A method for bending and forming a wide-side aluminum alloy profile component

Abstract

The present invention discloses a method for bending and forming a wide-side aluminum alloy profile component, which relates to the field of bending and forming technology and includes the following steps: determining the elongation and wall thickness reduction of the extended part of the component body, modifying the die surface spacing between the side bending punch and the bending die according to the above-mentioned wall thickness reduction, placing the component blank into the mold cavity and bending it, and after the component is bent and formed, keeping the main bending punch and the bending die stationary, continuing to press down the side bending punch until the elongation of the component side is the same as the elongation of the component body, opening the mold, and taking out the component. By increasing the elongation of the component side, the elongation of the component side is made consistent with the elongation of the component body, eliminating the side bending defect of the component, reducing the cross-sectional distortion of the component body caused by side bending, and greatly improving the contour accuracy of such components after forming. No external force is required, the production process of such components is reduced, and the production cycle of such components is accelerated.

Description

Technical Field

[0001] The invention relates to the technical field of bending and forming, in particular to a bending and forming method for a wide-side aluminum alloy profile component. Background Art

[0002] Rail transit refers to a type of vehicle or transportation system in which operating vehicles need to travel on specific tracks. The skeleton components on rail vehicles are generally large in size, and press bending technology is mainly used to bend the profiles. Press bending is a cold working method. The component is bent along the die due to pressure along the bending direction. The press bending process involves fewer processing steps, fast processing speed, and low processing cost, making it suitable for the rapid production of large quantities of workpieces.

[0003] In the existing bending forming technology, during the forming process, the component is bent by the die under the force, and the bent part of the component rotates around the neutral layer of the component deformation. Due to the large difference in the appearance of the component body and the component side, the neutral layers of the component body and the component side are not consistent. Among them, the neutral layer of the component body is located near the center of the component body, and the neutral layer of the component side is located near the center of the component side. The two ends of the component body are far away from the neutral layer of the component body. The radius of rotation around the neutral layer during bending forming is large, resulting in a large amount of deformation. The two ends of the component side are very close to the neutral layer of the component side. When the neutral layer rotates, the rotation radius is very small, resulting in a small deformation. However, the side of the component is located at a position where the elongation of the component body is large. The large difference in the elongation of the two causes the component to generate a lateral force in the direction perpendicular to the press-bending forming and in the transition area between the component body and the side of the component. The direction of the force is from the component body to the side of the component, which eventually leads to a lateral bending defect of the component. The force that causes the lateral bending of the component does not act on the geometric center of the component body, but on the transition area between the component body and the side of the component. This will generate a torque in the main part of the component, and this torque will cause the cross-sectional distortion of the component body.

[0004] When bending narrow-side aluminum alloy profile components using the above-mentioned prior art, the lateral bend defect of the component is small, and the component profile accuracy requirements can be met. When bending medium-width aluminum alloy profile components, the lateral bend defect of the component is large, and the component profile accuracy requirements cannot be met. The prior art applies an external force to the formed component to correct the part. When correcting the component using the prior art, the external force is transmitted to the component side through the transition area between the main body and the side of the component. Due to the rigidity of the component side itself, a moment is generated on the component body that resists the correction of the component. This moment acts in the same position and direction as the moment causing the lateral bend mentioned above, which will aggravate the cross-sectional distortion of the component body. However, the aggravated cross-sectional distortion of the component body can still meet the component profile accuracy requirements. When bending wide-side aluminum alloy profile components using the prior art, the lateral bend defect of the component is large. When applying an external force to correct the formed component, due to the large rigidity of the side, the cross-sectional distortion of the component body is greatly aggravated, and the component profile accuracy cannot meet the processing requirements. Summary of the Invention

[0005] The object of the present invention is to provide a method for bending and forming a wide-side aluminum alloy profile component to solve the problems raised by the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A method for bending a wide-side aluminum alloy profile member comprises the following steps:

[0008] 1) Determine the elongation and wall thickness reduction of the main elongated part of the component, record the wall thickness of each part of the bent part of the component, and modify the die face distance between the side bending punch and the bending die according to the above wall thickness reduction;

[0009] 2) The component blank is placed into the mold cavity, and the main body bending punch and the side bending punch are lowered at the same time to bend the component. When the main body of the component is bent, the side of the component fits with the die surface of the bending die and contacts the lowest point of the die surface of the side bending punch.

[0010] 3) Keep the main bending punch and the bending die stationary, continue to press down the side bending punch until the elongation of the component side is the same as the elongation of the component body, open the mold and take out the component.

[0011] On the basis of the above technical solutions, the present invention also provides the following optional technical solutions:

[0012] In an optional solution: in step 2), the bending mold includes a main bending punch, a side bending punch, a bending die, a baffle and a limit plate, and a cavity for component forming is formed between the main bending punch, the side bending punch and the bending die.

[0013] In an optional solution: in step 3), after the component is formed, the main bending punch and the bending die are kept stationary, and the bending stroke of the side bending punch is continued to be increased. By transitionally extruding the bent part of the side of the component, the thinning amount of the side of the component is increased, and then the elongation of the side of the component is increased, so that the elongation of the side of the component is consistent with that of the component body.

[0014] In an optional solution: the baffle is connected to the side bending punch through bolts, and the baffle is used to limit the flow direction of the sheet metal on the side of the component.

[0015] In an optional solution: a reserved hole for connecting a limit plate is provided on the main body bending punch, and the limit plate is connected to the main body bending punch by bolts, and the limit plate is used to limit the sliding direction of the component.

[0016] In an optional solution, the basis for the reduction in the distance between the side bending punch and the side bending die is the amount of thinning that should occur at various locations on the side of the component after bending.

[0017] In an optional solution: the basis for the thinning amount at various locations on the side of the component after press-bending is the thinning amount at various locations on the component body after press-bending. The thinning amount at various locations on the component body after press-bending can be determined by equivalent experiments or numerical simulation methods.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The present invention is a method for bending and forming wide-side aluminum alloy profile components. By increasing the elongation of the component side, the elongation of the component side is made consistent with the elongation of the component body, thereby eliminating the lateral bending defect of the component and greatly improving the contour accuracy of such components after forming. The press-bending forming method can not only greatly increase the contour accuracy of wide-side aluminum alloy after bending and forming, but can also be used to improve the contour accuracy of narrow-side aluminum alloy profiles or medium-width side aluminum alloy profiles.

[0020] 2. Compared with existing bending forming technologies, the source of the torque for eliminating the lateral bending defect of the component in the present invention is the internal stress of the component deformation, without the need to apply external force, which reduces the production process of such components, speeds up the production cycle of such components, and reduces the production cost of such components.

[0021] 3. Compared with existing bending forming technologies, the forming process provided by the present invention generates a moment on the main body of the component when the side of the component is elongated. The moment acts at the same position as the moment causing lateral bending of the component, but in the opposite direction. The torque generated by this moment on the main body of the component will reduce the cross-sectional distortion of the main body of the component caused by lateral bending, thereby further improving the contour accuracy of such components after forming. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the bending forming die for wide side aluminum alloy profile components.

[0023] Figure 2 After the component is press-bent Figure 1 Cross-sectional view at BB.

[0024] Figure 3 The schematic diagram shows the principle of the bending forming method of the wide side aluminum alloy profile member.

[0025] Figure 4 A structural diagram of the component.

[0026] Figure 5 A cross-sectional view of a component.

[0027] Figure 6 Schematic diagram of the cross section of the main tensile part of the component.

[0028] Figure 7 Schematic diagram of the mold of the present invention before pressing down.

[0029] Figure 8 Schematic diagram of the mold of the present invention during bending.

[0030] Figure 9 Schematic diagram of the mold of the present invention after bending.

[0031] Figure 10 For components in Figure 8 Cross-sectional view at CC.

[0032] Figure 11 For components in Figure 9 Cross-sectional view at DD.

[0033] Figure 12 These are the results of numerical simulation of press-bending forming of components using traditionally designed dies.

[0034] Figure 13 This is the result of numerical simulation of press-bending forming of components using the mold designed by the present invention.

[0035] Notes on the figure marks: 1-component body, 1.1-neutral layer of component body, 1.2-section of tensile part of component body, 2-component side, 2.1-neutral layer of component side, 2.2-transition area between component body and component side, 3-main body bending punch, 3.1-limiting plate, 4-side bending punch, 4.1-baffle, 5-bending die, 6-cavity, 7-bolt. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0037] The specific implementation of the present invention is described in detail below with reference to specific embodiments.

[0038] like Figure 1-11 As shown, a method for bending a wide-side aluminum alloy profile member provided by one embodiment of the present invention is provided. The member is composed of a closed square-shaped member body 1 and a plate-shaped member side 2, and includes the following steps:

[0039] 1) According to the actual production situation, determine the elongation of the elongated part 1.2 of the component body 1 and the wall thickness reduction, see Figure 6 As shown, the wall thickness of the bent portion of the component is recorded. According to the recorded wall thickness, the die surface of the side bending punch 4 is adjusted so that the distance between the die surface of the side bending die 5 and the die surface is equal to the wall thickness of the extended portion 1.2 of the component body 1;

[0040] 2) Lift the side bending punch 4. The lifting height is the difference between the maximum and minimum distances between the side bending punch 4 and the bending die 5. Adjust the position of the main bending punch 3 to the position where the bending die 5 is closed. At the same time, lift the main bending punch 3 to the same stroke as the side bending punch 4. Place the component blank into the mold cavity. The component position is as follows: Figure 7 As shown, the main body bending punch 3 and the side bending punch 4 descend and bend the component. When the component body 1 is bent, see Figure 8 As shown, the side edge 2 of the component is in contact with the die surface of the bending die 5 and is in contact with the lowest point of the die surface of the side bending punch 4. Figure 10 As shown;

[0041] 3) Keep the main bending punch 3 and the bending die 5 stationary, and continue to press the side bending punch 4 until the elongation of the component side 2 is the same as the elongation of the component body 1, see Figure 9 As shown, at this time, the side edge 2 of the component is transitionally squeezed, see Figure 11 As shown;

[0042] 4) Open the mold, take out the component, lift the side bending punch 4, the lifting height is the difference between the maximum and minimum values ​​of the distance between the die surfaces of the side bending punch 4 and the bending die 5, and at the same time lift the main bending punch 3 and the side bending punch 4 to the same stroke, put in the next blank of this component, repeat the cycle, and complete the mass production of this component.

[0043] like Figure 1As shown, as a preferred embodiment of the present invention, in step 2), the bending mold includes a main bending punch 3, a side bending punch 4, a bending die 5, a baffle 4.1 and a limit plate 3.1, and a cavity 6 for component forming is formed between the main bending punch 3, the side bending punch 4 and the bending die 5.

[0044] like Figure 1 As shown, as a preferred embodiment of the present invention, in step 3), after the component is formed, the main body bending punch 3 and the bending die 5 are kept stationary, and the bending stroke of the side bending punch 4 is continued to be increased. By the method of transitionally extruding the side bending part of the component, the thinning amount of the component side 2 is increased, and then the elongation of the component side 2 is increased, so that the elongation of the component side 2 is consistent with that of the component main body 1.

[0045] like Figure 1 As shown, as a preferred embodiment of the present invention, the baffle 4.1 is connected to the side bending punch 4 by bolts, and the baffle 4.1 is used to limit the flow direction of the sheet material on the side 2 of the component. If there is no restriction, the flow direction of the sheet material will be arbitrary. With the baffle 4.1, the flow of the sheet material in the width direction of the component can be limited, thereby strengthening the flow of the sheet material along the length direction. The component will not be displaced in the direction of the baffle 4.1, and the side bending punch 4 and the main part of the component will limit the displacement of the component in the direction of the baffle 4.1; the main bending punch 3 is provided with a reserved hole for connecting the limit plate 3.1, and the limit plate 3.1 is connected to the main bending punch 3 by bolts to limit the displacement of the component in the direction of the limit plate 3.1.

[0046] like Figure 1-6 As shown, as a preferred embodiment of the present invention, the basis for the reduction in the distance between the die surfaces of the side bending punch 4 and the bending die 5 is the amount of thinning that should occur at various locations on the side of the component after press-bending forming; the basis for the amount of thinning that should occur at various locations on the side of the component 2 after press-bending forming is the amount of thinning that should occur at various locations on the component body 1 after press-bending forming; the amount of thinning at various locations on the component body 1 after press-bending forming can be determined by equivalent experiments, numerical simulations and the like.

[0047] like Figure 1-2 As shown, as a preferred embodiment of the present invention, the main body bending punch 3 and the side bending punch 4 are two independent parts of the bending punch separated along the transition area 2.2 between the component body 1 and the component side 2; the die surface adjustment method of the side bending punch 4 is to reprocess the die surface by machining; the method for controlling the lifting height and bending stroke of the main body bending punch 3 and the side bending punch 4 is to control them by using the stroke limit of the press; the method for controlling the different lifting heights and different bending strokes of the main body bending punch 3 and the side bending punch 4 can be to use a double-action press or a mold with a spring.

[0048] The above embodiment of the present invention provides a method for bending and forming a wide-side aluminum alloy profile member. The thinning of the side wall thickness of the member caused by excessive extrusion will increase the flow of the member side 2 in all directions. The limiting plate 3.1 and the baffle 4.1 are used to suppress the sheet material flow of the member side 2 along the width direction of the member, so that the sheet material flow of the member side 2 is carried out along the length direction of the member. Figure 3 As shown, the limit plate 3.1 and the baffle 4.1 should not be too thin. The function of the limit plate and the baffle is to limit the flow along the width direction of the component side, which requires sufficient rigidity. Too thin limit plates and baffles cannot provide sufficient rigidity.

[0049] The limiting plate 3.1 should not be too short. During the component bending forming process, the bending punch is constantly moving. Before the side 2 of the component is over-extruded, the bending forming of the component is already in progress. At this time, the component itself has already produced a lateral bending defect. Due to the existence of the baffle 4.1, the component will be displaced by the force of the baffle 4.1, and the displacement direction is in the opposite direction of the lateral bending. At this time, the component will come into contact with the moving mold and generate a force. If the limiting plate 3.1 does not completely cover the component at this time, it will scratch the outer surface of the component, seriously affecting the contour accuracy of the component after forming.

[0050] The finite element simulation method is used to perform numerical simulation. The target component is press-bent using the traditional forming method and the forming method of the present invention. The numerical simulation results show that the forming method of the present invention can significantly reduce the side bending defects of the target component. The numerical simulation results of the press-bending forming of the component using the traditional forming method are shown in FIG. Figure 12 As shown; the numerical simulation results of the bending forming of the component using the forming method of the present invention are shown in Figure 13 shown.

[0051] The above description is merely a specific embodiment of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this disclosure should be included in the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. A method for bending a wide-side aluminum alloy profile member, characterized in that: The bending die includes a main bending punch, a side bending punch, a bending die, a baffle and a limit plate. A cavity for component forming is formed between the main bending punch, the side bending punch and the bending die. The bending forming method includes the following steps: 1) Determine the elongation and wall thickness reduction of the main elongated part of the component, record the wall thickness of the bent part of the component, and adjust the die surface of the side bending punch according to the wall thickness so that the distance between it and the die surface of the bending die is equal to the wall thickness of the main elongated part of the component; 2) Place the component blank into the mold cavity, and simultaneously lower the main bending punch and the side bending punch to bend the component. When the main body of the component is bent, the side of the component fits into the die surface of the bending die and contacts the lowest point of the die surface of the side bending punch. 3) Keep the main bending punch and the bending die stationary, continue to press down the side bending punch until the elongation of the component side is the same as the elongation of the component body, open the mold and take out the component.

2. The method for bending a wide-side aluminum alloy profile member according to claim 1, characterized in that: In step 3), after the component is formed, the main bending punch and the bending die are kept stationary, and the bending stroke of the side bending punch is continued to be increased. By transitionally extruding the bent part of the side of the component, the thinning amount of the side of the component is increased, and then the elongation of the side of the component is increased, so that the elongation of the side of the component is consistent with that of the main body of the component.

3. The method for bending a wide-side aluminum alloy profile member according to claim 1, wherein: The baffle is connected to the side bending punch through bolts, and the baffle is used to limit the flow direction of the sheet metal on the side of the component.

4. The method for bending a wide-side aluminum alloy profile member according to claim 3, characterized in that: The main body bending punch is provided with a reserved hole for connecting a limit plate. The limit plate is connected to the main body bending punch by a bolt. The limit plate is used to limit the sliding direction of the component.

5. The method for bending a wide-side aluminum alloy profile member according to claim 1, characterized in that: The basis for the reduction in the distance between the side bending punch and the bending die surface is the thinning amount that should be achieved at various locations on the side of the component after bending.

6. The method for bending a wide-side aluminum alloy profile member according to claim 1, wherein: The basis for the thinning amount at each location of the component side after press-bending is the thinning amount at each location of the component body after press-bending. The thinning amount at each location of the component body after press-bending can be determined by equivalent experiments or numerical simulation methods.

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