Composite material air cylinder and manufacturing method

Abstract

The invention discloses a composite material air cylinder and a manufacturing method, the composite material air cylinder comprises an inner container (110) and a winding layer (120), the inner container comprises an inner container body (111) and a metal pipe seat (112), and the winding layer (120) comprises a spiral winding layer (121) and an annular winding layer (122); the metal tube base (112) and the inner container body (111) are of an integrally-formed structure, the winding layer (120) is made of carbon fibers, and the multiple spiral winding layers (121) and the multiple annular winding layers are alternately wound on the outer surface of the inner container (110) and are mutually cured and bonded through resin; a metal tube seat (112) is formed through machining, the metal tube seat (112) is placed on a rotational molding mold of the inner container body (111), and the inner container (110) is obtained through a rotational molding process; the inner container (110) is fixed, the multiple spiral winding layers (121) and the multiple annular winding layers (122) which are soaked with the resin are wound on the surface of the inner container (110), and finally protective paint is sprayed on the surface of the cured air cylinder.

Description

Technical Field

[0001] The invention relates to the field of rail vehicle parts manufacturing, and in particular to a composite material air cylinder and a manufacturing method thereof. Background Art

[0002] The air cylinder is a storage container for compressed air and an indispensable part of the air brake system. It is responsible for the total air storage and auxiliary air storage of the brake system. As a low-pressure container, the working pressure of the air cylinder is 10 bar and the working temperature is -50℃-70℃. The volume and size of the air cylinder vary according to different vehicle models, and are generally above 100L. Traditional rail vehicle air cylinders are mainly made of steel and aluminum alloy, and are made of a rolled cylinder and two end heads welded together. However, during welding, welding deformation and pores will appear on the surface, and defects such as unfusion and inclusions will appear inside. In addition, metal air cylinders also have problems such as heavy weight, fatigue resistance, inconvenient installation, and the need for regular painting and anti-corrosion treatment.

[0003] With the rapid development of rail transit, the huge increase in energy consumption has led to increasingly serious environmental problems, and reducing vehicle weight has become an increasingly urgent issue. Existing rail vehicle air cylinders are all made of metal. For example, the material of the high-speed rail air cylinder is aluminum alloy, and the material of the subway air cylinder is carbon steel. Their weight is relatively large, which is not conducive to the speed increase and energy saving of rail transit vehicles. Therefore, it is necessary to achieve the purpose of reducing the weight of the air cylinder through material improvement.

[0004] In order to deal with the problems in the field of air cylinder manufacturing, in recent years, new materials and manufacturing technologies have been explored to reduce the weight of air cylinders while maintaining or improving their performance. Carbon fiber composite materials have become an ideal choice for manufacturing lightweight air cylinders due to their light weight and high strength. The application of this material can not only significantly reduce the weight of the air cylinder, but also provide better corrosion resistance and temperature resistance, thereby improving the overall performance and service life of the air cylinder.

[0005] Patent document CN218522967U discloses a novel air cylinder liner made of carbon fiber composite material, including an liner body, an intermediate metal part, a head end metal part, and an external metal part. The liner body includes a blow molded part cylinder and an injection molded part. The injection molded part is a fixing part used to cooperate with the head end metal part; the blow molded part cylinder forms an integral structure with the injection molded part during the blow molding process, a vent hole is provided in the middle of the injection molded part, the head end metal part is connected to the injection molded part by threaded connection or gluing, the external metal part is threadedly connected to the head end metal part, and the external metal part is provided with a protruding into the injection molded part. The sealing part of the air vent of the blow-molded part has a sealing ring installed between the sealing part and the injection molded part; a protruding hollow connecting column is provided on the side wall of the blow-molded part cylinder, and the intermediate metal part is sleeved on the above hollow connecting column, and is connected by a later gluing process. However, the performance of the air cylinder liner manufactured by the blow molding process, including tensile strength, elongation at break and notch impact strength, are different from those of the one-piece molded structure air cylinder liner obtained by the rotational molding process. At the same time, there is room for improvement in manufacturing efficiency and designability. This solution does not solve the problems of wall thickness uniformity, durability and thermal stability caused by the blow molding process of the air cylinder liner.

[0006] Patent document CN114383037B discloses a method for preparing a carbon fiber composite air cylinder, including the steps of making an inner liner, making a pressure-bearing layer, making a protective layer, curing and molding, installing a handle, and surface treatment. The inner liner and the pipe seat are blow-molded together at one time, and then the pressure-bearing layer and the protective layer are wound around the outer side of the inner liner in sequence. During the winding, a spike is designed on the pipe seat to smoothly slide the continuous fiber to both sides of the pipe seat, thereby achieving process continuity. After the composite material layer is cured, the handle is polished and glued, and the handle is hand-paste reinforced. However, the problems of wall thickness uniformity, durability, and thermal stability caused by the blow molding process of the air cylinder inner liner are not solved.

[0007] In summary, the above two existing patents do not solve the problems of wall thickness uniformity, durability and thermal stability caused by the blow molding process of the air cylinder liner. Summary of the invention

[0008] Based on the above technical problems, the present invention proposes a composite material air cylinder and a manufacturing method to solve the problems of wall thickness uniformity, durability and thermal stability caused by the blow molding process of the air cylinder liner in the prior art.

[0009] To achieve the above object, the present invention provides a composite material air cylinder.

[0010] A composite material air cylinder, comprising:

[0011] An inner liner and a winding layer, wherein the inner liner includes an inner liner body and a plurality of metal tube seats, and the winding layer includes a plurality of spiral winding layers and a plurality of annular winding layers;

[0012] The metal tube seat and the inner liner body are an integrally formed structure, the material of the winding layer is carbon fiber, the multiple layers of the spiral winding layers and the multiple layers of the annular winding layers are alternately wound on the outer surface of the inner liner, the multiple layers of the spiral winding layers and the multiple layers of the annular winding layers are bonded to the surface of the inner liner by resin, and are cured and bonded to each other by the resin.

[0013] Furthermore, the wall thickness of the inner tank body is 2mm-3mm.

[0014] Furthermore, the material of the inner liner body is high-density polyethylene roto-plastic or nylon roto-plastic.

[0015] Furthermore, the metal pipe seat includes an intake pipe seat and an exhaust pipe seat.

[0016] Furthermore, the resin includes epoxy resin, and the air cylinder also includes an additive, and the additive is one or more of a halogen-free low-smoke flame retardant, an anti-UV aging agent, and a toughening agent.

[0017] Furthermore, the thickness of the winding layer is 1.44 mm-1.56 mm.

[0018] Furthermore, the angle formed between the multiple layers of the hoop-wound layers and the axial direction of the inner container is 88°-92°;

[0019] The angle formed between the multiple spirally wound layers and the axial direction of the inner container is 19°-21° or 159°-161°.

[0020] Further, the winding layer is composed of three windings, the winding group includes a circumferential winding group and a spiral winding group, the circumferential winding group includes multiple layers of the circumferential winding layer, and the spiral winding group includes multiple layers of the spiral winding layer;

[0021] Starting from the surface of the inner container, the winding layer is composed of the annular winding group, the spiral winding group and the annular winding group from the inside to the outside.

[0022] Furthermore, the plurality of circumferential winding layers in the circumferential winding group are alternately placed at 89±1° and 91±1° axially of the inner liner, and the thickness of each circumferential winding layer is 0.12mm-0.13mm;

[0023] The multiple layers of the spiral winding layer in the spiral winding group are alternately placed at 20±1° and 160±1° axially of the inner liner, and the thickness of each spiral winding layer is 0.12mm-0.13mm.

[0024] Furthermore, the ratio of the number of layers of the circumferential winding layer to the number of layers of the spiral winding layer in the winding group is 2:1.

[0025] Furthermore, the ratio of the number of layers of the circumferential winding layer in the circumferential winding group to the number of layers of the spiral winding layer in the spiral winding group is 1:1.

[0026] To achieve the above object, the present invention also provides a method for manufacturing a composite material air cylinder.

[0027] A method for manufacturing a composite material air cylinder, comprising:

[0028] S1: forming the metal tube seat by machining, placing the metal tube seat on a rotational molding mold of the inner liner body, and obtaining the inner liner by a rotational molding process;

[0029] S2: fixing the inner liner, and winding the multiple spiral winding layers and the multiple hoop winding layers soaked with the resin on the surface of the inner liner;

[0030] S3: spraying protective paint on the surface of the cured air cylinder.

[0031] Furthermore, the step S1 includes:

[0032] The rotational molding mold of the inner container body is placed in a heating chamber for heating, and simultaneously performs revolution and rotation along the main and secondary axes perpendicular to each other in the heating chamber while heating.

[0033] Furthermore, the step S1 further includes:

[0034] The temperature of the heating chamber is 250°C-260°C.

[0035] Furthermore, the step S1 further includes:

[0036] The inner surface of the rotational molding mold of the liner body is coated with a release agent.

[0037] Furthermore, the step S1 further includes:

[0038] The release agent includes one or more of oleic acid, paraffin and zinc stearate.

[0039] Furthermore, the step S1 further includes:

[0040] The rotationally molded inner liner is demoulded, and the surface of the inner liner is sandblasted.

[0041] Furthermore, the step S2 further includes:

[0042] The material carbon fiber of the winding layer is impregnated with resin.

[0043] Furthermore, the step S2 further includes:

[0044] The inner container is fixed on the rotating shaft of the winding machine.

[0045] Furthermore, the step S2 includes:

[0046] Winding a layer of the circumferential winding layer at a position of 89±1° in the axial direction of the air cylinder, then winding a layer of the circumferential winding layer at a position of 91±1° in the axial direction of the air cylinder, and repeating the above steps of winding a layer of the circumferential winding layer until a set of circumferential winding groups is completed;

[0047] Winding a layer of the spiral winding layer at a position of 20±1° in the axial direction of the air cylinder, then winding a layer of the spiral winding layer at a position of 160±1° in the axial direction of the air cylinder, and repeating the above step of winding a layer of the spiral winding layer until a set of spiral winding groups is completed;

[0048] After the spiral winding group is completed, a group of the annular winding group is repeated again until the thickness of the winding layer reaches 1.44mm-1.56mm.

[0049] Furthermore, the step S2 includes:

[0050] After completing each layer of the circumferential winding layer (122) or the spiral winding layer (121), when winding the next layer of the circumferential winding layer (122) or the spiral winding layer (121), the tension applied by the winding machine is reduced by 5N.

[0051] Furthermore, the step S2 further includes:

[0052] The inner container wrapped with the wrapping layer is placed in an oven for curing, and the curing temperature in the oven is 100° C.-120° C.

[0053] Furthermore, after step S2, the method further includes:

[0054] The surface of the air cylinder after solidification is polished.

[0055] Furthermore, the step S3 includes:

[0056] The protective paint is acrylic polyurethane.

[0057] Based on the above technical solution, the present invention has at least the following beneficial effects:

[0058] 1. The present invention proposes a composite air cylinder and a manufacturing method, which improves the product design flexibility of the composite air cylinder through the rotational molding process, and can manufacture products with complex, asymmetric or irregular shapes, which are often difficult to achieve in the blow molding process. When the air cylinder is manufactured by the rotational molding process, a variety of plastic materials such as polyethylene, polyvinyl chloride, nylon, etc. can be used. Compared with the blow molding process using specific materials such as PET or HDPE materials to manufacture the air cylinder, the air cylinder liner manufactured by the rotational molding process is more efficient and has better mechanical properties. The expanded range of material selection also enables rotational molding to adapt to a wider range of air cylinder production needs.

[0059] 2. The composite air cylinder and manufacturing method proposed by the present invention can achieve more uniform wall thickness throughout the product through the rotational molding process, which is essential to ensure the structural integrity and performance of the product. Since there is less material waste and high material utilization during the rotational molding process, production costs are reduced and the impact on the environment is reduced. This efficient material use and uniform wall thickness control make the rotational molding process an ideal choice when manufacturing large products or products with specific strength requirements.

[0060] 3. The composite air cylinder and manufacturing method proposed in the present invention significantly improve the strength and durability of the overall structure through the design of alternating winding circumferential winding layers and spiral winding layers, further optimize the winding layering method, achieve higher bursting pressure and residual bursting pressure after cycling, and ensure stability under high pressure and cyclic loads. The alternating winding method effectively disperses stress, reduces the risk of delamination damage, and enhances material utilization and structural balance performance. These improvements not only improve the load-bearing capacity of the air cylinder, but also ensure long-term reliability and safe operation, which is crucial to ensuring the safety and performance of rail vehicles.

[0061] 4. The composite air cylinder and manufacturing method proposed in the present invention achieves the optimization of material use by precisely controlling the winding angle and tension, as well as reasonable material distribution, which reduces weight and further reduces material waste, and is of great significance for improving the energy efficiency and dynamic performance of rail vehicles. Lightweight design also helps to reduce energy consumption and environmental impact, and meets the requirements of modern transportation for environmental protection and energy conservation. Through these technological innovations, the air cylinder not only improves its own performance, but also has a positive impact on the efficiency and economy of the entire rail vehicle system. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary 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 accompanying drawings:

[0063] Figure 1A schematic diagram of the structure of a composite material air cylinder according to an embodiment is shown.

[0064] The above-mentioned drawings include the following reference numerals:

[0065] 110, liner; 120, winding layer;

[0066] 111. Inner tank body; 112. Metal tube seat;

[0067] 121. spiral winding layer; 122. hoop winding layer. DETAILED DESCRIPTION

[0068] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0069] In the description, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0070] Example

[0071] The present invention provides a composite material air cylinder, such as Figure 1 Shown include

[0072] The inner liner 110 and the winding layer 120 , wherein the inner liner includes an inner liner body 111 and a plurality of metal tube seats 112 , and the winding layer 120 includes a plurality of spiral winding layers 121 and a plurality of annular winding layers 122 .

[0073] The metal tube seat 112 and the inner liner body 111 are an integrally formed structure. The material of the winding layer 120 is carbon fiber. The multiple layers of the spiral winding layer 121 and the multiple layers of the annular winding layer are alternately wound on the outer surface of the inner liner 110. The multiple layers of the spiral winding layer 121 and the multiple layers of the annular winding layer are bonded to the surface of the inner liner 110 by resin and are cured and bonded to each other by the resin.

[0074] Example 1

[0075] The thickness of the inner tank body 111 of the air cylinder is 2mm, the thickness of the circumferential winding layer is 0.12mm, the thickness of the spiral winding layer is 0.12mm, the thickness of the winding layer is 1.44mm, and the winding layer 120 is composed of 8 layers of circumferential winding layers 122 and 4 layers of spiral winding layers 121 from the surface of the inner tank 110 to the outside. The angles formed by the circumferential winding layer 122 and the axial direction of the inner tank 110 are 88° and 92°, and the angles formed by the spiral winding layer 121 and the axial direction of the inner tank 110 are 19° and 161°.

[0076] A composite material air cylinder manufacturing method in this embodiment includes:

[0077] Fix two metal tube seats 112 at the set positions in the metal rotational molding mold, apply a release agent to the inner cavity surface of the metal mold, add high-density polyethylene rotational plastic as material into the metal rotational molding mold, place the metal rotational molding mold in a heating chamber and heat it to 250°C, and simultaneously revolve and rotate along the mutually perpendicular main axis and secondary axis of the heating chamber, so that the material is evenly melted and deposited on the inner wall of the metal rotational molding mold. After the rotational molding is completed, wait for the metal rotational molding mold to cool to room temperature, take out the manufactured liner 110, sandblast it, and fix it on the rotating shaft of the winding machine after the sandblasting is completed; soak the carbon fiber in the resin, starting from the middle of the air cylinder. , 8 layers of annular winding layers 122 are wound alternately in a clockwise and counterclockwise manner at 88° and 92° positions of the air cylinder axis. After the winding of the annular winding layer 122 is completed, the middle of the air cylinder is used as the starting point, and 4 layers of spiral winding layers 121 are wound alternately in a clockwise and counterclockwise manner at 19° and 161° positions of the air cylinder axis. After each layer of winding is completed, the tension applied when winding the next layer is reduced by 5N. The winding is continued until the thickness of the winding layer 120 reaches 1.44mm. After the winding is completed, the air cylinder is placed in an oven and maintained at 100℃ for curing. After curing, the air cylinder is polished and finally sprayed with acrylic polyurethane protective paint.

[0078] Example 2

[0079] The thickness of the inner tank body 111 of the air cylinder is 3mm, the thickness of the circumferential winding layer is 0.13mm, the thickness of the spiral winding layer is 0.13mm, the thickness of the winding layer is 1.56mm, and the winding layer 120 is composed of the surface of the inner tank 110 from the inside to the outside. It can be firstly wound with 4 layers of spiral winding layers 121, and then wound with 8 layers of circumferential winding layers 122. The angles formed by the circumferential winding layer 122 and the axial direction of the inner tank 110 are 88° and 92°, and the angles formed by the spiral winding layer 121 and the axial direction of the inner tank 110 are 21° and 159°.

[0080] A composite material air cylinder manufacturing method in this embodiment includes:

[0081] Fix two metal tube seats 112 at the set positions in the metal rotational molding mold, apply a release agent to the inner cavity surface of the metal mold, add high-density polyethylene rotational plastic as material into the metal rotational molding mold, place the metal rotational molding mold in a heating chamber and heat it to 260°C, and simultaneously revolve and rotate along the mutually perpendicular main axis and secondary axis of the heating chamber, so that the material is evenly melted and deposited on the inner wall of the metal rotational molding mold. After the rotational molding is completed, wait for the metal rotational molding mold to cool to room temperature, take out the manufactured liner 110, sandblast it, and fix it on the rotating shaft of the winding machine after the sandblasting is completed; soak the carbon fiber in the resin, starting from the middle of the air cylinder. , four layers of annular winding layers 122 are wound alternately in a clockwise and counterclockwise manner at 88° and 92° positions of the air cylinder axis. After the winding of the annular winding layer 122 is completed, eight layers of spiral winding layers 121 are wound alternately in a clockwise and counterclockwise manner at 19° and 161° positions of the air cylinder axis from the middle of the air cylinder. After each layer of winding is completed, the tension applied to the next layer is reduced by 5N. The winding is continued until the thickness of the winding layer 120 reaches 1.56mm. After the winding is completed, the air cylinder is placed in an oven and maintained at 100°C for curing. After curing, the air cylinder is polished and finally sprayed with acrylic polyurethane protective paint.

[0082] Example 3

[0083] Preferably, the thickness of the inner tank body 111 of the air cylinder is 3 mm, the thickness of the circumferential winding layer is 0.125 mm, the thickness of the spiral winding layer is 0.125 mm, and the thickness of the winding layer is 1.5 mm. The winding layer 120 is composed of the surface of the inner tank 110 from the inside to the outside, and can be firstly wound with 4 layers of circumferential winding layers 122, then wound with 4 layers of spiral winding layers 121, and finally wound with 4 layers of circumferential winding layers 122. The angles formed by the circumferential winding layer 122 and the axial direction of the inner tank 110 are 89° and 91°, and the angles formed by the spiral winding layer 121 and the axial direction of the inner tank 110 are 20° and 160°, so that the ratio of the number of winding layers arranged in different directions in the winding layer 120 is 1:1:1.

[0084] A composite material air cylinder manufacturing method in this embodiment includes:

[0085] Fix two metal tube seats 112 at the set positions in the metal rotational molding mold, apply a release agent to the inner cavity surface of the metal mold, add high-density polyethylene rotational plastic as material into the metal rotational molding mold, place the metal rotational molding mold in a heating chamber and heat it to 255°C, and simultaneously revolve and rotate along the mutually perpendicular main axis and secondary axis of the heating chamber, so that the material is evenly melted and deposited on the inner wall of the metal rotational molding mold. After the rotational molding is completed, wait for the metal rotational molding mold to cool to room temperature, take out the manufactured liner 110, sandblast it, and fix it on the rotating shaft of the winding machine after the sandblasting is completed; soak the carbon fiber in the resin, take the middle of the air cylinder as the starting point, and rotate clockwise and counterclockwise at the 89° and 91° positions of the air cylinder axis respectively. 4 layers of annular winding layers 122 are wound in a manner, after the winding of the annular winding layer 122 is completed, the middle of the air cylinder is used as the starting point, and 4 layers of spiral winding layers 121 are wound alternately in a clockwise and counterclockwise manner at 20° and 160° positions of the air cylinder axial direction, and finally, the middle of the air cylinder is used as the starting point, and 4 layers of annular winding layers 122 are wound alternately in a clockwise and counterclockwise manner at 89° and 91° positions of the air cylinder axial direction, after each layer of winding is completed, the tension applied when winding the next layer is reduced by 5N, and the winding is continued until the thickness of the winding layer 120 reaches 1.5mm. After the winding is completed, the air cylinder is placed in an oven and maintained at 110℃ for curing. After curing, the air cylinder is polished and finally sprayed with acrylic polyurethane protective paint.

[0086] Example 4

[0087] The thickness of the inner tank body 111 of the air cylinder is 3mm, the thickness of the circumferential winding layer is 0.125mm, the thickness of the spiral winding layer is 0.125mm, and the thickness of the winding layer is 1.5mm. The winding layer 120 is composed of the surface of the inner tank 110 from the inside to the outside. It can be firstly wound with 2 layers of circumferential winding layers 122, then wound with 4 layers of spiral winding layers 121, and finally wound with 6 layers of circumferential winding layers 122. The angles formed by the circumferential winding layer 122 and the axial direction of the inner tank 110 are 89° and 91°, and the angles formed by the spiral winding layer 121 and the axial direction of the inner tank 110 are 20° and 160°.

[0088] A composite material air cylinder manufacturing method in this embodiment includes:

[0089] Fix two metal tube seats 112 at the set positions in the metal rotational molding mold, apply a release agent to the inner cavity surface of the metal mold, add high-density polyethylene rotational plastic as material into the metal rotational molding mold, place the metal rotational molding mold in a heating chamber and heat it to 255°C, and simultaneously revolve and rotate along the mutually perpendicular main axis and secondary axis of the heating chamber, so that the material is evenly melted and deposited on the inner wall of the metal rotational molding mold. After the rotational molding is completed, wait for the metal rotational molding mold to cool to room temperature, take out the manufactured liner 110, sandblast it, and fix it on the rotating shaft of the winding machine after the sandblasting is completed; soak the carbon fiber in the resin, take the middle of the air cylinder as the starting point, and rotate clockwise and counterclockwise at the 89° and 91° positions of the air cylinder axis respectively. 2 layers of annular winding layers 122 are wound in a manner, after the winding of the annular winding layer 122 is completed, four layers of spiral winding layers 121 are wound alternately in a clockwise and counterclockwise manner at 20° and 160° positions of the wind cylinder axis, starting from the middle of the wind cylinder, and six layers of annular winding layers 122 are wound alternately in a clockwise and counterclockwise manner at 89° and 91° positions of the wind cylinder axis, after each winding of any one of the winding layers is completed, the tension applied when winding the next layer decreases by 5N, and the winding is continued until the thickness of the winding layer 120 reaches 1.5mm. After the winding is completed, the wind cylinder is placed in an oven and maintained at 110°C for curing. After curing, the wind cylinder is polished and finally sprayed with acrylic polyurethane protective paint.

[0090] As shown in Table 1 below, the bursting pressure and residual bursting pressure data of different winding methods are as follows. The bursting pressure is the maximum pressure load that the air cylinder can withstand after the current winding method is completed and solidified. The residual bursting pressure is the maximum pressure load after the currently solidified air cylinder is subjected to 15,000 water hammer pressure cycles.

[0091] Table 1 Corresponding data of bursting pressure of different winding methods

[0092]

[0093]

[0094] In other embodiments, the winding layer 120 may be composed of 6 layers of the annular winding layers 122, 4 layers of the spiral winding layers 121 and 2 layers of the annular winding layers 122, 4 layers of the annular winding layers 122, 6 layers of the spiral winding layers 121 and 8 layers of the annular winding layers 122, etc., all of which can be used as the winding methods of the wind cylinder winding layer.

[0095] In summary, it can be seen from the above description that the above embodiments of the present invention achieve the following technical effects:

[0096] 1. The present invention proposes a composite air cylinder and a manufacturing method, which improves the product design flexibility of the composite air cylinder through the rotational molding process, and can manufacture products with complex, asymmetric or irregular shapes, which are often difficult to achieve in the blow molding process. When the air cylinder is manufactured by the rotational molding process, a variety of plastic materials such as polyethylene, polyvinyl chloride, nylon, etc. can be used. Compared with the blow molding process using specific materials such as PET or HDPE materials to manufacture the air cylinder, the air cylinder liner manufactured by the rotational molding process is more efficient and has better mechanical properties. The expanded range of material selection also enables rotational molding to adapt to a wider range of air cylinder production needs.

[0097] 2. The composite air cylinder and manufacturing method proposed by the present invention can achieve more uniform wall thickness throughout the product through the rotational molding process, which is essential to ensure the structural integrity and performance of the product. Since there is less material waste and high material utilization during the rotational molding process, production costs are reduced and the impact on the environment is reduced. This efficient material use and uniform wall thickness control make the rotational molding process an ideal choice when manufacturing large products or products with specific strength requirements.

[0098] 3. The composite air cylinder and manufacturing method proposed in the present invention significantly improve the strength and durability of the overall structure through the design of alternating winding circumferential winding layers and spiral winding layers, further optimize the winding layering method, achieve higher bursting pressure and residual bursting pressure after cycling, and ensure stability under high pressure and cyclic loads. The alternating winding method effectively disperses stress, reduces the risk of delamination damage, and enhances material utilization and structural balance performance. These improvements not only improve the load-bearing capacity of the air cylinder, but also ensure long-term reliability and safe operation, which is crucial to ensuring the safety and performance of rail vehicles.

[0099] 4. The composite air cylinder and manufacturing method proposed in the present invention achieves the optimization of material use by precisely controlling the winding angle and tension, as well as reasonable material distribution, which reduces weight and further reduces material waste, and is of great significance for improving the energy efficiency and dynamic performance of rail vehicles. Lightweight design also helps to reduce energy consumption and environmental impact, and meets the requirements of modern transportation for environmental protection and energy conservation. Through these technological innovations, the air cylinder not only improves its own performance, but also has a positive impact on the efficiency and economy of the entire rail vehicle system.

[0100] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0101] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0102] It should be noted that, in the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

Claims

1. A composite material air cylinder, characterized in that: The air cylinder comprises an inner container (110) and a winding layer (120). The liner comprises an liner body (111) and a plurality of metal tube seats (112); the winding layer (120) comprises a plurality of spiral winding layers (121) and a plurality of annular winding layers (122); The metal tube seat (112) and the inner liner body (111) are an integrally formed structure, the material of the winding layer (120) is carbon fiber, multiple layers of the spiral winding layer (121) and multiple layers of the annular winding layer are alternately wound on the outer surface of the inner liner (110), and the multiple layers of the spiral winding layer (121) and the multiple layers of the annular winding layer are bonded to the surface of the inner liner (110) by resin, and are cured and bonded to each other by the resin.

2. The air cylinder according to claim 1, characterized in that: The wall thickness of the inner container body (111) is 2 mm to 3 mm.

3. The air cylinder according to claim 1, characterized in that: The material of the inner liner body (111) includes high-density polyethylene roto-plastic or nylon roto-plastic.

4. The air cylinder according to claim 1, characterized in that: The metal pipe seat (112) comprises an intake pipe seat and an exhaust pipe seat.

5. The air cylinder according to claim 1, characterized in that: The resin includes epoxy resin, and the air cylinder also includes additives, which are one or more of halogen-free low-smoke flame retardants, anti-UV aging agents and toughening agents.

6. The air cylinder according to claim 1, characterized in that: The thickness of the winding layer (120) is 1.44 mm-1.56 mm.

7. The air cylinder according to claim 1, characterized in that: The angle formed between the multiple layers of the annular winding layer (122) and the axial direction of the inner container (110) is 88°-92°; The angle formed between the multiple spirally wound layers (121) and the axial direction of the inner container (110) is 19°-21° or 159°-161°.

8. The air cylinder according to claim 1, characterized in that: The winding layer (120) is composed of three windings, the winding group includes a circumferential winding group and a spiral winding group, the circumferential winding group includes multiple layers of the circumferential winding layer (122), and the spiral winding group includes multiple layers of the spiral winding layer (121); Starting from the surface of the inner liner (110), the winding layer (120) is composed of the annular winding group, the spiral winding group and the annular winding group from the inside to the outside.

9. The air cylinder according to claim 8, characterized in that: The plurality of circumferential winding layers (122) in the circumferential winding group are alternately placed in sequence at positions of 89±1° and 91±1° axially of the inner container (110), and the thickness of each circumferential winding layer is 0.12 mm-0.13 mm; The multiple spiral winding layers (121) in the spiral winding group are alternately placed in sequence at 20±1° and 160±1° axially of the inner liner (110), and the thickness of each spiral winding layer is 0.12mm-0.13mm.

10. The air cylinder according to claim 8, characterized in that: The ratio of the number of layers of the circumferential winding layer (122) to the number of layers of the spiral winding layer (121) in the winding group is 2:

1.

11. The air cylinder according to claim 10, characterized in that: The ratio of the number of layers of the circumferential winding layer (122) in the circumferential winding group to the number of layers of the spiral winding layer (121) in the spiral winding group is 1:

1.

12. A method for manufacturing the air cylinder as claimed in claim 1, characterized in that: include: S1: forming the metal tube seat (112) by machining, placing the metal tube seat (112) on a rotational molding mold of the inner liner body (111), and obtaining the inner liner (110) by a rotational molding process; S2: fixing the inner liner (110), and winding the multiple spiral winding layers (121) and the multiple hoop winding layers (122) soaked in the resin on the surface of the inner liner (110); S3: spraying protective paint on the surface of the cured air cylinder.

13. The method according to claim 12, characterized in that: The step S1 includes: The rotational molding mold of the liner body (111) is placed in a heating chamber for heating, and simultaneously undergoes orbital and rotational motions along the main and secondary axes that are perpendicular to each other in the heating chamber.

14. The method according to claim 13, characterized in that: The step S1 further includes: The temperature of the heating chamber is 250°C-260°C.

15. The method according to claim 12, characterized in that: The step S1 further includes: The inner surface of the rotational molding mold of the inner container body (111) is coated with a mold release agent.

16. The method according to claim 15, characterized in that: The step S1 further includes: The release agent includes one or more of oleic acid, paraffin and zinc stearate.

17. The method according to claim 12, characterized in that: The step S1 further includes: The rotationally molded inner liner (110) is demoulded, and the surface of the inner liner (110) is sandblasted.

18. The method according to claim 12, characterized in that: The step S2 further includes: The carbon fibers, which are the material of the winding layer (120), are impregnated with resin.

19. The method according to claim 12, characterized in that: The step S2 further includes: The inner container (110) is fixed on the rotating shaft of the winding machine.

20. The method according to claim 12, characterized in that: The step S2 includes: Winding a layer of the annular winding layer (122) at a position of 89±1° in the axial direction of the air cylinder, then winding a layer of the annular winding layer (122) at a position of 91±1° in the axial direction of the air cylinder, and repeating the above steps of winding a layer of the annular winding layer (122) until a set of annular winding groups is completed; Winding a layer of the spiral winding layer (121) at a position of 20±1° in the axial direction of the wind cylinder, then winding a layer of the spiral winding layer (121) at a position of 160±1° in the axial direction of the wind cylinder, and repeating the above step of winding a layer of the spiral winding layer (121) until a set of spiral winding groups is completed; After the spiral winding group is completed, a group of the hoop winding group is repeated again until the thickness of the winding layer (120) reaches 1.44mm-1.56mm.

21. The method according to claim 20, characterized in that: The step S2 includes: After each layer of the circumferential winding layer (122) or the spiral winding layer (121) is completed, when the next layer of the circumferential winding layer (122) or the spiral winding layer (121) is wound, the tension applied by the winding machine is reduced by 5N.

22. The method according to claim 12, characterized in that: The step S2 further includes: The inner container (110) wrapped with the wrapping layer (120) is placed in an oven for curing, and the curing temperature in the oven is 100° C.-120° C.

23. The method according to claim 22, characterized in that: The step S2 further includes: The surface of the air cylinder after solidification is polished.

24. The method according to claim 12, characterized in that: The step S3 includes: The protective paint is acrylic polyurethane.

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