JPS6053003A - Superconductive solenoid coil - Google Patents

Abstract

PURPOSE:To obtain a safe-in-strength, compact and economic superconductive solenoid coil by varying the radial direction thickness of each turn coil or each turn member according to electromagnetic force effected to each turn coil. CONSTITUTION:When only an insulation spacer 22 is installed between turn coils made of superconductive material 21, the radial direction thickness ti of each superconductive member 21 is determined by a formula (8). Here, Pi is electromagnetic pressure, ri is the radius of the superconductive member, te is the thickness in radial direction of the insulation spacer 22 and deltaa is the allowed stress of the superconductive material. If the superconductive coil wherein the radial direction thickness is determined in this way is effected by electromagnetic force Fr, the superconductive member 21 of each turn is displaced nearly equally to the direction of the radius and the circumferential stress generated by electromagnetic force also shows equal value within the allowed limit. Consequently, a sufficiently safe in strength and in stability of superconductivity and reliable superconductive solenoid coil can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in circular superconducting solenoid coils used at cryogenic temperatures.

[Technical background of the invention and its problems]

Conventionally, a circular superconducting solenoid coil as shown in Figure 1 (a
), (b) and the one shown in Figure 2 is particularly dilapidated. Figures 1 (,) and (b) show that multiple superelectric coils are each molded to obtain a number of turn coils with different radii, and these are formed into concentric circles in multiple stages (in this case, 3 coils). At the same time, insulating spacers 2, which are made of turn members such as reinforced plastic (FRP) and have the role of transmitting electromagnetic force Fr (to be described later) in the radial direction, are installed intermittently in the circumferential direction 3 between the turn coils. i. There are two turn coils and each turn coil is electrically connected. A bubble removal passage 4 is formed between the platform and the insulating spacer 2.

FIG. 2 is similar to the superconducting solenoid coil in FIG. 1, but instead of the insulating spacer 2 between the radial turn coils, reinforcement iμ made of, for example, stainless steel
The difference is that a turn member made of an insulating spacer 2 is placed between the material 5 and both 41.

By energizing the conventional superconducting solenoid coil configured as shown in FIGS. 1 and 2, each turn coil receives an electromagnetic force in the radial direction of the coil (hereinafter referred to as a radial direction of 11 mm) F. In addition to 'r (corresponding to 12 in FIG. 1), an electromagnetic force (hereinafter referred to as axial electromagnetic force) Fz (which cancels out 13 in FIG. 2) acts in the direction 7 of the coil 1111. In this case, the strength of the superconducting solenoid coil is
Generally, the radial electromagnetic force Fr is more dominant, and therefore, when considering the mechanical strength of a superconducting solenoid coil, only the radial frost and magnetic force Fr need to be considered.

Figure 3 shows the amount of radial displacement δr when a magnetic pressure square (corresponding to 8 in Figure 3) acts on the superconductor l in the radial direction.
i (convex to 9 in FIG. 3) and circumferential stress σqj, which are expressed as a 1d-order equation.

1-Pi2 δri=□...■ 1-ti Here, r is the radius of the superconductor (corresponding to 10 in Figure 3), and tl is the radius of the superconductor Jl (corresponding to 1 in Figure 3).
1)-.

EC indicates Young's modulus of the superconductor. Also, deep 1 represents the first turn from the inside. Generally, in a circular solenoid coil, the electromagnetic pressure block JPi is large on the inside and small on the outside, so the cross-sectional shape and radial thickness ti of the superconductor l are all the same as in the case of row 31 and FIG. The following problems occur in the 11th order.

(1) When Pi−r, 2>P1+1・r, +12, here the subscript;, i+1 represents the turn r of the 1st and 1st+1st stitches. So-called, Pi ”i > Pi+1 + ri
+1 (because ri> ri+1) σ0. 〉σ0. +1
becomes.

11. In IE, the stress of the innermost turn σq1nf: ♂
If each L5 horn is suppressed to σ, the outer turns will be safe in terms of brightness, but will have an excessive structure in terms of strength. A single solenoid coil, in its outer turns, has an electromagnetic pressure P
. U becomes negative, that is, super TJ,'(, ;, since it becomes a force that tries to shrink Q body 1 into 1111, '211self,) the point of 4M structure on the local side is I, Be complacent. Moreover, due to the installation 11, the coil design is unconventional.

When the coil installation dimensions are limited, the radial coil dimensions become large, which poses a major design problem.

(ii) Pl-r12< Pl-Ht-ri+12
o To @ ゛ and 1? In this case, δr1<δr1+1, and the outer turn change 11≦ is large. This means that every time the coil is energized, each superelectric,! ↓There is no need to show body 1d division behavior, I
l'r(?Ij, conductor, generates a crushing force in the space,
This may become a disturbance and cause a quench phenomenon (the transposition of a superconductor to a normal conductor), leading to the destruction of the superconductor.

[Purpose of the invention]

The present invention was developed in response to cancer in the above-mentioned 'US 'l'Fr, and is safe in terms of strength, and is effective in combating I.
11 resistance 'l1L24Z solenoid coil
(The aim is to [])

[Summary of the invention]

In order to achieve the above object, the present invention is designed to suppress stress in each turn coil within a permissible value and to make radial displacement of each turn coil substantially uniform. The wall thickness of the coil is changed according to the electromagnetic force applied to each turn coil6.
[Embodiments of the Invention] Hereinafter, the present invention will be explained with reference to embodiments shown in the drawings.First, a first embodiment of the present invention will be explained with reference to FIG. Figure 4 shows an example in which only insulating spacers 22 are provided between four turn coils formed by two superconductors, and the thickness of each superconductor 21 in the radial direction is determined as follows. It becomes.

That is, from the above formulas (■) and (■), if the circumferential stress σQin of the innermost layer superconductor 21 is the allowable stress σa, then the thickness ttnkJ of the innermost layer superconductor W1 body 21, Plnorin tin=□ ...■ σa Here Here, rin represents the radius of the innermost super-tuned body 21, and the subscript in represents the innermost turn. On the other hand, J: β electric ζ
In view of the stability of the seven coils, the radial displacement δr of the superconductor 2 in each turn must satisfy δr1≧δr1+1...■. Here, the subscripts i and i+1 represent the 1st and 1→-1th turns, respectively.

Substituting the formula (■) into the formula 0, the amount of displacement δFin of the innermost layer superconductor 21 is given by formula (■) as X6r=6 -δrin, then according to the formula 0, l P
++1 Thickness t in the radial direction of the first antagonist super'1iff isobody 21
1 is expressed as follows.

The radial thickness I7 of the insulating spacer 22 is set at t4. (constant), the radius r1'1 of the I-odd superconductor 21, and therefore the thickness ti of each superconductor 210 in the radial direction is determined according to the formula 0. As an example in Figure 4, Pin = 0.3
kgf/r+n + Pout := 0.031(q
f/mm + rtn = 300wn, te = 1 key turn number n 2 10. The conductor configuration in the case of σa-10 kgf/vn2 is shown. Determining from the superconductor plate thickness t1 and formula 0, t
in=9-+tout==134. The outer diameter of the coil is 367.97 mm.

Here, the subscript "out" represents the outermost layer turn.

As described above, the superconducting coil whose radial wall thickness dimension of each superconductor 21 is determined by Equation 0 is created by the electromagnetic force F
Even when r acts, the superconductor 21 of each turn is displaced almost uniformly in the radial direction, and the generated circumferential stress due to the electromagnetic force also exhibits a uniform value within the allowable stress value. Therefore, the superconducting solenoid coil is sufficiently safe and reliable in terms of strength and superconducting stability.

Moreover, the radial dimension of the entire coil can be kept compact, and the radial space of the entire superconducting solenoid coil can be utilized efficiently and efficiently.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 5 differs from FIG. 4 in that a turn h-material is provided between the turn coils formed by the superconductor 2). This turn member is made of stainless steel
In this case, the inner thickness of the reinforcing member 23 in the radial direction is determined as follows. The thickness of the superconductor 21 in the radial direction is tc, the electromagnetic pressure is Pi, the half f of the insulating spacer is the white circle in the direction -'te + the inner diameter of the innermost layer of the coil rin, J'ton is 1 "If the Young's modulus Ec of the body, the Young's modulus Es of the reinforcing decoration 23, and the allowable stress of the super'1a layer as a whole are σa,
The wall thickness tgi in the radial direction of the reinforcing V shank 423 is expressed by the formula 0.

Furthermore, a third embodiment of the present invention will be described with reference to FIG. As a superconductor, a stranded superconducting wire 25
It has a structure in which several wires are spirally wound around a stainless steel core 26 and wound in the circumferential direction.

In this case, the radial thickness of the stainless steel core 26 J'7. ts
This is a case where the reinforcing member 27 is wrapped around the outside like a stainless steel tape while c is constant, and 1d@force is P++1.
The radius wire diameter is dsc, the radial thickness of the insulating spacer 22 is te, and the diameter of the innermost layer of the coil is r11 + stainless steel core 2.
Assuming that the allowable stress σa is 6, the thickness of the reinforcing member in each turn in the radial direction is as shown in equation 0.

The thickness of the reinforcing member in the radial direction is determined based on this formula 0.

Next, a fourth embodiment of the present invention will be described with reference to FIG. In this case, the super'riLi'fi body has a structure in which several stranded superconducting wires 25 are wound around a wire around a nutless core 26 in the circumferential direction. be.

In the circumferential direction, a superconducting wire with such a flaming wire structure has a temperature of t"+'
Since it is considered that the stainless steel core 26 does not have lactic properties, the stainless steel core 26 serves as a reinforcing member. The radial thickness of the stainless steel core 26 is ti, the electromagnetic force is Pi, the twisted wire diameter is dsc, and the radial thickness of the insulating spacer 22 is te.

If the diameter of the innermost layer of the coil is rln + the allowable stress σa of the stainless steel core 26, then the equation 0 is obtained.

0 type f': shows the white horse jti in the radial direction of the ti-th stainless steel core 26.

〔Effect of the invention〕

According to the present invention described above, a superelectric solenoid coil is provided which is safe in terms of strength, 1) has a high reliability tL, has a compact overall rear direction dimension, and is economical. I can be worried.

[Brief explanation of the drawing]

1(a) and 1(b) are a perspective view and a plan view showing one groove of an example of a conventional superconducting solenoid, FIG. 2 is a perspective view showing a part of another example of a conventional superconducting solenoid, and FIG. The figure schematically shows the radial displacement and circumferential stress when an electromagnetic force acts on the super 1L body of Figures 1 and 2, and Figure 4 shows the first superconducting solenoid of the present invention. 5 to 7 are perspective views showing -b5 of second to fourth embodiments of the superconducting solenoid of the present invention. 21...Superconductor, 22...Insulating spacer, 25...
Superconducting wire with closed wire structure, 26...Stainless steel core, 27.
...Reinforcement member. Patent attorney Takehiko Suzue Figure 1 (a) Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] A plurality of superconducting conductors are individually molded to obtain a plurality of circular turn coils with different radii, and these are made into concentric circles, and turn members are provided between the turn coils to isolate each turn coil from each other. , and in a superconducting solenoid coil in which each turn coil is electrically connected,
Either the turn coil or the turn coil is one, and each wall thickness in the radial direction is changed in accordance with the electromagnetic force applied to each turn coil, and the stress of each turn coil is suppressed within an allowable stress value, and A superconducting solenoid coil characterized in that the radial displacement of the turn coil is almost uniform.