JP3198189B2 - Mounting structure of permanent current switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superconducting coil device used in a levitation railway, MRI, or the like, and more particularly, to a permanent current state (hereinafter, abbreviated as PC mode) of the device. And a mounting structure for a thermal permanent current switch (hereinafter abbreviated as PCS).

[0002]

2. Description of the Related Art FIG. 7 is a conceptual diagram of a closed loop circuit using a PCS. That is, when the PCS 1 is switched off, the current supplied from the external power supply 2 passes through the superconducting coil 3 and returns to the external power supply 2 again. But,
When the PCS 1 is switched on, the electric current flows permanently through the closed loop formed by the PCS 1 and the superconducting coil 3 because the electric resistance of the PCS 1 and the superconducting coil 3 is zero. Therefore, by turning on / off the PCS1, the PC mode can be generated or eliminated.

FIG. 8 is a partially broken sectional view showing the internal structure of PCS1. The superconducting wire 4 for PCS and the heater wire 5 are integrally impregnated in an impregnating agent 6, and these are covered with a case (reel) 7 made of glass fiber reinforced plastic (hereinafter abbreviated as FRP). Insulated from.
Reference numeral 8 denotes a terminal connected to the superconducting coil 3.

The operation of the PCS 1 is as follows. That is, when the heater wire 5 is energized to generate heat, the superconducting wire 4
Since the superconducting wire 4 is also heated, the superconducting state of the superconducting wire 4 is broken, and the superconducting wire 4 becomes a normal conducting state, and is turned off. Then, when the energization of the heater wire 5 is stopped, the superconducting wire 4 is cooled again by the surrounding liquid helium and enters a superconducting state,
The electric resistance becomes zero and the switch is turned on.

FIG. 9 is a partially broken sectional view showing a connection structure between PCS 1 and superconducting coil 3. In this figure,
A superconducting coil 3 (not shown) is accommodated in an internal flow passage 9a in the inner tank 9 and the internal flow passage 9a is filled with liquid helium. Reference numeral 10 denotes a fixing bracket having a mounting hole. A box 11 made of stainless steel is attached to the side of the inner tank 9, and the PCS 1 is stored in the box 11. In the box 11, the terminal 12 of the superconducting coil 3 pulled out from the inner tank 9 and the terminal 8 of the PCS 1 are connected.

Incidentally, since the PCS 1 is incorporated in the closed loop of the superconducting coil 3, it is placed in a strong magnetic field. Therefore, in order to stably maintain the superconducting state of PCS1, pay close attention to its attachment,
It is necessary to minimize heat generation and large magnetic field fluctuation due to generation of vibration and the like. FIG. 10 shows a PCS inside a box 11 which has been conventionally implemented in consideration of such circumstances.
1 is a cross-sectional view illustrating a mounting structure of FIG.

In FIG. 10, a support pipe 13 is attached to a box body 11 so as to pass therethrough. The PCS 1 is attached to the support pipe 13 via a pair of FRP flange members 14 and 15 functioning as spacers. Further, the flange portion of the support pipe 13 and the flange member 1
4, a coil spring 16 is interposed therebetween, and PC
S1 is strongly pressed to the right in FIG. 10 by the compressive force of the coil spring 16, and is in a state of being firmly fixed.

The reason why the coil spring 16 is used is as follows. In other words, the temperature inside the box 11 is reduced by cooling the liquid helium,
The heat shrinkage of the FRP forming the winding frame 7 and the flange members 14 and 15 of the CS1 is about 0.1% larger than the heat shrinkage of the stainless steel forming the box 11. . Therefore, if there is no coil spring 16, these PCS 1 and flange members 14, 15
Then, a minute gap is generated between the case 11 and the box 11.

When such a minute gap is generated, the PCS 1 is liable to cause a resonance phenomenon due to a force caused by a fluctuating magnetic field or an external vibration force. Then, due to this resonance phenomenon, the main body of the PCS 1 or the connection portions of the terminals 8 and 12 generate heat, and the superconducting state of the thermoconductive wire 4 of the PCS 1 is destroyed, and the function as the PCS 1 may be lost. Therefore, in order to prevent such a resonance phenomenon, a structure is adopted in which the PCS 1 is firmly fixed with the coil spring 16 interposed therebetween.

[0010]

SUMMARY OF THE INVENTION As described above, the PCS
In order to eliminate the difference in thermal contraction between the box 1 and the box 11, the PCS 1 is firmly attached using the compression force of the coil spring 16 in the conventional structure.

However, in the case of a floating railway, electromagnetic vibrations due to vibrations and harmonics during the running of the vehicle are applied, so that a considerably large vibration force and electromagnetic force are also applied to the inner tank 9 and the box 11. Will be.

In this case, since the inner tank 9 side is made of a strong load supporting material, the natural frequency is high, but the PCS 1 is fixed on the box 11 side via a spring system. Since the natural frequency of the PCS 1 is governed by the spring constant, it is not possible to obtain the same natural frequency as that of the inner tank 9. Therefore, as long as the configuration using the spring system is adopted, it has been difficult to stably maintain the superconducting state even with disturbance such as external vibration.

Here, it is conceivable that the natural frequency of the PCS 1 is raised to the same level as that of the inner tank 9 by using a spring member having a sufficiently large spring constant. However, for that purpose, the shape of this spring member must be made very large, and the box body 11 must also be made very large. In practice, it is impossible to adopt such a configuration. is there.

The present invention has been made in view of the above circumstances, and firmly fixes a PCS without using a spring member to increase its natural frequency, thereby causing disturbance such as external vibration. Another object of the present invention is to provide a PCS mounting structure capable of stably maintaining a superconducting state.

[0015]

Means for Solving the Problems As means for solving the above-mentioned problems, in the invention according to claim 1, an inner tank container containing a superconducting coil in an internal flow path filled with a cooling medium is provided. In a superconducting coil device in which a box housing a substantially donut-shaped permanent current switch is mounted and a terminal of the superconducting coil and a terminal of the permanent current switch are connected inside the box, the permanent current switch is connected to a central portion thereof. Is fixed to a supporting member of the box body penetrating through a spacer for restraining vibration in a penetrating direction, and the spacer is formed of a special polyethylene-based FRP having a property of expanding as the temperature decreases. It is characterized by having done.

According to the second aspect of the present invention, the first aspect is provided.
In the invention described above, the spacer is inserted between an outer peripheral surface of the support member and an inner peripheral surface of the permanent current switch, and a flange protruding to both end surfaces of the permanent current switch. It is characterized by having.

According to the third aspect of the present invention, there is provided the first aspect.
In the invention described above, the spacer encloses the outer peripheral surface of the permanent current switch and has a flange protruding toward both end surfaces of the permanent current switch.

According to the fourth aspect of the present invention, there is provided the first aspect.
In the invention described above, the spacer is divided into a plate-shaped first spacer abutting on one end face of the permanent current switch and a second spacer abutting on the other end face. The mounting structure of the permanent current switch.

[0019]

[0020]

In the structure of the first aspect of the present invention, when the temperature inside the box is reduced by the cooling medium, the permanent current switch and the box try to contract at different shrinkage rates, and a small amount A gap is about to form.

However, the special polyethylene-based FRP that forms the spacer has the property of expanding when the temperature decreases, so that the force for pressing the permanent current switch against the box and firmly fixing it is used. Increase. Therefore,
Even if the temperature is reduced by the cooling medium, the above-described minute gap does not occur, and the resonance phenomenon due to external vibration or the like can be prevented.

According to the individual circumstances such as the mounting space and the mounting state of the permanent current switch, an optimum configuration can be selected from the inventions according to claims 2 to 4 .

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. However, the same components as those in FIG. 10 are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 1 is a sectional view showing the structure of the first embodiment of the present invention. A special polyethylene FR is provided between the outer peripheral surface of the support pipe 13 and the inner peripheral surface of the PCS1.
A pair of spacers 101 and 102 formed of P are inserted. These spacers 101 and 102 are PCS1
Have flange portions 101a and 102a protruding toward the end face side. And, the flange portion 101a is the flange portion 13 of the support pipe 13.
a, and the flange 102a is in contact with the stainless steel fixing bracket 51.

FIG. 6 is a characteristic diagram showing the heat shrinkage of the special polyethylene-based FRP. As shown in this figure, general glass fibers thermally shrink by 0.15% or more in a low-temperature region of 50 ° K or less, and further shrink more in the case of a molded material.

On the other hand, the special polyethylene fiber is 50 ° K
Conversely, it has a characteristic of expanding 0.15% or more in the following low temperature range. In addition, stainless steel also has the property of thermally shrinking in a low temperature range of 50 ° K or less, but the value of the heat shrinkage is generally equal to that of the conventional FRP or 0.1% smaller. .

If the spacers 101 and 102 are formed by the special polyethylene-based FRP having the above-described characteristics, and the PCS 1 is fixed to the support pipe 13 through these, the fixing is not limited to the rigid fixing at normal temperature. However, in the low-temperature region, the rigid fixation can be made firmer than normal temperature.

That is, the PCS 1 can be rigidly fixed in a temperature range from a normal temperature to a low temperature range without using a spring system, and the natural frequency of the PCS 1 can be greatly increased as compared with the related art. Therefore, even if a force due to a fluctuating magnetic field or vibration is applied from the outside, the function as a permanent current switch can be stably exhibited without causing a resonance phenomenon.

FIG. 2 is a sectional view showing a second embodiment of the present invention. In FIG. 1, a pair of spacers 101, 1
However, the spacer 103 of this embodiment is formed in a single pipe shape having flange portions 103a at both ends.

FIG. 3 is a sectional view showing a first embodiment of the present invention. The spacers in FIG. 1 and FIG.
Although installed inside the PCS1, the pair of spacers 104 and 105 in this embodiment are in a state of enclosing the outer peripheral surface of the PCS1. In addition, 52 and 53 are fixing brackets.

FIG. 4 is a sectional view showing a second embodiment of the present invention. In FIG. 3, a pair of spacers 104, 1
However, the spacer 106 of this embodiment is formed in a single ring shape having flanges at both ends.

FIG. 5 is a sectional view showing an embodiment of the present invention. In this embodiment, a pair of flat spacers 107 and 108 are in contact with the end face of the PCS 1 and are firmly fixed between the flange 13 a of the support pipe 13 and the fixture 54.

[0033]

Further, in the above embodiment, the bobbin 7 of the PCS 1 is constituted by a single member, but it may be a para-structure in which this is divided into several members.

[0035]

As described above, according to the first aspect of the present invention, since the spacer or the case of the PCS is made of a special polyethylene-based FRP having a property of expanding in a low-temperature region, the spring member can be used. The PCS can be firmly fixed without using it, and its natural frequency can be increased. Therefore, even when disturbance such as external vibration occurs, the superconducting state can be stably maintained.

According to the second to fourth aspects of the present invention, an optimum mounting structure can be selected from the mounting structures according to each mounting situation.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a first embodiment of the invention described in claim 2;

FIG. 2 is a sectional view showing the configuration of a second embodiment of the invention described in claim 2;

FIG. 3 is a sectional view showing the configuration of a first embodiment of the invention described in claim 3;

FIG. 4 is a sectional view showing the configuration of a second embodiment of the invention described in claim 3;

FIG. 5 is a sectional view showing the configuration of an embodiment of the invention described in claim 4.

FIG. 6 is a characteristic diagram showing the heat shrinkage of a special polyethylene-based FRP.

FIG. 7 is a conceptual diagram of a closed loop circuit using a PCS.

FIG. 8 is a partially crushed sectional view showing the internal structure of the PCS.

FIG. 9 is a partially broken cross-sectional view showing a connection structure between a PCS and a superconducting coil.

FIG. 10 is a sectional view showing a conventional mounting structure of a PCS.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Permanent current switch (PCS) 3 Superconducting coil 9 Inner vessel container 11 Box 13 Support pipe 101-108 Special polyethylene FRP spacer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 39/16 H01L 39/04 H01F 6/06

Claims (4)

(57) [Claims] 1. A box housing a substantially donut-shaped permanent current switch is attached to an inner tank container housing a superconducting coil in an internal flow path filled with a cooling medium, and a terminal portion of the superconducting coil inside the box. And a terminal portion of the permanent current switch, wherein the permanent current switch is connected to a support member of the box penetrating a center portion thereof through a spacer for restraining vibration in a penetrating direction. A permanent current switch mounting structure, wherein the spacer is formed of a special polyethylene-based FRP that is fixed and expands as the temperature decreases. 2. The mounting structure for a permanent current switch according to claim 1, wherein said spacer is inserted between an outer peripheral surface of said support member and an inner peripheral surface of said permanent current switch. A permanent current switch mounting structure comprising a flange protruding toward both end faces of the permanent current switch. 3. The permanent current switch mounting structure according to claim 1, wherein the spacer encloses an outer peripheral surface of the permanent current switch, and has a flange protruding toward both end surfaces of the permanent current switch. A mounting structure for a permanent current switch, comprising: 4. The mounting structure for a permanent current switch according to claim 1, wherein the spacer is in contact with a first plate-shaped spacer in contact with one end face of the permanent current switch, and in contact with the other end face. A mounting structure for a permanent current switch, wherein the mounting structure is divided into a second spacer and a second spacer.