JP6635105B2 - Closed section parts, vehicle structural parts, and method for improving shock absorption capacity - Google Patents

Description

  The present invention relates to a technique for providing a closed-section part having excellent collision resistance against an axial impact, and is particularly applicable to a structural part of an automobile or other vehicles.

2. Description of the Related Art In recent years, in the field of automobiles, application of high-strength materials to structural parts has been promoted for the purpose of achieving both vehicle weight reduction and collision safety performance for improving fuel efficiency in consideration of environmental issues.
There are two types of crash performance evaluation: axial crushing where the longitudinal direction of the component coincides with the collision direction, such as a frontal collision of an automobile, and bending crushing, which is perpendicular to the collision direction, such as a side impact. The buckling deformation absorbs the collision energy. In particular, in axial crushing, the entire circumference of the cross section of the component is alternately folded inward and outward, that is, deformation progresses in a bellows shape, thereby absorbing impact, and large deformation occurs particularly at the ridgeline portion.

On the other hand, as one of the conventional techniques for improving the collision resistance performance, there is a technique in which a shock absorbing component is disposed on a structural component and a rib-like lattice is used as the shock absorbing structure (Patent Document 1). reference).
In addition, a technique for improving the strength of a component by filling a foamed material inside a processed component has been proposed (Patent Documents 2 and 3).
Furthermore, a technique has been proposed in which a foam material is filled in a closed cross-sectional space provided in a cross section of a component to increase the shock absorbing ability (Patent Documents 4 and 5).

JP-A-2003-40063 JP-A-2002-36413 JP 2013-95264 A Japanese Patent No. 3596373 Japanese Patent No. 4729027

However, in the case of adding a shock-absorbing component as disclosed in Patent Document 1, the number of components of the structure is increased, so that the weight is increased in spite of the weight reduction and there is a problem in cost.
On the other hand, as in Patent Literatures 2 to 5, reinforcement with a foam filler requires a space of a predetermined size to fill the foam filler, and is provided in a cross section by the entire inner part of the component or a reinforcing component. It is necessary to fill the foam material so as to block the entire closed closed space. For this reason, there is a limit to the application parts or application locations, and the amount of foaming material required for filling tends to increase according to the closed space, and there is a problem in terms of weight reduction, cost, and recyclability. It can be said that.
The present invention has been made in view of the above points, and an object of the present invention is to easily improve the shock absorbing ability of a closed-section component by simple means.

  According to one embodiment of the present invention, there is provided a structure including a closed cross-sectional structure having one or more ridges extending along a longitudinal direction, and at least one ridge of the ridge in the structure. An adhesive applied continuously or intermittently to the inner surface side of the portion along the extending direction of the target ridge line portion so as to fill only the corner formed by the ridge line portion. It is characterized by.

  According to one aspect of the present invention, it is possible to easily improve the shock absorbing ability of the structure by a simple method of applying an adhesive so as to fill only the corners of the inner surface of the ridge.

It is a perspective view explaining the example of the structure concerning the embodiment based on the present invention. It is a figure explaining a section of a closed section component concerning an embodiment based on the present invention. It is a figure explaining the application position of an adhesive. It is a figure which shows the structure of Example 1, (a) is sectional drawing which shows a dimension, (b) is a perspective view. It is a figure explaining a maximum load.

Next, an embodiment of the present invention will be described with reference to the drawings.
(Constitution)
The closed-section component of the present embodiment includes a structure having a closed-section structure, and an adhesive applied to a part of the inner surface of the structure by coating.
As shown in FIG. 1, the structure 1 of the present embodiment is a structure manufactured by joining the flange portions 2c, 3c of the pair of hat-shaped cross-section members 2, 3 by welding. That is, in the present embodiment, as the structure 1, a component having a box-shaped closed cross-sectional structure having flange portions 2c, 3c will be described as an example. Each of the hat-shaped cross-section members 2 and 3 is formed by pressing a steel plate or another metal plate into a hat shape having top surfaces 2a and 3a, side walls 2b and 3b, and flanges 2c and 3c.

However, the member 3 may be a flat plate. That is, the closed cross section of the closed cross section structure does not need to be a rectangle, but may be a closed cross section having a polygonal cross section. Some of the sides of the polygonal cross section may not be straight lines, and may be arcuate. In short, the present invention can be applied to any closed cross-sectional structure having one or more ridges 5 along the longitudinal direction (axial direction) of the structure 1.
The structure 1 shown in FIG. 1 has four ridges 5 where each ridge 5A extends along the longitudinal direction. Each ridge line portion 5 is formed of a boundary portion having a corner of a boundary between the top surface portions 2a, 3a of the hat-shaped cross-section members 2, 3 and the side wall portions 2b, 3b as a ridge line 5A.

  In the present embodiment, the adhesive 6 is applied to the inner surfaces of the four ridges 5 so as to fill only the corners of each ridge 5, as shown in FIG. . The surface of the corner to which the adhesive 6 is applied is the angle side where the angle is less than 180. Each of the applied adhesives 6 is applied by being applied over the entire length of the ridge line portion 5 continuously along the extending direction of the ridge line portion 5. The adhesive 6 may be provided intermittently along the extending direction of the ridge line portion 5. Further, the adhesive 6 may be bonded to the corners of at least one of the two or more ridge lines 5.

Here, the supplement of filling only the corner inside the ridge line portion 5 with the adhesive 6 will be additionally described.
As shown in FIG. 3, the ridge line portion 5 includes a ridge line 5A and left and right surface portions 5B following the ridge line 5A in the closed cross section of the structure 1. The inner corner portion of the ridge line portion 5 includes a ridge line 5A and left and right surface portions 5B following the ridge line 5A inside the closed cross section. Applying the adhesive 6 so as to adhere to the ridge line 5A and the left and right surface portions 5B following the ridge line 5A is equivalent to filling only the inner corners of the ridge line portion 5 with the adhesive 6.

  The peel strength is secured by the area of the left and right surface portions 5B (the surface to which the adhesive 6 is applied), and the longer the lengths L1 and L2 of the left and right surface portions 5B from the ridge line 5A in the closed cross section, the more the adhesive is applied. It is presumed that the shock absorbing ability is improved, but the length L1, L2 of each surface portion 5B is 2 mm or more, preferably 5 mm or more. However, if the length is too long, the effect on the shock absorbing capacity is saturated, so that it is estimated that 2 cm or less is sufficient.

As the adhesive 6 to be used, a hardening adhesive made of a resin such as an epoxy resin or an acrylic resin is preferable. Although there are a photocuring component and a thermosetting component as the curing components, the thermosetting component is more preferable because the adhesive 6 is applied in a closed cross section.
Further, as the adhesive 6, it is preferable to employ an adhesive having high peel strength and impact resistance.

The peel strength is, for example, 1500 N / m or more, preferably 2000 N / m or more, and more preferably 5000 N / m or more. The shear strength is, for example, 20 MPa or more, preferably 30 MPa or more.
In order to improve the peel strength of the adhesive 6, the left and right surface portions 5B to which the adhesive 6 is applied may be roughened in advance.

The above-mentioned closed cross-section component made of the structure 1 with the adhesive 6 is suitable as a vehicle structural component.
The application of the adhesive 6 may be performed after the structure 1 is manufactured in a closed cross-section structure, or the adhesive 6 may be applied in the corners of the ridges 5 of the pair of hat-shaped cross-section members 2 and 3. Then, the pair of hat-shaped cross-section members 2 and 3 may be joined to form a closed cross-section structure.
The entire structure 1 does not need to have a closed cross section over the entire longitudinal direction of the component, and an opening may be partially formed along the longitudinal direction.

(Effects and others)
As described above, in the present embodiment, it is possible to easily provide a machined part having excellent shock absorbing ability without limiting the application location. Also, since the adhesive 6 only needs to be applied to the corners, the construction is easy.
Here, since the energy at the time of collision is absorbed by plastic deformation of the component, it is effective and efficient to reinforce the buckling portion of the component to improve the collision performance. In the present embodiment, the adhesive 6 is applied as a means for reinforcing the ridgeline portion 5 of the processed part.

That is, in the present embodiment, in order to increase the deformation resistance of the component, by providing the adhesive 6 at the corner on the inner surface side of the ridge line portion 5 of the cross section of the processed component, it is possible to easily improve the collision performance. .
The adhesive 6 is preferably made of a resin, and the resin is a curable type and has adhesiveness, thereby increasing deformation resistance and reinforcing a predetermined portion without restricting the arrangement of the adhesive 6. Is possible. Furthermore, since the number of components is not increased as compared with the case where reinforcing components are used, it is possible to easily obtain components having excellent collision performance while suppressing an increase in cost and mass.

Next, examples according to the present invention will be described.
(Example 1)
The adhesive 6 was applied to the four ridges 5 of the structure 1 having the same cross-sectional shape as that described in the embodiment, and the closed-section part of Example 1 was manufactured.
Here, the structural body 1 having a closed cross-sectional structure was formed using members 2 and 3 obtained by pressing high-tensile steel as shown in Table 1, and was manufactured to have the dimensions and shapes shown in FIG.

接着剤６としては、株式会社スリーボンドホールディングス製の高剥離・耐衝撃用接着剤であるThreeBond2249G（液状加熱硬化型エポキシ配合樹脂）を使用した。

As the adhesive 6, ThreeBond2249G (liquid heat-curable epoxy-containing resin), which is a high-peeling / impact-resistant adhesive manufactured by Three Bond Holdings, Inc., was used.

As shown in FIG. 2, the adhesive 6 was applied to the inside of the corner of the ridge line portion 5 so as to be applied at a position of 5 mm from the ridge line 5A toward the left and right surfaces. Note that the adhesive 6 was applied over the entire length of each ridgeline portion 5.
Then, after the adhesive 6 was applied, heat treatment was performed to cure the adhesive. The heat treatment condition is 170 ° C. × 20 minutes.
The increase in the mass of the structure 1 due to the application of the adhesive 6 was about 6% by mass.

(Comparative example)
A cross-sectional component of Comparative Example 1 was prepared and heat-treated under the same conditions as in Example 1 except that the adhesive 6 was not applied.
(Crash performance evaluation)
The maximum load when an axial load was applied to the closed cross-section parts of Example 1 and Comparative Example 2 at a predetermined collision speed (20 mm / min, 3 m / sec) was measured.
Specifically, evaluation was performed using a load-stroke curve as shown in FIG. 5, and the first peak load when the load was applied was defined as the maximum load. This is to evaluate the shock absorbing ability.
Table 2 shows the evaluation results.

表２から分かるように、接着剤６を塗布するだけで、衝突性能が約４％程度向上していることが分かる。

As can be seen from Table 2, it can be seen that the collision performance is improved by about 4% only by applying the adhesive 6.

DESCRIPTION OF SYMBOLS 1 Structural body 2, 3 Hat-shaped cross-section member 5 Ridge part 5A Ridge line 5B Surface part 6 Adhesive L1, L2 Length to which adhesive is applied

Claims (3)

A structure having a closed cross-sectional structure having one or more ridges extending along the longitudinal direction;
With respect to the inner surface side of at least one of the ridges of the structure, only corners formed by the ridge are continuously or intermittently filled along the extending direction of the target ridge. Adhesive and so on
Equipped with a,
The adhesive applied to the corners has a length of 5 mm or more and 2 cm or less from the ridge forming the corners, and the length of the adhesive applied to the left and right surface portions forming the corners is
The adhesive has a curable resin whose curable component is a thermosetting component. A vehicle structural part comprising the closed-section part according to claim 1 . A method for improving the shock absorbing capacity of a closed-section component having a closed-section structure having one or more ridges extending along a longitudinal direction, comprising:
On the inner surface side of at least one of the ridges, to fill only the corners formed by the ridges, continuously or intermittently along the extending direction of the target ridge, Apply the adhesive ,
The adhesive applied to the corners has a length of 5 mm or more and 2 cm or less from a ridgeline forming the corners, the length of the adhesive applied to the left and right surface portions forming the corners,
The method for improving the shock absorbing ability, wherein the adhesive has a thermosetting resin .

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