Pressed parts for the car body
By incorporating uneven surfaces in flanges of pressed parts, stress-induced deformation is mitigated, ensuring precise alignment and improved appearance of vehicle body components.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- MITSUBISHI MOTORS CORP
- Filing Date
- 2024-12-17
- Publication Date
- 2026-06-29
AI Technical Summary
Pressed parts with curved or bent surfaces forming flanges experience stress-induced deformation, affecting the fit and appearance of vehicle body components.
The formation of uneven surfaces, such as beads or concavo-convex parts, along the extending direction of flanges in pressed parts to mitigate stress and prevent deformation.
The uneven surfaces absorb stress during flange formation, ensuring precise alignment and improved appearance of vehicle body parts by preventing unintended deformation.
Smart Images
Figure 2026105887000001_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the shape of pressed parts of a vehicle body.
Background Art
[0002] Vehicles are configured by assembling vehicle body parts with complex shapes. Many of the vehicle body parts that form part of the outer shape of a vehicle, such as a bonnet, are pressed parts having curved surfaces or bent surfaces formed of steel sheets or the like. Among the vehicle body parts having such curved surfaces or bent surfaces, there are some in which the ends are further folded back to form flanges.
[0003] For example, in Patent Document 1, the end of a curved pressed part (panel member) is bent to form a flange.
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0005] However, for a pressed part that is curved or bent, if it is bent to form a flange including the curved or bent range, stress acts on the flange and it may deform, and the parts around the flange may also deform. For example, in adjacent vehicle body pressed parts such as a bonnet and a front fender of an automobile, if at least one of the ends is deformed, even if it is a slight deformation, the butting surface may not match and the appearance of the vehicle may be deteriorated.
[0006] This disclosure has been made to solve such problems, and an object thereof is to provide a highly accurate pressed part of a vehicle body that has a curved shape or a bent shape and in which a flange is formed by bending including the curved or bent range. [Means for solving the problem]
[0007] To achieve the above objective, the pressed part of the present disclosure is a metallic pressed part for the outer panel of a vehicle body having a curved or bent shape, and having an end bent along a ridge that is set to include the curved or bent range to form a flange, wherein the flange has an uneven portion formed along the extending direction of the flange. [Effects of the Invention]
[0008] According to the pressed body parts of the present disclosure, the formation of uneven surfaces at the ends allows the uneven surfaces to mitigate and absorb stress generated in the flange when the ends of pressed parts having curved or bent portions are bent to form a flange, thereby suppressing changes to the flange and surrounding parts of the pressed part. This makes it possible to produce highly accurate pressed parts that have a curved or bent shape and a flange. [Brief explanation of the drawing]
[0009] [Figure 1] This is a top view of the hood of a vehicle having a pressed part according to one embodiment of the present disclosure. [Figure 2] This is a vertical cross-section of the hood before assembly. [Figure 3] This is a longitudinal cross-sectional view showing the assembly procedure for the hood. [Figure 4] This is an explanatory diagram of the procedure for forming the flange at the end of the outer component. [Figure 5] This is a top view showing the shape of the outer part before flange formation. [Figure 6] This is a longitudinal cross-sectional view of the end of the outer part before flange formation. [Figure 7] This is a front view of the end of the outer part before flange formation. [Figure 8] This is a perspective view showing the shape of the die blade of the press machine according to this embodiment. [Figure 9]This is an explanatory diagram showing the procedure for forming a bead on a pressed part using a press machine according to this embodiment. [Modes for carrying out the invention]
[0010] Embodiments of this disclosure will be described below with reference to the drawings. Figure 1 is a top view of the hood 1 of a vehicle having a pressed part according to one embodiment of the present disclosure. Figure 2 is a longitudinal cross-sectional view of the hood 1 before assembly, and is a cross-sectional view taken in the vehicle width direction. Figure 3 is a longitudinal cross-sectional view showing the assembly procedure of the hood 1. Note that Figure 2 is a drawing of the cross-section of part AA shown in Figure 1, with the outer part 2 on the lower side. Figure 3 is an enlarged view of the end of the hood.
[0011] As shown in Figure 1, the pressed parts for the vehicle body according to this disclosure are pressed parts formed by shearing and bending a steel plate with a press machine, such as the outer part 2 of the vehicle's hood 1. The hood 1 is a component that makes up the body of, for example, a plug-in hybrid vehicle (PHEV) or a hybrid vehicle (HEV). A PHEV refers to a hybrid vehicle that can be externally charged to or powered from a battery. A PHEV has a charging port (inlet) for inserting a charging cable into which power is supplied from an external charging facility, and an outlet for external power supply.
[0012] The hood 1 is formed by combining an outer part 2, which is a pressed part, and an inner part 3, which is made of heat-resistant resin or the like. Outer part 2 is formed from a steel sheet having a tensile strength of 270 [N / mm] or more and 340 [N / mm], such as cold-rolled steel sheet SPCC or hot-rolled mild steel sheet SPHC.
[0013] Outer part 2 is curved relative to the flat plate extending in the vehicle's longitudinal and width directions (left-right direction), and there are also places where it is bent at a slight angle. Before assembling the inner part 3, the outer part 2, as shown in FIG. 2, has its left and right ends bent at an angle of about 90 to 105 degrees to form the flange 11.
[0014] As shown in FIG. 3, after the inner part 3 is fitted inside the outer part 2 having the flange 11, the bonnet 1 is manufactured by bending the flange 11 with a press or the like to sandwich and fix the left and right ends of the inner part 3. FIG. 4 is an explanatory diagram of the flange forming procedure at the end of the outer part 2. FIG. 5 is a top view showing the shape of the outer part 2 before flange formation. FIG. 6 is a longitudinal sectional view of the end of the outer part 2 before flange formation. FIG. 7 is a front view of the end face part of the outer part 2 before flange formation. Note that FIG. 6 is a sectional view of the B-B part described in FIG. 5. FIG. 7 is a view seen from C described in FIG. 5.
[0015] As shown in FIG. 4(A), the outer part 2, which is a press part, has a bending line 8 (ridge line) about several cm inside from the end face 7 along the end face 7 of a plate-shaped steel sheet having a curved part and a bent part (bending line 6). As shown in FIG. 4(B), the end of the outer part 2 of the present embodiment is provided with a bead 10 (concavo-convex part) recessed in an elliptical hemispherical shape.
[0016] The bead 10 is formed by recessing the end of the outer part 2 before flange formation into an elliptical hemispherical shape. Then, as shown in FIG. 4(C), the flange 11 is bent at about 90 degrees at the location of the bending line 8 to be formed on the outer part 2.
[0017] As shown in FIGS. 5 to 7, a plurality of beads 10 are arranged at appropriately set intervals Di (for example, a length of 10 [mm]) at the end of the outer part 2 before flange formation, that is, before bending the end. The bead 10 is provided in a range including the end face 7 of the curved or bent part of the outer part 2.
[0018] The bead 10 is formed by a recess 10a which is an arc formed by a part of an ellipsoid, and a flat portion 10b (convex portion) between adjacent recesses 10a. The recess 10a of the bead 10 is elliptical in shape, for example, on the end face 7 of the outer part 2, with a width Dw (e.g., width 8 [mm]) and a depth Dd (e.g., depth 0.6 [mm]). When viewed from above the outer part 2, the bead 10 may be semicircular, or it may be elliptical in shape, with a length in the extension direction of the end face 7 and a length in the perpendicular direction being different.
[0019] Furthermore, the boundary portion 10c between the recess 10a and the flat portion 10b of the bead 1 has a predetermined curvature R1 (for example, a radius of curvature of 0.1 [mm]) that is set as appropriate. Next, the method for forming the bead 10 will be explained using Figures 8 and 9. In the case of a pressed part equipped with a bead 10 at its end, such as the outer part 2 in this embodiment, the bead 10 is formed in conjunction with the shearing of the steel sheet Ps material by the press machine 20.
[0020] As shown in Figure 8, the press machine 20 has a die blade 21 for shearing the edge of the steel plate Ps. The die blade 21 has a recess 22 at its cutting edge that has the same shape as the bead 10. More specifically, multiple recesses 22 (see Figures 5-7), which are elliptical hemispherical indentations with the same shape as the bead 10, width Dw and depth Dd, are formed at intervals Di along the corner 21c between the upper surface 21a and the side surface 21b, which form the cutting edge of the die blade 21.
[0021] The steel plate Ps is placed on the upper surface 21a of the die blade 21, where the recess 22 is formed (Figure 9A). Next, a pad 23 with a flat lower side surface is placed on top of the steel plate Ps (Figure 9B). The steel plate Ps is pressed downwards (towards the die blade 21) by the pad 23 (Figure 9B). At this time, the lower side surface of the pad 23 and the side surface 21b of the die blade 21 are positioned to be approximately flush. In this state, the punch blade 24 moves along these sides from above (towards the pad 23) to below (towards the die blade 21) (Figure 9C). As a result, the punch blade 24 moves significantly downwards, beyond the upper surface 21a of the die blade 21 and exceeding the depth Dd of the recess 22.
[0022] As a result, the steel plate Ps is sheared along the side surface 21b of the die blade 21. At this time, the steel plate Ps is formed so that its end is recessed downward to match the shape of the recess 22 of the die blade 21 (Figure 9D). In this way, the steel plate Ps is sheared by the press machine 20, and simultaneously with the shearing, a bead 10 is formed at the end, becoming an outer part 2. By providing a bead 10 at the end of the steel plate Ps, even if the steel plate Ps is curved or bent, when the end is folded to form the flange 11, the stress generated in the flange 11 can be relieved and absorbed by the bead 10. This prevents unintended deformation of the area around the flange 11 of the outer part 2, which is a pressed part.
[0023] In this embodiment, when the pressed part is the outer part 2 of the bonnet 1, unintended deformation of the end of the outer part 2 is suppressed, allowing for precise flush alignment with the upper surface of the side body attached to the vehicle body adjacent to the bonnet 1. This improves the appearance of the vehicle body and reduces the man-hours required for alignment.
[0024] In particular, the outer part 2 has a bend line 8 of the flange 11 located at a curved or bent point when viewed from above (top view) of the outer part 2, so a large amount of stress acts on it when forming the flange 11. Therefore, by providing a bead 10 at the end of the outer part 2 of the bonnet 1, which is a press-formed part with such a complex shape, deformation of the outer part 2 can be effectively suppressed and the flange 11 can be provided at the end.
[0025] In this embodiment, the bead 10, which is an uneven portion provided at the end of the outer part 2, has a recess 10a having an arc portion that forms part of an ellipsoid, and the protrusions between the recesses 10a are flat portions 10b. By making the bead 10 hemispherical in this way, the die blade 21 is provided with recesses 22 corresponding to the recesses 10a, and the steel plate Ps is sheared by the press machine 20, making it easy to provide the bead 10 at the end of the pressed part which is the sheared steel plate Ps.
[0026] Furthermore, as shown in Figure 7, in the orthogonal view (viewed from C in Figure 5), which is the viewpoint when the flange 11 is viewed from a direction perpendicular to the thickness direction, the width Dw of the recess 10a is greater than the depth Dd of the recess 10a relative to the flat portion 10b. In this way, by making the bead 10 provided at the end of the outer part 2 horizontally elongated in the direction in which the end face 7 extends and making it shallow in depth, the formability when forming the bead 10 with the press machine 20 is improved compared to making the vertical cross-section a perfect semicircle.
[0027] Furthermore, since the boundary portion 10c between the recess 10 and the flat portion 10b has a predetermined curvature R1, stress concentration at the boundary portion 10c can be suppressed, and the strength of the boundary portion 10c of the outer part 2 can be improved. Furthermore, the outer part 2, which is a pressed part to which this disclosure applies, has a tensile strength of 270 [N / mm²], such as SPCC or SPHC. 2 ] or more and 340 [N / mm 2Since it is made of metal material below 340 [N / mm²], the bead 10 can be easily formed when shearing the steel plate Ps. 2 If the tensile strength of the steel plate Ps exceeds 270 [N / mm²], it is difficult to form the bead 10 when shearing the steel plate Ps. 2 If the value is less than ], even if a curved or bent steel plate Ps is bent to provide a flange 11, unintended deformation is unlikely to occur, and there is little need to apply this disclosure.
[0028] Furthermore, in this embodiment, the spacing Di of the beads 10 on the end face 7 of the outer part 2 is set appropriately, but the spacing Di may also be set to a value corresponding to the tensile strength of the steel plate Ps. For example, the higher the tensile strength of the steel plate Ps, the smaller the spacing Di of the beads 10 should be to make them denser. This makes it possible to properly provide the beads 10 in response to the ease (or difficulty) of deformation of the steel plate Ps, which differs with tensile strength.
[0029] The pressed part in this embodiment is the outer part 2 of the vehicle's hood 1, and the bending angle of the flange 11 is set to an angle close to 90 degrees (90 to 105 degrees). This prevents the flange 11 from getting in the way when assembling the inner part 3 into the outer part 2, and makes it easier to bend the flange 11 with a press machine, thereby improving the manufacturability of the hood 1.
[0030] The bending angle of the flange 11 can be set appropriately within a predetermined range near 90 degrees (for example, 90 to 105 degrees) depending on the application of the pressed part. This disclosure is not limited to the embodiments described above. For example, the detailed shape of the bead 10 may be different from that of this embodiment. In this embodiment, the bead 10 is elliptical hemispherical with a flat section 10b between the recesses 10a, but it may also be hemispherical, or the section between the recesses 10a may be convex.
[0031] Furthermore, this disclosure can be applied to various pressed parts of a vehicle body that have curved or bent sections, in addition to the hood. [Explanation of symbols]
[0032] 2. Outer parts (pressed parts) 8. Folding lines (ridge lines) 11 Flange 10. Bead (uneven part) 10a Recess (arc portion) 10b Flat section (convex section) 10c border
Claims
1. A pressed metal part for the outer body of a vehicle, having a curved or bent shape, wherein the end is bent along a ridge that includes the curved or bent portion to form a flange, The flange has an uneven surface formed along the direction in which it extends. A pressed part for a vehicle body characterized by the following features.
2. One of the recesses and protrusions that constitute the aforementioned uneven portion is formed as a flat portion. The other of the recess and the protrusion is formed as an arc portion that forms part of a sphere or ellipsoid. Pressed parts for the vehicle body as described in Feature 1.
3. In a perpendicular view of the flange as seen from a direction perpendicular to the thickness direction, the width of the arc portion is greater than the depth of the arc portion relative to the flat portion. Pressed parts for the vehicle body as described in Feature 2.
4. The boundary between the recess and the protrusion has a predetermined curvature when viewed in a perpendicular direction from a direction perpendicular to the thickness direction of the flange. Pressed parts for the vehicle body as described in Feature 2.
5. The aforementioned ridge is curved or bent when viewed from above in the top view of the pressed part of the vehicle body. Pressed parts for the vehicle body as described in Feature 1.
6. The aforementioned pressed part has a tensile strength of 270 [N / mm²]. 2 ] and 340 [N / mm 2 The following metal components are used: Pressed parts for the vehicle body as described in Feature 1.
7. The aforementioned uneven portions are formed at shorter intervals along the extending direction of the flange, with the higher the tensile strength of the material of the pressed part. Pressed parts for the vehicle body as described in commodity 6.
8. The bending angle of the flange is determined within a predetermined range near 90 degrees, according to the intended use of the pressed part. Pressed parts for the vehicle body as described in Feature 1.