Variable vacuum capacitor with fast switching and large capacitance

Abstract

This invention discloses a variable vacuum capacitor capable of rapidly switching large capacitance values, comprising a first capacitor, a second capacitor, an intermediate electrode disk, and a driving device. The first capacitor includes a first electrode group A and a first electrode group C, and the second capacitor includes a second electrode group B and a second electrode group C. The intermediate electrode disk is disposed between the first and second capacitors, and the first and second electrode groups C are respectively fixed on opposite sides of the intermediate electrode disk. The second electrode group B is electrically connected to a moving disk. Conductive protrusions are provided on the intermediate electrode disk and / or the moving disk. The driving device drives the moving disk to reciprocate relative to the intermediate electrode disk, thereby switching the second capacitor between an open-circuit state and a short-circuit state. In the short-circuit state, the moving disk and the intermediate electrode disk are connected and conductive through the conductive protrusions. This invention achieves rapid switching of large capacitance values ​​by changing the short-circuit and open-circuit states of the second capacitor.

Description

Technical Field

[0001] This invention relates to the field of vacuum capacitor technology, and in particular to a variable vacuum capacitor capable of rapidly switching large capacitance values. Background Technology

[0002] Vacuum capacitors, a type of special capacitor with a ceramic insulating shell, a vacuum dielectric, and high-conductivity oxygen-free copper electrodes, occupy an irreplaceable position in high-frequency, high-voltage applications due to their core advantages of high voltage rating, large current carrying capacity, low high-frequency loss, and self-healing ability after instantaneous overload. They are widely used in broadcasting equipment, medical magnetic resonance imaging systems, high-frequency induction heating devices, semiconductor etching equipment, and plasma cleaning equipment. Their core function is to form a resonant circuit with a high-frequency inductor to achieve high-frequency impedance matching, ensuring stable transmission of radio frequency power. They are one of the key components for the reliable operation of various high-frequency equipment.

[0003] Variable vacuum capacitors, as an important branch of vacuum capacitors, achieve dynamic capacitance adjustment by adjusting the coupling length between the moving and stationary electrode groups. Current mainstream variable vacuum capacitors employ a screw-driven adjustment structure: a rotary motor drives a screw to rotate, causing the moving electrode to move axially, thereby changing the coupling area between the moving and stationary electrodes and thus adjusting the capacitance. However, the linear displacement speed of the screw drive is limited; the adjustment time from the maximum capacitance position to the minimum capacitance position (i.e., the maximum working stroke) is generally 3 to 6 seconds, which is no longer suitable for the fast impedance response requirements of next-generation semiconductor etching equipment.

[0004] To address the adjustment speed issue, existing technologies have introduced improved solutions based on electromagnetic drives. For example, CN114974897A, published on August 30, 2022, discloses a fast-change capacitance vacuum capacitor that uses an electromagnet to drive a moving electrode assembly in linear motion, attempting to shorten the adjustment time through the instantaneous response characteristics of electromagnetic force. However, since the movement of the moving electrode assembly directly depends on the magnetic field distribution of the electromagnet, expanding the capacitance switching range (i.e., increasing the electrode travel) requires increasing the electromagnet's attraction force. Increasing the attraction force necessitates increasing the number of coil turns or the excitation current, which inevitably leads to a significant increase in the electromagnet's size and weight, conflicting with the miniaturization and integration trends in semiconductor devices. Furthermore, limited by the effective range of the magnetic field, the actual capacitance switching of this solution is very small, failing to meet users' demands for larger capacitance values ​​and faster matching speeds. Summary of the Invention

[0005] The problem to be solved by the present invention is to provide a variable vacuum capacitor that can quickly switch large capacitance values, so as to overcome the shortcomings of traditional variable capacitors that cannot simultaneously meet the user's needs for switching larger capacitance values ​​and faster matching speed.

[0006] The technical solution adopted by this invention to solve its technical problem is: a variable vacuum capacitor capable of rapidly switching large capacitance values, comprising: A first capacitor, the first capacitor including a first electrode group A and a first electrode group C coupled to each other in a vacuum chamber therein; The second capacitor includes a second electrode group B and a second electrode group C coupled to each other in a vacuum chamber therein, and a moving disk. An intermediate electrode disk is disposed between the first capacitor and the second capacitor, and the first electrode group C and the second electrode group C are respectively fixed on opposite sides of the intermediate electrode disk, and the second electrode group B is electrically connected to the moving disk; the intermediate electrode disk and the moving disk are distributed opposite to each other, and conductive protrusions are provided on the intermediate electrode disk and / or the moving disk; A driving device, connected to the moving disk, is used to drive the moving disk to reciprocate relative to the intermediate electrode disk, so that the second capacitor switches between an open circuit state and a short circuit state. In the short circuit state, the moving disk and the intermediate electrode disk are connected by the conductive protrusion. In the open circuit state, the distance between the moving disk and the intermediate electrode disk is L, and L meets the voltage withstand capability requirement of the second capacitor in the open circuit state.

[0007] As a further improvement of the present invention, the intermediate electrode disk is provided with an access point C that is simultaneously electrically connected to the first electrode group C and the second electrode group C, the first capacitor is provided with an access point A that is electrically connected to the first electrode group A, and the second capacitor is provided with an access point B that is electrically connected to the second electrode group B. The access points A, B and C can be selectively connected to the circuit to realize the first capacitor and the second capacitor being connected in series, in parallel or used independently.

[0008] As a further improvement of the present invention, the second electrode group B and the second electrode group C are both composed of multiple electrode rings of different diameters coaxially spaced together; or the second electrode group B and the second electrode group C are both spiral electrodes, and the two are relatively separated; the conductive protrusion is configured to be surrounded by the second electrode group B and / or the second electrode group C.

[0009] As a further improvement of the present invention, the second capacitor further includes a second insulating shell, a second base, and a conductive second corrugated tube. The second insulating shell is sealed and fixed between the second base and the intermediate electrode disk. The moving disk is located inside the second insulating shell. The second corrugated tube is sealed and connected between the second base and the moving disk. The second electrode group B is fixed to the moving disk, and the second electrode group B and the second corrugated tube are respectively distributed on opposite sides of the moving disk.

[0010] As a further improvement of the present invention, the second capacitor further includes a second insulating shell, a second base, and a conductive second bellows. The second insulating shell is sealed and fixed between the second base and the intermediate electrode disk. The moving disk is located inside the second insulating shell. The second bellows is sealed and connected between the second base and the moving disk. The second electrode group B is fixed to the second base, and both the moving disk and the second bellows are located inside the second electrode group B.

[0011] As a further improvement of the present invention, the first capacitor further includes a first insulating shell and a static electrode disk, the first insulating shell being sealed and fixed between the static electrode disk and the intermediate electrode disk, and the first electrode group A being fixed to the inner end face of the static electrode disk.

[0012] As a further improvement of the present invention, the first capacitor further includes a first insulating shell, a first base, a moving electrode disk, a conductive first bellows, and an adjustment mechanism. The first insulating shell is sealed and fixed between the first base and the intermediate electrode disk. The moving electrode disk is located inside the first insulating shell. The first bellows is sealed and connected between the moving electrode disk and the first base. The first electrode group A is fixed on the moving electrode disk. The adjustment mechanism is driven and connected to the moving electrode disk, and is used to drive the moving electrode disk to move axially to change the coupling length between the first electrode group A and the first electrode group C. The adjustment mechanism includes an adjustment rod and an adjustment nut. One end of the adjustment rod passes axially through the middle of the first base and the first bellows and is fixed to the moving electrode disk. The other end of the adjustment rod extends out of the first capacitor and is threadedly connected to the adjustment nut.

[0013] As a further improvement of the present invention, the conductive protrusion is provided with a conductive contact, and the contact end face of the conductive contact is provided with a right angle or a rounded corner along the edge. The material of the conductive contact is tungsten, tungsten alloy, molybdenum or molybdenum alloy.

[0014] As a further improvement of the present invention, the driving device is an electric cylinder, which is fixedly mounted on the second base by a bracket, and the power output end of the electric cylinder is fixedly connected to the moving plate through the second base and the second bellows via a connecting shaft.

[0015] As a further improvement of the present invention, the driving device is an electromagnet, which includes a positioning cylinder fixedly installed on the second base, an iron core housed in the positioning cylinder, and a coil wound on the iron core; the second capacitor also includes a magnetic plate, which is fixedly connected to the moving disk through a connecting shaft passing through the second base and the second bellows, and the magnetic plate is axially opposite to the iron core; When the electromagnet is de-energized, the moving disk is subjected to atmospheric pressure, causing the moving disk and the intermediate electrode disk to connect and conduct through the conductive boss. When the electromagnet is energized, the iron core is magnetized by the magnetic field generated by the coil and attracts the magnetic plate. The magnetic plate drives the moving disk to move away from the intermediate electrode disk through the connecting shaft, so that the second capacitor switches to the open circuit state.

[0016] The beneficial effects of this invention are as follows: This invention provides a variable vacuum capacitor that can quickly switch between large capacitance values. By adopting a design of a first capacitor connected in series with a second capacitor, the first capacitor ensures a large capacitance value. A driving device drives the moving disk to reciprocate, causing the moving disk and the intermediate electrode disk to separate or connect through conductive protrusions. This changes the short-circuit and open-circuit states of the second capacitor, thereby adjusting the total capacitance value and achieving rapid switching between large capacitance values, thus meeting the user's requirements for rapid impedance matching. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a perspective view of a first embodiment of the variable vacuum capacitor capable of rapidly switching large capacitance values ​​according to the present invention; Figure 2 This is a cross-sectional view of a first embodiment of the variable vacuum capacitor with rapidly switchable large capacitance value of the present invention when the second capacitor is in an open circuit state. Figure 3 This is a cross-sectional view of a first embodiment of the variable vacuum capacitor with rapidly switchable large capacitance value of the present invention when the second capacitor is in a short-circuit state. Figure 4 This is a circuit diagram of the present invention for a variable vacuum capacitor with a large capacitance value that can be quickly switched when the second capacitor is in an open circuit state. Figure 5 This is a circuit diagram of the present invention for a variable vacuum capacitor with a large capacitance value that can be quickly switched when the second capacitor is in a short-circuit state. Figure 6 This is a perspective view of a second embodiment of the variable vacuum capacitor capable of rapidly switching large capacitance values ​​according to the present invention. Figure 7 This is a cross-sectional view of Embodiment 2 of the present invention, which is a variable vacuum capacitor capable of quickly switching large capacitance values, when the second capacitor is in an open-circuit state. Figure 8 This is a cross-sectional view of Embodiment 2 of the present invention, which is a variable vacuum capacitor capable of quickly switching large capacitance values, when the second capacitor is in a short-circuit state. Figure 9 This is a cross-sectional view of Embodiment 3 of the present invention, which is a variable vacuum capacitor capable of quickly switching large capacitance values, when the second capacitor is in a short-circuit state. Figure 10 This is a cross-sectional view of Embodiment 4 of the present invention, which is a variable vacuum capacitor capable of quickly switching large capacitance values, when the second capacitor is in a short-circuit state.

[0019] Referring to the accompanying drawings, the following explanations are provided: 1. First capacitor; 11a. First electrode group A; 11c. First electrode group C; 12. First insulating shell; 13. Static electrode disk; 14. First base; 15. Moving electrode disk; 16. First bellows; 17. Adjusting rod; 18. Adjusting nut; 19. Locking screw; 2. Second capacitor; 21b. Second electrode group B; 21c. Second electrode group C; 23. Moving electrode disk; 24. Second insulating shell; 25. Second base; 26. Second bellows; 3. Intermediate electrode disk; 30. Conductive boss; 301. Conductive contact; 31. Vent hole; 5. Electric cylinder; 51. Power output end; 6. Electromagnet; 61. Positioning cylinder; 62. Iron core; 63. Coil; 7. Bracket; 8. Connecting shaft; 9. Magnetic plate. Detailed Implementation

[0020] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0022] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The illustrations only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the shape, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0023] Additionally, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that practice can be carried out without these specific details.

[0024] The technical solutions provided by the various embodiments of this application are described below with reference to the accompanying drawings.

[0025] Example 1

[0026] See Figures 1 to 3 The present invention provides a variable vacuum capacitor capable of rapidly switching large capacitance values, comprising: a first capacitor 1, a second capacitor 2, an intermediate electrode disk 3, and a driving device.

[0027] The first capacitor 1 includes a first electrode group A11a and a first electrode group C11c, and a vacuum chamber is provided inside the first capacitor 1. The first electrode group A11a and the first electrode group C11c are coupled to each other in the vacuum chamber inside the first capacitor 1. The second capacitor 2 includes a second electrode group B21b, a second electrode group C21c, and a moving disk 23. The second capacitor 2 also has a vacuum chamber provided inside, and the second electrode group B21b and the second electrode group C21c are coupled to each other in the vacuum chamber inside the second capacitor 2.

[0028] Furthermore, the intermediate electrode disk 3 is disposed between the first capacitor 1 and the second capacitor 2. The first electrode group C11c and the second electrode group C21c are respectively fixed on opposite sides of the intermediate electrode disk 3, and the first electrode group C11c and the second electrode group C21c are electrically connected through the intermediate electrode disk 3. In this way, the first capacitor 1 and the second capacitor 2 can be connected in series to form a whole. The second electrode group B21b is electrically connected to the moving disk 23.

[0029] It is worth mentioning that the intermediate electrode disk 3 and the moving disk 23 are distributed opposite to each other, and the intermediate electrode disk 3 and / or the moving disk 23 are provided with conductive protrusions 30.

[0030] The drive unit is connected to the moving disk 23 and can drive the moving disk 23 to reciprocate relative to the intermediate electrode disk 3, thereby switching the second capacitor 2 between an open-circuit state and a short-circuit state. In the short-circuit state, the moving disk 23 and the intermediate electrode disk 3 are connected by conductive protrusions 30. In the open-circuit state, the distance between the moving disk 23 and the intermediate electrode disk 3 is L, and L satisfies the voltage withstand capability requirement of the second capacitor 2 in the open-circuit state.

[0031] It is understandable that if the conductive protrusion 30 is only provided on the intermediate electrode disk 3, then the opening distance L is the distance between the conductive protrusion 30 and the moving disk 23; if the conductive protrusion 30 is only provided on the moving disk 23, then the opening distance L is the distance between the conductive protrusion 30 and the intermediate electrode disk 3; if both the intermediate electrode disk 3 and the moving disk 23 are provided with conductive protrusions 30, then the opening distance L is the distance between the two conductive protrusions 30. Voltage withstand capability refers to the characteristic that, when the opening distance is L, the second capacitor 2 can withstand a certain voltage without electrical breakdown or other electrical performance failures in the open-circuit state.

[0032] This invention employs a design where a first capacitor 1 is connected in series with a second capacitor 2. Based on the first capacitor 1 ensuring a large capacitance value, a driving device is used to drive the moving disk 23 to reciprocate, causing the moving disk 23 and the intermediate electrode disk 3 to separate or connect through the conductive protrusion 30. This changes the short-circuit and open-circuit states of the second capacitor 2, thereby adjusting the total capacitance value and achieving rapid switching of large capacitance values, thus meeting the user's requirements for rapid impedance matching.

[0033] In this invention, the intermediate electrode disk 3 is provided with an access point C that is simultaneously electrically connected to the first electrode group C11c and the second electrode group C21c fixed thereon. The first capacitor 1 is provided with an access point A that is electrically connected to the first electrode group A11a, and the second capacitor 2 is provided with an access point B that is electrically connected to the second electrode group B21b. Access points A, B, and C can be selectively connected to the circuit to realize the series connection, parallel connection, or independent use of the first capacitor 1 and the second capacitor 2. Specifically, as follows: When access point A and access point C are connected to the circuit, the first capacitor 1 and the second capacitor 2 are connected in series to meet the requirements of fast switching of large capacitance value. When access points A and C, and access points B and C are connected to the circuit at the same time, the first capacitor 1 and the second capacitor 2 in the open circuit state can work independently. When access points A, B, and C are all connected to the circuit, and access point A and access point B are electrically connected, the first capacitor 1 and the second capacitor 2 are connected in parallel. This parallel connection mode can extend the upper limit of capacitance value.

[0034] This invention employs a selective access circuit design with access points A, B, and C, enabling the variable vacuum capacitor to operate in three modes: series, parallel, and independent. This significantly improves the device's adaptability to different impedance matching scenarios without requiring additional capacitor replacement.

[0035] It should be noted that, among the above three modes, the present invention focuses more on the series connection mode of the first capacitor 1 and the second capacitor 2 to meet the requirements of rapid switching of large capacitance values, while the other two are extended working modes that users can choose to use as needed.

[0036] See Figure 2 The first capacitor 1 also includes a first insulating shell 12 and a static electrode disk 13. The first insulating shell 12 is a cylindrical tube open at both ends, preferably made of ceramic material, which has excellent insulation properties and helps maintain the vacuum state inside the first capacitor 1. The static electrode disk 13 is sealed and welded to the lower end of the first insulating shell 12, and the first electrode group A11a is fixed to the inner end face of the static electrode disk 13. The upper end of the first insulating shell 12 is sealed and welded to the bottom of the intermediate electrode disk 3 through a connecting ring, thereby forming a sealed space through the intermediate electrode disk 3, the first insulating shell 12, and the static electrode disk 13. After being evacuated, this sealed space forms a vacuum chamber, and the first electrode group A11a and the first electrode group C11c are coupled to each other in the vacuum chamber of the first capacitor 1.

[0037] In this invention, the access point A is configured on the static electrode disk 13, for example, it can be a mounting hole provided on the outer end face of the static electrode disk 13.

[0038] Continue reading Figure 2 The second capacitor 2 also includes a second insulating shell 24, a second base 25, and a conductive second corrugated tube 26. The second insulating shell 24 is also a cylindrical tube with open ends, preferably made of ceramic material; the lower end of the second insulating shell 24 is sealed and welded to the top of the intermediate electrode disk 3 by another connecting ring, and the second base 25 is sealed and welded to the upper end of the second insulating shell 24. The moving disk 23 is located inside the second insulating shell 24 and directly below the second base 25. The second corrugated tube 26 is sealed and connected between the second base 25 and the moving disk 23, thereby forming a sealed space by the second insulating shell 24, the second base 25, the second corrugated tube 26, the moving disk 23, and the intermediate electrode disk 3, and this sealed space forms a vacuum chamber after being evacuated.

[0039] The second electrode group B21b is fixed to the bottom of the moving disk 23, and the second bellows 26 and the second electrode group B21b are respectively distributed on the upper and lower sides of the moving disk 23. The second electrode group B21b and the second electrode group C21c are coupled to each other in the vacuum chamber of the second capacitor 2.

[0040] In this invention, access point B is configured on the second base 25, for example, it can be a mounting hole provided on the outer end face of the second base 25.

[0041] It is worth mentioning that a vent hole 31 is provided on the intermediate electrode disk 3. This vent hole 31 connects the vacuum chamber of the first capacitor 1 and the vacuum chamber of the second capacitor 2, ensuring that the first electrode group A11a and the first electrode group C11c of the first capacitor 1 and the second electrode group B21b and the second electrode group C21c of the second capacitor 2 are in the same vacuum environment. The outer ring of the intermediate electrode disk 3 protrudes radially outward from the cylindrical surface where the first insulating shell 12 / second insulating shell 24 is located. The access point C is disposed on the intermediate electrode disk 3, for example, it can be a mounting hole provided on the protruding part of the outer ring of the intermediate electrode disk 3.

[0042] It should be noted that the intermediate electrode disk 3 can be a single unit, with the first capacitor 1 and the second capacitor 2 sharing one intermediate electrode disk 3; of course, two intermediate electrode disks 3 can also be provided, with the first capacitor 1 and the second capacitor 2 each using an independent intermediate electrode disk 3, and the two intermediate electrode disks 3 being attached to each other and welded together for fixation.

[0043] In this embodiment, both the second electrode group B21b and the second electrode group C21c are composed of multiple electrode rings of different diameters coaxially spaced together. The electrode rings of the second electrode group B21b and the second electrode group C21c are arranged alternately from the inside to the outside, and the spacing between adjacent electrode rings is the same. At the same time, the electrode rings of the second electrode group B21b and the second electrode group C21c extend at least partially into each other, and the relatively overlapping part is the coupling length of the second electrode group B21b and the second electrode group C21c. The open-circuit capacitance of the second capacitor 2 can be precisely controlled by increasing the number of electrode rings or adjusting the ring spacing. In this embodiment, the capacitance of the second capacitor 2 in the open-circuit state is C1.

[0044] Similarly, both the first electrode group A11a and the first electrode group C11c are composed of multiple electrode rings of different diameters coaxially spaced together. The electrode rings of the first electrode group A11a and the first electrode group C11c are arranged alternately from the inside to the outside, and the spacing between adjacent electrode rings is the same. At the same time, the electrode rings of the first electrode group A11a and the first electrode group C11c extend at least partially into each other, and the relatively overlapping part is the coupling length of the electrode rings of the first electrode group A11a and the first electrode group C11c. The capacitance of the first capacitor 1 can be precisely controlled by increasing the number of electrode rings or adjusting the ring spacing. In this embodiment, the capacitance of the first capacitor 1 is C2.

[0045] Of course, in other embodiments of the present invention, the second electrode group B21b and the second electrode group C21c can both be conventional spiral electrodes, which extend outward in a clockwise or counterclockwise direction with the central axis as the reference, and maintain a precisely controlled distance between them. This distance ensures sufficient electrical insulation and achieves efficient electric field coupling. Similarly, the first electrode group A11a and the first electrode group C11c can also be spiral electrodes, which will not be described again.

[0046] In this invention, the conductive protrusion 30 is configured to be surrounded by the second electrode group B21b and / or the second electrode group C21c.

[0047] In this embodiment, specifically, both the intermediate electrode disk 3 and the moving disk 23 are provided with conductive protrusions 30. The conductive protrusions 30 on the intermediate electrode disk 3 and the moving disk 23 are coaxially disposed inside the innermost electrode ring of the second electrode group C21c, and the conductive protrusions 30 on the intermediate electrode disk 3 and the moving disk 23 are axially opposite to each other. By placing the conductive protrusions 30 inside the innermost electrode ring, the coupling area of ​​the electrode ring is not occupied, thus avoiding interference with the capacitance accuracy. This also makes the overall structure of the capacitor compact, reducing the space occupied. Furthermore, the coaxial relative distribution ensures the centering of the moving disk 23 during movement, improving the reliability under short-circuit conditions.

[0048] Preferably, conductive contacts 301 are provided on the opposite end faces of the two conductive protrusions 30. The conductive contacts 301 are made of a material with a high melting point and high hardness, such as tungsten or tungsten alloy, or molybdenum or molybdenum alloy. The contact end faces of the conductive contacts 301 are provided with chamfered right angles or rounded corners along the edges.

[0049] Of course, in other embodiments of the present invention, the conductive protrusion 30 may be only one, disposed on the intermediate electrode disk 3 or the moving disk 23.

[0050] Alternatively, the drive device may be any one of an electric cylinder 5, an electromagnet 6, or a linear motor.

[0051] In this embodiment, the driving device specifically uses an electromagnet 6, which has a fast response speed and can achieve rapid switching of large capacitance values.

[0052] like Figure 2 As shown, the electromagnet 6 includes a positioning cylinder 61, an iron core 62, a coil 63, and a yoke. The positioning cylinder 61 is a hollow cylinder with one open end and the other closed. The open end of the positioning cylinder 61 has a flange, which is fixed to the second base 25 by screws. The iron core 62, the coil 63, and the yoke are all housed inside the positioning cylinder 61. The yoke is cup-shaped, and the iron core 62 is coaxially disposed inside the yoke and fixed to the positioning cylinder 61 by screws. The coil 63 is located inside the yoke and distributed around the iron core 62. The yoke enhances the attraction of the iron core 62 to the magnetic plate 9.

[0053] The second capacitor 2 also includes a magnetic plate 9, which is fixedly connected to the moving disk 23 via a connecting shaft 8 through the second base 25 and the second bellows 26, and the magnetic plate 9 is axially opposite to the iron core 62.

[0054] Preferably, the positioning cylinder 61 and the connecting shaft 8 in this invention are both made of insulating material, which can isolate the electromagnet 6 from the second capacitor 2, block the high voltage conduction to the electromagnet 6, and prevent interference to the electromagnet 6.

[0055] It should be noted that this application does not strictly limit the materials of the positioning cylinder 61 and the connecting shaft 8. Both can be made of non-insulating materials. In practical applications, the appropriate material type can be flexibly selected based on actual factors such as the equipment's usage scenario, high-voltage protection design requirements, processing conditions, and production cost control. Regardless of whether an insulating or non-insulating material is used, as long as it meets the core usage requirements such as the installation and positioning of the positioning cylinder 61 and the stable power transmission of the connecting shaft 8, it can be applied to the technical solution of this invention and will not have a substantial impact on the core technical effects of rapid switching with high capacity achieved in this application.

[0056] When the electromagnet 6 is de-energized, due to the pressure difference between the inside and outside of the second bellows 26, the moving disk 23 is subjected to atmospheric pressure, causing the moving disk 23 and the intermediate electrode disk 3 to connect and conduct through the conductive boss 30. At this time, the second capacitor 2 is in a short-circuit state.

[0057] When the electromagnet 6 is energized, the iron core 62 is magnetized by the magnetic field generated by the coil 63 and attracts the magnetic plate 9. The magnetic plate 9 drives the moving disk 23 and the second electrode group B21b to move away from the middle electrode disk 3 through the connecting shaft 8. The conductive protrusion 30 of the moving disk 23 separates from the conductive protrusion 30 of the middle electrode disk 3 and maintains an open distance L, so that the second capacitor 2 switches to the open circuit state.

[0058] The following section takes the first capacitor 1 and the second capacitor 2 connected in series as an example, that is, the connection points A and B are connected in the circuit, and the connection point C is left floating, and provides a detailed description of the capacitance change of the second capacitor 2 during the switching process between short circuit and open circuit states.

[0059] like Figure 3 and Figure 5 As shown, when the second capacitor 2 is in a short-circuit state, the capacitance of the second capacitor 2 can be regarded as 0, and the total capacitance of the variable vacuum capacitor is the capacitance of the first capacitor 1, i.e., C2.

[0060] like Figure 2 and Figure 4 As shown, when the second capacitor 2 switches from a short-circuit state to an open-circuit state, the capacitance of the second capacitor 2 is C1. C1 and C2 are connected in series through the intermediate electrode disk 3. At this time, the total capacitance of the variable vacuum capacitor is C = C1 × C2 / (C1 + C2), and C < C1. It can be seen that when switching from a short-circuit state to an open-circuit state, the total capacitance of the variable vacuum capacitor changes by ΔC = C2 - C.

[0061] Therefore, by designing the capacitance C1 of the second capacitor 2 in the open circuit state to be much smaller than the capacitance C2 of the first capacitor 1, and since C is smaller than C1, the switching capacitance ΔC when switching from short circuit to open circuit state is greater than C2-C1, thus achieving a large capacitance value switching.

[0062] Preferably, when the second capacitor 2 is in an open-circuit state, the distance L between the conductive protrusion 30 on the intermediate electrode disk 3 and the conductive protrusion 30 on the moving disk 23 is minimized while meeting the voltage withstand capability requirements of the second capacitor 2 in the open-circuit state. Generally, L is slightly larger than the electrode spacing. Since the distance between the upper and lower conductive protrusions 30 is small, the time required to switch from open circuit to short circuit is short. Regardless of whether the moving disk 23 is driven by an electric cylinder 5, an electromagnet 6, or a linear motor, the required stroke is the distance L between the conductive protrusions 30. The stroke for switching capacitance is very short, thus breaking through the limitations of traditional adjustment speed and achieving rapid switching of large capacitance values.

[0063] Example 2

[0064] The difference between this embodiment and Embodiment 1 is that the driving device is different. The driving device in this embodiment is specifically an electric cylinder 5, preferably a hollow servo electric cylinder, which can be purchased directly from the market and has the core advantages of high linearity and high repeatability positioning accuracy. Its electric cylinder screw serves as the power output end 51, with stable output and fast response speed, realizing rapid switching of large capacitance values ​​and meeting the user's requirements for rapid matching of impedance matching devices.

[0065] See Figures 6 to 8 The variable vacuum capacitor that can quickly switch large capacitance values ​​also includes a bracket 7 and a connecting shaft 8. A positioning hole is provided in the middle of the second base 25. The power output end 51 of the electric cylinder 5 extends through the positioning hole into the second bellows 26. The connecting shaft 8 is coaxially fixed between the power output end 51 and the moving plate 23 to achieve an insulated connection between the power output end 51 and the moving plate 23. While ensuring stable power transmission, it avoids high voltage being conducted to the electric cylinder 5 through the transmission path.

[0066] Furthermore, the bracket 7 is fixed to the second base 25 to support and fix the electric cylinder 5. Specifically, the bracket 7 is a tubular shape with open ends and a hollow interior, through which the power output end 51 passes; both the upper and lower ends of the bracket 7 are provided with outer flanges, and the lower end of the bracket 7 extends axially to form a positioning ring, which fits into the positioning hole of the second base 25 to determine the radial position of the bracket 7; the two outer flanges are respectively fixedly connected to the electric cylinder 5 and the second base 25 by screws.

[0067] Preferably, the bracket 7 in this invention is made of an insulating material, which not only securely fixes the electric cylinder 5 and the second capacitor 2, but also blocks high-voltage conduction through the insulating material, forming double insulation protection with the connecting shaft 8. Similarly, this application does not strictly limit the material of the bracket 7, and both can also be made of non-insulating materials.

[0068] Taking the first capacitor 1 and the second capacitor 2 connected in series as an example, the second capacitor 2 is in an open circuit state in the initial state, and the total capacitance of the variable vacuum capacitor is C=C1×C2 / (C1+C2). When it is necessary to switch the capacitance value, the electric cylinder 5 drives the power output end 51 to extend downward. The power output end 51 drives the moving disk 23 to move linearly towards the middle electrode disk 3 through the connecting shaft 8 until the conductive protrusion 30 on the moving disk 23 abuts against the conductive protrusion 30 on the middle electrode disk 3, so that the second capacitor 2 switches to a short circuit state. At this time, the total capacitance of the variable vacuum capacitor is the capacitance value of the first capacitor 1, that is, C2.

[0069] Therefore, the variable vacuum capacitor of the present invention, which can quickly switch large capacitance values, adopts a design of a first capacitor 1 connected in series with a second capacitor 2. Based on the first capacitor 1 ensuring a large capacitance value, the moving disk 23 is driven by a driving device to perform reciprocating motion, so that the moving disk 23 and the intermediate electrode disk 3 are separated or connected through the conductive protrusion 30. This changes the short-circuit and open-circuit state of the second capacitor 2, thereby adjusting the total capacitance value and realizing the rapid switching of large capacitance values, thus meeting the user's requirements for rapid matching of impedance matching devices.

[0070] Example 3

[0071] The difference between this embodiment and Embodiment 1 is that the structure of the second capacitor 2 is different.

[0072] See Figure 9 The second capacitor 2 also includes a second insulating shell 24, a second base 25, and a conductive second corrugated tube 26. The second insulating shell 24 is also a round tube with open ends, preferably made of ceramic material. The lower end of the second insulating shell 24 is sealed and welded to the top of the intermediate electrode disk 3 by a connecting ring, and the second base 25 is sealed and welded to the upper end of the second insulating shell 24.

[0073] The moving disk 23 is located in the space formed by the second insulating shell 24, the second base 25 and the intermediate electrode disk 3. The upper and lower ends of the second bellows 26 are respectively sealed and welded to the second base 25 and the moving disk 23. Thus, the second insulating shell 24, the second base 25, the second bellows 26, the moving disk 23 and the intermediate electrode disk 3 form a closed space, and the closed space forms a vacuum chamber after being evacuated.

[0074] Similar to Embodiment 1, access point B in this embodiment is also configured on the second base 25.

[0075] In this embodiment, the second electrode group C21c is also fixed to the top of the intermediate electrode disk 3, but the second electrode group B21b is directly fixed to the inner end face of the second base 25. The second electrode group B21b and the second electrode group C21c are coupled to each other in the vacuum chamber of the second capacitor 2. At the same time, the moving disk 23 and the second bellows 26 are both located inside the second electrode group B21b.

[0076] When the electromagnet 6 is de-energized, due to the pressure difference between the inside and outside of the second bellows 26, the moving disk 23 is subjected to atmospheric pressure, causing the moving disk 23 and the intermediate electrode disk 3 to abut and conduct through the conductive boss 30. At this time, a circuit is formed between the second base 25, the second bellows 26, the moving disk 23 and the intermediate electrode disk 3, and the second capacitor 2 is in a short-circuit state.

[0077] When the electromagnet 6 is energized, the iron core 62 is magnetized by the magnetic field generated by the coil 63 and attracts the magnetic plate 9. The magnetic plate 9 drives the moving disk 23 to move away from the intermediate electrode disk 3 through the connecting shaft 8. The conductive protrusion 30 of the moving disk 23 separates from the conductive protrusion 30 of the intermediate electrode disk 3, so that the second capacitor 2 switches to the open circuit state.

[0078] In this embodiment, by reducing the diameter of the moving disk 23 and the second bellows 26, and by directly welding the second electrode group B21b to the inner end face of the second base 25, this structural design can reduce the mass of the moving end and further improve the switching speed. Furthermore, during the switching process, the positions of the second electrode group B21b and the second electrode group C21c do not change, so the change in capacitance before and after switching is more stable and reliable.

[0079] Example 4

[0080] The difference between this embodiment and Embodiment 1 is that the structure of the first capacitor 1 is different.

[0081] See Figure 10 In addition to the first electrode group A11a and the first electrode group C11c, the first capacitor 1 also includes a first insulating shell 12, a first base 14, a moving electrode disk 15, a conductive first bellows 16, and an adjustment mechanism. The first insulating shell 12 is also a cylindrical tube with open ends, preferably made of ceramic material; the upper end of the first insulating shell 12 is sealed and welded to the top of the intermediate electrode disk 3 by a connecting ring, and the first base 14 is sealed and welded to the lower end of the first insulating shell 12.

[0082] The moving electrode disk 15 is located in the space formed by the first insulating shell 12, the first base 14 and the intermediate electrode disk 3. The upper and lower ends of the first bellows 16 are respectively sealed and welded to the moving electrode disk 15 and the first base 14. Thus, the first insulating shell 12, the first base 14, the first bellows 16, the moving electrode disk 15 and the intermediate electrode disk 3 form a closed space, and the closed space forms a vacuum chamber after being evacuated.

[0083] In this embodiment, the first electrode group C11c is also fixed to the bottom of the intermediate electrode disk 3, but the first electrode group A11a is fixed to the top of the moving electrode disk 15, and the first electrode group A11a and the first electrode group C11c are coupled to each other in the vacuum chamber of the first capacitor 1.

[0084] In this embodiment, access point A is configured on the first base 14.

[0085] Furthermore, the adjustment mechanism is connected to the moving electrode disk 15 and is used to drive the moving electrode disk 15 to move axially to change the coupling length between the first electrode group A11a and the first electrode group C11c, thereby realizing the adjustable capacitance of the first capacitor 1.

[0086] Specifically, the adjustment mechanism includes an adjustment rod 17 and an adjustment nut 18. The upper end of the adjustment rod 17 passes through the middle of the first base 14 and the first bellows 16 along the axial direction and is fixed to the moving electrode disk 15. The other end of the adjustment rod 17 extends vertically downward beyond the first capacitor 1. The other end of the adjustment rod 17 is provided with an external thread for threaded connection with the adjustment nut 18.

[0087] Due to the pressure difference between the inside and outside of the first bellows 16, the moving electrode disk 15 is subjected to atmospheric pressure, causing the adjusting nut 18, which is threadedly connected to the adjusting rod 17, to always remain against the outer end face of the first base 14. When the adjusting nut 18 is rotated, the adjusting rod 17 moves up and down, which in turn moves the moving electrode disk 15 and the first electrode group A11a up and down, changing the coupling length between the first electrode group A11a and the first electrode group C11c, thereby changing the capacitance value of C2 to meet the user's need for more capacitance value selection.

[0088] In addition, a locking screw 19 can be provided on the adjusting nut 18. After the adjustment of the C2 value is completed, the adjusting nut 18 and the adjusting rod 17 can be locked by the locking screw 19 to prevent loosening and fix the size of the C2 value.

[0089] It is understood that the driving device in Embodiments 3 and 4 above is not limited to the electromagnet 6, and can also be the electric cylinder 5 as described in Embodiment 2.

[0090] The same or similar parts between the various embodiments in this specification can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments.

[0091] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A variable vacuum capacitor capable of rapidly switching large capacitance values, characterized in that, include: The first capacitor (1) includes a first electrode group A (11a) and a first electrode group C (11c) coupled to each other in a vacuum chamber therein. The second capacitor (2) includes a second electrode group B (21b) and a second electrode group C (21c) coupled to each other in a vacuum chamber therein, and a moving disk (23). An intermediate electrode disk (3) is disposed between the first capacitor (1) and the second capacitor (2), and the first electrode group C (11c) and the second electrode group C (21c) are respectively fixed on opposite sides of the intermediate electrode disk (3), and the second electrode group B (21b) is electrically connected to the moving sub-disk (23); the intermediate electrode disk (3) and the moving sub-disk (23) are distributed opposite to each other, and conductive protrusions (30) are provided on the intermediate electrode disk (3) and / or the moving sub-disk (23); A driving device is connected to the moving disk (23) for driving the moving disk (23) to reciprocate relative to the intermediate electrode disk (3) so that the second capacitor (2) switches between an open circuit state and a short circuit state. In the short circuit state, the moving disk (23) and the intermediate electrode disk (3) are connected by the conductive protrusion (30). In the open circuit state, the distance between the moving disk (23) and the intermediate electrode disk (3) is L, and L satisfies the voltage withstand capability requirement of the second capacitor (2) in the open circuit state.

2. The variable vacuum capacitor capable of rapidly switching large capacitance values ​​according to claim 1, characterized in that, The intermediate electrode disk (3) is provided with an access point C that is electrically connected to both the first electrode group C (11c) and the second electrode group C (21c). The first capacitor (1) is provided with an access point A that is electrically connected to the first electrode group A (11a). The second capacitor (2) is provided with an access point B that is electrically connected to the second electrode group B (21b). The access points A, B and C can be selectively connected to the circuit to realize that the first capacitor (1) and the second capacitor (2) can be connected in series, in parallel or used independently.

3. The variable vacuum capacitor capable of rapidly switching large capacitance values ​​according to claim 1, characterized in that, The second electrode group B (21b) and the second electrode group C (21c) are both composed of multiple electrode rings of different diameters coaxially spaced together; or the second electrode group B (21b) and the second electrode group C (21c) are both spiral electrodes and are separated from each other; the conductive protrusion (30) is configured to be surrounded by the second electrode group B (21b) and / or the second electrode group C (21c).

4. The variable vacuum capacitor capable of rapidly switching large capacitance values ​​according to claim 3, characterized in that, The second capacitor (2) further includes a second insulating shell (24), a second base (25), and a conductive second corrugated tube (26). The second insulating shell (24) is sealed and fixed between the second base (25) and the intermediate electrode disk (3). The moving disk (23) is located inside the second insulating shell (24). The second corrugated tube (26) is sealed and connected between the second base (25) and the moving disk (23). The second electrode group B (21b) is fixed to the moving disk (23), and the second electrode group B (21b) and the second corrugated tube (26) are respectively distributed on opposite sides of the moving disk (23).

5. The variable vacuum capacitor capable of rapidly switching large capacitance values ​​according to claim 3, characterized in that, The second capacitor (2) further includes a second insulating shell (24), a second base (25), and a conductive second corrugated tube (26). The second insulating shell (24) is sealed and fixed between the second base (25) and the intermediate electrode disk (3). The moving disk (23) is located inside the second insulating shell (24). The second corrugated tube (26) is sealed and connected between the second base (25) and the moving disk (23). The second electrode group B (21b) is fixed to the second base (25), and the moving disk (23) and the second corrugated tube (26) are both located inside the second electrode group B (21b).

6. The variable vacuum capacitor capable of rapidly switching large capacitance values ​​according to claim 3, characterized in that, The first capacitor (1) further includes a first insulating shell (12) and a static electrode disk (13). The first insulating shell (12) is sealed and fixed between the static electrode disk (13) and the intermediate electrode disk (3). The first electrode group A (11a) is fixed to the inner end face of the static electrode disk (13).

7. The variable vacuum capacitor capable of rapidly switching large capacitance values ​​according to claim 3, characterized in that, The first capacitor (1) further includes a first insulating shell (12), a first base (14), a moving electrode disk (15), a conductive first bellows (16), and an adjustment mechanism. The first insulating shell (12) is sealed and fixed between the first base (14) and the intermediate electrode disk (3). The moving electrode disk (15) is located inside the first insulating shell (12). The first bellows (16) is sealed and connected between the moving electrode disk (15) and the first base (14). The first electrode group A (11a) is fixed on the moving electrode disk (15). The adjustment mechanism is connected to the transmission mechanism. The adjustment mechanism is connected to the moving electrode disk (15), which is used to drive the moving electrode disk (15) to move axially to change the coupling length between the first electrode group A (11a) and the first electrode group C (11c); the adjustment mechanism includes an adjustment rod (17) and an adjustment nut (18). One end of the adjustment rod (17) passes through the middle of the first base (14) and the first bellows (16) axially and is fixed to the moving electrode disk (15). The other end of the adjustment rod (17) extends out of the first capacitor (1) and is threadedly connected to the adjustment nut (18).

8. The variable vacuum capacitor capable of rapidly switching large capacitance values ​​according to claim 1, characterized in that, The conductive boss (30) is provided with a conductive contact (301), and the contact end face of the conductive contact (301) is provided with a right angle or a rounded corner along the edge. The material of the conductive contact (301) is tungsten, tungsten alloy, molybdenum or molybdenum alloy.

9. The variable vacuum capacitor capable of rapidly switching large capacitance values ​​according to claim 4 or 5, characterized in that, The drive device is an electric cylinder (5), which is fixedly installed on the second base (25) by a bracket (7), and the power output end (51) of the electric cylinder (5) is fixedly connected to the moving plate (23) through a connecting shaft (8) passing through the second base (25) and the second bellows (26).

10. The variable vacuum capacitor capable of rapidly switching large capacitance values ​​according to claim 4 or 5, characterized in that, The driving device is an electromagnet (6), which includes a positioning cylinder (61) fixedly installed on the second base (25), an iron core (62) housed in the positioning cylinder (61), and a coil (63) wound on the iron core (62); the second capacitor (2) also includes a magnetic plate (9), which is fixedly connected to the moving disk (23) through a connecting shaft (8) passing through the second base (25) and the second bellows (26), and the magnetic plate (9) and the iron core (62) are axially opposite to each other; When the electromagnet (6) is de-energized, the moving disk (23) is subjected to atmospheric pressure, causing the moving disk (23) and the intermediate electrode disk (3) to connect and conduct through the conductive boss (30); When the electromagnet (6) is energized, the iron core (62) is magnetized by the magnetic field generated by the coil (63) and attracts the magnetic plate (9). The magnetic plate (9) drives the moving disk (23) to move away from the intermediate electrode disk (3) through the connecting shaft (8) so that the second capacitor (2) switches to the open circuit state.

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