X-ray tube with ceramic plate with special structural design

Abstract

The utility model discloses an X-ray tube with a ceramic plate with a special structural design, which comprises a cathode assembly, an anode assembly, the ceramic plate and a vacuum tube shell, and the ceramic plate is arranged in the vacuum tube shell and between the outer peripheral wall of the cathode assembly and the inner peripheral wall of the vacuum tube shell. The anode assembly, the cathode assembly and the vacuum tube shell are mutually fixed to form a vacuum sealing environment; the ceramic plate is annular, at least two annular cambered surfaces coaxial with the ceramic plate are arranged on the annular surface, facing the anode assembly, of the ceramic plate, and the adjacent annular cambered surfaces are in smooth transition. When the X-ray tube is designed, the plurality of annular cambered surfaces are arranged on the ceramic plate, so that the creepage distance of the ceramic surface is increased, electric arcs can be effectively prevented from forming a path along the ceramic surface, the possibility of surface discharge is reduced, the voltage endurance capability is improved, and meanwhile, the connecting surfaces between the adjacent annular cambered surfaces are required to be in smooth transition, so that the service life of the X-ray tube is prolonged. Therefore, the problem that a large number of charges are gathered at the tip is avoided, and the service life of the product is effectively ensured.

Description

Technical Field

[0001] This utility model belongs to the field of X-ray tube technology, and in particular relates to an X-ray tube with a ceramic plate having a special structural design. Background Technology

[0002] A X-ray tube is a high-voltage vacuum device that generates X-rays. It mainly consists of a cathode assembly, an anode assembly, and a vacuum-sealed shell. The cathode and anode are supported by a stainless steel shell, the cathode assembly is insulated from the metal shell by ceramic, and the anode assembly is directly welded to the metal shell. When the X-ray tube is working, a low voltage is applied across the cathode filament. When the filament heats up to a certain temperature, electrons in the filament gain enough energy to overcome the binding force of the metal surface and escape. A high voltage is applied between the cathode and anode of the X-ray tube, and the electrons emitted from the cathode are accelerated under the influence of the electric field.

[0003] Ceramic, used as the tube shell and cathode support, has excellent insulation properties, effectively preventing high-voltage electric fields from leaking to the outside and avoiding current discharge through the tube shell. It ensures that electrons only accelerate from the cathode through the vacuum region to bombard the anode, forming a directional electron beam, enabling the X-ray tube to function normally. Currently, the ceramic components commonly found on the market are usually flat. Early researchers typically improved the pressure resistance of X-ray tube ceramics by increasing their length. However, as the ceramic length increases, the improvement in pressure resistance eventually tends to saturate, resulting in a lower average electric field intensity on the ceramic surface in practical applications. Therefore, a new solution is needed to improve or solve the above problems. Utility Model Content

[0004] The purpose of this invention is to provide an X-ray tube with a ceramic plate having a special structural design, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: an X-ray tube with a ceramic plate having a special structural design, comprising a cathode assembly, an anode assembly, a ceramic plate, and a vacuum tube shell. The cathode assembly and the anode assembly are respectively disposed at both ends of the vacuum tube shell. One end of the cathode assembly extends into the vacuum tube shell. The ceramic plate is placed inside the vacuum tube shell and is disposed between the outer peripheral wall of the cathode assembly and the inner peripheral wall of the vacuum tube shell to cooperate with the anode assembly to form a vacuum-sealed environment.

[0006] The ceramic plate is annular, and at least two annular arc surfaces coaxial with the ceramic plate are formed on the annular surface facing the anode assembly. The adjacent annular arc surfaces are smoothly transitioned, and the annular arc surfaces are smoothly transitioned to the annular surface they are located on.

[0007] Preferably, the inner ring wall of the ceramic plate is sleeved on the cathode assembly, and the outer ring wall of the ceramic plate is attached to the vacuum tube shell. A first incised surface is connected between the annular surface of the ceramic plate facing the anode assembly and its outer ring wall, and a second incised surface is connected between the annular surface of the ceramic plate facing the anode assembly and its inner ring wall. The outer ring wall, the first incised surface, and the annular surface have a smooth transition, and the inner ring wall, the second incised surface, and the annular surface have a smooth transition.

[0008] Preferably, the annular arc surface, the smooth transition surface between the annular arc surfaces, the first inclined surface, the second inclined surface, the smooth transition surface between the first inclined surface and the outer ring wall and the annular surface, and the smooth transition surface between the second inclined surface and the inner ring wall and the annular surface are all coated with a voltage-resistant coating.

[0009] Preferably, a metal layer is fixed on both the inner and outer ring walls of the ceramic plate.

[0010] Preferably, the ceramic plate is made of 96% Al2O3 ceramic.

[0011] Preferably, the width-to-depth ratio x:y of the annular arc surface is 6:(1-2).

[0012] Preferably, the total length of the smooth transition surfaces between the first inclined plane, the annular arc surface, the second inclined plane, and the three, as well as the smooth transition surfaces between the first inclined plane and the outer ring wall and the second inclined plane and the inner ring wall, is set as a, and the ratio between the diameter d of the inner ring of the ceramic plate and a is in the range of 3:(4-5).

[0013] The beneficial effects of this utility model are as follows: In the design of the X-ray tube of this solution, multiple annular arc surfaces are opened on the ceramic plate, which increases the creepage distance of the ceramic surface. This can effectively prevent the electric arc from forming a path along the ceramic surface, reduce the possibility of surface discharge, and thus improve the withstand voltage. At the same time, the connection surface between adjacent annular arc surfaces is required to be smooth to prevent the problem of charge from accumulating in large quantities at the tip, thus effectively ensuring the service life of the product.

[0014] By setting up incised surface one, incised surface two, and ensuring a smooth transition between the ceramic plate and the parts connected to incised surface one and incised surface two, the creepage distance on the ceramic surface can be further increased. At the same time, this design scheme will also avoid the problem of a large amount of charge accumulating at the tip.

[0015] Among them, by coating a voltage-resistant coating

[0016] By fixing metal layers to the inner and outer ring walls of the ceramic plate, the bonding force between the ceramic plate and the cathode component and vacuum tube shell can be increased, making the ceramic plate more stable in the X-ray tube. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model;

[0018] Figure 2 This is a schematic diagram of the structure of the ceramic plate in this utility model;

[0019] Figure 3 This is a schematic diagram simulating the electric field of the ceramic plate in this utility model;

[0020] Figure 4 This is a schematic diagram of the electric field mode of a flat ceramic plate in the prior art;

[0021] In the figure: 1. Electrode post; 2. Ceramic plate; 21. Annular arc surface; 22. Outer ring wall; 23. Inclined surface one; 24. Inner ring wall; 25. Inclined surface two; 3. Cathode assembly; 4. Vacuum tube shell; 5. Anode target; 6. Anode cylinder. Detailed Implementation

[0022] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the scope of protection of the present invention.

[0023] Example:

[0024] See Figure 1-2 An X-ray tube with a specially designed ceramic plate is provided. The X-ray tube includes a cathode assembly 3, an anode assembly, a ceramic plate 2, and a vacuum tube shell 4. The cathode assembly and the anode assembly are respectively disposed at both ends of the vacuum tube shell. One end of the cathode assembly extends into the vacuum tube shell. The ceramic plate is placed inside the vacuum tube shell and is disposed between the outer peripheral wall of the cathode assembly and the inner peripheral wall of the vacuum tube shell, so that it is fixed to the cathode assembly and the vacuum tube shell to cooperate with the anode assembly to form a vacuum-sealed environment.

[0025] An electrode is fixed to the cathode assembly via an electrode post 1. The cathode assembly emits an electron beam, which is accelerated by an internal high voltage and directed towards the X-ray tube anode assembly. The anode assembly includes an anode cylinder 5 and an anode target 6. The anode target interacts with the high-speed electron beam generated by the cathode assembly, producing X-rays. The vacuum tube shell provides mechanical support and structural stability protection, and forms a vacuum-sealed environment with the anode assembly, cathode assembly, and ceramic plate. The ceramic plate has high resistivity to effectively isolate the high-voltage electrodes (cathode assembly and anode assembly) and prevent high-voltage breakdown.

[0026] The ceramic plate is annular, and at least two annular arc surfaces 21 coaxial with the ceramic plate are formed on the annular surface (not marked) facing the anode assembly. The adjacent annular arc surfaces are smoothly transitioned, and the annular arc surfaces are smoothly transitioned to the annular surface they are located on.

[0027] The inner ring wall of the ceramic plate is fitted onto the cathode assembly, and the outer ring wall of the ceramic plate is attached to the vacuum tube shell. A chamfered surface 23 is connected between the annular surface of the ceramic plate facing the anode assembly and its outer ring wall 22, and a chamfered surface 25 is connected between the annular surface of the ceramic plate facing the anode assembly and its inner ring wall 24. The outer ring wall, the chamfered surface 1, and the annular surface have a smooth transition, and the inner ring wall, the chamfered surface 2, and the annular surface have a smooth transition.

[0028] The annular arc surface, the smooth transition surface between the annular arc surfaces, the first inclined surface, the second inclined surface, the smooth transition surface between the first inclined surface and the outer ring wall and the annular surface, and the smooth transition surface between the second inclined surface and the inner ring wall and the annular surface are all coated with a voltage-resistant coating.

[0029] The ceramic plate has metal layers fixed on both its inner and outer ring walls.

[0030] The ceramic plate is made of 96% Al2O3 ceramic.

[0031] The width-to-depth ratio x:y of the annular arc surface is 6:(1-2).

[0032] The total length of the smooth transition surfaces between the first inclined plane, the annular arc surface, the second inclined plane, and the three inclined planes, as well as the smooth transition surfaces between the first inclined plane and the outer ring wall, and between the second inclined plane and the inner ring wall, is defined as 'a'. The ratio between the diameter 'd' of the inner ring of the ceramic plate and 'a' is 3:(4-5). (See reference...) Figure 3 'a' represents the path shown by the red line.

[0033] See Figure 4 , Figure 4 The diagram shows an electric field simulation of an existing flat ceramic plate. It illustrates that during use, the electric field on the flat ceramic plate exhibits a clear stratification in its left-right distribution, with a significant difference in field strength between the two main layers (the low value in the dark blue part on the left is 1.0E+6, while the low value in the light blue part on the right is between 5.0E+6 and 9.0E+6, with the difference at the boundary between the two parts ranging from 4.0E+6 to 8.0E+6). This makes continuous discharge prone to occur at the boundary during use, rendering the product unsuitable for high-voltage environments.

[0034] In contrast, see Figure 3 , Figure 3The electric field simulation diagram of this application is shown. In the electric field simulation diagram of this application, the electric field distribution on the ceramic plate shows an increase or decrease within a small range, and the range of increase or decrease is not large (the difference at the boundary of adjacent electric field changes is about 1.5E+6). It can be seen that the electric field change trend of this application is a small and stable change during use, which effectively suppresses the occurrence of discharge. This allows the X-ray tube designed in this application to be used in higher voltage environments compared to flat ceramic plates, thus improving the application range of the product. In the actual design process, the applicant found that research showed that by designing the width-to-depth ratio of the annular arc surface to be between 6: (1-2) and the ratio between the diameter d and a of the inner ring of the ceramic plate to be between 3: (4-5), the change amplitude of the electric field can maintain a better small change state, effectively ensuring the product's usage requirements.

[0035] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. An X-ray tube having a ceramic plate with a special structural design, characterized in that: The assembly includes a cathode assembly (3), an anode assembly, a ceramic plate (2), and a vacuum tube shell (4). The cathode assembly (3) and the anode assembly are respectively disposed at both ends of the vacuum tube shell (4). One end of the cathode assembly extends into the vacuum tube shell. The ceramic plate (2) is placed inside the vacuum tube shell and is disposed between the outer peripheral wall of the cathode assembly (3) and the inner peripheral wall of the vacuum tube shell, so that it is fixed to the cathode assembly and the vacuum tube shell to cooperate with the anode assembly to form a vacuum sealed environment. The ceramic plate (2) is annular, and at least two annular arc surfaces (21) coaxial with the ceramic plate are opened on the annular surface facing the anode assembly. The adjacent annular arc surfaces are smoothly transitioned, and the annular arc surfaces are smoothly transitioned with the annular surface they are located on.

2. The X-ray tube with a ceramic plate of special structural design according to claim 1, characterized in that: The inner ring wall (24) of the ceramic plate (2) is fitted onto the cathode assembly, and the outer ring wall (22) of the ceramic plate is attached to the vacuum tube shell. A chamfered surface (23) is connected between the annular surface of the ceramic plate facing the anode assembly and its outer ring wall (22), and a chamfered surface (25) is connected between the annular surface of the ceramic plate facing the anode assembly and its inner ring wall (24). The outer ring wall (22), the chamfered surface (23) and the annular surface are smoothly connected, and the inner ring wall (24), the chamfered surface (25) and the annular surface are also smoothly connected.

3. The X-ray tube with a ceramic plate of special structural design according to claim 2, characterized in that: The annular arc surface (21), the smooth transition surface between the annular arc surface (21), the first inverted surface (23), the second inverted surface (25), the smooth transition surface between the first inverted surface (23) and the outer ring wall (22) and the annular surface, and the smooth transition surface between the second inverted surface (25) and the inner ring wall (24) and the annular surface are all coated with a voltage-resistant coating.

4. The X-ray tube with a ceramic plate of special structural design according to claim 2, characterized in that: Metal layers are fixed on both the inner and outer ring walls of the ceramic plate.

5. The X-ray tube with a ceramic plate of special structural design according to claim 4, characterized in that: The ceramic plate is made of 96% Al2O3 ceramic.

6. The X-ray tube with a ceramic plate of special structural design according to claim 1, characterized in that: The width-to-depth ratio x:y of the annular arc surface is 6:(1-2).

7. The X-ray tube with a ceramic plate of special structural design according to claim 2, characterized in that: Let a be the total length of the smooth transition surfaces between the first inclined plane, the annular arc surface, the second inclined plane, and the three, as well as the smooth transition surfaces between the first inclined plane and the outer ring wall and the second inclined plane and the inner ring wall. The ratio between the diameter d of the inner ring of the ceramic plate and a is 3:(4-5).

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