JP7244287B2 - Press molded product - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to a press-formed product formed using a material in which different steel plates are joined together.

In order to improve collision safety and reduce the weight of automobiles, press-formed products made from a plurality of steel plates joined together by a tailored method or the like are used. Patent Literature 1 proposes a side sill structure using tailored blank members that are joined so that the plate thickness differs in the longitudinal direction of the vehicle body.

JP 2012-148590 A

In the side sill structure disclosed in Patent Document 1, considering safety in a full-wrap frontal collision or an offset frontal collision, the plate thickness is the thickest at the front side of the vehicle, and the plate thickness decreases toward the rear side. However, in order to improve safety against side collisions, it is desirable to increase the plate thickness in the entire front-rear direction. However, increasing the plate thickness of the rear portion of the side sill structure increases the weight of the entire side sill structure.

An object of the present disclosure is to propose a technique capable of improving strength in multiple directions while suppressing an increase in weight.

One aspect of the present disclosure is a press-formed product, and the press-formed product is made of a material in which a plurality of different steel plates are joined together. This press-formed product has a length in a first direction and includes three plate-like portions connected via at least two bent portions arranged side by side in a second direction intersecting the first direction. A protruding portion having a convex cross-sectional shape is provided. A joint portion where two steel plates are joined among the plurality of steel plates is positioned along the first direction.

With such a configuration, a plurality of different steel plates, for example, steel plates with relatively high strength and steel plates with relatively light weight, are arranged over a wide range in the first direction. As a result, the press-formed product has a higher strength in the first direction, a higher strength in a direction crossing the first direction, and a lighter weight as a whole.

In the press-formed product described above, the joint portion may be located in a region other than the bent portion of the press-formed product. With such a configuration, since there is no joining portion at least in the bent portion, the strength of the bent portion is less likely to vary, and the quality of the press-formed product can be stabilized.

The press-formed product described above may be a side sill that is arranged below a door that is arranged on the side of a vehicle and that is arranged such that the predetermined direction is the longitudinal direction of the vehicle. With such a configuration, the strength of the vehicle in the front-rear direction and the left-right direction can be increased by the side sills, the safety against frontal collision and side collision can be improved, and the weight of the vehicle can be reduced. .

The press-formed product described above may include a first steel plate and a second steel plate. The second steel plate may be a steel plate that is relatively thinner than the first steel plate. The first steel plate may be positioned above the second steel plate when mounted on the vehicle.

With such a configuration, the strength of the upper side of the side sill of the vehicle is increased. From the viewpoint of the strength of the vehicle body structure, it is preferable that the strength of the upper side of the side sill is high.

FIG. 1A is a perspective view of the press-molded product of the embodiment, and FIG. 1B is a cross-sectional view of the press-molded product. It is a side view which shows a part of structure of a vehicle body. It is a figure explaining the manufacturing process of the press-formed article of embodiment. It is a figure explaining the process of manufacturing a blank material from a tailored material. It is a typical side view explaining the process of press working. It is a typical side view explaining the process of press working. It is a cross-sectional view of a press-formed product of a modification.

Embodiments of the present disclosure will be described below with reference to the drawings. Note that the vertical, horizontal, and front/rear directions used in the following description are used for convenience of description, and do not limit the mode of use of the present disclosure.

[1. embodiment]
[1-1. Configuration of press-molded product]
As shown in FIGS. 1A and 1B, the press-formed product 1 includes a first plate-like portion 11, a second plate-like portion 12, a third plate-like portion 13, a first flange 14, and a second flange 15. . The first plate-shaped portion 11 and the second plate-shaped portion 12 are connected via the first bent portion 16, and the second plate-shaped portion 12 and the third plate-shaped portion 13 are connected via the second bent portion 17. be done. The first bent portion 16 and the second bent portion 17 have a length in the front-rear direction and are arranged side by side in the vertical direction.

The front-back direction described above corresponds to the first direction, and the up-down direction described above corresponds to the second direction. Also, the first bent portion 16 and the second bent portion 17 correspond to bent portions, and the first plate-like portion 11, the second plate-like portion 12, and the third plate-like portion 13 correspond to plate-like portions. Hereinafter, when referring to both the first bent portion 16 and the second bent portion 17, they are simply referred to as a bent portion. In addition, the bent portion in the present embodiment refers to a portion bent by the bending process when a plate-shaped workpiece is bent by pressing.

Such a press-formed product 1 is an elongated member whose longitudinal direction is the front-rear direction. As shown in FIG. 1B , the press-formed product 1 includes the first plate-shaped portion 11, the second plate-shaped portion 12, and the third plate-shaped portion 13 forming a protruding portion 18 having a protruding cross-sectional shape. . Specific examples of shapes having a ridge cross-sectional shape include a hat-shaped shape and a u-shaped shape. In this embodiment, the press-molded product 1 is hat-shaped.

The press-formed product 1 is composed of a material in which two or more different steel plates are joined together, that is, a so-called tailored material. The press-formed product 1 includes a first steel plate 21 and a second steel plate 22 . The first steel plate 21 is high tensile steel with a thickness of 2.0 mm and a tensile strength of 1470 MPa. The second steel plate 22 is a high-tensile steel with a thickness of 1.2 mm and a tensile strength of 1470 MPa. The first steel plate 21 has relatively high strength compared to the second steel plate 22 . The second steel plate 22 is lighter than the first steel plate 21 when compared with the same area.

A joint portion 23 where these two steel plates are joined extends in the front-rear direction. Also, the joint portion 23 is positioned between the first bent portion 16 and the second bent portion 17 , that is, in a region excluding the first bent portion 16 and the second bent portion 17 . At the joint 23, the difference in thickness between the first steel plate 21 and the second steel plate 22 appears on the left side. On the other hand, there is no step on the right side of the joint 23 and it is flat. The left side of the joint portion 23 is, in other words, the inside of the ridge portion 18 , and the right side of the joint portion 23 is, in other words, the outside of the ridge portion 18 .

[1-2. Arrangement of press-formed products]
As shown in FIG. 2, the press-formed product 1 of this embodiment can be used as a side sill 33 that constitutes a part of the monocoque structure 31 of the vehicle body. In other words, the press-formed product 1 is a side sill that is arranged below a door that is arranged on the side of a vehicle so that the above-described front-rear direction is the front-rear direction of the vehicle. Side sills are also called rocker panels. The press-molded product 1 is joined to a center pillar 35 forming part of the monocoque structure 31 .

In the press-formed product 1, the first steel plate 21 is positioned above the second steel plate 22 when the press-formed product 1 is mounted on a vehicle as a side sill. The portion of the press-formed product 1 that is joined to the center pillar 35 is the upper portion of the second plate-shaped portion 12 , that is, the portion formed of the first steel plate 21 . The strength of the monocoque structure 31 can be increased by joining the high-strength center pillar 35 and the high-strength portion of the press-formed product 1 .

[1-3. Manufacturing method of press-molded product]
As shown in FIG. 3, the press-formed product 1 is manufactured through a step of tailor welding (S1), a step of laser trimming (S2), and a pressing step (S3).

In S1, as shown in FIG. 4, a tailored material 41 is manufactured in which the first steel plate 21a and the second steel plate 22a are joined at the joining portion 23. As shown in FIG.
In subsequent S2, laser trimming is performed along the laser-trimmed outline 42 to manufacture a blank material 43 including the first steel plate 21b and the second steel plate 22b.

In the following S3, first, as shown in FIG. 5, the blank material 43 is sandwiched between the upper mold 51 and the lower mold 52 from above and below. The lower molds 53 and 54 are fixed, and the upper mold 51 and the lower mold 52 are movable. The upper die 51 is a so-called punch, the lower die 52 is a so-called pad, and the lower dies 53 and 54 are so-called dies. Next, as shown in FIG. 6, the blank material 43 is sandwiched between the upper mold 51 and the lower mold 52 and moved downward to form the press-formed product 1 .

[1-4. effect]
According to the embodiment detailed above, the following effects are obtained.
(1a) In the press-formed product 1 of the present embodiment, both the relatively strong first steel plate 21 and the relatively light second steel plate 22 are arranged widely in the front-rear direction. Therefore, the widely arranged first steel plates 21 can not only exhibit high strength in the front-rear direction, but also can increase the strength in the left-right direction. In addition, since the first steel plate 21 eliminates the need for a reinforcing member for increasing the strength, and the light second steel plate is arranged over a wide range in the front-rear direction, the weight of the press-formed product 1 as a whole can be reduced. can be done.

(1b) In the press-molded product 1 , the joint portion 23 does not exist at the first bent portion 16 and the second bent portion 17 . If the joint portion 23 overlaps the bent portion, the ratio of the steel plate included in the bent portion changes due to a slight difference in the position of the joint portion 23, so that the strength of the bent portion tends to vary. However, in the press-formed product 1 of this embodiment, such danger can be reduced and the quality of the press-formed product 1 can be stabilized.

(1c) The press-molded product 1 can be used as a side sill 33 of a vehicle. Since the press-formed product 1 has high strength in the front-back direction and the left-right direction, it is possible to improve the safety against frontal collisions and side collisions of the vehicle. In addition, since the first steel plate having a higher strength is arranged on the upper side and joined to the center pillar 35 having a high strength and the portions having a high strength are joined to each other, the strength of the monocoque structure 31 can be set to an appropriate strength. The press-formed product 1 and the center pillar 35 may be joined directly or indirectly through another member. By using a member having high strength as another member, the strength of the monocoque structure 31 can be further improved.

(1d) In the press-formed product 1, the first steel plate 21 and the second steel plate 22 are joined so that the joint portion 23 is flat on the outer side of the protruding portion 18 and a step 23a is formed on the inner side due to the difference in thickness. . Therefore, when the outer surface of the protruding portion 18 is joined to another member, the joint can be satisfactorily achieved because there is no step on the outer surface.

(1e) The joint portion 23 is provided below the center of the second plate-like portion 12 in the vertical direction so that the upper side includes a large portion of the thick first steel plate 21 . Therefore, it is possible to increase the thickness of the portion on the upper side, and the strength of the press-formed product 1 can be increased. Furthermore, by providing the joint portion 23 to the second plate-shaped portion 12, it is possible to reduce the weight while maintaining the strength. easier to disperse. When the press-formed product 1 is mounted on the vehicle as the side sill 33 of the vehicle, the crew member sits on the upper side of the press-formed product 1, thereby further increasing the safety of the crew member.

[2. Other embodiments]
Although the embodiments of the present disclosure have been described above, the present disclosure is by no means limited to the above-described embodiments, and needless to say, can take various forms as long as they fall within the technical scope of the present disclosure.

(2A) In the above embodiment, the press-formed product 1 configured using the blank material 43 in which two different types of steel plates are joined at one joint portion 23 was exemplified. However, the press-formed product may be configured using two or more types of steel plates joined by two or more joining portions. In any case, all the joints may be located at positions other than the bends, or some or all of the joints may be provided at the bends.

(2B) In the above embodiment, the first steel plate 21 and the second steel plate 22 are made of 1470 MPa high-strength steel with different thicknesses. However, the first steel plate and the second steel plate are not limited to the plate thicknesses and materials described above. For example, the first steel plate and the second steel plate can be combined in various ways as long as they are steel plates having different plate thicknesses or steel plates having different materials and physical properties. When steel plates having different materials and physical properties are used, the thickness of the steel plates may be the same or different. Also, a steel plate other than the steel plate shown in the above embodiment may be used, or a steel plate having a thickness different from that of the above embodiment may be used.

In addition, as in the above-described embodiment, the portion of the second plate-shaped portion 12 above the joint portion 23 is made of a relatively high-strength steel plate (the first steel plate 21 in the embodiment), so that press forming can be performed. The product can have high strength suitable for side sills. Furthermore, by forming the first bent portion 16 from a high-strength steel plate as in the above-described embodiment, the strength of the press-formed product can be further increased. Of course, the portion of the second plate-shaped portion 12 below the joint portion 23 may be made of a steel plate having a relatively high strength.

(2C) The press-formed product 1 of the above embodiment may be modified as follows. For example, the joint portion 23 may be provided at the bent portion or may be provided so as to intersect the bent portion. Alternatively, it may be provided above the center of the second plate-shaped portion 12 in the vertical direction.

Moreover, like the press-formed product 101 of the modification shown in FIG. may have The undulating portion 111a is formed by varying the amount of protrusion of the second plate-shaped portion 111 in the left-right direction. Also, the step 113 a due to the difference in thickness between the two steel plates at the joint 113 may be formed outside the protruding portion 115 .

Also, the press-molded product of the present disclosure may be used for applications other than side sills. Of course, you may use it other than the vehicle body. In addition, the press-formed product of the present disclosure is not limited to a hat shape as long as it has a convex portion having a convex cross-sectional shape, and may be a U-shape or other shapes. good.

(2D) The function of one component in the above embodiment may be distributed as multiple components, or the functions of multiple components may be integrated into one component. Also, part of the configuration of the above embodiment may be omitted. Also, at least a part of the configuration of the above embodiment may be added, replaced, etc. with respect to the configuration of the other above embodiment. It should be noted that all aspects included in the technical idea specified by the wording in the claims are embodiments of the present disclosure.

DESCRIPTION OF SYMBOLS 1,101... Press-formed product 11... 1st plate-shaped part 12, 111... 2nd plate-shaped part 13... 3rd plate-shaped part 14... 1st flange 15... 2nd flange 16... 1st Bent part 17... Second bent part 18, 115... Protruding part 21... First steel plate 22... Second steel plate 23, 113... Joining part 23a, 113a... Step 31... Monocoque structure 33... Side sill 35 Center pillar 41 Tailored material 42 Laser trim outline 43 Blank material 51 Upper mold 52, 53, 54 Lower mold 111a Rising part

Claims (2)

A press-molded product,
The press-formed product is composed of a material in which a plurality of different steel plates are joined together,
A ridge portion having a length in a first direction and including three plate-like portions connected via at least two bent portions arranged side by side in a second direction intersecting the first direction. , comprising a ridge portion having a convex cross-sectional shape,
Among the plurality of steel plates, a joint where two steel plates are joined is located along the first direction,
The two steel plates have different plate thicknesses,
the second direction is a vertical direction;
The joint portion is provided below the center in the second direction of the plate-like portion having the bent portions at both ends of the three plate-like portions, and the outer side of the ridge portion is flat. are spliced as
The press-formed product is a side sill that is arranged below a door that is arranged on the side of a vehicle and that is arranged such that the first direction is the longitudinal direction of the vehicle,
including at least a first steel plate and a second steel plate relatively thinner than the first steel plate,
The first steel plate is a press-formed product positioned above the second steel plate when mounted on the vehicle . The press-molded product according to claim 1,
A press-formed product, wherein the joint portion is located in a region of the press-formed product excluding the bent portion.

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