JP2008010644A - Coil unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent water infiltration into a coil relevant to a coil unit. <P>SOLUTION: A bobbin 10 has a configuration where a holding groove 13 is formed which continuously opens over the all periphery by raising at about a right angle a pair of support 12 from both edges of a main body 11 of circular form, wherein a coil 20 is held in the holding groove 13, and a housing body 30 is molded so as to cover from the opening of the housing groove to the external surface of the support 12. In the annular region covered by the housing body 30 among the external surface of the support 12, a sealer 40 is coated so as to continue over the hoop direction. Even if liquid infiltrates into a clearance between the support 12 and the housing body 30 by capillarity, since the infiltration is blocked by the sealer 40, liquid does not reach the coil 20. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a coil device.

Patent Document 1 discloses a coil device.
This coil device includes a bobbin in which a housing groove is formed on the outer peripheral side, a coil wound in a ring shape and housed in the housing groove, and a housing groove so as not to expose the coil. And an exterior body molded so as to fill the opening.
Japanese Patent Application Laid-Open No. 2004-342761

In the above coil device, the entire bobbin is not covered with the exterior body, but only the minimum area necessary for filling the housing groove is covered with the exterior body on the outer surface of the bobbin. The inner peripheral side portion of the outer surface is exposed. Therefore, there is a concern that the liquid may enter the gap between the side wall and the exterior body due to the capillary phenomenon and reach the coil.
The present invention has been completed based on the above circumstances, and an object thereof is to prevent water from entering a coil.

  As means for achieving the above object, the invention of claim 1 is characterized in that a pair of support portions are raised substantially at right angles from both edges of the circular main body portion so as to continuously open over the entire circumference. A bobbin in a form in which a housing groove is formed, a coil in which a wire is wound in a ring shape a plurality of times, and a coil housed in the housing groove, and from the opening of the housing groove to the outer surface of the support part A coil device including an exterior body molded so as to cover the outer peripheral surface of the support portion, the ring-shaped region covered with the exterior body is continuous in the circumferential direction. It is characterized in that a sealing agent is applied.

  According to a second aspect of the present invention, in the first aspect of the present invention, a seal groove that is continuous in the circumferential direction is formed on the outer surface of the support portion, and the seal agent is applied to the seal groove. Has features.

<Invention of Claim 1>
Since the sealing agent is applied to the ring-shaped region covered with the exterior body in the outer surface of the support portion so as to be continuous over the circumferential direction, the liquid is separated from the exterior body with the support portion by capillary action. Even if it enters the gap, the penetration is blocked by the sealing agent, so that the liquid does not reach the coil.

<Invention of Claim 2>
Since the sealing agent is applied in the seal groove, the sealing agent can be applied accurately at a predetermined position.

<Embodiment 1>
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. The coil device of this embodiment includes a bobbin 10, a coil 20, an exterior body 30, and a sealing agent 40.

  The bobbin 10 is made of a synthetic resin (for example, polyphenylene sulfide (PPS) resin), and rises at a substantially right angle from the cylindrical main body 11 and the edges of both ends in the axial direction of the main body 11 in the radial direction. It consists of a pair of support parts 12 and is shaped to have a “U” -shaped (substantially U-shaped) cross section. The main body 11 has a plate shape that is curved in a circular shape with a dimension in the axial direction larger than a dimension in the radial direction. The support portion 12 has an annular shape concentric with the main body portion 11, and has a plate shape whose plate surface is perpendicular to the axial direction of the bobbin 10. The bobbin 10 is formed with an accommodation groove 13 surrounded by the main body portion 11 and the pair of support portions 12. The housing groove 13 is continuously open over the entire circumference on the outer peripheral surface of the bobbin 10, and the coil 20 is housed in the housing groove 13. The coil 20 is formed in a ring shape by winding a single electric wire around the outer peripheral surface of the main body 11 a plurality of times. In a state before the exterior body 30 described later is molded, the coil 20 is exposed at the opening of the accommodation groove 13.

  The exterior body 30 is made of synthetic resin (for example, polyphenylene sulfide (PPS) resin), and is molded so as to be integrated with the bobbin 10 after the coil 20 is accommodated in the accommodation groove 13. The exterior body 30 is for filling the opening of the receiving groove 13 so that the coil 20 is not exposed, and covers the outer surface of the pair of support parts 12 from the opening of the receiving groove 13. Are formed to have a “U” -shaped (substantially U-shaped) cross section. The opening of the accommodation groove 13 is covered and covered with the exterior body 30 over the whole. On the other hand, with respect to the outer surface of the support portion 12 (the side surface opposite to the inner surface of the housing groove 13), the inner peripheral edge side, that is, the side edge on the side opposite to the housing groove 13 and connected to the main body portion 11 The excluded toric region is covered. That is, the inner peripheral edge side of the outer surface of the support portion 12 (that is, the peripheral edge portion on the side opposite to the housing groove 13 and connected to the main body portion 11) is exposed without being covered with the exterior body 30. Yes. Further, the inner peripheral surface (outer surface) of the main body 11 is also exposed without being covered with the exterior body 30.

  A seal groove 14 is formed on the outer surfaces of the pair of support portions 12. The seal groove 14 is concentric with the bobbin 10 and has a continuous circular shape over the entire circumference. The seal groove 14 is formed in a range of an area covered with the exterior body 30 on the outer surface of the support portion 12. A sealant 40 is applied to the seal groove 14. The sealing agent 40 is made of synthetic resin (for example, silicone rubber), and is applied to the sealing groove 14 in advance before the exterior body 30 is molded. The application amount of the sealing agent 40 is set to such an amount that the sealing agent 40 rises from the outer surface of the support portion 12. Therefore, in a state where the exterior body 30 is molded, a part of the sealing agent 40 bites into the exterior body 30 side. Moreover, the sealing agent 40 is applied over the entire region of the sealing groove 14, in other words, the sealing agent 40 is applied so as to form a continuous ring shape over the entire circumference.

In the present embodiment, since the sealing agent 40 is applied to the ring-shaped region covered with the exterior body 30 in the outer surface of the support portion 12 so as to continue in the circumferential direction, the liquid is caused by capillary action. Even if it enters the gap between the support portion 12 and the exterior body 30, the intrusion is blocked by the sealant 40, so that the liquid does not reach the coil 20.
Moreover, since the sealing agent 40 is applied in the seal groove 14 formed on the outer surface of the support portion 12, the sealing agent 40 can be applied accurately at a predetermined position.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the above embodiment, the seal groove (sealing agent application region) is a concentric circle with the bobbin. However, according to the present invention, the seal groove (sealing agent application region) is a circular shape eccentric to the bobbin. Also good.
(2) In the above embodiment, the seal groove (sealing agent application region) is circular. However, according to the present invention, the seal groove (sealing agent application region) may be non-circular.
(3) In the above embodiment, the seal groove is formed and the sealant is applied in the seal groove. However, according to the present invention, the sealant may be applied without forming the seal groove.
(4) In the above embodiment, the receiving groove is opened to the outer peripheral side, but the present invention can also be applied to a form in which the receiving groove opens in the inner peripheral side or the axial direction of the bobbin.
(5) In the above embodiment, the main body is plate-shaped, but according to the present invention, the main body may be block-shaped.
(6) In the above embodiment, the support portion is plate-shaped, but according to the present invention, the support portion may be block-shaped.

Sectional drawing of the coil apparatus of Embodiment 1. Partial enlarged sectional view

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Bobbin 11 ... Main-body part 12 ... Support part 13 ... Accommodating groove 14 ... Seal groove 20 ... Coil 30 ... Exterior body 40 ... Sealing agent

Claims (2)

A bobbin in a form in which an accommodation groove that continuously opens over the entire circumference is formed by raising a pair of support portions at substantially right angles from both edges of a circular body portion;
A coil wound in a ring shape a plurality of times and housed in the housing groove;
A coil device including an exterior body molded so as to cover the outer surface of the support portion from the opening of the housing groove,
The coil device is characterized in that a sealant is applied to a ring-shaped region covered with the exterior body in the outer surface of the support portion so as to be continuous in the circumferential direction. The coil device according to claim 1, wherein a seal groove continuous in a circumferential direction is formed on an outer surface of the support portion, and the sealant is applied to the seal groove.

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