JPS6236269Y2 - - Google Patents

Description

[Detailed explanation of the idea] This invention relates to a coil for a discharge lamp ballast.

As is well known, this type of coil is constructed by winding an electric wire 2 around a winding core 1 in multiple layers with an interlayer paper 3 in between, as shown in FIG. By the way, in this type of coil, pressing forces X and Y are applied in a direction perpendicular to the axis of the winding core.
It has been considered to reduce the coil cross-sectional area by adding During this pressurization, the interlayer paper 3 is sandwiched between the electric wires of the adjacent layers and pressurized, but when this pressing force is strong, the interlayer paper may be torn. When the interlayer paper is torn in this way, the dielectric strength at that location naturally decreases, making it unusable.

The purpose of this invention is to prevent a drop in pressure resistance due to damage to the interlayer paper.

Generally, interlaminar paper is completed by being wound into a roll as shown in FIG. 2 during the manufacturing process. In this case, when examining the tensile strength in the roll direction P and a direction perpendicular to this, it is known that the latter is stronger than the former. For example, for interlayer paper with a paper thickness of 50μ, its tensile strength in the roll direction is
When the tensile strength is 1.5Kg/mm ² , the tensile strength in the direction perpendicular to this is 9.0Kg/mm ² , which is about 6 times the former. Therefore, if the wire is wound in a direction perpendicular to the roll direction P and parallel to the wire 2, it will be less likely to be damaged even if pressure is applied via the wire 2.

To do this, as shown in FIG. 2, the rolled interlayer paper is cut in a direction orthogonal to the roll direction P by a width W as shown by the chain line. This width W corresponds to the width W of the coil 1. The thus cut interlayer paper is used by being wound in a direction perpendicular to the roll direction P as shown in FIG. FIG. 3 is a partially enlarged perspective view, and when the interlayer paper 3 is interposed between the electric wires 2 of each layer, the roll direction P and the longitudinal direction of the electric wires 2 are orthogonal to each other. Pressure force X, Y on the coil
is applied, pressure is applied to the interlayer paper 3 via the electric wire 2, but the pressure at this time is in the roll direction P
interlayer paper 3 in the direction perpendicular to (longitudinal direction of wire 2)
I work to cut it apart. However, since the tensile strength in the direction perpendicular to the roll direction P is sufficiently large, damage to the interlayer paper 3 can thereby be reliably avoided. Therefore, reduction in dielectric strength can also be prevented.

According to the inventor's experiments, the pressurizing force X, Y is 0.8
According to the present invention, the dielectric strength voltage of the interlayer paper was 243 V when pressurized at 100 ton. However, for the same interlayer paper, when the roll direction P and the electric wire were parallel, the voltage was 175V. It is understood that reduction in dielectric strength voltage can be reliably prevented from now on as well.

As detailed above, according to this invention, in a coil whose cross-sectional area is to be reduced by applying pressure from the surroundings, the interlayer paper is wound in a direction perpendicular to the roll direction. It is less likely to be damaged even when pressurized, and this has the effect of reliably preventing a reduction in the dielectric strength of the interlayer paper.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing an embodiment of this invention;
The figure is a perspective view of the rolled interlayer paper, and FIG. 3 is an enlarged perspective view of a part of the coil. 2...Electric wire, 3...Interlayer paper, P...Roll direction.

Claims (1)

[Scope of utility model registration request] In a coil for a discharge lamp ballast formed by winding an electric wire in multiple layers with interlayer paper interposed therebetween and applying pressure from the outer periphery of the wound electric wire, the direction perpendicular to the rolling direction of the interlayer paper is the direction in which the electric wire is wound. A coil for a discharge lamp ballast formed by winding the electric wire interposed between each layer so as to be parallel to the direction.