Forming method of variable-section aluminum honeycomb panel cab skin

Abstract

The invention relates to a forming method of a variable-section aluminum honeycomb panel cab skin, which belongs to the technical field of railway vehicles, and comprises the following steps: S100, welding a panel and an aluminum honeycomb core material into a plate, and selecting plates with different section shapes and sizes at different positions of the cab skin; s200, carrying out primary profiling on the plate by adopting a first mold, wherein the first mold is a wooden mold; s300, carrying out secondary profiling on the plate subjected to primary profiling by adopting a second mold, wherein the second mold is a steel mold; s400, the plate obtained after secondary profiling is subjected to shape modification through a first mold, and a skin part is obtained; s500, the skin parts are installed and welded, and the variable-section aluminum honeycomb panel cab skin is obtained.The variable-section aluminum honeycomb panel cab skin can solve the technical problems that in the prior art, the welding amount is large, repairing is not easy, modularization and light weight are difficult to achieve, and cost is high.

Description

Technical Field

[0001] The invention belongs to the technical field of rail vehicles, and in particular relates to a method for forming a variable-section aluminum honeycomb panel driver's cab skin. Background Art

[0002] Traditional driver's cabs are generally divided into two structures. One is an aluminum alloy truss frame plus an aluminum single plate skin welding structure, commonly known as a plate beam structure. Due to the low rigidity of the aluminum plate itself, more rib plate structures need to be arranged to increase rigidity and support capacity, resulting in problems such as heavy weight, large welding volume, large deformation, and difficult to control deformation, and poor sound insulation effect; the other is a fiberglass or carbon fiber composite material plus aluminum alloy frame structure. Many connection seats and connection blocks need to be pre-buried inside the skin mask. The process is relatively complicated and difficult to repair. In addition, a large amount of sealant is used for bonding and sealing. The product has poor sealing and the material is environmentally friendly. Therefore, the existing two structures of driver's cabs are difficult to meet actual application needs, and both are difficult to achieve modularization and lightweight, and the cost remains high. Summary of the invention

[0003] In view of the various deficiencies of the prior art, a forming method for a variable-section aluminum honeycomb panel cab skin is proposed to solve the technical problems of the prior art, such as large welding volume, difficulty in repair, difficulty in achieving modularization and lightweight, and high cost.

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

[0005] A method for forming a variable-section aluminum honeycomb panel cab skin comprises the following steps:

[0006] S100, weld the panel and the aluminum honeycomb core material into a plate, and use plates with different cross-sectional shapes and sizes at different positions of the cab skin;

[0007] S200, performing initial profiling on the plate using a first mold, wherein the first mold is a wooden mold;

[0008] S300, performing secondary pressing on the plate after the initial pressing using a second mold, wherein the second mold is a steel mold;

[0009] S400, using the first mold to reshape the plate after the secondary pressing to obtain a skin part;

[0010] S500, assembling and welding the skin parts to obtain a variable-section aluminum honeycomb panel cab skin.

[0011] The technical solution is further configured that, in the step S100, different positions of the cab skin have different performance requirements, and the performance includes sound insulation, rigidity, impact resistance, lightness and bending strength, and the performance and the plate size meet the following conditions:

[0012] The thickness of the aluminum honeycomb core material, the thickness of the panel, and the side length of the honeycomb holes of the aluminum honeycomb core material decrease, and the sound insulation tends to increase;

[0013] As the thickness of the aluminum honeycomb core material, the thickness of the panel, and the side length of the honeycomb holes of the aluminum honeycomb core material increase, the impact resistance tends to increase;

[0014] The smaller the surface density, the higher the degree of lightweight;

[0015] As the ratio of the wall thickness of the aluminum honeycomb core material to the side length of the honeycomb cells increases, the bending strength and stiffness both tend to increase.

[0016] The technical solution is further configured such that, in step S100, the cross-sectional shape of the plate includes a sandwich type, a corrugated type, a cellular type, a cone type, a curved surface type, a dissimilar metal type, and a locally reinforced type.

[0017] The technical solution is further configured that, in the step S200 and the step S400, the pressing pressure of the first mold is 80-160t, the pressing speed is 50-80mm / s, the pressure release time and the pressure holding time are 25-50s, and the standing time is 4-10min.

[0018] The technical solution is further configured that, during the initial pressing process, when When the pressing pressure is 80-95t, the pressing speed is 50-70mm / s, the pressure relief time and pressure holding time are 35-50s, and the static time is 5-10min; when When the forming pressure is 90-160t, the pressing speed is 60-80mm / s, the pressure relief time and the pressure holding time are 25-30s, and the standing time is 7-10min; wherein, R represents the inner arc radius of the skin part, and T represents the thickness of the skin part.

[0019] The technical solution is further configured that, during the shaping process, when When the pressing pressure is 80-90t, the pressing speed is 50-60mm / s, the pressure relief time and pressure holding time are 25-50s, and the static time is 7-10min; The pressing pressure is 90-120t, the pressing speed is 60-70mm / s, the pressure relief time and the pressure holding time are 25-30s, and the standing time is 7-10min; wherein R represents the inner arc radius of the skin part, and T represents the thickness of the skin part.

[0020] The technical solution is further configured as follows: in step S300, the pressing pressure of the second mold is 70-120t, the pressing speed is 40-50mm / s, the pressure release time and the pressure holding time are 25-30s, and the standing time is 2-5min.

[0021] The technical solution is further configured that, during the secondary pressing process, when When the pressing pressure is 70-80t, the pressing speed is 40-50mm / s, the pressure relief time and pressure holding time are 25-30s, and the static time is 2-5min; When the pressing pressure is 80-120t, the pressing speed is 40-50mm / s, the pressure relief time and the pressure holding time are 25-30s, and the standing time is 2-5min; wherein R represents the inner arc radius of the skin part, and T represents the thickness of the skin part.

[0022] The technical solution is further configured as follows: in the step S500, adjacent skin parts are spliced ​​by profiles, grooves are provided at the splicing locations of the skin parts, and ends of the profiles are embedded in the grooves and welded.

[0023] The beneficial effects of the present invention are:

[0024] Lightweight aluminum honeycomb panel skin is used as the driver's cab skin, replacing traditional non-metallic materials and plate-beam structures such as fiberglass or carbon fiber, which well realizes lightweight, modularization, and repairability, with small welding volume and low cost; the cross-sectional shape and size of the panel can be selected according to the design requirements of different locations, and the sound insulation, rigidity, impact resistance and bending strength can be changed by changing the spatial structure of the aluminum honeycomb core material; in addition, the skin parts are made by step-by-step molding using wooden molds and steel molds to control the amount of rebound and improve the molding effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a flow chart of a method for forming a driver's cab skin of a variable-section aluminum honeycomb panel in an embodiment of the present invention;

[0026] Figure 2 is a schematic diagram of a sandwich-shaped cross-section of a plate in an embodiment of the present invention;

[0027] Figure 3 is a schematic diagram of a cross-sectional shape of a plate material in an embodiment of the present invention being a corrugated type;

[0028] Figure 4 is a schematic diagram of a plate having a cellular cross-sectional shape in an embodiment of the present invention;

[0029] Figure 5 is a schematic diagram of a plate having a conical cross-sectional shape in an embodiment of the present invention;

[0030] Figure 6 is a schematic diagram of a plate having a curved cross-sectional shape in an embodiment of the present invention;

[0031] Figure 7It is a schematic diagram of a cross-sectional shape of a plate in an embodiment of the present invention being a heterogeneous metal type;

[0032] Figure 8 It is a schematic diagram of a cross-sectional shape of a plate in an embodiment of the present invention that is a local reinforcement type;

[0033] In the attached figure: 1. upper panel; 2. aluminum honeycomb core material; 3. lower panel; 4. solder layer; 5. transition layer; 6. reinforced aluminum honeycomb panel; 7. cell structure. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings of the present invention. Based on the embodiments in this application, other similar embodiments obtained by ordinary technicians in this field without making creative work should all fall within the scope of protection of this application. In addition, the directional words mentioned in the following embodiments, such as "up", "down", "left", "right", etc., are only reference to the directions of the accompanying drawings. Therefore, the directional words used are used to illustrate rather than limit the invention.

[0035] According to an embodiment of the present invention, a method for forming a driver's cab skin of a variable-section aluminum honeycomb panel is provided. Figure 1 , including the following steps:

[0036] S100, weld the panel and the aluminum honeycomb core material into a plate, and use plates with different cross-sectional shapes and sizes at different positions of the cab skin;

[0037] S200, performing initial profiling on the plate using a first mold, wherein the first mold is a wooden mold;

[0038] S300, performing secondary pressing on the plate after the initial pressing using a second mold, wherein the second mold is a steel mold;

[0039] S400, using the first mold to reshape the plate after the secondary pressing to obtain a skin part;

[0040] S500, assembling and welding the skin parts to obtain a variable-section aluminum honeycomb panel cab skin.

[0041] It should be noted that the use of lightweight aluminum honeycomb panels as the cab skin replaces traditional non-metallic materials and plate beam structures such as fiberglass or carbon fiber, which is lightweight, modular, and repairable, with small welding volume and low cost. The cross-sectional shape and size of the panels can be selected according to the design requirements of different locations. By changing the spatial structure of the aluminum honeycomb core material, its sound insulation, rigidity, impact resistance, and bending strength can be changed. In addition, the skin parts are molded in steps through wooden molds and steel molds to control the rebound amount and improve the molding effect.

[0042] In the forming method of the variable cross-section aluminum honeycomb panel cab skin of the present embodiment, in the step S100, the performance requirements of different positions of the cab skin are different, and the performance includes sound insulation, rigidity, impact resistance, lightness and bending strength, and the performance and the plate size meet the following conditions:

[0043] The thickness of the aluminum honeycomb core material, the thickness of the panel, and the side length of the honeycomb holes of the aluminum honeycomb core material decrease, and the sound insulation tends to increase;

[0044] As the thickness of the aluminum honeycomb core material, the thickness of the panel, and the side length of the honeycomb holes of the aluminum honeycomb core material increase, the impact resistance tends to increase;

[0045] The smaller the surface density, the higher the degree of lightweight;

[0046] As the ratio of the wall thickness of the aluminum honeycomb core material to the side length of the honeycomb cells increases, the bending strength and stiffness both tend to increase.

[0047] In the forming method of the variable cross-section aluminum honeycomb panel cab skin of this embodiment, please refer to Figure 1 In the step S100, the cross-sectional shape of the plate includes a sandwich type, a corrugated type, a cellular type, a cone type, a curved surface type, a dissimilar metal type, and a locally reinforced type.

[0048] For details, please refer to the sandwich type Figure 2 There are brazing material layers between the aluminum honeycomb core material 2 and the upper panel 1, and between the aluminum honeycomb core material 2 and the lower panel 3. The cross-sectional shape of the aluminum honeycomb core material 2 is a conventional geometric shape. This structure is mostly used for urban rail vehicles with higher speeds. It has outstanding properties such as specific stiffness, specific strength, sound insulation, electromagnetic shielding, and bending resistance, which meets the strength requirements while achieving lightweight requirements.

[0049] For details, please refer to Figure 3 The aluminum honeycomb core material 2 has a corrugated structure; in addition to being used for the driver's cab skin, it can also be used for the driver's cab floor, with low strength, low production cost and light weight.

[0050] For more information, please refer to Figure 4 The aluminum honeycomb core material 2 is composed of a plurality of cell structures 7 arranged in a matrix; the structure can be used for the skin of a subway or urban rail driver's cab with a low speed, and can also be used for decorative floors or roof panels, eliminating the need for core material molding and can be formed by stamping, which has low cost and high production efficiency.

[0051] For details, please refer to Figure 5 The thickness of the aluminum honeycomb core material 2 increases or decreases. This cross-sectional shape is particularly suitable for flight resistance design requirements. For curved surface type, please refer to Figure 6The thickness of the aluminum honeycomb core material 2 changes in a curve, and this cross-sectional shape is particularly suitable for flight resistance design requirements; these two structures are mostly used in window frames and lamp frames of the driver's cab skin, and can also be used in external shells in the aerospace field, taking into account flight resistance, installation space and overall lightweight requirements.

[0052] For specific information, please refer to Figure 7 There are transition layers 5 between the upper panel 1 and the brazing material layer 4, and between the lower panel 3 and the brazing material layer 4. Among them, the upper panel 1 is made of carbon steel panel, the lower panel 3 is made of aluminum alloy panel, and the transition layer 5 is made of 1 series or 3 series aluminum-based material; when the carbon steel panel is impacted or subjected to greater pressure, it is not easy to deform and small pits can be avoided. It is usually used in places where panel stiffness and hardness are required, such as the mounting seat of driver's cab components.

[0053] For details, please refer to the local reinforcement type Figure 8 The end of the aluminum honeycomb core material 2 is welded with a reinforcing aluminum honeycomb panel 6. Similarly, the reinforcing aluminum honeycomb panel 6 adopts a conventional sandwich type; local reinforcement is performed at the joint connection, which not only increases the thickness of the parent material, meets the strength requirements but also achieves lightweight. It is usually used at the connection between the cab skin and the frame.

[0054] In the forming method of the variable cross-section aluminum honeycomb panel cab skin of the present embodiment, in the step S200 and the step S400, the pressing pressure of the first mold is 80-160t, the pressing speed is 50-80mm / s, the pressure release time and the pressure holding time are 25-50s, and the standing time is 4-10min.

[0055] It should be noted that when fixing the first mold on the four-axis press, attention should be paid to the installation position of the upper mold and the lower mold. The positioning holes should be aligned with the positioning holes on the first mold and fixed firmly and reliably. Adjust the press pressure to 80-160t, press down slowly at a speed of 50-80mm / s until the upper and lower molds fit the sheet, let it stand for 4-10min, and the pressure release time and pressure holding time are 25-50s.

[0056] Specifically, during the initial pressing process, When the pressing pressure is 80-95t, the pressing speed is 50-70mm / s, the pressure relief time and pressure holding time are 35-50s, and the static time is 5-10min; when When the forming pressure is 90-160t, the pressing speed is 60-80mm / s, the pressure relief time and the pressure holding time are 25-30s, and the standing time is 7-10min; wherein, R represents the inner arc radius of the skin part, and T represents the thickness of the skin part.

[0057] Specifically, during the modification process, When the pressing pressure is 80-90t, the pressing speed is 50-60mm / s, the pressure relief time and pressure holding time are 25-50s, and the static time is 7-10min; The pressing pressure is 90-120t, the pressing speed is 60-70mm / s, the pressure relief time and the pressure holding time are 25-30s, and the standing time is 7-10min; wherein R represents the inner arc radius of the skin part, and T represents the thickness of the skin part.

[0058] It should be noted that wooden molds are used for initial profiling and repairing. When the pressure is less than 80t, the profiling effect is not good, the rebound is large, and it is difficult to form. When the pressure value is greater than 160t, the plate is easily crushed. When the pressing speed is less than 50mm / s, the production efficiency is low, and when the pressing speed is greater than 80mm / s, the plate is easily crushed locally. If the standing time is less than 4min, it is easy to rebound. If the standing time is greater than 10min, the effect is not obvious and the efficiency is low. If the pressure relief and holding time is less than 25s, it is easy to rebound. If the pressure relief and holding time is 50s, the production rhythm slows down.

[0059] In the forming method of the variable cross-section aluminum honeycomb panel cab skin of this embodiment, please refer to Figure 1 In the step S300, the pressing pressure of the second mold is 70-120t, the pressing speed is 40-50mm / s, the pressure release time and the pressure holding time are 25-30s, and the standing time is 2-5min.

[0060] It should be noted that when fixing the second mold on the four-axis press, attention should be paid to the installation position of the upper and lower molds. The positioning holes should be aligned with the positioning holes on the first mold and fixed firmly and reliably. Adjust the press pressure to 70-120t, press down slowly at a speed of 40-50mm / s until the upper and lower molds fit the sheet, let it stand for 2-5min, and the pressure release time and pressure holding time are 25-30s.

[0061] Specifically, during the secondary pressing process, When the pressing pressure is 70-80t, the pressing speed is 40-50mm / s, the pressure relief time and pressure holding time are 25-30s, and the static time is 2-5min; When the pressing pressure is 80-120t, the pressing speed is 40-50mm / s, the pressure relief time and the pressure holding time are 25-30s, and the standing time is 2-5min; wherein R represents the inner arc radius of the skin part, and T represents the thickness of the skin part.

[0062] It should be noted that when the pressing pressure is greater than 120t, the plate is easily crushed and wrinkles appear on the inside of the plate; when the pressing pressure is less than 70t, the shaping effect is not good, and the rebound and contour are both poor; when the pressing speed is less than 40mm / s, the production efficiency is low and the shaping effect is poor. When the pressing speed is greater than 50mm / s, the plate is easily crushed locally. Compared with wooden molds, steel molds are more sensitive to pressing pressure and pressing speed. When adjusting, the value change should be as small as possible. Preferably, the pressing pressure change rate is 3t / s and the pressing speed change rate is 2mm / s.

[0063] The inventor discovered in long-term practice that When the skin part is pressed, the inner arc radius is small. As the inner side of the arc is subjected to compressive stress, and as the pressure value and the downward pressure speed increase, the instantaneous compressive stress increases, which can easily cause the inner structure of the skin part to become unstable and crushed, and lose its unique function. When using wooden molds for pressing, as the pressure holding time and pressure release time increase, the rebound amount becomes smaller, which is conducive to controlling the rebound amount; When the pressure is increased, the inner arc radius of the skin part is relatively large, and the compressive stress on the inner side of the arc is not as concentrated. As the pressure value and the downward pressure speed increase, the compressive stress becomes larger, but the inner structure of the skin part will not become unstable and collapse. In order to improve efficiency, the parameters can be appropriately adjusted.

[0064] In the forming method of the variable cross-section aluminum honeycomb panel cab skin of this embodiment, please refer to Figure 1 In the step S500, adjacent skin parts are spliced ​​by profiles, grooves are provided at the joints of the skin parts, and the ends of the profiles are embedded in the grooves and welded.

[0065] The present invention adopts a lightweight aluminum honeycomb panel with a designable cross section as the driver's cab skin, replacing traditional non-metallic materials such as fiberglass or carbon fiber. The main advantages are as follows:

[0066] 1. Lightweight: The skin is made of a new type of microstructured pure metal composite hollow structural material, with high rigidity and strength, good sound insulation, light weight, good impact resistance, environmental protection and recyclability. On the basis of meeting the design load, the weight is greatly reduced to achieve lightweight design. The weight of the conventional fiberglass or carbon fiber composite skin driver's cab is about 540kg, and the weight of the lightweight aluminum honeycomb panel driver's cab skin with designable cross-section is about 450kg, and the weight reduction can reach about 20%.

[0067] 2. The cross-section can be designed; the skin can be flexibly designed according to the load-bearing requirements, service environment and interface size requirements. The cross-sectional shape and size can be designed to meet various stiffness and strength, sound insulation and impact requirements, achieve precise design and save material costs.

[0068] 3. Modularization: The pressing technology combining steel molds and wooden molds helps to achieve modular production. The driver's cab frame and skin can be made as an independent module. Finally, the modular skin and frame are welded together to achieve modular production, shorten the production cycle, simplify the manufacturing process, and save labor costs.

[0069] 4. Good sound insulation and temperature resistance: The sound insulation of the lightweight skin with designed cross-section is ≥26dB. Through changes in specifications and structure, the sound insulation of the skin can reach 31dB. The aluminum honeycomb panel is formed at a high temperature of 500-600℃ and has strong high temperature resistance. The interior of the plate beam skin adopts damping slurry and other sound insulation treatments, and the sound insulation is ≥20dB. FRP is not resistant to high temperatures, and its performance will be significantly reduced at ≥50℃.

[0070] 5. Repairable by welding: When the fiberglass mask skin is damaged by impact, the mask cannot be used and can only be replaced, which is time-consuming, labor-intensive and costly. The skin of the present invention can be repaired by welding at the collision site, which is convenient and quick, and the strength remains the same as the original one.

[0071] 6. Small amount of welding: Compared with the plate-beam structure skin, the welding amount is reduced and the spatial position welding demand is reduced, which solves the problems of large welding amount, high welding difficulty, large deformation and difficult shaping in traditional plate-beam structure.

[0072] The present invention has been described in detail above. The above description is only a preferred embodiment of the present invention and should not limit the scope of implementation of the present invention. That is, all equivalent changes and modifications made within the scope of this application should still fall within the scope of the present invention.

Claims

1. A method for forming a variable cross-section aluminum honeycomb panel cab skin, characterized in that: The following steps are involved: S100, weld the panel and the aluminum honeycomb core material into a plate, and use plates with different cross-sectional shapes and sizes at different positions of the cab skin; S200, performing initial profiling on the plate using a first mold, wherein the first mold is a wooden mold; S300, performing secondary pressing on the plate after the initial pressing using a second mold, wherein the second mold is a steel mold; S400, using the first mold to reshape the plate after the secondary pressing to obtain a skin part; S500, assembling and welding the skin parts to obtain a variable-section aluminum honeycomb panel cab skin.

2. The method for forming a variable cross-section aluminum honeycomb panel cab skin according to claim 1, characterized in that: In step S100, different positions of the cab skin have different performance requirements, including sound insulation, rigidity, impact resistance, lightness and bending strength, and the performance and the plate size meet the following requirements: The thickness of the aluminum honeycomb core material, the thickness of the panel, and the side length of the honeycomb holes of the aluminum honeycomb core material decrease, and the sound insulation tends to increase; As the thickness of the aluminum honeycomb core material, the thickness of the panel, and the side length of the honeycomb holes of the aluminum honeycomb core material increase, the impact resistance tends to increase; The smaller the surface density, the higher the degree of lightweight; As the ratio of the wall thickness of the aluminum honeycomb core material to the side length of the honeycomb cells increases, the bending strength and stiffness both tend to increase.

3. The method for forming a variable cross-section aluminum honeycomb panel driver's cab skin according to claim 1 or 2, characterized in that: In the step S100, the cross-sectional shape of the plate includes a sandwich type, a corrugated type, a cellular type, a cone type, a curved surface type, a heterogeneous metal type, and a locally reinforced type.

4. The method for forming a variable cross-section aluminum honeycomb panel cab skin according to claim 1, characterized in that: In the step S200 and the step S400, the pressing pressure of the first mold is 80-160t, the pressing speed is 50-80mm / s, the pressure release time and the pressure holding time are 25-50s, and the standing time is 4-10min.

5. The method for forming a variable cross-section aluminum honeycomb panel cab skin according to claim 4, characterized in that: During the initial pressing process, When the pressing pressure is 80-95t, the pressing speed is 50-70mm / s, the pressure relief time and pressure holding time are 35-50s, and the static time is 5-10min; when When the forming pressure is 90-160t, the pressing speed is 60-80mm / s, the pressure relief time and the pressure holding time are 25-30s, and the standing time is 7-10min; wherein, R represents the inner arc radius of the skin part, and T represents the thickness of the skin part.

6. The method for forming a variable cross-section aluminum honeycomb panel cab skin according to claim 4, characterized in that: During the modification process, When the pressing pressure is 80-90t, the pressing speed is 50-60mm / s, the pressure relief time and pressure holding time are 25-50s, and the static time is 7-10min; The pressing pressure is 90-120t, the pressing speed is 60-70mm / s, the pressure relief time and the pressure holding time are 25-30s, and the standing time is 7-10min; wherein R represents the inner arc radius of the skin part, and T represents the thickness of the skin part.

7. The method for forming a variable cross-section aluminum honeycomb panel cab skin according to claim 1, characterized in that: In the step S300, the pressing pressure of the second mold is 70-120t, the pressing speed is 40-50mm / s, the pressure release time and the pressure holding time are 25-30s, and the standing time is 2-5min.

8. The method for forming a variable cross-section aluminum honeycomb panel cab skin according to claim 7, characterized in that: During the secondary pressing process, When the pressing pressure is 70-80t, the pressing speed is 40-50mm / s, the pressure relief time and pressure holding time are 25-30s, and the static time is 2-5min; When the pressing pressure is 80-120t, the pressing speed is 40-50mm / s, the pressure relief time and the pressure holding time are 25-30s, and the standing time is 2-5min; wherein R represents the inner arc radius of the skin part, and T represents the thickness of the skin part.

9. The method for forming a variable cross-section aluminum honeycomb panel cab skin according to claim 1, characterized in that: In the step S500, adjacent skin parts are spliced ​​together by means of profiles, grooves are provided at the joints of the skin parts, and ends of the profiles are embedded in the grooves and welded.

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