WO2023176514A1

WO2023176514A1 - Vacuum capacitor

Info

Publication number: WO2023176514A1
Application number: PCT/JP2023/008081
Authority: WO
Inventors: 良行谷水
Original assignee: 株式会社明電舎
Priority date: 2022-03-17
Filing date: 2023-03-03
Publication date: 2023-09-21
Also published as: JP7327555B1; JP2023136974A

Abstract

This vacuum capacitor comprises, as major elements in a vacuum container (1A): a fixed electrode (7); a movable electrode support portion (91) that is disposed opposite the fixed electrode (7) and is movable in an axial direction (Y); a movable electrode (8) that is provided on the movable electrode support portion (91) opposite the fixed electrode (7), and that forms a capacitance between the movable electrode (8) and the fixed electrode (7); a tubular bellows (14) that is supported at one end on a movable-side conductor (6) side of the movable electrode support portion (91) and at the other end on the movable-side conductor (6); and a heat-dissipating portion (17). The heat-dissipating portion (17) has a tubular shape extending in the axial direction (Y) between a tubular body (1a) and the bellows (14) in a vacuum chamber (15), and is supported closer to the outer periphery than the bellows (14) on the movable electrode support portion (91).

Description

vacuum capacitor

The present invention relates to a vacuum capacitor, and relates to vacuum capacitor technology that can be applied to impedance adjustment in high-frequency equipment such as a high-frequency power supply for semiconductor equipment and a high-power oscillation circuit.

Conventionally, various vacuum capacitors (for example, Patent Documents 1 to 3) have been used for impedance adjustment in high frequency equipment such as high frequency power supplies of general semiconductor equipment and high power transmission circuits.

Vacuum capacitor B shown in FIG. 2 is a schematic explanatory diagram showing a general example (variable vacuum capacitor). In the vacuum capacitor B of FIG. 2, both ends of a cylindrical body 1b, at least a portion of which has an insulating property, are closed by a fixed conductor 5 and a movable conductor 6 to form a vacuum vessel 1B.

In the case of the cylindrical body 1b in FIG. 2, a metal material (copper, etc.) is applied to both ends (fixed conductor 5 side, movable conductor 6 side) of an insulating tube 2 made of an insulating material (ceramic material, etc.). The flange pipes 3 and 4 used are arranged coaxially in series.

The reference numeral 6a indicates a cooling part provided outside the vacuum vessel 1B in the movable conductor 6. The cooling unit 6a has a cooling water hole 6b through which cooling water can flow, and the vacuum condenser B can be cooled by flowing cooling water into the cooling water hole 6b as necessary. It is configured as follows.

The reference numeral 7 indicates a fixed electrode that is constructed by concentrically spaced a plurality of substantially cylindrical electrode members having different inner diameters and spaced apart at regular intervals, and is provided inside the vacuum vessel 1B of the fixed conductor. Reference numeral 9 indicates a movable electrode support part that supports a movable electrode 8 (to be described later), which is disposed facing the fixed side conductor 5, and which is connected to the vacuum vessel 1B in the axial direction Y ( It is configured to be movable in the direction of both ends of the cylindrical body 1b.

Like the fixed electrode 7, the movable electrode 8 is composed of a plurality of substantially cylindrical electrode members having different inner diameters arranged concentrically at regular intervals. Each electrode member of this movable electrode 8 is provided with a movable electrode support portion so that it can be inserted into and removed from the fixed electrode 7 without contacting the fixed electrode 7 (inserted into and taken out between the electrode members of the fixed electrode 7 and crossed each other). It is provided facing the fixed electrode 7 on the side of the fixed side conductor 5 of 9, so that a capacitance can be formed between the fixed electrode 7 and the fixed electrode 7. In the case of the movable electrode support part 9 shown in FIG. 2, it has a flat plate shape extending in the radial direction of the vacuum container 1B.

Reference numeral 10 extends in the axial direction Y from the back side of the movable electrode support part 9 (the side of the movable conductor 6 where the fixed electrode 7 is not provided) (in FIG. 2, the movable conductor 6 side of the vacuum vessel 1B is projected). This figure shows an extended movable rod (a hollow movable rod in FIG. 2).

In the case of the movable rod 10 shown in FIG. 2, the movable rod 10 is slidable (the movable rod 10 is The outer peripheral surface of the bearing member 11 is slidably supported by the bearing member 11 (slidably in the axial direction Y).

Reference numeral 12 indicates a rod (hereinafter referred to as an insulation operation rod) that moves the movable rod 10 while being guided in the axial direction Y by the bearing member 11, and adjusts the capacitance of the vacuum capacitor B to perform insulation operation. It is something. In the case of the insulated operating rod 12 shown in FIG. The male screw portion 12b is screwed into the female screw portion 10a formed on the inner wall of one end of the movable rod 10, and the other end (in FIG. 2, the side where the head 12a made of an insulating material is formed, for example) ) is configured so that a drive source (such as a motor) not shown in the figure can be connected.

In addition, the insulating operation rod 12 is connected to a support (in FIG. 2, a screw receiving part) provided in the vacuum vessel 1B (in FIG. 2, it is fixedly installed so as to protrude from the movable conductor 6 and cover the bearing member 11). 13a and a thrust bearing 13b for reducing rotational torque (hereinafter referred to as an operating rod support) 13, it is rotatably supported.

Reference numeral 14 indicates a cylindrical (for example, bellows-shaped) bellows made of soft metal as part of the current conduction path of the vacuum capacitor B. This bellows 14 is designed to airtight (make a vacuum state possible) a space 15 (hereinafter referred to as a vacuum chamber) surrounded by the outer peripheral side of the bellows 14 in the vacuum container 1B, that is, the fixed electrode 7, the movable electrode 8, and the bellows 14. The movable electrode 8, the movable electrode support part 9, and the movable rod 10 are configured to be movable in the axial direction Y while being kept airtight. In the case of the bellows 14 in FIG. 2, one edge of the bellows 14 is joined to the inner wall of the movable conductor 6, and the other edge of the bellows 14 is joined to the movable conductor 6 of the movable electrode support portion 9. A space 16 at atmospheric pressure (hereinafter referred to as an atmospheric chamber) is formed on the inner peripheral side of the bellows 14 (on the movable rod 10 side of the bellows 14) in the vacuum container 1B.

Note that various shapes of the bellows 14 are known, such as a structure in which the other end side edge of the bellows 14 is joined to the surface of the movable rod 10, and a structure in which the bellows 14 itself is doubled ( For example, there is a structure that combines a stainless steel bellows and a copper bellows.

In the vacuum capacitor B configured as shown above, by rotating the insulation operation rod 12 by a drive source not shown, the movable rod 10 moves in the axial direction Y with the rotation, and the fixed electrode 7 The intersection area between the movable electrode 8 and the movable electrode 8 changes. As a result, when voltages of different polarities are applied to the

electrodes

7 and 8, the value of the capacitance generated between the

electrodes

7 and 8 is continuously adjusted, and the impedance is adjusted. has been done.

When such a vacuum capacitor B is used, a high frequency current for a high frequency device will flow through a current path as shown below. That is, the high-frequency current first flows through the fixed conductor 5 and the fixed electrode 7, then flows to the movable electrode 8 via the capacitance between the

electrodes

7 and 8, and then from the movable electrode 8 to the movable electrode. It flows to the movable conductor 6 via the support portion 9, bellows 14, and movable rod 10.

In recent years, the load on high-frequency equipment has gradually increased, and the high-frequency current flowing through the high-frequency equipment has increased. For this reason, it is desired that the vacuum capacitor B used in the high frequency equipment has a high ability to conduct high frequency current.

Japanese Patent Application Publication No. 10-141455 Patent No. 4692211 Japanese Patent Application Publication No. 2005-175026

Among the components of vacuum capacitor B, the components that serve as conduction paths for high-frequency currents (hereinafter simply referred to as conduction path components as appropriate) tend to generate heat and reach high temperatures when the high-frequency currents flow. It is possible that this could happen.

Among the current-carrying path components, the fixed conductor 5, movable conductor 6, fixed electrode 7, movable rod 10, etc. are exposed to or near the outer circumference of the vacuum container 1B, or exposed to the atmospheric chamber 16. Even if heat is generated by the high-frequency current, it is considered that the heat is easily radiated by conduction to the outer circumferential side of the vacuum container 1B.

However, among the current conduction path components, the movable electrode 8, the movable electrode support portion 9, and the bellows 14 (hereinafter, these will be collectively referred to as three elements) are exposed to the vacuum chamber 15 where convective heat radiation is difficult to occur, and Because it is located away from the outer circumference of the vacuum vessel 1B, heat generated by high-frequency current is likely to be accumulated (it is difficult to conduct heat radiate to the outer circumference of the vacuum vessel 1B), and it is thought that it is likely to reach a higher temperature state. It will be done.

Furthermore, when a voltage is applied to the

electrodes

7 and 8 to cause a high frequency current to flow, a high electric field state may occur, especially in a minute gap such as between the

electrodes

7 and 8. The three elements under such a high electric field state tend to emit thermoelectrons when the temperature becomes high as described above. When thermoelectrons are emitted as described above, it becomes difficult to maintain vacuum insulation, and the desired function of the vacuum capacitor B cannot be achieved.

Therefore, in vacuum capacitor B, the ability to conduct high-frequency current has been limited in order to prevent the current-carrying path components from reaching high temperatures.

The present invention has been made in view of the above-mentioned technical problems, and can contribute to suppressing the high temperature of the current-carrying path components (three elements) and making it easier to demonstrate the ability to carry high-frequency current. Our goal is to provide vacuum capacitors with excellent quality.

The electrical equipment storage board according to the present invention is a creation that can solve the above-mentioned problems, and one aspect thereof is that both ends of a cylindrical body, at least a part of which has an insulating property, are closed by a fixed conductor and a movable conductor. a formed vacuum container, a fixed electrode provided on the fixed conductor side in the vacuum container, and a movable electrode support located opposite to the fixed electrode in the vacuum container and movable toward both ends of the cylindrical body. a movable electrode that is provided facing the fixed electrode on the fixed conductor side of the movable electrode support part and forms a capacitance between the movable electrode and the fixed electrode; and a cylindrical bellows whose other end is supported by the movable conductor.

The inside of the vacuum container is divided by the bellows into a vacuum chamber on the outer circumferential side of the bellows and an atmospheric chamber on the inner circumferential side of the bellows. The heat dissipation part extending in the direction of both ends between the movable electrode support parts is supported on the outer peripheral side of the bellows in the movable electrode support part.

Furthermore, the outer circumferential surface of the heat dissipation section may be characterized in that a heat dissipation section uneven surface formed in an uneven shape is formed.

Furthermore, the outer circumferential surface of the heat dissipation part may be coated with a thermally conductive material.

Further, the cylindrical body includes an insulating tube made of an insulating material, and a pair of flange tubes made of a metal material and coaxially connected in the direction of both ends of the insulating tube. Of the pair of flange pipes, the flange pipe facing the heat dissipation part in the radial direction of the cylindrical body has an uneven shape formed on at least one of the outer peripheral surface and the inner peripheral surface of the flange pipe. The flange pipe may be characterized in that a concavo-convex surface is formed.

Furthermore, in the flange pipe facing the heat radiating section, at least one of the outer peripheral surface and the inner peripheral surface of the flange pipe may be coated with a thermally conductive material.

As described above, according to the present invention, it is possible to suppress the current-carrying path constituent elements (three elements) from becoming high temperature and contribute to making it easier to exhibit the high-frequency current carrying ability.

FIG. 2 is a schematic explanatory diagram (longitudinal cross-sectional view in the axial direction Y) showing an example of a vacuum capacitor in the present embodiment. A schematic explanatory diagram (a vertical cross-sectional view in the axial direction Y) of a general vacuum capacitor B.

In the vacuum capacitor according to the embodiment of the present invention, three elements (hereinafter, the three elements of vacuum capacitor B in FIG. 2 will be referred to as the conventional three elements) are simply placed in a vacuum chamber, such as the vacuum capacitor B shown in FIG. This is completely different from the configuration that you are exposed to.

That is, in the vacuum capacitor of this embodiment, in the vacuum chamber of the vacuum container, the axial direction of the vacuum container (in FIG. 1, both ends of the cylindrical body 1a (axial direction Y)) is formed between the vacuum container and the bellows. The device is equipped with a heat dissipation section extending to. This heat dissipation part is supported on the outer peripheral side (that is, on the vacuum chamber side) of the movable electrode and the bellows in the movable electrode support part that supports the movable electrode and the bellows.

Now, focusing on the vacuum capacitor B in FIG. 2, it does not have a heat dissipation part as described above, and in the conventional three elements, it is simply exposed to the vacuum chamber 15 where convective heat dissipation is difficult to occur, and the vacuum capacitor B is It will be located away from the outer circumferential side. Therefore, it can be seen that the conventional three elements tend to accumulate heat when generated by high frequency current.

For example, heat generated by the movable electrode 8 and the movable electrode support part 9 of the three conventional elements can be conductively radiated to the outer peripheral side of the vacuum chamber 1B via the movable rod 10 and the like. However, the movable rod 10 is likely to be designed with a small cross-sectional area due to limitations due to the diameter of the bellows 14, and the heat conduction resistance of the gap between the movable rod 10 and the bearing member 11 tends to be high. For this reason, conduction heat radiation through the movable rod 10 and the like may be limited.

In particular, when the movable electrode 8 is composed of a plurality of substantially cylindrical electrode members having different inner diameters as shown in FIG. It is thought that it is easy to become hot (high temperature).

Furthermore, among the three conventional elements, the heat generated by the bellows 14 can be conductively radiated to the outer peripheral side of the vacuum vessel 1B via the movable conductor 6 and the like. However, since many of the bellows 14 are designed to have a small cross-sectional area, even if the movable conductor 6 is cooled, conduction heat radiation through the movable conductor 6 etc. may be limited. .

For example, when the three conventional elements are made of copper, the emissivity of the copper is relatively low (approximately 0.02), so even if there is a temperature difference between the three conventional elements and the surroundings, It is thought that the radiant heat dissipation of the three conventional elements will be relatively small. That is, in the case where the three conventional elements are made of copper, the amount of heat released relative to the amount of heat generated is small, and most of the heat generated is stored, making it easy to reach a high temperature.

In the case of the conventional three elements that have reached such a high temperature, the resistance increases due to the temperature coefficient of the electrical resistance of the material, which may lead to a further increase in heat generation and temperature rise. For example, if the three conventional elements are made of copper and the temperature is 300°C, the electrical resistance of the copper is approximately 1.8 times that at room temperature, so the calorific value of the three conventional elements will also be There is a possibility that it will increase by 1.8 times.

Then, by applying a voltage to the

electrodes

7 and 8 of the vacuum capacitor B and flowing a high frequency current, the three elements are conventionally under a high electric field state and furthermore, when the temperature becomes high as described above, they tend to emit thermoelectrons. As a result, it becomes difficult to maintain vacuum insulation, and the desired function of the vacuum capacitor B cannot be achieved. Therefore, in the vacuum capacitor B, the ability to conduct high-frequency current is limited, for example, by a limit value based on the lower of the temperature rise limit on the outer peripheral side of the vacuum container 1B and the thermionic emission temperature limit. I had left it behind.

In addition, in the vacuum capacitor B, by increasing the diameter of the bellows 14 or making the bellows 14 itself have a double structure, there is a possibility that the amount of heat generated by the vacuum capacitor B can be reduced and the ability to conduct high-frequency current can be improved. However, this may lead to an increase in the size and cost of the vacuum capacitor B.

On the other hand, according to the vacuum capacitor of this embodiment, since the heat dissipation section is supported by the movable electrode support section, for example, when three elements generate heat, the heat is easily radiated through the heat dissipation section. It becomes possible to suppress the heat storage amount of the three elements and reduce the temperature. It also becomes easier to suppress the emission of thermoelectrons from the three elements under high electric field conditions. This makes it easier to demonstrate the ability to conduct high-frequency current.

The vacuum capacitor of this embodiment may have a configuration in which the heat dissipation part is supported on the outer peripheral side of the bellows in the movable electrode support part as described above, and various design changes are possible. That is, it is possible to modify the design by appropriately applying common technical knowledge in various fields (for example, vacuum capacitor field, surface treatment field, coating field, etc.) and referring to prior art documents as necessary.

Note that in the following embodiments, detailed explanations will be omitted as appropriate, for example, by quoting the same reference numerals for the same contents as in FIG. 2.

≪Example≫
FIG. 1 illustrates the configuration of a vacuum capacitor A according to this embodiment. In this vacuum capacitor A, a vacuum vessel 1A is constructed by closing both ends of a cylindrical body 1a, at least a portion of which has an insulating property, with a fixed conductor 5 and a movable conductor 6. Inside this vacuum container 1A, there is a fixed electrode 7 provided on the fixed side conductor 5 side in the vacuum container 1A, and a fixed electrode 7 disposed facing the fixed electrode 7 in the vacuum container 1A in the axial direction Y (cylindrical body). A capacitance is formed between a movable electrode support part 91 that is movable in the direction of both ends of the movable electrode support part 91 and the fixed electrode 7 that is provided opposite to the fixed electrode 7 on the fixed side conductor 5 side of the movable electrode support part 91. The main elements are a movable electrode 8, a cylindrical bellows 14 whose one end is supported on the movable conductor 6 side of the movable electrode support part 91 and the other end supported by the movable conductor 6, and a heat dissipation part 17. It is provided as

The heat radiation part 17 has a cylindrical shape extending in the axial direction Y between the cylindrical body 1a and the bellows 14 in the vacuum chamber 15, and is supported on the outer peripheral side of the movable electrode support part 91 relative to the bellows 14. The configuration is as follows.

The materials used (metal materials, insulating materials, thermally conductive materials, etc.) and shapes of each component of the vacuum capacitor A in Figure 1 as shown above vary depending on the purpose of use of the vacuum capacitor A. Therefore, it is possible to apply various aspects as appropriate, and examples thereof include those shown below.

<An example of the cylindrical body 1a>
The cylindrical body 1a shown in FIG. 1 has a metal material (for example, copper, The flange pipe 3 (fixed side conductor 5 side) and 41 (movable side conductor 6 side) made of flange pipes 3 (on the fixed side conductor 5 side) and 41 (on the movable side conductor 6 side) are coaxially arranged in series.

Further, among the flange pipes 3 and 41, a flange pipe that overlaps with the heat radiation part 17 in the axial direction Y (that is, faces the heat radiation part 17 in the radial direction of the cylindrical body 1a (direction that intersects the axial direction Y)) 41, a flange tube uneven surface is formed on the inner circumferential surface and outer circumferential surface of the flange tube 41, respectively, and is formed into an uneven shape by

grooves

41a and 41b, respectively.

In the case of the uneven surface of the flange pipe shown in FIG. However, it is not limited to this. That is, any material may be used as long as the inner circumferential surface and outer circumferential surface of the flange pipe 41 are formed into an uneven shape so as to increase the surface area.

For example, the cross-sectional shape of the inner wall surfaces of the

slots

41a and 41b may be V-shaped instead of U-shaped as shown in FIG. Further, instead of providing the

slots

41a and 41b on the inner and outer circumferential surfaces of the flange pipe 41, the uneven surfaces may be formed by roughening them.

Furthermore, the uneven surface of the flange tube may be formed only on at least one of the inner circumferential surface and the outer circumferential surface of the flange tube 41. Furthermore, the inner peripheral surface and outer peripheral surface of the flange pipe 41 may be coated with a thermally conductive material, which will be described later.

Note that when the flange pipe 3 overlaps the heat radiating part 17 in the axial direction Y (for example, the heat radiating part 17 shown in FIG. At least one of the inner circumferential surface and outer circumferential surface of the flange tube 3 may be formed with an uneven surface or may be coated with a thermally conductive material to be described later.

<Example of fixed electrode 7, movable electrode 8, movable electrode support part 91>
Each of the fixed electrode 7 and the movable electrode 8 shown in FIG. 1 is composed of a plurality of substantially cylindrical electrode members having different inner diameters spaced concentrically at regular intervals. The movable electrode support part 91 shown in FIG. 1 has a flat plate shape extending in the radial direction of the vacuum container 1A, similar to the movable electrode support part 9 shown in FIG. Each electrode member of the movable electrode 8 is supported on the side conductor 5 side.

Each electrode member of the movable electrode 8 supported by the movable electrode support part 91 is inserted into the fixed electrode 7 in a non-contact state by the movement of the movable electrode support part 91 in the axial direction Y. It is configured to be able to move in and out (inserted into and out of each electrode member of the fixed electrode 7 and cross each other), and to form a capacitance with the fixed electrode 7.

<Heat radiation part 17>
The heat dissipation part 17 shown in FIG. 1 is formed into a cylindrical shape using a metal material (for example, copper, SUS, etc.), and is provided with a step part 17b at the center of the inner peripheral surface. The portion 17b is configured to be engaged with and supported by the outer peripheral edge of the movable electrode support portion 91.

Further, on the outer circumferential surface of the heat radiating portion 17, a heat radiating portion uneven surface formed into an uneven shape by the slots 17a is formed. In the case of the uneven surface of the heat dissipation part shown in FIG. 1, a plurality of ring-shaped slots 17a extending in the circumferential direction of the heat dissipation part 17 are provided at predetermined intervals in the axial direction Y. However, it is not limited to this. That is, any material may be used as long as it is formed into an uneven shape so as to increase the surface area of the outer peripheral surface of the heat dissipating portion 17.

For example, the cross-sectional shape of the inner wall surface of the slot 17a may be V-shaped in addition to the U-shape shown in FIG. Further, instead of providing the slots 17a on each of the outer circumferential surfaces of the heat dissipating section 17, the heat dissipating section uneven surface may be formed by roughening the surface. Furthermore, the outer circumferential surface of the heat dissipation section 17 may be coated with a thermally conductive material, which will be described later.

<Example of coating of thermally conductive material>
The inner and outer circumferential surfaces of the flange pipes 3 and 41 and the outer circumferential surface of the heat radiating section 17 may be coated with a thermally conductive material, respectively. This improves the amount of heat radiation on the outer peripheral surface of the heat radiating part 17 and the outer peripheral surface of the flange pipes 3, 41, and improves the heat absorption rate of the inner peripheral surface of the flange pipes 3, 41 (the heat absorption rate such as radiant heat from the heat radiating part 17). This makes it possible to improve the

Various embodiments can be applied in coating the thermally conductive material. Examples of this include coatings such as chrome plating, black chrome plating, matte nickel plating, and ceramic coatings such as SiZrO _{4 ,} Mn ₂ O ₃ , Fe ₂ O ₃ , and CoO. Furthermore, in the case of the outer circumferential surfaces of the flange pipes 3 and 41, coating with dark paint may also be used.

As a specific example, coating with chrome plating has a relatively high emissivity of about 0.9 (about 45 times the emissivity of copper), making it possible to sufficiently improve the amount of heat radiation and heat absorption rate. It is.

<Example of operation of vacuum capacitor A>
In the vacuum capacitor A, by rotating the operating rod 12 by a drive source (not shown), the movable rod 10 moves in the axial direction Y of the vacuum container 1A, and the intersection area between the fixed electrode 7 and the movable electrode 8 changes. , the capacitance is adjusted to adjust the impedance.

Furthermore, when a voltage is applied to the

electrodes

7 and 8 of the vacuum capacitor A to cause a high frequency current to flow, the high frequency current will flow in the current path as shown below. That is, the high-frequency current first flows through the fixed conductor 5 and the fixed electrode 7, then flows to the movable electrode 8 via the capacitance between the

electrodes

7 and 8, and then from the movable electrode 8 to the movable electrode. It flows to the movable conductor 6 via the support portion 91, the bellows 14, and the movable rod 10.

Among the heat generation that may occur in the current-carrying path components of the vacuum capacitor A when a high-frequency current is passed in this way, for example, heat generation in the fixed conductor 5 and the fixed electrode 7 is caused by Heat is radiated to the outer peripheral side of the vacuum container 1A via the side conductor 5 and the like.

The heat generated by the movable conductor 6, the movable rod 10, etc. is radiated to the outer circumferential side of the vacuum vessel 1A via the atmospheric chamber 16 and the cooling water flowing into the cooling water hole 6b of the cooling section 6a.

The heat generated by the three elements (movable electrode 8, movable electrode support part 91, and bellows 14) of the vacuum capacitor A can be radiated through the heat radiation part 17, and the amount of heat stored in the three elements is suppressed. Particularly, when the heat dissipation part 17 is formed with a heat dissipation part uneven surface or is coated with a thermally conductive material, it becomes easier to dissipate heat, and the amount of heat stored in the three elements becomes easier to be suppressed.

This makes it possible to sufficiently reduce the temperature in the three elements of vacuum capacitor A. Furthermore, in the three elements whose temperature has been sufficiently reduced as described above, the resistance will be reduced by the temperature coefficient of electrical resistance, and there is a possibility that the temperature of the three elements can be further reduced.

The radiant heat from the heat radiating part 17 is absorbed by the cylindrical body 1a through the inner circumferential surface of the cylindrical body 1a, which overlaps the heat radiating part 17 in the axial direction Y, for example, and is absorbed by the cylindrical body 1a on the outer circumferential side of the vacuum container 1A. Heat will be dissipated. In particular, of the flange pipes 3 and 41 of the cylindrical body 1a, the one that overlaps the heat radiation part 17 in the axial direction Y (the flange pipe 41 in FIG. 1) has a flange pipe uneven surface formed on its inner peripheral surface. If the flange pipe is coated with a thermally conductive material or is coated with a thermally conductive material, it becomes easier to absorb the radiant heat from the heat dissipating part 17. Furthermore, if the flange pipe has an uneven surface on its outer peripheral surface or is coated with a thermally conductive material, In this case, the absorbed radiant heat is easily radiated to the outer circumferential side of the vacuum container 1A.

Therefore, according to the vacuum capacitor A according to this embodiment, the amount of heat stored in the three elements is suppressed, the temperature is reduced, and the emission of thermoelectrons from the three elements under a high electric field condition is also easily suppressed. This makes it easier to demonstrate the ability to conduct high-frequency current.

Although only the specific examples described in the present invention have been described in detail above, it is obvious to those skilled in the art that various changes can be made within the scope of the technical idea of the present invention. It is a matter of course that such changes and the like fall within the scope of the claims.

For example, the bellows 14 of the vacuum capacitor A may have a variety of shapes. For example, the bellows 14 itself may have a double structure (for example, a structure in which a stainless steel bellows and a copper bellows are combined). structure).

Claims

A vacuum vessel formed by closing both ends of a cylindrical body, at least a portion of which has insulating properties, with a fixed conductor and a movable conductor;
A fixed electrode provided on the fixed conductor side in the vacuum container,
a movable electrode support part located opposite the fixed electrode in the vacuum container and movable in the direction of both ends of the cylindrical body;
a movable electrode that is provided opposite to the fixed electrode on the fixed conductor side of the movable electrode support part and forms a capacitance between the movable electrode and the fixed electrode;
a cylindrical bellows with one end supported on the movable conductor side of the movable electrode support part and the other end supported on the movable conductor;
Equipped with
The inside of the vacuum container is divided by a bellows into a vacuum chamber on the outer circumferential side of the bellows and an atmospheric chamber on the inner circumferential side of the bellows,
A vacuum capacitor characterized in that a heat dissipation part extending in the direction of both ends between the cylindrical body and the bellows in the vacuum chamber is supported on the outer peripheral side of the bellows in the movable electrode support part.
2. The vacuum capacitor according to claim 1, wherein an uneven surface of the heat dissipation section is formed on the outer peripheral surface of the heat dissipation section.
3. The vacuum capacitor according to claim 1, wherein the outer circumferential surface of the heat dissipation part is coated with a thermally conductive material.
The cylindrical body is
an insulating tube made of an insulating material;
a pair of flange tubes made of a metal material and coaxially connected in the direction of both ends of the insulating tube;
It has
Of the pair of flange pipes, the flange pipe facing the heat radiation part in the radial direction of the cylindrical body has a flange formed in an uneven shape on at least one of the outer peripheral surface and the inner peripheral surface of the flange pipe. The vacuum capacitor according to any one of claims 1 to 3, characterized in that the tube has an uneven surface.
5. The vacuum capacitor according to claim 4, wherein at least one of an outer circumferential surface and an inner circumferential surface of the flange tube facing the heat radiation part is coated with a thermally conductive material. .