Vehicle suspension structure and manufacturing method thereof

Abstract

[Problem] To improve the rigidity of a connecting section without using a separate component. [Solution] This structure for a vehicle suspension (an arm for a vehicle suspension) 11 comprises: a first plate 40 and a second plate 50; and a first connecting section 22 for connecting a component part 30 (a collar 31). The first plate has a flange section 48 that is bent with respect to a first flat plate section 42. The flange section of the first plate is stacked on, and joined to, a second body section 51 of the second plate. The first plate has an open section which faces the first flat plate section and which can be formed by press-working a first mounting surface 43 in a separate state in which the first flat plate section is bent. The second plate also has an open section facing a second flat plate section 52. The connecting section is formed by causing the first flat plate section of the first plate and the second flat plate section of the second plate to face each other at a distance and by arranging the first mounting surface and a second mounting surface 53 at a distance from each other.

Description

[Technical Field]

[0001] The present invention relates to a vehicle suspension structure and a method for manufacturing the same. [Background technology]

[0002] A vehicle suspension system has many components such as a vehicle suspension structure and a shock absorber. Examples of the vehicle suspension structure include a vehicle suspension arm and a vehicle suspension member. The vehicle suspension structure has a connecting portion that connects the vehicle suspension components.

[0003] As an arm for a vehicle suspension attached to the front of a vehicle, for example, a lower arm having a shape roughly resembling the letter λ in plan view is known (see Patent Document 1). This lower arm is a component of a double wishbone front suspension, and has a connecting portion where a collar is connected to each of the bifurcated arm ends by welding. The collar is a component part for the vehicle suspension, and connects the lower arm to the vehicle body so that it can swing. The connecting portion is formed by multiple wall portions. The connecting portion has a collar mating surface that corresponds to the shape of the outer peripheral surface of the collar. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 10,543,726 Summary of the Invention [Problem to be solved by the invention]

[0005] The connecting portion needs to have sufficient rigidity to withstand the force input from the tire via the ball joint. The portion forming the connecting portion is also subject to vehicle layout constraints. For this reason, it is difficult to make the cross-sectional shape of the connecting portion large, making it difficult to increase its rigidity. While it is possible to increase rigidity by increasing the thickness of the wall of the connecting portion, this would increase the weight of the part and manufacturing costs.

[0006] The lower arm disclosed in Patent Document 1 has a strut disposed near the connecting portion in order to increase the rigidity of the connecting portion.

[0007] However, this requires manufacturing the strut as a separate part from the main body of the lower arm, and welding the strut to the main body, which complicates the manufacturing process and increases manufacturing costs.

[0008] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a vehicle suspension structure that can increase the rigidity of a connecting portion without using a separate part, and a method for manufacturing the same. [Means for solving the problem]

[0009] One aspect of the present invention is a vehicle suspension structure having at least a first plate and a second plate that are press-formed, a main body portion, and a connecting portion for connecting a vehicle suspension component. The first plate has a first main body portion constituting the main body portion, a first flat plate portion continuous with a main surface of the first main body portion and bent relative to the main surface, a first mounting surface formed on the first flat plate portion and abutting against an outer surface of the component, and a flange portion continuous with the first flat plate portion, bent relative to the first flat plate portion, and extending outward beyond the main surface of the first main body portion. The second plate has a second main body portion constituting the main body portion together with the first main body portion of the first plate, a second flat plate portion continuous with the main surface of the second main body portion and bent relative to the main surface, and a second mounting surface formed on the second flat plate portion and abutting against the outer surface of the component. The first plate has an open portion facing the first flat plate portion so that the first mounting surface can be formed by press working when the first flat plate portion is bent as a single unit. The second plate has an open portion facing the second flat plate portion so that the second mounting surface can be formed by press working when the second flat plate portion is bent as a single unit. The main body portion is formed by bringing the first main body portion of the first plate and the second main body portion of the second plate face to face. The connecting portion is formed by bringing the first flat plate portion of the first plate and the second flat plate portion of the second plate face to face with a gap between them, and arranging the first mounting surface and the second mounting surface with a gap between them. The flange portion of the first plate is connected to the second main body portion of the second plate. so as to extend outward from the main surface of the second main body portion Overlapped and joined Here, the first main body portion of the first plate is joined to the second flat plate portion by being abutted against an end of the second flat plate portion of the second plate along a direction in which the flange portion is superimposed on the second main body portion of the second plate. The end of the second flat plate portion of the second plate is abutted against a side of the first main body portion of the first plate that faces the second main body portion. .

[0010] Another aspect of the present invention is a method for manufacturing a vehicle suspension structure having at least a first plate and a second plate that are press-formed products, a main body portion, and a connecting portion for connecting a component part of the vehicle suspension. The first plate is formed with a first main body portion constituting the main body portion, a first flat plate portion continuous with a main surface of the first main body portion and bent relative to the main surface, and a flange portion continuous with the first flat plate portion and bent relative to the first flat plate portion, extending outward from the main surface of the first main body portion. The first plate with the bent first flat plate portion is pressed against a die to form a first mounting surface on the first flat plate portion that abuts against the outer surface of the component. The second plate is formed with a second main body portion constituting the main body portion together with the first main body portion of the first plate, and a second flat plate portion continuous with the main surface of the second main body portion and bent relative to the main surface. The second plate, in which the second flat plate portion is bent, is brought into contact with the die and pressed, thereby forming a second mounting surface on the second flat plate portion that contacts the outer surface of the component. The first body portion of the first plate and the second body portion of the second plate are placed in a state where they face each other, the first flat plate portion of the first plate and the second flat plate portion of the second plate are placed facing each other with a gap between them, the first mounting surface and the second mounting surface are arranged with a gap between them, and the flange portion of the first plate is attached to the second body portion of the second plate. so as to extend outward from the main surface of the second main body portion In the overlapped state, the first plate and the second plate are integrated by welding to form the main body portion and the connecting portion. Here, the first main body portion of the first plate abuts against an end of the second flat plate portion of the second plate along a direction in which the flange portion is overlapped with the second main body portion of the second plate, and is welded to the second flat plate portion. The end of the second flat plate portion of the second plate abuts against a side of the first main body portion of the first plate that faces the second main body portion. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a vehicle suspension structure and a manufacturing method thereof that can increase the rigidity of a connecting portion without using a separate part. [Brief explanation of the drawings]

[0012] [Figure 1]1 is a perspective view showing a vehicle suspension arm as a vehicle suspension structure according to an embodiment, with vehicle suspension components attached thereto; [Figure 2] 1 is a perspective view showing the vehicle suspension arm with the first plate and the second plate spaced apart from each other; FIG. [Figure 3] FIG. 2 is a top view showing an arm for a vehicle suspension. [Figure 4] 4 is a view showing the connecting portion of the arm for a vehicle suspension as viewed from the direction indicated by the arrow 4 in FIG. 3. [Figure 5] FIG. 2 is a perspective view showing the vicinity of a connecting portion of the arm for a vehicle suspension. [Figure 6] 4 is an arrow view showing another connecting portion of the arm for a vehicle suspension as viewed from the direction indicated by the arrow 6 in FIG. 3. [Figure 7] FIG. 10 is a perspective view showing the vicinity of another connecting portion of the vehicle suspension arm. [Figure 8] FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 3. [Figure 9] FIG. 9 is a cross-sectional view taken along line 9-9 in FIG. 3. [Figure 10] 10A to 10C are views schematically showing a step of forming a flange portion on the first plate. [Figure 11] FIG. 3 is a cross-sectional view schematically showing a state in which a first plate is set in a metal mold die. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiments shown here are merely examples for embodying the technical concept of the present invention and are not intended to limit the present invention. Therefore, all other embodiments, examples, and operational techniques that can be conceived by those skilled in the art without departing from the spirit of the present invention are included within the scope and spirit of the present invention, as well as within the scope of the claims and their equivalents.

[0014] In addition, for the convenience of illustration and ease of understanding, the drawings attached to this specification may be represented schematically with the scale, aspect ratio, shape, etc. appropriately changed from the actual product, but these are merely examples and do not limit the interpretation of the present invention.

[0015] In this specification, ordinal numbers such as "first" and "second" may be used. However, unless otherwise specified, these ordinal numbers are used to identify components for the convenience of explanation and do not specify the number or order.

[0016] A vehicle suspension device has many components such as a vehicle suspension structure and a shock absorber. Examples of the vehicle suspension structure include a vehicle suspension arm and a vehicle suspension member. The vehicle suspension structure according to the present invention has at least a first plate and a second plate that are press-formed products, and has a main body and a connecting portion that connects components for the vehicle suspension. Examples of the vehicle suspension structure include a vehicle suspension arm and a vehicle suspension member. Below, an embodiment in which the vehicle suspension structure according to the present invention is applied to a vehicle suspension arm will be described.

[0017] (Embodiment) An embodiment of a vehicle suspension arm 11 will be described with reference to Figures 1 to 11. Figures 1 to 9 are diagrams used to explain the configuration of each part of the vehicle suspension arm 11 of the embodiment. Figures 10 and 11 are diagrams used to explain the processing of the first plate 40 of the vehicle suspension arm 11.

[0018] 1 to 3, a vehicle suspension arm 11 (hereinafter simply referred to as suspension arm 11) according to an embodiment is used as a lower arm, which is a component of a double wishbone front suspension provided on a vehicle such as an automobile. This suspension arm 11 is attached to the lower part at the front of the vehicle.

[0019] As shown in FIG. 3, the suspension arm 11 has an arm main body 20 (corresponding to the main body) that is generally λ-shaped in a plan view. A wheel support 21 is disposed at the end of the arm main body 20 shown on the upper side in FIG. 3. The wheel support 21 is swivellably connected to a wheel support member (neither of which is shown) via a ball joint. The arm main body 20 extends from the wheel support 21 so as to branch into two parts, left and right in FIG. 3. A first connecting part 22 (corresponding to the connecting part) that connects a vehicle suspension component 30 is disposed at the left end of the bifurcated arm in FIG. 3. A second connecting part 24 (corresponding to the other connecting part) that connects another vehicle suspension component 30 is disposed at the right end of the bifurcated arm in FIG. 3. The first connecting part 22 and the second connecting part 24 function as vehicle body connectors.

[0020] In the embodiment, the same component is used for the component 30 and the other component 30. Also, in the embodiment, the first connecting portion 22 and the second connecting portion 24 are configured in the same manner. For this reason, the members constituting the first connecting portion 22 and the members constituting the second connecting portion 24 are given the same reference numerals.

[0021] As shown in FIGS. 1 and 2, in this embodiment, the component 30 is, for example, a cylindrical member made of metal, and is generally referred to as a collar 31. The collar 31 has a hollow cylindrical shape, and a resin bushing (not shown) is press-fitted into the interior thereof. A connecting pin (not shown) is inserted through the center of the bushing. The axes of the collar 31, the bushing, and the connecting pin are aligned, for example, along the fore-and-aft direction of the vehicle body. The collar 31 connects the arm main body 20 to the vehicle body in a manner that allows it to swing.

[0022] As shown in Figures 1, 2, 4, 5, 6, 7, 8, and 9, the suspension arm 11 has at least a first plate 40 and a second plate 50, which are press-formed products. The illustrated suspension arm 11 is formed from two plates (the first plate 40 and the second plate 50). The first plate 40 is also referred to as the upper plate, and the second plate 50 is also referred to as the lower plate. The first plate 40 and the second plate 50 are generally λ-shaped in plan view. The suspension arm 11 has an arm main body 20 having a portion with a rectangular cross section (see Figure 9), and a first connecting portion 22 and a second connecting portion 24 that connect a vehicle suspension component 30.

[0023] 1, 2, 4, 5, 6, and 7, the first plate 40 has a first main body portion 41 constituting the arm main body 20, a first flat plate portion 42 that is continuous with a main surface 41a of the first main body portion 41 and is bent relative to the main surface 41a, and a first mounting surface 43 that is formed on the first flat plate portion 42 and abuts against the outer surface of the collar 31. The first plate 40 further has a flange portion 48 that is continuous with the first flat plate portion 42 and is bent relative to the first flat plate portion 42. The first flat plate portion 42 is bent from the main surface 41a of the first main body portion 41 toward the second plate 50. The flange portion 48 is bent so as to extend outward beyond the main surface 41a of the first main body portion 41.

[0024] Here, the "principal surface 41a of the first main body portion 41" refers to a portion that forms the main body of the first main body portion 41, and constitutes the upper portion of the arm main body portion 20 shown at the top in Figures 1 and 2. The "surface" in the term "principal surface 41a" does not distinguish between the front surface (the surface shown at the top in Figures 1 and 2) and the back surface. The principal surface 41a has a gently uneven shape and ensures the rigidity of the first main body portion 41. The folded first flat plate portion 42 constitutes part of the side of the arm main body portion 20. "Toward the outside of the principal surface 41a of the first main body portion 41" means, as shown in Figure 3, that it faces in a direction that extends outward from the principal surface 41a when viewed in a plan view from a direction intersecting the principal surface 41a of the first main body portion 41.

[0025] The second plate 50 has a second main body portion 51 that constitutes the arm main body portion 20 together with the first main body portion 41 of the first plate 40, a second flat plate portion 52 that is continuous with the main surface 51a of the second main body portion 51 and is bent and extends relative to the main surface 51a, and a second mounting surface 53 that is formed on the second flat plate portion 52 and abuts against the outer surface of the collar 31. The second flat plate portion 52 is bent from the main surface 51a of the second main body portion 51 toward the first plate 40.

[0026] Here, the "principal surface 51a of the second main body portion 51" refers to the main portion of the second main body portion 51, and constitutes the lower portion of the arm main body portion 20 shown on the lower side in FIG. 2. The "surface" in the term "principal surface 51a" does not distinguish between the front surface (the surface shown on the upper side in FIG. 2) and the back surface. The main surface 51a may have a gently uneven shape. The folded second flat plate portion 52 constitutes part of the side of the arm main body portion 20.

[0027] 2, 4, 5, 6, 7 and 11 described later, the first plate 40 has an open portion facing the first flat plate portion 42 so that the first mounting surface 43 can be formed by press working when the first flat plate portion 42 is folded as a single unit. Similarly, the second plate 50 has an open portion facing the second flat plate portion 52 so that the second mounting surface 53 can be formed by press working when the second flat plate portion 52 is folded as a single unit.

[0028] The arm main body 20 is configured by placing a first main body 41 of a first plate 40 and a second main body 51 of a second plate 50 facing each other.

[0029] The first connecting portion 22 and the second connecting portion 24 are constructed by placing the first flat portion 42 of the first plate 40 and the second flat portion 52 of the second plate 50 facing each other at a distance, and arranging the first mounting surface 43 and the second mounting surface 53 at a distance.

[0030] 4, 5, 6, 7, 8, and 9, the flange portion 48 of the first plate 40 is overlapped and joined to the second main body portion 51 of the second plate 50. The flange portion 48 is formed on the first flat plate portion 42 on which the first mounting surface 43 is formed. This increases the rigidity of the first flat plate portion 42, allowing the collar 31 to be firmly attached to the first mounting surface 43.

[0031] The first flat plate portion 42 has the first main body portion 41 disposed at one end (for example, the upper end in FIG. 8) along a direction intersecting the main surface 41a of the first main body portion 41, and a flange portion 48 disposed at the other end (for example, the lower end in FIG. 8). Therefore, even when the flange portion 48 is provided, the welding allowance between the first mounting surface 43 and the collar 31 is not interrupted, and a relatively long welding allowance can be ensured. This allows the collar 31 to be firmly attached to the first mounting surface 43.

[0032] 8, the first main body portion 41 of the first plate 40 is joined to the second flat plate portion 52 by abutting against the end portion 52a of the second flat plate portion 52 of the second plate 50 along the direction in which the flange portion 48 is overlapped with the second main body portion 51 of the second plate 50. The positions of the first plate 40 and the second plate 50 in the up-down direction in the figure during assembly are determined by abutting the first main body portion 41 against the end portion 52a of the second flat plate portion 52. This makes it easy to position the first plate 40 and the second plate 50, improving assembly efficiency.

[0033] Furthermore, the first plate 40 and the second plate 50 can be assembled simply by placing the first plate 40 on the second plate 50 from above. This allows for easy gap management between the first plate 40 and the second plate 50, improving weldability. The flange portion 48 and the second main body portion 51 of the first plate 40 and the second plate 50 can be welded from the bottom in the figure, and the first main body portion 41 and the second flat plate portion 52 can be welded from the bottom in the figure. There is no need to flip the positions of the first plate 40 and the second plate 50 or significantly change the position or posture of the welding machine. This improves weldability.

[0034] 2, 8, and 9, the portion of the first main body portion 41 that abuts against the end portion 52a of the second flat plate portion 52 is limited to a portion close to the second mounting surface 53 in order to increase the rigidity of the first connecting portion 22 and the second connecting portion 24. However, the entire end portion 52a of the second flat plate portion 52 may be configured to abut against the first main body portion 41.

[0035] The first plate 40 and the second plate 50 are joined together by fillet welds 76, 77 (see FIGS. 8 and 9). The reference numerals 76 and 77 of the fillet welds 76, 77 represent weld beads.

[0036] The angle formed between the first flat plate portion 42 and the main surface 41a of the first main body portion 41 is not particularly limited. As an example, as shown in Figures 4, 5, 6, 7, and 8, the first flat plate portion 42 can be bent to form an L-shape with respect to the main surface 41a of the first main body portion 41. Here, "bending to form an L-shape" means bending so that the cross-sectional shape of the first flat plate portion 42 and the main surface 41a has a substantially L-shape when viewed in a cross section perpendicular to the bending line between the first flat plate portion 42 and the first main body portion 41, as shown in Figure 8.

[0037] The angle formed between the flange portion 48 and the first flat plate portion 42 is not particularly limited. As an example, as shown in Figures 4, 5, 6, 7, and 8, the flange portion 48 can be bent to form an L-shape with respect to the first flat plate portion 42. Here, "bending to form an L-shape" means bending so that the cross-sectional shape of the flange portion 48 and the first flat plate portion 42 has a substantially L-shape when viewed in a cross section perpendicular to the bending line between the flange portion 48 and the first flat plate portion 42, as shown in Figure 8.

[0038] The angle formed between the second flat plate portion 52 and the main surface 51a of the second main body portion 51 is also not particularly limited. As an example, as shown in Figures 4, 5, 6, 7, and 8, the second flat plate portion 52 can be bent to form an L-shape with respect to the main surface 51a of the second main body portion 51. "Bending to form an L-shape" means bending so that the cross-sectional shape of the second flat plate portion 52 and the main surface 51a has a generally L-shape when viewed in a cross section perpendicular to the bending line between the second flat plate portion 52 and the second main body portion 51.

[0039] 3, the arm main body 20 has a curved portion 25 having an outline that curves from the location of the first connecting portion 22 toward the inside of the arm main body 20 when viewed in a plan view from a direction intersecting the main surface 41a of the first main body 41. The flange portion 48 is formed on the first flat plate portion 42 located at the curved portion 25. Therefore, the first plate 40 can increase the rigidity (bending rigidity) of the curved portion 25 extending from the location of the first connecting portion 22. In particular, the flange portion 48 can increase the rigidity (bending rigidity) of the curved portion 25 in the vicinity of the first connecting portion 22.

[0040] Here, "from the first connecting portion 22 toward the inside of the arm main body portion 20" means that, as shown in Figure 3, the contour of the arm main body portion 20 extends in a concave direction from the first connecting portion 22 (toward the upper side in Figure 3).

[0041] The suspension arm 11 of this embodiment includes, in addition to the first connecting portion 22 that connects the component 30 (collar 31), a second connecting portion 24 that connects another component 30 (collar 31). As shown in FIG. 3 , the arm main body 20 includes the curved portion 25, which has an outline that curves inward of the arm main body 20, between the first connecting portion 22 and the second connecting portion 24 when viewed in plan from a direction intersecting the main surface 41a of the first main body 41. The flange portion 48 is formed on the first flat plate portion 42 located at the curved portion 25. In this embodiment, the curved portion 25 forms a bifurcated portion that branches toward the first connecting portion 22 and the second connecting portion 24. Therefore, the first plate 40 can increase the rigidity (bending rigidity) of the curved portion 25 that extends between the first connecting portion 22 and the second connecting portion 24. In particular, the flange portion 48 can increase the rigidity (bending rigidity) of the curved portion 25 in the vicinity of the first connecting portion 22 and the rigidity (bending rigidity) in the vicinity of the second connecting portion 24.

[0042] As shown in Figures 4, 5, 6, and 7, the first mounting surface 43 is formed from a first end surface 44 formed at an end of the first flat plate portion 42, and the second mounting surface 53 is formed from a second end surface 54 formed at an end of the second flat plate portion 52. The collar 31 is attached to the first connecting portion 22 and the second connecting portion 24 by fillet welding to the first end surface 44 and the second end surface 54, respectively. With this configuration, the first mounting surface 43 and the second mounting surface 53 face outward, allowing the collar 31 to be easily attached by fillet welding.

[0043] As shown in FIGS. 2, 5, and 7, the first plate 40 further includes a first extension 45 that is continuous with the main surface 41a of the first main body 41 and extends outward from the first main body 41 beyond the first flat plate 42. The second plate 50 further includes a second extension 55 that is continuous with the main surface 51a of the second main body 51 and extends outward from the second main body 51 beyond the second flat plate 52. The first extension 45 and the second extension 55 can clamp the collar 31 from a direction (vertical direction in FIGS. 5 and 7) that intersects with the direction in which the first flat plate 42 and the second flat plate 52 face each other (approximately horizontal direction in FIGS. 5 and 7). The collar 31 is attached to the first connecting portion 22 and the second connecting portion 24 by fillet welding to the end faces of the first extension 45 and the second extension 55, respectively. As a result, the component 30 (collar 31) can be attached to the first connecting portion 22 and the second connecting portion 24 more firmly.

[0044] As shown in Figure 11, the first mounting surface 43 is formed by pressing the first plate 40, which is formed by bending the first flat plate portion 42, as a single piece. The pressing device may include, for example, a cam driver and a cam slider. The cam-type pressing process cuts out the first flat plate portion 42, allowing the first mounting surface 43 to be formed in accordance with the shape of the outer peripheral surface of the collar 31.

[0045] Similarly, the second mounting surface 53 is formed by pressing the second plate 50, which is a single piece formed by bending the second flat plate portion 52. The second flat plate portion 52 is cut out by cam-type pressing, and the second mounting surface 53 can be formed to correspond to the shape of the outer peripheral surface of the collar 31.

[0046] As shown in FIG. 11 , when forming the first mounting surface 43, the first plate 40, with the first flat plate portion 42 and the flange portion 48 bent, is pressed against a metal mold die 60 (corresponding to a die). The width W of the metal mold die 60 is set to a width sufficient to ensure strength sufficient to withstand the load during press processing. The portion of the first plate 40 where the first flat plate portion 42 and the first extension portion 45 are formed has a substantially L-shaped cross section, and the portion facing the first flat plate portion 42 is open. The first plate 40 is positioned with the first extension portion 45 in contact with the top surface of the metal mold die 60 and the first flat plate portion 42 in contact with the side surface of the metal mold die 60. In this state, the first plate 40 is pressed by a punch 63, removing a portion of the first flat plate portion 42 and forming the first mounting surface 43. The metal mold die 60 has a space 60a into which the tip of the punch 63 can enter. The space 60a communicates with a chute (not shown) that discharges scraps scraped off by the punch 63.

[0047] Similarly, when forming the second mounting surface 53, the second plate 50 with the bent second flat plate portion 52 is pressed against the metal mold die 60. The portion of the second plate 50 where the second flat plate portion 52 and the second extension portion 55 are formed has a substantially L-shaped cross section, and the portion facing the second flat plate portion 52 is open. The second plate 50 is positioned with the second extension portion 55 in contact with the top surface of the metal mold die 60 and the second flat plate portion 52 in contact with the side surface of the metal mold die 60. In this state, the second plate 50 is pressed by a punch 63, which removes a portion of the second flat plate portion 52 and forms the second mounting surface 53.

[0048] The axial length of the collar 31 may be set relatively short due to constraints such as vehicle body layout. In such cases, the width of the first extension portion 45 may be smaller than the width of the molding die 60. Even in such cases, the cross section of the portion that abuts against the molding die 60 is generally L-shaped, allowing the first flat plate portion 42 and the first extension portion 45 to abut against the molding die 60 and forming the first mounting surface 43 without hindrance. Similarly, even when the width of the second extension portion 55 is smaller than the width of the molding die 60, the cross section of the portion that abuts against the molding die 60 is generally L-shaped, allowing the second flat plate portion 52 and the second extension portion 55 to abut against the molding die 60 and forming the second mounting surface 53 without hindrance. Therefore, there is no need to form the first mounting surface 43 and the second mounting surface 53 using a laser cutting device or the like instead of press working, which reduces manufacturing costs.

[0049] As described above, the area of ​​the first plate 40 where the first flat portion 42 and the first extension portion 45 are formed has a generally L-shaped cross section, allowing the first mounting surface 43 to be formed without any hindrance. Therefore, as shown in FIGS. 4, 5, 6, and 7, the flange portion 48 can be formed as close as possible to the base of the first mounting surface 43. This improves the rigidity of the area near the base of the first mounting surface 43 without increasing the plate thickness or reinforcing it with a separate part. As a result, the collar 31 can be firmly attached to the first mounting surface 43.

[0050] The manufacturing procedure for the suspension arm 11 will now be described.

[0051] The suspension arm 11 has a first plate 40 and a second plate 50, an arm main body 20, and a first connecting portion 22 and a second connecting portion 24 to which a collar 31 is attached.

[0052] First, on the first plate 40, a first main body portion 41 constituting the arm main body portion 20, a first flat plate portion 42 continuous with the main surface 41a of the first main body portion 41 and bent relative to the main surface 41a to extend therefrom, and a flange portion 48 continuous with the first flat plate portion 42 and bent relative to the first flat plate portion 42 to extend outward beyond the main surface 41a of the first main body portion 41 are formed.

[0053] As shown schematically in FIG. 10 , first, a blank material 49 is press-formed using dies 61a and 61b to draw the blank material 49. As a result, the blank material 49 is formed into the first main body portion 41, the first flat plate portion 42, and a bent portion 49a that is continuous with the first flat plate portion 42 and bent relative to the first flat plate portion 42. The bent portion 49a forms the bottom plate portion. Thereafter, the blank material 49 is press-formed using dies 62a and 62b to trim unnecessary portions of the bent portion 49a. As a result, the first main body portion 41, the first flat plate portion 42, and the flange portion 48 are formed in the first plate 40.

[0054] The first plate 40 with the bent first flat portion 42 is pressed against a metal mold die 60 to form a first mounting surface 43 on the first flat portion 42 that abuts against the outer surface of the collar 31.

[0055] Similarly, the second plate 50 is formed with a second main body portion 51 that forms the arm main body portion 20 together with the first main body portion 41, and a second flat plate portion 52 that is continuous with the main surface 51a of the second main body portion 51 and is bent and extends relative to the main surface 51a.

[0056] The second plate 50 with the bent second flat plate portion 52 is pressed against a die, whereby a second mounting surface 53 that comes into contact with the outer surface of the collar 31 is formed on the second flat plate portion 52 .

[0057] Then, the first main body portion 41 of the first plate 40 and the second main body portion 51 of the second plate 50 are brought into a state where they face each other. Furthermore, the first flat plate portion 42 of the first plate 40 and the second flat plate portion 52 of the second plate 50 are brought into a state where they face each other with a gap between them, and the first mounting surface 43 and the second mounting surface 53 are arranged with a gap between them. Furthermore, the flange portion 48 of the first plate 40 is brought into a state where it overlaps the second main body portion 51 of the second plate 50. In this state, the first plate 40 and the second plate 50 are integrated by welding to form the arm main body portion 20, the first connecting portion 22, and the second connecting portion 24.

[0058] During assembly, the first main body portion 41 of the first plate 40 abuts against the end portion 52a of the second flat plate portion 52 of the second plate 50 along the direction in which the flange portion 48 is overlapped with the second main body portion 51 of the second plate 50. In this state, the first main body portion 41 is welded to the second flat plate portion 52.

[0059] As described above, the suspension arm 11 of the embodiment has the first plate 40 and the second plate 50, which are press-formed products, and has the arm main body 20 and the first connecting portion 22 that connects the vehicle suspension component 30 (collar 31). The first plate 40 has a first main body 41 that constitutes the arm main body 20, a first flat plate portion 42 that is continuous with the main surface 41 a of the first main body 41 and is bent relative to the main surface 41 a to extend therefrom, a first mounting surface 43 that is formed on the first flat plate portion 42 and abuts against the outer surface of the component 30 (collar 31), and a flange portion 48 that is continuous with the first flat plate portion 42 and is bent relative to the first flat plate portion 42 to extend outward beyond the main surface 41 a of the first main body 41. The second plate 50 has a second main body portion 51 that constitutes the arm main body portion 20 together with the first main body portion 41 of the first plate 40, a second flat plate portion 52 that is continuous with the main surface 51a of the second main body portion 51 and is bent and extends relative to the main surface 51a, and a second mounting surface 53 that is formed on the second flat plate portion 52 and abuts against the outer surface of the component 30 (collar 31). The first plate 40 has an open portion facing the first flat plate portion 42 so that the first mounting surface 43 can be formed by press working when the first flat plate portion 42 is in a single folded state. The second plate 50 has an open portion facing the second flat plate portion 52 so that the second mounting surface 53 can be formed by press working when the second flat plate portion 52 is in a single folded state. The arm main body portion 20 is formed by placing the first main body portion 41 of the first plate 40 and the second main body portion 51 of the second plate 50 facing each other. The first connecting portion 22 is configured by arranging the first flat plate portion 42 of the first plate 40 and the second flat plate portion 52 of the second plate 50 facing each other with a gap therebetween, and by arranging the first mounting surface 43 and the second mounting surface 53 with a gap therebetween. The flange portion 48 of the first plate 40 is overlapped and joined to the second main body portion 51 of the second plate 50.

[0060] In the suspension arm 11 configured in this manner, the flange portion 48 is formed on the first flat plate portion 42 on which the first mounting surface 43 is formed. This increases the rigidity of the first flat plate portion 42, allowing the component 30 (collar 31) to be firmly attached to the first mounting surface 43. The location where the flange portion 48 is formed is not subject to the vehicle layout restrictions. Therefore, the size and position of the flange portion 48 can be determined without being subject to the vehicle layout restrictions. This facilitates design to increase the rigidity of the first connecting portion 22. Furthermore, the rigidity of the first connecting portion 22 can be increased without manufacturing or welding a separate part (for example, the strut described in Patent Document 1). Furthermore, even if the axial length of the component 30 (collar 31) is set to be relatively short due to constraints such as vehicle layout, the cross section of the portion including the first flat plate portion 42 and the second flat plate portion 52 has a substantially L-shape, so the first mounting surface 43 and the second mounting surface 53 can be formed without difficulty by press-forming the first plate 40 and the second plate 50 individually. Therefore, there is no need to form the first mounting surface 43 and the second mounting surface 53 using a laser cutting device or the like instead of press-forming, and increases in manufacturing costs can be suppressed. Therefore, it is possible to provide a suspension arm 11 that increases the rigidity of the first connecting portion 22 without using a separate part, and further, that can form the first connecting portion 22 for attaching the component 30 (collar 31) by applying cost-effective press-forming even when the axial length of the component 30 (collar 31) is short.

[0061] The first main body portion 41 of the first plate 40 is joined to the second flat plate portion 52 by being abutted against the end portion 52a of the second flat plate portion 52 of the second plate 50 along the direction in which the flange portion 48 is overlapped with the second main body portion 51 of the second plate 50. This configuration makes it easy to position the first plate 40 and the second plate 50, improving assembly efficiency.

[0062] The first flat plate portion 42 is bent to form an L shape relative to the main surface 41a of the first main body portion 41, the flange portion 48 is bent to form an L shape relative to the first flat plate portion 42, and the second flat plate portion 52 is bent to form an L shape relative to the main surface 51a of the second main body portion 51. With this configuration, the pressing process is not complicated because the portions are bent to form an L shape.

[0063] The arm main body 20 has a curved portion 25 having an outline that curves from the location of the first connecting portion 22 toward the inside of the arm main body 20 when viewed in a plan view from a direction intersecting the main surface 41a of the first main body 41. The flange portion 48 is formed on the first flat plate portion 42 located at the curved portion 25. With this configuration, the first plate 40 can increase the rigidity (bending rigidity) of the curved portion 25 extending from the location of the first connecting portion 22. In particular, the flange portion 48 can increase the rigidity (bending rigidity) of the curved portion 25 in the vicinity of the first connecting portion 22.

[0064] The suspension arm 11 of this embodiment further includes a second connecting portion 24 that connects another vehicle suspension component 30 (collar 31). The arm main body 20 includes a curved portion 25, which has an outline that curves inward of the arm main body 20, between the first connecting portion 22 and the second connecting portion 24, when viewed from above in a direction intersecting the main surface 41a of the first main body 41. The flange portion 48 is formed on the first flat plate portion 42 located at the curved portion 25. This configuration of the first plate 40 increases the rigidity (bending rigidity) of the curved portion 25 extending between the first connecting portion 22 and the second connecting portion 24. In particular, the flange portion 48 can increase the rigidity (bending rigidity) of the curved portion 25 near the first connecting portion 22 and the second connecting portion 24. Therefore, the lateral rigidity of the arm portion that is bifurcated into left and right parts with the curved portion 25 sandwiched therebetween can be improved without using a strut, which is a separate component.

[0065] The suspension arm 11 manufactured by the manufacturing method of the embodiment includes a first plate 40 and a second plate 50, which are press-formed products, and an arm main body 20 and a first connecting portion 22 to which a vehicle suspension component 30 (collar 31) is attached. To manufacture the suspension arm 11, first, a first main body 41, a first flat plate 42, and a flange 48 are formed in the first plate 40. The first plate 40, with the first flat plate 42 bent, is brought into contact with a mold die 60 and pressed to form a first mounting surface 43. Similarly, a second main body 51 and a second flat plate 52 are formed in the second plate 50. The second plate 50, with the second flat plate 52 bent, is brought into contact with the mold die 60 and pressed to form a second mounting surface 53. The first main body 41 of the first plate 40 and the second main body 51 of the second plate 50 are then placed face to face. The first flat plate portion 42 of the first plate 40 and the second flat plate portion 52 of the second plate 50 are placed opposite each other with a gap between them, and the first mounting surface 43 and the second mounting surface 53 are also placed with a gap between them. Furthermore, with the flange portion 48 of the first plate 40 overlapping the second main body portion 51 of the second plate 50, the first plate 40 and the second plate 50 are integrated by welding to form the arm main body portion 20 and the first connecting portion 22.

[0066] According to the manufacturing method configured in this manner, it is possible to provide a suspension arm 11 in which the rigidity of the first connecting portion 22 can be increased without using a separate part, and further, even when the axial length of the component 30 (collar 31) is short, the first connecting portion 22 to which the component 30 (collar 31) is attached can be formed by applying cost-effective press processing.

[0067] The first main body portion 41 of the first plate 40 is welded to the second flat plate portion 52 by abutting against the end 52a of the second flat plate portion 52 of the second plate 50 along the direction in which the flange portion 48 is overlapped with the second main body portion 51 of the second plate 50. Manufacturing in this manner facilitates positioning between the first plate 40 and the second plate 50, improving assembly efficiency. Furthermore, it is easy to manage the gap between the first plate 40 and the second plate 50, improving weldability. Moreover, the welding of the flange portion 48 to the second main body portion 51 and the welding of the first main body portion 41 to the second flat plate portion 52 can be performed from the same side. This further improves weldability.

[0068] The first plate 40 is formed by drawing a blank 49 to form a first main body portion 41, a first flat plate portion 42, and a bent portion 49a that is continuous with the first flat plate portion 42 and is bent relative to the first flat plate portion 42, and then trimming an unnecessary portion of the bent portion 49a to form a flange portion 48. By manufacturing in this manner, the thickness of the bent portion 49a, including the portion that will eventually become the flange portion 48, is fixed when the drawing is completed. Therefore, cracks can be prevented from occurring at the end of the flange portion 48 compared to a procedure in which the flange portion 48 is further bent and formed after the first flat plate portion 42 is formed.

[0069] The first flat plate portion 42 is bent to form an L shape relative to the main surface 41a of the first main body portion 41, the flange portion 48 is bent to form an L shape relative to the first flat plate portion 42, and the second flat plate portion 52 is bent to form an L shape relative to the main surface 51a of the second main body portion 51. By manufacturing in this manner, the pressing process is not complicated because the portions are bent to form an L shape.

[0070] The arm main body 20 has a curved portion 25 formed thereon, which has an outline that curves from the location of the first connecting portion 22 toward the inside of the arm main body 20, when viewed in a plan view from a direction intersecting the main surface 41a of the first main body 41. The flange portion 48 is formed on the first flat plate portion 42 located at the curved portion 25. By manufacturing the first plate 40 in this manner, the rigidity (bending rigidity) of the curved portion 25 extending from the location of the first connecting portion 22 can be increased. In particular, the flange portion 48 can increase the rigidity (bending rigidity) of the curved portion 25 in the vicinity of the first connecting portion 22.

[0071] The suspension arm 11 of this embodiment further includes a second connecting portion 24 that connects another vehicle suspension component 30 (collar 31). The arm main body 20 includes a curved portion 25, which has an outline that curves inward of the arm main body 20, between the first connecting portion 22 and the second connecting portion 24, when viewed from above in a direction intersecting the main surface 41a of the first main body 41. The flange portion 48 is formed on the first flat plate portion 42 located at the curved portion 25. This manufacturing process of the first plate 40 increases the rigidity (bending rigidity) of the curved portion 25 extending between the first connecting portion 22 and the second connecting portion 24. In particular, the flange portion 48 can increase the rigidity (bending rigidity) of the curved portion 25 near the first connecting portion 22 and the second connecting portion 24. Therefore, the lateral rigidity of the bifurcated arm portion, which is bifurcated with the curved portion 25 sandwiched between them, can be improved without using a strut, which is a separate component.

[0072] (Variation) The present invention is not limited to the above-described embodiment and can be modified as appropriate. For example, although the vehicle suspension arm 11 formed from two plates (the first plate 40 and the second plate 50) has been shown, it can be formed from three or more plates.

[0073] Although the suspension arm 11 has been described in which the second connecting portion 24 (another connecting portion) has the same structure as the first connecting portion 22 (connecting portion), the present invention is not limited to this case. The present invention can also be applied to a vehicle suspension structure in which the structure of the second connecting portion 24 differs from the structure of the first connecting portion 22.

[0074] Although the suspension arm 11 has been described as having the second connecting portion 24 in addition to the first connecting portion 22, the present invention is not limited to this case. The present invention can also be applied to a vehicle suspension structure that has only the first connecting portion 22 and does not have the second connecting portion 24.

[0075] In the embodiment, the vehicle suspension structure according to the present invention is applied to a vehicle suspension arm, but the present invention is not limited to this case. The vehicle suspension structure according to the present invention can be applied to a vehicle suspension member as long as it has a first plate and a second plate that are press-formed products, a main body, and a connecting portion that connects components of the vehicle suspension. [Explanation of symbols]

[0076] 11 Suspension arms (vehicle suspension structures, vehicle suspension arms), 20 arm body (body), 21 wheel support; 22 1st connection part (connection part), 24 second connection (other connection), 25 curved section, 30 Components for vehicle suspensions; 31 colors, 40 First Plate, 41 first body part, 41a: a main surface of the first main body portion; 42 1st flat plate part, 43 first mounting surface, 44 first end surface, 45 1st extension; 48 flange portion, 49 blanks, 49a bend, 50 Second Plate, 51 second body part, 51a: a main surface of the second main body portion; 52 2nd flat plate part, 52a end of the second flat plate portion; 53 second mounting surface, 54 second end surface, 55 Second extension, 60 mold dies, 63 punches.

Claims

1. A vehicle suspension structure having at least a first plate and a second plate which are press-formed products, a main body portion, and a connecting portion for connecting components for the vehicle suspension, the first plate has a first main body portion constituting the main body portion, a first flat plate portion continuous with a main surface of the first main body portion and bent relative to the main surface to extend therefrom, a first mounting surface formed on the first flat plate portion and abutting against an outer surface of the component, and a flange portion continuous with the first flat plate portion, bent relative to the first flat plate portion to extend outward beyond the main surface of the first main body portion, the second plate has a second main body portion constituting the main body portion together with the first main body portion of the first plate, a second flat plate portion continuous with a main surface of the second main body portion and bent and extending relative to the main surface, and a second mounting surface formed on the second flat plate portion and abutting against the outer surface of the component, the first plate has an open portion facing the first flat plate portion so that the first mounting surface can be formed by press working when the first flat plate portion is bent as a single unit; the second plate has an open portion facing the second flat plate portion so that the second mounting surface can be formed by press working when the second flat plate portion is bent as a single unit; the main body portion is configured by placing the first main body portion of the first plate and the second main body portion of the second plate opposite each other, the connecting portion is configured by arranging the first flat plate portion of the first plate and the second flat plate portion of the second plate opposite each other with a gap therebetween, and by arranging the first mounting surface and the second mounting surface with a gap therebetween, the flange portion of the first plate is overlapped and joined to the second main body portion of the second plate so as to extend outward from the main surface of the second main body portion, Here, the first main body portion of the first plate is abutted against an end of the second flat plate portion of the second plate along a direction in which the flange portion is overlapped with the second main body portion of the second plate, and joined to the second flat plate portion, A vehicle suspension structure, wherein the end of the second flat plate portion of the second plate abuts against the side of the first main body portion of the first plate that faces the second main body portion.

2. the first flat plate portion is bent to form an L-shape with respect to the main surface of the first main body portion, The flange portion is bent relative to the first flat plate portion to form an L-shape, 2. The vehicle suspension structure according to claim 1, wherein the second flat plate portion is bent to form an L-shape with respect to the main surface of the second main body portion.

3. the main body portion has a curved portion having a contour that curves from the connecting portion toward an inner side of the main body portion when viewed in a plan view from a direction intersecting a main surface of the first main body portion, 2. The vehicle suspension structure according to claim 1, wherein the flange portion is formed on the first flat plate portion located at the curved portion.

4. Further, the suspension system has other connecting portions for connecting other components for the vehicle suspension; the main body portion has a curved portion between the connecting portion and the other connecting portion, the curved portion having a contour curved toward the inside of the main body portion when seen in a plan view from a direction intersecting with the main surface of the first main body portion, 2. The vehicle suspension structure according to claim 1, wherein the flange portion is formed on the first flat plate portion located at the curved portion.

5. The vehicle suspension structure according to any one of claims 1 to 4, which is applied to a vehicle suspension arm.

6. A method for manufacturing a vehicle suspension structure having at least a first plate and a second plate which are press-formed products, a main body portion, and a connecting portion for connecting components for the vehicle suspension, the method comprising: The first plate is formed with a first main body portion constituting the main body portion, a first flat plate portion continuous with a main surface of the first main body portion and bent relative to the main surface to extend therefrom, and a flange portion continuous with the first flat plate portion, bent relative to the first flat plate portion, and extending outward beyond the main surface of the first main body portion; the first plate, in which the first flat plate portion is bent, is brought into contact with a die and pressed, thereby forming a first mounting surface on the first flat plate portion that comes into contact with an outer surface of the component; The second plate is formed with a second body portion that configures the body portion together with the first body portion of the first plate, and a second flat plate portion that is continuous with a main surface of the second body portion and is bent and extends relative to the main surface, the second plate, in which the second flat plate portion is bent, is brought into contact with the die and pressed, thereby forming a second mounting surface on the second flat plate portion that comes into contact with the outer surface of the component; the first body portion of the first plate and the second body portion of the second plate are placed opposite each other, the first flat plate portion of the first plate and the second flat plate portion of the second plate are placed opposite each other with a gap between them, the first mounting surface and the second mounting surface are arranged with a gap between them, and the flange portion of the first plate is overlapped with the second body portion of the second plate so as to extend outward from the main surface of the second body portion, and the first plate and the second plate are integrated by welding to form the body portion and the connecting portion; Here, the first main body portion of the first plate is abutted against an end of the second flat plate portion of the second plate along a direction in which the flange portion is overlapped with the second main body portion of the second plate, and is welded to the second flat plate portion, A method for manufacturing a vehicle suspension structure, wherein the end of the second flat plate portion of the second plate is abutted against the side of the first main body portion of the first plate facing the second main body portion.

7. the first plate is formed by drawing a blank material to have the first main body portion, the first flat plate portion, and a bent portion that is continuous with the first flat plate portion and bent relative to the first flat plate portion; 7. The method for manufacturing a vehicle suspension structure according to claim 6, wherein the flange portion is then formed by trimming an unnecessary portion of the bent portion.

8. the first flat plate portion is bent to form an L-shape with respect to the main surface of the first main body portion; the flange portion is bent relative to the first flat plate portion to form an L-shape, The method for manufacturing a vehicle suspension structure according to claim 6, wherein the second flat plate portion is bent to form an L-shape with respect to the main surface of the second main body portion.

9. When viewed in a plan view from a direction intersecting the main surface of the first main body portion, a curved portion having a contour curved from the connecting portion toward an inner side of the main body portion is formed, 7. The method for manufacturing a vehicle suspension structure according to claim 6, wherein the flange portion is formed on the first flat plate portion located at the curved portion.

10. The vehicle suspension structure further includes other connecting portions for connecting other components for the vehicle suspension; When viewed in a plan view from a direction intersecting a main surface of the first main body portion, a curved portion having a contour curved toward an inward side of the main body portion is formed between the connecting portion and the other connecting portion, 7. The method for manufacturing a vehicle suspension structure according to claim 6, wherein the flange portion is formed on the first flat plate portion located at the curved portion.

11. The method for manufacturing a vehicle suspension structure according to any one of claims 6 to 10, which is applied to an arm for a vehicle suspension.

Images