METHOD FOR MANUFACTURING PRESS-FORMED PRODUCT

Abstract

A method for manufacturing a press-formed product, the method including press forming a first formed product from a blank material, press forming a second formed product from the first formed product, and press forming the press-formed product from the second formed product. The press-formed product is a member extending in its longitudinal direction, and includes a top plate and two vertical walls. The first formed product includes a preliminary top plate, an inclined section, and a flat section. The second formed product includes a preliminary top plate, an inclined section, and a preliminary vertical wall. The preliminary vertical wall is formed by deforming the flat section while the preliminary top plate and the inclined section in the first formed product are held between dies.

Claims

1. A method for manufacturing a press-formed product, the method comprising: forming a first formed product by press forming a plate-shaped blank material; forming a second formed product by press forming the first formed product; and forming the press-formed product by press forming the second formed product, the press-formed product being a member extending in its longitudinal direction, the press-formed product comprising: a top plate that is an elongated plate-shaped portion extending in the longitudinal direction; and two vertical walls that are wall-like portions protruding on a first side from opposite ends of the top plate in a width direction of the top plate, the first formed product being a member extending in the longitudinal direction, the first formed product including: a preliminary top plate that is an elongated plate-shaped portion extending in the longitudinal direction; an inclined section that is a plate-shaped portion extending in a curved manner on the first side from a first end of the preliminary top plate in a width direction of the preliminary top plate; and a flat section that is a plate-shaped portion extending from an end of the inclined section opposite the preliminary top plate, the second formed product being a member extending in the longitudinal direction, the second formed product including: the preliminary top plate; the inclined section; and a preliminary vertical wall that is a wall-like portion protruding on the first side from the end of the inclined section opposite the preliminary top plate, the preliminary vertical wall being formed by deforming the flat section while the preliminary top plate and the inclined section in the first formed product are held between dies.

2. The method according to claim 1, wherein the first formed product is formed by holding the blank material between a first die disposed on the first side and a second die disposed on a second side opposite the first side, and the preliminary vertical wall is formed by pressing the flat section from the second side with a third die disposed on the second side while the preliminary top plate and the inclined section in the first formed product are held between the first die and the second die.

3. The method according to claim 1, wherein the press-formed product is formed by pressing and deforming the inclined section with a sixth die disposed on the first side while the preliminary top plate in the second formed product is held between a fourth die disposed on a second side opposite the first side and a fifth die disposed on the first side.

4. The method according to claim 3, wherein the inclined section and the preliminary vertical wall contact the fourth die and the sixth die when the press-formed product is formed by press forming the second formed product.

5. The method according to claim 4, wherein the second formed product includes a flange that is a plate-shaped portion bulging from an end of the preliminary vertical wall opposite the inclined section, the flange in the second formed product corresponds to part of the flat section in the first formed product, the flange in the second formed product contacts the fourth die and the sixth die when the press-formed product is formed by press forming the second formed product.

6. The method according to claim 1, wherein press forming for forming the first formed product, the second formed product, and the press-formed product is performed by displacing the dies along a first direction, the press-formed product includes a first top plate end that is located in the width direction of the top plate and corresponds to part of the inclined section in the second formed product, a distance in the first direction between an end of the preliminary top plate on the inclined section side and an end of the preliminary vertical wall opposite the inclined section, in a first cross section of the second formed product orthogonal to the longitudinal direction, is defined as a first distance, a distance in the first direction between the first top plate end and an end of one of the two vertical walls protruding from the first top plate end, in a cross section of the press-formed product orthogonal to the longitudinal direction corresponding to the first cross section, is defined as a second distance, and the first distance and the second distance are approximately same.

7. The method according to claim 1, wherein the top plate includes a curved section that is a curved area that bulges out toward the first side in a cross section along the longitudinal direction, and the second formed product includes the inclined section in part of the press-formed product corresponding to the curved section.

8. The method according to claim 1, wherein the press-formed product is made from high-tensile steel having a tensile strength of 980 MPa or more.

9. The method according to claim 1, wherein the press-formed product is installed on a vehicle.

10. The method according to claim 9, wherein the press-formed product forms part of a vehicle body.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] An example embodiment of the present disclosure will be described hereinafter with reference to the accompanying drawings, in which:

[0028] FIG. 1 is a perspective view of a press-formed product;

[0029] FIG. 2 is a side view showing an end of the press-formed product in its width direction;

[0030] FIG. 3 is a top view of the press-formed product;

[0031] FIG. 4 is a side view showing an end of the press-formed product in its longitudinal direction;

[0032] FIG. 5 is an explanatory diagram showing the press forming machine when a first process is started;

[0033] FIG. 6 is an explanatory diagram showing the press forming machine when the first process is completed;

[0034] FIG. 7 is an explanatory diagram showing the press forming machine during press forming in a second process;

[0035] FIG. 8 is an explanatory diagram showing the press forming machine when the second process is completed;

[0036] FIG. 9 is an explanatory diagram showing the press forming machine when a third process is started; and

[0037] FIG. 10 an explanatory diagram showing the press forming machine when the third process is completed.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

1. First Embodiment

[1-1. Press-Formed Product]

[0038] A press-formed product 1 of the first embodiment is formed by press forming a metal material (see FIG. 1). In the first embodiment, high-tensile steel having a tensile strength of 980 MPa or more is used as the metal material. However, the metal material is not limited to this. The metal material may be, for example, high-tensile steel having a tensile strength of 1470 MPa or more, may be high-tensile steel having a tensile strength less than 980 MPa, or may be stainless steel or iron.

[0039] In addition, the press-formed product 1 is used as a member that forms part of a vehicle body, as an example. However, the press-formed product 1 is not limited to this. The press-formed product 1 may be used as a member that forms a part other than a vehicle body, or may be used as a member not installed on a vehicle.

[0040] The press-formed product 1 is a plate-shaped member, and comprises a top plate 12, a vertical wall 13, a flange 14, an opposing vertical wall 15, and an opposing flange 16 (see FIGS. 1 to 4).

[0041] The press-formed product 1 is a groove-shaped member, and extends from a first end 10 to a second end 11 along its longitudinal direction. The press-formed product 1 also has a curved shape so that the first end 10 and the second end 11 protrude toward a second side D2, that is, with a center area of the press-formed product 1 bulging out toward a first side D1 in a cross section along the longitudinal direction (see FIG. 2). The first side D1 is a side on which the flange 14 and the opposing flange 16 are located relative to the top plate 12, and the second side D2 is opposite the first side D1. Of course, the shape of the press-formed product 1 is not limited to this. The press-formed product 1 may have a straight-lined shape in the cross section along the longitudinal direction.

[0042] The top plate 12 is an elongated plate-shaped portion extending from the first end 10 to the second end 11 along the longitudinal direction. The press-formed product 1 has a longer length in its width direction (hereinafter, simply referred to as width direction) from a center area of the top plate 12 in the longitudinal direction toward the second end 11. The top plate 12 includes a curved section 120.

[0043] The curved section 120 is a plate-shaped portion located in a curved area that bulges out toward the first side D1 in the cross section along the longitudinal direction of the top plate 12. The curved section 120 is located substantially in the center of the top plate 12 in the longitudinal direction.

[0044] The vertical wall 13 is a plate-shaped portion protruding on the first side D1 from one end of the top plate 12 in the width direction (hereinafter, referred to as first top plate end 17), and extends from the first end 10 to the second end 11 of the top plate 12. The vertical wall 13 includes an upper vertical wall 130, a first stepped section 131, a second stepped section 132, and a lower vertical wall 133.

[0045] The upper vertical wall 130 is a wall-like portion protruding on the first side D1 from the first top plate end 17.

[0046] The first stepped section 131 and the second stepped section 132 are step-shaped portions that are located at an end of the upper vertical wall 130 opposite the top plate 12 and protrude opposite the opposing vertical wall 15. The first stepped section 131 and the second stepped section 132 are aligned in the longitudinal direction. The first stepped section 131 is located on the first end 10 side, and the second stepped section 132 is located on the second end 11 side. In addition, the first stepped section 131 has an approximately triangular shape when viewed from the second side D2 (see FIG. 3). An end portion forming one side of the first stepped section 131 extends along an end portion of the upper vertical wall 130. The vertical wall 13 does not have to have the first stepped section 131 and the second stepped section 132. In other words, the vertical wall 13 may be, for example, a wall-like portion that protrudes straight out on the first side D1 from the first top plate end 17 without bending.

[0047] The lower vertical wall 133 is a wall-like portion that protrudes on the first side D1 from ends of the first stepped section 131 and the second stepped section 132 opposite the opposing vertical wall 15.

[0048] The flange 14 is a plate-shaped portion protruding opposite the opposing vertical wall 15 from an end of the lower vertical wall 133 opposite the first stepped section 131 and the second stepped section 132.

[0049] The opposing vertical wall 15 is a plate-shaped portion that protrudes on the first side D1 from an end of the top plate 12 opposite the first top plate end 17. The opposing vertical wall 15 faces the vertical wall 13 in the width direction. The opposing vertical wall 15 may include a step-shaped portion like the first stepped section 131 and the second stepped section 132 of the vertical wall 13.

[0050] In a cross section orthogonal to the longitudinal direction of the press-formed product 1, a length of the opposing vertical wall 15 protruding on the first side D1 is preferably less than or equal to a length of the vertical wall 13 protruding on the first side D1, and more preferably less than the length of the vertical wall 13 protruding on the first side D1.

[0051] The opposing flange 16 is a plate-shaped portion protruding opposite the vertical wall 13 from an end of the opposing vertical wall 15 opposite the top plate 12.

[1-2. Method for Manufacturing Press-Formed Product]

[0052] The method for manufacturing the press-formed product 1 comprises a first process, a second process, and a third process. In the first process, a first formed product 5 is formed by press forming a blank material B (see FIGS. 5 and 6). In the second process, a second formed product 6 is formed by press forming the first formed product 5 (see FIGS. 7 and 8). In the third process, the press-formed product 1 is formed by press forming the second formed product 6 (see FIGS. 9 and 10).

[1-3. Press Forming Machine in First Process]

[0053] In the first process, the first formed product 5 is formed by press forming the plate-shaped blank material B, which is made from the above-described metal material and extends along the longitudinal direction, using a press forming machine (see FIG. 5).

[0054] The press forming machine in the first process comprises a first lower die 2, an upper pad 3, and a first upper die 4, which are dies for press forming.

[0055] The first lower die 2 is located below the blank material B. The first lower die 2 extends along the longitudinal direction and protrudes on the upper side in a cross section orthogonal to the longitudinal direction (hereinafter, simply referred to as cross section). The first lower die 2 includes a preliminary top plate shaper 20, an inclination shaper 21, a preliminary vertical wall shaper 22, a flange shaper 23, an opposing vertical wall shaper 24, and an opposing flange shaper 25.

[0056] The preliminary top plate shaper 20 is a shaping surface that extends along the longitudinal direction and forms a top surface of a portion of the first lower die 2 protruding on the upper side.

[0057] The inclination shaper 21 is a shaping surface extending downward in a curved manner from one end of the preliminary top plate shaper 20 in the width direction.

[0058] The preliminary vertical wall shaper 22 is a shaping surface extending downward from an end of the inclination shaper 21 opposite the preliminary top plate shaper 20. The preliminary vertical wall shaper 22 has a smaller angle relative to an up-down direction in press forming than the inclination shaper 21.

[0059] The flange shaper 23 is a shaping surface extending opposite the opposing vertical wall shaper 24 from an end of the preliminary vertical wall shaper 22 opposite the inclination shaper 21.

[0060] The opposing vertical wall shaper 24 is a shaping surface extending downward from an end of the preliminary top plate shaper 20 opposite the inclination shaper 21.

[0061] The opposing flange shaper 25 is a shaping surface extending opposite the flange shaper 23 from an end of the opposing vertical wall shaper 24 opposite the preliminary top plate shaper 20. The opposing flange shaper 25 is located on an upper side compared to the flange shaper 23.

[0062] The upper pad 3 extends along the longitudinal direction, and is located above the blank material B. The upper pad 3 is supported by a gas spring from above, and is displaceable in the up-down direction. The upper pad 3 is disposed to face the first lower die 2 in the up-down direction. The upper pad 3 comprises a preliminary top plate shaper 30 and an inclination shaper 31.

[0063] The preliminary top plate shaper 30 is an elongated shaping surface extending along the longitudinal direction in the upper pad 3. The preliminary top plate shaper 30 faces the preliminary top plate shaper 20 of the first lower die 2 in the up-down direction.

[0064] The inclination shaper 31 is a shaping surface extending downward in a curved manner from an end of the preliminary top plate shaper 30 in the width direction on the preliminary vertical wall shaper 22 side in the first lower die 2. The inclination shaper 31 faces the inclination shaper 21 of the first lower die 2 in the up-down direction.

[0065] The first upper die 4 extends in the longitudinal direction, and is located above the blank material B. The first upper die 4 is disposed to face the first lower die 2 in the up-down direction, and is displaceable in the up-down direction. The first upper die 4 includes a preliminary vertical wall shaper 40, a flange shaper 41, an opposing vertical wall shaper 42, and an opposing flange shaper 43.

[0066] The preliminary vertical wall shaper 40 is a shaping surface extending upward from an end of the flange shaper 41 in the width direction on the upper pad 3 side. The preliminary vertical wall shaper 40 faces the preliminary vertical wall shaper 22 of the first lower die 2 in the up-down direction.

[0067] The flange shaper 41 is a shaping surface located in a lower part of the first upper die 4. The flange shaper 41 is located on the inclination shaper 31 side of the upper pad 3 in the width direction, and faces the flange shaper 23 of the first lower die 2 in the up-down direction.

[0068] The opposing vertical wall shaper 42 is a shaping surface extending upward from an end of the opposing flange shaper 43 in the width direction on the upper pad 3 side. The opposing vertical wall shaper 42 faces the opposing vertical wall shaper 24 of the first lower die 2 in the up-down direction.

[0069] The opposing flange shaper 43 is a shaping surface located in a lower portion of the first upper die 4. The opposing flange shaper 43 is located on the preliminary top plate shaper 30 side of the upper pad 3 in the width direction, and faces the opposing flange shaper 25 of the first lower die 2 in the up-down direction.

[1-4. First Process]

[0070] In the first process, the blank material B is disposed between the first lower die 2 and the upper pad 3 (see FIG. 5). Then, by displacing the upper pad 3 downward, the blank material B is held between the first lower die 2 and the upper pad 3 (see FIG. 6).

[0071] At this time, an upper surface of the blank material B contacts the preliminary top plate shaper 30 and the inclination shaper 31 of the upper pad 3, and a lower surface of the blank material B contacts the preliminary top plate shaper 20 and the inclination shaper 21 of the first lower die 2. In addition, the blank material B is deformed along the preliminary top plate shaper 30 and the inclination shaper 31 by receiving pressure from the first lower die 2 and the upper pad 3. As a result, a preliminary top plate 50 and an inclined section 51 are formed from the blank material B.

[0072] The above process forms the first formed product 5 from the blank material B.

[1-5. First Formed Product]

[0073] The first formed product 5 is a plate-shaped member extending along the longitudinal direction, and comprises the preliminary top plate 50, the inclined section 51, a flat section 52, and an opposing flat section 53 (see FIG. 6).

[0074] The preliminary top plate 50 is an elongated plate-shaped portion extending along the longitudinal direction.

[0075] The inclined section 51 is a plate-shaped portion extending downward (in other words, on the first side D1) in a curved manner from one end of the preliminary top plate 50 in the width direction.

[0076] The flat section 52 is a plate-shaped portion extending from an end of the inclined section 51 opposite the preliminary top plate 50.

[0077] The opposing flat section 53 is a plate-shaped portion extending from an end of the preliminary top plate 50 opposite the inclined section 51.

[1-6. Second Process]

[0078] In the second process, while the first formed product 5 formed in the first process is held between the first lower die 2 and the upper pad 3, the first upper die 4 is displaced downward to press the flat section 52 and the opposing flat section 53 (see FIG. 7).

[0079] When the first upper die 4 is displaced downward, an upper surface of the flat section 52 contacts the preliminary vertical wall shaper 40 and the flange shaper 41 of the first upper die 4, and a lower surface of the flat section 52 contact the preliminary vertical wall shaper 22 and the flange shaper 23 of the first lower die 2.

[0080] The flat section 52 is deformed along the preliminary vertical wall shaper 40 and the flange shaper 41 by receiving pressure from the first lower die 2 and the first upper die 4. As a result, a preliminary vertical wall 62 and a flange 63 are formed from the flat section 52 (see FIG. 8).

[0081] When the first upper die 4 is displaced downward, an upper surface of the opposing flat section 53 contacts the opposing vertical wall shaper 42 and the opposing flange shaper 43 of the first upper die 4, and a lower surface of the opposing flat section 53 contacts the opposing vertical wall shaper 24 and the opposing flange shaper 25 of the first lower die 2.

[0082] In addition, the opposing flat section 53 is deformed along the opposing vertical wall shaper 42 and the opposing flange shaper 43 by receiving pressure from the first lower die 2 and the first upper die 4. As a result, an opposing vertical wall 64 and an opposing flange 65 are formed from the opposing flat section 53.

[0083] The above process forms the second formed product 6 from the first formed product 5.

[1-7. Second Formed Product]

[0084] The second formed product 6 is a plate-shaped member extending in the longitudinal direction, and comprises a preliminary top plate 60, an inclined section 61, the preliminary vertical wall 62, the flange 63, the opposing vertical wall 64, and the opposing flange 65 (see FIG. 8).

[0085] The preliminary top plate 60 is an elongated plate-shaped portion extending along the longitudinal direction.

[0086] The inclined section 61 is a plate-shaped portion extending downward in a curved manner from one end of the preliminary top plate 60 in the width direction. In the second process, the inclined section 61 may have an angle of 40 or more and less than 90 relative to the up-down direction in press forming, as an example.

[0087] The preliminary vertical wall 62 is a plate-shaped portion protruding downward from an end of the inclined section 61 opposite the preliminary top plate 60.

[0088] The flange 63 is a plate-shaped portion protruding opposite the opposing vertical wall 64 from an end of the preliminary vertical wall 62 opposite the inclined section 61.

[0089] The opposing vertical wall 64 is a plate-shaped portion protruding downward from an end of the preliminary top plate 60 opposite the inclined section 61. The opposing vertical wall 64 faces the preliminary vertical wall 62 in the width direction.

[0090] The opposing flange 65 is a plate-shaped portion protruding opposite the preliminary vertical wall 62 from an end of the opposing vertical wall 64 opposite the preliminary top plate 60.

[0091] The preliminary top plate 60 and the inclined section 61 of the second formed product 6 correspond to the preliminary top plate 50 and the inclined section 51 of the first formed product 5. The opposing vertical wall 64 and the opposing flange 65 correspond to the opposing vertical wall 15 and the opposing flange 16 of the press-formed product 1.

[1-8. Press Forming Machine in Third Process]

[0092] In the third process, the press-formed product 1 is formed by press forming the second formed product 6 using a press forming machine.

[0093] The press forming machine in the third process comprises a second upper die 7, a lower pad 8, and a second lower die 9, which are dies for press forming (see FIG. 9).

[0094] The second upper die 7 is located above the second formed product 6, and is displaceable in the up-down direction. The second upper die 7 extends along the longitudinal direction, and has a cross-sectional shape with its lower surface being recessed on the upper side. The second upper die 7 includes a top plate shaper 70, a vertical wall shaper 71, a flange contactor 72, an opposing vertical wall contactor 73, and an opposing flange contactor 74.

[0095] The top plate shaper 70 is a shaping surface that extends along the longitudinal direction and forms a bottom surface of a portion of the second upper die 7 recessed on the upper side.

[0096] The vertical wall shaper 71 is a shaping surface extending downward from one end of the top plate shaper 70 in the width direction.

[0097] The flange contactor 72 is a shaping surface extending opposite the opposing vertical wall contactor 73 from an end of the vertical wall shaper 71 opposite the top plate shaper 70.

[0098] The opposing vertical wall contactor 73 is a shaping surface extending downward from an end of the top plate shaper 70 opposite the vertical wall shaper 71.

[0099] The opposing flange contactor 74 is a shaping surface extending opposite the vertical wall shaper 71 from an end of the opposing vertical wall contactor 73 opposite the top plate shaper 70. The opposing flange contactor 74 is located on an upper side compared to the flange contactor 72.

[0100] The lower pad 8 extends along the longitudinal direction, and has a cross-sectional shape with its upper surface protruding on the upper side. The lower pad 8 is supported by a gas spring from below, and is displaceable in the up-down direction. The lower pad 8 is located below the second formed product 6, and is disposed to face the second upper die 7. The lower pad 8 comprises a preliminary top plate contactor 80, an opposing vertical wall contactor 81, and an opposing flange contactor 82.

[0101] The preliminary top plate contactor 80 is a shaping surface that extends along the longitudinal direction and forms a top surface of a portion of the lower pad 8 protruding on the upper side. The preliminary top plate contactor 80 faces the top plate shaper 70 of the second upper die 7 in the up-down direction.

[0102] The opposing vertical wall contactor 81 is a shaping surface extending downward from and end of the preliminary top plate contactor 80 in the width direction opposite the second lower die 9. The opposing vertical wall contactor 81 faces the opposing vertical wall contactor 73 of the second upper die 7 in the up-down direction.

[0103] The opposing flange contactor 82 is a shaping surface extending opposite the second lower die 9 from an end of the opposing vertical wall contactor 81 opposite the preliminary top plate contactor 80. The opposing flange contactor 82 faces the opposing flange contactor 74 of the second upper die 7 in the up-down direction.

[0104] The second lower die 9 extends along the longitudinal direction and has a cross-sectional shape with its upper surface protruding on the upper side. The second lower die 9 is located below the second formed product 6 and is disposed to face the second upper die 7. The second lower die 9 comprises a top plate shaper 90, a vertical wall shaper 91, and a flange contactor 92.

[0105] The top plate shaper 90 is a shaping surface that extends along the longitudinal direction and forms a top surface of a portion of the second lower die 9 protruding on the upper side. The top plate shaper 90 faces the top plate shaper 70 of the second upper die 7 in the up-down direction.

[0106] The vertical wall shaper 91 is a shaping surface extending downward from an end of the top plate shaper 90 opposite the lower pad 8. The vertical wall shaper 91 faces the vertical wall shaper 71 of the second upper die 7 in the up-down direction.

[0107] The flange contactor 92 is a shaping surface extending opposite the lower pad 8 from an end of the vertical wall shaper 91 opposite the top plate shaper 90. The flange contactor 92 faces the flange contactor 72 of the second upper die 7 in the up-down direction.

[1-9. Third Process]

[0108] In the third process, the second formed product 6 is disposed between the second upper die 7 and the lower pad 8. Then, the second formed product 6 is held between the second upper die 7 and the lower pad 8 (see FIG. 9).

[0109] At this time, the preliminary top plate 60 in the second formed product 6 contacts the top plate shaper 70 of the second upper die 7 and the preliminary top plate contactor 80 of the lower pad 8, and the opposing vertical wall 64 contacts the opposing vertical wall contactor 73 of the second upper die 7 and the opposing vertical wall contactor 81 of the lower pad 8. The opposing flange 65 contacts the opposing flange contactor 74 of the second upper die 7 and the opposing flange contactor 82 of the lower pad 8. Also, an upper surface of the preliminary vertical wall 62 contacts the vertical wall shaper 71 of the second upper die 7, and an upper surface of the flange 63 contacts the flange contactor 72 of the second upper die 7. On the other hand, there is a gap between the inclined section 61, and the top plate shaper 70 and the vertical wall shaper 71.

[0110] Then, by displacing the second formed product 6 held between the second upper die 7 and the lower pad 8 downward, the inclined section 61 is pressed with the second lower die 9 (see FIG. 10).

[0111] When the inclined section 61 is pressed with the second lower die 9, an upper surface of the inclined section 61 contacts the top plate shaper 70 and the vertical wall shaper 71 of the second upper die 7, and a lower surface of the inclined section 61 contacts the top plate shaper 90 and the vertical wall shaper 91 of the second lower die 9. Also, the upper surface of the preliminary vertical wall 62 contacts the vertical wall shaper 71, a lower surface of the preliminary vertical wall 62 contacts the vertical wall shaper 91, the upper surface of the flange 63 contacts the flange contactor 72, and a lower surface of the flange 63 contacts the flange contactor 92.

[0112] Then, the inclined section 61 is deformed along the top plate shaper 70 and the vertical wall shaper 71 by receiving pressure from the second upper die 7 and the second lower die 9. With this deformation, material flows from the flange 63 to the preliminary vertical wall 62.

[0113] As a result, the top plate 12 and the vertical wall 13 are formed from the preliminary top plate 60, the inclined section 61, and the preliminary vertical wall 62.

[0114] The above process forms the press-formed product 1 from the second formed product 6.

[0115] A distance in the up-down direction between an end of the preliminary top plate 60 on the inclined section 61 side and an end of the preliminary vertical wall 62 opposite the inclined section 61 in a first cross section of the second formed product 6 is defined as a first distance L1 (see FIG. 8). A distance in the up-down direction between the first top plate end 17 and an end of the vertical wall 13 on the flange 14 side in a cross section corresponding to a first cross section of the press-formed product 1 is defined as a second distance L2 (see FIG. 10). The cross section corresponding to the first cross section of the press-formed product 1 is a cross section that is located at the same position in the longitudinal direction as the first cross section of the second formed product 6.

[0116] At this time, the first distance L1 and the second distance L2 are approximately equal no matter which position in the entire longitudinal direction is taken as the first cross section. In other words, in the third process, when the press-formed product 1 is formed from the second formed product 6, the height in the up-down direction generally does not change.

[1-10. Effect]

[0117] According to the embodiment detailed above, the following effects can be obtained.

[0118] (1) When the press-formed product 1 is formed from the blank material B by a single press forming, it is conceivable to press form the top plate 12 to form the vertical wall 13 while the top plate 12 is held by the dies in order to limit material flow in the top plate 12 and inhibit formation of cracks and wrinkles. However, according to this method, sufficient pressure cannot be applied to the vertical wall 13, and wrinkles may be formed on the vertical wall 13. Particularly, wrinkles may be formed in part of the vertical wall 13 near the top plate 12.

[0119] In contrast, in the above-described method, the flat section 52 is deformed to form the preliminary vertical wall 62 while the preliminary top plate 50 and the inclined section 51 of the first formed product 5 is held between the upper pad 3 and the first lower die 2 in the second process.

[0120] Accordingly, upon the press forming in the second process, it is possible to limit material flow in the preliminary top plate 50 and the inclined section 51, and inhibit wrinkles from being formed in the preliminary top plate 50 and the inclined section 51 of the second formed product 6.

[0121] (2) When the press-formed product 1 is formed from the blank material B by a single press forming, the vertical wall 13 with high height in the up-down direction is formed by a single press forming. Thus, the amount of material flowing during the press forming is increased, which may cause wrinkles in the vertical wall 13.

[0122] In contrast, in the above-described method, the preliminary vertical wall 62 of the second formed product 6 formed in the second process has lower height in the up-down direction than the vertical wall 13. Thus, the amount of material flowing during a single press forming is small.

[0123] Accordingly, upon the press forming in the second process, it is possible to inhibit wrinkles from being formed in the preliminary vertical wall 62 of the second formed product 6.

[0124] (3) In the method of the above-described embodiment, the first formed product 5 is formed by holding the blank material B between the first lower die 2 and the upper pad 3 in the first process. Thereafter, by pressing the flat section 52 with the first upper die 4 while the first formed product 5 is held between the first lower die 2 and the upper pad 3, the second formed product 6 is formed.

[0125] With the configuration as above, it is possible to appropriately form the preliminary top plate 60, the inclined section 61, and the preliminary vertical wall 62 of the second formed product 6.

[0126] (4) In the above-described method, the preliminary top plate 60, the opposing vertical wall 64 and the opposing flange 65 of the second formed product 6 are held between the second upper die 7 and the lower pad 8 in the third process. Then, by pressing the inclined section 61 with the second lower die 9 to be deformed while the second formed product 6 is held, the press-formed product 1 is formed.

[0127] Thus, during the press forming in the third process, it is possible to limit material flow in the preliminary top plate 60, the opposing vertical wall 64 and the opposing flange 65 of the second formed product 6, and inhibit wrinkles from being formed in the top plate 12, the opposing vertical wall 15 and the opposing flange 16 of the press-formed product 1.

[0128] (5) In the method of the above-described embodiment, during the press forming in the third process, the inclined section 61, the preliminary vertical wall 62 and the flange 63 of the second formed product 6 are brought into contact with the second upper die 7 and the second lower die 9.

[0129] With the configuration as above, it is possible to limit excessive material flow during the press forming in the third process, and inhibit wrinkles from being formed in the press-formed product 1.

[0130] (6) In the method of the above-described embodiment, the inclined section 61 of the second formed product 6 includes a ridge line extending along the longitudinal direction at both ends in the width direction. This allows increased rigidity around the inclined section 61 of the second formed product 6.

[0131] Thus, it is possible to inhibit buckling around the inclined section 61 and inhibit wrinkles from being formed in the press-formed product 1 during the press forming in the third process.

[0132] (7) The press-formed product 1 in the above-described embodiment has a curved shape in the cross section along the longitudinal direction. Thus, if the press-formed product 1 is formed from the blank material B by a single press forming, material tends to flow into the area of the vertical wall 13 near the curved section 120 during the press forming, and wrinkles are likely to be formed.

[0133] In contrast, in the above-described method, the second formed product 6 includes the inclined section 61 in part of the press-formed product 1 corresponding to the curved section 120.

[0134] Thus, it is possible to inhibit wrinkles from being formed in the area of the vertical wall 13 near the curved section 120 in the press-formed product 1.

[1-11. Correspondence Between Terms]

[0135] In the above-described embodiment, the first lower die 2 corresponds to an example of a first die, the upper pad 3 corresponds to an example of a second die, the first upper die 4 corresponds to an example of a third die, the second upper die 7 corresponds to an example of a fourth die, the lower pad 8 corresponds to an example of a fifth die, and the second lower die 9 corresponds to an example of a sixth die. Also, the vertical wall 13 and the opposing vertical wall 15 correspond to an example of two vertical walls. The up-down direction corresponds to an example of a first direction.

2. Other Embodiments

[0136] (1) In the above-described embodiment, the second formed product 6 includes the inclined section 61 over its entire length in the longitudinal direction. However, the second formed product 6 is not limited to this. The second formed product 6 may include the inclined section 61 in part of the longitudinal direction. For example, the second formed product 6 may include the inclined section 61 only in part of the press-formed product 1 corresponding to the curved section 120.

[0137] In the above-described embodiment, the second formed product 6 includes the inclined section 61 at one end of the preliminary top plate 60 in the width direction. However, the second formed product 6 is not limited to this. The second formed product 6 may include the inclined section 61 at both ends of the preliminary top plate 60 in the width direction.

[0138] (2) In the above-described embodiment, the inclined section 61 in the second formed product 6 extends straight in the cross section. However, the inclined section 61 is not limited to this. For example, the inclined section 61 may be bent in the cross section, or may extend in a gently curved manner.

[0139] (3) In the above-described embodiment, each die used in each process is formed as a single piece. However, each die is not limited to this, and may include two or more dies. For example, the upper pad 3 may include a die including the preliminary top plate shaper 30, and a die including the inclination shaper 31.

[0140] (4) In the above-described embodiment in the method for manufacturing the press-formed product 1, the first process, the second process, and the third process are performed successively, and no separate processing is performed between the processes. However, the method for manufacturing the press-formed product 1 is not limited to these processes, and other processes may be performed between each process.

[0141] (5) Two or more functions achieved by one element of the above-described embodiments may be achieved by two or more elements. One function achieved by one element may be achieved by two or more elements. Two or more functions achieved by two or more elements may be achieved by one element. One function achieved by two or more elements may be achieved by one element. Part of the configurations in the above-described embodiments may be omitted. At least part of the configurations in one of the above-described embodiments may be added to or replaced with the configuration in another one of the above-described embodiments.

3. Technical Idea Disclosed in Present Specification

[Item 1]

[0142] A method for manufacturing a press-formed product, the method comprising: [0143] forming a first formed product by press forming a plate-shaped blank material; [0144] forming a second formed product by press forming the first formed product; and [0145] forming the press-formed product by press forming the second formed product, [0146] the press-formed product being a member extending in its longitudinal direction, the press-formed product comprising: [0147] a top plate that is an elongated plate-shaped portion extending in the longitudinal direction; and [0148] two vertical walls that are wall-like portions protruding on a first side from opposite ends of the top plate in a width direction of the top plate, [0149] the first formed product being a member extending in the longitudinal direction, the first formed product including: [0150] a preliminary top plate that is an elongated plate-shaped portion extending in the longitudinal direction; [0151] an inclined section that is a plate-shaped portion extending in a curved manner on the first side from a first end of the preliminary top plate in a width direction of the preliminary top plate; and [0152] a flat section that is a plate-shaped portion extending from an end of the inclined section opposite the preliminary top plate, [0153] the second formed product being a member extending in the longitudinal direction, the second formed product including: [0154] the preliminary top plate; [0155] the inclined section; and [0156] a preliminary vertical wall that is a wall-like portion protruding on the first side from the end of the inclined section opposite the preliminary top plate, [0157] the preliminary vertical wall being formed by deforming the flat section while the preliminary top plate and the inclined section in the first formed product are held between dies.

[Item 2]

[0158] The method according to Item 1, wherein [0159] the first formed product is formed by holding the blank material between a first die disposed on the first side and a second die disposed on a second side opposite the first side, and [0160] the preliminary vertical wall is formed by pressing the flat section from the second side with a third die disposed on the second side while the preliminary top plate and the inclined section in the first formed product are held between the first die and the second die.

[Item 3]

[0161] The method according to Item 1 or 2, wherein [0162] the press-formed product is formed by pressing and deforming the inclined section with a sixth die disposed on the first side while the preliminary top plate in the second formed product is held between a fourth die disposed on a second side opposite the first side and a fifth die disposed on the first side.

[Item 4]

[0163] The method according to Item 3, wherein [0164] the inclined section and the preliminary vertical wall contact the fourth die and the sixth die when the press-formed product is formed by press forming the second formed product.

[Item 5]

[0165] The method according to Item 4, wherein [0166] the second formed product includes a flange that is a plate-shaped portion bulging from an end of the preliminary vertical wall opposite the inclined section, [0167] the flange in the second formed product corresponds to part of the flat section in the first formed product, [0168] the flange in the second formed product contacts the fourth die and the sixth die when the press-formed product is formed by press forming the second formed product.

[Item 6]

[0169] The method according to any one of Items 1 to 5, wherein [0170] press forming for forming the first formed product, the second formed product, and the press-formed product is performed by displacing the dies along a first direction, [0171] the press-formed product includes a first top plate end that is located in the width direction of the top plate and corresponds to part of the inclined section in the second formed product, [0172] a distance in the first direction between an end of the preliminary top plate on the inclined section side and an end of the preliminary vertical wall opposite the inclined section, in a first cross section of the second formed product orthogonal to the longitudinal direction, is defined as a first distance, [0173] a distance in the first direction between the first top plate end and an end of one of the two vertical walls protruding from the first top plate end, in a cross section of the press-formed product orthogonal to the longitudinal direction corresponding to the first cross section, is defined as a second distance, and [0174] the first distance and the second distance are approximately same.

[Item 7]

[0175] The method according to any one of Items 1 to 6, wherein [0176] the top plate includes a curved section that is a curved area that bulges out toward the first side in a cross section along the longitudinal direction, and [0177] the second formed product includes the inclined section in part of the press-formed product corresponding to the curved section.