end. The distal end opening 63 of the cover grommet 60 is formed somewhat narrower than the inner diameter in order to prevent the grommet 70 fitted inside from jumping out.

The grommet 70 is an elastic body such as rubber.
As shown in FIG. 9, a flange portion 71 (engaging portion) that engages with the case-side end surface of the cover grommet 60 is integrally formed at one end thereof, and fits into the distal end opening 63 of the grommet 70 of FIG. 10 at the other end. A projection 72 is formed. In order to lead an electric signal corresponding to a magnetic change detected by the magnetic sensing element 1 of FIG. 5 to the outside, a through-hole 73 (shown by a dotted line in FIG. 9) of the grommet 70 has an insulating resin-coated wire of a wire harness 80. 81 are respectively inserted. An annular rib 74 is formed on the outer periphery of the grommet 70 as shown in FIG. The annular rib 74 has a function of pressing against the inner peripheral surface of the cover grommet 60 when the grommet 70 is pressed into the inside of the cover grommet 60 to further ensure watertight sealing.

The assembling of the moving object detecting apparatus according to the second embodiment can be performed in the following procedure. First, as shown in the exploded view of FIG. 9, the insulating resin-coated wire 81 of the wire harness 80 is inserted into the through hole 73 of the grommet 70 of the elastic body,
Further, the grommet 70 is fitted (press-fit) inside the resin cover grommet 60. Then, the one in which the insulating resin-coated wire 81 is connected to the substrate 4 in which the magnetically sensitive element 1 and the permanent magnet 2 shown in FIG. 5 are fixed by the holder 3 is stored, and the cutout 12 on the opening 11 side of the case 10 is housed. The fitting portion 62 of the cover grommet 60 is fitted. This allows
As shown in FIG. 8, a semi-assembled product before producing the sealing resin molded body 30 by injection molding is completed.

Thereafter, as shown in FIGS. 5 to 7, the sealing resin molded body 30 is inserted into the outer peripheral portion of the resin case 10 and the resin cover grommet 60 by insert injection molding on the subassembly of FIG. The mounting portion 3 is formed secondarily so as to cover the case-side opening 11 together with the portion, and extends to the side of the case 10.
1 is formed of a sealing resin molded body 30.

When the opening 11 of the case 10 is sealed with a resin, pressure is applied in a direction to push the grommet 70 outward from the cover grommet 60.
Since the flange portion 71 as an engaging portion is formed at the engagement portion 0, the flange portion 71 is engaged with the case-side end surface (inner wall surface) of the cover grommet 60 to prevent the grommet 70 from jumping out. In addition, by forming annular ribs 13 and 61 having a sawtooth cross section on the outer periphery of the case 10 and the cover grommet 60, at least when the mounting portion 31 is molded with the sealing resin molded body 30. The pointed tip portions of the annular ribs 13 and 61 are welded to enhance the waterproof effect. Each insulating resin-coated wire 81 of the wire harness 80 is held watertight by the grommet 70 because the elastic grommet 70 such as rubber enters the inner periphery of the cover grommet 60 in a compressed state.

Other configurations are the same as those of the first embodiment described above, and the same or corresponding portions are denoted by the same reference characters and description thereof is omitted.

In the case of the second embodiment, the insulating resin-coated wire 81 of the wire harness 80 is made of a general soft vinyl chloride coating or the like, and is made of a material that does not adhere to the molding resin of the sealing resin molded body 30. Also, the insulating resin-coated wire 81 is held watertight by the grommet 70 because the grommet 70 which is an elastic body such as rubber enters the inner periphery of the cover grommet 60 in a compressed state. The wire harness 80 using an inexpensive soft vinyl chloride coating or the like can be used, and the cost can be reduced. Other functions and effects are the same as those of the first embodiment.

FIGS. 11 and 12 show a third embodiment of the present invention. FIG. 11 is a side sectional view, and FIG. 12 is an exploded view of main components. In this case, instead of forming a flange portion at one end of the grommet 70A, a plate member 90 that receives pressure during secondary molding and prevents the grommet 70A from projecting from the cover grommet 60 is provided. The plate material 90 is preferably a metal plate such as an iron plate, but may be a resin plate. A through hole 91 is formed in the plate member 90 to allow the insulating resin-coated wire 81 of the wire harness 80 to pass therethrough.
After inserting the insulating resin covered wire 81, the cover grommet 6
0 is arranged so as to contact the case side end face. Other configurations are the same as those of the above-described second embodiment, and the same or corresponding portions are denoted by the same reference characters and description thereof is omitted.

In this case, when the opening 11 of the case 10 is sealed with a resin, a pressure is generated in a direction in which the grommet 70A is pushed outward from the cover grommet 60, and this pressure is applied to the case-side end surface of the cover grommet 60. The grommet 70 can be prevented from jumping out because the grommet 70 is received by the plate members 90 arranged in contact with each other. Other functions and effects are the same as those of the above-described second embodiment.

In each embodiment, the material of the resin case and the resin cover grommet can be appropriately changed as long as the resin molded body for sealing is welded, and the outer shape can also be changed according to the application. It is. However, it is preferable to provide a convex portion 95 as shown in FIG. 8 on the opening side of the resin case and the resin cover grommet so that the opening can be sealed simultaneously with the formation of the mounting portion. Because of the presence of the projections 95, the resin flows smoothly in the molding die.

Although the embodiments of the present invention have been described above, it is obvious to those skilled in the art that the present invention is not limited to the embodiments and that various modifications and changes can be made within the scope of the claims. There will be.

[0038]

As described above, according to the moving object detecting device of the present invention, the magnetically sensitive element and the permanent magnet for applying a magnetic field to the magnetically sensitive element are housed in the resin case, and the electric signal is externally transmitted. A resin cover grommet that covers the grommet of the elastic body that passes through the conductor led out to the case is fitted to the case, and the opening of the case and the fitting part of the cover grommet are sealed with a sealing resin molded body. The mounting portion is formed by the sealing resin molded body, and by adopting a manufacturing method using secondary molding, mass productivity can be improved. In addition, the waterproofing of the portion of the conductor drawn out of the case can be reliably maintained, and a waterproof effect can be obtained even with an inexpensive wire harness of an insulated wire such as a general soft vinyl chloride, so that the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a first embodiment of a moving object detection device according to the present invention.

FIG. 2 is a side view of the same.

FIG. 3 is a front view of the same.

FIG. 4 is an exploded view showing a main part configuration of the first embodiment.

FIG. 5 is a side sectional view showing a second embodiment of the present invention.

FIG. 6 is a side view of the same.

FIG. 7 is a front view of the same.

FIG. 8 is a side view before molding a sealing resin molded body of a second embodiment.

FIG. 9 is an exploded view showing a main part configuration of the second embodiment.

FIG. 10 is a plan sectional view of a cover grommet used in the second embodiment.

FIG. 11 is a side sectional view showing a third embodiment of the present invention.

FIG. 12 is an exploded view showing a main part configuration of a third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic sensing element 2 Permanent magnet 3 Holder 4 Substrate 5 Conductor 10 Resin case 11 Opening 12 Notch 13, 21, 61 Rib 20, 60 Resin cover grommet 30 Sealing resin molding 31 Mounting part 40, 70, 70A Grommet 41, 71 Flange 50 Connector 51 Connector Pin 62 Fitting 63 Tip Opening 72 Convex 73 Through Hole 80 Wire Harness 81 Insulating Resin Coated Wire 90 Plate 95 Convex

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takatoshi Oyama 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDC Corporation F term (reference) 2F077 AA41 JJ08

Claims (6)

[Claims] 1. A resin cover grommet for enclosing a magnetic sensitive element and a permanent magnet for applying a magnetic field to the magnetic sensitive element in a resin case, and covering an elastic grommet through a conductor for leading an electric signal to the outside. It is fitted to the case, and an opening of the case and a fitting portion of the cover grommet are sealed with a sealing resin molded body, and an attachment portion is formed by the sealing resin molded body. Moving object detection device. 2. The moving object detection device according to claim 1, wherein a protruding portion of the conductor protruding outside the grommet forms a connector pin. 3. The moving object detection device according to claim 1, wherein the conductor is an insulating resin-coated wire that extends through the grommet. 4. A saw-toothed cross-section rib orbiting around the outer peripheral portion is formed on a portion of the outer peripheral portion of the case and the cover grommet which is covered with the sealing resin molded body. Moving object detection device. 5. The moving object detection device according to claim 1, wherein an engaging portion that engages with a case-side end surface of the cover grommet is formed integrally with one end of the grommet. 6. A plate member is provided at a position facing one end of the grommet so as to contact the case-side end surface of the cover grommet, and the conductor is passed through the grommet by penetrating the plate member. , 3 or 4.