JP2011171631A - Resin impregnating method for superconducting coil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin impregnating method for a superconducting coil, which is capable of uniformly impregnating a resin into the entire superconducting coil by a comparatively simple method and preventing the occurrence of a void in the resin, thereby preventing the occurrence of a quench phenomenon. <P>SOLUTION: The resin impregnating method for the superconducting coil 1 for impregnating an epoxy resin 8 into the superconducting coil 1 formed by winding a superconducting wire material 3 around a cylindrical winding frame 2 includes: a vacuum drawing step for vacuum-drawing the inside of a container 5 into which the superconducting coil 1 is put; a resin injecting step for injecting the liquid epoxy resin 8 into the vacuum-drawn container 5; and a rotating heating step for heating the superconducting coil 1 taken out of the container 5 in which the epoxy resin 8 is injected while rotating the coil centered at a shaft of the winding frame 2 in a state where the axial direction A of the winding frame 2 is substantially horizontal. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for impregnating a superconducting coil.

  In general, in a superconducting coil wound with a superconducting wire, the superconducting wire may physically move due to the interaction between an energized current and a magnetic field generated by itself when excited. When the superconducting wire moves in this way, there is a problem that the temperature of the superconducting wire rises due to frictional heat or the like, causing a quench phenomenon that shifts from the superconducting state to the normal conducting state. For this reason, the superconducting wires are fixed with a resin such as an epoxy resin.

  As a method for fixing the superconducting wires with the resin such as the epoxy resin, there is a method of applying a resin or the like to the superconducting wire while winding the superconducting wire as described in Patent Document 1.

  When the resin or the like is applied to the superconducting wire while winding the superconducting wire in this way, it is possible to fill and fix the resin to the superconducting wire without excess or deficiency by adjusting the amount of resin applied. For this reason, it is possible to make it difficult to form a bridge made of excess resin between the superconducting wire and the flange provided on the superconducting coil, and the occurrence of the quench phenomenon can be prevented.

  However, when resin or the like is applied to the superconducting wire while winding the superconducting wire, voids (voids) may be generated in the resin. If stress such as cooling restraint thermal stress or electromagnetic force during excitation is concentrated on the void, a crack is generated in the resin fixed between the superconducting wires. As described above, there is a problem that the resistance of the superconducting wire rapidly rises due to the cracks generated in the resin and causes a quench phenomenon in which the superconducting state shifts to the normal conducting state.

  In this regard, Patent Document 2 describes a vacuum impregnation method in order to minimize residual voids in the superconducting wire. In this vacuum impregnation method, a superconducting wire is impregnated with a resin in a vacuum, thereby preventing gas from entering the superconducting wire and preventing voids from being generated in the resin.

JP 2001-006922 A JP 2007-234692 A

  However, in the method described in Patent Document 2, since the resin is cured in a state where the superconducting coil is immersed in the resin solution, a surplus appears in the resin fixed around the superconducting coil. And the surplus of this resin forms a bridge etc. between a superconducting wire and the flange provided in the superconducting coil, and causes a quench phenomenon. In order not to form such a bridge or the like, it takes time and effort to remove the resin surplus that is once fixed around the superconducting coil and hardened.

  Therefore, the present invention has been made to solve the above-described problems, and its purpose is to impregnate the resin evenly over the entire superconducting coil by a relatively simple method and to form voids in the resin. It is an object of the present invention to provide a method for impregnating a superconducting coil that can prevent the occurrence of quenching and thus the occurrence of a quench phenomenon.

  A first invention for solving the above-described problem is a superconducting coil impregnation method in which a superconducting coil obtained by winding a superconducting wire around a cylindrical winding frame is impregnated with an epoxy resin, the container containing the superconducting coil A vacuum drawing step of evacuating the inside, a resin injection step of injecting a liquid epoxy resin into the vacuumed container, and the superconducting coil taken out from the container into which the epoxy resin has been injected, A method of impregnating the superconducting coil, comprising: a heating step of heating while rotating about the axis of the reel in a state where the axial direction is substantially horizontal.

  According to said process, the excess water | moisture content adhering to the superconducting coil can be removed by passing through a vacuum drawing process. In addition, since the epoxy resin is injected into the container kept in a vacuum state in the resin injection step, generation of voids in the epoxy resin can be prevented. Thereby, generation | occurrence | production of the quench phenomenon resulting from the void in an epoxy resin can be prevented.

  Furthermore, the epoxy resin can be uniformly impregnated over the entire superconducting coil through the rotary heating process. Thereby, it is possible to make it difficult to form an extra epoxy resin bridge between the superconducting wire and the winding frame of the superconducting coil, and it is possible to prevent the occurrence of a quench phenomenon due to the bridge.

  Moreover, 2nd invention is the impregnation method of the superconducting coil which concerns on 1st invention, Comprising: In the said rotation heating process, the said superconducting coil is mounted on a some roller, and the said some roller is rotated. Thus, the superconducting coil impregnation method is characterized in that the superconducting coil is rotated.

  According to said process, a superconducting coil can be rotated comparatively easily only by mounting a superconducting coil on a some roller. Thereby, an epoxy resin can be uniformly impregnated over the whole superconducting coil by a relatively simple method.

  A third invention is a method for impregnating a superconducting coil according to the second invention, wherein the superconducting coil having a disk attached to a flange provided on the winding frame is placed on a plurality of rollers. Then, the superconducting coil impregnation method is characterized in that the superconducting coil is rotated by rotating the plurality of rollers.

  According to said process, the superconducting coil which attached the disc to the flange provided in the winding frame is mounted on a plurality of rollers, and the superconducting coil can be rotated by rotating the plurality of rollers. it can. Thereby, it can prevent reliably that the part of the superconducting wire of a superconducting coil contacts a roller.

  Further, a fourth invention is a method for impregnating a superconducting coil according to the first invention, wherein in the rotating heating step, a rotating member is inserted into an inner space of the winding frame to rotate the superconducting coil. A superconducting coil impregnation method is characterized.

  According to the above process, the superconducting coil can be rotated by inserting the rotating member into the inner space of the winding frame. Thereby, a superconducting coil can be rotated only using the middle space part of a winding frame. For example, it is effective when it is not desired to contact the outside of the superconducting coil with a roller or the like.

  A superconducting coil impregnation method capable of impregnating an epoxy resin evenly over the entire superconducting coil by a relatively simple method and preventing voids from being generated in the epoxy resin, thereby preventing the occurrence of a quench phenomenon. Can be provided.

It is a graph which shows the viscosity change accompanying the time passage of an epoxy resin. It is a graph which shows the viscosity change accompanying the temperature change of an epoxy resin. It is explanatory drawing explaining the vacuuming process which concerns on 1st Embodiment. It is explanatory drawing explaining the resin injection | pouring process which concerns on 1st Embodiment. It is explanatory drawing explaining the extraction process and 1st cleaning which concern on 1st Embodiment. It is explanatory drawing explaining the rotation heating process which concerns on 1st Embodiment. It is explanatory drawing explaining the 2nd cleaning which concerns on 1st Embodiment. It is explanatory drawing explaining the reheating process which concerns on 1st Embodiment. It is explanatory drawing explaining the rotation heating process in 2nd Embodiment. It is explanatory drawing explaining the rotation heating process in 3rd Embodiment.

(First embodiment)
Hereinafter, a first embodiment for carrying out the present invention will be described with reference to the drawings. The present invention is realized as a method of impregnating a superconducting coil with an epoxy resin.

  First, with reference to FIG.1 and FIG.2, the characteristic of the epoxy resin used by this embodiment is demonstrated. FIG. 1 is a graph showing changes in viscosity of an epoxy resin over time. FIG. 2 is a graph showing a change in viscosity accompanying a change in temperature of the epoxy resin.

  The epoxy resin 8 used for impregnating the superconducting wire 3 of the superconducting coil 1 according to the present embodiment has a characteristic of causing a viscosity change with time as shown in FIG. Here, the horizontal axis in FIG. 1 represents the elapsed time (h) from the start of the chemical reaction between the epoxy resin and the curing accelerator. Moreover, the vertical axis | shaft in FIG. 1 represents the viscosity (mPa * s) of an epoxy resin. Moreover, the epoxy resin which showed the characteristic of FIG. 1 was hold | maintained in the state of 50 degreeC, and the chemical reaction of an epoxy resin and a hardening accelerator was started. In addition, the viscosity change with the passage of time has the property that when the temperature of the epoxy resin is high, the speed at which the viscosity increases becomes faster. In addition, there is a property that the speed at which the viscosity of the epoxy resin increases due to the content of the curing accelerator increases. Furthermore, the viscosity that can be used for impregnation is up to a value of 1500 mPa · s, and beyond this, the viscosity is not suitable for impregnation. And in this embodiment, as shown in FIG. 1, 9 hours which are elapsed time until it reaches 1500 mPa * s are pot times which an epoxy resin can use for impregnation.

  Next, with reference to FIG. 2, the viscosity change accompanying the temperature change of the epoxy resin used by this embodiment is demonstrated. Here, the horizontal axis in FIG. 2 represents the temperature (° C.) of the epoxy resin. Moreover, the vertical axis | shaft in FIG. 2 represents the viscosity (mPa * s) of an epoxy resin. 2 uses the epoxy resin at the time when the chemical reaction between the epoxy resin and the curing accelerator is started (“0h” in FIG. 1). That is, as shown in FIG. 2, it shows a value of 70 mPa · s at 50 ° C. Referring to FIG. 2, it can be seen that the viscosity decreases as the temperature of the epoxy resin increases, and the viscosity increases as the temperature of the epoxy resin decreases. For example, when the temperature of the epoxy resin rises to 80 ° C., the viscosity decreases to 20 mPa · s and becomes a smooth liquid. Further, when the temperature of the epoxy resin is lowered to 10 ° C., the viscosity rises to 1600 mPa · s and cannot be used for impregnation.

  As described above, the viscosity change with time of the epoxy resin is irreversible, and the viscosity change with the temperature change of the epoxy resin is reversible. However, the epoxy resin cured after a certain amount of time hardly undergoes a change in viscosity accompanying a change in temperature. Therefore, basically, after the chemical reaction between the epoxy resin and the accelerator is initiated, the epoxy resin gradually cures from liquid to semi-solid and from semi-solid to solid. To go.

(Superconducting coil impregnation method)
Next, the impregnation method of the superconducting coil 1 in this embodiment will be described. The superconducting coil 1 according to this embodiment is impregnated with the epoxy resin 8 having the characteristics described above through the following steps. FIG. 3 is an explanatory view for explaining the vacuuming process. FIG. 4 is an explanatory view for explaining the resin injection step. FIG. 5 is an explanatory diagram for explaining the extraction process and the first cleaning. FIG. 6 is an explanatory diagram for explaining the rotary heating process. FIG. 7 is an explanatory diagram for explaining the second cleaning. FIG. 8 is an explanatory diagram for explaining the reheating step.

  First, the superconducting wire 3 is wound by applying tension with the cylindrical winding frame 2 as a core. Thereafter, as shown in FIG. 3, the superconducting coil 1 in a state where the superconducting wire 3 is wound around the winding frame 2 is housed in a vacuum heating furnace 6 in a state where it is put in a metal container 5.

  Next, as shown in FIG. 3, the inside of the vacuum heating furnace 6 is evacuated using the vacuum pump 7 while the temperature inside the vacuum heating furnace 6 is heated to about 100 ° C. (evacuation process). Thereafter, the temperature in the vacuum heating furnace 6 is lowered to 60 ° C. while maintaining the vacuum state in the vacuum heating furnace 6. After the vacuuming step, moisture adhering between the superconducting wires 3 wound around the winding frame 2 can be removed by evaporation.

  On the other hand, the liquid epoxy resin 8 used for impregnation of the superconducting coil 1 is mixed with a curing accelerator in the storage tank 9, heated to 50 ° C. to 70 ° C. and stirred and evacuated to form a liquid epoxy resin. Air or the like dissolved in 8 is defoamed.

  Next, as shown in FIG. 4, a liquid epoxy resin 8 is poured from a storage tank 9 into a container 5 in a vacuum heating furnace 6 held in a vacuum, and the superconducting wire 3 of the superconducting coil 1 and between the superconducting wires 3. The epoxy resin 8 is infiltrated (resin injection step). Here, in this embodiment, the viscosity suitable for pouring the liquid epoxy resin 8 into the container 5 is set to about 100 mPa · s. Therefore, the time during which the liquid epoxy resin 8 can be poured into the container 5 is 5 hours (h) after the start of the chemical reaction between the epoxy resin and the curing accelerator as shown in FIG. Until the viscosity reaches 100 mPa · s). In order to achieve good impregnation with the epoxy resin 8 within 5 hours, pressurization and depressurization are repeated as necessary.

  Thereafter, while the temperature in the vacuum heating furnace 6 is lowered to about 10 ° C. to 20 ° C., the process waits until the viscosity of the epoxy resin 8 becomes approximately 1500 mPa · s or more. When the viscosity of the epoxy resin 8 is about 1500 mPa · s, the epoxy resin 8 does not flow out of the superconducting coil 1 in a short time. In addition, at this stage, it is calculated | required that the viscosity of the epoxy resin 8 exists in the range of 1500 mPa * s or more and 10,000 mPa * s or less. If it is the viscosity of the said range, it can wipe off sufficiently with the cloth 10 etc. in the 1st cleaning demonstrated in the following paragraph. On the contrary, if the viscosity exceeds 10,000 mPa · s, it cannot be easily wiped off with the cloth 10 or the like.

  Next, as shown in FIG. 5, the superconducting coil 1 is taken out from the container 5 and the vacuum heating furnace 6 (extraction process). Then, as shown in FIG. 5, the excess epoxy resin 8 attached to the taken out superconducting coil 1 is wiped off with a cloth 10 or the like (first cleaning). The viscosity of the epoxy resin 8 attached to the superconducting coil 1 taken out is in the range of 1500 mPa · s or more and 10000 mPa · s or less.

  Next, as shown in FIG. 6, the superconducting coil 1 is laid sideways so that the axial direction A of the winding frame 2 is substantially horizontal. Next, the superconducting coil 1 is placed on the turning roller 11 contained in the heating furnace 12 so that the flanges 4a and 4b of the superconducting coil 1 are in contact with the outer periphery of the turning roller 11 (roller). Subsequently, as shown in FIG. 6, the turning roller 11 is rotated to rotate the superconducting coil 1 around the axis of the winding frame 2. At this time, the rotation speed at which the superconducting coil 1 rotates is set to such a speed that the liquid of the epoxy resin 8 inside the superconducting wire 3 of the superconducting coil 1 is canceled at any time due to gravity. For example, if the viscosity of the epoxy resin 8 attached to the superconducting coil 1 taken out is 1500 mPa · s, the rotational speed at which the superconducting coil 1 rotates may be about 2 rpm to 20 rpm. Although not shown, the turning roller 11 uses a rotary motor as a rotational power source.

  Then, as shown in FIG. 6, in the heating furnace 12, the superconducting coil 1 is heated at around 60 ° C. to 90 ° C. while being rotated on the turning roller 11 (rotary heating process). At this time, the epoxy resin 8 liquid impregnated in the superconducting wire 3 of the superconducting coil 1 may flow out due to the viscosity change accompanying the temperature change of the epoxy resin shown in FIG. It may be adjusted for convenience (in this embodiment, for example, the rotational speed is increased from 2 rpm to 6 rpm). Thereafter, heating is performed until the epoxy resin 8 impregnated in the superconducting wire 3 of the superconducting coil 1 becomes semi-solid. Here, when the epoxy resin 8 is semi-solidized, its appearance is a viscous liquid or jelly-like, the property is increased in adhesiveness, and the viscosity is immediately before solidification from 500,000 mPa · s (500 Pa · s). The state up to the stage having the viscosity of Once the epoxy resin 8 becomes semi-solid, the epoxy resin 8 impregnated in the superconducting wire 3 of the superconducting coil 1 does not flow out. Here, when the epoxy resin 8 becomes semi-solid and the appearance thereof becomes a viscous liquid or a jelly, it is in a state such as “coal tar before solidification” or “torimochi”.

  Thereafter, when the epoxy resin 8 impregnated in the superconducting wire 3 of the superconducting coil 1 becomes semi-solid, heating and turning of the turning roller 11 are stopped, and heating and rotation of the superconducting coil 1 are stopped. Then, as shown in FIG. 7, the excess epoxy resin 8 attached to the superconducting coil 1 is scraped off using a spatula 15 or the like (second cleaning). In addition, since a sufficient excess amount of the epoxy resin is removed by the first cleaning, the amount and range of the epoxy resin 8 to be removed can be reduced in the second cleaning. That is, the work is such that the shape of the epoxy resin 8 impregnated on the outer periphery of the superconducting wire 3 is adjusted. Note that the second cleaning may be omitted.

  Note that the second cleaning is possible even when the epoxy resin 8 is gelled beyond the semi-solid mucous or jelly form in the rotary heating process. In this case, it can be easily removed by peeling off the gelled epoxy resin 8 with a scraper or the like. Here, the gel state is a state in which the solidification has progressed more than the semi-solidified viscous liquid or jelly shape, and is a state in which there is no strength and can be easily peeled off by a scraper or the like.

  Next, as shown in FIG. 8, the superconducting coil 1 is heated again in the heating furnace 12 (reheating step). The heating temperature at this time is higher than the heating temperature of 60 ° C. to 90 ° C. in the rotary heating process described above. Specifically, heating is performed at 100 to 150 ° C. for 12 to 24 hours. Thereby, the epoxy resin 8 impregnated in the superconducting wire 3 of the superconducting coil 1 can be solidified and solidified. That is, sufficient strength can be given to the epoxy resin 8.

  Through the above steps, the superconducting coil 1 is impregnated with the epoxy resin 8.

  According to the method for impregnating the superconducting coil 1 described above, excess water adhering to the superconducting coil 1 can be removed through the vacuuming step. Further, since the epoxy resin 8 is injected into the container 5 kept in a vacuum state in the resin injection step, generation of voids in the epoxy resin 8 can be prevented. Thereby, generation | occurrence | production of the quench phenomenon resulting from the void in the epoxy resin 8 can be prevented.

  Furthermore, the epoxy resin 8 can be uniformly impregnated over the entire superconducting coil 1 through the rotary heating process. As a result, it is possible to make it difficult to form a bridge made of excess epoxy resin 8 between the superconducting wire 3 and the winding frame 2 of the superconducting coil 1, and the occurrence of a quenching phenomenon caused by the bridge can be prevented. .

  Further, in the rotary heating process, the superconducting coil 1 can be easily rotated by simply placing the superconducting coil 1 on the two turning rollers 11. Thereby, the epoxy resin 8 can be uniformly impregnated over the entire superconducting coil 1 by a relatively simple method.

(Second Embodiment)
Hereinafter, a superconducting coil impregnation method according to a second embodiment for carrying out the present invention will be described with reference to the drawings. In addition, description is abbreviate | omitted for the location similar to 1st Embodiment, and it demonstrates centering around a different structure. FIGS. 9A and 9B are explanatory views for explaining the rotation heating process in the second embodiment.

  In the first embodiment, the superconducting coil 1 is placed on the turning roller 11 so that the flanges 4a and 4b of the superconducting coil 1 are in contact with the outer periphery of the turning roller 11, and as shown in FIG. To rotate the superconducting coil 1. However, in the second embodiment, as shown in FIG. 9, the superconducting coil 1 is placed on the turning roller 11 after the disks 20 a and 20 b are attached to the flanges 4 a and 4 b provided on the winding frame 2. It is on.

  In the superconducting coil impregnation method in the second embodiment, the superconducting coil 1 in which the disks 20a and 20b are attached to the flanges 4a and 4b provided on the winding frame 2 is placed on the turning roller 11, and the turning roller The superconducting coil 1 can be rotated by rotating 11. Thereby, it can prevent reliably that the part of the superconducting wire 3 of the superconducting coil 1 contacts the turning roller 11. Further, for example, when the height from the winding frame 2 of the superconducting wire 3 wound around the winding frame 2 to the outer periphery of the superconducting wire 3 is higher than the protruding height of the flanges 4a and 4b from the winding frame 2, It is effective to attach 20a and 20b to the flanges 4a and 4b.

(Third embodiment)
Hereinafter, a superconducting coil impregnation method according to a third embodiment for carrying out the present invention will be described with reference to the drawings. In addition, description is abbreviate | omitted for the location similar to 1st Embodiment or 2nd Embodiment, and it demonstrates centering around a different structure. FIGS. 10A and 10B are explanatory views for explaining the rotation heating process in the third embodiment.

  In the first and second embodiments, the superconducting coil 1 is rotated by rotating the turning roller 11. However, in the third embodiment, as shown in FIG. 10B, the rotating member 33 protruding from the rotating device 31 is inserted into the middle space of the cylindrical winding frame of the superconducting coil 30 to rotate the superconducting coil 30. The configuration is to let Further, after inserting the rotating member 33 into the superconducting coil 30, the superconducting coil 30 is fixed to the rotating member 33 by tilting the stopper 34 attached to the tip of the rotating member 33 outward (FIG. 10 ( a)).

  In the superconducting coil impregnation method in the third embodiment, as shown in FIG. 10B, the rotating member 33 can be inserted into the space inside the winding frame of the superconducting coil 30 to rotate the superconducting coil 30. Thereby, the superconducting coil 30 can be rotated using only the middle space portion of the cylindrical winding frame. For example, it is effective when a plurality of flanges 31a, 32b, 32c, and 32d provided on the winding frame of the superconducting coil 30 are not desired to come into contact with a roller or the like.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims.

1 Superconducting coil 2 Reel 3 Superconducting wire 5 Container 8 Epoxy resin 11 Turning roller A Axial direction of reel

Claims (4)

A superconducting coil impregnation method in which a superconducting coil formed by winding a superconducting wire around a cylindrical winding frame is impregnated with an epoxy resin,
A vacuuming step of evacuating the inside of the container containing the superconducting coil;
A resin injection step of injecting a liquid epoxy resin into the evacuated container;
A rotational heating step of heating the superconducting coil taken out from the container into which the epoxy resin has been injected while rotating about the axis of the reel in a state where the axial direction of the reel is substantially horizontal;
A method for impregnating a superconducting coil, comprising: A method for impregnating a superconducting coil according to claim 1,
In the rotational heating step, the superconducting coil is impregnated by placing the superconducting coil on a plurality of rollers and rotating the plurality of rollers to rotate the superconducting coil. A superconducting coil impregnation method according to claim 2,
A superconducting coil characterized in that the superconducting coil having a disk attached to a flange provided on the winding frame is placed on a plurality of rollers, and the superconducting coil is rotated by rotating the plurality of rollers. Coil impregnation method. A method for impregnating a superconducting coil according to claim 1,
A superconducting coil impregnation method, wherein, in the rotary heating step, a rotating member is inserted into an inner space of the winding frame to rotate the superconducting coil.