Coil bobbin

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a coil bobbin, and more particularly to a coil bobbin for a small electric motor in which a winding machine is used to wind a winding on an outer cylindrical surface of a cylindrical body having flanges on both sides.

【0002】

[Conventional technology]

FIG. 5 is a front view (a) and a side sectional view (b) showing the structure of a conventional general coil bobbin. As shown, the bobbin 1 has flange-shaped flanges on both ends of a hollow cylinder. The bobbin 1 has a shape that is provided on the entire circumference, and windings are wound multiple times on the outer cylindrical surface 1b of the bobbin 1 to form a winding portion 4. FIG. 6 is a diagram showing a state in which the winding is correctly wound around the bobbin 1. As shown in FIG. 3A, when the winding start leader wire 3 is wound so as to be in close contact with the inner surface 1a of the flange of the bobbin 1, as shown in FIG. The winding portion 4 can be formed by regularly aligning on the outer cylindrical surface 1b between them.

【0003】

[Problems to be Solved by the Invention]

In the prior art, as shown in FIG. 7 (a), the winding is introduced with respect to the bobbin 1 at an angle θ, and the coil is wound on the outer cylindrical surface 1b while being pulled from a position slightly distant from the flange inner surface 1a of the bobbin 1. When the winding is started, as shown in FIG. 7 (b), the winding start leader wire 3 does not come into close contact with the inner surface 1a of the flange of the bobbin 1, and thereafter, the winding is continuously wound and the winding starts. The density of the winding portion 4 is locally increased by crossing the leader wire 3, and as a result, the insulating coating is damaged by the frictional force between the windings generated by the winding, resulting in a poor short circuit or excessive tension. There was a problem that disconnection failure occurred due to stress. However, since the ratio of the outer diameter of the flange of the bobbin 1 to the diameter of the outer cylindrical surface is not constant, it is not easy to start winding in close contact with the inner surface 1a of the flange. The present invention aims to improve the shape of the coil bobbin 1 that winds the winding regularly by a simple structure, and provides a coil bobbin suitable for winding the winding start leader wire 3 along the inner surface 1a of the flange. It is an object.

【0004】

[Means for solving problems]

In order to achieve the above object, the present invention is formed on the outer cylindrical surface of a cylinder having flanges on both sides by a predetermined downward slope from a predetermined position on the outer cylindrical surface toward one inner surface of the flange. A coil bobbin having a gradient groove on the entire circumference, and this gradient groove starts at a position of 10% to 50% of the width of the entire outer cylindrical surface from the inner surface of the flange and goes from the inner surface of the flange to the inner surface of the flange. It is formed by 60 °. Nylon and PBT (polybutylene terephthalate) resin materials are generally used as the material of the coil bobbin, and polyester and polyurethane coated copper wire are used as the wire material for winding the coil bobbin of the small electric motor. ..

【0005】

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will be described with reference to the drawings. <Embodiment 1> FIGS. 1 (a) and 1 (b) are diagrams showing the first embodiment of the coil bobbin of the present invention. That is, unlike the conventional bobbin 1, the bobbin 11 of the present invention has a gradient groove 12 formed between the flange inner surface 11a and the outer cylindrical surface 11b. 2 (a) and 2 (b) are views showing a state in which a winding is wound around the bobbin 11 of the present invention to form a winding portion 14. When the winding of the winding is started with respect to the bobbin 11, as shown in FIG. 2 (a), the winding start leader wire 3 is guided along the gradient groove 12 and as a result, is brought into close contact with the flange inner surface 11a. After that, as shown in FIG. 2 (b), the windings are sequentially laminated and wound to form the winding portion 14, so that the winding portions 14 are formed. Like the conventional bobbin 1 shown, the partial density of the winding part 4 near the lead-out wire 3 at the start of winding is higher than that of other parts, and therefore, due to the frictional force between the windings generated by winding, It is possible to prevent adverse effects such as damage to the insulating film causing insulation failure and disconnection failure due to excessive tensile stress.

【0006】

As shown in FIG. 4A, the gradient groove 12 has a position of W / D0.2 to 0.3 and a flange from the outer cylindrical surface, where D is the width of the outer cylindrical surface 11b and W is the width of the gradient groove 12. When the angle of the downward gradient toward the inner surface of the bobbin is β, it is generally preferable to have a gradient of β 10 ° to 30 °, but the outer diameter of the flange of the bobbin 11 and the diameter of the outer cylindrical surface It is necessary to make adjustment selection within the range described in the claim depending on the ratio, the structure of the winding machine, the wire diameter of the winding, the winding tension, the material of the bobbin, and the like. The gradient groove of the present invention also includes a curved (convex or concave) gradient groove 12'as shown in FIG. 4 (b).

【0007】

<Embodiment 2> FIG. 3 is a diagram showing the second embodiment of the coil bobbin of the present invention. Since the object of the present invention is to wind the winding around the bobbin by reducing the number of intersections with the winding start leader wire 3 as much as possible, the gradient groove 12 of the present embodiment is as shown in the drawing. In addition, instead of forming the entire circumference of the outer cylindrical surface 11b, the winding start leader wire 3 partially forms a gradient groove 12 on an arc in the range of 90 ° to 120 ° after the start of contact with the outer cylindrical surface 11b. By setting, it is possible to reduce the thin portion of the bobbin 11 and improve the flow of hot water during molding. In this embodiment as well, as in the first embodiment, the position of the winding starting to be wound and following the leader wire 3 can be regulated so as to be along the inner surface 11a of the flange.

【0008】

[Effect of the invention]

The winding wound around the coil bobbin of the present invention intersects with the lead wire at the beginning of winding, and the winding density of the winding portion is locally increased. Therefore, the frictional force between the windings generated by the winding As a result, it is possible to prevent adverse effects such as damage to the insulating film, poor insulation, poor rare short circuit, and poor disconnection due to excessive tensile stress.

[Simple explanation of drawings]

[Figure 1]

It is a figure (a), (b) which shows Embodiment 1 of the coil bobbin of this invention.

[Figure 2]

It is a figure (a), (b) which shows the state which forms the winding part by Embodiment 1 of the coil bobbin of this invention.

[Fig. 3]

It is a figure which shows Embodiment 2 of the coil bobbin of this invention.

[Fig. 4]

It is a figure (a), (b) which shows the gradient groove of the coil bobbin of this invention.

[Fig. 5]

It is a figure (a), (b) which shows the conventional coil bobbin.

[Fig. 6]

It is a state (a), (b) which shows the state which a normal winding part is formed in the conventional coil bobbin.

[Fig. 7]

It is a state (a), (b) which shows the state which an illegal winding part is formed in the conventional coil bobbin.

[Explanation of symbols]

1, 11 ... Bobbin 1a, 11a ... Flange inner surface 1b, 11b ... outer cylindrical surface 3 ... Winding start leader wire 4, 14 ... Winding part 5 ... End of volume Leader 12 ... Gradient groove 12'... Curved gradient groove