A CVD coating conformal tooling for a flow guide tube

Abstract

This application provides a CVD coating conformal fixture for a guide tube, relating to the field of chemical vapor deposition coating technology. The fixture includes a base diffuser plate for supporting the guide tube, with a first side panel below the base diffuser plate. An inner wall muffler is installed on the base diffuser plate and inserted into the guide tube. A second side panel is installed on the base diffuser plate outside the guide tube, with an air inlet between the inner wall muffler and the second side panel. An outer wall baffle plate is installed above the second side panel, with clearance holes for accommodating the guide tube. An outer wall step bracket is installed within the clearance holes of the outer wall baffle plate. An outer wall muffler is installed on the outer wall step bracket or the outer wall baffle plate, with a top diffuser plate on top of the outer wall muffler and an air outlet hole. This fixture not only improves coating uniformity but also offers advantages such as convenient loading and unloading and adaptability to guide tubes of different specifications.

Description

Technical Field

[0001] This utility model relates to the field of chemical vapor deposition coating technology, specifically a CVD coating conformal tooling for a flow guide tube. Background Technology

[0002] Chemical vapor deposition (CVD), as a cutting-edge material surface treatment technology, uses gaseous reactants to undergo chemical reactions under specific conditions, thereby endowing the surface of materials with unique functional properties while maintaining the original composition and mechanical properties of the substrate. This technology, with its excellent process characteristics, can prepare a variety of coating materials such as pyrolytic carbon (PyC), silicon carbide (SiC), tantalum carbide (TaC), and boron nitride (BN). These coating materials, due to their superior performance, have been widely used in many key fields.

[0003] In the CVD (Chemical Vapor Deposition) coating production process using a flow guide tube, the structural design of the tooling plays a decisive role in coating uniformity, process stability, and production costs. This process requires the tooling materials to withstand the high-temperature reaction environment while possessing good gas conductivity and chemical stability. Currently, traditional CVD tooling mostly adopts an integral structure, using metal or graphite as the main material. While this can meet basic process requirements, the following key problems have gradually emerged in practical applications:

[0004] First, during chemical vapor deposition (CVD) operations, the entire furnace chamber is filled with process gases. As the number of furnace cycles increases, a coating will also be deposited on the surface of the tooling. Furthermore, the tooling will deform during repeated heating and cooling processes. Therefore, after a certain number of furnace cycles, it is necessary to correct the deformation and remove the coating deposited on the surface. However, traditional tooling has an integral structure, which not only makes it difficult to correct deformation but also makes it inconvenient to clean the coating adhering to it.

[0005] Secondly, the operating costs remain high. Integrated tooling has a complex structure and uses a large amount of material. If wear, corrosion, or cracking occurs in any part, the entire tooling must be replaced, leading to significant material waste. In large-scale industrial production, frequent tooling replacements not only increase procurement costs but also require downtime for adjustments, significantly reducing production efficiency. Furthermore, the high customization costs of traditional integrated tooling make it difficult to adapt to the flexible production needs of multiple batches and small quantities, further increasing the average cost per unit. Summary of the Invention

[0006] To address the aforementioned issues, this application provides a CVD coating conformal tooling for a guide tube that not only improves the uniformity of the coating but also offers advantages such as convenient loading and unloading and adaptability to guide tubes of different specifications.

[0007] The technical solution adopted by this utility model to solve its technical problem is:

[0008] A CVD coating conformal tooling for a flow guide tube includes a base air diffuser plate, with the flow guide tube placed on the base air diffuser plate and the outer flange of the flow guide tube facing downwards.

[0009] A first side panel is provided below the base air diffuser plate;

[0010] The base diffuser plate is provided with an inner wall muffler, and the inner wall muffler is inserted into the guide tube;

[0011] The base air diffuser plate is provided with a second side panel on the outside of the guide tube, and multiple air inlets are evenly distributed on the base air diffuser plate between the inner wall muffle and the second side panel.

[0012] An outer wall air barrier plate is provided above the second side panel, and the outer wall air barrier plate is provided with clearance holes for accommodating the guide tube.

[0013] An outer wall step frame is provided in the clearance hole of the outer wall air barrier plate;

[0014] The outer wall step frame includes a flange plate, and a guide plate is provided on the lower side of the flange plate. The guide plate is inserted downward into the clearance hole, and the lower end of the guide plate extends to the bottom of the outer wall air barrier plate.

[0015] The outer wall step frame or outer wall air barrier plate is provided with an outer wall muffler, and the top of the outer wall muffler is provided with a top air diffuser plate, and the top air diffuser plate is provided with an air outlet.

[0016] Furthermore, an inner wall top plate is provided on the top of the inner wall muffle.

[0017] Furthermore, the inner wall top plate is provided with several through holes.

[0018] Furthermore, the diameter of the clearance hole is larger than the outer diameter of the guide plate.

[0019] Furthermore, the diameter of the clearance hole is 1mm-5mm larger than the outer diameter of the guide plate.

[0020] Furthermore, the air outlet includes a first air outlet and a plurality of second air outlets, wherein the first air outlet is located in the middle of the top air diffuser plate, and the plurality of second air outlets are arranged along the edge of the top air diffuser plate.

[0021] Furthermore, the base diffuser plate is provided with a number of support pins for supporting the guide tube.

[0022] Furthermore, nine support nails are evenly distributed around the center of the base air diffuser plate along the circumferential direction.

[0023] Furthermore, the support pin has a conical or triangular prism structure.

[0024] The beneficial effects of this utility model are:

[0025] 1. The CVD coating conformal tooling for a guide tube provided in this application adopts a splicing structure and has a diffuser plate inside for placing the guide tube and dispersing exhaust. This not only reduces the manufacturing and use cost of the tooling, but also improves the flexibility of the tooling for coating deposition on the guide tube product. In actual work, appropriate parts can be selected for assembly according to the specifications of the guide tube. It has good adaptability and versatility and can meet the flexible production needs of multiple batches and small quantities.

[0026] 2. The present application provides a CVD coating conformal tooling for a guide tube with a spliced ​​structure. On the one hand, it increases the deformation space and can absorb more deformation, thereby reducing the final deformation range of the tooling; on the other hand, the split structure can easily correct deformation and remove the coating deposited on the surface. Attached Figure Description

[0027] Figure 1 A three-dimensional structural schematic diagram of a CVD coating conformal tooling for a flow guide tube provided in an embodiment of this application;

[0028] Figure 2 A front view of a CVD coating contouring tooling for a flow guide tube provided in one embodiment of this application;

[0029] Figure 3 for Figure 2 AA section view in the middle;

[0030] Figure 4 for Figure 3 A magnified structural diagram of part A in the middle;

[0031] Figure 5 for Figure 3 A magnified structural diagram of part B in the middle section;

[0032] Figure 6 for Figure 3 A magnified structural diagram of section C;

[0033] Figure 7 An exploded view of a CVD coating conformal tooling for a flow guide tube provided in one embodiment of this application;

[0034] Figure 8 for Figure 7 A magnified structural diagram of section D;

[0035] Figure 9A cross-sectional view of a CVD coating conformal tooling for a flow guide tube provided in another embodiment of this application.

[0036] In the diagram: 101, base diffuser plate; 1011, air inlet; 102, first side panel; 103, inner wall muffler; 104, second side panel; 105, outer wall baffle plate; 1051, clearance hole; 106, outer wall step frame; 1061, flange plate; 1062, guide plate; 107, outer wall muffler; 108, top diffuser plate; 1081, first air outlet; 1082, second air outlet; 109, inner wall top plate; 1091, through hole; 110, support pin;

[0037] 2. Flow guide tube; 21. Outward flange. Detailed Implementation

[0038] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be described in detail below with reference to the accompanying drawings. The described embodiments are merely a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort should fall within the protection scope of this application.

[0039] To facilitate understanding of the specific embodiments of this application, a coordinate system is now defined as follows: Figure 1 As shown, the left and right directions are horizontal, the front and back directions are vertical, and the up and down directions are vertical.

[0040] Example 1

[0041] like Figure 1 , Figure 2 , Figure 3 and Figure 7 As shown, a CVD coating conformal fixture for a flow guide tube includes a circular base diffuser plate 101. The flow guide tube 2 to be coated by chemical vapor deposition is placed on the base diffuser plate 101, with the outer flange 21 of the flow guide tube 2 facing downward. A first side panel 102 for supporting the base diffuser plate 101 is provided below the base diffuser plate 101.

[0042] In one specific embodiment, the first side panel 102 in this embodiment has a cylindrical structure. The outer diameter of the first side panel 102 is equal to the diameter of the base air diffuser plate 101, and the first side panel 102 and the base air diffuser plate 101 are arranged coaxially. The cylindrical side surface of the base air diffuser plate 101 and the outer side surface of the first side panel 102 form a complete cylindrical surface.

[0043] The upper side of the base air diffuser plate 101 is provided with an inner wall muffle 103 in the form of a cylindrical structure. The inner wall muffle 103 is coaxially arranged with the base air diffuser plate 101 and is inserted into the guide tube 2 from bottom to top.

[0044] A second side panel 104 with a cylindrical structure is provided on the outer side of the outer flange 21 of the guide tube 2 on the base air diffuser plate 101, and the second side panel 104 is coaxially arranged with the base air diffuser plate 101. Multiple air inlets 1011 are evenly distributed on the base air diffuser plate 101 between the inner wall muffle 103 and the second side panel 104.

[0045] In one specific embodiment, the base air diffuser plate 101 described in this embodiment is evenly distributed with air inlet holes 1011 located between the inner wall muffle 103 and the second side panel 104.

[0046] A circular outer wall baffle plate 105 is provided above the second side panel 104. The outer wall baffle plate 105 is coaxially arranged with the second side panel 104, and the outer end of the outer wall baffle plate 105 (the side radially away from the center is the outer side) overlaps the upper end surface of the second side panel 104. A clearance hole 1051 for accommodating the guide tube 2 is provided in the middle of the outer wall baffle plate 105, and the upper end of the guide tube 2 extends through the clearance hole 1051 to the upper side of the outer wall baffle plate 105.

[0047] An outer wall step bracket 106 is provided within the clearance hole 1051 of the outer wall air barrier plate 105. The outer wall step bracket 106 includes a flange plate 1061 with a circular structure. A guide plate 1062 with a cylindrical structure is provided on the lower side of the flange plate 1061, and the guide plate 1062 is coaxially arranged with the flange plate 1061. The guide plate 1062 is inserted downward into the clearance hole 1051, and the lower end of the guide plate 1062 extends below the outer wall air barrier plate 105 (i.e., the lower end face of the guide plate 1062 is located below the lower side of the outer wall air barrier plate 105), thereby forming a downwardly extending annular protrusion on the lower side of the outer wall air barrier plate 105. The flange plate 1061 is pressed against the upper side of the outer wall air barrier plate 105 under the weight of the outer wall step frame 106, and the flange plate 1061 and the outer wall air barrier plate 105 are arranged coaxially.

[0048] In one specific embodiment, the inner diameter of the guide plate 1062 is equal to the inner diameter of the flange plate 1061, and the inner cylindrical surface of the guide plate 1062 and the inner cylindrical surface of the flange plate 1061 form a complete cylindrical surface, which is the inner cylindrical surface of the outer wall step frame 106.

[0049] The outer wall step frame 106 is provided with an outer wall muffle 107 with a cylindrical structure. The outer wall muffle 107 is coaxially arranged with the base diffuser plate 101, and the upper end of the outer wall muffle 107 extends above the guide tube 2. The top of the outer wall muffle 107 is provided with a top diffuser plate 108, and the top diffuser plate 108 is provided with air outlet holes.

[0050] The flow guide tube 2 is located within the contoured cavity formed by the bottom diffuser plate, the second side panel 104, the outer wall baffle plate 105, the outer wall step frame 106, the outer wall muffle 107, the top diffuser plate 108, and the inner wall muffle 103, and the contoured cavity is divided into an outer cavity and an inner cavity by the flow guide tube 2. The outer cavity is located on the outside of the flow guide tube 2, and when the process gas flows through the outer cavity, a coating can be deposited on the outer surface of the flow guide tube 2; the inner cavity is located on the inside of the flow guide tube 2, and when the process gas flows through the inner cavity, a coating can be deposited on the inner surface of the flow guide tube 2.

[0051] In one specific embodiment, the inner diameter of the outer wall muffle 107 is equal to the diameter of the inner cylindrical surface of the outer wall step frame 106, and the inner cylindrical surface of the outer wall muffle 107 and the inner cylindrical surface of the outer wall step frame 106 form a complete cylindrical surface.

[0052] By setting an outer wall step frame 106 and extending the guide plate 1062 of the outer wall step frame 106 below the outer wall gas barrier plate 105, when the process gas enters the outer cavity from the gas diffuser hole, it can form a downward flow trend under the blocking and guiding effect of the guide plate 1062, thereby avoiding the problem of insufficient deposition of coating on the back of the outer flange 21 of the guide tube 2 due to the process gas flowing directly upward along the outer cavity.

[0053] Furthermore, 3. Figure 6 and Figure 7 As shown, an inner wall top plate 109 is provided on the top of the inner wall muffle 103.

[0054] By setting the inner wall top plate 109, it is possible to avoid the formation of turbulence or eddies of process gas at the upper opening of the inner wall muffle 103, which would result in uneven coating thickness at the upper end of the inner side of the guide tube 2.

[0055] Furthermore, the inner wall top plate 109 is provided with a plurality of through holes 1091 for balancing pressure.

[0056] The reason for providing through holes 1091 on the inner wall top plate 109 is that, in actual operation, a negative pressure device is needed to evacuate the entire furnace cavity, thereby creating a certain negative pressure state throughout the furnace cavity. This allows the process gas to flow more evenly. By providing through holes 1091, the space formed by the inner wall muffle 103, the inner wall top plate 109, and the base diffuser plate 101 can be connected with the external space, which is also under a certain negative pressure state. This ensures consistent pressure and prevents the inner wall muffle 103, the inner wall top plate 109, and the base diffuser plate 101 from deforming under pressure.

[0057] In one specific embodiment, the inner wall top plate 109 described in this embodiment is provided with three through holes 1091, and the three through holes 1091 are evenly arranged around the center of the inner wall top plate 109 in the circumferential direction.

[0058] Furthermore, such as Figure 3 and Figure 5 As shown, the diameter of the clearance hole 1051 on the side wall air barrier is larger than the outer diameter of the guide plate 1062 of the outer wall step frame 106. An expansion joint with a width of M is formed between the side wall air barrier and the guide plate 1062 of the outer wall step frame 106. Preferably, the width M of the expansion joint is 1mm-5mm. By setting the expansion joint, excessive local thermal stress caused by uneven thermal expansion between different parts of the tooling can be prevented from damaging the tooling, thus improving the structural stability of the tooling during application and reducing the risk of tooling structural failure.

[0059] Furthermore, such as Figure 1 As shown, the air outlets provided on the top air diffuser plate 108 include a first air outlet 1081 and a plurality of second air outlets 1082. The first air outlet 1081 is located in the middle of the top air diffuser plate 108 and is arranged coaxially with the top air diffuser plate 108. The plurality of second air outlets 1082 are located at the edge of the top air diffuser plate 108 and are evenly arranged circumferentially around the center of the top air diffuser plate 108.

[0060] like Figure 3As shown, during operation, when the process gas enters through the diffuser hole, part of it flows upward along the outer cavity, and the other part flows upward along the inner cavity. The process gas flowing upward along the outer cavity deposits a coating on the outer surface of the guide tube 2, and most of the process gas flowing along the outer cavity eventually flows out through the second vent hole 1082; the process gas flowing upward along the inner cavity deposits a coating on the inner surface of the guide tube 2, and most of the process gas flowing along the inner cavity eventually flows out through the first vent hole. By setting vent holes at corresponding positions in the inner and outer cavities, collisions and turbulence can be avoided when the process gas passing through the inner and outer cavities converge at the top, thus preventing any impact on the uniformity of the coating.

[0061] Furthermore, such as Figure 3 , Figure 4 and Figure 8 As shown, a plurality of support pins 110 are evenly distributed around the center of the base diffuser plate 101 along the circumferential direction. The lower end of the support pin 110 abuts against the base diffuser plate 101, and the upper end of the support pin 110 abuts against the outer flange 21 of the guide tube 2. By setting the support pins 110, the outer flange 21 of the guide tube 2 can be prevented from directly contacting the base diffuser plate 101: on the one hand, it can improve the coating uniformity on the front side of the outer flange 21 of the guide tube 2; on the other hand, after the CVD process, the unreacted deposited raw materials and by-products (such as silicides and carbides) will solidify and adhere to the bottom of the tooling, forming a hard residue layer that is difficult to remove. These residues not only interfere with the precise positioning of the guide tube 2 in subsequent batches, causing deviations in the flow path of the process gas and resulting in defects such as uneven coating thickness, excessive local thickness, or incomplete coating, but also, due to the significant difference in the thermal expansion coefficients between the tooling material and the residues, they are prone to cracking of the bottom surface of the tooling during repeated heating and cooling processes, affecting the stability of coating deposition and the service life of the tooling. By setting the support pin 110, the contact area between the support pin 110 and the outer flange 21 of the guide tube 2 can be reduced, avoiding the difficulty in separating the guide tube 2 from the support pin due to adhesion after the process is completed.

[0062] In one specific embodiment, nine support nails 110 are evenly distributed around the center of the base air diffuser plate 101 in the circumferential direction on the base air diffuser plate 101 described in this embodiment.

[0063] The support pin 110 has a conical or triangular prism structure. In one specific embodiment, the support pin 110 in this example has a conical structure with a smaller diameter at the top and a larger diameter at the bottom.

[0064] Furthermore, the support pin 110 is not connected and fixed to the base air diffuser plate 101, but is placed directly on the base air diffuser plate 101. In this way, the position of the support pin 110 can be adjusted according to the specifications and dimensions of the guide tube 2, thereby meeting the needs of different specifications and models of guide tubes 2.

[0065] Example 2

[0066] like Figure 9 As shown, the outer wall baffle plate 105 is provided with an outer wall muffle 107 in the form of a cylindrical structure. The outer wall muffle 107 is coaxially arranged with the base diffuser plate 101, and the upper end of the outer wall muffle 107 extends above the guide tube 2.

[0067] In one specific embodiment, the inner diameter of the outer wall muffle 107 is equal to the outer diameter of the flange plate 1061 of the outer wall step frame 106, the lower end face of the outer wall muffle 107 is in contact with the upper side of the outer wall baffle plate 105, and the inner side of the outer wall muffle 107 is in contact with the outer cylindrical surface of the flange plate 1061.

[0068] The rest of the structure is the same as in Example 1.

[0069] Other embodiments obtained by those skilled in the art based on the embodiments provided in this application by combining, splitting, or reorganizing the embodiments of this application do not exceed the protection scope of this application.

[0070] The above detailed embodiments have provided a detailed explanation of the purpose, technical solutions, and beneficial effects of the embodiments of this application. The above are merely specific embodiments of the embodiments of this application and are not intended to limit the protection scope of the embodiments of this application. That is, any modifications, equivalent substitutions, improvements, etc., made on the basis of the embodiments of this application should be included within the protection scope of the embodiments of this application.

Claims

1. A CVD coating contouring fixture for a flow guide tube, characterized in that: Includes a base air diffuser plate (101), a guide tube (2) is placed on the base air diffuser plate (101), and the outer flange (21) of the guide tube (2) faces downward; A first side panel (102) is provided below the base air diffuser (101). The base diffuser plate (101) is provided with an inner wall muffler (103), and the inner wall muffler (103) is inserted into the guide tube (2); The base air diffuser plate (101) is provided with a second side panel (104) on the outside of the guide tube (2), and a plurality of air inlets (1011) are evenly distributed on the base air diffuser plate (101) between the inner wall muffler (103) and the second side panel (104). An outer wall baffle plate (105) is provided above the second side panel (104), and the outer wall baffle plate (105) is provided with a clearance hole (1051) for accommodating the guide tube (2). An outer wall step frame (106) is provided in the clearance hole (1051) of the outer wall air barrier plate (105). The outer wall step frame (106) includes a flange plate (1061), and a guide plate (1062) is provided on the lower side of the flange plate (1061). The guide plate (1062) is inserted downward into the clearance hole (1051), and the lower end of the guide plate (1062) extends to the bottom of the outer wall air barrier plate (105). An outer wall muffler (107) is provided on the outer wall step frame (106) or the outer wall air barrier plate (105), and a top air diffuser plate (108) is provided on the top of the outer wall muffler (107), and an air outlet is provided on the top air diffuser plate (108).

2. The CVD coating conformal tooling for a guide tube according to claim 1, characterized in that: The top of the inner wall muffle (103) is provided with an inner wall top plate (109).

3. The CVD coating contouring fixture for a guide tube according to claim 2, characterized in that: The inner wall top plate (109) is provided with several through holes (1091).

4. The CVD coating contouring fixture for a guide tube according to claim 1, characterized in that: The diameter of the clearance hole (1051) is larger than the outer diameter of the guide plate (1062).

5. The CVD coating conformal tooling for a guide tube according to claim 4, characterized in that: The diameter of the clearance hole (1051) is 1mm-5mm larger than the outer diameter of the guide plate (1062).

6. The CVD coating contouring fixture for a guide tube according to claim 1, characterized in that: The air outlet includes a first air outlet (1081) and a plurality of second air outlets (1082). The first air outlet (1081) is located in the middle of the top air diffuser plate (108), and the plurality of second air outlets (1082) are arranged along the edge of the top air diffuser plate (108).

7. The CVD coating contouring fixture for a guide tube according to claim 1, characterized in that: The base air diffuser plate (101) is provided with a number of support nails (110) for supporting the guide tube (2).

8. The CVD coating conformal tooling for a guide tube according to claim 7, characterized in that: Nine support nails (110) are evenly distributed around the center of the base air diffuser plate (101) along the circumferential direction.

9. The CVD coating contouring fixture for a guide tube according to claim 7, characterized in that: The support nail (110) has a conical structure or a triangular prism structure.

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