JPH04257206A - Coil device - Google Patents

Abstract

PURPOSE:To improve sealability against the infiltration of oil and water from outside. CONSTITUTION:The outer faces of collars 10a at both ends of a coil bobbin 10 are provided circumferentially with continuous ringlike ridges 11, 12. A coil 2 is wound between both collars 10a, 10a. Including the outer periphery of both collars 10a, 10a, the outer periphery of the coil 2 is coated with an integral resin molded member 3 which is brought into contact with the ridges 11, 12.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil device used in a solenoid valve, and more particularly to a coil device with improved sealing performance.

0002

2. Description of the Related Art A conventional coil device for this type of use is one in which the entire outer periphery of the coil is covered with a resin molding material in order to prevent external oil or water from coming into contact with the coil made of enamelled wire.

FIG. 4 shows a conventional example of this type of coil device. An annular flange 1a is formed at both ends of the cylindrical coil bobbin 1, and a coil 2 is wound between the flange 1a. The area including the outer periphery of the coil 2 and both flanges 1a is covered with a resin molding material 3.

0004

[Problems to be Solved by the Invention] Incidentally, in the conventional coil device described above, although the entire coil including the flange 1a of the bobbin 1 is covered with the resin molding material 3, the flange 1a
Since the outer surface of the flange 1a is flat, a small gap is created between the outer surface of the flange 1a and the mold material 3 due to the difference in shrinkage rate between the mold material 3 and the material of the bobbin 1 during molding. There was a possibility that oil or water from the outside could enter from there.

[0005] An object of the present invention is to provide a coil device that eliminates such a possibility as much as possible.

[0006]

[Means for Solving the Problems] The coil device of the present invention includes:
A cylindrical coil bobbin with flanges formed at both ends, a coil wound between these two flanges, and a range from the outer periphery of the coil to the outer periphery and outer surface of both flanges covered with an integral molding material, It is characterized in that a ring-shaped recess or protrusion continuous in the circumferential direction is formed on the outer surface of the flange, which is in close contact with the molding material.

[0007]

[Operation] During molding, the ring-shaped concave or convex portion formed on the outer surface of the flange portion and the molding material come into close contact along the shape. At that time, a radial force acts on the contact surface due to the difference in shrinkage rate between the mold material and the bobbin material, but since the concave or convex portion on the outer surface of the collar has a surface that intersects with the radial direction, The mold material and the bobbin are brought into strong pressure contact on either of these surfaces due to the radial force. Therefore, even if a small gap is created between the outer surface of the flange and the molding material, the convex portion or the concave portion and the molding material are in strong contact with each other, and the gap is sealed here.

[0008]

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In FIG. 1, the reference numeral 10 is a cylindrical coil bobbin made of resin. Flange portions 10a, 10a are integrally formed on the outer periphery of both ends of the coil bobbin 10 in the axial direction so as to be located inside the outermost end. Two ring-shaped protrusions 11 and 12 are formed on the outer surface of the flange portion 10a so as to be concentric with the center line of the coil bobbin 10. The convex portions 11 and 12 are continuous in the circumferential direction, and are spaced apart in the radial direction.

In this embodiment, each of the protrusions 11 and 12 has a rectangular cross section. Therefore, the convex portions 11 and 12 have surfaces P and Q that intersect with the radial direction of the coil bobbin 10, as shown in FIG. A coil 2 made of enamelled wire is wound between the two flanges 10a having the convex portions 11 and 12 formed on the outer surface thereof, and includes the outer periphery of the coil 2 and the outer periphery and outer surface of the flanged portion 10a. The area is integrally covered with a resin molding material 3 such as epoxy resin.

In the coil device having the above configuration, during molding, the ring-shaped convex portions 11 and 12 formed on the outer surface of the flange portion 10a and the molding material 3 are brought into close contact along the shape thereof. At that time, due to the difference in shrinkage rate between the mold material 3 and the material of the bobbin 10, a force F or F' in the radial direction acts on the contact surface, but the protrusions 11 and 12 on the outer surface of the flange 10a Since the molding material 3 and the bobbin 10 have planes P and Q that intersect with each other, the molding material 3 and the bobbin 10 are strongly pressed against each other by the above-mentioned radial force at either plane P or Q. Therefore, even if a small gap is created between the outer surface of the flange 10a and the mold material 3, the protrusions 11, 12 and the mold material 3 will come into close contact with each other, and this strong contact will result in Sealing performance is ensured depending on the part.

Although the convex portions 11 and 12 in the above embodiment have a rectangular cross section, the shape of the cross section is of course not limited to this. FIG. 3 shows examples of various cross-sectional shapes. (a) shows a protrusion 2 having a substantially equilateral triangular cross section on the outer surface of the collar 20a of the bobbin 20.
An example in which 1 is provided is shown below. (b) and (c) are bobbin 30 (
An example is shown in which a convex portion 31 (41) having a right triangular cross section is provided on the outer surface of the collar portion 30a (40a) of 40). (b), (c
) is whether the surface corresponding to the oblique side is placed on the inner circumference side or on the outer circumference side. (d) shows the flange 50 of the bobbin 50.
An example is shown in which a fin-shaped convex portion 51 with a rounded tip is provided on the outer surface of a. All examples have in common that the convex portion has a surface that intersects with the radial direction of the coil bobbin. When a convex portion is formed in this manner, the strength of the bobbin is increased compared to a case where no convex portion is formed. Moreover, from a relative point of view, a concave portion may be formed instead of a convex portion.

0012

[Effects of the Invention] As explained above, since the coil device of the present invention has a concave portion or a convex portion formed on the outer surface of the flange of the coil bobbin, it is possible to more reliably seal between the mold material and the outer surface of the flange. be able to. Note that the recesses or protrusions described above can be easily formed during molding of the bobbin, so they do not particularly increase costs.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional side view of an embodiment of the present invention.

FIG. 2 is a detailed diagram of main parts of the same embodiment.

FIG. 3 is a sectional view of a main part of another embodiment of the present invention.

FIG. 4 is a partially sectional side view of a conventional coil device.

[Explanation of symbols]

2 Coil 3 Resin mold material

Claims (1)

[Claims] Claim 1: Flanges are formed at both ends of a cylindrical coil bobbin, a coil is wound between these two flanges, and a range from the outer periphery of the coil to the outer periphery and outer surface of both flanges is molded with an integral molding material. 1. A coated coil device, characterized in that a ring-shaped concave portion or convex portion continuous in the circumferential direction is formed on the outer surface of the flange portion, which is in close contact with the molding material.