The core of the transformer is generally made of silicon steel sheets. Silicon steel refers to a silicon content of 08～4.8. The main characteristic of the alloy steel is that it has strong magnetic conductivity, which can produce greater magnetic inductance and reduce the volume of the transformer when the circle is energized.
However, observing the manufacturing process of the transformer, we also found that the core of the transformer is 0The 35mm thick cold-rolled silicon steel sheet is made into a "曰" and "mouth" shaped sheet and superimposed. Why is that?
The reason why a single piece of silicon steel core is not used is to reduce the "eddy current loss" in the core. When the transformer is working, the induced current generated is circulating in a plane perpendicular to the direction of magnetic flux, so it is called eddy current. The superposition of core silicon steel sheets insulated from each other can reduce the passing section of eddy currents, increase the resistance on the path, and suppress the generation of eddy currents. In addition, it can effectively suppress the heating problem of the transformer.
From a principle point of view, the thinner the silicon steel sheet, the better, but in the actual production and manufacturing process, it is necessary to take into account factors such as mechanical strength, difficulty of lamination, and lamination period. Therefore, it is not necessary to use particularly thin lamellae for lamination.
Of course, in addition to the processing technology, the performance of the silicon steel sheet itself is also a key indicator to determine the quality of the finished transformer. When choosing silicon steel sheets, the following indicators should be noted:
1. Low iron loss. The most important indicator of quality, all countries in the world are divided into grades by iron loss value, the lower the iron loss, the higher the grade, and the higher the quality.
2. High magnetic induction intensity. The silicon steel sheet that can obtain higher magnetic inductance under the same magnetic field is smaller in size and weight than the motor or transformer core made of it, which can save silicon steel sheets, copper wires and insulating materials relatively speaking.
3. High stacking coefficient. The surface of the silicon steel sheet is smooth, flat and uniform, and the stacking coefficient of the manufacturing core is improved.
4. Good punching. This is even more important for the manufacture of small and micro motor cores.
5. The adhesion and welding of the surface to the insulating film are good.
6. Magnetic aging.
Silicon steel sheet must be passedAnnealing and picklingLate delivery.