A carbon fiber full-winding method with patch reinforcement at the cylinder shoulder of a cylinder liner

Abstract

The application discloses a kind of carbon fiber full-winding methods of patch reinforcement at gas cylinder liner shoulder, the gas cylinder liner includes barrel and two bottle shoulder, stress concentration is generated at the curvature mutation of bottle shoulder, patch reinforcement layer is provided at bottle shoulder, annular winding layer is provided at barrel, annular winding layer and patch reinforcement layer seamlessly link, annular winding layer and patch reinforcement layer are provided with spiral winding layer outside, annular winding layer and spiral winding layer jointly constitute carbon fiber composite material winding layer;Method includes: step one, gas cylinder liner pretreatment;Step two, gas cylinder stress analysis;Step three, gas cylinder patch planning;Step four, gas cylinder liner is clamped;Step five, prepreg cutting;Step six, local laying of prepreg;Step seven, gas cylinder liner annular winding.This method reduces the waste of carbon fiber material, accurately reinforces bottle shoulder weak area, improves gas cylinder carrying capacity, while reducing gas cylinder thickness and weight.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnel construction, in particular to a carbon fiber full-winding method for patch reinforcement at the bottle shoulder of a gas cylinder liner. BACKGROUND

[0002] Plastic liner carbon fiber full-winding composite gas cylinders are widely used in high-pressure gas storage and transportation fields due to their lightweight, excellent corrosion resistance, and avoidance of hydrogen embrittlement. The bottle shoulder, as a key stress-bearing part of the gas cylinder, bears complex stress from high-pressure gas, and its reinforcement effect directly determines the carrying capacity and safety performance of the gas cylinder. Therefore, bottle shoulder reinforcement is a core link in the manufacturing of such gas cylinders.

[0003] The existing bottle shoulder reinforcement manufacturing technologies have many technical problems: the traditional winding process achieves reinforcement through alternating spiral and ring winding, which can meet the basic pressure-bearing requirements, but the bottle shoulder reinforcement relies on a large number of winding layers, resulting in serious material waste and insufficient reinforcement accuracy; the independent reinforcement patch process requires winding, curing, and cutting with an independent mold, and then bonding to the bottle shoulder, which not only has a complex process flow and low production efficiency, but also the secondary bonding interface is prone to become a weak link, affecting the fatigue life and gas tightness of the gas cylinder; the layer optimization process improves the overall performance of the gas cylinder by adjusting the overall layer sequence and angle, but it does not design a local precise reinforcement scheme for the stress concentration area of the bottle shoulder, and still relies on global spiral winding layers for reinforcement, which is not ideal in terms of material utilization and reinforcement specificity; the existing full-winding process focuses on the matching of the overall layer of the cylinder body and the head, and the bottle shoulder still uses the traditional spiral winding reinforcement mode, which does not adequately relieve stress concentration, and does not achieve seamless connection between local reinforcement and overall winding, limiting the efficiency improvement.

[0004] In summary, the existing technologies have not effectively solved the core technical problems of carbon fiber waste, insufficient reinforcement accuracy, and poor load-carrying capacity and weight balance in the bottle shoulder reinforcement process, making it difficult to meet the application requirements of lightweight, high safety, and low cost gas cylinders, and there is an urgent need to innovate a precise, efficient, and energy-saving bottle shoulder reinforcement process. SUMMARY

[0005] The present application aims to provide a carbon fiber full-winding method for patch reinforcement at the bottle shoulder of a gas cylinder liner, to solve the technical problems of carbon fiber waste, insufficient reinforcement accuracy, and poor load-carrying capacity and weight balance in the bottle shoulder reinforcement of existing carbon fiber full-winding composite material gas cylinders.

[0006] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] A kind of carbon fiber full-winding method of patch reinforcement at cylinder shoulder of cylinder liner, the cylinder liner includes barrel and two cylinder shoulders, stress concentration is generated at the place of curvature mutation of cylinder shoulder, patch reinforcement layer is arranged at the cylinder shoulder, annular winding layer is arranged at the barrel of cylinder liner, annular winding layer and patch reinforcement layer seamlessly link, spiral winding layer is arranged outside annular winding layer and patch reinforcement layer, and annular winding layer and spiral winding layer jointly constitute carbon fiber composite material winding layer;

[0008] The method comprises the following steps:

[0009] Step one, cylinder liner pretreatment: the cylinder liner is treated by using plasma treatment process;

[0010] Step two, cylinder stress analysis: based on cylinder design load and cylinder liner three-dimensional model, stress simulation analysis is carried out by using ANSYS finite element analysis software, cylinder stress distribution is obtained by solving, and the position of local laying of pre-impregnated sheet at cylinder shoulder is determined;

[0011] Step three, cylinder patch planning: based on stress distribution result, CAD-CAM software is used to plan the laying position, size, shape, layer angle and layer number of pre-impregnated sheet;

[0012] Step four, cylinder liner clamping: the pretreated cylinder liner is positioned and clamped on six-axis robot patching equipment;

[0013] Step five, pre-impregnated sheet cutting: carbon fiber and epoxy resin pre-impregnated unidirectional tape are connected to six-axis robot patching equipment, pre-impregnated sheet is cut according to the planned size and shape of pre-impregnated sheet, and the cut pre-impregnated sheet is quickly positioned and weighed;

[0014] Step six, pre-impregnated sheet local laying: six-axis robot patching equipment clamps qualified pre-impregnated sheet, and multiple pre-impregnated sheets are laid according to the planned position and angle in turn, and the laying process adopts heating roller to compact, to form patch reinforcement layer;

[0015] Step seven, cylinder liner circumferential winding: the cylinder liner with completed local reinforcement layer is transferred to winding machine to carry out multi-layer circumferential winding in barrel area, to form annular winding layer;

[0016] Step eight, cylinder liner spiral winding: low-angle spiral winding is carried out outside annular winding layer and patch reinforcement layer, to form spiral winding layer;

[0017] Step nine, heating and curing: the cylinder liner with completed spiral winding layer is placed in curing oven, and heating and curing are carried out according to the set pre-curing-curing curve;

[0018] Step ten, test: the composite material cylinder liner after heating and curing is subjected to water pressure test and air tightness detection.

[0019] Preferably, in the step one, the plasma power is set to 300-400 W, the processing time is set to 3-5 min, the processing distance is controlled to 8-12 mm, and the surface roughness of the gas cylinder liner is controlled to 0.8-1.2 μm.

[0020] Preferably, in the step three, for the high stress area, i.e. the area with stress value not less than 80% of the design allowable stress, 4-6 layers of prepreg are planned to be laid; for the medium stress area, i.e. the area with stress value of 50%-80% of the design allowable stress, 2-3 layers of prepreg are planned to be laid; for the low stress area, i.e. the area with stress value not greater than 50% of the design allowable stress, 1-2 layers of prepreg are planned to be laid; the prepreg is in the shape of a fan or a trapezoid, with length ranging from 180 to 250 mm and width ranging from 35 to 60 mm; the layup angle of the prepreg includes 0°, ±45°.

[0021] Preferably, in the step four, the six-axis robot patching equipment is integrated with carbon fiber tape unwinding, laser cutting, visual positioning, weight detection and laying functions, the laser cutting function is completed by a laser cutting module, the visual positioning function is completed by a camera, the weight detection function is completed by an electronic scale, the unwinding speed of the six-axis robot patching equipment is set to range from 0.2 to 0.5 m / min, the laser cutting power is set to range from 50 to 80 W, the cutting accuracy is controlled to ±0.1 mm, the positioning accuracy of the visual positioning system is ±0.05 mm, and the movement speed of the mechanical arm is set to range from 0.3 to 0.8 m / s.

[0022] Preferably, in the step six, the overlap width of adjacent two layers of prepreg is 10-15 mm, and the overlap is arranged staggered to avoid stress concentration.

[0023] Preferably, in the step seven, a numerical control fiber winding machine is used to perform multi-layer hoop winding on the gas cylinder liner with the completed local reinforcing layer, the winding tension is set to 8-10 N before the winding operation, the winding speed is 1.2-2 m / s, the wire nozzle moving speed is 60-100 r / min, the single-layer thickness of the hoop winding layer is 0.5-0.6 mm, and the number of layers is 8-12.

[0024] Preferably, the hoop winding layer directly covers and compresses the local reinforcing layer, the carbon fibers are uniformly arranged without crossing and overlapping during the winding process, and the entire gas cylinder is covered.

[0025] Preferably, in the step eight, the spiral winding angle of the low-angle spiral winding is set between 10-15° or -15--10°, the winding tension is set between 5-8 N, the winding speed is set between 1.0-1.2 m / s, the spiral winding layer single-layer thickness is set between 0.5-0.6 mm, and the layer number is set between 5-25 layers.

[0026] Preferably, in the step nine, the pre-curing-curing curve is specifically that the temperature is raised from room temperature to 80-90℃ at a temperature raising rate of 20-30℃ / h, and the temperature is kept for 3-5 h, then the temperature is raised from 80-90℃ to 120-130℃ at a temperature raising rate of 50-60℃ / h, and then the temperature is naturally cooled to room temperature.

[0027] Preferably, in the step ten, the water pressure test pressure is 1.5 times of the design working pressure, the pressure maintaining time is at least 30 s, the gas cylinder body should not leak or be obviously deformed, and the leakage amount of the air tightness test should be no more than 6 ML / (h*L).

[0028] In the present application, a new gas cylinder shoulder reinforcing process route of automatic local patching + winding integration + integrated curing is proposed. The gas cylinder shoulder reinforcing body is formed by synchronously curing the un-cured prepreg sheet after winding lamination, and there is no secondary adhesive interface between the reinforcing body and the inner liner and the winding layer, realizing the structural integrity. Through the core design of replacing the global spiral winding with the local patching, the reinforcing material is only used in the bottle shoulder area which needs the most reinforcement, avoiding the fiber redundancy in the middle section of the cylinder body. Compared with the traditional more than thirty layers of spiral winding and the layer optimization scheme of CN115355439A, the carbon fiber usage can be reduced by 10%-20%, directly bringing significant raw material cost reduction and gas cylinder weight reduction.

[0029] The prepreg sheet is directly pasted in the un-cured state, and finally integrally cured at one time, completely eliminating the weak interface generated by independent curing and secondary adhesion, so that the gas cylinder shoulder reinforcing layer is tightly combined with the main winding layer, solving the interface hidden danger of CN120363445A and other technologies, and greatly improving the fatigue life, impact resistance and long-term air tightness reliability of the gas cylinder.

[0030] The six-axis robot patching equipment is an integrated patching equipment, realizing the full-process automation from cutting to laying, seamlessly connecting with the winding process, simplifying the production process, and saving the independent mold manufacturing, reinforcing patch winding, independent curing, cutting and other complex processes. Compared with the full winding process of CN115164089A, the production rhythm is faster and the consistency is better.

[0031] Based on stress cloud diagrams, CAD drawings of plastic inner liners with valve seats, and winding process parameters of gas cylinders, prepreg sheets of different sizes, shapes, and layup sequences can be freely designed to achieve on-demand reinforcement and optimize material distribution. This is something that traditional uniform spiral winding and the overall layup optimization and fixed-shape independent reinforcing sheets of CN115355439A cannot achieve.

[0032] The innovation in the process of attaching the gas cylinder shoulder at the front end allows for the continued use of existing winding machines and curing ovens at the back end, making it easy to modify and integrate into existing Type IV gas cylinder production lines, thus minimizing obstacles to industrialization.

[0033] This invention reduces carbon fiber material waste, precisely reinforces weak areas on the cylinder shoulder, improves the cylinder's load-bearing capacity, and simultaneously reduces the cylinder's thickness and weight. It balances airtightness, interfacial bonding, and fatigue life, solving the technical problems of excessive carbon fiber waste, insufficient reinforcement precision, and poor balance between load-bearing capacity and weight in the reinforcement of the cylinder shoulder of carbon fiber fully wound composite gas cylinders in the prior art. Attached Figure Description

[0034] Fig. 1 This is a schematic diagram of the overall structure of the carbon fiber fully wound gas cylinder of the present invention;

[0035] Fig. 2 This is a partially enlarged schematic diagram of the shoulder area of ​​the bottle of the present invention;

[0036] Fig. 3 This is a magnified schematic diagram of a portion of the enhanced patch area of ​​the present invention;

[0037] In the diagram: 1. Valve seat; 2. Gas cylinder liner; 3. Patch reinforcement layer; 4. Annular winding layer; 5. Spiral winding layer; 20. Cylinder body; 21. Cylinder shoulder. Detailed Implementation

[0038] The present invention will be further described below with reference to the accompanying drawings:

[0039] like Figs. 1-3 The invention illustrates a method for fully wound carbon fiber reinforcement at the shoulder of a gas cylinder liner. The gas cylinder liner 2 includes a cylinder body 20 and two shoulders 21. Stress concentration occurs due to abrupt curvature changes at the shoulders 21. A patch reinforcement layer 3 is provided at the shoulders 21, and an annular winding layer 4 is provided at the cylinder body 20. The annular winding layer 4 and the patch reinforcement layer 3 are seamlessly connected. A spiral winding layer 5 is provided outside the annular winding layer 4 and the patch reinforcement layer 3. The annular winding layer 4 and the spiral winding layer 5 together constitute a carbon fiber composite winding layer.

[0040] The method includes the following steps:

[0041] Step one, gas cylinder liner 2 pretreatment: adopt plasma treatment process to gas cylinder liner 2; In this case, the plasma power is set to 300-400W, the processing time is set to 3-5min, the processing distance is controlled to 8-12mm, the surface roughness of gas cylinder liner 2 is controlled to 0.8-1.2μm, the surface oil stain, impurity is removed and the surface activity is improved, the binding force with subsequent prepreg and winding layer is enhanced.

[0042] Step two, gas cylinder stress analysis: based on the gas cylinder design load and the three-dimensional model of the gas cylinder liner 2, the stress simulation analysis is carried out by using ANSYS finite element analysis software, the stress distribution of the gas cylinder is solved, and the local prepreg position of the bottle shoulder 21 is determined.

[0043] Step three, gas cylinder patch planning: based on the stress distribution results, combined with the gas cylinder liner 2 model with valve seat 1 and the winding process parameters such as winding layer, winding direction and winding speed, the CAM of the patch system is used for simulation and modeling to plan the laying position, prepreg size, layer angle and layer number of the prepreg of the bottle shoulder 21. For high stress area, i.e. the area with stress value not less than 80% of design allowable stress, 4-6 layers of prepreg are planned to be laid; for medium stress area, i.e. the area with stress value of 50%-80% of design allowable stress, 2-3 layers of prepreg are planned to be laid; for low stress area, i.e. the area with stress value not greater than 50% of design allowable stress, 1-2 layers of prepreg are planned to be laid; the shape of the prepreg is fan-shaped or trapezoidal, the length range is 180-250mm, the width range is 35-60mm; the layer angle of the prepreg includes 0°, ±45°. 0° layer is used to bear axial stress, and ±45° layer is used to bear shear stress.

[0044] Step four, gas cylinder liner 2 clamping: the pretreated gas cylinder liner 2 is positioned and clamped on the six-axis robot patch equipment;

[0045] The six-axis robot patch equipment integrates carbon fiber tape unwinding, laser cutting, visual positioning, weight detection and laying functions in one, the laser cutting function is completed by laser cutting module, the visual positioning function is completed by camera, the weight detection function is completed by electronic scale, the unwinding speed of the six-axis robot patch equipment is set to 0.2-0.5m / min, the laser cutting power is set to 50-80W, the cutting accuracy is controlled to ±0.1mm, the positioning accuracy of the visual positioning system is ±0.05mm, and the movement speed range of the mechanical arm is set to 0.3-0.8m / s.

[0046] Step five, prepreg cutting: carbon fiber and epoxy resin prepreg unidirectional tape is connected to the six-axis robot patching equipment, and the required prepreg is accurately cut online according to the planned prepreg size and shape through a laser cutting module. Nitrogen is used for protection during the cutting process, and the cut prepreg is quickly positioned and weighed. The nitrogen flow is 5-8 L / min to prevent the edge resin of the prepreg from burning. The weight deviation needs to be controlled within ±3%.

[0047] Step six, local prepreg laying: the six-axis robot patching equipment establishes a coordinate system by identifying the reference mark of the bottle shoulder 21 through visual positioning, controls the vacuum chuck to accurately clamp the qualified prepreg, and lays the multiple prepregs according to the planned position and angle. During the laying process, a heated roller is used for compaction to form the patch reinforcement layer 3. The overlap width of the adjacent two layers of prepregs is 10-15 mm, and the overlap is arranged staggered to avoid stress concentration. The roller temperature is set to 40-60°C, the pressure is 0.2-0.4 MPa, and the roller speed is 5-10 r / min to ensure that the prepreg is tightly attached to the inner liner curved surface without air bubbles, wrinkles, and edge lifting.

[0048] Step seven, circumferential winding of the cylinder inner liner 2: the cylinder inner liner 2 with the local reinforcement layer is transferred to the winding machine for multi-layer circumferential winding in the barrel 20 area to form the annular winding layer 4. Specifically, the cylinder inner liner 2 with the local reinforcement layer is subjected to multi-layer circumferential winding by using a numerical control fiber winding machine. The winding tension is set to 8-10 N before the winding operation, the winding speed is 1.2-2 m / s, the filament nozzle moving speed is 60-100 r / min, the single-layer thickness of the annular winding layer 4 is 0.5-0.6 mm, and the number of layers is 8-12 layers, which is determined according to the design thick wall and bearing requirements of the cylinder. The circumferential winding layer directly covers and compresses the local reinforcement layer. During the winding process, the carbon fibers are uniformly distributed without crossing and overlapping, covering the entire cylinder.

[0049] Step eight, spiral winding of the cylinder inner liner 2: low-angle spiral winding is performed outside the annular winding layer 4 and the patch reinforcement layer 3 to balance part of the axial stress, forming the spiral winding layer 5. The spiral winding angle of the low-angle spiral winding is set to 10-15° or -15 to -10°, the winding tension is set to 5-8 N, the winding speed is set to 1.0-1.2 m / s, the single-layer thickness of the spiral winding layer 5 is set to 0.5-0.6 mm, and the number of layers is set to 5-25 layers. During the winding process, the numerical control system of the winding machine accurately controls the winding angle and pitch to ensure that the fibers are uniformly distributed in the barrel 20 and bottle shoulder 21 area.

[0050] Step nine, heating and curing: the completed spiral wound layer 5 of the cylinder liner 2 is placed in a curing oven, and heated and cured according to the set pre-curing-curing curve; the temperature is raised from room temperature to 80-90°C at a rate of 20-30°C / h, and held for 3-5h, then raised from 80-90°C to 120-130°C at a rate of 50-60°C / h, and held for 3-5h, and then naturally cooled to room temperature.

[0051] Step ten, test: the composite cylinder liner 2 after heating and curing is subjected to a water pressure test and a gas tightness test. The water pressure test pressure is 1.5 times the design working pressure, and the pressure holding time is at least 30s, and the cylinder body should not leak or deform significantly; the gas tightness test leakage should be no more than 6ML / (h*L).

[0052] Example one: taking the manufacture of a 35MPa-390L type IV cylinder for hydrogen storage as an example

[0053] The HDPE liner is subjected to plasma treatment with a plasma power of 350 W, a treatment time of 4 min, and a treatment distance of 10 mm, and the surface roughness reaches Ra 1.0 μm. The load boundary conditions are: working pressure 35 MPa, allowable pressure 43.75 MPa, water pressure test pressure 52.5 MPa, and minimum burst pressure 78.75 MPa. Through ANSYS finite element analysis, it is determined that each of the two bottle shoulders 21 of the cylinder liner 2 needs to be laid with four layers of T700 carbon fiber / epoxy resin prepreg unidirectional tape (areal density 180 g / m2, resin content 40%), of which two layers are ±45° laid larger size pieces (230 mm x 55 mm) covering the main stress area, and two layers are 0° laid small size pieces (180 mm x 35 mm) for local reinforcement. The cylinder liner 2 is fixed on the six-axis robot patching equipment, and the unwinding speed is set to 0.3 m / min, the laser cutting power is 60 W, the visual positioning accuracy is ±0.05 mm, and the mechanical arm movement speed is 0.5 m / s. The equipment pulls out 300 mm wide prepreg tape from the roll, cuts the corresponding shape of the sheet, and after passing the visual detection and weight detection, picks up by the end suction cup (diameter 18 mm, vacuum degree -0.07 MPa) of the six-axis robot patching equipment, and lays accurately on the shoulder of the cylinder liner 2 under the visual guidance, and uses a heating press roller (temperature 50℃, pressure 0.3 MPa, speed 8 r / min) to compact. Repeat this process until all eight layers (four layers for each of the two bottle shoulders 21) are laid, the overlapping width of adjacent two layers is 12 mm, and the time consumption is 32 minutes. The cylinder liner 2 is moved to the winding machine, and first, ten layers of hoop winding (T700-24K carbon fiber / epoxy resin wet winding, resin system content 30%) is performed, the winding tension is 9 N, the winding speed is 1.0 m / s (1.2-2 m / s), the wire nozzle moving speed is 72 r / min, the ring winding layer 4 single layer thickness is 0.6 mm, and the cylinder body 20 is completely covered. Subsequently, eight layers of low angle spiral winding with an angle of ±12° is performed, the winding tension is 8 N, the winding speed is 1.2 m / s (1.0-1.2 m / s), the spiral winding layer 5 single layer thickness is 0.8 mm (0.5-0.6 mm), and the entire area of the cylinder liner 2 is covered. The cylinder liner 2 is placed in a curing oven and cured according to the pre-curing-curing curve: from room temperature to 75℃ at a rate of 20℃ / h, holding for 3 h; then from 75℃ to 120℃ at a rate of 60℃ / h, holding for 4 h; and finally naturally cooled to room temperature (cooling rate ≤25℃ / h). Then, the water pressure test is performed at a test pressure of 52.5 MPa (35 MPa x 1.5), holding for 1 min, and then the air tightness test is performed: the leakage amount is ≤6 ML / (h*L), and the test is qualified.

[0054] Compared with the benchmark product using traditional 16-layer spiral winding + 13-layer hoop winding, the total amount of carbon fiber of the gas cylinder of the embodiment is reduced by about 18%, and the weight of the finished product is reduced by about 10%. Water pressure blasting test and fatigue test (cycle under 78.75 MPa pressure) show that the blasting pressure meets the standard (≥87.5 MPa), and the fatigue life is improved by more than 20%.

[0055] Example II: 20 MPa stress level type IV cylinder, simplified variant

[0056] The plasma treatment process of example I is used, and through finite element analysis, it is determined that three layers of prepreg sheets (two layers of ±45° layup and one layer of 0° layup) are planned to be laid in the shoulder area 21, with a size of 200 mm x 45 mm. The equipment parameters are set as in example I, and the laying of the three layers of prepreg sheets is completed, with an overlapping width of 10 mm between adjacent two layers. The spiral winding step is cancelled, and only ten layers of hoop winding are performed (parameters same as example I), and the strong clamping force generated by the hoop winding firmly integrates the patch area of the shoulder 21. The curing process and post-processing process of example I are used.

[0057] This method further simplifies the process and is suitable for occasions where the axial load requirement is not extremely harsh. Compared with the full winding process of CN115164089A, the carbon fiber consumption is reduced by about 15%, the finished product weight is reduced by about 8%, the cost and efficiency advantages are more obvious, the blasting pressure is ≥50 MPa, and the fatigue life meets the requirements of relevant standards.

[0058] The above examples are only a number of descriptions of the concept and implementation of the present application, and do not limit it. Under the concept of the present application, technical solutions without substantial changes are still within the protection scope.

Claims

1. A method for fully wound carbon fiber reinforcement at the shoulder of a gas cylinder liner, wherein the gas cylinder liner includes a cylinder body and two shoulders, and stress concentration occurs due to abrupt curvature change at the shoulders, characterized in that: A patch reinforcement layer is provided at the shoulder of the bottle, and an annular winding layer is provided at the body of the cylinder. The annular winding layer and the patch reinforcement layer are seamlessly connected. A spiral winding layer is provided outside the annular winding layer and the patch reinforcement layer. The annular winding layer and the spiral winding layer together constitute a carbon fiber composite winding layer. The method includes the following steps: Step 1: Pre-treatment of the gas cylinder liner; Step 2, Cylinder Stress Analysis: Based on the cylinder design load and the three-dimensional model of the cylinder liner, stress simulation analysis is performed using ANSYS finite element analysis software to solve for the cylinder stress distribution and determine the location of the prepreg sheet to be laid locally at the cylinder shoulder. Step 3, Gas Cylinder Patch Planning: Based on the stress distribution results, use CAD-CAM software to plan the application location, size, shape, layup angle, and number of layers of the prepreg sheets; Step 4: Gas cylinder liner installation: Position and install the pre-treated gas cylinder liner onto the six-axis robot patching equipment; Step 5, Prepreg Sheet Cutting: Connect the carbon fiber and epoxy resin prepreg unidirectional tape to the six-axis robot patching equipment, cut the required prepreg sheets according to the planned prepreg sheet size and shape, and perform rapid visual positioning and weight detection on the cut prepreg sheets. Step 6: Partial Prepreg Laying: The six-axis robot laying equipment picks up qualified prepreg sheets and lays multiple prepreg sheets in sequence according to the planned position and angle. During the laying process, heated pressure rollers are used to compact the sheets to form a patch reinforcement layer. Step 7: Circumferential winding of the cylinder liner: The cylinder liner with the completed local reinforcement layer is transferred to the winding machine for multi-layer circumferential winding of the cylinder body area to form a ring winding layer; Step 8, Spiral winding of the gas cylinder liner: Low-angle spiral winding is performed outside the annular winding layer and the patch reinforcement layer to form a spiral winding layer; Step 9, Heating and Curing: Place the gas cylinder liner with the completed spiral winding layer into the curing oven and heat and cure it according to the set pre-curing-curing curve; Step 10, Testing: Conduct a water pressure test and airtightness test on the composite material gas cylinder liner after heat curing.

2. The method for fully winding carbon fiber reinforced with a patch at the shoulder of the gas cylinder liner according to claim 1, characterized in that: In step one, the plasma power is set to 300-400W, the processing time is set to 3-5min, the processing distance is controlled at 8-12mm, and the surface roughness of the gas cylinder liner is controlled at 0.8-1.2μm.

3. The method for fully winding carbon fiber reinforced with a patch at the shoulder of the gas cylinder liner according to claim 1, characterized in that: In step three, for high-stress areas (i.e., areas with stress values ​​not less than 80% of the design allowable stress), 4 to 6 layers of prepreg are planned to be laid; for medium-stress areas (i.e., areas with stress values ​​of 50% to 80% of the design allowable stress), 2 to 3 layers of prepreg are planned to be laid; for low-stress areas (i.e., areas with stress values ​​not greater than 50% of the design allowable stress), 1 to 2 layers of prepreg are planned to be laid. The prepreg sheets are fan-shaped or trapezoidal in shape, with a length ranging from 180 to 250 mm and a width ranging from 35 to 60 mm. The layup angle of the prepreg sheets includes 0° and ±45°.

4. The method for fully winding carbon fiber reinforced with a patch at the shoulder of the gas cylinder liner according to claim 1, characterized in that: In step four, the six-axis robot patching equipment integrates carbon fiber tape unwinding, laser cutting, vision positioning, weight detection, and patching functions. The laser cutting function is completed by the laser cutting module, the vision positioning function is completed by the camera, and the weight detection function is completed by the electronic scale. The unwinding speed of the six-axis robot patching equipment is set within the range of 0.2 to 0.5 m / min, the laser cutting power is set within the range of 50 to 80 W, the cutting accuracy is controlled within ±0.1 mm, the positioning accuracy of the vision positioning system is ±0.05 mm, and the movement speed of the robotic arm is set within the range of 0.3 to 0.8 m / s.

5. The method for fully winding carbon fiber reinforced with a patch at the shoulder of the gas cylinder liner according to claim 1, characterized in that: In step six, the overlap width of two adjacent prepreg sheets is 10-15 mm, and the overlaps are staggered to avoid stress concentration.

6. The method for fully winding carbon fiber reinforced with a patch at the shoulder of the gas cylinder liner according to claim 1, characterized in that: In step seven, a CNC fiber winding machine is used to perform multi-layer circumferential winding on the gas cylinder liner that has completed the local reinforcement layer. Before the winding operation, the winding tension is set to 8-10N, the winding speed is 1.2-2m / s, the winding nozzle moving speed is 60-100r / min, the thickness of a single layer of the annular winding layer is 0.5-0.6mm, and the number of layers is 8-12.

7. The method for fully winding carbon fiber reinforced with a patch at the shoulder of a gas cylinder liner according to claim 6, characterized in that: The circumferential winding layer directly covers and compresses the local reinforcing layer. During the winding process, the carbon fibers are evenly distributed without crossing or overlapping, covering the entire gas cylinder.

8. The method for fully winding carbon fiber reinforced with a patch at the shoulder of a gas cylinder liner according to claim 1, characterized in that: In step eight, the spiral winding angle of the low-angle spiral winding is set between 10 and 15° or -15 to -10°, the winding tension is set between 5 and 8 N, the winding speed is set between 1.0 and 1.2 m / s, the thickness of a single spiral winding layer is set between 0.5 and 0.6 mm, and the number of layers is set between 5 and 25.

9. The method for fully winding carbon fiber reinforced with a patch at the shoulder of a gas cylinder liner according to claim 1, characterized in that: In step nine, the pre-curing-curing curve is specifically as follows: the temperature is increased from room temperature to 80-90°C at a heating rate of 20-30°C / h and held for 3-5 hours. After the holding period, the temperature is increased from 80-90°C to 120-130°C at a heating rate of 50-60°C / h and held for 3-5 hours, and then naturally cooled to room temperature.

10. The method for fully winding carbon fiber reinforced with a patch at the shoulder of a gas cylinder liner according to claim 1, characterized in that: In step ten, the water pressure test pressure is 1.5 times the design working pressure, the pressure holding time is at least 30 seconds, and the gas cylinder body should not leak or be obviously deformed; the leakage of the airtightness test should not be greater than 6 ml / (h*L).

Images