JPH0136967B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a coil for a discharge lamp ballast.

In this type of coil, electric wire is wound around the winding core in multiple layers with interlayer paper interposed between them, and is pressurized in a direction perpendicular to the axis of the winding core to shorten the distance between the layers and reduce the cross-sectional area. The present inventor has separately proposed a manufacturing method in which the coil length is shortened by applying pressure also in a direction parallel to the axis to shorten the distance between adjacent turns in each layer.

To explain this more specifically, the coil 1 shown in FIG. 1 is constructed by winding an electric wire 3 around a winding core 2 with an interlayer paper 4 interposed, and the coil 1 is wound in a direction perpendicular to the axis of the coil 1. Pressure forces X and Y are applied to reduce the cross-sectional area, and pressure force Z is applied in a direction parallel to the axis.
is added to shorten the coil length. For example, as shown in FIG. 2, these pressures may be applied by fitting the coil 1 onto the core leg 5 on which the coil 1 is to be wound, and applying pressure from each direction. When applying the pressing force Z, one end of the coil may be pressed against the core leg 6 that intersects with the core leg 5, and the pressure may be applied by pressing the pressing tool 7 against the other end.

By the way, in general, the external insulating paper (insulating paper wound as the outermost layer) of this type of coil 1 is stipulated to have a thickness of 0.3 mm or more in terms of standards. Conventionally, therefore, it has been customary to make double-wraps of insulating paper with a thickness of 0.18 mm. However, with insulating paper of this thickness, it is difficult to bend because it is thick.
When the pressing force Z is applied as described above, the edge of the insulating paper (normally, this edge is located further outside than the outermost wire) does not bend, for example, in a zigzag shape. It may become bent. If this bends to the surface of the wire, it will disturb the winding state of the wire, which has been carefully wound in an aligned manner. This cannot satisfy the intention of shortening the cross-sectional area and length of the coil.

The object of this invention is to prevent the alignment of electric wires from being disturbed even by the presence of external insulating paper.

This invention is characterized in that interlayer paper 4 is used as the external insulating paper. That is, the interlayer paper 4 is generally thin, with a thickness of about 0.05 mm or 0.08 mm, and is therefore much weaker than conventionally used external insulating paper. Therefore, according to the present invention, a plurality of such sheets are used to obtain the thickness required by the standard. For example, thickness
7 sheets of 0.05mm interlayer paper or 4 sheets of 0.08mm thick interlayer paper
You can use one. 8 indicates an external insulating paper consisting of a plurality of sheets of interlayer paper. In this case, a plurality of sheets of interlayer paper may be stacked and wound or may be wound in a plurality of layers.

When a coil having external insulating paper having such a configuration is pressurized with the pressing force Z as described above, each interlayer paper 4 will be exposed to the core legs 6 at the edge ends thereof, as shown in FIG.
(or the pressing tool 7) (this is the same as in the conventional case), and the outer insulating paper 8 also bends from the waist at its edge. Therefore, it is possible to reliably prevent the conventional thick external insulating paper from bending in a staggered manner.

As detailed above, according to the present invention, when compressing the coil to shorten the coil, the outer insulating paper is composed of a plurality of sheets of interlayer paper, so that there is no possibility that the folding pattern will be disordered when the coil is pressurized. Since the wires are bent from the waist portions at the ear ends without causing any disturbance in the alignment of the wires, this effect is achieved.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the coil in the pressurizing direction, FIG. 2 is a plan sectional view showing the pressurizing situation, and FIG. 3 is a partially enlarged sectional view. 1... Coil, 3... Electric wire, 4... Interlayer paper, 8
...External insulation paper.

Claims (1)

[Claims] 1. A coil is constructed by winding an electric wire in multiple layers with interlayer paper interposed therebetween, and using a plurality of sheets of interlayer paper on the outermost layer of the wire so as to have a thickness required as an external insulating paper. A method for manufacturing a coil for a discharge lamp ballast, wherein the interlayer paper and the edge portions of the outermost interlayer paper are bent from the waist by applying pressure along the axial direction of the coil.