Sealing structure of high-voltage plug of electron gun and electron gun

Abstract

The invention discloses a sealing structure of a high-voltage plug of an electronic gun and the electronic gun. The sealing structure of the high-voltage plug of the electronic gun comprises a base, a shell, the high-voltage plug and an air valve. A terminal is arranged on the base; the shell is of a hollow structure and comprises a first end and a second end which are connected to the upper surface of the base, a through hole is formed in the first end, and an insertion hole is formed in the second end; the high-voltage plug is plugged in the plugging hole and passes through the through hole, and the end part, passing through the through hole, of the high-voltage plug is provided with a male head which is in contact with the terminal and is electrically conducted; the first end of the shell is in closed fit with the base, and the peripheral surface of the high-voltage plug is in closed fit with the inner wall surface of the plugging hole; the air valve is installed outside the shell and communicated with the inner cavity of the shell, and the air valve is used for sealing the inner cavity of the shell when the inner cavity of the shell is in a vacuum state or after the inner cavity of the shell is filled with insulating gas. The sealing device has the advantages of being good in sealing effect, good in insulating performance, easy to install, convenient to transport and easy to operate.

Description

Technical Field

[0001] The invention relates to the technical field of electron guns, and in particular to a sealing structure of a high-voltage plug of an electron gun and an electron gun. Background Art

[0002] At present, most high-voltage plugs of high-voltage electron guns on the market are sealed with soft materials such as silicone to reduce the flow of positive and negative charge carriers on the surface of the insulator in the high-voltage area or the air in the high-voltage area. It has a certain effect on surface discharge and glow discharge under high-voltage environment. However, because the effect of silicone sealing may be flawed, this flaw has the risk of unstable performance in the high-voltage joint environment of 100kv. This risk will cause damage to electronic components such as electron sources and chips, causing irreversible damage to the system. Silicone sealing has a general insulation effect and is generally used for field emission electron guns with an acceleration voltage below 120kV. When the high voltage reaches 100kv or 120kv, the performance is unstable. At the same time, the silicone sealing structure makes it difficult to plug and unplug the high-voltage plug. The sealing effect and the ease of plugging and unplugging are in an inverse contradiction. The better the sealing, the more difficult it is to plug and unplug, and the sealing that is easy to plug and unplug has a poor insulation effect. Therefore, a new plug contact form is urgently needed, which can eliminate or change the physical mechanism of surface discharge and glow discharge, and can be simply realized in the manufacturing structure, with operability and enhanced ease of use. Summary of the invention

[0003] In view of the deficiencies of the prior art, the first object of the present invention is to provide a sealing structure for a high-voltage plug of an electron gun, which has good sealing effect, good insulation performance and is easy to install.

[0004] A second objective of the present invention is to provide an electron gun.

[0005] To achieve the above-mentioned purpose 1, the present invention adopts the following technical solution:

[0006] The sealing structure of the electron gun high-voltage plug comprises a base, a shell, a high-voltage plug, and a gas valve; a terminal is arranged on the base;

[0007] The shell is a hollow structure, which includes a first end connected to the upper surface of the base and a second end opposite to the first end, the first end is provided with a through hole extending from the inner cavity of the shell to the outer surface of the first end, and the second end is provided with a plug hole extending from the inner cavity of the shell to the outer surface of the second end; the high-voltage plug is inserted into the plug hole and passes through the through hole, and the end of the plug that passes through the through hole is provided with a male plug that contacts and is electrically connected with the terminal;

[0008] The first end of the shell is tightly matched with the base, and the outer peripheral surface of the high-voltage plug is tightly matched with the inner wall surface of the plug hole;

[0009] The gas valve is installed outside the shell and communicated with the inner cavity of the shell. The gas valve is used to close the inner cavity of the shell when the inner cavity of the shell is in a vacuum state or when the inner cavity of the shell is filled with insulating gas.

[0010] Preferably, the shell includes a cylindrical side wall and an end wall located at the second end and extending radially inward from the inner side of the side wall along the shell, the plug hole is opened on the end wall, and the through hole is surrounded by the part extending from the side wall to the first end.

[0011] Preferably, the thickness of the end wall is h, where h is greater than or equal to 8 mm; the inner wall surface of the plug-in hole is provided with a first groove extending along its circumference, the outer circumferential surface of the high-voltage plug is provided with a second groove extending along its circumference, and a first annular seal is provided between the outer circumferential surface of the high-voltage plug and the inner wall surface of the plug-in hole, and a part of the first annular seal is embedded in the first groove and the other part is embedded in the second groove.

[0012] Preferably, the inner wall surface of the plug hole is offset by a distance d relative to the inner side surface of the side wall toward the central axis of the shell, wherein d≥6 mm.

[0013] Preferably, the first end of the shell is provided with a connection disk extending radially outward from the outer side surface of the side wall along the shell, and the connection disk is in contact with the upper surface of the base.

[0014] Preferably, an annular third groove is provided on the upper surface of the base, an annular fourth groove is provided on the lower surface of the connecting disk, and a second annular seal is provided between the base and the connecting disk, with a portion of the second annular seal being embedded in the third groove and the other portion being embedded in the fourth groove.

[0015] Preferably, the base and the connecting plate are fixed together by a plurality of locking bolts passing through the two.

[0016] Preferably, the upper surface of the base is recessed downward to form a receiving groove, which is arranged opposite to the plug-in hole, and the part of the high-voltage plug passing through the through hole is embedded in the receiving groove. The bottom surface of the receiving groove is provided with a blind hole extending downward for the male plug to pass through, and the terminal is placed in the blind hole.

[0017] Preferably, a quick-connect flange is fixedly connected to the shell, the air valve is fixed on the quick-connect flange, and the mutually butting surfaces of the air valve and the quick-connect flange are tightly matched.

[0018] To achieve the above-mentioned second objective, the present invention adopts the following technical solution:

[0019] An electron gun comprises the sealing structure of the electron gun high voltage plug.

[0020] The beneficial effects of the present invention are:

[0021] The present invention places the high-voltage plug in the inner cavity of the shell, and can form a vacuum environment in the inner cavity where the high-voltage plug is located through the gas valve, or fill the inner cavity with insulating gas through the gas valve so that the inner cavity where the high-voltage plug is located is filled with insulating gas, thereby insulating and packaging the high-voltage plug in an airtight manner, which has good sealing effect, good insulation performance, and is easy to install, while also having the advantages of convenient transportation and easy operation. With better sealing and insulation performance, it is suitable for the insulation structure of the high-voltage plug of the high-voltage field emission electron gun, and effectively prevents negative phenomena caused by high voltage such as electrical breakdown and creepage. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the present invention;

[0023] Figure 2 It is the installation schematic diagram of the present invention;

[0024] Figure 3 is a cross-sectional view of the present invention;

[0025] Figure 4 for Figure 3 A schematic diagram of the structure of the middle shell;

[0026] Figure 5 for Figure 4 Cross-sectional view of the middle shell. DETAILED DESCRIPTION

[0027] Below, in conjunction with the accompanying drawings and specific embodiments, the present invention is further described:

[0028] like Figure 1 , 2, 3, and 4 show a sealing structure of a high-voltage plug of an electron gun of the present invention, which includes a base 10, a shell 20, a high-voltage plug 30, and a gas valve 40. The base 10 can be a flange, a metal plate, or a plastic plate. The present invention preferably uses a flange as the base 10, and a terminal (not shown in the figure) is arranged on the base 10. The shell 10 is a hollow structure, which preferably adopts a columnar structure, including a first end 201 and a second end 202 opposite to the first end 201. The first end 201 is connected to the upper surface 101 of the base 10 and is fixedly connected to the base 10. A through hole 23 extending from the inner cavity 203 of the shell 20 to the outer surface of the first end 201 is arranged on the first end 201, and a through hole 23 extending from the inner cavity 203 of the shell 20 to the outer surface of the first end 201 is arranged on the second end 202. 0 extends to the plug hole 22 on the outer surface of the second end 202, the aperture of the plug hole 22 is equivalent to the outer diameter of the high-voltage plug 30, so that the high-voltage plug 30 can be inserted into the plug hole 22 from the outside of the first end 202 of the shell 10, the inner diameter of the through hole 23 is larger than the outer diameter of the high-voltage plug 30, so that the high-voltage plug 30 can pass through the through hole 23 while the outer surface of the high-voltage plug 30 and the inner wall clearance of the through hole 23 are matched, after the high-voltage plug 30 is inserted from the outside of the second end 202 of the shell 20 through the plug hole 22, the high-voltage plug 30 passes through the inner cavity 203 and through the through hole 23, and the end of the high-voltage plug 30 passing through the through hole 23 is configured with a male connector 31, and the male connector 31 contacts and is electrically conductive with the terminal on the base 10.The plug-in hole 22 on the shell 20 is used to ensure that the high-voltage plug 30 can be inserted into the inner cavity of the shell 20 and the high-voltage plug 30 can be assembled in the shell 20. The through hole 23 is used to allow the high-voltage plug 30 to pass through it. In order to ensure the airtightness of the chamber 203, at the first end 201 of the shell 20, the through hole 23 is covered with the base 10, and the first end 201 of the shell 20 is tightly matched with the base, and the outer peripheral surface of the high-voltage plug 30 is tightly matched with the inner wall surface of the plug-in hole 22. It should be noted that in order to facilitate the insertion of the high-voltage plug 30 into the plug-in hole 22 and ensure that the gap between the two has better sealing performance, it is necessary to better control the outer diameter of the high-voltage plug 30 and the inner diameter of the plug-in hole 22; the air valve 40 is installed on the outside of the shell 20 And it is communicated with the inner cavity 203 of the shell 20. Since the above-mentioned through hole 23 and the plug hole 22 are all sealed, the air valve 40 is the only part of the inner cavity 203 that is connected to the outside world. The air valve 40 can be connected to the external vacuum pumping device. When the inner cavity 203 is formed into a vacuum state by the vacuum pumping device, the air valve 40 is closed to form a vacuum state in the inner cavity 203 of the shell 21; of course, when the inner cavity 20 is formed into a vacuum state, insulating gases such as nitrogen, carbon dioxide, and sulfur hexafluoride can be injected into the inner cavity 203 through the air valve 40, and the air valve 40 can be closed after the insulating gas fills the inner cavity 203; the air valve 40 is arranged on the shell 20, and the insulation of the high-voltage plug can be achieved by forming a vacuum inside the inner cavity 203 or filling the inner cavity 203 with insulating gas.

[0029] In a preferred embodiment, the shell 20 includes a cylindrical side wall 21 and an end wall 24 located at the second end 202. The end wall 24 extends inward from the inner side of the side wall 21 along the radial direction of the shell 20, which is equivalent to using the end wall 24 to form a structure in which the side wall 21 is open at one end and the other end is a blind end. The plug hole 22 is processed on the end wall 24 by machining or other processing methods, and the part of the side wall 21 extending to the first end 201 is surrounded by a through hole 23. In this way, the inner diameter of the through hole 23 is consistent with the inner diameter of the inner cavity 203, and the inner diameter of the plug hole 22 is smaller than the inner diameter of the inner cavity 203. After the high-voltage plug 30 is assembled in the shell 20, there is a sufficient gap between the outer peripheral surface of the high-voltage plug 30 and the inner wall of the inner cavity 203. That is, the inner cavity 203 still has enough space to form a vacuum area after accommodating the high-voltage plug 30, or has enough space to accommodate insulating gas. After the high-voltage plug 30 is inserted into the plug hole 22, the assembly gap between its outer circumferential surface and the inner wall surface of the plug hole 22 is sealed by an annular seal 60. Specifically, a groove 221 extending along its circumferential direction is provided on the inner wall surface of the plug hole 22, and a groove 301 extending along its circumferential direction is provided on the outer circumferential surface of the high-voltage plug 30. After the high-voltage plug 30 is inserted into the plug hole 22 and installed in place with the housing 20, the groove 221 and the groove 301 are opposite to each other, and the two together constitute an annular groove for accommodating the annular seal 60, that is, the annular seal 60 is placed between the outer circumferential surface of the high-voltage plug 30 and the inner wall surface of the plug hole 22, a part of which is embedded in the groove 221, and the other part is embedded in the groove 301, using The grooves 221 and 301 position the annular seal 60 axially to prevent the annular seal 60 from axially moving along the plug hole 22. The annular seal 60 is tightly matched with the inner surfaces of the grooves 221 and 301. Preferably, the annular seal 60 can be a silicone seal ring with a large deformation, such as a commonly used O-ring. In other embodiments, the annular seal 60 can also be a component with good rigidity but can also achieve good sealing after being fully squeezed. For example, it can be a ring-shaped sealing structure made of metal materials (such as copper, aluminum, etc.) and placed in the above-mentioned annular groove. In short, components that can be used to seal the matching gap formed between two mutually sleeved components can be used as the above-mentioned annular seal 60. The thickness of the end wall 24 is h, which is ≥8mm, so that the thickness of the end wall 24 can be adapted to the width of the above-mentioned groove 221, and the other parts of the plug hole 22 without the groove 221 have a relatively large axial dimension to better support the high-voltage plug 30. Of course, the size of the end wall 24 can also be a larger value in the above-mentioned size range. Two of the above-mentioned grooves 221 are set on the inner wall surface of the plug hole 22, and two of the above-mentioned grooves 301 are set on the outer peripheral surface of the high-voltage plug 30. Thus, two annular seals 60 staggered along the axial direction can be set between the inner wall surface of the plug hole 22 and the outer peripheral surface of the high-voltage plug 30 to further improve the sealing performance.

[0030] In the above structure, since the high-voltage plug 30 is fixedly matched with the shell 10 by using the plug hole 22, the aperture of the plug hole 22 is smaller than the inner diameter of the inner cavity 203. Therefore, the distance between the inner wall surface of the plug hole 22 and the inner side surface of the side wall 21 determines the size of the gap between the high-voltage plug 30 and the inner side surface of the side wall 21. In the present invention, it is preferred to offset the inner wall surface of the plug hole 22 relative to the inner side surface of the side wall 21 in the direction of the central axis of the shell 20 by a distance d, so that the distance d is ≥ 6 mm. In this way, the inner cavity 203 still has enough space to form a vacuum area after accommodating the high-voltage plug 30, or has enough space to accommodate insulating gas.

[0031] Since the first end 201 of the shell 20 and the upper surface 101 of the base 10 are butt-fitted, in order to enable the two to be better sealed after the butt-fitting and to better fix the shell 20 on the base 10, a connecting plate 205 extending radially outward from the outer side of the side wall 21 along the shell 20 is provided at the first end 201 of the shell 20. The connecting plate 205 is abutted against the upper surface 101 of the base 10. The connecting plate 205 can be regarded as a flange provided at the first end 201 of the shell 20. When the base 10 is also a flange, it can be regarded as connecting the two flanges together to fix the shell 20 to the base 10. When both the connecting plate 205 and the base 10 are flanges, the sealing of the two will also become easy to implement. For example, an annular groove 13 may be provided on the upper surface 101 of the base 10, and correspondingly, an annular groove 251 may be provided on the lower surface of the connecting disk 205. The groove 13 and the groove 251 are arranged opposite to each other up and down, and the two together constitute an annular groove, in which an annular seal 70 is embedded, that is, a part of the annular seal 70 is embedded in the groove 13, and the other part is embedded in the groove 251. Similar to the above-mentioned annular seal 60, the annular seal 70 may be a silicone sealing ring such as an O-ring, or may be an annular sealing structure made of metal material (such as copper, aluminum, etc.) and placed in the above-mentioned annular groove. The base 10 is provided with a plurality of bolt holes, and the connecting plate 25 is also provided with a plurality of bolt holes. The plurality of bolt holes on the two are arranged in a circumferential array. The bolt holes on the connecting plate 25 correspond to the bolt holes on the base 10 one by one. The connecting plate 25 can be fixed on the base 10 by passing the locking bolts through the bolt holes on the connecting plate 25 and the base 10. The nuts on the bolts are tightened to tighten the connecting plate 25 and the base 10. While ensuring that the two are tightly matched, the annular seal 70 can be squeezed to fully deform the annular seal 70 to meet the sealing requirements. When the connecting plate 25 and the base 10 are both flanges, the sealing between the two can also be a knife-edge flange seal, or a sealing gasket is clamped between the connecting plate 25 and the base 10.

[0032] A downwardly recessed receiving groove 11 is also provided on the upper surface 101 of the base 10. The shape of the receiving groove 11 is consistent with the cross-sectional shape of the high-voltage plug 30. The portion of the high-voltage plug 30 that passes through the through hole 23 is embedded in the receiving groove 11. The receiving groove 11 is arranged opposite to the plug-in hole 23. The portions of the high-voltage plug 30 located at both ends of the chamber 203 are respectively limited by the receiving groove 11 and the plug-in hole 23, so that the high-voltage plug 23 can maintain a high coaxiality with the shell 20, so that the gap between the outer peripheral surface of the high-voltage plug 23 and the inner wall surface of the side wall 21 is consistent in the axial direction of the shell 20. A blind hole 12 extending downward is provided on the bottom surface of the receiving groove 11, and the male connector 31 on the high-voltage plug 30 is inserted downward into the blind hole 12, and the terminal is located in the blind hole 12. Therefore, after the male connector 31 is inserted into the blind hole 12, it can contact and conduct with the terminal. The terminal can be set to be cylindrical with an open top. When the male connector 31 is inserted into the blind hole 12, the male connector 31 can be inserted into the terminal to contact and conduct with the terminal. Of course, the terminal can also be set to be an elastic sheet structure placed at the bottom of the blind hole 12. When the male connector 31 is inserted into the blind hole 12, the terminal is squeezed downward to achieve contact and conduction.

[0033] Generally speaking, four terminals are arranged on the base 10, and correspondingly, four male plugs 31 are arranged on the high-voltage plug 30, and the four male plugs 31 are in contact with and connected to the four terminals one by one, and four blind holes 12 may be arranged on the base 10, and the four terminals are respectively placed in the four blind holes 12. Of course, in other embodiments, the number of the terminals and the male plugs 31 may also be three or more than four.

[0034] The air valve 40 can be directly connected to the shell 20. Specifically, one end interface of the air valve 40 can be directly connected to the side wall 21. However, in order to consider the convenience of installation and air tightness, the present invention fixes a quick-connect flange 50 on the outer surface of the side wall 21 of the shell 20, and the air valve 40 is fixed on the quick-connect flange 50. The surface where the air valve 40 and the quick-connect flange 50 are connected is tightly matched. Specifically, the two can be fixed by bolts, and a sealing gasket is arranged between the surfaces where the two are connected. The nuts on the bolts are tightened to tighten the air valve 40 and the quick-connect flange 50 to clamp the sealing gasket. Of course, the fixing and sealing of the air valve 40 and the quick-connect flange 50 can also adopt the same structure as the connecting plate 25 and the base 10, which will not be repeated here.

[0035] It should be emphasized that the fixing of the air valve 40 and the quick-connect flange 50, and the fixing of the connecting plate 25 and the base 10 are not limited to the fixing method using bolts, and they can also be fixed by gluing, or fixing by clamps.

[0036] In the present invention, since the high-voltage plug is placed in the inner cavity of the shell, the inner cavity where the high-voltage plug is located can be formed into a vacuum environment through the gas valve, or the inner cavity can be filled with insulating gas through the gas valve so that the inner cavity where the high-voltage plug is located is filled with insulating gas, thereby insulating and packaging the high-voltage plug in an airtight manner, which has good sealing effect, good insulation performance, and is easy to install, and has the advantages of convenient transportation and easy operation. With better sealing and insulation performance, it is suitable for the insulation structure of the high-voltage plug of the high-voltage field emission electron gun, and effectively prevents negative phenomena caused by high voltage such as electrical breakdown and creepage.

[0037] The electron gun of the present invention includes the above-mentioned sealing structure of the electron gun high-voltage plug. The other structures of the electron gun are the same as those in the prior art and will not be described in detail here.

[0038] The above description is only a preferred embodiment of the present invention, which is a further detailed description of the present invention in combination with a specific preferred embodiment, and the specific implementation of the present invention cannot be considered to be limited to these descriptions. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. The sealing structure of the electron gun high voltage plug is characterized in that: It includes a base, a shell, a high-pressure plug, and a gas valve; The base is provided with terminals; The shell is a hollow structure, which includes a first end connected to the upper surface of the base and a second end opposite to the first end, the first end is provided with a through hole extending from the inner cavity of the shell to the outer surface of the first end, and the second end is provided with a plug hole extending from the inner cavity of the shell to the outer surface of the second end; the high-voltage plug is inserted into the plug hole and passes through the through hole, and the end of the plug that passes through the through hole is provided with a male plug that contacts and is electrically connected with the terminal; The first end of the shell is tightly matched with the base, and the outer peripheral surface of the high-voltage plug is tightly matched with the inner wall surface of the plug hole; The gas valve is installed outside the shell and communicated with the inner cavity of the shell. The gas valve is used to close the inner cavity of the shell when the inner cavity of the shell is in a vacuum state or when the inner cavity of the shell is filled with insulating gas.

2. The sealing structure of the electron gun high voltage plug according to claim 1, characterized in that: The shell includes a cylindrical side wall and an end wall located at the second end and extending radially inward from the inner side of the side wall along the shell. The plug hole is opened on the end wall, and the through hole is surrounded by the part extending from the side wall to the first end.

3. The sealing structure of the electron gun high voltage plug according to claim 2, characterized in that: The thickness of the end wall is h, where h is greater than or equal to 8 mm; the inner wall surface of the plug hole is provided with a first groove extending along its circumference, the outer circumferential surface of the high-voltage plug is provided with a second groove extending along its circumference, and a first annular seal is provided between the outer circumferential surface of the high-voltage plug and the inner wall surface of the plug hole, and a part of the first annular seal is embedded in the first groove and the other part is embedded in the second groove.

4. The sealing structure of the electron gun high voltage plug according to claim 2, characterized in that: The inner wall surface of the plug hole is offset by a distance d toward the central axis of the shell relative to the inner side surface of the side wall, wherein d≥6mm.

5. The sealing structure of the electron gun high voltage plug according to claim 2, characterized in that: The first end of the shell is provided with a connection disk extending radially outward from the outer side surface of the side wall along the shell, and the connection disk is close to the upper surface of the base.

6. The sealing structure of the electron gun high voltage plug according to claim 5, characterized in that: The upper surface of the base is provided with an annular third groove, the lower surface of the connecting disk is provided with an annular fourth groove, and a second annular seal is provided between the base and the connecting disk, with one part embedded in the third groove and the other part embedded in the fourth groove.

7. The sealing structure of the electron gun high voltage plug according to claim 6, characterized in that: The base and the connecting plate are fixed together by a plurality of locking bolts which cross the two.

8. The sealing structure of the electron gun high voltage plug according to claim 1, characterized in that: The upper surface of the base is recessed downward to form a receiving groove, which is arranged opposite to the plug hole. The part of the high-voltage plug passing through the through hole is embedded in the receiving groove. The bottom surface of the receiving groove is provided with a blind hole extending downward for the male plug to penetrate, and the terminal is placed in the blind hole.

9. The sealing structure of the electron gun high voltage plug according to claim 1, characterized in that: A quick-connect flange is fixedly connected to the shell body, the gas valve is fixed on the quick-connect flange, and the mutually butted surfaces of the gas valve and the quick-connect flange are tightly matched.

10. An electron gun, characterized in that A sealing structure comprising a high-voltage plug of an electron gun as claimed in any one of claims 1 to 9.

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