JPS6031180B2 - Manufacturing method of iron core for duct - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a duct core for cooling ventilation used in a stator core of a rotating electrical machine.

In recent years, as the single unit capacity of generators has increased, the iron cores used have also become larger, requiring high quality and low cost. In particular, in the core lamination work of the stator core, it is necessary to provide iron with well-aligned laminated surfaces, no waving, and well-tightened steel at a low cost. Figure 1 generally shows a stator core for a generator; 1 is the stator frame, 2 is fixed to the inner side of the frame,
4 is a laminated core formed by stacking iron plates along the dovetail of the rib stud 2; 4 is a duct core installed between the cores of the laminated core 3 to form a cooling ventilation duct; 5 is a duct core of the laminated core 3; The outer spacing piece attached to the outside, 6 is the laminated iron core 3
This is a holding plate that is vertically attached with nuts, sandwiching the duct iron core 4 and the outer spacing piece 5. FIGS. 2 and 3 show a conventional duct iron core 4, in which 7 is a duct iron plate, 8 is a spacing piece arranged at intervals on one side of the duct iron plate 7,
Reference numeral 9 denotes the spot welding in which the spacer piece 8 is fixed to the steel plate 7 for the duct, and an insulating film covered with debris to prevent rust.

The insulating film 10' was formed by spot welding and fixing the spacing piece 8 to the duct iron plate 7, and then dipping it in Class A insulating varnish and drying it naturally. This insulating film 10 is formed so that the spacing pieces 8 are made of iron and will not rust and cause problems, and even if the duct iron plate 7 is coated with varnish in advance like the core of the laminated core 3. Since it will be painted after spot welding, varnishing is not applied to eliminate two types of painting. However, since the insulating film 10 is formed by dipping coating, the varnish adheres to the surface of the duct iron plate 7 and the spacing piece 8 in the duct iron core 4 after drying, and the varnish is thickly coated, and the duct core 4 is coated thickly. The varnish was applied in puddles, and the thickness of the coating film varied by about 0.2 degrees and was not uniform.

For this reason, in the lamination work of the stator core, the surface of the duct core 4 is not slippery and requires a lot of time and effort, the core lamination surface is not evenly aligned, and the varnish coating thickness is uneven. In addition, since it is two-sided, the laminated core cannot be tightened sufficiently, which adversely affects the unwavy core of the laminated core 3, causing waving, and the long-term operation of the generator due to changes in the mass of the varnish over time. This had the drawback that the iron core inside the generator could become loose, impairing the performance of the generator. The present invention has been made in view of the above-mentioned drawbacks, and eliminates the partial puddle-like coating of the insulating film caused by the conventional varnish coating for rust prevention, and makes the coating thinner to prevent stator cores. To provide a method for manufacturing a rear core for a duct which can strengthen the core and prevent loosening due to aging of the core. An embodiment of the present invention shown in the drawings will be described below.
In FIGS. 4 and 5, parts having the same functions as those in FIGS. 2 and 3 are designated by the same reference numerals, and their explanations will be omitted.
Before spot welding the spacing pieces 8 to the duct iron plate 7, as a first step, apply a resin that can be applied at high temperatures, such as phenolic class B varnish, to the duct iron plate 7 only to a thickness of about 5 microns using a varnish roller. After coating, the insulating film 10 is formed by forced baking in an atmosphere of about 60,000 yen. Therefore, the surface of this insulating film is smooth and the coating thickness is uniform, with no variation in thickness. Next, as a second step, stainless steel spacing pieces 8 are arranged on one side of the duct iron plate 7 and fixed by spot welding. Next, the effect will be explained.

According to the test results, the strength of spot welding between the duct iron plate 7 and the spacing piece 8 in the duct iron core 4 manufactured in this way is as follows: It was almost the same. Therefore, the duct iron D4 is the insulating film 1 on only one side of the duct iron plate 7.
Since the thickness of the stator core 0 is thin and uniform and the surface is smooth, and the spacer piece 8 is made of stainless steel, the stator core is flat without undulations, and the insulating film 10 of the duct core 4 has no adverse effect on other laminated cores. , it is possible to provide an iron core that is firmly tightened without loosening. As described above, according to the present invention, only the duct iron plate is coated with a resin that can be applied at high temperatures in a loaf manner, and after the duct iron plate is forcibly phosphorized at 600 pm, an insulating film is attached to the stainless steel spacing piece. Since the duct iron core is spot welded and fixed to the duct iron plate without being exposed, the thickness of the insulating film of the duct iron core is thin and uniform, and only on one side, and the surface is smooth and the stator The laminated core can have a high space factor, and the core is firmly tightened without waving, so the generator will not loosen the core during long-term operation.

In addition, the core lamination work has excellent effects such as being able to reduce labor and time.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view showing a general stator iron D for generators, Figure 2 is a front view showing a conventional duct iron core, and Figure 3 is a
FIG. 4 is a front view showing one embodiment of the duct iron D of the present invention, and FIG.
FIG. 3 is a vertical cross-sectional view taken along line B. 4... Iron D for ducts, 7... Iron plate for ducts, 8... Spacing piece, 9... Spot welding, 10... Insulating film . Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. The first step is to apply a high-temperature baking resin such as phenolic varnish only to the iron plate for the duct and forcibly bake it at 600°C.The spacer piece is made of stainless steel and the duct is left bare without an insulating film. A method for manufacturing an iron core for ducts, which comprises a second step of spot welding to a steel plate.