JPS6322450B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an electric machine winding made of aluminum round wire coated with formal insulation.

Resin-insulated aluminum round wire coated with synthetic resin (for example, formal aluminum round wire, polyester imide aluminum round wire) is used as a conductor for windings of electric motors and transformers. However, the diameters of these round wires are only graded; for example, when designing a certain transformer, the diameter of 2.8
Even if you need a mm round wire (cross-sectional area 6.15 mm ² ), there are cases where only 2.9 mm round wire (cross-sectional area 6.61 mm ² ) is available (supplied). At this time, the amount of line used is approximately 7.5
% will also be higher than necessary.

In addition, if you try to prepare a special round wire with a diameter of 2.8 ^mm2 , the manufacturing cost will be extremely high when the production quantity is small, and the electric motors and transformers manufactured using this wire will also be expensive. Become.

On the other hand, resin-insulated aluminum round wires have few pinholes and the thickness of the insulation coating is fairly uniform, but their dielectric breakdown characteristics vary to some extent. For this reason, in electrical equipment whose insulation is designed to have the lowest dielectric breakdown voltage, if there are large variations in dielectric breakdown characteristics,
Even if the average value is high, there is a risk of dielectric breakdown.

In particular, the present invention uses a round aluminum wire coated with formal insulation and is wound while elongating the wire by 2 to 10% in the length direction.

SUMMARY OF THE INVENTION In order to solve the above-mentioned drawbacks, the present invention aims to provide a method of manufacturing an electrical winding wire that can easily obtain a round aluminum wire coated with formal insulation of a desired diameter and that can reduce variations in dielectric breakdown characteristics. .

Hereinafter, one embodiment of the present invention will be described in detail using the drawings. FIG. 1 shows a state in which a formal insulation coated aluminum round wire 3, which is a round aluminum wire conductor coated with a formal insulation coating, is wound around an insulating tube 2. Note that 1 indicates a winding pattern. When winding the formal insulation coated aluminum round wire 3 around the winding die 1, the aluminum round wire 3 is rotated in the direction of the arrow (longitudinal direction of the aluminum round wire 3).
A tensile force F is applied to the round aluminum wire 3 to elongate it by 2 to 10%. When winding aluminum round wire around a winding die, tensile force is generally applied to prevent the winding from loosening. However, if this tensile force is too large, the number of revolutions of the winding machine will drop, so it is normal that the tensile force is not too large.

In the embodiment of the present invention, the aluminum round wire 3 is wound into a winding die 1.
For example, when winding ^the
In the above manner, the aluminum round wire 3 is wound while being stretched by 2 to 10% while maintaining the rotational speed of the winding machine at a certain predetermined rotational speed to form a winding wire.

Figure 2 shows the experimental results regarding the elongation and dielectric breakdown voltage of a round aluminum wire coated with formal insulation. As the elongation of the aluminum round wire increases, the average value of the dielectric breakdown voltage gradually increases and then rapidly decreases.
On the other hand, the dispersion also decreased rapidly with growth, and then suddenly increased. In other words, the average value of dielectric breakdown voltage gradually increases with elongation,
When the growth is about 11%, it is again the same as when the growth is 0%. On the other hand, the variation in breakdown voltage becomes smaller when the elongation is about 2%, and about
It shows a tendency to increase when it exceeds 10%. From this, it is clear that formal insulation coated aluminum round wire is
If used with ~10% elongation, the average value of dielectric breakdown voltage will be the same as or higher than that of 0% elongation, and on the other hand, the variation in dielectric breakdown voltage will be small, with the lowest value at elongation of 2% compared to 0% elongation. %, about 11% higher, growth
10% is about 7% higher. Therefore, as in the above example, 2 to 10% of formal insulation coated aluminum round wire is used.
By stretching and winding, a winding wire with excellent dielectric strength can be obtained.

In the figure, the "O" mark indicates the average value, and the "I" mark indicates the range of data variation.

Now, FIG. 3 illustrates the relationship between the elongation of a round aluminum wire coated with a formal insulation coating, the wire diameter (including the insulation coating), and the conductor diameter. In the figure, "○" indicates the wire diameter, "I" indicates its variation, and "△" indicates the conductor diameter. In FIG. 3, the conductor diameter decreases approximately in proportion to the elongation. More precisely, if the wire diameter at 0% elongation is γ ₁ and the wire diameter at α% elongation is γ ₂ , γ ₂ is determined by the following formula.

On the other hand, if the insulation coating behaves in the same way as a conductor when the aluminum round wire is stretched, the insulation coating thickness t can be obtained from the following relationship.

However, t ₀ = γ ₁ − γ ₀ (γ ₀ is the conductor diameter when the elongation is 0%) The conductor diameter is almost the same as the calculated value obtained by equation (1) and the actual value, so it is difficult to use aluminum round wire. It was found that even when stretched, the wire diameter increases uniformly in the length direction.
In addition, although the average value of the insulation coating thickness calculated using equation (2) and the measured value were almost the same, there was some variation, and the variation was small up to 10% elongation, and no variation when the elongation exceeded 10%. It got bigger. This variation in the thickness of the insulating film almost corresponds to the value of the dielectric breakdown voltage and its variation in FIG. 2, and it can be seen that if the elongation exceeds 10%, it is unacceptable from this point of view as well. In addition, when the elongation is less than 10%, the aluminum round wire stretches almost uniformly in the length direction with respect to the elongation, and the wire diameter is also almost uniform. There will be no manufacturing errors even when used.

In this way, due to the dielectric breakdown voltage, the relationship between conductor diameter and elongation, and the relationship between insulation coating thickness and elongation, even if formal insulation coated aluminum round wire is used after being stretched by 2 to 10%, insulation will deteriorate and manufacturing errors will occur. Rather, the dielectric breakdown voltage becomes higher, and a winding wire with an optimum wire diameter can be obtained.

As explained above, according to the method of the present invention, it is possible to set the wire diameter of formal insulation coated aluminum round wire to a desired value, reduce the amount of aluminum round wire required for winding, and reduce dielectric breakdown. It is possible to obtain a highly reliable electric machine winding with small voltage variations.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing the winding state of electrical windings, Figure 2 is a graph showing the relationship between elongation and dielectric breakdown voltage of aluminum round wire coated with formal insulation, and Figure 3 is a graph showing the relationship between elongation and round aluminum wire coated with formal insulation. 2 is a graph illustrating the relationship between the wire diameter and the conductor diameter. 1... Winding type, 2... Insulating tube, 3... Formal insulation coated aluminum round wire.

Claims (1)

[Claims] 1. A method for manufacturing an electrical winding wire, which comprises winding a formal insulation coated aluminum round wire while elongating it by 2 to 10% in the length direction.