JP2000294087A - Resin molded vacuum valve - Google Patents

Abstract

(57) [Summary] To provide a vacuum valve which is excellent in crack resistance against temperature change and can be miniaturized. An insulating cylinder and a fixed end plate of a vacuum valve are provided.
A first fiber layer 12 is formed by winding a glass fiber roving material around the outer periphery of the first fiber layer. Similarly, a roving material is wound around the outer periphery of the first fiber layer 12 at a coarse pitch to form a second fiber layer 13. The vacuum valve formed with these fiber layers is put into a casting mold, and an epoxy resin is injected to form a casting resin layer 14 on the outer periphery of the vacuum valve 1. By forming a resin layer having a high glass fiber density and a low coefficient of thermal expansion on a portion near the outer periphery of the insulating cylinder 2,
Prevents separation at the interface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum valve used for shutting off or opening a power and power distribution system, and more particularly to a resin-molded vacuum valve.

[0002]

2. Description of the Related Art As a switch for a switchgear or a motor of a power system or a power distribution system, a vacuum valve having a vacuum cutoff unit is used. FIG. 6 is a longitudinal sectional view showing an example of a conventional vacuum valve.

[0003] In FIG. 6, a vacuum vessel 1 is formed by sealing both ends of an insulating cylinder 2 made of an inorganic material such as ceramics or glass by brazing a fixed end plate 3 and a movable end plate 4. The fixed conductor shaft 6 is fixed to the fixed end plate 3 by brazing so as to maintain a vacuum-tight state, and the movable conductor shaft 7 passes through the movable end plate 4 via the bellows 8. The contact 9 is opened and closed while maintaining the vacuum.

[0004] The vacuum valve 1 uses a high vacuum that has an excellent dielectric strength against a high voltage inside the insulating cylinder 2.
The arc generated when the contact 9 opens and closes in this high vacuum is immediately extinguished to cut off the circuit.

As described above, since the vacuum valve 1 opens and closes the contacts 9 in a high vacuum, the electrode opening / closing distance required to cut off the high-voltage circuit can be shortened, and the outer shape of the insulating cylinder 2 in which the electrodes are housed is small. Can be

However, when the insulating cylinder 2 is miniaturized, the creepage distance of the outer surface becomes short, and the creepage distance can be used for a low voltage. However, when the rated voltage is high, a predetermined withstand voltage cannot be obtained with a short creepage distance.

Therefore, SF having higher dielectric strength than air is used.
_{6 The} gas is incorporated in a box filled with the gas, or the outer periphery of the insulating cylinder 2 is integrally formed by insulating molding with epoxy resin or the like.

However, in the structure in which the vacuum valve 1 is integrally formed by casting an epoxy resin or the like, since the thermal expansion coefficient of the resin of the insulating molding jacket and the thermal expansion coefficient of the insulating cylinder 2 made of an inorganic material are different, the energization is not performed. And the thermal stress due to the temperature difference after the power supply is stopped, there is a possibility that cracks may occur in the insulating jacket during long-term operation, and thus the reliability is reduced.

Therefore, in order to prevent such cracks, a vacuum valve having a structure integrally formed by insulating molding as shown in a vertical sectional view of FIG. 7 is employed. In the resin-molded vacuum valve shown in FIG. 7, a buffer layer 10 of a rubber-like elastic material such as a thermoplastic epoxy resin or a urethane resin is provided on the outer periphery of a vacuum vessel 5, and an insulating casing 11 of an epoxy casting resin is formed outside the buffer layer. are doing.

In this vacuum valve, the vacuum vessel 5 is wrapped with a soft and flexible epoxy resin to a thickness of several millimeters, and a buffer layer 10 is first formed. A two-stage molding method is employed in which a predetermined size and shape are formed by casting.

[0011]

However, as an environmental measure, in particular, as a measure to prevent global warming, SFs having excellent insulating properties have been developed.
_Six gases have become a problem, and it has become mandatory to reduce or recover this SF ₆ gas.

[0012] The SF ₆ gas, varies the pressure, because having about 3 times the dielectric strength of the air, the SF ₆
In order to adopt it for a high-voltage circuit breaker or switchgear that does not use gas, it is necessary to form an insulating jacket 11 on the outer periphery of a vacuum valve.

However, in the conventional two-stage molding method, it is necessary to first provide the buffer layer 10 having a predetermined thickness, and further, equipment and curing conditions different from those of the conventional casting resin are required. Go down.

Further, since a new adhesive interface is formed between the epoxy resin for casting and the buffer layer, it is liable to be a weak point in manufacturing. For this reason, the casting process requires strict quality control, increases the load on facilities and work, and makes the work process complicated, which is not economical.

In addition, in order to reduce the stress generated at the interface with the outer periphery of the insulating cylinder, the casting resin is filled with inorganic particles and glass fibers to reduce the linear expansion coefficient of the casting resin and increase the strength. There is also a method of manufacturing with a single casting, but if a large amount of filler such as fiber is mixed into the casting resin, the viscosity of the casting resin increases, the fluidity and the defoaming property decrease, Since filtration such as removal cannot be performed, quality control becomes more difficult. Therefore, an object of the present invention is to provide a resin-molded vacuum valve which has excellent crack resistance and can be downsized.

[0016]

According to a first aspect of the present invention, there is provided a resin-molded vacuum valve, comprising: an inner fiber layer formed on an outer periphery of an insulating cylinder accommodating a fixed contact and a movable contact; An outer fiber layer formed on the outer periphery of the inner fiber layer and forming a larger gap between the fibers of the inner fiber layer, and the inner fiber layer and the outer fiber layer are impregnated and cured to adhere to the outer periphery of the insulating cylinder. An insulating layer is provided.

According to a second aspect of the present invention, there is provided a resin-molded vacuum valve, wherein the inner fiber layer and the outer fiber layer are formed by winding a glass roving material. A resin-molded vacuum valve according to a third aspect of the present invention is characterized in that the inner fiber layer and the outer fiber layer are formed by glass tape.

According to a fourth aspect of the present invention, there is provided a resin-molded vacuum valve, wherein the inner fiber layer and the outer fiber layer are formed by a plurality of glass sleeves. A resin-molded vacuum valve according to a fifth aspect of the present invention is characterized in that the inner fiber layer and the outer fiber layer are formed of a cylindrical glass nonwoven fabric or glass felt.

According to a sixth aspect of the present invention, there is provided a resin-molded vacuum valve, wherein a polyester fiber is used for a warp of a glass tape. According to a seventh aspect of the present invention, the insulating layer is formed by casting an epoxy resin containing 70 to 75% by weight of a particulate fused silica filler and 2 to 5% by weight of spherical silica fine particles. It is characterized by having done.

The resin-molded vacuum valve of the invention according to claim 8 is characterized in that a glass tape, a glass sleeve, or a glass nonwoven fabric is impregnated with epoxy resin in a B-stage state.

According to the invention, the insulating layer having a high fiber density and a low coefficient of thermal expansion is formed on the insulating cylinder side inside the insulating layer. On the outer peripheral side of the insulating layer, an insulating layer in which the fiber density is low and the thermal expansion coefficient gradually increases is formed.

In the invention corresponding to claim 6, the fibers are shrunk by heat at the time of molding the resin, and are brought into close contact with the outer periphery of the insulating cylinder. In the invention corresponding to claim 8, after the resin in a low viscosity state is sufficiently penetrated between the fibers, the state is changed to the B stage state.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the resin-molded vacuum valve of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a first embodiment of a resin-molded vacuum valve of the present invention, and corresponds to claims 1 and 2 and corresponds to FIG. 7 shown in the prior art.

In FIG. 1, this resin-molded vacuum valve comprises a fiber layer 12 (described later) in which a high-strength glass roving material made of glass fiber is wound around the outer periphery of a vacuum vessel 5 of the vacuum valve 1. A second fiber layer 13 is formed, and an epoxy resin casting resin layer 14 is integrally formed on the outer periphery thereof.

That is, a glass roving material composed of a plurality of glass fibers is spirally wound at a pitch slightly wider than the width of the glass roving material so that the casting resin is impregnated between the glass roving materials. After the first fiber layer 12 is formed, the second roving layer 13 is formed by further widening and winding the feed pitch of the glass roving material.

Next, it is put into a mold, and after evacuation, a few μm
Bisphenol A type epoxy casting resin mixed with 2 to 5% of spherical silica fine particles of diameter and 70 to 75% of particulate fused silica filler is cast at 80 ° C, pressurized at about 0.3 MPa, and primary cured in a curing furnace. After curing, it is secondarily cured after release and integrated.

FIG. 2 is an explanatory view showing a state in which the glass roving material is wound around a vacuum valve.
The glass roving material 15 is pulled out from the bobbin 16 on which is wound, and one end of the glass roving material 15 is fixed to the lower end of the insulating cylinder of the vacuum vessel 5 via the feed roller 17 driven in the direction of the arrow, and the angle is set as described above. Wind at a constant pitch. The second layer is similarly wound at an angle in the opposite direction.

Next, the operation of the thus-configured resin-molded vacuum valve will be described. The coefficient of thermal expansion of ceramics and glass of the insulating cylinder 2 is about one digit smaller than that of general epoxy resin. Since the thermal stress is proportional to the difference in the coefficient of thermal expansion, it is preferable that the coefficient of thermal expansion be as close as possible.Therefore, conventionally, a method of increasing the content of the filler in the casting resin is adopted, As a result, the casting property is lowered, and only the expansion rate of the copper or aluminum material is reduced.

On the other hand, by impregnating the casting resin between the glass fiber layers, the expansion coefficient can be further reduced and the strength can be increased. FIG. 3 is a graph showing the characteristics of the linear expansion coefficient and the shear strength with respect to the glass fiber content when the glass fiber is cast with a casting resin in which silica particles are filled in an epoxy resin (model name: CT200) manufactured by Ciba-Geigy Corporation. It is.

By molding by impregnating the glass fiber with a casting resin, when the content of the glass fiber increases, the coefficient of thermal expansion decreases and the strength increases. In this embodiment, the fiber layers 12 and 13 of the glass fibers on the outer periphery of the insulating cylinder 2 are impregnated with a casting resin such as an epoxy resin, and the coefficient of thermal expansion of the first fiber layer 12 is reduced. Thermal stress with the surface can be reduced and strength can be increased.

Further, the second fiber layer 13 on the outer side of the first fiber layer 12 has a coarse winding pitch and a low fiber density, but the filler is not so filtered and the casting resin permeates. Therefore, a resin layer having a lower expansion coefficient than only the casting resin is formed.

In FIG. 1, the details of the corners on the outer periphery of the upper end of the vacuum vessel are omitted, but by providing the fiber layers 12 and 13, the corners of the vacuum vessel 5 are covered with the fiber layers 12 and 13. Therefore, the outer circumference of the fiber layer 13 is larger than the radius of the corner of the vacuum vessel 5 by the thickness of the fiber layers 12 and 13, and the stress of the casting resin portion in this portion is reduced.

Further, since the casting resin contains a mixture of fine particles of a few μm and a filler of silica particles, the filler of the fine particles enters also between the first and second fiber layers 12 and 13, and the outer side of the outer layer is filled with the filler. In this state, fillers having a large particle size are sequentially arranged in the fiber layer 12.
The resin layers 12, 13, and 14 whose linear expansion coefficient and strength are inclined from the outside toward the outside are formed.

Thus, a resin molded vacuum valve having excellent crack resistance can be obtained. In addition, fiber layers 12, 13
Since a predetermined gap is formed between the glass fibers, the casting resin flows at the time of casting, and can be cast by a general vacuum pressure casting method.

In the first embodiment, the first fiber layer 12
And the second fiber layer 13 were formed by winding in different ways,
The winding may be performed by sequentially changing the pitch at the time of winding from the fiber layer on the inner peripheral side and decreasing the fiber density toward the outside. In this case, the inclination of the resin layer containing the fibers becomes smoother.

As described above, in this embodiment, the winding operation of the fiber can be mechanized, and a resin-molded vacuum valve having excellent crack resistance can be obtained by a conventional vacuum casting method. Further, in this embodiment, the formation of the fiber layer with one glass roving material has been described. However, if a plurality of glass roving materials are simultaneously wound, the operation time for forming the fiber layer can be further reduced.

In the description of FIG. 2, the fiber layers 12 and 13 formed as shown in FIG. 1 are formed by winding the glass roving material 15 in place of a glass tape of 0.25 t glass tape instead of the glass roving material 15. After that, casting may be performed in the same manner as in the first embodiment to correspond to claim 3.

In the second embodiment, by employing a glass tape for forming the fiber layer, the fiber layer can be easily formed without using the winding device shown in FIG. The same operation and effect as the embodiment can be obtained.

In this embodiment, both the warp and the weft may use glass fiber glass tapes. However, by using a glass tape using a heat-shrinkable fiber such as a polyester fiber for the warp, a mold is formed. The heat-shrinkable fiber of the fiber layer wound during preheating shrinks to adhere to the insulating cylinder of the vacuum valve, and the bonding force at the interface with the insulating cylinder after casting is further strengthened. Invention.

Further, the glass tape of the first fiber layer 12
Using a 0.25 t glass tape, 0.5 t
By using coarse glass tape, the fiber layer 1
The resin molded vacuum valve which can easily change the fiber density of 2, 13 and can not only make the resin layer after the casting resin impregnation functionally inclined, but also easily have excellent crack resistance as in the first embodiment. Can be obtained.

The resin layer 1 of the first and second embodiments
The invention corresponding to claim 4 may be provided by forming the glass sleeves 2 and 13 with glass sleeves made by knitting glass fibers. In the third embodiment, as shown in FIG. 1, a glass sleeve made of glass fiber having a large diameter is sequentially covered on the outer periphery of the insulating cylinder 2 so as to have a predetermined thickness to form fiber layers 12 and 13, and then a mold is formed. And then cast with a casting resin to obtain a resin-molded vacuum valve as in FIG.

The glass sleeve is braided with the coarseness of the eyes impregnated with the casting resin, and is manufactured in advance with different diameters. It only needs to be put on sequentially until it becomes
The work process is simplified. Also in the third embodiment, the first
In addition, the same function and effect as those of the second embodiment can be obtained, and a resin-molded vacuum valve having excellent crack resistance can be obtained.

When the sleeve is braided with glass fiber, it is possible to further improve the workability if a multi-layered sleeve is manufactured in advance so that the inner side is finer and the outer side is coarser. .

Further, by forming the transverse fibers of the sleeve with polyester fibers or the like having good heat shrinkability, the sleeves shrink in the radial direction due to heating of the mold in the casting step, and adhere tightly so as to envelop the insulating cylinder. Since the adhesive force can be increased and a large sleeve is employed, the work of inserting the vacuum valve becomes easy.

FIG. 4 is a partial perspective view showing a resin-molded vacuum valve according to a fourth embodiment of the present invention, and corresponds to claim 5. In the fourth embodiment, the fiber layers 12 and 13 of the resin-molded vacuum valve shown in FIG. 1 are made of a nonwoven fabric made of glass fiber. As shown in FIG. A glass fiber cylinder 18 made of a glass non-woven fabric having an inside diameter is manufactured, the vacuum valve 1 before casting is inserted into the glass fiber cylinder 18, and thereafter, incorporated into a mold as in the first embodiment, and vacuum-pressurized. A resin molded vacuum valve is obtained by the mold.

In this case, since the fiber layer is formed of a nonwoven fabric of glass fiber having a predetermined thickness in a cylindrical shape in advance, there is no winding device or winding operation for forming the fiber layer, and no vacuum is applied. The operation is simplified because only the valve needs to be inserted.

After casting, the fibrous layer made of non-woven fabric is impregnated with the casting resin, and the same operation and effect as in the first embodiment can be obtained. Although the present embodiment has been described using a glass nonwoven fabric, a similar effect can be obtained with a glass felt cylinder made of short glass fibers.

According to a fifth embodiment of the present invention corresponding to claim 8, the glass tape and the glass sleeve used in the second and third embodiments are previously set to a low-viscosity thermosetting resin, for example, It is used in the same system as the casting resin, impregnated with an epoxy resin containing no filler, and in a semi-cured state of the B stage.

The method for forming the fiber layer on the vacuum valve and the method for casting the same are the same as in the second and third embodiments.
The glass fibers that make up the glass tape and sleeve are
Although it is composed of fine single fibers, when the viscosity is high as in the casting resin, there is a possibility that the resin is not sufficiently impregnated between the single fibers under the condition only at the time of casting.

Then, in a vacuum valve having a high rated voltage,
Since partial discharge may occur in the fine, non-impregnated portion, the defect can be prevented by impregnating the resin into the fine portion in advance. Also,
In the case of the sleeve, since the sleeve can be formed while being kept in a cylindrical shape when it is brought into the B-stage state, the subsequent insertion work becomes easy.

Depending on the rated voltage of the vacuum valve, a high-strength layer is formed by using a B-stage glass tape or sleeve containing a large amount of resin in which the resin adheres to the eyes of the glass tape or sleeve with the resin mixed with the filler. However, this part can form an insulating layer having high strength and a small coefficient of linear expansion after curing, and the casting resin on the outside thereof is of the same type as the resin of the fiber layer, so that an integrated insulating layer is formed. Therefore, a resin-molded vacuum valve having excellent clad resistance can be obtained.

Further, in this embodiment, since the glass fiber is treated with the resin, the floating and fuzzing of the glass fiber in the cutting step can be prevented, so that the working environment can be prevented from lowering. The risk of skin diseases and the like can be eliminated.

In the sixth embodiment of the present invention, hollow glass beads manufactured by Toshiba Barotini Co., Ltd. and spherical silica of fine particles of several μm are used as the filler of the epoxy casting resin.

The casting resin of the fiber layer is the same as that of the first embodiment in that the crack resistance of the resin-molded vacuum valve is the same as in the first embodiment, but by using spherical glass beads. The fluidity of the casting resin increases, and the spherical silica of the fine particles is added, so that the bearing effect (Note: small particles between large particles rotate in the casting resin as the steel ball of the bearing rotates. ) Can reduce the viscosity.

For this reason, the defoaming effect at the time of casting and the fluidity are increased. In addition, by using hollow glass beads, the specific gravity of the casting resin is reduced, and the dielectric constant is reduced. This allows
Since the weight of the resin-molded vacuum valve can be reduced and the dielectric constant can be reduced, the potential gradient of the surface of the resin that comes into contact with air can be reduced.

According to a seventh embodiment of the present invention, a fiber layer is formed on a vacuum valve according to the above-described embodiment, and then a temperature of 120 ° C.
Assemble into mold heated to ~ 140 ° C and clamp mold.
Thereafter, the interior of the mold is evacuated and the casting resin is injected from below while pressurizing while maintaining the degree of vacuum constant.
When the casting resin in the mold is gelled under pressure and reaches a certain strength, pressurization is stopped, the clamp of the mold is released, the mold is released, and it is completely cured in the secondary curing furnace, and integrated. To obtain a resin molded vacuum valve.

CY225 / HY925 for epoxy resin and curing agent
When the mold temperature was set to 130 ° C. with a casting resin mixed with a silica filler using (trade name of Ciba Geigy), the mold could be released 30 minutes after the start of the injection of the casting resin.

In the present method, since the casting resin is pressurized in a state of being evacuated, the pressure difference increases, and the permeation into the fiber layer becomes easy. Furthermore, since it gels under pressure,
The occurrence of sink marks and voids can be prevented.

In addition, since the resin is gelled from a portion distant from the injection port, the temperature of the mold can be increased, the time required for releasing the mold can be reduced, and the resin injected into the mold can be raised in a short time. Since the viscosity is reduced by heating, it is easy to penetrate the fiber layer. This makes it possible to obtain a good resin molding vacuum valve with a short casting operation time and few defects.

The eighth embodiment of the present invention is the same as the first to sixth embodiments, except that the resin is cast with a casting resin using fine and coarse silica fillers as the filler, and then the primary curing furnace is used. A DC voltage of 200 V to 300 V is applied between the mold and the conductor shaft of the vacuum valve, and the mold is released after curing, and then subjected to secondary curing to obtain an integrated resin molded vacuum valve.

In this method, when a casting resin is in a liquid state, a DC voltage is applied to charge the filler in the casting resin, and the filler of small fine particles having a small particle diameter is electrophoresed. It moves to the outer surface side of the insulating cylinder due to the phenomenon, and is hardened in a state where the adhesive strength is increased by Coulomb force, and the adhesive force on the surface of the insulating cylinder is further strengthened.

Further, the distribution of the filler in the entire resin layer can be suppressed, and the function of the resin layer including the resin layer can be graded. FIG. 5 is a longitudinal sectional view showing a ninth embodiment of the vacuum valve of the present invention, and is a view corresponding to FIG.

In this embodiment, a fiber layer is formed on a vacuum valve by the method of forming a fiber layer according to any one of the first to fifth embodiments, and the three vacuum valves formed with the fiber layer are connected to a mold. And these vacuum valves are cast integrally. In FIG. 5, as in FIG. 1, fiber layers 12, 13 are formed on the respective vacuum valves 1A, 1B, 1C, and a resin layer 19 is formed by integrally casting the whole.

The effect of each valve on crack resistance is the same as that of the previous embodiments. However, by integrally casting three vacuum valves, the resin layer 19 solid-insulates the phase between the vacuum valves. Therefore, the insulation distance between the phases can be shortened, the width of the circuit breaker can be reduced, and the power receiving and distribution equipment in which the circuit breaker is incorporated can be downsized.

Furthermore, since three pieces are cast at the same time, the productivity of the casting manufacturing process can be improved. In addition, since the three valves are integrated with the resin layer 19, the time required for assembling the circuit breaker or switch incorporating the vacuum valve can be reduced, and the adjustment work can be omitted.

[0066]

As described above, according to the first aspect of the present invention, the inner fiber layer formed on the outer periphery of the insulating cylinder accommodating the fixed contact and the movable contact, and the outer fiber layer formed on the outer periphery of the inner fiber layer. An outer fiber layer that forms a larger gap between the fibers of the inner fiber layer than between the fibers, and an insulating layer that is impregnated in the inner fiber layer and the outer fiber layer, is cured, and adheres to the outer periphery of the insulating cylinder. Then, on the insulating cylinder side inside the insulating layer,
Forming an insulating layer with high fiber density and low coefficient of thermal expansion,
An insulating layer with a low fiber density and a gradually increasing thermal expansion coefficient is formed on the outer peripheral side of the insulating layer, so it has excellent crack resistance against temperature changes during energization and stoppage, and can be miniaturized. You can get a valve.

According to the second aspect of the present invention, the inner fiber layer and the outer fiber layer are formed by winding a glass roving material. According to the invention corresponding to claim 4, by forming the fiber layer with a glass tape, according to the invention corresponding to claim 5, by forming the inner fiber layer and the outer fiber layer with a plurality of glass sleeves, By forming the inner fiber layer and the outer fiber layer with a cylindrical glass nonwoven fabric or glass felt, an insulating layer having a high fiber density and a low coefficient of thermal expansion is formed on the insulating cylinder side inside the insulating layer. The outer layer of the insulating layer is formed with an insulating layer with a low fiber density and a gradually increasing thermal expansion coefficient, so it is excellent in crack resistance against temperature change between energization and shutdown, and can be miniaturized. To get a vacuum valve Kill.

According to the invention corresponding to claim 6, since polyester fiber is employed as the warp of the glass tape, the fiber is shrunk by heat at the time of molding the resin, and the fiber is brought into close contact with the outer periphery of the insulating cylinder. It is possible to obtain a resin-molded vacuum valve that is excellent in crack resistance against temperature changes during energization and stoppage and that can be downsized.

According to the invention corresponding to claim 8, by using the epoxy resin impregnated in the glass tape, the glass sleeve or the glass non-woven fabric in the B stage state, the resin in the low viscosity state can be sufficiently interposed between the fibers. After the infiltration, the stage is brought into the B-stage state, so that a resin-molded vacuum valve that is excellent in crack resistance against temperature changes during energization and stoppage and that can be miniaturized can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of a resin-molded vacuum valve of the present invention.

FIG. 2 is an explanatory view showing a first embodiment of the resin-molded vacuum valve of the present invention.

FIG. 3 is a graph showing the operation of the resin-molded vacuum valve of the present invention.

FIG. 4 is a partial perspective view showing a fourth embodiment of the resin-molded vacuum valve of the present invention.

FIG. 5 is a longitudinal sectional view showing a ninth embodiment of the resin-molded vacuum valve of the present invention.

FIG. 6 is a longitudinal sectional view showing an example of a conventional vacuum valve.

FIG. 7 is a longitudinal sectional view showing an example of a conventional resin-molded vacuum valve.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vacuum valve, 2 ... Insulated cylinder, 3 ... Fixed side end plate, 4 ...
Movable end plate, 5: vacuum vessel, 6: fixed-side conductor, 7: movable-side conductor, 8: bellows, 9: contact, 10: buffer layer, 11: insulating jacket, 12: first fiber layer, 13 ... second fiber layer, 14 ... cast resin layer, 15 ... glass roving material, 16 ... bobbin, 17 ...
Feed roller, 19 ... resin layer.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Susumu Kinoshita 1 Toshiba-cho, Fuchu-shi, Tokyo, Japan Inside the Toshiba Fuchu Plant, Inc. 72) Inventor Hiroki Sekiya 1 Toshiba-cho, Fuchu-shi, Tokyo F-term in the Fuchu factory of Toshiba Corporation (reference) 5G026 EA04 EB09

Claims (8)

[Claims] 1. An inner fiber layer formed on the outer periphery of an insulating cylinder accommodating a fixed contact and a movable contact, and a gap formed on the outer periphery of the inner fiber layer and being larger than the fibers of the inner fiber layer. A resin-molded vacuum valve comprising: an outer fiber layer formed between fibers; and an insulating layer which is impregnated into the inner fiber layer and the outer fiber layer, is cured, and adheres to the outer periphery of the insulating cylinder. 2. The method according to claim 1, wherein the inner fiber layer and the outer fiber layer are formed by winding a glass roving material.
The resin-molded vacuum valve according to the above. 3. The resin-molded vacuum valve according to claim 1, wherein the inner fiber layer and the outer fiber layer are formed of a glass tape. 4. The resin-molded vacuum valve according to claim 1, wherein the inner fiber layer and the outer fiber layer are formed by a plurality of glass sleeves. 5. The resin-molded vacuum valve according to claim 1, wherein the inner fiber layer and the outer fiber layer are formed of a cylindrical glass nonwoven fabric or glass felt. 6. The resin-molded vacuum valve according to claim 3, wherein a polyester fiber is used as a warp of the glass tape. 7. The insulating layer is formed by cast molding of an epoxy resin mixed with 70 to 75% by weight of a particulate fused silica filler and 2 to 5% by weight of spherical silica fine particles. The resin-molded vacuum valve according to any one of claims 1 to 6. 8. The resin-molding vacuum according to claim 3, wherein the impregnated epoxy resin is used in the glass tape, the glass sleeve, or the glass nonwoven fabric in a B-stage state. valve.