KR101750359B1 - Bumper beam for vehicle - Google Patents

Abstract

The present invention is configured to manufacture a profile having one kind of cross-sectional shape, to construct the bumper beam by arranging the two profiles facing each other in point symmetry and then joining them, so that only one kind of profile The present invention aims to provide a bumper beam for an automobile which can manufacture a bumper beam, thereby reducing manufacturing facilities and costs.
Particularly, according to the present invention, since the joint portion for forming the shock absorbing space to be deformed for shock absorption is formed in the shape of an acid, the portion actually in contact is curved so that even if the external impact is applied in any direction, It is an object of the present invention to provide a bumper beam for an automobile which is capable of obtaining a sufficient shock absorbing effect without being easily broken.
In addition, the present invention provides a bumper beam for a vehicle that can be manufactured easily and quickly because a profile of a bumper beam can be manufactured in a single profile through a roll forming method. There is another purpose.

Description

BUMPER BEAM FOR VEHICLE

The present invention relates to a bumper beam for an automobile, in which two kinds of profiles having a predetermined cross-sectional shape are arranged face to face with each other in a point symmetrical manner and then joined to form a bumper beam, So that the space for shock absorption of the bumper beam can be widened to improve the shock absorption performance.

The bumpers are mounted on the front and rear of the vehicle, respectively, to protect the driver and passengers by absorbing external impact when a collision or collision occurs. These bumpers were often made of steel to protrude from the car body. In recent years, however, a shock absorbing bumper capable of absorbing external shocks has become common. Such a shock absorbing bumper is usually made of a material having excellent impact absorbing force and restoring force. The following Patent Documents 1 to 3 disclose techniques relating to such a bumper and a bumper beam.

(Patent Document 1) Korean Patent Publication No. 10-2015-0132142

The cap profile having a central flange and having sides with side flanges which face inward toward the vehicle, The side flanges face outward from the vehicle and the hat profile includes a cover that is recessed into the hat profile and imparts a closed profile.

(Patent Document 2) Korean Patent Publication No. 10-2015-0132143

Wherein the bumper beam has a U-shaped profile and fasteners, the U-shaped profile directed in toward the vehicle and the fasteners are mounted on a side of the vehicle, And has mounting plates welded onto the fasteners for bolting to the end plates on the rails.

(Patent Document 3) Korean Patent Publication No. 10-2015-0143393

Claims [1] A rear bumper for a vehicle, comprising: two rod-shaped bodies of CFRTPC; One bridge of GMT interposed between the two rod-shaped bodies; Wherein the rod-shaped body and the bridge are integrally press-molded and have a shape of a rear bumper.

However, the conventional bumper beam causes the following problems.

(1) Normally, as shown in Fig. 1, a bumper beam is formed by joining two profiles (P1, P2) produced in a concavo-convex shape in the width direction so as to face each other, And is made to have spaces S1 and S2. Thus, the profiles P1 and P2 form at least one joint portion N for partitioning the shock absorbing spaces S1 and S2.

(2) This means that the two profiles P1 and P2, which make the existing bumper beam, are different, so that two profiles P1 and P2 must be produced, respectively. Therefore, since a mold or a roll forming apparatus for manufacturing each profile must be provided separately, the manufacturing facility is required to be large and a manufacturing cost is also required.

(3) Since these profiles P1 and P2 make the joint portions N flat, they may be misjudged when joining to cause defective joining. That is, the two profiles P1 and P2 are overlapped on the flat joint portion N so that the flat joint portions overlap each other, and then the two profiles P1 and P2 are joined to each other to manufacture the bumper beam. When the profiles P1 and P2 are overlapped, There is a fear of escaping, and therefore, a failure may occur at the joint portion.

(4) In addition, as shown in Fig. 1, when the external force is applied to the bumper beam due to collision or collision in the state where the bumper beam is mounted, There is a possibility that the shock absorber is not properly carried out and may put the driver or passenger at risk. That is, when the bumper beam is mounted on the vehicle, the joint portion N is vertically erected perpendicular to the traveling direction of the vehicle. Therefore, when the force generated by collision or collision is applied in the traveling direction of the vehicle, However, when the force is applied in an oblique direction to the traveling direction, the joint portion may be easily broken.

Although not shown in Fig. 5 (Fig. 1), in order to make the shock absorbing space like this, when two profiles are to be joined, both edges must be joined. Therefore, in the case of both edge portions of the impact absorbing space formed in the bumper beam, the size of the space becomes smaller by the joint portion as described above, so that the shock absorbing performance may be deteriorated.

Korean Patent Laid-Open No. 10-2015-0132142 (Publication date: November 25, 2015) Korean Patent Laid-Open No. 10-2015-0132143 (published on 2015.11.25) Korean Patent Publication No. 10-2015-0143393 (Publication date: December 23, 2015)

The present invention takes into consideration this point, and it is constituted such that a profile having one kind of cross-sectional shape is manufactured, two profiles thus produced are arranged facing each other point-symmetrically and then joined to form a bumper beam. The object of the present invention is to provide a bumper beam for an automobile which can manufacture a bumper beam even if only a plurality of kinds of profiles are produced, thereby reducing manufacturing facilities and costs.

Particularly, according to the present invention, since the joint portion for forming the shock absorbing space to be deformed for shock absorption is formed in the shape of an acid, the portion actually in contact is curved so that even if the external impact is applied in any direction, It is an object of the present invention to provide a bumper beam for an automobile which is capable of obtaining a sufficient shock absorbing effect without being easily broken.

In addition, the present invention provides a bumper beam for a vehicle that can be manufactured easily and quickly because a profile of a bumper beam can be manufactured in a single profile through a roll forming method. There is another purpose.

In order to achieve the above object, an automobile bumper beam according to the present invention includes a first and a second rim portion 110a and 110b, which are rounded at least twice round inward over an entire length, The first and second profiles P 'and P "formed by projecting at least one successive first and second joint portions 120 and 130, The first rim portion 110a of the first profile P 'is attached to the second rim portion 110b of the second profile P ", and the second rim portion 110b of the second profile P " And the second rim portion 110b of the first profile P 'is bonded to the first rim portion 110a of the second profile P ", and the second rim portion 110b of the first profile P' 1 bonding portion 120 is bonded to the second bonding portion 130 of the second profile P "and to the second bonding portion 130 of the second profile P & (130) are respectively bonded to a first bonding portion (120) of a second profile (P "), wherein the first bonding portion (120) is protruded in the form of a projection, and the second bonding portion 130) is characterized in that a joint surface (131) is formed at a portion in contact with the first joint portion (120) so as to accommodate the projecting portion.

In particular, the first and second profiles P 'and P "are formed by a roll forming process. The first and second profiles P' and P" And the bonding portion 120 and the second bonding portion 130 are formed one by one, respectively. Each of the first and second profiles P 'and P "has a flat surface that is an outer surface of the automotive bumper beam, and the first and second rim portions 110a and 110b, The first joint part 120 and the second joint part 130 are formed so as to protrude to one side.

In addition, the first joint part 120 is formed to be narrowed toward the outside, and its end is curved.

The second joint portion 130 has a joint surface 131 formed in a shape of a letter "W ". The first joint portion 120 has a flat end, Both of which are formed to be able to be held in contact with both sides of the second joint part (130) while being fitted to the joint surface (131).

Finally, the automotive bumper beam is characterized in that at least some sections of the bent portions of the profiles P 'and P "are partially softened

The bumper beam for a vehicle according to the present invention has the following effects.

(1) One kind of profile having a predetermined cross section with a predetermined width is produced, and in particular, the two profiles thus produced are arranged face to face with each other in point symmetry, and then joined to form a bumper beam. Beams can be manufactured, which can reduce manufacturing facilities and reduce manufacturing costs through mass production.

(2) Furthermore, since the bumper beam is manufactured using only one kind of profile, it is possible to reduce the installation space and the space utilization by reducing the size of the manufacturing facility.

(3) On the other hand, when the bumper beam is formed so that both sides of the profile are opposed to each other, the bimber beam having the same width is positioned in the space formed by the both edges of the profile according to the present invention. The edges of the joints do not protrude to the outside during manufacture, so that the shock absorbing spaces on both sides can be made wide. That is, the section modulus of the bumper beam can be maximized in a given space.

(4) As the space for absorbing the impact is widened, the shock absorption performance is as good as that, so that the thickness of the profile can be made thin. This not only reduces the manufacturing cost of the profile, but also reduces the weight of the bumper beam to improve the fuel economy of the vehicle.

(5) When the bumper beam is manufactured, the portion where the impact is to be absorbed is partially softened, such as where the stress is concentrated or the impact is expected to be applied, The softened portion can be easily deformed and the shock absorption can be performed well, so that the human life can be safely protected. Further, since the bumper beam formed by the same thickness of the bumper beam is partially softened through the roll forming process, it is difficult to apply a normal roll forming product manufactured with the same thickness to a partially different stiffness and strength It is possible to cope with the performance requirement that requires the roll forming process.

(6) When the two profiles produced according to the present invention are arranged to face each other in point symmetry and then joined to form a bumper beam, the joining portions are brought into contact with each other in an engaging manner like irregularities, The efficiency can be increased. Thus, according to the present invention, since the softening process is partially performed on the bumper beam made of the profile made to the same thickness through the roll forming process, the portion that is thickly formed until the thin portion can be made thin due to the rigidity of the other portion is softened It is possible to manufacture a bumper beam so as to obtain optimal shock absorption performance.

1 is a cross-sectional view showing an example of a bumper beam manufactured by joining two conventional profiles.
FIG. 2 is a perspective view showing a part of a length cut to show the overall shape of a profile according to [Embodiment 1] of the present invention. FIG.
3 is a side view for showing a cross-sectional shape of a profile according to [Example 1] of the present invention.
4 is a view showing a bumper beam produced by joining two profiles having the same cross section according to [Example 1] of the present invention, wherein (a) is a side view of a state before bonding, and (b) Side view of the post-bonding state.
[Fig. 5] is a side view showing a width section of a profile according to [Embodiment 2] of the present invention. [Fig.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should properly define the concept of the term to describe its invention in the best possible way The present invention should be construed in accordance with the spirit and scope of the present invention.

Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and are not intended to represent all of the technical ideas of the present invention. Thus, various equivalents And variations may be present.

The bumper beam according to the present invention is manufactured by arranging two profiles having the same configuration and having a predetermined length in a point symmetry manner facing each other. Here, the configuration of the profile will be described first, and the bumper beam using the profile will be described later.

(Configuration of profile)

The profile P according to the first embodiment of the present invention has first and second rim portions 110a and 110b facing each other on both sides with respect to a width section as shown in Figs. And at least one of the first joining portion 120 and the second joining portion 130, which are formed in an arcuate shape, are repeatedly protruded between the first and second rim portions 110a and 110b.

Particularly, since the two profiles P thus manufactured can be arranged facing each other in point symmetry and then joined to form a bumper beam, the bumper beam can be manufactured using one profile.

In addition, the present invention is characterized in that the end of the first joint part 120 is formed as a protrusion protruding outwardly, and the end of the second joint part 130 is formed in a shape capable of accommodating the protrusion part, So that the joint portion can be easily broken even in an external impact.

Hereinafter, this configuration will be described in more detail. Here, the reference symbol "P" is a profile having the same configuration as the first and second profiles P 'and P "used for manufacturing the bumper beam according to the present invention. In the drawings, the reference numerals for explaining the profile P will be described with reference to the reference numerals which are omitted from "" and "" ".

The first and second rim portions 110a and 110b are formed so that both edges of the profile P are folded at least twice over the entire length and face each other as shown in Fig. 2 and Fig. At this time, the first and second rim portions 110a and 110b are formed in such a manner that the two profiles P 'and P "having the same shape are symmetrically point-symmetrically opposed to each other to form the bumper beam 100 They are formed facing each other so as to be in contact with each other at the time of manufacture.

In the preferred embodiment of the present invention, the first and second rim portions 110a and 110b are formed such that the remainder of the bumper beam, except for the portion that is in contact when making the bumper beam, But the present invention is not limited thereto. That is, as shown in FIG. 4 (a), the upper two first and second rim portions 110a 'and 110b' and the lower two first and second rim portions 110a 'and 110b' If it is a form that can be joined, there is no problem even if it is made in the form of folding several times.

The first bonding portion 120 and the second bonding portion 130 are formed in a concavoconvex form so as to be positioned between the first and second rim portions 110a and 110b as shown in FIGS. 2 and 3 It is formed by breaking. At this time, it is preferable that the first joint portion 120 and the second joint portion 130 are formed so as to protrude in a mountain shape, respectively, so as to reinforce the structural rigidity of the bumper beam 100.

The first bonding portion 120 and the second bonding portion 130 are preferably formed at positions corresponding to each other as shown in Figs. 2 and 3, respectively. That is, as shown in FIG. 4, when two profiles P 'and P "formed in the same shape are joined to each other, To allow the first bonding portions 120 'and 120' 'to be bonded to the respective second bonding portions 130' and 130 '. Here, the point symmetry refers to a conventional technique of obtaining a corresponding point obtained by rotating each point of a figure by 180 DEG with respect to a symmetry point.

In the preferred embodiment of the present invention, the second bonding portion 130 is provided with a bonding surface 131 (see FIG. 4) so that the ends of the first bonding portion 120 can be contacted and bonded, ). This makes it possible to easily recognize the overlapping positions when the two profiles P 'and P " are overlapped with each other in point symmetry so as to join the two profiles P' and P " Even if an impact is applied to the bumper beam 100 in an oblique direction with respect to the running direction, the first joint portion 120 is not easily detached or broken at the second joint portion 130 by this impact, To be done.

In the preferred embodiment of the present invention, it is preferable that the first bonding portion 120 and the second bonding portion 130 have a curved end portion as in [FIG. 2] to [FIG. 4] . This is because even if an impact is applied to the profiles P 'and P "constituting the bumper beam 100, it is concentrated at the end portion so as to be deformed without being damaged.

In a preferred embodiment of the present invention, it is preferable that the first bonding portion 120 and the second bonding portion 130 are formed in the same number as at least one each. This is because, as described later, when the profiles according to the present invention are arranged in a point symmetrical manner so as to face each other and then to be joined, the first joining portion 120 and the second joining portion 130 facing each other are joined to each other If the number is different, bonding can not be done. Accordingly, it is preferable that the first bonding portion 120 and the second bonding portion 130 are formed in pairs, and the number of the first bonding portion 120 and the second bonding portion 130 are repeatedly formed according to the width of the bumper beam.

The profile according to the present invention as described above can be manufactured by various methods. However, by adopting the roll forming method, it is possible to manufacture a desired length regardless of the length of the profile, and also to mass- have.

It is preferable that the profile according to the present invention is formed as a flat plate as a whole using a steel plate or the like, and the rim portion and the joining portion are formed so as to protrude in either direction so that the other surface of the profile is entirely planar.

(Manufacture of bumper beam)

The present invention includes the bumper beam 100 manufactured as shown in FIG. 4, using a profile having a predetermined length. Here, the bumper beam 100 is manufactured using the first profile P 'and the second profile P "of the same shape. Here, the first and second profiles P' and P" The same configuration as the profile P is as described above.

On the other hand, the bumper beam 100 is manufactured by arranging the first and second profiles P 'and P "so as to face each other in point symmetry as shown in Fig. 4 (a) The first joint portion 120 'of the first profile P' is brought into contact with the second joint portion 130 "of the second profile P" through the point symmetrical arrangement, and the first profile P ' Quot;) of the second profile P "to the second joining portion 130 'of the first profile P' '' at the same time. At the same time, the rim portions as well as these joining portions also contact each other. The contact portion is bonded by a conventional technique of bonding the profile when the bumper beam is manufactured such as spot welding, fusion welding, and high frequency heat treatment.

At this time, the first and second joint parts 120 'and 120' 'and the second joint parts 130' and 130 '' are fitted in a concavo-convex shape so that the first and second joint parts 110a 'and 110a' Only the second rim portions 110b 'and 110b "may be bonded by a normal bonding method such as spot welding, welding, or high-frequency processing. This makes it possible to easily manufacture the bumper beam because the rim portion is firmly fixed so as to maintain the overall shape and can withstand external forces, and the joint portions of the bumper portions are coupled to each other in a concavo-convex shape, To be able to obtain. Of course, it is possible to fix the first and second bonding portions 120 'and 120' 'with the second bonding portions 130' and 130 'in a bonding manner such as spot welding, fusion bonding and high frequency heat treatment.

On the other hand, in the bumper beam according to the present invention, as shown in Figs. 2 and 3, in order to manufacture the profile P, the bumper beam is subjected to a softening treatment for a part (indicated by "A" . The softening treatment is a conventional heat treatment method for softening the steel material or improving the machinability. In the present invention, the softening treatment is first applied to a portion where deformation is applied when an external impact is applied, . This softening process can be softened to about 60% of the stiffness of the bumper beam, for example. That is, when the bumper beam produced according to the present invention has a strength of 1.7 GPa in a portion not subjected to the softening treatment, the softening portion softens at a strength of about 1 GPa.

The softening treatment may be performed over the entire length of the bent portion, but it is preferable to partially soften the portion where the first impact is expected when the external impact is applied or the first deformed portion when the external impact is applied .

Generally, when the bumper beam is formed in a profile formed by roll forming, it is difficult to partially change the stiffness and strength because the bumper beams have almost the same thickness. However, the bumper beam according to the present invention can be easily deformed The softened portion is relatively deformed compared with the portion having only the roll forming process so that the direction in which the shock absorption is performed is given So that the shock absorbing performance can be improved. Therefore, the present invention can improve the utilization of the roll forming process.

<Bending Analysis of Bumper Beam>

The results of the three-point bending analysis of the bumper beam and the conventional bumper beam according to the present invention are as follows. At this time, "Forge 2011" was used as the FEM analysis program for the bend analysis, and the bumper beam was made into the profile made of 1.7 GPa material and having a thickness of 1.2 mm. The results of this bending analysis are shown in Table 1 below.

division

Comparative Example
Example 1



section

Material / Thickness

1.7 GPa / 1.2 mm
1.7 GPa / 1.2 mm
Yield strength

1480 MPa
3 point bending resistance

Up to 15.5ton
24.2 ton




Analysis schematic

1) In the analytical schematic, the gray portions on both sides represent a die, the middle gray portion represents a punch, and the portion between the dies represents a bumper beam.

2) The stroke of the punch is 20 mm.

In Table 1, it can be seen that the three-point bending resistance is as high as 8.7 tons as compared to that of Comparative Example of 15.5 tons in [Example 1].

As described above, according to the present invention, since two types of profiles are arranged facing each other in a point symmetrical manner and then bonded together to produce a bumper beam, a profile required for producing a bumper beam can be produced. It is possible to reduce the investment cost of the facility and to produce only one profile, so that the productivity can be increased.

In order to manufacture the bumper beam, since the portions to be joined with the two profiles are formed in a mountain shape, they are brought into contact with each other in a curved shape instead of a plane, so that even when an external force is applied to the joint portion, So that the shock absorbing effect can be enhanced.

[Example 2] according to the present invention differs in the shape of the first bonding portion 120a when the profile Pa is produced as compared to [Example 1], as shown in Fig. Here, the same reference numerals are used for the same components as those of the profile described in [Embodiment 1], and a detailed description thereof will be omitted.

[Embodiment 2] In the embodiment 2, as shown in Fig. 5, the first joint part 120a to be brought into contact with the second joint part 130 is formed so as to protrude from the middle part. In other words, the second joint part 130 is formed in a shape of a "W" as a whole due to its curvature so as to accommodate the end of the first joint part 120a, and the first joint part 120a, 2 joining portion 130 so as to be in contact with the second joining portion 300 in such a manner that the central portion thereof protrudes.

Accordingly, the first bonding portion 120a supports the lower portion of the " W "shape forming the second bonding portion 130 while the middle portion thereof protrudes outward, and the center of the" W " It becomes a fitted type.

This is because the portion protruding from the end of the first joint portion 120a is fitted to the second joint portion 130 as described in [Embodiment 1], so that the bumper beam can be easily assembled, Thereby preventing the joining portions of the two profiles constituting the metal plate from being easily broken. At this time, since both the protruding portions of the first bonding portion 120a are bonded to each other facing the second bonding portion 130, they serve to support the impact without being deformed due to the impact.

As a result of the three-point bending analysis with the bumper beam bonded and fabricated by arranging two profiles having the same structure in a point-symmetric manner in the same profile as the above-described profile, the results are as follows. At this time, the test conditions are the same as in [Example 1].

division

Comparative Example
Example 2


section

Material / Thickness

1.7 GPa / 1.2 mm
1.7 GPa / 1.2 mm
Yield strength

1480 MPa
3 point bending resistance

Up to 15.5ton
26.9 ton




Analysis schematic

1) In the analytical schematic, the gray portions on both sides represent a die, the middle gray portion represents a punch, and the portion between the dies represents a bumper beam.

2) The stroke of the punch is 20 mm.

As described above, it can be seen that the present invention improves to 26.9 tons in [Example 2] while it is 15.5 tons in [Comparative Example] at three-point bending resistance, which is higher than 24.2 tons in [Example 1] .

100: Bumper beam
110a: first rim portion
110b: second rim portion
120: first bonding portion
130: second joint portion
131:

Claims (7)

A first joining portion 120 formed in a mountain shape by being folded in a concave-convex shape over the entire length between first and second rim portions 110a and 110b which are formed so as to be rounded at least twice round the entire length, The first and second profiles P 'and P "formed so that the first and second joint portions 130 and 130 protrude at least one by one in a point-symmetrical manner, ,
The first and second profiles P ' and P "each have a cross-sectional shape of one kind,
The first rim portion 110a of the first profile P 'is located in the second rim portion 110b of the second profile P "and the second rim portion 110b of the first profile P' Are joined to the first rim portion 110a of the second profile P &quot;, respectively,
The first bonding portion 120 of the first profile P 'is bonded to the second bonding portion 130 of the second profile P "and to the second bonding portion 130 of the first profile P' Are joined to the first bonding portion 120 of the second profile P &quot;, respectively,
The first joint part 120 is protruded in the form of a protrusion and the second joint part 130 is provided with a joint surface 131 to receive the protrusion at a portion contacting the first joint part 120, Wherein the bumper beam is made of a metal.
The method according to claim 1,
The first and second profiles P 'and P "
Wherein the bumper beam is formed by a roll forming process.
The method according to claim 1,
The first and second profiles P 'and P "
Wherein the first joint part (120) and the second joint part (130) are formed one by one, respectively.
The method according to claim 1,
The first and second profiles P 'and P "
The surface forming the outer surface of the automotive bumper beam is flattened as a whole,
Wherein the first and second rim portions (110a, 110b), the first joint portion (120) and the second joint portion (130) are formed so as to protrude to one side.
The method according to claim 1,
Wherein the first joint part (120) is formed so as to become narrower toward the outside, and the end of the first joint part (120) is curved.
The method according to claim 1,
The second bonding portion 130 has a bonding surface 131 formed in a "W" shape at its end,
The first joining portion 120 has a flat end and a central portion protruding so that the center of the first joining portion 120 is fitted to the joining surface 131 while both the first joining portion 120 and the second joining portion 130 are in contact with each other Wherein the bumper beam is a bumper beam for an automobile.
7. The method according to any one of claims 1 to 6,
The bumper beam for an automobile includes:
Characterized in that at least some sections of the bent portions of the profiles (P ', P ") are partly softened.

Images