Weld width design method, manufacturing method, manufacturing system, weld width design system, vehicle structural member, and tailor-welded member

Abstract

A width of a weld of a press-formed product obtained by press forming a tailor-welded blank is made close to a target width. A method for designing a weld width of a tailor-welded blank includes: a model acquisition step (S11) of acquiring analysis model data containing an element of a first sheet material, an element of a second sheet material, and an element of a weld; a press forming analysis step (S12) of calculating deformations of the elements in a case where the tailor-welded blank is press formed, by using a press forming analysis using the analysis model data; and a weld width design step (S14) of deciding design values of the width of the weld at respective positions in a longitudinal direction of the weld of the tailor-welded blank before press forming, based on changes in the width of the element of the weld due to the press forming, which are obtained by the calculation, and generating weld width design data indicating a relationship between the positions in the longitudinal direction of the weld and the design values of the width of the weld.

Description

Technical Field

[0001] This invention relates to a technique for designing and manufacturing tailored blank components. Background Technology

[0002] In recent years, welded components, formed by joining multiple plates through welding, have been used as stamping components. The joining of the welded plates is performed, for example, by laser welding or plasma welding. The joint obtained through welding is called a weld. Basically, to prioritize weld stability, welding is generally performed in a manner that ensures a constant weld width and constant strength characteristics.

[0003] As a method for controlling the heat input in laser welding, for example, Japanese Patent No. 3115733 discloses a method for controlling the heat input in laser seam welding that satisfies appearance quality and joint strength in laser seam welding using YAG lasers or the like. Additionally, Japanese Patent No. 6609974 discloses a laser welding apparatus for efficiently performing repair welding corresponding to the welding state of the welded area in the welding of fuel cell separators.

[0004] Furthermore, the location of the weld line, or weld seam, in welded components affects the quality of stamped products using these components. Therefore, a method for designing the weld line based on computer simulation results has been proposed. For example, Japanese Patent No. 4858259 discloses a method for setting the weld line in welded components using stamping analysis. In this method, during the stamping analysis, the defect-prone areas and defect-prone areas are calculated when the blank has been stamped, and the weld line is set to avoid these calculated defect-prone areas and defect-prone areas.

[0005] Japanese Patent No. 5119712 discloses a design method for welded components. In this method, for welded components formed into a molded product shape by stamping, the finite element method is used to set the joint lines. Specifically, a molded product shape model is obtained by stamping a virtual welded component model with virtual joint lines set thereon. For the molded product shape model, arbitrary deformation tests are performed using the finite element method, including flexure tests, torsion tests, and vibration tests, and the deformation amount of the molded product shape model is calculated. The virtual joint lines are modified in a manner that ensures the calculated deformation amount is within the elastic limit, thereby setting the joint lines.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent No. 3115733

[0009] Patent Document 2: Japanese Patent No. 6609974

[0010] Patent Document 3: Japanese Patent No. 4858259

[0011] Patent Document 4: Japanese Patent No. 5119712 Summary of the Invention

[0012] The problem the invention aims to solve

[0013] In tailor-welded blanks (also called welded plates), the position of the weld on the formed surface sometimes shifts and the weld width changes due to stamping. This is especially true in hot stamping, where high temperatures cause weld deformation. Previously, in the design of tailor-welded blanks, welds were generally omitted from calculations based on forming analysis and collision analysis. However, in actual cases where two plates of different strengths are joined by welding, the weld formed by the fusion of the ends of the plates sometimes represents approximately the middle strength of the two plates. Therefore, the weld strength is sometimes lower than that of the plate with the higher strength. In view of this situation, the inventors found it necessary to consider the weld in the analysis. Furthermore, the inventors noted that when the weld width increases or decreases due to forming, the ratio of high-strength to low-strength regions on the formed surface changes. Consequently, the final strength characteristics of the formed product may deviate from the results obtained through prior analysis. For example, if the weld strength is lower than the strength of the plate on the high-strength side, the high-strength region will decrease when the weld width increases due to stamping. In this case, the strength characteristics obtained through analysis without considering the weld may be overestimated.

[0014] Therefore, the inventors have studied the following: controlling the width of the weld in a stamped product manufactured by stamping welded components. This application discloses a weld width design method, manufacturing method, manufacturing system, weld width design system, program, vehicle structural component, and welded component that can take into account the changes in weld width caused by stamping of the welded component to make the weld width of the stamped product approach a target width.

[0015] Solution for solving the problem

[0016] A method for designing the weld width of a welded component according to one embodiment of the present invention includes: a model acquisition step, acquiring analysis model data, wherein the analysis model data represents data of a welded component having a first plate and a second plate joined together, the analysis model data including elements of the first plate, elements of the second plate, and elements of the weld between the ends of the first plate and the second plate; a stamping analysis step, using the analysis model data to perform a stamping analysis, thereby calculating the deformation of the elements of the first plate, the second plate, and the weld when the welded component has been stamped; and a weld width design step, based on the change in the width of the weld elements due to stamping obtained from the calculation results of the stamping analysis step, determining the design value of the weld width at each position in the long side direction of the weld of the welded component before stamping, and generating weld width design data representing the relationship between the position in the long side direction of the weld and the design value of the weld width.

[0017] The effects of the invention

[0018] According to this disclosure, it is possible to take into account the changes in the width of the weld seam of the welded component due to stamping to make the width of the weld seam of the stamped product close to the target width. Attached Figure Description

[0019] Figure 1 This is a functional block diagram illustrating a structural example of the design and manufacturing system for the welded components in this embodiment.

[0020] Figure 2 This is a flowchart illustrating an example of the actions of the designed system.

[0021] Figure 3 This is a diagram showing an example of a welded component model.

[0022] Figure 4 It shows the use Figure 3 The figure shows an example of the results obtained by performing stamping analysis on the welded component model shown.

[0023] Figure 5 It is shown Figure 3 and Figure 4 The graph shows the values ​​of the weld widths W1 and W2 in the welded component model shown.

[0024] Figure 6 This is a graph showing an example of the results of the second stamping analysis.

[0025] Figure 7 This is a graph showing the rate of change of weld width in the first and second stamping analyses.

[0026] Figure 8 This is a flowchart illustrating other action examples of the design system 1.

[0027] Figure 9 This is a diagram showing an example of a welded component model represented by analysis model data with joint lines.

[0028] Figure 10 It shows the use Figure 9 The figure shows a partial example of the results obtained from stamping analysis of the welded component model.

[0029] Figure 11 It is shown Figure 9 and Figure 10 A graph showing the width W01 values ​​of the elements on both sides of the joint line in the welded component model shown.

[0030] Figure 12 This is a flowchart illustrating an example of the operation of the control unit 23.

[0031] Figure 13 This is a diagram showing an example of a stamped article in this embodiment.

[0032] Figure 14 This is a diagram showing an example of a stamped article in this embodiment.

[0033] Figure 15 This is a diagram showing an example of a stamped article in this embodiment.

[0034] Figure 16 This is a diagram showing an example of a stamped article in this embodiment.

[0035] Figure 17 This is a diagram showing an example of a stamped article in this embodiment.

[0036] Figure 18 It is shown Figure 17 The diagram shows the welded components. Detailed Implementation

[0037] (Design Method 1)

[0038] A method for designing the weld width of a welded component according to one embodiment of the present invention includes: a model acquisition step, acquiring analysis model data, wherein the analysis model data represents data of a welded component having a first plate and a second plate joined together, the analysis model data including elements of the first plate, elements of the second plate, and elements of the weld between the ends of the first plate and the second plate; a stamping analysis step, using the analysis model data to perform a stamping analysis, thereby calculating the deformation of the elements of the first plate, the second plate, and the weld when the welded component has been stamped; and a weld width design step, based on the change in the width of the weld elements due to stamping obtained from the calculation results of the stamping analysis step, determining the design value of the weld width at each position in the long side direction of the weld of the welded component before stamping, and generating weld width design data representing the relationship between the position in the long side direction of the weld and the design value of the weld width.

[0039] In design method 1 described above, by performing stamping analysis using analysis model data containing weld elements, it is possible to analyze how the weld width changes due to stamping. Based on the changes in the width of the weld elements due to stamping obtained through analysis, a design value for the weld width before stamping is determined. The design value is determined for each position along the long side of the weld. Furthermore, weld width design data representing the relationship between the position along the long side of the weld and the design value of the weld width is generated. Thus, data representing the distribution of the design value of the weld width along the long side, taking into account the changes in the weld width due to stamping, is obtained. For example, based on the changes in the width of the weld elements due to stamping obtained through calculation, a design value for the weld width that makes the changed weld width close to the target value (target value) can be determined. Furthermore, the design value represents the weld width value that should be set when manufacturing welded components. The weld width design data shows how the weld width should be set at each position along the long side of the weld. In this way, by using the weld width design data, the changes in the weld caused by stamping can be taken into account, so that the weld after stamping is close to the target width.

[0040] The determination of the design value for the weld width may include, for example, the following process: using the width values ​​of the weld elements after stamping, obtained through calculations in the stamping analysis process, to determine the design value for the weld width at each position along the long side of the weld of the pre-stamped component. As an example, the design value for the weld width can be determined using the calculated width values ​​of the elements at each position along the long side of the weld after stamping, and the target position of the weld width after stamping.

[0041] In the weld width design process, for example, the design value for the weld width can be determined based on the change in the width of the weld element due to stamping, which is calculated by the process. This design value aims to make the changed weld width approximately uniform along the entire long side of the weld. In other words, the target value for the weld width after stamping can be set as a uniform width along the entire long side. Therefore, the weld width of the pre-stamped welded component can be determined in a way that ensures the weld width is uniform along the entire long side after stamping. Furthermore, the long side direction of the weld is the direction in which the weld extends.

[0042] (Design Method 2)

[0043] In the above design method 1, the model acquisition process, the stamping analysis process, and the weld width design process may be repeated more than twice. Alternatively, in the model acquisition process after the second time, analytical model data containing elements of the weld with a width based on the weld width design data generated through the previous weld width design process may be acquired. Due to the change in weld width, the stress and deformation balance of the surrounding elements changes. Therefore, the weld width of the stamped component of the welded member, based on the weld width design data obtained through one stamping analysis, may deviate from the target weld width. By repeatedly performing the analytical model data acquisition, stamping analysis, and weld width design processes using the weld width design data obtained from the previous calculation as described above, the weld after stamping can be made closer to the target value.

[0044] (Design Method 3)

[0045] The above design method 1 or 2 may also further include: a process for obtaining a model with a joint line, wherein the model with a joint line is data representing a welded component having a first plate and a second plate that are joined to each other, the model with a joint line having elements of the first plate and elements of the second plate, and including a joint line where the elements of the first plate and the elements of the second plate are joined as the joint line between the first plate and the second plate; a process for performing a stamping analysis, using the model with a joint line to perform a stamping analysis, thereby calculating the deformation of the elements of the first plate and the second plate when the welded component shown in the model with a joint line has been stamped; and an initial value generation process, based on the changes in the width of the elements of the first plate and the second plate on both sides of the joint line obtained from the calculation results of the process for performing the stamping analysis, determining the initial value of the width of the weld corresponding to the joint line, and generating initial value data representing the relationship between the position of the weld in the long side direction and the initial value of the weld width. Alternatively, in the model acquisition process, the analysis model data containing elements of the weld having a width based on the initial value data generated through the initial value generation process can be acquired.

[0046] In design method 3 described above, analysis model data with a weld line, using the boundary line between elements of the first and second plates as the weld joint line, is used to determine the initial value of the weld width based on the width variation of the elements connected to the weld line during stamping. Thus, the weld width, taking into account the width variation of the portion near the weld line due to stamping, is set as the initial value. Analysis model data containing elements with weld widths based on the initial value is used to calculate the deformation of the elements during stamping. The design value of the weld width is determined based on the calculated width variation of the weld elements. Therefore, weld width design data that more easily makes the weld width after stamping approach the target value can be obtained.

[0047] (Manufacturing Method 1)

[0048] A method for manufacturing a welded component according to one embodiment of the present invention includes the following steps: obtaining weld width design data indicating the relationship between the position of the weld seam in the long side direction and the width of the weld seam; and a welding step in which the ends of a first plate and a second plate are joined together, and the molten portion travels along the joining line, thereby welding the ends of the first plate and the second plate together. In the welding step, the molten portion is traveled while controlling the amount of heat input for melting based on the weld width design data.

[0049] According to the manufacturing method 1 described above, welding is performed by controlling the heat input while the molten portion travels along the butt joint, based on pre-acquired weld width design data that represents the relationship between the position of the weld in the long side direction and the width of the weld. The heat input at each molten position is controlled based on the weld width design data. For example, the heat input can be changed according to the molten position, i.e., the position in the long side direction of the butt joint, based on the weld width design data. Thus, the relationship between the position of the weld in the long side direction and the width of the weld, as represented by the weld width design data, can be reflected in the actual weld width. That is, the variation in the width of the weld in the long side direction of the manufactured welded component is controlled by the weld width design data. By controlling the weld width in this way, the weld width of the stamped product obtained by stamping the welded component can be made close to the target width.

[0050] In manufacturing method 1 described above, the weld width design data can also be weld width design data generated by any of the design methods 1 to 3 described above. This allows for a more reliable approximation of the target weld width.

[0051] (Manufacturing Method 2)

[0052] In manufacturing method 1 described above, the molten portion can also be advanced during the welding process while controlling the filler supply based on the weld width design data. This allows the filler supply to be adjusted according to the weld width. For example, when the weld width is wide, the molten metal of the first and second plates can easily separate due to surface tension, resulting in welding defects. For example, by increasing the filler supply when the weld width increases, such welding defects can be made less likely to occur. That is, the weld can be stably controlled. As a result, the weld width can be more reliably made to approach the target width.

[0053] (Manufacturing System)

[0054] A manufacturing system for welded components according to one embodiment of the present invention includes: a heat input device that inputs heat to the ends of a first plate and a second plate that are joined together to melt the ends of the first plate and the second plate; a moving device that moves the position where heat is input by the heat input device along the joint line between the ends of the first plate and the second plate; and a control unit that controls the heat input device and the moving device. The control unit acquires weld width design data representing the relationship between the position of the weld seam in the long side direction of the weld of the welded component and the width of the weld seam, and controls the amount of heat input for melting by the heat input device and the movement of the heat input position by the moving device based on the weld width design data.

[0055] (Design System)

[0056] Furthermore, each step in the design methods 1 to 3 described above is executed by a computer. A system for processing any one of the design methods 1 to 3 described above is also included in the embodiments of the present invention. A weld width design system for a welded component according to one embodiment of the present invention comprises: a model acquisition unit that acquires analysis model data, wherein the analysis model data represents data of a welded component having a first plate and a second plate joined together, the analysis model data including elements of the first plate, elements of the second plate, and elements of the weld between the ends of the first plate and the second plate; a stamping analysis unit that uses the analysis model data to perform stamping analysis, thereby calculating the deformation of the elements of the first plate, the second plate, and the weld when the welded component has been stamped; and a weld width design unit that, based on the change in the width of the weld elements due to stamping obtained from the calculation results of the stamping analysis unit, determines the design value of the weld width at each position in the long side direction of the weld of the welded component before stamping, and generates weld width design data representing the relationship between the position in the long side direction of the weld and the design value of the weld width.

[0057] (program)

[0058] Furthermore, a program that enables a computer to execute any one of the design methods 1 to 3 described above, and a recording medium containing such a program, are also included in embodiments of the present invention. In one embodiment of the present invention, the program enables a computer to perform the following processes: model acquisition processing, acquiring analysis model data, wherein the analysis model data represents data of a welded component having a first plate and a second plate joined together, the analysis model data including elements of the first plate, elements of the second plate, and elements of the weld between the ends of the first plate and the second plate; stamping analysis processing, using the analysis model data to perform stamping analysis, thereby calculating the deformation of the elements of the first plate, the second plate, and the weld when the welded component has been stamped; and weld width design processing, based on the change in the width of the weld elements due to stamping, obtained from the calculation results of the stamping analysis processing, determining the design value of the weld width at each position along the long side of the weld of the welded component before stamping, and generating weld width design data representing the relationship between the position along the long side of the weld and the design value of the weld width.

[0059] (Structural components for vehicles)

[0060] In one embodiment of the present invention, a vehicle structural member is formed from a stamped article using a welded component, the welded component having a first sheet and a second sheet joined together, and a weld seam welding the ends of the first sheet and the ends of the second sheet together. The stamped article includes at least one of a portion that has undergone tensile flange deformation, a portion that has undergone shrinkage flange deformation, and a portion that has undergone protrusion deformation during stamping. The width of the weld seam in the portion that has undergone tensile flange deformation, the portion that has undergone shrinkage flange deformation, or the portion that has undergone protrusion deformation is equal to the width of the weld seam in the other portions.

[0061] In many cases, vehicle structural components that are stamped products include at least one of the following: portions that have undergone tensile flange deformation, portions that have undergone shrinkage flange deformation, and portions that have undergone protrusion deformation during stamping. That is, in stamped products of vehicle structural components, different deformation portions coexist. In this case, for example, it is possible to make the distribution of the width of a single weld in the longitudinal direction of the pre-forming welded component equal to the distribution of weld widths after stamping. In this structure, by making the weld widths of different deformation portions equal, the influence of weld width deviations on the strength characteristics of the vehicle structural component is reduced. For example, it is possible to distribute the individual materials of the welded plate component to the designed areas. Therefore, the difference between the crash performance predicted by CAE or the like and the actual performance of the stamped product is reduced. Furthermore, even if a single weld is provided in the portion where tensile flange deformation, shrinkage flange deformation, or protrusion deformation occurs, the influence of weld width variations on the performance of the stamped product can be suppressed. Therefore, the design limitations on the weld position are reduced. As a result, the design freedom of the welding line, i.e., the weld seam, can be increased, and the performance of the stamped product can be ensured. Furthermore, the vehicle structural component can also be a stamped product manufactured by manufacturing method 1 or 2 described above. The vehicle structural component can also be a hot-pressed product. A stamped product using welded components is a stamped product composed of welded components.

[0062] The equality of weld width includes not only cases where the width is strictly the same, but also cases where there are slight differences to the extent that they can be considered to be the same in terms of strength characteristics. In a single weld of the stamped article, if the width of the weld in the portion where tensile flange deformation, shrinkage flange deformation, or protrusion deformation has occurred is within ±13% of the width of the weld in other portions that have not undergone any of these deformations or have experienced relatively small deformations during stamping, these widths are considered equal. If the ratio of the minimum to the maximum width of a single weld along its entire long side in the stamped article is 77% ≤ minimum / maximum ≤ 100%, the aforementioned weld widths are also considered equal, and the width is uniform along the entire long side of the weld. Furthermore, in a single weld of the stamped article, the ratio of the width of the weld in the portion where tensile flange deformation, shrinkage flange deformation, or protrusion deformation has occurred to the width of the weld in the other portions is preferably within ±8%, more preferably within ±5%. The ratio of the minimum to the maximum width of a weld seam along the entire long side of the stamped product is preferably 85% ≤ minimum / maximum ≤ 100%, more preferably 90% ≤ minimum / maximum ≤ 100%.

[0063] As an example, the vehicle structural member may also include: a roof plate; a pair of longitudinal walls extending from both ends of the roof plate and facing each other; and a pair of flanges extending from the ends of the pair of longitudinal walls opposite to the roof plate in a direction away from each other outwards. The ridge line between the flanges and the longitudinal walls may also include a bend that curves when viewed from a direction perpendicular to the surface of the flange. Alternatively, the weld may be formed such that the width of the weld at the portion of the flange extending outwards from the bend is equal to the width of the weld at other portions (e.g., the longitudinal walls or the roof plate). In other words, the weld may be formed such that the width of the weld at the portion of the flange extending from the bend in a direction opposite to the flow of material during stamping is equal to the width of the weld at other portions (e.g., the longitudinal walls or the roof plate). In this case, in the vehicle structural member, the width of the weld at the portion where tensile flange deformation or shrinkage flange deformation occurs is equal to the width of the weld at other portions.

[0064] As an example, the curved portion of the ridge may also include a portion that curves outward in a direction extending from the ridge toward the flange, i.e., in a direction perpendicular to the surface of the flange (an outwardly curved portion). By making the width of the weld at the portion of the flange extending outward from this outwardly curved portion equal to the width of the weld at other portions, the width of the weld at the portion where the flange deformation has occurred is equal to the width of the weld at other portions.

[0065] The curved portion of the ridge may also include a portion that curves inward from the ridge in a direction opposite to the direction in which the flange extends, i.e., in a direction perpendicular to the surface of the flange (an inwardly curved portion). By making the width of the weld at the portion of the flange extending outward from this inwardly curved portion equal to the width of the weld at other portions, the width of the weld at the portion where the flange deformation has occurred is equal to the width of the weld at other portions.

[0066] (Welded components)

[0067] In one embodiment of the present invention, the welded component includes a first plate and a second plate joined together, and a weld seam that welds the end (side) of the first plate to the end (side) of the second plate. The weld seam includes a portion whose width is 80% to 91% of the maximum width of the weld seam.

[0068] By providing a portion with a width of 80% to 91% of the maximum width for one weld in a welded component, the width of this weld portion can be made nearly equal to the width of the welds in other portions in a stamped product obtained by stamping the welded component. For example, by making the width of the portion of the weld that will undergo tensile strain (tension) in the width direction due to deformation of the tensile flange 80% to 91% of the maximum width, the width of this portion can be nearly equal to the width of other portions after forming. Alternatively, by including the portion of the weld that will undergo compressive strain (shrinkage) in the width direction due to deformation of the shrinkage flange in the maximum width portion, and making the width of other portions that do not shrink or have relatively small shrinkage 80% to 91% of the maximum width, the width of the shrinkage portion can be nearly equal to the width of other portions after forming.

[0069] The inventors discovered that in the deformation of a stretch flange, shrink flange, or protrusion during stamping, the rate of change of the weld width relative to its width before forming can be assumed to be approximately 10% to 25%. Therefore, for example, by making the width of the portion of the weld that undergoes greater deformation than other portions during stamping before forming 80% to 91% of the width of the other portions, the width of the portion of the weld that has undergone greater deformation after forming can be made approximately equal to the width of the other portions. That is, the ratio of the width of the portion of the weld that has undergone greater deformation after forming to the width of the other portions can be made approximately within ±13%. From the same viewpoint, it is preferable that the weld before forming includes a portion with a width of 87% to 91% of its maximum width. In this case, as long as the rate of change of the weld width relative to its width before forming during the deformation of a stretch flange, shrink flange, or protrusion is in the range of 10% to 15%, the ratio of the width of the portion of the weld that has undergone greater deformation after forming to the width of the other portions can be made approximately within ±5%.

[0070] Furthermore, the maximum width of a single weld is the width of the portion with the greatest width along the entire long side of the weld. In this welded component, the weld width varies depending on its position along the long side. In this structure, a single weld may also include a portion with a constant width that does not change along the long side. For example, a portion where the weld width is the maximum width may be continuously formed along the long side. Alternatively, the width of a single weld may be 80% or more of the maximum width along the entire long side of the weld. That is, a single weld may also be formed without including portions with a width less than 80% of the maximum width. Furthermore, it is preferable that the width of a single weld is 87% or more of the maximum width along the entire long side of the weld.

[0071] In the welded component, the weld may extend from one end of the welded component to the other. Alternatively, a portion with a width of 80% to 91% of the maximum width may be provided at at least one end of the weld that includes the first end and the other end that includes the second end. Thus, for example, when forming the welded component in a manner that causes tensile flange deformation at the end, the portion of the weld end that undergoes tensile flange deformation can be the portion with a width of 80% to 91% of the maximum width. In this case, the width of the portion is stretched during forming. As a result, the width of the formed portion becomes equal to the width of other portions that do not undergo tensile flange deformation. Furthermore, one end of the weld is a portion in the long side direction of the weld and includes that end, while the other end of the weld is a portion in the long side direction of the weld and includes that other end. Alternatively, at least one of the following ranges may include a portion whose width is 80% to 91% of the maximum width, within a range of 20cm to 40cm along the long side of the weld from one end and from the other end. Furthermore, the weld may have portions with a width of 80% to 91% of the maximum width at both the one end and the other end. Thus, for example, when the weld is formed in a manner that causes tensile flange deformation at both ends, the weld width at the two ends where tensile flange deformation occurs can be made approximately equal to the weld width of the other portions.

[0072] In the welded components, the weld width in areas where tensile flange deformation, shrinkage flange deformation, or protrusion deformation is predicted to occur during stamping may differ from the weld width in other areas where such deformation is predicted to be absent or minimal. That is, the weld width of the blank before stamping may vary along its long side based on the predicted deformation caused by stamping. Thus, in the stamped product, the weld width in the portions where tensile flange deformation, shrinkage flange deformation, or protrusion deformation occurs can be made approximately equal to the weld width in other portions. For example, in the welded components, the weld width in areas where tensile flange deformation is anticipated during stamping may be smaller than the weld width in other areas where tensile flange deformation is anticipated to be absent or minimal. Furthermore, for example, the areas where tensile flange deformation, shrinkage flange deformation, or protrusion deformation is predicted to occur during stamping can be determined based on the design information of the stamped product. Alternatively, this area can be determined through computer analysis (e.g., CAE) based on the design data of the stamped product.

[0073] Furthermore, a method for manufacturing the vehicle structural member is also included in an embodiment of the present invention. The manufacturing method includes the following steps: joining a first sheet metal and a second sheet metal by welding to form a welded member; and stamping the welded member. In the stamping process, at least one of tensile flange deformation, shrinkage flange deformation, and protrusion deformation is applied to a portion of the welded member. In the step of forming the welded member, the welding is performed in such a way that the width of the weld in the region where the tensile flange deformation, shrinkage flange deformation, or protrusion deformation is predicted to occur is different from the weld width in other regions where these deformations are predicted not to occur or are relatively small. Thus, it is possible to manufacture the vehicle structural member in which the width of the weld in the portion where tensile flange deformation, shrinkage flange deformation, or protrusion deformation has occurred is equal to the width of the weld in other portions. Furthermore, in the step of forming the welded member, it is also possible to form a welded member in which the weld width includes a portion whose width is 80% to 91% of the maximum width of the weld. The stamping process may also be, for example, hot pressing.

[0074] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Identical or equivalent parts in the drawings are labeled with the same reference numerals, and their descriptions will not be repeated. The dimensional ratios between structural components shown in the figures do not necessarily represent actual dimensional ratios.

[0075] [System Structure Example]

[0076] Figure 1 This is a functional block diagram illustrating a structural example of the weld width design system 1 (hereinafter, sometimes simply referred to as "Design System 1") and the manufacturing system 2 for the welded component in this embodiment. Design System 1 generates weld width design data using the results of stamping analysis based on analytical model data, which is obtained by modeling the welded component using multiple elements. The weld width design data represents the relationship between the position of the weld along its long side and the width of the weld. Manufacturing System 2 manufactures the welded component by controlling the welding position and heat input along the butt joint lines of multiple plates based on the weld width design data.

[0077] (Example of system structure design)

[0078] The design system 1 includes a model acquisition unit 11, a stamping analysis unit 12, and a weld width design unit 13. The model acquisition unit 11 acquires analysis model data representing the welded components. The model acquisition unit 11 reads the analysis model data from a recording device accessible to the design system 1, so that the analysis model data can be used in the stamping analysis unit 12.

[0079] The analysis model data acquired by the model acquisition unit 11 is obtained by modeling the welded component, which is a stamping object component before stamping, using multiple elements. The stamping object component can be a flat plate or an intermediate formed product. The multiple elements representing the welded component can be, for example, shell elements, solid elements, or combinations thereof. In addition to acquiring the analysis model data, the model acquisition unit 11 can also acquire mold data representing the shape of the mold in the stamping of the analysis object.

[0080] The analysis model data is not particularly limited, but it can be generated from shape data representing the shape of the welded component, such as CAD data. For example, the data obtained by segmenting (mesh segmentation) the welded component represented by the shape data can be used as the analysis model data. The design system 1 may also have a function to generate analysis model data based on shape data. In this case, the design system can automatically perform the segmentation process of the welded component represented by the shape data. In addition, in the segmentation process, the user can receive input regarding at least one of the following: the type of element, the number of elements, or the joint position of the elements.

[0081] The analysis model data includes elements of the first plate (first plate model), elements of the second plate (second plate model), and elements of the weld between the ends of the first and second plates (weld model). The analysis model data is obtained by modeling the welded component obtained by joining the ends (sides) of the first and second plates together through welding. In the analysis model data, the weld elements are positioned between the elements of the first and second plates. For example, the weld can be modeled using multiple elements arranged along its long side. The width of the weld elements corresponds to the width of the weld. The weld width can be set as the size of the weld in a direction perpendicular to the long side (extension direction) of the weld, viewed from a direction perpendicular to the surface of the welded component. In the analysis model data, the width of the weld elements can be set to be constant along the long side of the weld or to vary along the long side of the weld.

[0082] The stamping analysis unit 12 calculates the deformation of each element when the welded component is stamped into a stamped product using simulation (stamping analysis) performed by using analysis model data. The stamping analysis unit 12 performs, for example, a stamping analysis process based on the finite element method. In the stamping analysis process, firstly, the analysis model data and die data representing the die shape are determined. For example, the analysis model data and die data acquired by the model acquisition unit 11 are used in the stamping analysis process. In the stamping analysis process, boundary conditions and material property values ​​are determined. These boundary conditions and material property values ​​can be pre-included in the analysis model data and / or die data, determined based on user input, or determined based on pre-recorded data.

[0083] For example, material property values ​​can be set separately for the first plate, the second plate, and the weld. Examples of material property values ​​include stress-deformation characteristics, Young's modulus, density, thermal conductivity, and specific heat, but are not limited to these.

[0084] Examples of boundary conditions include, but are not limited to, the coefficient of friction, the coefficient of heat transfer, constraints on the displacement of elements, and the stroke of the mold. For example, constraints on the displacement of elements could also include positional limitations on the weldment plate. Specific examples of constraints could include fixing an element of a portion of the weldment plate (e.g., the center or end) to a designated point to prevent its movement.

[0085] The stamping analysis unit 12 uses analysis model data, die data, boundary conditions, and material property values ​​to perform prescribed calculations, thereby calculating the stress and deformation of each element in the stamping process. In the calculation of stress and deformation, the effects of factors such as temperature can also be considered. That is, the stamping analysis performed by the stamping analysis unit 12 can also include thermal conductivity and thermal deformation analysis of welded components in the stamping process.

[0086] The stamping analysis unit 12 can output data showing how the welded component deforms due to stamping as analysis results. The shape of the welded component after stamping, i.e., the stamped product, is represented by the elements after stamping calculated through stamping analysis. For example, the analysis results of the stamping analysis unit 12 may also include data representing the width of the weld after stamping or the amount of change caused by stamping. Furthermore, the analysis results of the stamping analysis unit 12 may include not only the deformation of elements but also internal stress, temperature, and other physical quantities.

[0087] The weld width design unit 13 uses the analysis results from the stamping analysis unit 12 to determine the design value of the weld width of the welded component before stamping. Here, the design value for each position along the long side of the weld is determined. The weld width design unit 13 generates weld width design data. The weld width design data is data representing the relationship between the position of the weld along the long side and the design value of the weld width. The weld width design data is data representing the distribution of the width along the long side of the weld. The weld width design data is not limited to representing the weld width when it is constant; it can also represent the weld width when the weld width changes along the long side. That is, the weld width design data can be used to represent the design values ​​of different weld widths along the long side. The design value of the weld width represented by the weld width design data is not limited to the value of the weld width (dimension); for example, it can also be the rate of change of width along the long side or other values ​​related to the weld width. The weld width design data can, for example, be used as welding control parameters when welding a first plate and a second plate together in the manufacturing system 2 to manufacture a welded component. Therefore, it is possible to make the welds conform to the design in the manufactured welded components.

[0088] The weld width design unit 13 can determine a design value for the weld width that approximates the target value, based on the change in the width of the weld element caused by stamping, calculated by the stamping analysis unit 12. For example, the weld width design unit 13 can also calculate the difference between the width of the stamped weld after stamping, as indicated by the analysis results of the stamping analysis unit 12, and the target value, and determine the design value for the weld width based on this value. For example, the weld width of the pre-formed welded component can be changed to reduce the aforementioned difference. The changed weld width is then determined as the design value. As an example, the value obtained by applying a change opposite to the change in weld width calculated through analysis to the target value of the weld width after stamping can be determined as the design value for the width of the weld before stamping. In this way, the weld width design unit 13 can determine the design value based on the comparison result between the width of the stamped weld after stamping obtained through analysis and the target value. The target value can be pre-recorded or input by the user.

[0089] Design system 1 can also repeat the stamping analysis of stamping analysis unit 12 and the generation of weld width design data of weld width design unit 13 more than twice. In this case, stamping analysis unit 12 can use analysis model data that is set based on the weld width design data previously generated by weld width design unit 13 to perform stamping processing for the second time and thereafter. In this way, in design system 1, the width of the weld element in the analysis model data acquired by model acquisition unit 11 can be set based on the weld width design data previously generated by weld width design unit 13.

[0090] Alternatively, the initial value of the width of the weld element in the analysis model data used in the first stamping analysis of the stamping analysis unit 12 can be set based on the results of a preliminary stamping analysis using analysis model data with joint lines. That is, the stamping analysis unit 12 can also calculate the changes in the elements of the welded component caused by stamping by using simulation with analysis model data with joint lines, and determine the initial value of the weld width based on the calculation results.

[0091] The analysis model data with weld lines is acquired by the model acquisition unit 11. The analysis model data with weld lines includes elements of a first plate and elements of a second plate. The analysis model data with weld lines includes weld lines connecting elements of the first plate and elements of the second plate. That is, the weld lines between elements of the first plate and elements of the second plate that are connected thereto form welded weld lines. The weld line is, for example, the boundary line between the first plate and the second plate. There are no elements between elements of the first plate and elements of the second plate into which weld seams are inserted. The analysis model data with weld lines is not particularly limited, but for example, it is possible to generate the analysis model data based on the shape data of the welded components, similar to the analysis model data.

[0092] The stamping analysis unit 12 calculates the deformation of each element when the welded component represented by the joint line analysis model data is stamped using simulation (stamping analysis) with joint line analysis model data. The stamping analysis unit 12 performs, for example, a stamping analysis using the finite element method. As part of the analysis, the stamping analysis unit 12 calculates the change in the width of the elements on both sides of the joint line of the stamped part relative to the width of the elements on both sides of the joint line before stamping. Furthermore, the position of the joint line in the joint line analysis model data corresponds to the possible location of the weld. That is, the position of the joint line corresponds to the position of the weld.

[0093] The weld width design unit 13 can generate initial value data for the width of weld elements using the results of stamping analysis based on the data from the joint line analysis model. The weld width design unit 13 determines the initial value of the weld width of the welded component based on the changes in the width of the elements on both sides of the joint line due to stamping. It determines the initial value of the weld at the position corresponding to the joint line. Initial values ​​are determined for each position along the long side of the joint line. For example, based on the changes in the width of the elements on both sides of the joint line due to stamping, calculated by the stamping analysis unit 12, a value based on the width of the elements, such that the width of the changed elements is close to the target value, can be determined as the initial value of the weld element width. Alternatively, the initial value can be calculated based on a comparison between the width of the elements on both sides of the joint line after stamping and the target value. In this case, the target value can be either pre-recorded or input by the user. The weld width design unit 13 generates initial value data. The generated initial value data represents the relationship between the position of the weld along the long side and the initial value of the weld width. The width of the weld elements in the analysis model data is set based on this initial value data. The analysis model data is acquired by the model acquisition unit 11 and used in the stamping analysis of the stamping analysis unit 12.

[0094] Design system 1 can be configured as a computer with a processor and memory. By executing a program stored in memory, the functions of model acquisition unit 11, stamping analysis unit 12, and weld width design unit 13 can be realized. Such a program and a non-transitory recording medium containing the program are also included in embodiments of the present invention. Furthermore, each part of design system 1 can be implemented by multiple processors.

[0095] Furthermore, the structure of design system 1 is not limited to the examples described above. For instance, the design system may generate design values ​​or initial values ​​for the weld position in addition to generating weld width design data. For example, in the design system, the position of the weld in the welded component before stamping may be determined using the analysis results of the stamping analysis unit 12.

[0096] (Example of a manufacturing system structure)

[0097] Manufacturing system 2 includes a heat input device 21, a moving device 22, and a control unit 23. The heat input device 21 inputs heat to the ends of the first plate P1 and the second plate P2 that are joined together, melting these ends. The moving device 22 moves the position where heat is input by the heat input device 21 along the joint line between the ends of the first plate P1 and the second plate P2, i.e., along the long side of the joint portion. The control unit 23 controls the heat input device 21 and the moving device 22. The control unit 23 controls the amount of heat input for melting by the heat input device 21 and the movement of the heat input position by the moving device 22 based on weld width design data. The weld width design data represents the relationship between the position of the weld along the long side of the weld of the welded component and the width of the weld. The weld width design data is generated by design system 1.

[0098] The heat input device 21 is, for example, a laser welding apparatus. The laser welding apparatus includes a laser source and a focusing device that converges the laser beam. The beam focused by the focusing device becomes the heat input position. The moving device 22 changes the relative position of the heat input position of the heat input device 21 with respect to the components to be welded (in this example, the first plate P1 and the second plate P2). The moving device 22 may also include, for example, an actuator (e.g., a motor) that moves at least one of the support member supporting the heat input device 21 and the support member supporting the components to be welded. Furthermore, the heat input device 21 is not limited to a laser welding apparatus. The heat input device 21 may also be, for example, a plasma welding apparatus, a TIG welding apparatus, or other welding apparatus.

[0099] exist Figure 1 In the example shown, manufacturing system 2 includes a filler supply device 24. The filler supply device 24 supplies filler (welding filler material) to the heat input position. The filler supply device 24 is configured, for example, to hold the filler wire in a slidable manner and deliver the front end of the filler wire to the heat input position. The filler supply device 24 can also be controlled by a control unit 23. Furthermore, the filler supply device 24 can be omitted in manufacturing system 2. Additionally, the filler supply device 24 can also be part of the heat input device.

[0100] The control unit 23 can be configured as a computer or circuit having a processor and memory. For example, the control unit 23 can be configured as a computer or circuit built into at least one of the heat input device 21 or the mobile device 22, or it can be configured as a general-purpose computer.

[0101] The control unit 23 controls the heat input device 21 and the moving device 22 to control the heat input amount while moving the molten section along the butt joint line between the ends of the first plate P1 and the second plate P2. That is, the control unit 23 controls the heat input position and amount on the butt joint line by controlling the heat input device 21 and the moving device 22. The control unit 23 can change the heat input amount based on the heat input position. The heat input position and amount are controlled based on weld width design data. Weld width design data represents the relationship between the position of the weld along its long side and the width of the weld. The width of the weld is mainly determined by the heat input amount. For example, when the heat input amount increases, the weld width also increases. Therefore, the weld width design data can be said to represent the data indicating which position in the butt joint line should be set with what level of heat input. The control unit 23 can control the amount of heat input at each heat input position in the welding travel direction (that is, along the direction of the weld line) based on the width of the weld corresponding to the position in the long side direction of the weld as expressed by the weld width design data.

[0102] The control unit 23 can control the amount of heat input, for example, by controlling at least one of the laser output, welding speed, and focusing position (focusing position) of the heat input device 21. Furthermore, the welding speed is the speed at which the heat input position (molten part) travels in the direction of the weld line. The focusing position is the position of the focal point of the laser beam in the incident direction. The controlled amount of heat input is, for example, the energy density supplied for welding. Here, energy density refers to the amount of energy supplied to a unit area of ​​the component to be welded per unit time.

[0103] Furthermore, the control unit 23 can control not only the heat input position and heat input amount, but also the filler supply amount at the heat input position. That is, the control unit 23 can control the filler supply device 24 in addition to controlling the heat input device 21 and the moving device 22. Thus, the control unit 23 can control the filler supply amount. For example, the controlled filler supply amount can be set to the filler supply amount supplied to a unit area per unit time. The control unit 23 controls the filler supply position and supply amount. For example, the filler supply amount at the heat input position on the butt joint can be controlled based on weld width design data. Therefore, the filler supply amount changes accordingly with the weld width design value. For example, for a portion where the weld width is set wider than other portions according to the weld width design data, the filler supply amount can be greater than for other portions. In this case, by increasing the filler supply amount, the insufficient molten metal used to maintain a stable weld width can be compensated for. In this way, the control unit 23 can control the amount of filler supplied to the heat input position in the welding travel direction based on the width of the weld corresponding to the position in the long side direction of the weld as indicated by the weld width design data.

[0104] (Example 1 of the system design action)

[0105] Figure 2 This is a flowchart illustrating an example of the actions in design system 1. Figure 2 In the example shown, the model acquisition unit 11 acquires the analysis model data (S11). Figure 3 This is a diagram illustrating an example of a welded component model represented by analytical model data. Figure 3 The welded component model shown includes element EP1 of the first plate, element EP2 of the second plate, and element EB of the weld. The weld element EB is positioned between element EP1 of the first plate and element EP2 of the second plate. Furthermore, in Figure 3 In the diagram, the grid is omitted from the elements EP1 of the first plate and EP2 of the second plate. Figure 3 The model shown is a model of a welded component with holes penetrating the plate, and is a model of a quarter section of the welded component.

[0106] In the analysis model data, the width W1 of the weld element EB is set. Figure 3 In the example shown, the width W1 is uniform along the long side direction D of the weld, but the width W1 can also be set to be different along the long side direction D.

[0107] exist Figure 2 In step S12, the stamping analysis unit 12 uses the analysis model data obtained in step S11 to perform a stamping analysis (simulation). In the stamping analysis, the deformation of elements is calculated when the welded component has been stamped. The stamping analysis may also include heat treatment analysis. In this case, in addition to calculating the stress and deformation of elements when the welded component has been hot-pressed, temperature changes are also calculated.

[0108] Figure 4 It shows the use Figure 3 The figure shows an example of the results obtained by performing stamping analysis on the welded component model shown. Figure 4 The example shown is a case where a cylindrical cavity was formed in the case of a welded component made of flat plates. Figure 4 The grid diagram of the elements is omitted. Data representing the shape of the welded component after stamping is obtained through stamping analysis. Based on the width W2 of the weld element EB in the data of the welded component after stamping, information representing the change in weld width due to stamping is obtained.

[0109] Figure 5 It is shown Figure 3 and Figure 4 The graph shows the curves of the weld widths W1 and W2 in the welded component model shown. Figure 5In the curve diagram, the horizontal axis represents the distance from the inner circumference end A0 along the long side D of the weld, and the vertical axis represents the width of the weld. Figure 5 In the example shown, the weld width W1 before stamping is uniform along the long side D. The weld width W2 after stamping, obtained through analysis, is not uniform along the long side D and differs from the width W1 before stamping. The relationship between the weld's position and width along the long side D changes due to stamping. For example... Figure 5 As shown, the relationship between the position of the weld along the long side D and its width W2 illustrates the change in weld width due to stamping. The change in weld width can be calculated through stamping analysis in this way. Figure 5 T1 represents an example of the target value (target value) for the width of the weld after stamping.

[0110] exist Figure 2 In step S13, the weld width design unit 13 determines whether the weld width obtained through analysis after stamping meets the specified conditions. This determination can be based on a comparison between the weld width W2 obtained through analysis after stamping and the target value T1. For example, if the weld width W2 after stamping is within the specified range relative to the target value T1, it can be determined that the conditions are met.

[0111] If "Yes" is selected in S13, the weld width design unit 13 determines the width of the weld element before stamping as the design value (S15). In this case, for example, the data representing the relationship between the width W1 of the weld element EB in the analysis model data before stamping obtained by S11 and its position in the long side direction D is determined as the weld width design data.

[0112] If "No" is selected in S13, the weld width design unit 13 determines the design value of the weld width based on the weld width W2 after stamping and the target value T1 obtained through analysis (S14). Data representing the relationship between the design value of the weld width and its position in the long side direction D is generated as weld width design data. For example, the design value can be set as the value obtained by correcting the weld width W1 before stamping based on a value representing the difference between the weld width W2 after stamping and the target value T1 (e.g., difference or ratio). Figure 5 The example shown is the design value W3 calculated based on W1, W2, and T1.

[0113] The design value W3 at one position along the long side D can also be calculated based on the difference between the width W2 and the target value T1 (W2-T1), for example using the formula W3 = W1 - (W2-T1). Alternatively, the design value W3 can also be calculated based on the ratio of the width W2 to the target value T1 (W2 / T1), for example using the formula W3 = W1 × (T1 / W2).

[0114] The weld width design unit 13 sets the width of the weld element EB in the pre-forming analysis model data based on the weld width design data generated in S14. For example, the design value of the weld width determined in S14 can be set as the value of the width of the weld element EB in the analysis model data. The model acquisition unit 11 acquires analysis model data with the width of the element EB set based on the weld width design data (S11). Then, the acquired analysis model data is used to perform stamping analysis (S12).

[0115] Thus, processes S11 to S14 are repeated until it is determined that the weld width meets the specified condition ("Yes" in S13). Therefore, even if the weld width deviates from the target value due to strength characteristics, multiple forming analyses can be performed to bring the weld width variation closer to the target value T1. As a result, weld width design data is determined, containing a design value that makes the weld width after stamping close to the target value T1.

[0116] Figure 6 This is a graph illustrating an example of the results of the second stamping analysis. In the second stamping analysis, it is possible to use the analysis model data where the design value W3 of the weld width design data is set as the width of the weld element EB. Figure 6 The width W4 of element EB of the weld after stamping is shown as the result of the first analysis. Figure 5 The width W2 is closer to the target value T1.

[0117] Figure 7 This is a graph showing the rate of change of weld width (W2 / W1) in the first stamping analysis and the rate of change of weld width (W4 / W3) in the second stamping analysis. By updating the weld width in the welded component based on the generated design values ​​in this way, the difference between the weld width after stamping and the target value can be brought to converge.

[0118] (Example 2 of designing a system)

[0119] Figure 8 This is a flowchart illustrating other action examples of design system 1. In Figure 8 In the example shown, the model acquisition unit 11 acquires the analysis model data with the bonding line (S01). Figure 9This is a diagram showing an example of a welded component model represented by analysis model data with joint lines. Figure 9 The welded component model shown includes elements EP1 of a first plate and elements EP2 of a second plate that are connected to each other. The boundary line between elements EP1 of the first plate and elements EP2 of the second plate forms the weld joint line. That is, the analysis model data with the weld joint line includes the weld joint line defined by the boundary line between elements EP1 of the first plate and elements EP2 of the second plate that are connected to each other. In this example, the width (W01) of elements EP1 of the first plate and elements EP2 of the second plate that are connected to each other, i.e., the width (W01) of the elements on both sides of the weld joint line, corresponds to the width of the weld. As an example, let... Figure 9 The overall structure of element EP1 of the first plate and element EP2 of the second plate shown is similar to... Figure 3 Same. Additionally, let's assume... Figure 9 In the example shown, the direction of the long side of the joining line is the same as... Figure 3 The long side direction D of the weld shown is the same.

[0120] In the analysis model data with a joint line, set the width W01 of the elements on both sides of the joint line. Figure 9 In the example shown, the width W01 is uniform along the long side of the joint line, but the width W01 can also be set to vary along the long side of the joint line. Figure 9 In the example, the width W01 of the elements on both sides of the joint line is the sum of the widths of the elements on both sides of the joint line. Furthermore, the width of the elements on both sides of the joint line used in the preliminary stamping analysis may not necessarily be the same as the weld width. Alternatively, the width of the elements on both sides of the joint line can be set as the sum of the widths of multiple elements on each side of the joint line. Or, the width of the elements on both sides of the joint line can be a value calculated based on the sum of the widths of the elements on both sides of the joint line.

[0121] exist Figure 8 In step S02, the stamping analysis unit 12 uses the analysis model data with joint lines obtained in step S01 to perform a preliminary stamping analysis (simulation). In the preliminary stamping analysis, the deformation of elements is calculated when the welded component represented by the analysis model data with joint lines has been stamped. The stamping analysis may also include heat treatment analysis.

[0122] Figure 10 It shows the... Figure 9 The figure shows a partial example of the results obtained from stamping analysis of the welded component model. Figure 10In the example shown, the width W02 of the elements on both sides of the joint line in the data of the stamped welded component corresponds to the width of the weld. Based on the width W02 of the elements on both sides of the joint line calculated through stamping analysis, information representing the change in weld width due to stamping is obtained.

[0123] Figure 11 It is shown Figure 9 and Figure 10 A graph showing the width values ​​of the elements on both sides of the joint line in the welded component model shown. Figure 11 In the curve diagram, the horizontal axis represents the distance from the inner circumference end along the long side of the joint line, and the vertical axis represents the width of the elements on both sides of the joint line. Figure 11 In the example shown, the width W01 of the elements on both sides of the joint line before stamping is uniform along the long side of the joint line. The width W02 of the elements after stamping, obtained through analysis, is not uniform along the long side and differs from the width W01 before stamping. The relationship between the position of the joint line along the long side and the width of the elements on both sides of the joint line changes due to stamping. For example... Figure 11 As shown, the relationship between the position of the joint line along its long side and its width W02 illustrates the change in weld width due to stamping. Thus, the relationship between the position of the joint line along its long side and the change in its width (e.g., expansion or contraction) can be determined based on the width variation of the analysis element sandwiching the joint line (boundary line).

[0124] exist Figure 8 In step S03, the weld width design unit 13 determines the initial value of the weld width at each position along the long side of the joint line based on the stamped width W02 obtained from the analysis in step S02. Data representing the relationship between the initial value of the weld width and its position along the long side is generated as initial value data. For example, the value obtained by correcting the width W01 of the element based on the degree of difference between the stamped element width W02 and a predetermined target value W04 can be set as the new initial value W03. Figure 11 In the example shown, the target value W04 of the width of the formed element is set to the same value as the initial value W01 before stamping in the analysis of S02 (1 mm in the figure). In this example, the initial value W03 (=W04×(W01 / W02)=W01×(W01 / W02)) is determined by multiplying the target value W04 by the reciprocal of the rate of change of the analysis result due to stamping (W02 / W01).

[0125] The weld width design unit 13 sets the width of the weld element EB in the analysis model data before forming based on the initial value data generated by S03. For example, the width of the weld element EB, which is set to be uniform in the long side direction D, can be corrected based on the initial value data. As a result, the weld width of the welded component of the analysis object can be determined.

[0126] The model acquisition unit 11 acquires analysis model data with the width of the set element EB based on the weld width design data (S11). Subsequent steps S11 to S14 can then be used with… Figure 2 The same applies to S11 to S14 shown.

[0127] (Example 2 of the operation of a manufacturing system)

[0128] In manufacturing system 2, when manufacturing welded components, control unit 23 acquires weld width design data. This weld width design data is generated by design system 1. Control unit 23 makes the weld width design data accessible by reading it into memory, etc. In manufacturing system 2, the first plate P1 and the second plate P2 are supported with their ends joined together. Control unit 23 controls heat input device 21 and moving device 22 to weld the first plate P1 and the second plate P2. The controlled moving device 22 moves the heat input position of heat input device 21, i.e., the molten portion, along the joint line (long side direction of the butt joint) between the ends of the first plate P1 and the second plate P2. Control unit 23 controls the amount of heat input for melting using heat input device 21 based on the weld width design data, while controlling the moving device 22 to move the molten portion. Thus, the welding position and heat input amount along the joint line are controlled. In the control, the relationship between the position on the butt joint line and the amount of heat input corresponds to the relationship between the position on the long side of the weld and the width of the weld, as expressed by the weld width design data.

[0129] Figure 12 This is a flowchart illustrating an example of the operation of the control unit 23. Figure 12 In the example shown, laser welding begins with an initial output of P (kW) and an initial speed of V (m / s) (S21). The welding speed is the speed at which the laser spot (heat input point) moves in the welding direction. Let the welding direction be the long side direction of the joint between the ends of the first plate P1 and the second plate P2. The long side direction of the joint is along the direction of the weld line. Welding begins from one end along the long side direction of the joint. That is, the starting point of the heat input (the initial position of the heat input point) is one end of the weld line.

[0130] The laser output is determined as P·R(x) (S22) based on the position x (mm) in the welding direction. Here, x (mm) is the distance traveled from the starting point of the heat input, and R(x) is determined using corresponding data representing the relationship between the distance x and the control value R. This corresponding data can be, for example, data such as a table or a function. The relationship between the distance x and the control value R represented by this corresponding data corresponds to the relationship between the position of the weld along its long side and the weld width in the weld width design data. That is, R(x) is a value based on the weld width design data.

[0131] If the laser output P·R(x) determined by S22 is within a predetermined setting range ("Yes" in S23), the welding speed is maintained (S24). The setting range can be set to a range of laser output that ensures sufficiently stable welding. If "No" is set in S23, the welding speed is changed to V / R(x) (S25). R(x) is a value based on the weld width design data.

[0132] Furthermore, the output control value R(x) used in S22 may not be the same as the welding speed control value R(x) used in S25. For example, the output control value R(x) in S22 can be determined based on the relationship between the weld width and the output value (e.g., a function) obtained in advance through experiments, etc., and the weld width design data. Similarly, the welding speed control value R(x) in S25 can be determined based on the relationship between the weld width and the welding speed obtained in advance through experiments, etc., and the weld width design data.

[0133] When the moving distance x reaches the end distance ("Yes" in S26), the control unit 23 stops the laser output and ends the welding. Figure 12 The process shown allows for control of the weld width by adjusting the laser output and welding speed based on weld width design data. This weld width design data is used as a welding control parameter. As a result, it is possible to manufacture welded components where the weld width after stamping is close to the target value.

[0134] Furthermore, the actions of the control unit 23 are not limited to Figure 12 The example shown. For example, the control unit 23 can also change the filler supply amount based on the distance x. The control unit 23 can also determine the filler supply amount at distance x based on the control value R(x) based on the weld width design data. In this case, the control value R(x) can be determined based on the relationship between the weld and the filler supply amount obtained in advance through experiments, etc., and the weld width design data.

[0135] In the above-described embodiment, in design system 1, based on the shape of the stamped product obtained through structural design, data showing not only the change in weld position before and after stamping but also the change in width can be obtained through reverse analysis of the blank. Therefore, design values ​​for the weld of the blank component can be obtained, taking into account the movement and width change of the weld caused by stamping. Furthermore, in design system 1, weld width design data representing the relationship between the position and width of the weld in the long side direction is generated. Based on the weld width design data, the change in the width of the weld in the long side direction of the welded component before stamping can be expressed as a function of the welding distance (e.g., a function of the position of the weld line in the long side direction). Therefore, in manufacturing system 2, parameters based on the weld width design data can be used as control parameters for the weld width (e.g., heat input, welding speed, melt width, or filler supply amount). Welding control can be performed using these control parameters, allowing the heat input, welding speed, or filler supply amount to vary according to the welding distance. Therefore, it is possible to obtain a weld with a width that meets the target value (e.g., a constant width in the long side direction) after stamping.

[0136] The present invention is not limited to these, and can be applied, for example, to welded components formed by joining multiple plates with different strengths and thicknesses. According to the above embodiments, in the welded component before stamping, the weld width varies along the long side of the weld. Such a welded component is also one embodiment of the present invention. The stamped articles described below are included in embodiments of the present invention.

[0137] The stamping method for the welded components using the present invention is not particularly limited. For example, the welded components manufactured through the above embodiments can be stamped with at least one of the following deformations: tensile flange deformation, shrinkage flange deformation, and protrusion deformation. In this case, the weld width of the portion of the stamped article undergoing at least one of the following deformations can be made uniform. Stamped articles in which the weld width is uniform at the portion where tensile flange deformation, shrinkage flange deformation, or protrusion deformation occurs are also included in embodiments of the present invention. In addition, in the stamped article, the weld width of the portion where tensile flange deformation, shrinkage flange deformation, or protrusion deformation occurs can be made equal to the weld width of other portions where no such deformation occurs or where the deformation is smaller. Such stamped articles in which the weld width of the portion where tensile flange deformation, shrinkage flange deformation, or protrusion deformation occurs is equal to the weld width of other portions are also included in embodiments of the present invention. Furthermore, the method of equal weld width includes not only cases where the weld width is strictly the same, but also cases where the weld width has a slight difference of ±13% within the range of manufacturing tolerances. As an example of this method, in a stamped product containing at least one of a portion where tensile flange deformation occurs, a portion where shrinkage flange deformation occurs, and a portion where protrusion deformation occurs, the ratio of the minimum to the maximum width of the weld along its entire long side can be 77% ≤ minimum / maximum ≤ 100%. Typical examples of tensile flange deformation, shrinkage flange deformation, and protrusion deformation during stamping are given below.

[0138] Figure 13 This is a diagram illustrating a typical example of shrinkage flange deformation in stamping. Figure 13The stamped article 101 shown includes a cylindrical deep-drawn flange. The stamped article 101 has a circular top plate 31, a cylindrical longitudinal wall 41 extending from the outer periphery of the top plate 31, and a flange 51. The flange 51 extends radially outward from the end of the longitudinal wall 41 opposite to the top plate 31. The stamped article 101 is formed, for example, by deep drawing a welded component of a flat sheet. In deep drawing, generally, while using a die (e.g., a blank holder and a punch) to hold the peripheral portion of the sheet metal to constrain deformation in the thickness direction of the peripheral portion, a convex die (e.g., a punch) presses the central portion of the sheet metal into the recess of a concave die (e.g., a punch), thereby forming the sheet metal by pressing the peripheral portion toward the central portion. During forming, the material flows in the direction of the arrow shown in the figure. A portion of the flange 51 becomes the portion where shrinkage flange deformation occurs. In this example, at the portion where the shrinkage flange deformation occurs, deformation occurs that contracts in the direction perpendicular to the material flow (circumferential direction) and stretches in the direction of material flow (radial direction). At the portion where the shrinkage flange deformation occurs, the ridge line intersecting the direction of material flow bends in a manner that convexes in the direction opposite to the material flow. Figure 13 In the example, the top plate 31 and the longitudinal wall 41 are the parts that do not undergo shrinkage flange deformation or undergo relatively small deformation. In such cases... Figure 13 When the longitudinal wall 41 is approximately perpendicular to the flange 51, the shrinkage flange deformation at the longitudinal wall 41 is negligible compared to that at the flange 51. The top plate 31 remains largely undeformed during forming. For example, if the weld is located in the portion where shrinkage flange deformation occurs (flange 51), the weld width of the pre-formed welded component can be set in a way that makes the weld width at the shrinkage flange deformation portion uniform after forming. Alternatively, it can be configured such that, in the stamped product, the weld width of the portion where shrinkage flange deformation occurs is equal to the weld width of other portions where shrinkage flange deformation does not occur or where deformation is relatively small. For example, in the pre-formed welded component, the weld width of the portion where shrinkage flange deformation occurs can be set larger than the weld width of other portions where shrinkage flange deformation does not occur or where deformation is relatively small. In this case, the portion where shrinkage flange deformation occurs includes the portion with the maximum width, and the other portions include portions with a width of 80% to 91% of the maximum width.

[0139] Figure 14 This is a diagram illustrating a typical example of a stretch flange in stamping. Figure 14The stamped article 102 shown includes a cylindrical expanded surface. The stamped article 102 has a circular top plate 32 with a central through hole, a cylindrical longitudinal wall 42 extending from the outer periphery of the top plate 32, and a flange 52. The flange 51 extends radially outward from the end of the longitudinal wall 42 opposite to the top plate 32. The stamped article 102 is formed, for example, by forming a welded component of a flat plate with a through hole using a die similar to that used for deep drawing. In the case of a through hole, the material flows in the direction of the arrow shown in the figure during forming. A portion of the top plate 32 becomes the portion where tensile flange deformation occurs. In this example, in the portion where tensile flange deformation occurs, stretching deformation occurs in the direction perpendicular to the material flow (circumferential direction), and contraction deformation occurs in the direction of material flow (radial direction). In the portion where tensile flange deformation occurs, the ridge line intersecting the direction of material flow bends in a convex manner towards the direction of material flow. Figure 14 In the example, the longitudinal wall 42 and the flange 52 are portions that do not undergo tensile flange deformation or have relatively small deformation. For example, if the weld is located in the portion where tensile flange deformation occurs (top plate 32), the weld width of the pre-formed welded component can be set in a way that makes the weld width at the portion where tensile flange deformation occurs uniform after forming. Alternatively, it can be configured such that the weld width of the portion where tensile flange deformation occurs in the stamped part is equal to the weld width of other portions where tensile flange deformation does not occur or has relatively small deformation. For example, in the pre-formed welded component, the weld width of the portion where tensile flange deformation occurs can be set smaller than the weld width of other portions where tensile flange deformation does not occur or has relatively small deformation. In this case, other portions include the portion with the maximum width, and the portion where tensile flange deformation occurs includes the portion with a width of 80% to 91% of the maximum width.

[0140] Figure 15 This is a diagram illustrating a typical example of protruding deformation in stamping. Figure 15The stamped article 103 shown includes a ball-shaped protruding surface. The stamped article 103 has a mountain-shaped protrusion 43 with an internal space and a flange 53 extending from the root of the protrusion 43. The stamped article 103 is formed by stamping a welded component of a flat plate. For example, by fixing the periphery of the sheet metal and pressing the central surface with a die to make it protrude, forming with protrusion deformation is possible. During forming, the material flows in a direction that expands towards the top 43a, including the apex of the protrusion 43. The top 43a becomes the part where protrusion deformation occurs. The portion of the flange 53 is the part that does not undergo protrusion deformation or has relatively small deformation. In this example, in the portion where protrusion deformation occurs, deformation is generated in two axial directions that are stretched in the direction of material flow. For example, if the weld is located in the portion where protrusion deformation occurs (top 43a), the weld width of the welded component before forming can be set in a way that makes the weld width at the portion where protrusion deformation occurs uniform after forming. Furthermore, it is possible to configure the weld width of the portion where protruding deformation occurs to be equal to the weld width of other portions where protruding deformation does not occur or where deformation is relatively small. For example, in a welded component before forming, the weld width of the portion where protruding deformation occurs can be set to be smaller than the weld width of the portion where protruding deformation does not occur or where deformation is relatively small. In this case, the other portions include the portion with the maximum width, and the portion where protruding deformation occurs includes the portion with a width of 80% to 91% of the maximum width.

[0141] Figure 16 This is a diagram showing an example of a stamped article manufactured by forming with stretching flange deformation and shrinkage flange deformation. Figure 16 The stamped article 104 shown is a hat component with a hat-shaped cross-section and curved along its long side. The stamped article 104 has a top plate 34, a pair of longitudinal walls 44 extending from both ends of the top plate 34, and a long flange 54a and a short flange 54b extending from the ends of the pair of longitudinal walls 44 opposite to the top plate 34, respectively. The edges between the top plate 34 and the longitudinal walls 44, the edges between the long flange 54a and the longitudinal walls 44, and the edges between the short flange 54b and the longitudinal walls 44 are curved in an arc-shaped manner in the same direction. The short flange 54b is shorter than the long flange 54a. The edges of the short flange 54b are formed to be located on the inner periphery of the edges of the long flange 54a. The stamped article 104 is a... Figure 16 The flat, fan-shaped welded component 104B, indicated by dashed lines, is formed by stamping. Figure 16In the example shown, the long flange 54a is the portion undergoing shrinkage flange deformation. The short flange 54b is the portion undergoing stretching flange deformation. The ridge line between the long flange 54a, which undergoes shrinkage flange deformation, and the longitudinal wall 44 bends in a manner opposite to the material flow during molding. The ridge line between the short flange 54b, which undergoes stretching flange deformation, and the longitudinal wall 44 bends in a manner convex in the material flow direction. The top plate 34 and the longitudinal wall 44 are portions that do not undergo either shrinkage flange deformation or stretching flange deformation, or where these deformations are relatively small. Figure 16 In the case where the longitudinal wall 44 is nearly perpendicular to the flanges 54a and 54b, the tensile flange deformation or shrinkage flange deformation of the longitudinal wall 44 is negligible compared to the flanges 54a and 54b. The top plate 34 does not deform significantly during forming. For example, if the weld is located at at least one of the portions where shrinkage flange deformation occurs (long flange 54a) and the portions where tensile flange deformation occurs (short flange 54b), the weld width of the pre-forming welded member 104B can be set in a way that makes the weld width at the portions where shrinkage flange deformation or tensile flange deformation occurs uniform after forming. Furthermore, it is possible to configure the weld width at the portions where shrinkage flange deformation or tensile flange deformation occurs to be equal to the weld width at other portions where neither shrinkage nor tensile flange deformation occurs, or where the deformation is relatively small. For example, in a pre-formed welded component, the weld width of the portion where tensile flange deformation occurs can be set smaller than the weld width of other portions where neither tensile nor shrinkage flange deformation occurs, or where deformation is minimal. Conversely, in a welded component, the weld width of the portion where shrinkage flange deformation occurs can be set larger than the weld width of other portions where neither tensile nor shrinkage flange deformation occurs, or where deformation is minimal. Additionally, for example, a weld may sometimes include portions where tensile flange deformation occurs, portions where shrinkage flange deformation occurs, and other portions where neither tensile nor shrinkage flange deformation occurs, or where deformation is minimal. In this case, as an example, the portion where shrinkage flange deformation occurs includes the portion with the largest width in the entire weld. Other portions where deformation does not occur or where deformation is minimal include portions whose width is 80% to 91% of the maximum width. Alternatively, the portion where tensile flange deformation occurs may also include portions whose width is 80% to 91% of the maximum width of other portions.

[0142] For example, in the stamping of automotive parts, as a typical example, Figure 13 , Figure 14 and Figure 15The diagram shows a common situation where tensile flanges, contraction flanges, and protrusions, among other deformed portions, coexist. Therefore, in stamped products of welded components, where welds are arranged across different deformed portions, the weld width sometimes varies for each portion. To address this, by setting the weld width of the welded component before forming based on the weld width design data in the above embodiment, it is possible to control the weld width after forming, taking into account the different deformations during forming. For example, it is possible to make the weld width uniform across different deformed portions after forming.

[0143] Figure 17 This is a diagram showing an example of a stamped article manufactured by forming with stretching flange deformation and shrinkage flange deformation. Figure 17 The stamped product 105 shown is a center pillar. The stamped product 105 has a top plate 35, a pair of longitudinal walls 45, and a pair of flanges 55. The pair of longitudinal walls 45 extend from both ends of the top plate 35. The pair of flanges 55 extend from the ends of the pair of longitudinal walls 45 opposite to the top plate 35. The pair of longitudinal walls 45 face each other. The pair of flanges 55 extend from the ends of the pair of longitudinal walls 45 in a direction away from each other. The edges between the top plate 35 and the longitudinal walls 45, and the edges between the longitudinal walls 45 and the flanges 55, both extend along the long side of the stamped product 105. The cross-section of the stamped product 105 perpendicular to the long side is a hat-shaped shape. The stamped product 105 is a... Figure 17 The flat, welded component 105B, with a shape indicated by dashed lines, is formed by stamping. During forming, the material flows in the direction of the arrow. The flange 55 includes a portion 55C (the area enclosed by the dashed lines) that undergoes shrinkage flange deformation and a portion 55N (the area enclosed by the dashed lines) that undergoes tensile flange deformation. Figure 17In the example, the portions of a pair of flanges 55 facing each other are the portions 55N where tensile flange deformation occurs. The portions of flanges 55 corresponding to the curved portions of the ridges between the flanges 55 and the longitudinal wall 45 are either portions 55N where tensile flange deformation occurs or portions 55C where contraction flange deformation occurs. The ridges of portions 55N where tensile flange deformation occurs are curved in a manner convex toward the material flow direction. The ridges of portions 55C where contraction flange deformation occurs are curved in a manner convex toward the direction opposite to the material flow direction. As an example, weld 65 is located at a position passing through portions 55N where tensile flange deformation occurs, longitudinal wall 45, and top plate 35. In this case, the weld width of the pre-formed welded component 105B may be set in such a way that the weld width becomes uniform in portions 55N where tensile flange deformation occurs after forming. Alternatively, it may be configured such that, in the stamped product, the weld width of portions 55N where tensile flange deformation occurs becomes equal to the weld width of other portions (longitudinal wall 45 and top plate 35) where tensile flange deformation does not occur. Alternatively, for example, if the weld passes through the portion 55C where shrinkage flange deformation occurs, the weld width of the welded component 105B can be set in a way that makes the weld width at the portion 55C where shrinkage flange deformation occurs uniform in the stamped product. Furthermore, it can be configured such that the weld width at the portion 55C where shrinkage flange deformation occurs is equal to the weld width at other portions where shrinkage flange deformation does not occur. For example, it can be configured such that the weld width at the portion 55N where tensile flange deformation occurs, the weld width at the portion 55C where shrinkage flange deformation occurs, and the weld width at other portions where neither tensile nor shrinkage flange deformation occurs are equal in the stamped product.

[0144] Figure 18 It is shown Figure 17 The diagram shows the welded component 105B. The welded component 105B includes a first plate 105B1 and a second plate 105B2, the sides of the first plate 105B1 and the sides of the second plate 105B2 being joined by welding. A weld 65B between the first plate 105B1 and the second plate 105B2 extends from one end of the welded component 105B to the other end. The weld 65B includes a portion with a relatively large width and a portion with a relatively small width. The portion with a relatively large width includes the widest portion of the entire weld 65B, i.e., the portion with the maximum width W11. The width W12 of the weld in the portion with the relatively small width is 80% to 91% of the maximum width W11 of the weld 65B.

[0145] exist Figure 18In the example, portions with a width of 80% to 91% of the maximum width are provided at both ends of weld 65B. These portions are provided at the parts where tensile flange deformation occurs during stamping. Thus, in the welded component 10, the weld width of the portions where tensile flange deformation, shrinkage flange deformation, or protrusion deformation (hereinafter sometimes referred to as "tensile flange deformation, etc.") occurs during stamping can be different from the weld width of other portions where no such deformation occurs or where the deformation is smaller. Therefore, the weld width after stamping of the portions where tensile flange deformation, etc., occurs during stamping can be made equal to the weld width after stamping of other portions. For example, assuming the deformation caused by tensile flange deformation is 10% to 25%, by making W12 / W11 80% to 91% as described above, the weld width after stamping of the portions where tensile flange deformation, etc., occurs can be made to differ from the width of other portions by within ±13%. Figure 18 In the example, portions with a width of 80% to 91% of the maximum width are provided at both ends of weld 65B. Thus, in... Figure 17 In the structure shown, where weld seams 65B are arranged across a pair of flanges 55, a pair of longitudinal walls 45, and a top plate 35, it is easy to make the weld seam width after stamping in the portion that undergoes tensile flange deformation during stamping equal to the weld seam width after stamping in other portions. Furthermore, in Figure 18 In the example, the width of weld 65B is more than 80% of its maximum width along the entire long side of weld 65B. Thus, when the weld of the welded component 10 passes through areas where tensile flange deformation is predicted to occur during stamping and areas where deformation is predicted to be minimal or nonexistent, by making the width of the weld more than 80% along the entire long side of weld, it is easy to design the weld width according to the predicted deformation.

[0146] As described above, by making the weld width of the portion where tensile flange deformation occurs the same as the weld width of other portions, the weld width of the stamped product can be made uniform. This allows the individual sheet metal components included in the welded plate assembly to be distributed to the designed areas within the stamped product. For example, the difference between the impact performance predicted by CAE and the actual impact performance of the stamped product can be minimized. Furthermore, by making the weld width of the product uniform, the process of removing oxide scale from the welds of the product becomes easier. For example, the area to be shot peened can be reduced. Additionally, the weld appearance is improved when the stamped product is used as an external component. Previously, when welds were placed in portions where tensile flanges, shrinkage flanges, or protrusion deformation occurred, the impact performance and other properties of the stamped product were affected; therefore, the position of the weld line was sometimes limited in the design. In this embodiment, the weld width of the portion where tensile flanges, shrinkage flanges, or protrusion deformation occurred after stamping is configured to be the same as the weld width of other portions. Therefore, even when the weld width is configured in areas where tensile flange deformation or similar phenomena occur, the impact of weld width variations on the performance of the stamped product can be suppressed. As a result, the design freedom for the weld line configuration can be increased, and the performance of the stamped product can be ensured.

[0147] exist Figure 17 In the example shown, the top plate 35 and the longitudinal wall 45 are portions that do not undergo any of the tensile flange deformation, contraction flange deformation, or protrusion deformation, or whose deformation is relatively small. At least a portion of the top plate and the longitudinal wall may sometimes undergo tensile flange deformation, contraction flange deformation, or protrusion deformation. For example, when the angle of the flange of the longitudinal wall deviates significantly from a right angle, the longitudinal wall may sometimes undergo tensile flange deformation or contraction flange deformation. As another example, in the case of a channel-shaped member without flanges, but formed by the top plate and a pair of longitudinal walls, tensile flange deformation or contraction flange deformation may sometimes occur in the longitudinal wall.

[0148] In the above Figure 16 and Figure 17In the example shown, the stamped article has a top plate, a pair of longitudinal walls, and a pair of flanges. That is, the stamped article has a hat-shaped cross-section. In this type of stamped article, the ridge between the flange and the longitudinal walls has a curved portion that bends when viewed from a direction perpendicular to the flange surface. The portion of the flange extending from this curved portion in the direction opposite to the material flow is the portion that has undergone tensile flange deformation or contractile flange deformation. The portion of the flange extending from the ridge that bends in a manner convex in the direction of material flow when viewed from a direction perpendicular to the flange surface is the portion that has undergone tensile flange deformation. That is, the portion of the flange extending outward from the portion of the ridge that bends in a manner convex in the direction opposite to the direction of extension of the ridge between the flange and the longitudinal walls (the inwardly convex curved portion) is the portion that has undergone tensile flange deformation. The portion of the flange extending from the ridge that bends in a manner convex in the direction opposite to the material flow when viewed from a direction perpendicular to the flange surface is the portion that has undergone contractile flange deformation. That is, the portion of the flange that extends outward from the portion of the ridge line that bends in a convex manner in the direction of extension from the ridge line between the flange and the longitudinal wall (the outwardly convex bending portion) is the portion that has undergone shrinkage flange deformation. In this structure, it is preferable to form the weld in such a way that the width of the weld in the portion of the flange that extends outward from the bending portion of the ridge line between the longitudinal wall and the flange is equal to the width of the weld in other portions.

[0149] The stamped articles to which this invention can be applied are not limited to the examples described above. For example, in addition to the center pillar, this invention can also be applied to vehicle structural components such as A-pillars, side beams, bumpers, top beams, floor components, and front components. For example, in addition to structural components such as pillars whose edges are curved when viewed from the roof side, this invention can also be applied to components such as front or rear components that are curved in a direction perpendicular to the surface of the roof (vertical direction).

[0150] In both cold and hot pressing processes, the weld width can change due to deformation caused by the stamping process. This invention can be applied to both cold-pressed and hot-pressed products, thereby suppressing the impact of weld width variations on the performance of the stamped products. In hot pressing, the weld width variation tends to be greater. When this invention is applied to hot-pressed products, the above effect is even more significant.

[0151] The welded components to which this invention can be applied are not limited to welded components formed by joining multiple plates of different strengths or thicknesses. For example, this invention can be applied to welded components formed by joining multiple plates of the same strength or multiple plates of the same thickness. In such welded components, the weld width may also vary during stamping. Furthermore, as an example, this invention can be ideally applied to hot-pressed welded components, i.e., welded components made from materials used in hot-pressed products.

[0152] Furthermore, the present invention is not limited to the embodiments described above. In the embodiments described above, the elements of the weld in the analysis model data are arranged between the elements of the first plate and the elements of the second plate. For example, the elements of the first plate and the elements of the second plate, which are connected to each other by a joint line, can also be used as the elements of the weld. In addition, in the embodiments described above, an example of performing multiple stamping analyses is shown, but weld width design data can also be generated by a single stamping analysis. Furthermore, the weld width design data is not limited to data representing the width of the weld at each position along the long side direction of the weld as described above. The weld width design data can also be, for example, data representing the rate of change of the weld along the long side direction of the weld. The form of the weld width design data is not particularly limited, for example, it can be discrete value data, tabular data, or data as a function of position. In addition, the welded component can also be formed by joining three or more plates by welding. In this case, the welded component has two or more welds. Welded components or stamped products that include two or more welds are also included in the embodiments of the present invention. At least one of the two or more welds in a welded component may include a portion whose width is 80% to 91% of the maximum width of that weld. Alternatively, in at least one of the two or more welds in a stamped part, the width of the weld where tensile flange deformation occurs may be equal to the width of the welds in other portions where deformation is minimal or nonexistent. Furthermore, the analytical model data may represent analytical model data for a welded component consisting of three or more sheet metal pieces.

[0153] The foregoing has described one embodiment of the present invention, but the above embodiment is merely an example for implementing the present invention. Therefore, the present invention is not limited to the above embodiment, and can be implemented by appropriate modifications without departing from its spirit.

[0154] Explanation of reference numerals in the attached figures

[0155] 1: Design system; 2: Manufacturing system; 11: Model acquisition unit; 12: Stamping and forming analysis unit; 13: Weld width design unit; 21: Heat input device; 22: Moving device; 23: Control unit.

Claims

1. A method for designing the weld width of a welded component, comprising: The model acquisition process involves acquiring analysis model data, wherein the analysis model data represents data of a welded component having a first plate and a second plate that are joined together, and the analysis model data includes elements of the first plate, elements of the second plate, and elements of the weld between the ends of the first plate and the ends of the second plate. The stamping analysis process uses the analysis model data to perform stamping analysis, thereby calculating the deformation of the first sheet metal, the second sheet metal, and the weld seam elements when the welded component has been stamped; and The weld width design process determines the design value of the weld width at each position along the long side of the weld of the welded component before stamping, based on the change in the width of the weld element due to stamping, obtained from the calculation results of the stamping analysis process. This generates weld width design data that represents the relationship between the position of the weld along the long side before stamping and the design value of the weld width.

2. The method for designing the weld width of welded components according to claim 1, wherein, The model acquisition process, the stamping analysis process, and the weld width design process are executed more than twice. In the model acquisition process after the second time, analytical model data containing elements of the weld having a width based on the weld width design data generated through the previous weld width design process is acquired.

3. The method for designing the weld width of welded components according to claim 1 or 2, wherein, Also includes: The process of obtaining the model with the joint line involves obtaining the analysis model data with the joint line. The analysis model data with the joint line represents the data of a welded component with a first plate and a second plate that are joined to each other. The analysis model data with the joint line has elements of the first plate and elements of the second plate, and includes the joint line where the elements of the first plate and the elements of the second plate are connected as the joint line between the first plate and the second plate. In the preliminary stamping analysis process, the stamping analysis is performed using the analysis model data with the joint line, thereby calculating the element deformation of the first plate and the second plate when the welded component shown in the analysis model data with the joint line is stamped. as well as The initial value generation process determines the initial value of the weld width corresponding to the joint line based on the changes in the width of the elements of the first and second plates on both sides of the joint line due to stamping, obtained from the calculation results of the preceding stamping analysis process. This generates initial value data representing the relationship between the position of the weld along its long side and the initial value of the weld width. In the model acquisition process, the analysis model data containing elements of the weld having a width based on the initial value data generated through the initial value generation process is acquired.

4. The method for designing the weld width of welded components according to claim 1 or 2, wherein, In the weld width design process, the design value of the weld width is determined so that the changed weld width is close to the target value.

5. The method for designing the weld width of welded components according to claim 1 or 2, wherein, The weld width design data represents the distribution of the design values ​​of the weld width along the long side.

6. The method for designing the weld width of welded components according to claim 1 or 2, wherein, Weld width design data shows how the width of the weld should be set at various locations along the long side of the weld.

7. A method for manufacturing a welded component, comprising each step of the weld width design method according to claim 1 or 2, wherein the manufacturing method comprises the following steps: Obtain the weld width design data, which represents the relationship between the position of the weld seam along the long side of the welded component and the width of the weld seam; as well as In the welding process, the ends of the first plate and the second plate are joined together, and the molten part travels along the butt joint line, thereby welding the ends of the first plate and the second plate together. In the welding process, the amount of heat input for melting is controlled based on the weld width design data while the molten part is moved.

8. The method for manufacturing welded components according to claim 7, wherein, In the welding process, the amount of filler supplied is controlled based on the weld width design data while the molten portion is moved.

9. A weld width design system for welded components, comprising: The model acquisition department acquires and analyzes model data, among which... The analysis model data represents the data of a welded component having a first plate and a second plate joined together. The analysis model data includes elements of the first plate, elements of the second plate, and elements of the weld between the ends of the first plate and the ends of the second plate. The stamping analysis unit uses the analysis model data to perform stamping analysis, thereby calculating the deformation of the elements of the first sheet metal, the second sheet metal, and the elements of the weld when the welded component has been stamped. as well as The weld width design unit determines the design value of the weld width at each position along the long side of the weld of the welded component before stamping, based on the change in the width of the weld element due to stamping, obtained from the calculation results of the stamping analysis unit. It generates weld width design data that represents the relationship between the position of the weld along the long side before stamping and the design value of the weld width.

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