JPH0279405A - Manufacture of synchrotron iron core - Google Patents

Abstract

PURPOSE:To make it possible to simply remove minute chips and burrs which cause partial short-circuit between steel plates by applying permeable resin to the surface of iron core where steel plates are opposed with space between and hardening it, and then cutting the surface of this iron core so as to smooth it, and applying strong acid, and then washing it so as to remove the strong acid. CONSTITUTION:Resin 13 is applied to the surface of iron core 1 which is formed by stacking silicon steel plates 11, and is hardened. And by applying cutting processing, irregularity at every applied resin 13 and silicon steel plate 11 disappears from the surface 15 of the iron core, and the surface 15 of the iron core is becoming high smoothness. When nitric acid is applied to the surface 15 of the iron core after cutting process, minute chips and burrs are melted in the nitric acid and are removed. For this reason, the places which are short- circuited by cutting process between adjacent silicon steel plates 11 are dissolved and it becomes an iron core without short-circuited places. Since resin 13 is charged into the space between silicon steel plates 11, it prevents the nitric acid from permeating into this space, and silicon steel plates 11 at the parts other than the surface 15 of the iron core never begins to melt.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) This invention relates to a method for manufacturing a synchrotron core for accelerating charged particles to create high-energy particles.

[Conventional technology]

A synchrotron is a device in which electromagnets are arranged in a circle to rotate and accelerate particles, and has been used in research on high-energy particles as a particle accelerator particularly suitable for obtaining high-energy particles. In recent years, progress has been made in various fields to utilize high-energy electromagnetic waves generated by synchrotron radiation of high-energy particles generated by synchrotrons.

Although a synchrotron for such practical use may be relatively small-scale, it is required to be low-priced.

One of the performance requirements for synchrotrons used in various fields is that they must be able to continuously obtain high-energy particles. There are two types of synchrotrons: a synchrotron called an accelerating ring for obtaining high-energy particles, and a synchrotron called a storage ring for storing high-energy particles generated in this accelerating ring and taking them out and using them as needed.
A device consisting of two synchrotrons will be adopted.

In the storage ring, since it is sufficient to keep the energy value of the charged particles constant, the magnetic flux density generated by the iron core forming the storage ring is constant. Since the acceleration ring periodically generates high-energy particles and supplies them to the storage ring, the magnetic flux density generated by the iron core that makes up the acceleration ring changes periodically in proportion to the period of high-energy generation. is necessary.

This periodically changing magnetic flux density waveform is a trapezoidal waveform consisting of three parts: a linearly rising wave front, a flat part where the value is constant after that, and a damping part after that. It is a periodic waveform with a frequency of about 3 centimeters. Charged particles are accelerated at the wave front to generate high-energy particles, and the high-energy particles generated at the flat portion are injected into the storage ring.

By periodically repeating such operations, high-energy particles for continuous use are generated and replenished.

Figure 3 is a cross-sectional view of the synchrotron core as an accelerating ring. A C-shaped core 1 is provided with a cavity 3, and a magnetic field is generated within this cavity 3 and is passed perpendicularly to the plane of the paper. Protons and electrons are charged particles that run in the direction of . Coils 21 and 22 are wound around the core on both sides of the gap 3, and magnetic flux is generated in the core 1 by passing excitation current through these coils 21 and 22. The actual shape of the iron core 1 is fan-shaped with the center axis on the left side of the figure, and by arranging a plurality of iron cores 1 in a circular shape, a running path is formed in which charged particles can circulate.

As mentioned above, in order to generate periodically changing magnetic flux, the iron core 1 is used in transformers and rotating machines in order to suppress the eddy current generated within the iron core to the extent that it does not affect changes in magnetic flux. A silicon steel plate with an inorganic insulating film formed on its surface is punched out into a predetermined shape and laminated to a predetermined thickness. As mentioned above, since the iron core l is fan-shaped, it is necessary to make the lamination thickness larger on the outer diameter side on the right side than on the inner diameter side on the left side of the figure, so the silicon steel plate is thicker on the outer diameter side. The structure is such that the number of layers stacked is large.

The size of the iron core 1 varies depending on the application, but for example, in this figure, the inner diameter dimension Φ of the iron core is 600v++, and the cavity 3 of the iron core is
The gap length is 50 au+, the width of gap 3 is 200 mm,
The accuracy of the gap length of the gap 3 is required to be ±25μ. Accordingly, the iron core surface sandwiching the gap 3 is also required to have a high level of smoothness. If the accuracy of the air gap length or the smoothness of the core surface is poor, the value and distribution of the magnetic flux density in the air gap 3 will not be as designed, which will reduce the efficiency of high-energy particle generation and make it difficult to generate a constant amount of high-energy particles. The equipment becomes large and expensive.

As mentioned above, in order to put the synchrotron into practical use, the synchrotron must be inexpensive, so it is necessary to manufacture the cavity 3 with high precision and high smoothness as described above.

In the iron core formed by laminating silicon steel plates, the above-mentioned 1
In order to obtain dimensional accuracy and smoothness of 0 μ-level, it is impossible to achieve it simply by laminating layers, and it is necessary to cut the surface of the iron core.

(Problems to be Solved by the Invention) When silicon steel plates are laminated and their surfaces are cut, a phenomenon occurs in which minute cutting debris crosses the insulation coating and causes a short circuit between adjacent silicon steel plates. In addition, minute protrusions called "burrs" that occur at the ends of silicon steel plates due to cutting work also cause short circuits between the silicon steel plates.

Such local short circuits naturally occur in many places, but as a result, large return current paths are created, and eddy currents flow through this return circuit due to the electric M1 induction effect due to changes in magnetic flux, resulting in temporal changes in magnetic flux density. This causes the waveform of the synchrotron to be distorted, and the problem arises that even though the synchrotron was intended to be manufactured with high efficiency, it actually becomes a synchrotron with low efficiency due to the eddy current. Because of these problems caused by cutting the core surface, in the case of iron cores where the value of magnetic flux density that changes over time is an important factor,
This was a major reason why cutting could not be used to improve accuracy.

This invention makes it possible to easily remove minute cutting debris and protrusions that cause local short circuits between steel plates that occur when cutting the core surface of a void that requires dimensional accuracy and smoothness. The purpose of this study is to provide a method for manufacturing iron cores that can be used.

[Means to solve the problem]

In order to solve the above problems, the present invention provides an iron core having a C-shaped cross section with a certain gap, which is formed into a predetermined shape by laminating magnetic steel plates whose surfaces are coated with an insulating film. In the synchrotron core, a permeable resin is applied to the core surfaces facing each other across the gap and cured, the core surface is cut to make it smooth, then strong acid is applied, and then washed with water. Strong acids shall be removed.

[Function] In the configuration of the present invention, a permeable resin is applied to the surfaces of the core facing each other with a gap in between, and is cured to fill the minute gap that occurs between adjacent magnetic wire plates. When machining, metal contact between adjacent magnetic steel plates occurs due to cutting chips and local protrusions on the surface of the steel plates.After this, when strong acid is applied to the surface of the core, the cutting wastes and protrusions mentioned above are removed. It dissolves in strong acid and is removed, but because it is filled with resin, the strong acid does not penetrate into the gaps between the magnetic steel plates, and the strong acid remains coated only on the surface of the iron core. After this, the strong acid is removed by washing with water, but it can be easily washed away and no strong acid remains behind.

〔Example〕

The present invention will be explained below based on examples. 1 and 2 are enlarged cross-sectional views of a part of the surface portion of the iron core 1 sandwiching the gap 3 in FIG. 3 as a schematic diagram for explaining the invention in detail, and FIG. The state after coating the resin 13 on the surface of the iron core I formed by laminating silicon steel plates 11 and hardening it is shown in FIG. 2, where the surface of the iron core shown in FIG. The state after the surface 15 is formed is shown.

The resin 13 is a two-component adhesive that is a mixture of an epoxy resin and a curing agent and hardens at room temperature, and is commercially available under the trade name Araldite. There are various types of adhesives of this type depending on the application, but the essential requirement for the resin 13 is that it has a low viscosity so that it can penetrate into the gaps between the silicone steel plates 11.
A method is used to lower the viscosity by mixing a small amount of diluent.

In these figures, the gaps between adjacent steel plates 11 are shown as constant intervals, but in reality, the steel plates are tightened together with a predetermined pressure to create a structure with as little gap as possible. The uniform and large gaps shown do not actually occur; silicon steel plates with excellent alternating magnetic properties are used as the steel plates, but the thickness is 0.35 mm, and there are no gaps formed on the surface. The insulation film has a thickness of about 10μ.

Since FIG. 1 shows the surface of the iron core 1 before cutting, the resin 13 has permeated into the gap 12 between the steel plates and has been applied to the surface of the iron core 1.

In addition, the core surface of each silicon steel plate 11 is uneven and not smooth, and the degree of unevenness is determined by the accuracy of positioning when stacking the silicon steel plates, but it is 100 μm.
It is difficult to do the following:

Figure 2 shows the state after cutting, and the surface 15 of the core has no irregularities caused by the resin 13 and silicon steel plate 11 that were applied, and the surface 15 of the core has a high degree of smoothness. . When nitric acid is applied to the core surface 15 after cutting, minute cutting chips and protrusions not shown in this figure are dissolved in the nitric acid and removed. Therefore, the adjacent silicon steel plate 1
1, the short-circuited parts due to the cutting process are eliminated, resulting in an iron core 1 with no short-circuited parts. The gaps between the silicon steel plates 11 are filled with resin 13 to prevent nitric acid from penetrating into the gaps, and the silicon steel plates in areas other than the core surface 15 will not melt.

After this, the iron core surface 11 is washed with water to wash away the nitric acid, but even in this process, the nitric acid penetrates into narrow gaps and is only attached to the chair surface, so it can be easily washed away. This is an effect due to filling.

Since the core surface 15 is the core surface on both sides of the gap 3 in Fig. 3, it is necessary to insert a cutting blade into the gap 3 in order to cut this core surface. By a milling machine using a milling blade.

[Effects of the Invention] As described above, this invention applies a permeable resin to the surfaces of the core facing each other with a gap in between, and allows the resin to penetrate into the gap between the magnetic steel plates and harden. If the gap is filled with resin and then the surface of the core is machined, there will be areas where the adjacent steel plates are locally short-circuited due to cutting debris or local protrusions on the surface of the steel plates. When applied, the aforementioned cutting chips and protrusions are dissolved in the strong acid and removed, but since the resin is filled between the adjacent steel plates, the strong acid does not penetrate into the gaps between the steel plates.After this, it is washed with water. However, by filling with resin, the strong acid can be easily washed away.

In this way, by simply applying resin or strong acid, it is possible to remove local short circuits between the magnetic steel plates that occur during cutting, which improves the smoothness of the core surface in the gap and improves the smoothness of the core surface. It is a synchrotron that can efficiently generate high-energy particles because cutting can be used to increase the accuracy of the gap length.
As a synchrotron for obtaining a predetermined amount of high-energy particles, the synchrotron is small and inexpensive.

[Brief explanation of the drawing]

1 and 2 are sectional views for explaining the invention in detail, and FIG. 3 is a sectional view of the synchrotron core.

Claims (1)

[Claims] 1) An iron core with a C-shaped cross section with a constant air gap,
In a synchrotron core formed by laminating magnetic steel plates whose surfaces are coated with an insulating film and formed into a predetermined shape, a permeable resin is applied to the core surfaces facing each other across the gap and cured, and then A method for manufacturing a synchrotron core, which is characterized by cutting the core surface to make it smooth, then applying strong acid, and then washing with water to remove the strong acid.