Monolithic composite hopper truck bed and process for producing same

Abstract

The application provides a whole composite material hopper freight car compartment and a production process thereof. The whole composite material hopper freight car compartment comprises a chassis and a compartment body arranged on the chassis, the compartment body is integrated with an end wall plate, a side wall plate, a horizontal guide plate and a longitudinal guide plate, and the chassis is provided with a hinged door at a position opposite to the longitudinal ridge, and the longitudinal ridge is connected to form a discharge port. The production process of the whole composite material hopper freight car compartment comprises the steps of mold preparation, raw material blanking, layer processing, pouring and curing and mechanical processing. The whole composite material hopper freight car compartment and the production process thereof provided by the application solve the defects that the self-weight of the railway freight car compartment is too large, the existing carbon fiber composite material has poor weight reduction effect and the connection strength is weak.

Description

Technical Field

[0001] This invention relates to the field of railway carriages, specifically to an integral composite material funnel-shaped freight car and its manufacturing process. Background Technology

[0002] my country's railway transportation accounts for approximately 50% of the national economy's freight volume. Railway transportation is characterized by its large transport capacity, high speed, low cost, strong continuity, and environmental friendliness and energy efficiency. By the end of 2023, my country's railway freight car fleet had reached 1.007 million, ranking third in the world. To further enhance railway transport capacity, without upgrading existing railway lines, the overall weight of the wagons cannot be further increased; therefore, increasing cargo weight can only be achieved by reducing the wagon's tare weight.

[0003] Currently, existing railway freight cars are mainly made of metal materials, including steel and aluminum alloys. Due to the high density of metal materials, these cars are heavy and cannot significantly reduce their weight. Furthermore, metal cars suffer from severe corrosion, resulting in short service life and high maintenance workload. To reduce vehicle weight, vehicles using carbon fiber composite materials have recently been produced. This particular model is a hopper car, with the front and rear end panels and the two side panels made of carbon fiber composite sandwich panels. The four panels are connected to each other and to the frame using rivets. While the use of carbon fiber has reduced the car's weight to some extent, the extensive use of rivets and the hopper at the bottom of the car are still made of metal, resulting in a less than ideal weight reduction effect. Additionally, the elastic modulus of composite materials is lower than that of metal materials, leading to insufficient rigidity in this structure. This necessitates thickening the panels, further reducing the weight reduction effect. Moreover, the use of rivets to connect the panels results in weak connection strength. Summary of the Invention

[0004] To address the shortcomings of existing carbon fiber composite materials in reducing the weight of railway freight cars and their weak connection strength, this invention provides an integral composite funnel freight car and its manufacturing process that solves the above problems.

[0005] An integral composite material funnel-shaped freight car includes a base frame and a body placed on the base frame. The body includes an integral end wall panel, side wall panels, transverse guide plates, and longitudinal guide plates. The transverse guide plates form V-shaped transverse ridges with their tips pointing upwards, and the longitudinal guide plates form V-shaped longitudinal ridges with their tips pointing upwards. The two are connected to form a cross-shaped base. The end wall panels with outwardly sloping tops are provided at both ends of the longitudinal ridges, and the side wall panels are vertically provided at both ends of the transverse ridges. The side wall panels are connected to the end wall panels. The base frame supports the end wall panels and the side wall panels. The base frame has a hinged door opposite to the longitudinal ridge, which connects with the longitudinal ridge to form a discharge port. The end wall panels and the transverse ridges have retaining edges extending to both ends of the discharge port.

[0006] In a preferred embodiment of the integral composite funnel-shaped freight car body provided by the present invention, the end wall plate, the side wall plate, the transverse guide plate, and the longitudinal guide plate are all sandwich panels, including an outer skin, a core material, and an inner skin arranged in sequence; the outer skin and the inner skin are resin-based fiber-reinforced composite materials, and the core material is a foam material.

[0007] In a preferred embodiment of the integral composite material funnel-shaped freight car body provided by the present invention, the underframe includes side beams on both longitudinal sides and a central beam in the middle. The side beams support the side wall panels and are provided with the hatch doors. The central beam is connected to the longitudinal ridge. Support frames are provided at both ends of the top of the underframe to support the end wall panels.

[0008] In a preferred embodiment of the integral composite material funnel-shaped freight car body provided by the present invention, the bottoms of the transverse ridge, the end wall plate and the side wall plate are aligned, the longitudinal ridge is lower than the transverse ridge, and its lower end is connected to the flap door to form the unloading port.

[0009] In a preferred embodiment of the integral composite material funnel-shaped freight car body provided by the present invention, a plurality of reinforcing ribs are integrally provided within the side wall panels. A plurality of struts are vertically installed between the side wall panels.

[0010] A manufacturing process for an integral composite material funnel-shaped freight car body includes the following steps: Step 1, Mold Preparation: Clean the mold and apply release agent; Step 2, Raw material preparation: Prepare fiber fabric and foam core material according to the required dimensions; Step 3, Layering: Lay out the inner skin, foam core material, and outer skin in sequence; Step 4: Injection and curing: Seal the mold and test the pressure. After the pressure is qualified, mix the resin and perform vacuum injection and curing. After curing, cool down and demold. Step 5: Machining to ensure the product dimensions meet requirements.

[0011] In a preferred embodiment of the manufacturing process for the integral composite material funnel-shaped freight car body provided by the present invention, the specific steps include: Step 1, Mold preparation: Clean the mold and wash it thoroughly. Apply two or more layers of release agent to the surface of the mold, with an interval of 5 minutes or more between each layer. Step 2, Raw material preparation: Prepare fiber fabric and foam core material according to the required dimensions; Step 3, Layup Processing: Starting from the positions of the transverse and longitudinal guide plates, lay up the fiber fabric as the inner skin, lay it up longitudinally and cover the end wall plate area, then lay up the side wall plates and connect them to the end wall plates and guide plates; lay up the foam core material that supports the reinforcing ribs, and lay up the fiber fabric as the reinforcing ribs, then lay up the foam core material as the sandwich layer between the reinforcing ribs; then lay up the fiber fabric as the outer skin on the surface of the fiber fabric of the reinforcing ribs and the surface of the foam core material of the sandwich layer, the layup process is the same as that of the inner skin; finally, lay up the auxiliary materials. Step 4: Injection and Curing: Seal the mold around its perimeter, bag it, vacuum and test the pressure. If it passes the test, weigh and mix the resin, and perform vacuum injection; cure and cool down before demolding. Step 5: Machining to ensure the product dimensions meet requirements.

[0012] In step 2, two types of fiber fabrics with different weights are used; in step 3, in the fiber fabrics used as inner and outer skins, less than or equal half of the layup closest to the foam core material uses low weight fiber fabric, and the remaining layup uses high weight fiber fabric. The fiber fabric used as reinforcing ribs also uses high weight fiber fabric.

[0013] Compared with existing technologies, the integral composite material funnel-shaped freight car body and its manufacturing process provided by this invention have the following beneficial effects: 1. The vehicle body product provided by this invention uses resin-based fiber-reinforced composite material, achieving the effect of reducing the weight of the vehicle body. The excellent corrosion resistance of the composite material avoids the vehicle maintenance costs caused by corrosion of metal materials, saving costs and extending service life.

[0014] 2. The carriage product provided by the present invention adopts a sandwich structure of sheet material, and the core layer is integrally molded with lightweight foam material, which overcomes the disadvantage that the elastic modulus of composite materials is less than that of metal materials. The product rigidity is improved by increasing the thickness without significantly increasing the product weight.

[0015] 3. The vehicle body product provided by this invention features an integrally molded mid-section wall panel, side wall panels, transverse guide panels, and longitudinal guide panels, forming a continuous internal fiber assembly. This eliminates the need for numerous rivets connecting the panels, further reducing weight. The integral molding significantly enhances the strength and rigidity of the vehicle body, effectively preventing vehicle deformation and improving product safety.

[0016] 4. In the carriage product provided by the present invention, the horizontal guide plate and the vertical guide plate form a V-shaped horizontal ridge and a vertical ridge, forming a cross-shaped base, which improves the deformation resistance of the carriage panel.

[0017] 5. The carriage manufacturing process provided by this invention adopts an inside-out processing technology, which can achieve the effect of integral molding of the carriage product, eliminate the need for a large number of rivets required to connect the plates, and achieve the purpose of reducing weight and enhancing the strength and rigidity of the carriage.

[0018] 6. In the carriage manufacturing process provided by the present invention, a scheme of mixed lay-up of two types of fiber fabrics with different weights is adopted. The outer layer of fiber fabric has a higher elastic modulus, and the inner layer of fiber fabric can better withstand low-speed impacts, thereby enhancing the wall panel's resistance to external impacts.

[0019] 7. In the carriage manufacturing process provided by the present invention, continuous fiber cloth is used for layering between the longitudinal guide plate and the end wall plate, between the end wall plate and the side wall plate, and between the side wall plate and the transverse guide plate, so that the carriage product becomes an integrated structure with continuous internal fibers. Attached Figure Description

[0020] Figure 1 This is a perspective view of the integral composite material funnel-shaped freight car body in Example 1; Figure 2 yes Figure 1 3D view of the mid-frame; Figure 3 yes Figure 1 A three-dimensional view of the compartment; Figure 4 yes Figure 1 A three-dimensional sectional view of the compartment body; Figure 5 This is a perspective view of the integral composite material funnel-shaped freight car body in Example 2.

[0021] The following components are labeled in the diagram: base frame 1, side beam 11, end beam 12, middle beam 13, trapdoor 14, support frame 15, box body 2, end wall panel 21, side wall panel 22, transverse guide plate 23, longitudinal guide plate 24, edge guard 25, reinforcing rib 26, strut 3. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0023] Example 1: Please also refer to Figures 1 to 4 These are, respectively, a perspective view of the integral composite material funnel freight car in this embodiment, a perspective view of the underframe and body of the integral composite material funnel freight car, and a perspective view of the body after being cut laterally.

[0024] The integral composite material funnel truck body includes a chassis 1 and a body 2 mounted on the chassis 1. The structure of the chassis 1 is similar to that of existing funnel truck chassis, including side beams 11 and end beams 12 spliced ​​into a frame shape, and a central beam 13 arranged parallel to the side beams 11. On the outer sides of the two side beams 11, two trapdoors 14 are symmetrically arranged along the length direction. At both ends of the top of the frame, two outwardly sloping support frames 15 are also symmetrically arranged.

[0025] The body 2 is made of carbon fiber in one piece. For ease of description, it is divided into end wall plate 21, side wall plate 22, transverse guide plate 23 and longitudinal guide plate 24.

[0026] Two horizontal guide plates 23 form an upward-pointing V-shaped horizontal ridge, and four vertical guide plates 24 form two upward-pointing V-shaped vertical ridges. The two vertical ridges are vertically positioned on both sides of the horizontal ridges, forming a cross-shaped base. The top of the vertical ridges is lower than the top of the horizontal ridges, and the bottom of the vertical ridges is lower than the bottom of the horizontal ridges. At four positions between the two horizontal guide plates 23 and the two vertical guide plates 24, triangular retaining edges 25 are provided vertically, thereby connecting and closing the ends of the vertical guide plates 24.

[0027] Each of the two outer ends of the longitudinal ridge is provided with an end wall plate 21 with an outwardly sloping top. The bottom of the end wall plate 21 is at the same height as the bottom of the transverse ridge, and similarly, triangular baffles 25 are provided vertically at four positions between the end wall plate 21 and the two longitudinal guide plates 24, thereby connecting and closing the ends of the longitudinal guide plates 24. Thus, the four longitudinal guide plates 24 and the baffles 25 at their ends form four externally open discharge ports, the outside of which are closed by a trapdoor 14.

[0028] Resin sidewall panels 22 are provided at both ends of the transverse ridge. The bottom of the sidewall panel 22 is at the same height as the bottom of the transverse ridge, and after rising a certain height (the thickness of the side beam 11), it thickens outward, with reinforcing ribs 26 arranged in the thickened surface. The protruding part of the sidewall panel 22 also serves to provide a limit, allowing it to rest on the side beam 11. The two ends of the sidewall panel 22 are connected to the end wall panel 21 to form a closed compartment. The top ring of the end wall panel 21 and the sidewall panel 22 is thickened outward to increase strength and also to provide a limit, allowing it to rest on the support frame 15.

[0029] Furthermore, due to the relatively long length of the side wall panel 22, and the fact that it is only fixed at the ends, additional struts 3, secured by rivets, are added between the two side wall panels 22 to increase strength. The struts 3 provide tension between the two opposing side wall panels 22, reducing deformation of the side wall panels 22.

[0030] The central beam 13 is used to support and position the box body 2. Since the bearing position corresponds to the longitudinal ridge and the contact surface is V-shaped, a support plate is added to abut against the bottom of the longitudinal ridge.

[0031] The support frame 15 abuts against the outer side of the end wall plate 21 and the bottom of the reinforcing ring on its top, providing longitudinal restraint and vertical load-bearing functions.

[0032] When the trapdoor 14 closes inward, it seals the discharge port; when it opens outward, it opens the discharge port, thus realizing the loading and unloading function. The corresponding control mechanism is existing technology and is omitted here.

[0033] The end wall panel 21, side wall panel 22, transverse guide plate 23, and longitudinal guide plate 24 all adopt a sandwich structure. Specifically, it includes an inner skin, a core material, and an outer skin arranged in sequence.

[0034] Both the inner and outer skins are made of carbon fiber fabric, with the core material being lightweight PET foam. The thickened areas of the side wall panels 22 are equipped with reinforcing ribs 26, which are also made of lightweight PET foam and wrapped with carbon fiber fabric. Details are as follows: A manufacturing process for an integral composite material funnel-shaped freight car body: Step 1, Mold Preparation: Clean the mold thoroughly of any residual resin residue. Clean the mold with a lint-free cloth soaked in industrial alcohol, ensuring the surface is clean and free of oil stains, dust, and other impurities. After the alcohol has dried completely, apply an appropriate amount of mold release agent to the mold surface with a lint-free cloth, ensuring even application. Wait 5 minutes after the first application before applying the second.

[0035] Step 2, Raw Material Preparation: Prepare fiber fabric and PET foam core material according to the required dimensions. This includes half of the 600g / ㎡ carbon fiber fabric and half of the 800g / ㎡ carbon fiber fabric.

[0036] Step 3, Layering: Lay out the inner skin, foam core material, and outer skin in sequence. That is, using an internal mold structure, lay out the constituent materials of the body layer by layer from the inside to the outside.

[0037] Specifically, starting from the positions of the horizontal guide plate 23 and the vertical guide plate 24 on the mold, a fiber fabric is laid up as the inner skin. The fabric is then laid up longitudinally, covering the upper end wall plate 21 of the mold, followed by the side wall plate 22, and connected to the end wall plate 21 and the horizontal guide plate 23. During the layup process, a scheme using 800g / m² carbon fiber fabric for the first half of the thickness and 600g / m² carbon fiber fabric for the second half is adopted. Preferably, 10 layers are laid up, each with a thickness of 0.2mm.

[0038] Then, the foam core material supporting the reinforcing ribs is laid. In this embodiment, the side wall panel 22 has a structure with a concave inner wall and a flat outer wall. Therefore, protrusions are pre-fabricated on the mold, and the inner skin forms grooves between the protrusions to accommodate the foam core material supporting the reinforcing ribs 26. Next, the foam core material serving as the reinforcing ribs 26 is laid on the inner skin, followed by a layer of fiber fabric serving as the reinforcing ribs 26. Here, 800g / ㎡ carbon fiber fabric is used.

[0039] Where there are irregular corners or joints where the fabric cannot be bent to cover the edges, or where differences in length on both sides cause wrinkles, the wrinkled areas should be cut open and the layers laid out using an overlapping method. The overlap width should be 15-50mm, and the overlap positions should be staggered layer by layer, with each layer staggered by at least 50mm.

[0040] Then, foam core material is laid between the reinforcing ribs 26 as a sandwich layer. After the sandwich layer is laid, it is at the same height as the reinforcing ribs 26, and the outer wall of the compartment 2 is flat. At the locations where the support rods 3 are installed, the foam core material is replaced with pressure-resistant embedded parts, or solid carbon fiber fabric is used directly to increase the installation strength at the connection points. At the locations containing the reinforcing ribs 26, the thickness from the inner wall of the inner skin to the outer wall of the outer skin is 60mm, and at the locations without the reinforcing ribs 26, the thickness is 20mm.

[0041] The fiber fabric used as the outer skin is then laid down. A scheme using 600g / ㎡ carbon fiber fabric for the first half of the thickness and 800g / ㎡ carbon fiber fabric for the second half is adopted.

[0042] When laying the inner and outer skin layers, starting from the longitudinal guide plate 24 on the mold, the same piece of fiber cloth is continuously laid to the end wall plate 21; starting from the end wall plate 21 on the mold, the same piece of fiber cloth is continuously laid to the side wall plate 22; starting from the side wall plate 22 on the mold, the same piece of fiber cloth is continuously laid to the transverse guide plate 23.

[0043] Finally, lay the auxiliary materials, including the release cloth, release film, flow guide net, and pipeline accessories.

[0044] Step 4: Injection and Curing: Apply sealing strips around the mold, seal with a vacuum bag, and then vacuum-pressurize. After 30 seconds, a pressure drop of ≤0.1 kPa is acceptable. Then, weigh and mix the resin according to the product size and thickness, and perform vacuum injection.

[0045] After the infusion is completed, the product enters the curing process. The post-curing conditions are: at room temperature (25℃), heat up for half an hour to reach 75±5℃, then keep warm for 1.5 hours, then heat up for another half hour to reach 125±5℃, keep warm for 2.5 hours to finish, and after curing, cool down to below 60℃ to demold.

[0046] Step 5: Machining, ensuring that the product dimensions meet the requirements of the product drawings.

[0047] Example 2: Please refer to Figure 5 This is a perspective view of the integral composite material funnel-shaped freight car body in this embodiment.

[0048] In this embodiment, the side wall panel 22 has a structure with both inner and outer walls being flat. Since the mold is flat on the panel surface, it is necessary to lay the foam core material for the load-bearing reinforcing ribs 26 according to the product structure design. Other aspects are consistent with Embodiment 1.

[0049] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. An integral composite material funnel-shaped freight car body, comprising a base frame and a body placed on the base frame, characterized in that: The body includes an integral end wall panel, side wall panel, transverse guide plate, and longitudinal guide plate. The transverse guide plate forms an upward-pointing V-shaped transverse ridge, and the longitudinal guide plate forms an upward-pointing V-shaped longitudinal ridge. The two are connected to form a cross-shaped base. The two ends of the longitudinal ridge are provided with the end wall panel with an outwardly sloping top. The two ends of the transverse ridge are provided with the side wall panel vertically. The side wall panel is connected to the end wall panel. The base frame supports the end wall panel and the side wall panel. The base frame is provided with a hinged door opposite to the longitudinal ridge, which connects with the longitudinal ridge to form a discharge port. The end wall panel and the transverse ridge are provided with retaining edges extending to both ends of the discharge port.

2. The integral composite material funnel-shaped freight car body according to claim 1, characterized in that: The end wall panel, the side wall panel, the transverse guide plate, and the longitudinal guide plate are all sandwich panels, comprising an outer skin, a core material, and an inner skin arranged sequentially; the outer skin and the inner skin are resin-based fiber-reinforced composite materials, and the core material is foam material.

3. The integral composite material funnel-shaped freight car body according to claim 2, characterized in that: The base frame includes side beams on both sides and a central beam in the middle. The side beams support the side wall panels and are equipped with the trapdoors. The central beam is connected to the longitudinal ridge.

4. The integral composite material funnel-shaped freight car body according to claim 3, characterized in that: The base frame is equipped with support frames at both ends of the top to support the end wall panels.

5. The integral composite material funnel-shaped freight car body according to any one of claims 2 to 4, characterized in that: The bottoms of the transverse ridge, the end wall panel, and the side wall panel are aligned, the longitudinal ridge is lower than the transverse ridge, and its lower end is connected to the flap door to form the unloading port.

6. The integral composite material funnel-shaped freight car body according to any one of claims 2 to 4, characterized in that: The side wall panel is integrally provided with multiple reinforcing ribs.

7. The integral composite material funnel-shaped freight car body according to any one of claims 2 to 4, characterized in that: Multiple struts are installed vertically between the side wall panels.

8. A manufacturing process for an integral composite material funnel-shaped freight car body as described in any one of claims 2 to 7, characterized in that, Includes the following steps: Step 1, Mold Preparation: Clean the mold and apply release agent; Step 2, Raw material preparation: Prepare fiber fabric and foam core material according to the required dimensions; Step 3, Layering: Lay out the inner skin, foam core material, and outer skin in sequence; Step 4: Injection and curing: Seal the mold and test the pressure. After the pressure is qualified, mix the resin and perform vacuum injection and curing. After curing, cool down and demold. Step 5: Machining to ensure the product dimensions meet requirements.

9. The manufacturing process of the integral composite material funnel-shaped freight car body according to claim 8, characterized in that, Specifically, the following steps are included: Step 1, Mold preparation: Clean the mold and wash it thoroughly. Apply two or more layers of release agent to the surface of the mold, with an interval of 5 minutes or more between each layer. Step 2, Raw material preparation: Prepare fiber fabric and foam core material according to the required dimensions; Step 3, Layup Processing: Starting from the positions of the transverse and longitudinal guide plates, lay up the fiber fabric as the inner skin, lay up longitudinally and cover the end wall plate area, then lay up the side wall plates and connect them with the end wall plates and guide plates; lay up the foam core material that supports the reinforcing ribs, and lay up the fiber fabric as the reinforcing ribs, and then lay up the foam core material as the sandwich layer between the reinforcing ribs. Then, on the surface of the reinforcing fiber fabric and the surface of the foam core material of the sandwich layer, a fiber fabric as the outer skin is laid up, and the laying process is the same as that of the inner skin. Finally, lay the auxiliary materials; Step 4: Injection and Curing: Seal the mold around its perimeter, bag it, vacuum and test the pressure. If it passes the test, weigh and mix the resin, and perform vacuum injection; cure and cool down before demolding. Step 5: Machining to ensure the product dimensions meet requirements.

10. The manufacturing process of the integral composite material funnel-shaped freight car body according to claim 8, characterized in that; In step 2, two types of fiber fabrics with different weights are used; in step 3, in the fiber fabrics used as inner and outer skins, less than or equal half of the layup closest to the foam core material uses low weight fiber fabric, and the remaining layup uses high weight fiber fabric. The fiber fabric used as reinforcing ribs also uses high weight fiber fabric.

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