Forming method for a carbon fiber wound pressure vessel with an opening on the head

Abstract

The present invention provides a carbon fiber wound pressure vessel with an opening in the head and a forming method thereof, belonging to the technical field of carbon fiber composite material forming. The problem of the internal pressure strength and sealing of the carbon fiber wound pressure vessel after an opening is made in the vessel head is solved. It includes a joint metal part, a head opening metal part, a lining repair layer, a lining layer, and a fiber winding structure layer. The joint metal part includes a metal joint and an opening metal part. The metal joint and the opening metal part are arranged at the left and right ends of the pressure vessel. The head opening metal part is arranged on one side of the metal joint of the pressure vessel. A lining repair layer is provided on the outer side of the connection part between the head opening metal part and the pressure vessel. The inner surface of the pressure vessel is the lining layer, and the outer surface of the pressure vessel is the fiber winding structure layer. It is mainly used for the forming of the carbon fiber wound pressure vessel.

Description

Technical Field

[0001] The present invention belongs to the technical field of carbon fiber composite material forming, and particularly relates to a forming method for a carbon fiber wound pressure vessel with an opening in the head. Background Art

[0002] As a new type of structural material, carbon fiber has a strength more than 7 to 8 times that of ordinary steel materials and is known as the king of emerging materials. Carbon fiber wound composites have many advantages such as light weight and high strength, and structural designability, and are widely used in industrial manufacturing fields such as high-pressure vessels and aerospace solid rocket motor casings. The continuity of the fibers in the carbon fiber structure layer is the key to ensuring strength. Opening a hole in the head of a fiber wound container will destroy the continuity of the fiber in the container head structure layer, greatly reduce the burst strength of the container, and at the same time cause damage to the sealing of the inner liner. Before the strength and sealing of the head are solved, the design of carbon fiber high-pressure vessels avoids opening holes in the container head, which severely restricts the wide application of carbon fiber high-pressure vessels. Summary of the Invention

[0003] In view of this, the present invention aims to propose a forming method for a carbon fiber wound pressure vessel with an opening in the head to solve the problems of internal pressure strength and sealing after opening a hole in the head of a carbon fiber wound pressure vessel.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A forming method for a carbon fiber wound pressure vessel with an opening in the head, the carbon fiber wound pressure vessel with an opening in the head includes a joint metal part, a head opening metal part, an inner liner repair layer, an inner liner layer, and a fiber winding structure layer. The joint metal part includes a metal joint and an opening metal part. The metal joint and the opening metal part are arranged at the left and right ends of the pressure vessel. The head opening metal part is arranged on one side of the metal joint of the pressure vessel. An inner liner repair layer is provided on the outside of the connection part between the head opening metal part and the pressure vessel. The inner surface of the pressure vessel is the inner liner layer, and the outer surface of the pressure vessel is the fiber winding structure layer;

[0006] The forming method for the carbon fiber wound pressure vessel with an opening in the head includes the following steps:

[0007] Step 1: Process a winding mandrel according to the inner profile of the pressure vessel, machine a thread on the head opening metal part, the center line of the thread is consistent with the center line of the opening, and then assemble a set screw, and the end of the set screw is flush with the surface of the mandrel;

[0008] Step 2: Cover a sealing rubber layer on the inner and outer surfaces of the flange of the joint metal part;

[0009] Step 3: Assemble the covered joint metal part to both ends of the mandrel according to the core shaft positioning surface;

[0010] Step 4: Wrap the entire surface of the core mold with two layers of rubber and connect it to the metal joint of the pressure vessel through the reserved overlapping interface.

[0011] Step 5: Uniformly apply the interface adhesive on the surface of the wrapped rubber, remove the rubber at the end of the set screw, and screw it out until it is flush with the rubber surface.

[0012] Step 6: Wrap the fiber winding structure layer on the surface of the wrapped rubber. Before each longitudinal layer winding, screw out the set screw until it is flush with the outer surface of the fiber winding structure layer.

[0013] Step 7: Lay the reinforcement patches between the longitudinal winding layers.

[0014] Step 8: After all the longitudinal layers are wound and the reinforcement patches are laid, assemble the connecting skirt at the small end of the container and the connecting skirt at the large end of the container, and then wind the circumferential layer of the skirt and put it into the furnace for curing.

[0015] Step 9: After curing, take the shell out of the furnace, and use a numerical control machining device or a special tooling to machine circular holes on the composite material head according to the axis of the head opening.

[0016] Step 10: Remove the winding core mold of the shell.

[0017] Step 11: Paste or mold a rubber layer on the surface of the metal part of the head opening. Sandblast the bonding surface between the metal surface and the rubber layer, and apply an adhesive between the rubber and the metal.

[0018] Step 12: Apply an adhesive on the outer surface of the metal of the head opening after pasting the rubber layer. Use the tooling and the thread of the metal part of the head opening to fix the metal part of the head opening to the designed position of the container head. After the adhesive cures, remove the tooling.

[0019] Step 13: Paste two layers of raw rubber sheets between the rubber layer on the surface of the metal part of the head opening inside the container and the rubber layer on the inner surface of the container.

[0020] Step 14: Lay a soft heating sheet on the surface of the pasted raw rubber sheets.

[0021] Step 15: Assemble the plug for the internal pressure test tooling of the container, and pass the control cable of the heating sheet through the reserved hole of the test tooling.

[0022] Step 16: Introduce nitrogen into the container through the test tooling, evacuate the original air, close the container, and pressurize it to 0.5 - 1.0 MPa.

[0023] Step 17: According to the vulcanization characteristics of the selected rubber, use the heating / temperature control device to heat and vulcanize, and then paste two layers of rubber.

[0024] Step 18: After the rubber is vulcanized, let the temperature inside the container naturally drop below 40°C, relieve the internal air pressure, and remove the excess items such as the internal pressure test tooling and the internal heating sheet of the container.

[0025] Step 19: Verify the internal pressure and airtightness test according to the container design requirements.

[0026] Furthermore, container small-end connection skirts and container large-end connection skirts are respectively arranged at both ends of the upper and lower sides of the pressure vessel.

[0027] Furthermore, threads are provided on the outer side of the opening of the head opening metal part.

[0028] Furthermore, a rubber layer is provided on the outer side of the head opening metal part.

[0029] Furthermore, in Step 2, the inner surface of the joint metal part is coated with two layers of 1 mm rubber, two layers of rubber are coated on the inner and outer surfaces, one layer of rubber is coated on the outer surface, and a 20 mm overlapping joint is reserved outside the maximum diameter of the flange.

[0030] Furthermore, in Step 4, the overlapping width of the butt joint of each layer of rubber is not less than 10 mm, and the overlapping seams of the two layers of rubber are staggered from each other.

[0031] Furthermore, in Step 6, the structural layer and total thickness of the fiber winding structure layer are determined according to the use pressure and safety factor by using the mechanical calculation method of composite materials.

[0032] Furthermore, in Step 7, before the reinforcing patch is laid, the set screw is screwed out higher than the thickness of the reinforcing patch on the surface of the winding layer. The reinforcing patch is formed by laminating or winding carbon cloth and glass cloth, a through hole is reserved in the center, the reinforcing patch is assembled and positioned with the through hole through the set screw, and after the reinforcing patch is laid, a thin glass cloth impregnated with winding resin is pasted on the surface for fixation. The number of layers of the reinforcing patch laid is determined according to the mechanical calculation results.

[0033] Furthermore, in Step 1, the core mold adopts a metal skeleton gypsum core mold or a sand core mold structure.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] 1. The present invention solves the problems of the internal pressure strength and sealing after the opening of the container head of the carbon fiber winding pressure vessel.

[0036] 2. The present invention improves the continuity of the fibers in the structural layer of the container head damaged by the opening of the fiber winding container head, and greatly improves the bursting strength of the container.

[0037] 3. The present invention can ensure the sealing performance of the inner lining layer and gives a repair method for the inner lining layer after opening.

[0038] 4. The present invention can ensure that a container with a diameter greater than 1200 mm and an opening at one end not less than 400 mm has a strength and sealing performance not lower than 10.0 MPa. Description of the Drawings

[0039] The accompanying drawings that form a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0040] Figure 1 is the front view of a head-opening carbon fiber wound pressure vessel according to the present invention;

[0041] Figure 2 is the side view of a head-opening carbon fiber wound pressure vessel according to the present invention;

[0042] Figure 3 is the structural schematic diagram of the core mold according to the present invention;

[0043] Figure 4 is the installation schematic diagram of the set screw according to the present invention;

[0044] Figure 5 is the schematic diagram of the head-opening metal part according to the present invention.

[0045] 1 - metal joint, 2 - head-opening metal part, 3 - inner liner repair layer, 4 - small-end connection skirt of the container, 5 - inner liner layer, 6 - fiber winding structure layer, 7 - large-end connection skirt of the container, 8 - opening metal part, 9 - set screw, 10 - thread, 11 - rubber layer. Detailed implementation manners

[0046] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0047] Detailed implementation manner one: Refer to Figures 1-5 To illustrate this implementation manner, a head-opening carbon fiber wound pressure vessel includes a joint metal part, a head-opening metal part 2, an inner liner repair layer 3, an inner liner layer 5, and a fiber winding structure layer 6. The joint metal part includes a metal joint 1 and an opening metal part 8. The metal joint 1 and the opening metal part 8 are arranged at the left and right ends of the pressure vessel. The head-opening metal part 2 is arranged on one side of the metal joint 1 of the pressure vessel. An inner liner repair layer 3 is provided on the outer side of the connection part between the head-opening metal part 2 and the pressure vessel. The inner surface of the pressure vessel is the inner liner layer 5, and the outer surface of the pressure vessel is the fiber winding structure layer 6. The two ends of the upper and lower sides of the pressure vessel are respectively provided with a small-end connection skirt 4 and a large-end connection skirt 7 of the container. A thread 10 is provided on the outer side of the opening of the head-opening metal part 2, and a rubber layer 11 is provided on the outer side of the head-opening metal part 2.

[0048] First, process and wind the mandrel according to the inner surface of the pressure vessel. Machine threads on the metal part 2 of the head opening. The center line of the threads is consistent with the center line of the opening. Then, assemble the set screw 9. The end of the set screw 9 is flush with the surface of the mandrel. Cover the inner and outer surfaces of the flange of the joint metal part with a sealing rubber layer. Assemble the covered joint metal part to both ends of the mandrel according to the core shaft positioning surface. Cover the entire surface of the mandrel with two layers of rubber, and connect it to the metal joint 1 of the pressure vessel through the reserved overlapping interface. Uniformly apply the interface adhesive on the covered rubber surface. Remove the rubber at the end of the set screw 9 and screw it out until it is flush with the rubber surface. Cover the fiber winding structure layer 6 on the rubber surface. Before winding each longitudinal layer, screw out the set screw 9 until it is flush with the outer surface of the fiber winding structure layer 6. Lay the reinforcement patches between the longitudinal winding layers. After all the longitudinal layers are wound and the reinforcement patches are laid, assemble the connecting skirt 4 at the small end of the container and the connecting skirt 7 at the large end of the container. Then, wind the circumferential layer of the skirt and put it into the furnace for curing. After curing, take the shell out of the furnace. Use a numerical control processing equipment or a special tooling to machine circular holes on the composite material head according to the axis of the head opening. Remove the winding mandrel of the shell. Paste or mold a rubber layer 11 on the surface of the metal part 2 of the head opening. Blast the bonding area between the metal surface and the rubber layer. Apply an adhesive between the rubber and the metal. After pasting the rubber layer, apply an adhesive on the outer surface of the metal part 2 of the head opening. Use the tooling and the threads 10 of the metal part 2 of the head opening to fix the metal part 2 of the head opening to the designed position of the container head. After the adhesive cures, disassemble the tooling. Paste two layers of uncured rubber sheets between the rubber layer on the surface of the metal part 2 of the head opening inside the container and the rubber layer on the inner surface of the container. Lay soft heating sheets on the pasted uncured rubber sheets. Assemble the plug for the internal pressure test tooling of the container. Pass the control cable of the heating sheet through the reserved hole of the test tooling. Pass nitrogen into the container through the test tooling, evacuate the original air, and then seal the container. Pressurize it to 0.5 - 1.0 MPa. According to the vulcanization characteristics of the selected rubber, heat and vulcanize it to paste two layers of rubber. After the rubber is vulcanized, let the temperature inside the container drop naturally to below 40°C. Release the internal air pressure, remove the internal pressure test tooling and the heating sheets inside the container and other redundant objects. Conduct internal pressure and airtightness tests for verification according to the design requirements of the container, solve the problems of internal pressure strength and sealing after the head opening of the carbon fiber wound pressure vessel, improve the problem that the fiber continuity of the structure layer of the container head will be damaged after the head opening of the fiber wound container, greatly improve the burst strength of the container, ensure the sealing performance of the inner liner layer 5, and give a repair method for the inner liner layer 5 after the opening, and ensure that the container with a diameter greater than 1200 mm and an opening at one end not less than 400 mm has a strength and sealing performance not lower than 10.0 MPa.

[0049] Specific Embodiment 2: Refer to Figures 1-5 Describe this embodiment. A forming method for a carbon fiber wound pressure vessel with a head opening includes the following steps:

[0050] Step 1: Process and wind the core mold according to the inner surface of the pressure vessel. Machine threads on the metal parts 2 of the head opening, with the thread center line coinciding with the center line of the opening. Then assemble the set screw 9, with the end of the set screw 9 flush with the surface of the core mold. The core mold adopts a metal skeleton gypsum core mold or a sand core mold structure;

[0051] Step 2: Coating the inner and outer surfaces of the flange of the joint metal parts with a sealing rubber layer. Coating two layers of 1mm rubber on the inner surface of the joint metal parts, coating two layers of rubber on the inner and outer surfaces, and coating one layer of rubber on the outer surface. Leave a 20mm overlapping interface outside the maximum diameter of the flange;

[0052] Step 3: Assemble the coated joint metal parts to both ends of the core mold according to the core axis positioning surface;

[0053] Step 4: Coating the entire surface of the core mold with two layers of rubber, connecting it with the metal joint 1 of the pressure vessel through the reserved overlapping interface. The overlapping width of each layer of rubber butt joint is not less than 10mm, and the overlapping seams of the two layers of rubber are staggered from each other;

[0054] Step 5: Uniformly coat the interface adhesive on the surface of the coated rubber, remove the rubber at the end of the set screw 9, and screw it out until it is flush with the rubber surface;

[0055] Step 6: Coating the fiber winding structure layer 6 on the surface of the coated rubber. Before each longitudinal layer winding, screw out the set screw 9 until it is flush with the outer surface of the fiber winding structure layer 6. The structural layer and total thickness of the fiber winding structure layer 6 are determined according to the working pressure and safety factor using the mechanical calculation method of composite materials;

[0056] Step 7: Lay the reinforcing sheets between the longitudinal winding layers;

[0057] Step 8: After all the longitudinal layers are wound and the reinforcing sheets are laid, assemble the small-end connection skirt 4 and the large-end connection skirt 7 of the container, and then wind the circumferential layer of the skirt and put it into the furnace for curing. Before the reinforcing sheet is laid, screw out the set screw 9 higher than the thickness of the reinforcing sheet on the surface of the winding layer. The reinforcing sheet is formed by laminating or winding carbon cloth and glass cloth, with a through hole reserved in the center. The reinforcing sheet is assembled and positioned through the set screw 9 and the through hole. After the reinforcing sheet is laid, a thin glass cloth impregnated with winding resin is pasted on the surface for fixation. The number of layers of the reinforcing sheet is determined according to the mechanical calculation results;

[0058] Step 9: After curing, take the shell out of the furnace, and machine circular holes on the composite material head according to the head opening axis by using a numerical control processing equipment or a special tooling;

[0059] Step 10: Demount the winding core mold of the shell;

[0060] Step 11: Paste or mold a rubber layer 11 on the surface of the metal parts 2 of the head opening. Sandblast the bonding part between the metal surface and the rubber layer, and apply an adhesive between the rubber and the metal;

[0061] Step 12: Apply an adhesive to the outer surface of the metal 2 of the head opening after pasting the rubber layer. Fix the metal part 2 of the head opening to the designed position of the container head by using the tooling and the thread 10 of the metal part 2 of the head opening, and remove the tooling after the adhesive cures.

[0062] Step 13: Paste two layers of uncured rubber sheets between the rubber layer on the surface of the metal part 2 of the head opening inside the container and the rubber layer on the inner surface of the container.

[0063] Step 14: Lay a soft heating sheet on the surface of the pasted uncured rubber sheets.

[0064] Step 15: Assemble the plug of the internal pressure test tooling for the container, and pass the control cable of the heating sheet through the reserved hole of the test tooling.

[0065] Step 16: Introduce nitrogen into the container through the test tooling, evacuate the original air, close the container, and pressurize it to 0.5 - 1.0 MPa.

[0066] Step 17: According to the selected rubber vulcanization characteristics, heat and vulcanize to paste two layers of rubber by using the heating / temperature control device.

[0067] Step 18: After the rubber is vulcanized, let the temperature inside the container naturally drop below 40°C, relieve the internal air pressure, and remove the redundant items such as the internal pressure test tooling and the heating sheet inside the container.

[0068] Step 19: Conduct internal pressure and airtightness test verification according to the design requirements of the container.

[0069] The embodiments of the present invention disclosed above are only used to help illustrate the present invention. The embodiments do not describe all the details in detail, nor limit the invention to the specific embodiments described. According to the content of this specification, many modifications and variations can be made. These embodiments are selected and specifically described in this specification to better explain the principle and practical application of the present invention, so that those skilled in the art in the relevant technical field can well understand and utilize the present invention.

Claims

1. A forming method for a carbon fiber wound pressure vessel with an opening on the head, characterized in that: The head-opening carbon fiber wound pressure vessel described above comprises a joint metal part, a head-opening metal part (2), a lining repair layer (3), a lining layer (5), and a fiber winding structure layer (6). The joint metal part comprises a metal joint (1) and an opening metal part (8). The metal joint (1) and the opening metal part (8) are arranged at the left and right ends of the pressure vessel. The head-opening metal part (2) is arranged on one side of the metal joint (1) of the pressure vessel. An outer side of the connection part between the head-opening metal part (2) and the pressure vessel is provided with a lining repair layer (3). The inner surface of the pressure vessel is a lining layer (5), and the outer surface of the pressure vessel is a fiber winding structure layer (6). The forming method of the head-opening carbon fiber wound pressure vessel comprises the following steps: Step 1: Process a winding mandrel according to the inner profile of the pressure vessel. Machine a thread on the head-opening metal part (2), with the center line of the thread being consistent with the center line of the opening. Then assemble a set screw (9), and the end of the set screw (9) is flush with the surface of the mandrel. Step 2: Cover the inner and outer surfaces of the flange of the joint metal part with a sealing rubber layer. Step 3: Assemble the covered joint metal part to both ends of the mandrel according to the core shaft positioning surface. Step 4: Cover the entire surface of the mandrel with two layers of rubber, and connect it to the metal joint (1) of the pressure vessel through a reserved overlapping interface. Step 5: Uniformly apply an interface adhesive to the covered rubber surface, remove the rubber at the end of the set screw (9), and screw it out until it is flush with the rubber surface. Step 6: Cover the fiber winding structure layer (6) on the covered rubber surface. Before each longitudinal layer winding, screw out the set screw (9) until it is flush with the outer surface of the fiber winding structure layer (6). Step 7: Lay a reinforcing sheet between the longitudinal winding layers. Step 8: After all the longitudinal layers are wound and the reinforcing sheets are laid, assemble the small-end connection skirt (4) and the large-end connection skirt (7) of the container, and then wind the circumferential layer of the skirt and put it into the furnace for curing. Step 9: After the cured shell is taken out of the furnace, use a numerical control machining device or a special tooling to machine a round hole on the composite material head according to the head-opening axis. Step 10: Remove the winding mandrel of the shell. Step 11: Paste or mold a rubber layer (11) on the surface of the head-opening metal part (2). Blast the bonding part between the metal surface and the rubber layer, and apply an adhesive between the rubber and the metal. Step 12: Apply an adhesive to the outer surface of the head-opening metal (2) after pasting the rubber layer. Use the tooling and the thread (10) of the head-opening metal part (2) to fix the head-opening metal part (2) to the designed position of the container head. After the adhesive cures, disassemble the tooling. Step 13: Paste two layers of raw rubber sheets between the rubber layer on the surface of the head-opening metal part (2) inside the container and the rubber layer on the inner surface of the container. Step 14: Lay a soft heating sheet on the pasted raw rubber sheet surface. Step 15: Assemble the plug for the internal pressure test tooling of the container, and pass the control cable of the heating sheet through the reserved hole of the test tooling. Step 16: Pass nitrogen into the container through the test tooling, evacuate the original air, close the container, and pressurize it to 0.5 - 1.0 MPa. Step 17: According to the selected rubber vulcanization characteristics, use a heating / temperature control device to heat and vulcanize and then paste two layers of rubber. Step 18: After the rubber is vulcanized, the inside of the container is naturally cooled to below 40°C, the internal air pressure is removed, and the redundant items such as the internal pressure test tooling and the heating sheet inside the container are removed. Step 19: Conduct internal pressure and airtightness test verification according to the container design requirements.

2. The forming method of a carbon fiber wound pressure vessel with a head opening according to claim 1, characterized in that: At both ends of the upper and lower sides of the pressure vessel, a container small-end connection skirt (4) and a container large-end connection skirt (7) are respectively provided.

3. The forming method of a carbon fiber wound pressure vessel with an opening on the head according to claim 1, characterized in that: A thread (10) is provided on the outer side of the opening of the head opening metal part (2).

4. The forming method of a head-opening carbon fiber wound pressure vessel according to claim 1, characterized in that: A rubber layer (11) is provided on the outer side of the head opening metal part (2).

5. The forming method of a carbon fiber wound pressure vessel with an opening on the head according to claim 1, characterized in that: In Step 2, the inner surface of the joint metal part is coated with two layers of 1-mm rubber, two layers of rubber are coated on the inner and outer surfaces, one layer of rubber is coated on the outer surface, and a 20-mm butt joint is reserved outside the maximum diameter of the flange.

6. The forming method of a carbon fiber wound pressure vessel with a head opening according to claim 1, characterized in that: In Step 4, the butt joint width of each layer of rubber is not less than 10 mm, and the butt joints of the two layers of rubber are staggered from each other.

7. A forming method of a carbon fiber wound pressure vessel with a head opening according to claim 1, characterized in that: In Step 6, the structural layer and the total thickness of the fiber winding structure layer (6) are determined by using the composite material mechanics calculation method according to the use pressure and the safety factor.

8. A forming method of a carbon fiber wound pressure vessel with an opening on the head according to claim 1, characterized in that: In Step 7, before the reinforcing patch is laid, the set screw (9) is screwed out higher than the thickness of the reinforcing patch on the surface of the winding layer. The reinforcing patch is formed by laminating or winding carbon cloth and glass cloth, and a through hole is reserved in the center. The reinforcing patch is assembled and positioned with the through hole through the set screw (9). After the reinforcing patch is laid, a thin glass cloth impregnated with winding resin is pasted on the surface for fixation. The number of layers of the reinforcing patch laid is determined according to the mechanical calculation results.

9. The forming method of a carbon fiber wound pressure vessel with a head opening according to claim 1, characterized in that: In Step 1, the core mold adopts a metal skeleton gypsum core mold or a sand core mold structure.

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