JPH0737718A - Sealed molding component included in bobbin and sealing method for the bobbin - Google Patents

Abstract

PURPOSE:To improve the adhesion between a sealing member and a bobbin by forming the bobbin using resin, making the edge of the flange thinner than the base and forming a suppressing part, which engages with the sealing member in the deforming direction, on the external part of the flange. CONSTITUTION:A bobbin 10 is provided with a cylinder 11 at the center and flanges 12 and 12 at both edges, and a coil 13 is wound on the cylinder 11 between the flanges 12 and 12. At the edge of the flange 12, a thin part 12A which is sharper and thinner at the edge is formed. A sealing member 14 encapsulates the bobbin 10 whereupon the coil 13 is wound by seal molding. On the external part of the flange 12, suppressing parts 15 and 15 are provided so as to engage with the free edge of the sealing member 14 and suppress the deformation or warpage of the sealing member due to shrinkage when the sealing member hardens.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is designed to seal a bobbin having a winding, such as a solenoid and various sensors (thermistor, IC temperature sensor, etc.), and protect internal components from external factors. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing molded part for a bobbin and a method for sealing a bobbin.

[0002]

2. Description of the Related Art A conventional solenoid is shown in FIG. 6 as an example of a seal-molded part for enclosing a bobbin. In the figure, the solenoid 1 includes a bobbin 3 having a flange portion around which a coil 2 is wound, and a plunger 4 arranged inside the bobbin 3 as basic components. Then, by supplying an electric current to the coil 3, the plunger 4
It has a structure to move.

Further, in this conventional example, after the sleeves 5 and 6 are applied to the inside of the bobbin 3 and the metal is applied to the outside of the flange portion of the bobbin 3, they are covered with, for example, a thermosetting resin. Resin molding is performed using the molded insulator 7 so that the coil 2 and the bobbin 3 are sealed.

In this embodiment, the plunger 4 is slidably supported in the bobbin axial direction while being biased by the spring 8 in the molded insulator 7 formed inside the sleeves 5 and 6.

[0005]

However, in such a conventional solenoid structure, when a resin bobbin is used as an insert and sealing-molded by a sealing member which is another resin, each resin is melted and cooled. There is a problem that the bobbin and the sealing resin are not sufficiently welded due to a difference in solidifying temperature and a difference in heat shrinkage, resulting in incomplete adhesion between them and insufficient sealing property.

In view of the above, it is an object of the present invention to weld a sealing member and a bobbin at the time of insert molding by melting a part of the molded bobbin again with a molten sealing resin and then cooling and solidifying. In order to achieve the sealing of both, and further improve the adhesion between the sealing member and the bobbin by forming a shape in which the bobbin and the sealing member are fitted or engaged with each other when cooled and solidified. It is an object of the present invention to provide a bobbin-containing encapsulation molding component and a bobbin encapsulation molding method.

[0007]

In order to achieve the above object, a sealing molded part of a bobbin according to the present invention comprises a tubular portion and flange portions provided at both ends of the tubular portion. , Sealing of a bobbin containing a bobbin in which a coil is wound around the tubular portion, and an insulating sealing member which is a resin encapsulating so as to cover the entire bobbin in which the coil is wound In the molded part, the bobbin is molded with resin, the front end of the flange portion has a thinner cross section than the base portion, and the outer position portion of the flange portion is restrained from engaging with the sealing member in its deformation direction. It is characterized in that a part is formed.

Further, according to the method of sealing and forming an inner bobbin according to the present invention, the tip end of the flange portion of the bobbin having the tubular portion and the flange portions provided at both ends of the tubular portion is the base portion. By comparison, a bobbin having a thinner cross-section and a restraining portion formed on the outer position of the flange portion is molded with resin, and a coil is wound around the tubular portion between the flange portions, and the coil is wound. Set the rotated bobbin in the mold,
It is characterized in that a sealing resin is injected into the mold to be cooled and solidified.

[0009]

According to the present invention, by using a thermoplastic resin for the bobbin / sealing material, the reversibility of resin melting (melting ⇔ solidification) is utilized to allow the sealing material to enter the flange tip (sealing). A portion having a small volume is provided so as to be melted by molding. That is, when the same amount of heat of the sealing material is received, this design enables melting and welding of only the tip portion.

In the present invention, since the flange portion of the bobbin is formed in a thin-walled cross-sectional shape with a sharp tip, for example, when encapsulating or sealing the sealing member, The tip of the flange portion is melted by the heat of the injected molten resin, and by cooling and solidifying from that state, welding of the enclosed sealing member and the bobbin occurs at the tip of the flange portion of the bobbin. At the same time, in the process of cooling and solidifying the sealing member after injecting the sealing member, the free end of the sealing member is deformed or warped depending on the difference between the thermal contraction rate of the sealing member and the thermal contraction rate of the bobbin molding material. However, this causes the sealing member and the bobbin to be mechanically brought into close contact with each other by engaging or engaging with the restraining portion formed at the outer position of the flange portion of the bobbin. These adhesions are surely performed at a plurality of places where it is necessary, so that the sealability can be sufficiently secured.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings.

1 to 4 show an embodiment of the present invention. This embodiment is an example in which the present invention is applied to a sealing molded component of a bobbin-containing component which is a component of a solenoid. In the figure, 10 is a bobbin, and a cylindrical portion 11,
The flanges 12 and 12 are provided at both ends, and the coil 13 is wound around the cylindrical portion 11 between the flanges 12 and 12. A thin portion 12A is formed at the tip of the flange 12 so as to be sharply tapered and thin toward the tip, and it is preferable that the thin portion 12A is tapered so as to gradually have a thin cross section. Further, 14 is a sealing member for encapsulating the bobbin 10 around which the coil 13 is wound by encapsulation. In the cylindrical portion 11 of the central portion of the bobbin 10, a portion of the sealing member that is located outside the flange portion 12 is engaged with the free end of the sealing member 14 and contracts due to solidification of the sealing member. Suppression portions 15 and 15 that suppress deformation or warpage are formed. As shown in FIG. 4, the restraining portion 15 has a substantially triangular cross section so as to form an acute-angled space 16 with the base portion of the flange portion 12.

The bobbin 10 is made of a resin commonly referred to as engineering plastic such as polyamide, polybutylene terephthalate, and reinforced polyethylene terephthalate, and is molded into a shape as shown in FIG. 2 by, for example, injection molding. In addition, in the embodiment shown in FIGS. 1 and 3, a part of the flange portion 12 is deformed and the terminal 17 is insert-molded in the portion.

Next, with respect to the bobbin 10 thus formed, the coil 1 is attached to the tubular portion 11 between the flange portions 12 and 12.
3 is wound and the end of the coil 13 is connected to the terminal 17 by caulking or soldering, and then the bobbin 10 is set in a mold (not shown), and a bobbin material suitable for sealing molding is used. Engineering plastic sealing material 14
It is injected into a mold and used as an encapsulation so as to cover the coil 13 wound around the bobbin 10.

When the sealing member 14 is injected, the thin portion 12A at the tip of the flange portion 12 of the bobbin 10 depends on the combination of the bobbin material and the sealing member (mainly the melting point).
Melts, and the sealing member 14 and the bobbin 10 are welded at this portion as described above.

Further, as shown in FIG. 4, a part of the sealing member 14 enclosed so as to cover the outer side of the flange 12 of the bobbin 10 becomes a flat piece 14A, which is cooled and solidified. At this time, for example, when polyamide is used for the bobbin 10 and reinforced polyethylene terephthalate is used for the sealing member 14, the flat plate-shaped portion 14A of the sealing member 14 is fixed at the tip of the flange portion 12 of the bobbin 10 due to contraction of molding. Attempts to deform outwardly as a center. But,
Since the deformable piece 14A of the sealing member 14 is deformed while being enclosed in the acute space 16 between the flange portion 12 of the bobbin 10 and the restraining portion 15, the piece 14A becomes the restraining portion 15. The sealing member 14 and the bobbin 10 act so as to be in close contact with each other at the contact surface of the restraining portion 15 while trying to deform in the engaged state.

A solenoid can be constructed by arranging a plunger, a spring, etc. inside the bobbin 10 in the same manner as in the conventional case, with respect to the sealing molded part of the bobbin encased thus formed.

Next, another embodiment of the present invention is shown in FIG.
In this embodiment, the heat shrinkage rate of the resin forming the bobbin 10 is
This is suitable when the heat shrinkage rate of the sealing member 14 is larger than that. That is, in this embodiment, the restraining portion 15 ′ formed by the protrusion is provided on the outer surface of the flange portion 12 of the bobbin 10 which is the outer position portion, and the restraining portion 15 ′ is provided in the contracting direction of the bobbin 10, that is, the bobbin axial direction. It engages with the piece 14A of the sealing member 14 in the direction orthogonal to each other, and by the engagement, deformation due to the difference in heat shrinkage rate between the sealing member 14 and the bobbin 10 is suppressed, and as a result, they are brought into close contact with each other. . The same parts as those in the previous embodiment are designated by the same reference numerals to avoid redundant description.

[0019]

As is apparent from the above description, according to the present invention, first, when the encapsulation member is encapsulation-molded by using the coil bobbin as an insert, the tip of the flange portion of the bobbin has a thin-walled cross-section. Therefore, the sealing member and the bobbin are melted by the resin as the sealing member in the molten state, and then the sealing member and the bobbin are welded while cooling and solidifying, and secondly, the molding that occurs when one of the sealing member and the bobbin is cooled and solidified. By providing a restraining portion that restrains deformation or warpage due to contraction, the two are further adhered to each other, and it is possible to realize these two kinds of adhesion mechanisms in the encapsulation between the sealing member and the bobbin. it can. Therefore, the sealing member can reliably and stably seal the coil bobbin.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing an embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view showing an example of a bobbin according to an embodiment of the present invention.

FIG. 3 is a partially cutaway perspective view showing another example of the bobbin of the embodiment of the present invention.

FIG. 4 is an enlarged cross-sectional view showing a main part of a bobbin in one embodiment of the present invention.

FIG. 5 is an enlarged sectional view showing a main part of a bobbin in another embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a conventional example.

[Explanation of symbols]

 10 bobbin 11 cylindrical part 12 flange 12A thin part 13 coil 14 sealing member 15, 15 'restraining part

Claims (2)

[Claims] 1. A bobbin having a tubular portion and flange portions provided at both ends of the tubular portion, wherein a coil is wound around the tubular portion, and an entire bobbin around which the coil is wound. In an encapsulation molding part of a bobbin including an insulating encapsulation member which is a resin encapsulating so as to cover the bobbin, the bobbin is formed of resin, and the front end of the flange part has a thinner cross section than the base part. A bobbin-encapsulated molded component, characterized by the fact that a restraining portion that engages with the sealing member in its deformation direction is formed at an outer position of the flange portion. 2. A bobbin having a tubular portion and flange portions provided at both end portions of the tubular portion, wherein a tip portion of the flange portion has a thinner cross section than a base portion, and an outer portion of the flange portion. A bobbin having a restraining portion formed on one side is molded of resin, a coil is wound around the tubular portion between the flange portions, and the bobbin around which the coil is wound is set in a mold. A method for sealing and molding an internal bobbin, which comprises injecting a sealing resin into a mold to solidify by cooling.