A method for determining the manufacturability of sheet metal bending

Abstract

The present invention relates to the technical field of automotive parts, and specifically to a method for determining the manufacturability of sheet metal tube bending. Based on the bending deformation mechanism of the material, the bending deformation characteristics of the material are correlated with the bending deformation characteristic parameters of the part, and the microscopic deformation mechanism during the bending process is used to accurately predict the bending characteristics of the part. The present invention can scientifically and accurately predict bending cracks in metal sheet tube parts, overcoming the technical difficulty that traditional empirical methods cannot determine high-strength materials, greatly improving the prediction accuracy of the bending deformation of parts, and is very suitable for determining occasions with multiple parts with different bending characteristics, and widely meets the application requirements of engineering practice and scientific research work.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile parts, in particular to a method for determining the manufacturability of a plate-bent pipe. Background Art

[0002] In the automotive parts manufacturing process, after sheet metal is formed into square or round tubes, it is often bent into various angles to meet the application requirements of the parts. However, during the bending process, the sheet metal undergoes various deformation states, such as tension and compression, which can easily cause cracks to form and cause the parts to break. Once cracked, the stiffness and strength of the parts will be significantly reduced, and they will no longer meet the requirements of the parts.

[0003] Currently, existing technical approaches in the industry rely primarily on empirical methods to select low-strength materials with higher elongation at break to avoid cracking during bending. However, due to the relatively low elongation at break of high-strength steel, cracking often occurs when using high-strength steel to manufacture pipe components. Traditional empirical methods are no longer sufficient to meet actual engineering requirements. Therefore, it is crucial to develop a method to determine the manufacturability of sheet metal pipe bending. Summary of the Invention

[0004] In order to overcome the shortcomings of the existing technology, the present invention provides a method for determining the manufacturability of sheet metal pipe bending, which can scientifically and accurately predict the bending cracks of metal sheet tube parts and determine whether the sheet metal can meet the manufacturing requirements of the bent parts.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for determining the manufacturability of a plate-bent pipe comprises the following steps:

[0007] 1) Identify the cross-sectional features of the part and measure the minimum bending radius inside the cross-sectional area of ​​the part as R 截面内弯min , unit mm; the minimum bending radius outside the part section is R 截面外弯min , unit mm; the maximum bending angle of the part section is α 截面max , unit °;

[0008] 2) Identify the overall contour of the part and measure the minimum bending radius of the inner side of the part's bend as R 整体内弯min , unit mm; the minimum bending radius of the outer side of the part is R 整体外弯min , unit mm; the maximum bending angle of the part is α 整体max , unit °;

[0009] 3) If R 截面内弯min <R 整体内弯min, then the rectangular sheet is made in such a way that the rolling direction of the sheet is perpendicular to the center line of the bending radius;

[0010] If R 截面内弯min >R 整体内弯min , then the rectangular sheet is made in such a way that the rolling direction of the sheet is parallel to the center line of the bending radius;

[0011] Punch radius and R 截面内弯min Adapt to the sheet metal 截面max °Bending test, the limit strain at the outer bending radius of the sheet is measured as ε;

[0012] 4) Process the uniaxial tensile specimen in the direction of the rectangular sheet material in step 3). The width of the deformation area in the middle of the dumbbell-shaped uniaxial tensile specimen satisfies:

[0013] L w ≥2.5×(R 整体内弯min +t);

[0014] Where: L w is the width of the deformation area in the middle of the dumbbell-shaped uniaxial tensile specimen, mm;

[0015] R 整体内弯min The minimum bending radius of the inner side of the part, mm;

[0016] t is the thickness of the part, mm;

[0017] The tensile test specimen is stretched to the ultimate strain measured in step 3) and then the stretching is stopped;

[0018] 5) Process the deformed area of ​​the tensile specimen in step 4) into a rectangular sheet. The direction of the extension line of the bending radius of the sheet is opposite to that in step 3). The punch radius is the same as R 整体内弯min Adapt to the sheet metal 整体max °Bending test;

[0019] 6) If cracks appear in the sheet during the bending test in step 3) or step 5), the current sheet cannot meet the use requirements and needs to be replaced with a material with better bending performance;

[0020] If no cracks appear in the sheet material during the bending tests in step 3) and step 5), the current sheet material can meet the manufacturing requirements of the bent part.

[0021] Furthermore, in step 1), the part is a bent tube with a rectangular cross-section.

[0022] Furthermore, in step 3), if R 截面内弯min >R 整体内弯min , the rectangular sheet is made in such a way that the rolling direction of the sheet is parallel to the center line of the bending radius.

[0023] Furthermore, in step 3), the sheet material is a metal sheet material.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention discloses a method for determining the manufacturability of sheet metal tube bends. Based on the material bending deformation mechanism, the method correlates the material's bending deformation characteristics with the bending deformation characteristic parameters of the component, and accurately predicts the bending characteristics of the component using the microscopic deformation mechanism during the bending process. This method can scientifically and accurately predict bending cracks in sheet metal tube components, overcoming the technical difficulty of traditional empirical methods in determining high-strength materials. It significantly improves the accuracy of component bending deformation prediction and is highly suitable for determining components with multiple different bending characteristics, widely meeting the application requirements of practical engineering and scientific research. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the three-dimensional structure of an embodiment of the present invention.

[0027] Figure 2 It is a cross-sectional characteristic diagram of an embodiment of the present invention.

[0028] Figure 3 It is a contour feature diagram of an embodiment of the present invention.

[0029] Figure 4 It is a cross-sectional bending specimen diagram of an embodiment of the present invention.

[0030] Figure 5 It is a characteristic diagram of the tensile specimen of an embodiment of the present invention.

[0031] Figure 6 Schematic diagram of a contour bending test according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The present invention discloses a method for determining the manufacturability of sheet metal pipe bends. Those skilled in the art may refer to the contents herein and appropriately modify the process parameters to achieve the desired results. It is particularly important to note that all similar substitutions and modifications obvious to those skilled in the art are considered encompassed by the present invention. The methods and applications of the present invention have been described through preferred embodiments. It is apparent that those skilled in the art can modify, alter, and combine the methods and applications described herein to implement and apply the technology of the present invention without departing from the content, spirit, and scope of the present invention.

[0033] A method for determining the manufacturability of sheet metal tube bending is based on the material bending deformation mechanism. The bending deformation characteristics of the material are correlated with the bending deformation characteristic parameters of the part. The microscopic deformation mechanism during the bending process is used to accurately predict the bending characteristics of the part. The specific steps are as follows:

[0034] 1. Identify the cross-sectional features of the part, measure the inner and outer bending radius and bending angle at the position with typical cross-sectional features, and determine the minimum bending radius and maximum bending angle in the typical cross-sectional features of the part. The minimum bending radius inside the part cross-sectional features is measured as R 截面内弯min , unit mm; the minimum bending radius outside the part section is R 截面外弯min , unit mm; the maximum bending angle of the part section is α 截面max , unit: °.

[0035] 2. Identify the overall contour features of the part, measure the inner and outer bending radius and bending angle of the part with bending features, and determine the minimum bending radius and maximum bending angle of the overall bending features of the part. The minimum bending radius of the inner side of the part is measured to be R 整体内弯min , unit mm; the minimum bending radius of the outer side of the part is R 整体外弯min , unit mm; the maximum bending angle of the part is α 整体max , unit: °.

[0036] 3. If the minimum bending radius in the cross-sectional feature is smaller than the minimum bending radius in the profile feature, a rectangular sheet is made in such a way that the rolling direction of the sheet is perpendicular to the center line of the bending radius. If the minimum bending radius in the cross-sectional feature is larger than the minimum bending radius in the profile feature, a rectangular sheet is made in such a way that the rolling direction of the sheet is parallel to the center line of the bending radius. The punch radius is selected according to the inner minimum bending radius determined in step 1. The sheet is subjected to a bending test at the maximum bending angle determined in step 1, and the ultimate strain at the outer bending radius of the sheet is measured.

[0037] If R 截面内弯min <R 整体内弯min , the rectangular sheet is made in such a way that the rolling direction of the sheet is perpendicular to the center line of the bending radius; if R 截面内弯min >R 整体内弯min , the rectangular sheet is made in such a way that the rolling direction of the sheet is parallel to the center line of the bending radius. 截面内弯min Adapt to the sheet metal 截面max °Bending test, the ultimate strain at the outer bending radius of the sheet is measured as ε.

[0038] 4. Process the uniaxial tensile specimen in the direction of the rectangular sheet in step 3. The width of the deformation area in the middle of the dumbbell-shaped uniaxial tensile specimen needs to meet the requirement of Lw≥2.5×(R min轮廓 +t), that is, the width must be greater than 2.5 times the minimum bending radius determined in step 2 plus 2 times the material thickness. The tensile specimen is stretched to the ultimate strain measured in step 3 and then the stretching is stopped.

[0039] That is, the uniaxial tensile specimen is processed according to the rectangular sheet manufacturing direction of step 3, and the width of the deformation area in the middle of the dumbbell-shaped uniaxial tensile specimen meets the following requirements:

[0040] L w ≥2.5×(R 整体内弯min +t);

[0041] Where: L w is the width of the deformation area in the middle of the dumbbell-shaped uniaxial tensile specimen, mm;

[0042] R 整体内弯min The minimum bending radius of the inner side of the part, mm;

[0043] t is the thickness of the part, mm;

[0044] The tensile test specimen is stretched to the ultimate strain measured in step 3) and then the stretching is stopped. 整体内弯min Equal to R min轮廓 .

[0045] 5. Process the deformed area of ​​the tensile specimen in step 4 into a rectangular sheet. The direction of the extension line of the bending radius of the sheet is opposite to that of step 3. Select the punch radius according to the minimum inner bending radius determined in step 2. Perform a bending test on the sheet according to the maximum bending angle determined in step 2. Process the deformed area of ​​the tensile specimen in step 4 into a rectangular sheet. The direction of the extension line of the bending radius of the sheet is opposite to that of step 3. Select the punch radius according to the minimum inner bending radius determined in step 2. Perform a bending test on the sheet according to the maximum bending angle determined in step 2. 整体内弯min Adapt to the sheet metal 整体max °Bending test;

[0046] 6. If cracks appear in the sheet during the bending test in step 3 or step 5, the current sheet cannot meet the use requirements and needs to be replaced with a material with better bending performance. If no cracks appear in the bending tests in step 3 or step 5, the current sheet can meet the manufacturing requirements of the bent part.

[0047] [Example 1]

[0048] like Figure 1-6 As shown in the figure, a method for determining the manufacturability of plate bending is Figure 1 Take the bent pipe parts as an example to illustrate, the specific steps include:

[0049] 1. If Figure 2 As shown, the cross-sectional features of the part are identified, and the inner and outer bending radius and bending angle are measured for the locations with typical cross-sectional features. The minimum bending radius of the typical cross-sectional features of the part is determined to be 5mm and the maximum bending angle is 90 degrees. 截面内弯min =5mm, the minimum bending radius outside the part section is R 截面外弯min=6mm, maximum bending angle of part section α 截面max =90°.

[0050] 2. If Figure 3 As shown, the overall contour features of the part are identified, and the inner and outer bending radii and bending angles of the part with bending features are measured. It is determined that the minimum bending radius of the overall bending feature of the part is 24mm and the maximum bending angle is 90 degrees. 整体内弯min =24mm, R 整体外弯min =51mm,α 整体max =90°.

[0051] 3. If Figure 4 As shown in , since the minimum bending radius in the cross-section feature is smaller than the minimum bending radius in the profile feature, the rectangular sheet is made in such a way that the rolling direction of the sheet is perpendicular to the center line of the bending radius, as shown in Figure 4 As shown, according to the minimum inner bending radius determined in step 1, the punch radius is selected to be 5 mm, and a 90-degree bending test is performed on the sheet material according to the maximum bending angle determined in step 1. The ultimate strain at the outer bending radius of the sheet material is measured to be 2.68%.

[0052] 4. Process the uniaxial tensile specimen in the direction of the rectangular sheet in step 3. The width of the deformation area in the middle of the dumbbell-shaped uniaxial tensile specimen needs to meet the requirement of Lw≥2.5×(R min轮廓 +t), that is, the width must be greater than 2.5 times the minimum bending radius determined in step 2 plus 2 times the material thickness, such as Figure 5 As shown, the tensile test specimen is stretched to the ultimate strain of 2.68% measured in step 3 and then the stretching is stopped. The ultimate strain ε at the outer bending radius of the sheet is 2.68%.

[0053] 5. Process the deformed area of ​​the tensile specimen in step 4 into a rectangular sheet. The direction of the extension line of the bending radius of the sheet is opposite to that in step 3, such as Figure 6 As shown, according to the minimum inner bending radius determined in step 2, the punch radius is selected to be 24 mm, and the sheet metal is subjected to a bending test at the maximum bending angle of 90 degrees determined in step 2.

[0054] 6. If no cracks appear on the current sheet in the bending tests in step 3 and step 5, the current sheet can meet the manufacturing requirements of the bent part.

[0055] [Example 2]

[0056] like Figure 1-6 As shown in the figure, a method for determining the manufacturability of plate bending is Figure 1 Take the bent pipe parts as an example to illustrate, the specific steps include:

[0057] 1. If Figure 2As shown, the cross-sectional features of the part are identified, and the inner and outer bending radius and bending angle are measured for the locations with typical cross-sectional features. The minimum bending radius of the typical cross-sectional features of the part is determined to be 20 mm and the maximum bending angle is 120 degrees. 截面内弯min =20mm, the minimum bending radius outside the part section is R 截面外弯min =25mm, maximum bending angle of part section α 截面max =120°.

[0058] 2. If Figure 3 As shown, the overall contour features of the part are identified, and the inner and outer bending radii and bending angles of the bending feature positions of the part are measured. It is determined that the minimum bending radius of the overall bending feature of the part is 18 mm and the maximum bending angle is 135 degrees. 整体内弯min =26mm, R 整体外弯min =36mm,α 整体max =135°.

[0059] 3. If Figure 4 As shown in , since the minimum bending radius in the cross-section feature is smaller than the minimum bending radius in the profile feature, the rectangular sheet is made in such a way that the rolling direction of the sheet is perpendicular to the center line of the bending radius, as shown in Figure 4 As shown, according to the minimum inner bending radius determined in step 1, the punch radius is selected as 20 mm, and the sheet is subjected to a 120-degree bending test according to the maximum bending angle determined in step 1. The ultimate strain at the outer bending radius of the sheet is measured to be 5.66%.

[0060] 4. Process the uniaxial tensile specimen in the direction of the rectangular sheet in step 3. The width of the deformation area in the middle of the dumbbell-shaped uniaxial tensile specimen needs to meet the requirement of Lw≥2.5×(R min轮廓 +t), that is, the width must be greater than 2.5 times the minimum bending radius determined in step 2 plus 2 times the material thickness, such as Figure 5 As shown, the tensile test specimen is stretched to the ultimate strain of 5.66% measured in step 3 and then the stretching is stopped. The ultimate strain ε at the outer bending radius of the sheet is 5.66%.

[0061] 5. Process the deformed area of ​​the tensile specimen in step 4 into a rectangular sheet. The direction of the extension line of the bending radius of the sheet is opposite to that in step 3, such as Figure 6 As shown, according to the minimum inner bending radius determined in step 2, the punch radius is selected to be 26 mm, and the sheet metal is subjected to a bending test at the maximum bending angle of 135 degrees determined in step 2.

[0062] 6. If no cracks appear on the current sheet in the bending tests in step 3 and step 5, the current sheet can meet the manufacturing requirements of the bent part.

[0063] [Example 3]

[0064] like Figure 1-6 As shown in the figure, a method for determining the manufacturability of plate bending is Figure 1 Take the bent pipe parts as an example to illustrate, the specific steps include:

[0065] 1. If Figure 2 As shown, the cross-sectional features of the part are identified, and the inner and outer bending radius and bending angle are measured for the locations with typical cross-sectional features. The minimum bending radius of the typical cross-sectional features of the part is determined to be 10 mm and the maximum bending angle is 110 degrees. 截面内弯min =10mm, the minimum bending radius outside the part section is R 截面外弯min =12mm, maximum bending angle of part section α 截面max =110°.

[0066] 2. If Figure 3 As shown, the overall contour features of the part are identified, and the inner and outer bending radii and bending angles of the part with bending features are measured. The minimum bending radius of the overall bending feature of the part is determined to be 20 mm and the maximum bending angle is 100 degrees. 整体内弯min =20mm, R 整体外弯min =40mm,α 整体max =100°.

[0067] 3. If Figure 4 As shown in , since the minimum bending radius in the cross-section feature is smaller than the minimum bending radius in the profile feature, the rectangular sheet is made in such a way that the rolling direction of the sheet is perpendicular to the center line of the bending radius, as shown in Figure 4 As shown, according to the minimum inner bending radius determined in step 1, the punch radius is selected as 10 mm, and the sheet is subjected to a 110-degree bending test according to the maximum bending angle determined in step 1. The ultimate strain at the outer bending radius of the sheet is measured to be 3.67%.

[0068] 4. Process the uniaxial tensile specimen in the direction of the rectangular sheet in step 3. The width of the deformation area in the middle of the dumbbell-shaped uniaxial tensile specimen needs to meet the requirement of Lw≥2.5×(R min轮廓 +t), that is, the width must be greater than 2.5 times the minimum bending radius determined in step 2 plus 2 times the material thickness, such as Figure 5 As shown, the tensile test specimen is stretched to the ultimate strain of 3.67% measured in step 3 and then the stretching is stopped. The ultimate strain ε at the outer bending radius of the sheet is 3.67%.

[0069] 5. Process the deformed area of ​​the tensile specimen in step 4 into a rectangular sheet. The direction of the extension line of the bending radius of the sheet is opposite to that in step 3, such as Figure 6As shown, according to the minimum inner bending radius determined in step 2, the punch radius is selected to be 20 mm, and the sheet metal is subjected to a bending test at the maximum bending angle of 100 degrees determined in step 2.

[0070] 6. If no cracks appear on the current sheet in the bending tests in step 3 and step 5, the current sheet can meet the manufacturing requirements of the bent part.

[0071] Based on the material bending deformation mechanism, this method correlates the material's bending deformation characteristics with the bending deformation characteristic parameters of the component, leveraging the microscopic deformation mechanism during the bending process to accurately predict the bending characteristics of the component. This method can scientifically and accurately predict bending cracks in sheet metal and tubular components, overcoming the technical difficulty of traditional empirical methods in determining high-strength materials. It significantly improves the accuracy of component bending deformation prediction and is highly suitable for determining components with multiple different bending characteristics, widely meeting the application requirements of practical engineering and scientific research.

[0072] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for determining the manufacturability of a plate bending pipe, characterized in that: The specific steps include: 1) Identify the cross-sectional features of the part and measure the minimum bending radius inside the cross-sectional area of ​​the part as R 截面内弯min , unit mm; the minimum bending radius outside the part section is R 截面外弯min , unit mm; the maximum bending angle of the part section is α 截面max , unit °; 2) Identify the overall contour of the part and measure the minimum bending radius of the inner side of the part's bend as R 整体内弯min , unit mm; the minimum bending radius of the outer side of the part is R 整体外弯min , unit mm; the maximum bending angle of the part is α 整体max , unit °; 3) If R 截面内弯min <R 整体内弯min , then the rectangular sheet is made in such a way that the rolling direction of the sheet is perpendicular to the center line of the bending radius; Punch radius and R 截面内弯min Adapt to the sheet metal 截面max °Bending test, the limit strain at the outer bending radius of the sheet is measured as ε; 4) Process the uniaxial tensile specimen in the direction of the rectangular sheet material in step 3). The width of the deformation area in the middle of the dumbbell-shaped uniaxial tensile specimen satisfies: L w ≥2.5×(R 整体内弯min +t); Where: L w is the width of the deformation area in the middle of the dumbbell-shaped uniaxial tensile specimen, mm; R 整体内弯min The minimum bending radius of the inner side of the part, mm; t is the thickness of the part, mm; The tensile test specimen is stretched to the ultimate strain measured in step 3) and then the stretching is stopped; 5) Process the deformed area of ​​the tensile specimen in step 4) into a rectangular sheet. The direction of the extension line of the bending radius of the sheet is opposite to that in step 3). The punch radius is the same as R 整体内弯min Adapt to the sheet metal 整体max °Bending test; 6) If cracks appear in the sheet during the bending test in step 3) or step 5), the current sheet cannot meet the use requirements and needs to be replaced with a material with better bending performance; If no cracks appear in the sheet material during the bending tests in step 3) and step 5), the current sheet material can meet the manufacturing requirements of the bent part.

2. The method for determining the manufacturability of a plate tube bend according to claim 1, characterized in that: In the step 1), the part is a bent tube with a rectangular cross section.

3. The method for determining the manufacturability of a plate tube bend according to claim 1, wherein: In step 3), if R 截面内弯min >R 整体内弯min , the rectangular sheet is made in such a way that the rolling direction of the sheet is parallel to the center line of the bending radius.

4. The method for determining the manufacturability of a plate tube bend according to claim 1, wherein: In the step 3), the sheet material is a metal sheet material.

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