Bending forming method for wide-side-edge aluminum alloy profile component

Abstract

The invention discloses a bending forming method for a wide-side aluminum alloy profile component, which relates to the technical field of bending forming and comprises the following steps of: determining the elongation and the wall thickness reduction of an elongation part of a component main body, modifying the distance between the die surfaces of a side bending male die and a bending female die according to the wall thickness reduction, and forming the wide-side aluminum alloy profile component according to the distance between the die surfaces of the bending male die and the bending female die. And a component blank is put into the mold cavity and bent, after the component is bent and formed, the main body bending male mold and the bending female mold are kept immovable, the side edge bending male mold is continuously pressed till the extension amount of the side edge of the component is the same as the extension amount of the main body of the component, the mold is opened, and the component is taken out. By increasing the elongation of the side edge of the component, the elongation of the side edge of the component is consistent with the elongation of the component main body, so that the sidewise bending defect of the component is eliminated, the section distortion of the component main body generated during sidewise bending of the component is reduced, the contour precision of the formed component is greatly improved, external force does not need to be applied, and the production procedures of the component are reduced; and the production period of the component 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 transportation 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 the profiles are mainly bent using press bending technology. Press bending is a cold processing method. The components are bent along the mold due to pressure along the bending direction. The press bending process involves fewer processing steps, fast processing speed, and low processing cost, which is suitable for rapid production of large quantities of workpieces.

[0003] In the existing bending forming technology, during the forming process, the component is subjected to force and bends with the die, 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 side of the component, the neutral layers of the component body and the side of the component 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 side of the component is located near the center of the side of the component. 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, while the two ends of the side of the component are very close to the neutral layer of the side of the component, and they rotate around the neutral layer during press bending. 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 main body of the component 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 main body of the component and the side of the component. The direction of the force is from the main body of the component to the side of the component, which ultimately 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 main body of the component, but on the transition area between the main body of the component 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 main body of the component.

[0004] When the above-mentioned prior art bends and forms narrow-side aluminum alloy profile components, the lateral bending defects of the components are small, which can meet the contour accuracy requirements of the components; when the medium-width side aluminum alloy profile components are bent and formed, the lateral bending defects of the components are large, which cannot meet the contour accuracy requirements of the components. The prior art uses the method of applying external force to the formed components to make the parts return to the right position. When the prior art returns the components, the external force will be transmitted to the side of the component through the transition area between the main body and the side of the component. Since the side of the component itself has rigidity, a moment resisting the return of the component will be generated on the main body of the component. The moment has the same position and direction as the moment causing the lateral bending of the component, which will aggravate the cross-sectional distortion of the main body of the component, but the aggravated cross-sectional distortion of the main body of the component can still meet the contour accuracy requirements of the component; when the prior art bends and forms wide-side aluminum alloy profile components, the lateral bending defects of the components are large. When the external force is applied to the formed components to return the components, due to the large side stiffness, the cross-sectional distortion of the main body of the component will be greatly aggravated, so that the contour accuracy of the component 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 member 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 surface spacing 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 bending of the component is completed, the side of the component fits with the die surface of the bending die and contacts with 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 side of the component is the same as the elongation of the main body of the component, open the mold and take out the component.

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

[0012] In an optional scheme: in step 2), the bending mold includes a main body 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 body bending punch, the side bending punch and the bending die.

[0013] In an optional scheme: in step 3), after the component is formed, the main body bending punch and the bending die are kept stationary, and the bending stroke of the side bending punch 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 is increased, and then the elongation of the component side is increased, so that the elongation of the component side is consistent with that of the component body.

[0014] In an optional solution: the baffle is connected to the side bending punch by 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 surface 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 a wide-side aluminum alloy profile 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, 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 the wide-side aluminum alloy after bending and forming, but can also be used to improve the bending and forming contour accuracy of narrow-side aluminum alloy profiles or medium-width side aluminum alloy profiles.

[0020] 2. Compared with the existing bending forming technology, 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, and no external force needs to be applied, 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 the existing bending forming technology, the forming process provided by the present invention will generate a moment on the main body of the component when the side of the component is elongated. The moment has the same acting position as the moment causing lateral bending of the component, but is opposite in direction. The torque generated by the moment on the main part of the component will reduce the cross-sectional distortion of the main body of the component caused by lateral bending of the component, thereby further improving the contour accuracy of such components after forming. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0024] Figure 3 The schematic diagram is a method for bending and forming wide side aluminum alloy profile components.

[0025] Figure 4 A schematic diagram of the structure 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 It is a schematic diagram of the mold of the present invention before pressing down.

[0029] Figure 8 It is a schematic diagram of the mold of the present invention during bending.

[0030] Fig. 9 It is a schematic diagram of the mold of the present invention after bending.

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

[0032] Fig.11 For components in Fig. 9 Sectional view at DD.

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

[0034] Fig.13 The figure is the result of numerical simulation of press-bending of components using the mold designed by the present invention.

[0035] Notes on figure numbers: 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 solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with 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 in conjunction with specific embodiments.

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

[0039] 1) According to the actual production situation, determine the elongation and wall thickness reduction of the elongated part 1.2 of the component body 1, see Figure 6 As shown, the wall thickness of the bent part of the component is recorded, and according to the recorded wall thickness, the die surface of the side bending punch 4 is adjusted so that the distance between it and the die surface of the bending die 5 is equal to the wall thickness of the elongated part 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. Put 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 bending of the component body 1 is completed, 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 die 4, see Fig.10 As shown;

[0041] 3) Keep the main bending punch 3 and the bending die 5 stationary, and continue to press down 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 Fig. 9 As shown, at this time, the side edge 2 of the component is overextended, see Fig.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 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 body 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 body 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 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 metal on the side 2 of the component. If there is no restriction, the flow direction of the sheet metal will be arbitrary. With the baffle 4.1, the flow of the sheet metal in the width direction of the component can be limited, thereby strengthening the flow of the sheet metal 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 body of the component will limit the displacement of the component in the direction of the baffle 4.1; the main body 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 body 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 the side of the component should have at various locations after press-bending; the basis for the amount of thinning that the side 2 of the component should have at various locations after press-bending is the amount of thinning of the component body 1 at various locations after press-bending; the amount of thinning of the component body 1 at various locations after press-bending 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 separated by the bending punch 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-acting 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 the excessive extrusion will increase the flow of the side 2 of the member in all directions. The limiting plate 3.1 and the baffle 4.1 are used to suppress the sheet flow of the side 2 of the member in the width direction of the member, so that the sheet flow of the side 2 of the member is carried out along the length direction of the member. Figure 3 As shown, the limit plate 3.1 and the baffle plate 4.1 should not be too thin. The function of the limit plate and the baffle plate is to limit the flow of the side edge of the component along the width direction of the component, which requires sufficient rigidity. Too thin limit plates and baffle plates cannot provide sufficient rigidity.

[0049] The limit plate 3.1 should not be too short. During the component bending process, the bending punch moves continuously. Before the side 2 of the component is excessively squeezed, the component is already bending. 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 contact the moving mold and generate a force. If the limit 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, and 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 greatly 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. Fig.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 Fig.13 shown.

[0051] The above is only a specific implementation of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A method for bending a wide-side aluminum alloy profile member, characterized in that: The steps include: 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 surface spacing between the side bending punch and the bending die according to the above wall thickness reduction; 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 bending of the component is completed, the side of the component fits with the die surface of the bending die and contacts with 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 side of the component is the same as the elongation of the main body of the component, 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 2), the bending die comprises a main body 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 body bending punch, the side bending punch and the bending die.

3. 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.

4. The method for bending a wide side aluminum alloy profile member according to claim 2, characterized in that: 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.

5. The method for bending a wide side aluminum alloy profile member according to claim 4, 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 bolts, and the limit plate is used to limit the sliding direction of the component.

6. 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 side bending die surface is the amount of thinning that should occur at various locations on the side of the component after bending.

7. The method for bending a wide-side aluminum alloy profile member according to claim 1, characterized in that: The basis for the thinning amount at various locations on the side of the component after press-bending forming is the thinning amount at various locations on the component body after press-bending forming. The thinning amount at various locations on the component body after press-bending forming can be determined by equivalent experiments or numerical simulation methods.

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