Integrated forming mold for composite barrel-shaped pressure-resistant shell and preparation process of composite barrel-shaped pressure-resistant shell

Abstract

The invention discloses a composite barrel-shaped pressure-resistant shell integrated forming mold and a preparation process thereof, and belongs to the field of submersible pressure-resistant shells. The device is of a barrel-shaped structure formed by rotating a curve with a positive Gaussian curvature. After a plurality of groups of non-preferential circular arc surface sections and preferential circular arc surface sections are arranged at intervals to form a barrel-shaped structure, the top end and the bottom end are fixedly spliced through flanges to form a complete mold for preparing the pressure-resistant shell; a plurality of groups of uniformly distributed annular grooves are formed in the surface of the mold; the fibers are infiltrated with reinforced resin; performing integral winding and curing molding on the mold by adopting a fiber winding process; and naturally cooling and demolding. The mold manufactured by the method is simple and easy to understand, is formed by assembling a plurality of preferential and non-preferential arc surface sections, can realize the preparation of the positive Gaussian curvature reinforced shell, and is convenient to demold.

Description

Technical Field

[0001] The present invention belongs to the field of submersible pressure hulls, and in particular relates to an integrated molding die for a composite barrel-shaped pressure hull and a preparation process thereof. Background Art

[0002] Submersibles are essential basic equipment for human beings to explore the ocean and develop marine resources. The pressure hull is the core component of the submersible. During the diving process of the submersible, the pressure hull can ensure that the internal equipment is not damaged and the safety of the staff. Its structural form and material selection directly affect the payload of the submersible. At present, the most commonly used pressure hull forms are cylindrical and spherical, but the stability of the cylindrical structure is relatively poor and it is easy to become unstable. The spherical structure has low space utilization, poor hydrodynamic characteristics, and is more sensitive to defects and difficult to manufacture. The barrel structure with curvature neutralizes the disadvantages of the cylindrical and spherical structures and demonstrates good performance. At the same time, reinforcement, as a very common method to improve the stability of the pressure hull, can control the utilization rate of material properties and the increase in weight and cost as much as possible.

[0003] Composite materials have shown great potential in the application of submersible pressure hulls due to their high specific strength, corrosion resistance, fatigue resistance, and material designability, and have received extensive attention from submersible research institutions around the world. Compared with metal pressure hulls of the same size, pressure hulls made of carbon fiber composite materials can reduce weight by about 50%.

[0004] The fiber winding molding technology has very outstanding advantages. It has a high volume content of prepared fibers, can change the fiber winding angle, and has high production efficiency. It is suitable for the preparation of rotating components such as cylindrical and barrel-shaped components. At present, there are four main types of fiber-wound composite shells, namely single spiral winding, spiral plus circumferential winding, spiral plus longitudinal winding, and longitudinal plus circumferential winding. Compared with molding processes such as molding and lamination, the fiber winding process can make the shell have fewer process defects and better mechanical properties. Summary of the invention

[0005] The purpose of the present invention is to provide an integrated molding die and preparation process for a fiber-wound composite reinforced barrel-shaped pressure-resistant shell. The two ends are transitioned to the cylindrical shell through rounded corners, which can effectively avoid stress concentration at the end cover connection during the experiment. The manufactured barrel-shaped pressure-resistant shell has better stability and low manufacturing difficulty, while ensuring the better mechanical properties of the shell.

[0006] The present invention adopts a fiber winding integrated molding process to prepare the shell. After the rib winding is completed (or the metal ribs are added), a reinforced barrel-shaped pressure-resistant shell can be manufactured according to whether the ribs are coated with a release agent and a release cloth is laid.

[0007] To achieve the above objectives, the technical solution adopted by the present invention includes:

[0008] The invention provides a composite barrel-shaped pressure-resistant shell, which is a barrel-shaped structure formed by rotating a curve with positive Gaussian curvature.

[0009] Furthermore, annular metal ribs or carbon fiber ribs are evenly arranged inside the barrel-shaped pressure-resistant shell from the top to the bottom.

[0010] The present invention further provides an integrated molding mold for a composite barrel-shaped pressure-resistant shell, comprising non-priority arc surface petals and priority arc surface petals. After multiple groups of non-priority arc surface petals and priority arc surface petals are alternately arranged to form a barrel-shaped structure, the top and bottom ends are fixed and spliced ​​by flanges to form a complete mold, and the surface of the mold is provided with multiple groups of evenly distributed annular grooves; the non-priority arc surface petals include bottle mouths at the top and bottom ends and arc surfaces protruding outward in the middle, and the arc surfaces are a structure that gradually shrinks from the middle to the top and bottom ends; the priority arc surface petals include bottle mouths at the top and bottom ends and arc surfaces protruding outward in the middle, and the arc surfaces are a structure that gradually expands from the middle to the top and bottom ends.

[0011] Furthermore, the inclined surfaces on both sides of the non-priority arc surface petals and the priority arc surface petals fit together, and the deflection angle of the contact surfaces of the priority arc surface petals is 30°~45°; a non-priority arc surface petal and a priority arc surface petal are a group; the non-priority arc surface petals and the priority arc surface petals are 3 to 5 groups.

[0012] Furthermore, the bottle mouths at the top and bottom ends are transitioned through rounded corners and arc surfaces; the curvature of the mold is equal to the curvature of the barrel-shaped pressure-resistant shell; and the outer radius of the flanges (3) at both ends is equal to the outer radius of the bottle mouths at the top and bottom ends.

[0013] The present invention further provides a fiber-wound composite barrel-shaped pressure-resistant shell integrated molding preparation process, comprising the following steps:

[0014] Step 1: Determine the curvature of the barrel-shaped pressure shell and make an integrated molding mold; place the integrated molding mold in an oven for preheating and apply a release agent;

[0015] Step 2: The fiber is impregnated with a reinforcing resin; the mold is wound as a whole using a fiber winding process to form an integrated structure;

[0016] Step 3: Place the wound mold in an autoclave for heating and curing; the curing pressure is 1-2Mpa, the curing temperature is 120-130°C, and the curing time is 100-120min;

[0017] Step 4: Cool naturally to demould, first remove a priority arc surface petal, and then remove the non-priority arc surface petal.

[0018] Furthermore, in step 1, the preheating temperature is 80-90° C., and the preheating time is 25-35 minutes.

[0019] Furthermore, the step 2 is specifically as follows: firstly circumferentially wind carbon fiber ribs or insert annular metal ribs in the surface grooves of the mold, and after being flush with the outer surface of the mold, use a fiber winding process to wind the mold as a whole; and finally in step 4, an internally reinforced composite barrel-shaped pressure-resistant shell is prepared.

[0020] Furthermore, the step 2 is specifically as follows: an annular metal rib is placed in the surface groove of the mold, and after it is flush with the outer surface of the mold, a release agent is applied to the outer surface of the metal rib, and the mold is wound as a whole using a fiber winding process; finally, in step 4, a composite barrel-shaped pressure-resistant shell without internal reinforcement is prepared.

[0021] Furthermore, in step 2, the fiber winding method includes circumferential winding and spiral winding; the circumferential winding angle is 90°, and the spiral winding angle is an acute angle; and the fiber winding process is a wet winding process.

[0022] The beneficial effects of the present invention are:

[0023] 1. The present invention adopts an integrated molding preparation method, which can reduce the process defects caused by the bonding of ribs and shells, affecting the performance of the pressure hull, and greatly shortens the preparation process, improves the preparation efficiency, and can be mass-produced; the method of the present invention has a wide range of applications, can achieve three configurations of full carbon fiber reinforcement, metal reinforcement and no reinforcement, and is easy to operate.

[0024] 2. The present invention uses a barrel-shaped pressure-resistant shell with a curvature, which has higher stability and effectively improved pressure resistance compared to a cylindrical shell; the shell is made of composite materials, which greatly reduces the mass of the components and can improve the bearing capacity of the shell compared to traditional metal materials.

[0025] 3. The barrel-shaped pressure-resistant shell made by the present invention has two ends transitioned to the cylindrical shell through rounded corners, which facilitates the connection of the end covers during experiments and avoids stress concentration at the connection. The fiber winding process can reduce various process defects caused by hand-laid prepreg and improve material utilization.

[0026] 4. The mold manufactured by the present invention is simple and easy to understand. It is assembled from multiple priority and non-priority arc surfaces, which can realize the preparation of positive Gaussian curvature reinforced shells, and is easy to demold, which can reduce the time spent in the preparation process. The present invention provides a fiber-wound composite reinforced barrel-shaped pressure-resistant shell integrated molding process with high engineering application value, which can provide a certain reference for the development of national marine submersibles. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the integrated molding die before and after assembly in the present invention;

[0028] Figure 2 1. It is a front view of the integrated molding die before and after assembly in the present invention;

[0029] Figure 3 It is a schematic diagram of the flange for fixing the mold petals in the present invention;

[0030] Figure 4 It is a schematic diagram of the non-preferred arc surface petal division of the mold in the present invention;

[0031] Figure 5 It is a schematic diagram of the arc surface petal division of the mold preferred item in the present invention;

[0032] Figure 6 It is a schematic diagram after assembly without a fixing flange in the present invention;

[0033] Figure 7 It is a schematic diagram of the metal ribs in the present invention;

[0034] Figure 8 is a schematic diagram of a reinforced barrel-shaped pressure hull prepared by the method of the present invention;

[0035] Fig. 9 It is a schematic diagram of an unreinforced barrel-shaped pressure hull prepared by the method of the present invention.

[0036] The names and reference numerals of the components involved in the above drawings are as follows:

[0037] Non-priority arc surface petal 1, priority arc surface petal 2, flange 3, bolt 4, metal rib 5, reinforced barrel-shaped pressure hull 6, unreinforced barrel-shaped pressure hull 7. DETAILED DESCRIPTION

[0038] The present invention is further described below in conjunction with the accompanying drawings.

[0039] The technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0040] Instructions for preparation and assembly of integrated molding mold:

[0041] Figure 1 , 2 The integrated molding die of the present invention is shown. Figure 4 The non-preferred circular arc surface is shown as 1 and Figure 5 The preferred arc surface petals 2 are arranged alternately along the circumference and assembled in sequence. Figure 6 The deflection angle of the contact surface between the preferred arc surface petal 2 and the non-preferred arc surface petal 1 is 30° to 45°, which is convenient for later demoulding. Figure 3 The flange 3 and bolt 4 shown are fixedly connected, and the outer radius of the flange 3 at both ends should be equal to the outer radius of the connected cylinder to avoid the radius being too large to affect the arrangement of the winding angle;

[0042] Preparation process and description of integrated pressure hull:

[0043] First of all, Figure 1 The mold shown is assembled from a plurality of preferred arc surface petals 2 and a non-preferred arc surface petal 1 fixedly connected by flanges 3 and bolts 4, and is preheated and coated with a release agent to maintain the mold and prevent fiber filaments from adhering to the mold;

[0044] The mold material is 45# steel, the metal rib 5 material is 304 stainless steel, and the winding material is a composite material of T700 fiber impregnated with reinforced resin.

[0045] The invention discloses a composite barrel-shaped pressure-resistant shell, which is a barrel-shaped structure with a middle portion protruding outward and gradually shrinking from the middle to the top and bottom ends; annular metal ribs or carbon fiber ribs are evenly arranged inside the composite barrel-shaped pressure-resistant shell from the top to the bottom.

[0046] The present invention further discloses a mold for preparing a composite barrel-shaped pressure-resistant shell. The mold is composed of a plurality of preferred circular arc surface petals 2 and a plurality of non-preferred circular arc surface petals 1 connected by flanges 3 at both ends and fixed by bolts 4 to form the mold.

[0047] The present invention further discloses a process method for a fiber-wound composite barrel-shaped pressure hull, comprising: winding carbon fibers impregnated with reinforcing resin on a mold in a circumferential winding manner, a spiral winding manner, etc. according to a required winding angle and thickness to form an uncured pressure hull, wherein the circumferential winding angle is 90° and the spiral winding angle is an acute angle; using the fiber winding process, whether or not metal ribs 5 are added, a fully composite reinforced barrel-shaped pressure hull, a metal reinforced barrel-shaped pressure hull 6 and an unreinforced barrel-shaped pressure hull 7 can be integrally formed.

[0048] The uncured pressure-resistant shell is placed in an autoclave for heating and curing;

[0049] After curing is completed, it is naturally cooled to room temperature, and finally demoulding is performed to remove the pressure-resistant shell.

[0050] According to the required requirements, the curvature of the shell is first determined, and the mold is made after modeling. Through fiber winding and one-piece molding, a composite barrel-shaped pressure-resistant shell with curvature and better stability can be obtained.

[0051] A fiber-wound composite barrel-shaped pressure-resistant shell integrated molding die and a preparation process thereof, the process comprising the following steps:

[0052] Step 1: Choose mold material: Use 45# steel;

[0053] Step 2, mold structure design: after determining the shell curvature, the mold is composed of a plurality of priority arc surface petals and non-priority arc surface petals, and the deflection angle of the contact surface between the priority arc surface petals and the non-priority arc surface petals is 30° to 45°;

[0054] Step 3, mold assembly: The mold is composed of a plurality of priority arc surface petals and non-priority arc surface petals, which are alternately arranged along the circumference, and the two ends are fixedly connected by flanges;

[0055] Step 4: Metal rib material selection: 304 stainless steel;

[0056] Step 5: Winding material selection: T700 fiber impregnated with reinforced resin;

[0057] Step 6: Preheating the mold: Place the mold in an oven for preheating and apply a release agent. The preheating temperature is 80-90°C and the preheating time is 25-35 minutes.

[0058] Step 7: Integral molding of the reinforced pressure-resistant shell of all-composite materials: first, apply a mold release agent to the mold, then wrap the fiber around the groove at 90 degrees, and after it is flush with the outer surface of the mold, perform overall winding molding;

[0059] Step 8: One-piece molding of metal reinforced pressure-resistant shell: first, apply a release agent to the mold, place the metal ribs in the grooves, and then fix the mold through the flange. No release agent is applied to the outer surface of the metal ribs, and finally, the fiber is wound around the outer surface of the mold to form the mold;

[0060] Step 9: Unreinforced pressure shell: first place the metal ribs in the grooves, and fix the mold through the flanges, then apply a release agent on the entire outer surface of the mold, and at the same time, lay a release cloth, and finally wrap the fibers around the outer surface of the mold to form the mold;

[0061] Step 10, heating and curing: placing in an autoclave for heating and curing, the curing pressure is 1-2 MPa, the curing temperature is 120-130°C, and the curing time is 100-120 minutes;

[0062] Step 11. Demolding the mold: After natural cooling, demold the mold. After removing the bolts at both ends, remove the priority arc surface petals first, and then remove the remaining petals in turn.

[0063] Example 1

[0064] All-composite reinforced pressure-resistant shell is formed in one piece: Figure 8 The figure shows the reinforced barrel-shaped pressure hull 6 of the present invention;

[0065] Step 1: Use 45# steel as the mold material and prepare the mold according to the curvature of the pressure shell;

[0066] Step 2: Preheat the mold and apply a release agent. Place the mold in an oven for preheating and apply a release agent. The preheating temperature is 80°C and the preheating time is 30 minutes.

[0067] Step 3: Then, the fiber is wound at 90 degrees around the groove to form a composite material rib, which is then wound flush with the outer surface of the mold and then wound as a whole; the wound all-composite reinforced pressure shell rib is integrally formed with the shell, and the two ends are transitioned to the cylindrical shell through fillets, which can facilitate the connection of the end cover and avoid stress concentration at the connection;

[0068] Step 4: After winding is completed, put it into the autoclave for heating and curing (heating and pressurization are more uniform), the curing pressure is 1-2MPa, the curing temperature is 120-130℃, and the curing time is 100-120 minutes;

[0069] Step 5: After natural cooling, demoulding is carried out, the bolts 4 at both ends are removed, and then the flanges 3 at both ends are removed, and then the priority arc surface petal 2 is removed first, and then the remaining petals are removed in turn.

[0070] Embodiment 2:

[0071] Metal reinforced pressure-resistant shell is integrally formed: Figure 8 The figure shows the reinforced barrel-shaped pressure hull 6 of the present invention;

[0072] Step 1: Use 45# steel as the mold material and prepare the mold according to the curvature of the pressure shell;

[0073] Step 2: Preheat the mold and apply a release agent. Place the mold in an oven for preheating and apply a release agent. The preheating temperature is 80°C and the preheating time is 30 minutes.

[0074] Step 3: Figure 7The metal rib 5 shown is placed in the groove, and then the preferred arc surface petal 2 and the non-preferred arc surface petal 1 are connected and fixed by flange 3 and bolt 4 to assemble into a mold. No release agent is applied to the outer surface of the metal rib 5. Since the wound fiber filaments soaked in resin are sticky, the shell and the rib can be fully bonded. Finally, the fiber is wound on the outer surface of the mold to form a shape. The wound metal reinforced pressure shell rib is in full contact with the shell, and the two ends are transitioned to the cylindrical shell through fillets, which can facilitate the connection of the end cover and avoid stress concentration at the connection.

[0075] Step 4: After winding is completed, put it into the autoclave for heating and curing (heating and pressurization are more uniform), the curing pressure is 1-2MPa, the curing temperature is 120-130℃, and the curing time is 100-120 minutes;

[0076] Step 5: After natural cooling, demoulding is carried out, the bolts 4 at both ends are removed, and then the flanges 3 at both ends are removed, and then the priority arc surface petal 2 is removed first, and then the remaining petals are removed in turn.

[0077] Embodiment 3:

[0078] Unreinforced pressure hull: Fig. 9 The figure shows the unreinforced barrel-shaped pressure hull 7 of the present invention;

[0079] Step 1: Use 45# steel as the mold material and prepare the mold according to the curvature of the pressure shell;

[0080] Step 2: Preheat the mold and apply a release agent. Place the mold in an oven for preheating and apply a release agent. The preheating temperature is 80°C and the preheating time is 30 minutes.

[0081] Step 3: Assemble the priority arc surface petal 2 and the non-priority arc surface petal 1, and place the metal rib 5 in the groove, connect and fix them through flange 3 and bolt 4, and then apply the release agent to the entire outer surface of the mold. The release agent is applied to the outer surface of the rib to facilitate the removal of the rib together during the later demoulding; at the same time, the demoulding cloth can be laid, and finally the fiber winding is formed on the outer surface of the mold. The two ends of the barrel-shaped pressure-resistant shell are transitioned to the cylindrical shell through fillets, which can facilitate the connection of the end cover and avoid stress concentration at the connection;

[0082] Step 4: After winding is completed, put it into the autoclave for heating and curing (heating and pressurization are more uniform), the curing pressure is 1-2MPa, the curing temperature is 120-130℃, and the curing time is 100-120 minutes;

[0083] Step 5: After natural cooling, demoulding is carried out, the bolts 4 at both ends are removed, and then the flanges 3 at both ends are removed, and then the priority arc surface petals 2 are removed first, and then the remaining petals are removed in turn, and the metal ribs 5 are removed. Since the middle diameter of the shell is large and the diameters at both ends are small, each annular rib can be divided into 3 or 4 petals at this time, and they can be fixed by gluing or wrapping a layer of film on the outer surface (glue that fails at the curing temperature or film that does not affect the winding process can be used) to facilitate removal.

[0084] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that various substitutions and modifications are possible without departing from the spirit and scope of the present invention and the appended claims, and that the embodiments should therefore be considered exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the foregoing description, and it is intended that all changes falling within the meaning and scope of the equivalents of the claims be encompassed within the present invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0085] In addition, it should be understood that although this specification is described according to implementation methods, not every implementation method contains only one independent technical solution. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A composite barrel-shaped pressure hull, characterized in that: A barrel-shaped structure formed by rotating a curve with positive Gaussian curvature.

2. The composite barrel-shaped pressure hull according to claim 1, characterized in that: The barrel-shaped pressure-resistant shell is evenly provided with annular metal ribs or carbon fiber ribs from the top to the bottom.

3. A composite barrel-shaped pressure-resistant shell integrated molding die for preparing the composite barrel-shaped pressure-resistant shell according to claim 1 or 2, characterized in that: The invention comprises non-priority arc surface petals (1) and priority arc surface petals (2). After a plurality of groups of non-priority arc surface petals (1) and priority arc surface petals (2) are alternately arranged to form a barrel-shaped structure, the top and bottom ends are fixedly spliced ​​by flanges (3) to form a complete mold, and the surface of the mold is provided with a plurality of groups of evenly distributed annular grooves; the non-priority arc surface petals (1) comprise bottle openings at the top and bottom ends and an arc surface protruding outwards in the middle, and the arc surface is a structure that gradually contracts from the middle to the top and bottom ends; the priority arc surface petals (2) comprise bottle openings at the top and bottom ends and an arc surface protruding outwards in the middle, and the arc surface is a structure that gradually expands from the middle to the top and bottom ends.

4. The composite barrel-shaped pressure-resistant shell integrated molding die according to claim 3, characterized in that: The inclined surfaces on both sides of the non-priority circular arc surface petals (1) and the priority circular arc surface petals (2) match each other, and the deflection angle of the contact surface of the priority circular arc surface petals (2) is 30° to 45°; the non-priority circular arc surface petals (1) and the priority circular arc surface petals (2) are 3 to 5 groups.

5. The composite barrel-shaped pressure-resistant shell integrated molding die according to claim 3, characterized in that: The bottle mouths at the top and bottom ends are transitioned through rounded corners and arc surfaces; the curvature of the mold is equal to the curvature of the barrel-shaped pressure-resistant shell; and the outer radius of the flanges (3) at both ends is equal to the outer radius of the bottle mouths at the top and bottom ends.

6. A process for preparing the composite barrel-shaped pressure-resistant shell according to claim 1 or 2, characterized in that: The following steps are involved: Step 1: Determine the curvature of the barrel-shaped pressure hull and make an integrated molding mold; Place the integrated molding mold in an oven for preheating and apply a release agent; Step 2: The fiber is impregnated with a reinforcing resin; the mold is wound as a whole using a fiber winding process to form an integrated structure; Step 3: Place the wound mold in an autoclave for heating and curing; the curing pressure is 1-2Mpa, the curing temperature is 120-130°C, and the curing time is 100-120min; Step 4: Cool naturally and demould, first remove a priority arc surface flap (2), and then remove the non-priority arc surface flap (1).

7. The integrated molding preparation process of composite barrel-shaped pressure-resistant shell according to claim 6 is characterized in that: In step 1, the preheating temperature is 80-90° C. and the preheating time is 25-35 minutes.

8. The integrated molding preparation process of composite barrel-shaped pressure-resistant shell according to claim 6 is characterized in that: The step 2 is specifically as follows: firstly circumferentially wind carbon fiber ribs or insert annular metal ribs in the surface grooves of the mold, and after being flush with the outer surface of the mold, use a fiber winding process to wind the mold as a whole; and finally in step 4, an internally reinforced composite barrel-shaped pressure-resistant shell is prepared.

9. The integrated molding preparation process of composite barrel-shaped pressure-resistant shell according to claim 6 is characterized in that: The step 2 specifically comprises: placing an annular metal rib in the surface groove of the mold, and after it is flush with the outer surface of the mold, applying a release agent on the outer surface of the metal rib, and then winding the mold as a whole using a fiber winding process; and finally in step 4, a composite barrel-shaped pressure-resistant shell without internal reinforcement is prepared.

10. The integrated molding preparation process of composite barrel-shaped pressure-resistant shell according to claim 6, characterized in that: In step 2, the fiber winding method includes circumferential winding and spiral winding; the circumferential winding angle is 90°, and the spiral winding angle is an acute angle; and the fiber winding process is a wet winding process.

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