JP3334639B2 - Door impact beam - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a door impact beam for protecting an occupant in a vehicle in the event of a car accident, for example, by absorbing an impact force due to a collision or the like and preventing a large deformation of the door.

[0002]

2. Description of the Related Art In order to increase the strength of an automobile door, various guard beams or impact beams for an automobile door mounted inside the door have been proposed (hereinafter collectively referred to as door impact beams). As a conventional example of a door impact beam, see, for example,
No. 6684 can be cited. FIG. 7 is an external perspective view showing a door impact beam disclosed in the publication (referred to as a guide beam in the publication).
Door impact beam 10 finished by molding
1 is a palm part 10 having a divergent shape at both ends.
2 between which a beam 103 is formed. Beam portion 103 is formed into a substantially equilateral triangle cross section, toward the center of the bottom plate 105 portion from the apex portion side directed toward the outside of the vehicle body, the strut portion 104 in a state where a metal plate superposed widthwise end portions formed Have been. In such a door impact beam 101, when an impact load is applied from the outside of the door, the force is dispersed and transmitted to the support portion 104 and the side plate portion 106, so that the stress is not concentrated and sudden buckling occurs. The effect of absorbing the impact load can be obtained without generating the cracks.

[0003]

However, such a conventional door impact beam 101 has a strut 104
Although the effect of dispersing the impact load applied to the beam portion 103 is provided by providing the beam, sufficient strength cannot be obtained by itself. That is, when the entire door impact beam 101 is viewed, the beam portion 1
This is because stress concentration due to an impact load occurs in the shape change portion of the portion P that continues to 03. In this regard, in the conventional door impact beam 101, the beam portion 103
The side plate 106 gradually decreases toward the palm 102 to avoid stress concentration.

[0004] However, as described above, the stress applied to the door impact beam 101 must be taken into consideration with respect to the strut portion 104 because the impact load applied from the outside of the door is dispersed to the strut portion 104 and the side plate portion 106. Was. However, the conventional door impact beam 101
As shown in FIG. 7, the end of the support portion 104 is
5, and the shape of the palm part 102 is particularly similar to the part P continuous with the beam part 103.
There has been the most width is narrowed. Therefore, the conventional door impact beam 101 includes the palm section 102 and the beam section 10.
It is inevitable that a large stress is applied to the portion P continuous with No. 3, and it cannot be said that sufficient strength was obtained.

[0005] Therefore, the present invention is to solve these problems, and an object thereof is to provide a door impact beam to obtain a sufficient strength.

[0006]

According to the door impact beam of the present invention, both ends in the width direction of the metal plate are wound around the center.
To form an inner strut with its tip abutting against the inner surface.
Cylindrical part and joints formed at both longitudinal ends of the metal plate
A door impact beam comprising:
Forming a continuous portion between the portion and the end of the cylindrical portion
Forming joints at both ends in the width direction of the plate from the cylindrical part
Form a notch that spreads out in a C-shape over the part,
Wrap both ends in the width direction of the cylindrical part in the center,
The tip comes into contact with the inner surface of the cylindrical part, and the joint
Wherein the inner pillar portion is formed to intervene between the two. Therefore, this reduces a sudden change in the load applied from the tubular portion to the joint, and provides a door impact beam having sufficient strength to prevent buckling due to stress concentration.
It can be easily formed.

[0007] The door impact beam according to the present invention is characterized in that the front end of the inner support portion contacts the cylindrical portion.
Continuing with the surface, a U-shaped
With a groove, formed a flat fixed surface on both sides across it
It is characterized by the following. Therefore, the continuity between the tubular part and the joint part
It is possible to easily form a door impact beam having a sufficient strength by reducing stress concentration in a portion where the door impact beam is formed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of a door impact beam according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic view showing an appearance of a door impact beam according to the present embodiment. The door impact beam 1 is formed by pressing a single metal plate (not shown) punched into a predetermined shape, and is formed of a tubular portion 2 capable of absorbing an impact force. It is provided with joint portions 3 for attachment at both end sides. The door impact beam 1 is mounted inside, for example, an automobile door (not shown), absorbs a strong impact force on the door due to collision between automobiles, suppresses a large deformation of the door, and protects a person inside the automobile. It works.

The door impact beam 1 has a cylindrical portion 2 designed to absorb an impact force applied to an automobile door.
For example, it is formed in a shape as shown in FIG.
FIG. 2 is a cross-sectional view of the door impact beam 1 taken along line AA of FIG. The cylindrical portion 2 includes three closed spaces 21A, 21B, and 21C shown in the figure inside the cylinder, and is formed by cutting a metal plate punched into a predetermined shape.
Both sides in the width direction are formed by being rolled into the center. Specifically, both end portions 22 in the width direction of the metal plate
a and 22b are folded inward with a width equal to or greater than the diameter of the cylindrical portion 23, and approximately half of their lengths abut each other . The end portions 22a and 22b are divided into left and right ends in the cylindrical portion 23 so as to form a central closed space 21C.
Is formed. The end portions 22a and 22b have inner ends P1 and P2 that contact the inner surface of the cylindrical portion 23 and function as supports for preventing the tubular portion 2 from flattening.

Next, a portion of the door impact beam 1 which is a feature of the present invention and which is continuous with the cylindrical portion 2 and the joint portion 3 will be described. FIG. 3 is a perspective view showing a continuous portion B of the tubular portion 2 and the joint portion 3 of the door impact beam 1 shown in FIG. 1, and FIG. 4 is a side view of the portion B. Since the cylindrical portion 2 has a cylindrical shape as shown in FIG. 2, the joint portion 3 formed continuously with the cylindrical portion 2 has a U-shaped groove 3 b in the center portion, and A flat fixing surface is provided on each side of the sandwich. A flange 31 is formed in a continuous portion from the tubular portion 2 to the joint portion 3 so as to extend from the cylindrical portion 23 of the tubular portion 2 to the end of the joint portion 3 in the same manner as in the conventional example. ing.

In the present embodiment, the inner pillar portions P1 and P2 of both end portions 22a and 22b in the width direction of the metal plate provided in the cylindrical portion 2 are formed to have tapered axial end surfaces. I have. This is achieved by forming a notch 32 opened in a C-shape at a predetermined distance at an axial end of a metal plate 5 for forming the door impact beam 1 as shown in FIG. As a result, as shown in FIGS. 3 and 4, a middle flange 33 which protrudes from the tubular portion 2 toward the joint portion 3 and whose bottom side is in contact with the groove 3 b is formed.

Here, the relationship between the load and the displacement when a concentrated load is applied vertically to the central cylindrical portion with respect to the door impact beam fixed by the joints at both ends will be described with respect to the conventional example and the present embodiment. The results of measurement of the above are shown below. FIG. 6 is a graph showing the relationship between the load and the displacement of the load point in the door impact beam of the present embodiment and the conventional example. As shown in FIG. 6, the displacement of the load point is almost proportional to the load in the embodiment of the present invention shown by the broken line, whereas in the conventional example shown by the solid line, in the initial stage when the load is applied. Large displacement occurred. This is considered to be caused an Dan large deformation in a portion P which continues from palm portion (joint portion) 102 shown in FIG beam portion (tubular portion) to 103. Therefore, from this result, it can be said that the stress concentration in the continuous portion between the tubular portion 2 and the joint portion 3 was reduced by the middle flange 33, and sufficient strength was obtained in the door impact beam 1.

The present invention is not limited to the above-described embodiment, and various changes can be made without departing from the gist of the present invention. For example, the cross-sectional shape of the cylindrical portion 2 is not limited to one in which the inner support portions P1 and P2 are formed from one metal plate 5 as shown in FIG. Is also good. The door impact beam 1 is also provided on the side of the joint 3 with a flange 31.
The middle flange 33 is provided even without this.
It is possible to obtain a sufficient strength by the body. Further, both end portions 22 of the metal plate forming the inner support portions P1 and P2.
a and 22b may be open or closed with respect to each other.

[0014]

According to the present invention, there is provided a cylindrical portion formed by winding a metal plate in the width direction, and joints formed at both ends in the longitudinal direction of the metal plate. A metal plate having an inner strut formed by winding both ends in the width direction into the center and having its tip abutting on the inner surface of the tubular portion, the inner strut interposed from the tubular portion to the joint portion. With this configuration, it is possible to provide a door impact beam with sufficient strength.

Further, according to the present invention, the metal plate forming the continuous portion of the joint portion and the end portion of the tubular portion is provided at both ends in the width direction from the tubular portion forming portion to the joint portion forming portion. A notch that spreads out in the shape of a square is formed, and the widthwise opposite ends of the cylindrical part forming part of the metal plate are wound around the center, and the tip is brought into contact with the inner surface of the cylindrical part. Since it is configured so as to be interposed between the joints, a door impact beam having sufficient strength can be easily formed.

[Brief description of the drawings]

FIG. 1 is an external perspective view showing an embodiment of a door impact beam according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG. 1, showing a shape of a cylindrical portion 2 of the door impact beam 1 according to the present invention .

FIG. 3 is a perspective view of a portion B of the door impact beam 1 shown in FIG.

FIG. 4 is a side view of a portion B of the door impact beam 1 shown in FIG.

FIG. 5 is a developed view showing a metal plate for forming a portion B of the door impact beam 1 shown in FIG.

FIG. 6 is a graph showing a relationship between a load and a displacement of a load point in a door impact beam of the present embodiment and a conventional example.

FIG. 7 is an external perspective view showing a conventional door impact beam.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Door impact beam 2 Tubular part 3 Joint part 5 Metal plate 31 Flange 33 Middle flange

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-9-267634 (JP, A) JP-A-8-216684 (JP, A) JP-A-9-104302 (JP, A) JP-A-7-267 315048 (JP, A) JP-A-10-58973 (JP, A) JP-A-10-58972 (JP, A) JP-A 62-78519 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60R 21/02-21/04 B60J 5/00-5/04

Claims (2)

(57) [Claims] 1. Wrapping both ends in the width direction of a metal plate in the center
In the door impact beam including a tubular portion having its inner end portion formed by contacting the tip with the inner surface and a joint portion formed at both ends in the longitudinal direction of the metal plate, the joint portion includes Form a continuous part with the end of the cylindrical part
At both ends in the width direction of the metal plate to be formed,
Form a notch that spreads out in the shape of a square over the claw part
And wind both ends in the width direction of the cylindrical part of the metal plate
And the front end thereof is brought into contact with the inner surface of the cylindrical portion to form the inner column portion interposed from the cylindrical portion to the joint portion.
Door impact beam characterized by that. 2. The door impact beam according to claim 1, wherein a front end of the inner support portion is connected to an inner surface of the tubular portion.
Subsequently, a U-shaped groove is provided at the center in the width direction of the joint.
And a flat fixed surface formed on both sides of the door impact beam.