JP2002033213A - Coil and insulating method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dramatically reduce the manufacturing cost of a coil. SOLUTION: A coil conductor 14 insulated with a strand is wound into a coil form and thereafter, and an insulating powder coating 34 is sprayed on the conductor 14 with a spray gun 32 by an electrostatic spray method to form an electrical insulating layer 36 on the outer periphery of a coil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil insulating method and a coil, and more particularly to a coil suitable for use in forming an electric insulating layer on the outer periphery of a coil incorporated in an electromagnet for an accelerator or medical equipment. And a coil having an electric insulating layer formed by the insulating method.

[0002]

2. Description of the Related Art In an electromagnet for an accelerator or a medical device, FIG.
As shown in FIG. 2 (overall view) and FIG. 2 (a cross-sectional view of the coil main body), a coil wire 12 formed by winding a glass tape 16 with epoxy for coil conductor insulation around a coil conductor 14 made of, for example, copper is used. Many coils 10 having a coil body 10A wound in a rectangular shape and a terminal portion 10B are used. In the figure, 14A is the coil conductor 14
Is a cooling passage through which the cooling water passes.

Conventionally, the outer periphery of the coil has been insulated by the following procedure.

(1) As shown in FIG. 2, the irregularities on the outer peripheral side of the coil element wire 12 are filled with an epoxy-based insulating putty 18 and molded, so that the outer peripheral insulating glass tape to be wound next does not float.

(2) A thermosetting thermosetting glass tape 20 for epoxy coating is wound around the entire coil while overlapping.

(3) The insulating putty 18 used in the above process
Then, the outer peripheral insulating tape 20 is cured by heating in a drying furnace (not shown).

(4) A specified color is applied to the coil.

[0008]

However, in such a method for insulating the outer periphery of the coil, the putty filling operation and the tape winding operation take a very long time, and the operation cost is increased. In particular, the coil terminal portion 10B as shown in FIG. 3 (perspective view) and FIG. 4 (cross-sectional view of the coil wire).
Has extremely poor workability. Also, the material cost of the thermosetting tape 20 and the putty 18 is expensive. Further, operations such as heating the coil using a drying furnace are required, and there are many manufacturing steps. Further, since the coil element wire 12 is already insulated by the conductor insulating tape 16, it is necessary to wind the outer peripheral insulating tape 20 thereon to insulate it once again, which is an issue of excessive quality.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems. A first object of the present invention is to make it possible to easily perform insulation work at a low manufacturing cost irrespective of a coil shape or a terminal shape. Make it an issue.

A second object of the present invention is to provide a coil having necessary and sufficient insulation performance at low cost.

[0011]

According to the present invention, when insulating a coil, a coil conductor insulated from a wire is wound into a coil shape, and then a powder insulating paint is sprayed by a spray gun by an electrostatic spraying method. The first problem has been solved by forming an electric insulating layer on the outer periphery of the coil.

Also, the distance between the coil and the spray gun is
The distance is set to be longer than the limit approach distance L (mm) shown by the following equation.

L = −254 * T + 233 (1) where T: conductor insulation thickness of the coil wire (mm)

Further, the second object has been solved by a coil having an electric insulating layer formed by the above method.

In the present invention, the outer peripheral insulation is not performed by using putty or tape as in the prior art, but by the electrostatic spray method.
A powder insulating paint is sprayed on the outer periphery of the coil with a spray gun to form an electric insulating layer.

In general, the electrostatic spraying method is used for applying an epoxy paint to a metal surface. In the present invention, for example, a copper coil conductor is insulated with a glass tape with epoxy, for example. And used to deposit the required coating on the conductor.

At this time, using a spray gun, for example, at -80K
The powder coating is charged by the high voltage of V, and flies toward the grounded coil and fuses. At this time, a voltage is applied to the part where the wire is insulated between the charged paint and the coil conductor, so that the voltage is suppressed so that the wire insulation is not broken, and the coil wire insulation characteristics are adversely affected. A painting method that does not give a paint was found.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings.

In this embodiment, the outer periphery of the coil is insulated by the following procedure.

(1) The coil 10 is heated in a furnace.

(2) In a state where the coil is heated, as shown in FIG.
For example, an epoxy-based powder insulating paint 34 is sprayed around the coil by a spray gun 32 to which a high voltage of, for example, -80 KV is applied by an electrostatic spray method. Then, the powder has an electric charge and is welded to the grounded coil 10,
As shown in FIG. 6 (a cross-sectional view of the coil body), FIG. 7 (a perspective view of the terminal portion), and FIG. 8 (the same cross-sectional view), an electric insulating layer 36 is formed on the outer periphery.

(3) A specified color is applied to the coil as in the conventional case.

If the high-voltage spray gun 32 is too close to the coil 10 during the electrostatic spray coating, a high voltage is generated in the conductor insulation of the coil wire already installed, and the coil wire insulation is broken. There is fear. Therefore,
Considering workability, the limit distance L (mm) at which the coil 10 and the spray gun 32 approach each other, which has no influence on the coil wire insulation, is determined by the conductor insulation thickness T (m) of the coil wire 12.
m) Data was taken from the relationship between (0.13 ≦ T ≦ 0.72) and the generated voltage, and the formula (1) was found.

As an example, the conductor insulation thickness T of the coil wire is T =
FIGS. 9 and 10 show data of the voltage generated in the coil wire insulation portion in the case of 0.13 mm and the case of T = 0.72 mm, respectively.

When T = 0.13 mm, the approach limit distance L to the coil is 200 mm from equation (1). From FIG. 9, it can be seen that when approaching from 200 mm to 50 mm, a considerably high voltage (around -500 V) is generated.

On the other hand, when T = 0.72 mm, the approach limit distance to the coil is 50 mm from the equation (1).
From this, it can be seen that even when approaching to 50 mm, the generated voltage is about −40 V, and there is no problem in insulation.

In the above embodiment, an epoxy powder insulating paint is electrostatically spray-coated on the outer periphery of the coil in which the copper coil conductor is insulated by a glass tape with epoxy, so that the epoxy on the outer periphery of the coil is removed. The electric insulation layer was formed, but the coil element wire insulation was performed with a tape other than glass tape with epoxy, or the electric insulation layer around the coil was formed with a powder insulation paint other than epoxy-based powder insulation paint It is also possible.
The material of the coil conductor is not limited to copper.

In the above embodiment, the present invention provides:
Although it was applied to a rectangular D-shaped coil, the shape of the coil is not limited to this, but may be a linear type, a curved type, or a quadrupole (Q).
It can be applied to coils of any shape, such as for electromagnets.
In particular, the more complicated the shape, the higher the effect of the invention.

The use of the coil is not limited to those incorporated in an accelerator or an electromagnet for medical equipment.

[0030]

According to the present invention, the manufacturing cost including the material cost can be drastically reduced as compared with the prior art. In particular, the insulation of the terminal can be performed in a very short time. Become. Further, a minimum necessary electric insulating layer can be formed, and waste can be eliminated. Further, insulation can be easily performed regardless of the size of the coil shape or the terminal shape.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the shape of an example of a coil.

FIG. 2 is a cross-sectional view showing a detailed shape of a cross section of a coil body in which conventional coil insulation is performed.

FIG. 3 is a perspective view showing a terminal part of the same.

FIG. 4 is a cross-sectional view of the terminal part.

FIG. 5 is a perspective view showing a state in which electrostatic spray coating is performed according to the embodiment of the present invention.

FIG. 6 is a cross-sectional view of the coil main body, showing an insulating structure of the coil formed according to the embodiment.

FIG. 7 is a perspective view showing a terminal portion of the same.

FIG. 8 is a cross-sectional view of the terminal part.

FIG. 9 is a graph for explaining the principle of the present invention, in which the generated voltage is measured when the distance between the spray gun and the coil is reduced from 200 mm to 50 mm when the conductor insulation thickness T of the coil wire is 0.13 mm. Time chart showing examples

FIG. 10 is a time chart showing a measurement example of a generated voltage when T = 0.72 mm;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Coil 10A ... Coil main body 10B ... Coil terminal part 12 ... Coil strand 14 ... Coil conductor 16 ... Conductor insulating tape 32 ... Spray gun 34 ... Epoxy powder insulating paint 36 ... Electrical insulating layer

Claims (3)

[Claims] The present invention is characterized in that, after winding a coil conductor insulated by a wire into a coil shape, a powder insulating paint is sprayed with a spray gun by an electrostatic spraying method to form an electric insulating layer around the coil. Coil insulation method. 2. The coil insulating method according to claim 1, wherein the distance between the coil and the spray gun is greater than a limit approach distance L (mm) represented by the following equation. L = −254 * T + 233, where T: conductor insulation thickness of the coil wire (mm) 3. A coil having an electrically insulating layer formed by the method according to claim 1.