JPH05112190A - Structure of bumper - Google Patents

Abstract

PURPOSE:To provide a structure of a bumper which has simple structure and can lessen impact securely. CONSTITUTION:In a bumper which has a bumper face 2 made of resin and a bumper reinforcement 3, at least one rib 23 which is extended horizontally and in the longitudinal direction up to the vicinity of the bumper reinforcement is formed integrally at the back of a longitudinal wall section of the bumper face, and a pair of projections 33 are formed in the front section of the bumper reinforcement in opposition to the rib so that up and down movement of the rib is regulated by the projections and impact force is absorbed by deforming the rib securely when impact is applied.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bumper structure, and more particularly to a bumper having a simple structure and capable of reliably absorbing an impact.

[0002]

2. Description of the Related Art In a vehicle, bumpers are generally provided on the front side and the rear side of a vehicle body as a safety measure to reduce the impact in the event of a collision. Further, in recent vehicles, there is a tendency to reduce the weight from the viewpoint of improving fuel efficiency. The bumper described above is also made of synthetic resin material such as urethane elastomer in place of metal material, and is provided with reinforcing ribs to secure structural strength and to reduce weight (for example, actual opening flatness). 1-1532
Also in such a resin bumper, it is required that the impact can be reliably mitigated for safety reasons.

Therefore, in a conventional resin bumper, for example, as shown in Japanese Patent Publication No. 62-10857, a shock absorber such as urethane foam is provided between a resin bumper face and a bumper reinforcement, A method of absorbing the impact force by deforming the resin bumper face and the impact absorber has been proposed.

[0004]

However, in the conventional bumper structure, since the shock absorber is provided inside the bumper to absorb the shock, the number of parts is increased and the assembly work is complicated. There was a problem that there was.

In view of the above problems, it is an object of the present invention to provide a bumper structure having a simple structure and capable of reliably absorbing impact.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, provided a rib extending horizontally toward a bumper reinforcement on a resin bumper face, and the rib was provided at the time of impact. The present invention has been completed, focusing on the fact that the impact on the vehicle interior can be significantly reduced by deforming the vehicle to absorb the impact force.

Therefore, the structure of the bumper according to the present invention is a bumper having a resin bumper face and a bumper reinforcement, which is formed integrally extending horizontally and in the longitudinal direction from the back surface of the vertical wall portion of the bumper face to the vicinity of the bumper reinforcement. The gist of the present invention is to provide at least one rib and a pair of protrusions that face the rib at the front portion of the bumper reinforcement and that restrict the vertical movement of the rib.

Here, the bumper face can be manufactured by using a thermoplastic resin. Further, the bumper reinforcement may be made of a metal material, but it is also preferable that the bumper reinforcement is made of a resin material from the viewpoints of weight reduction and projection production.

[0009]

[Function] When an impact is applied to the bumper face and the bumper face is deformed, the tips of the ribs come into contact with the bumper reinforcement and the ribs themselves also begin to deform. At this time, the tips of the ribs are fitted between the pair of protrusions of the bumper reinforcement to regulate the vertical displacement, and as a result, the ribs are securely deformed without falling, thereby absorbing the impact force. In this way, the ribs on the bumper face side are deformed while being regulated by the protrusions on the bumper reinforcement side to absorb the impact force. Therefore, the structure is simpler than the conventional impact absorber. Can reduce the impact.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the specific examples shown in the drawings. 1 to 3 show a structure of a bumper according to an embodiment of the present invention. As shown in FIG. 1, the bumper 1 of this structure is configured by combining a synthetic resin bumper face 2 and a synthetic resin bumper reinforcement 3. The bumper face 2 is the upper wall 2
0, the vertical wall portion 21 and the lower wall portion 22 are formed into a substantially U-shaped cross section, and the bumper reinforcement 3 also has a substantially sectional shape including the upper wall portion 30, the vertical wall portion 31 and the lower wall portion 32. It is shaped like a U.

The vertical wall portion 2 of the bumper face 2 is also provided.
1 upper and lower ribs 23 are integrally formed on the back surface, and both of the ribs 23 extend horizontally to the vicinity of the bumper reinforcement 3 and continuously extend in the longitudinal direction by a predetermined dimension. Vertical ribs 24 are formed between the upper and lower ribs 23 at appropriate intervals. On the other hand, as shown in FIGS. 2 and 3, a pair of protrusions 33 are integrally formed on the front surface of the vertical wall portion 31 of the bumper reinforcement 3 so as to face each of the ribs 23. At the time of impact, the tip of the rib 23 is sandwiched with a predetermined play, and the vertical movement of the rib 23 is regulated.

Next, the function and effect will be described. When an impact acts on the bumper 1 of this structure in the direction of arrow A in FIG. 1,
The bumper face 2 made of resin is deformed by the impact force toward the bumper reinforcement 3 side, and at the same time, the tips of the upper and lower ribs 23 respectively come into contact with the vertical wall portions 31 of the bumper reinforcement 3 and the ribs 23 also start to be deformed. ..
At that time, the upper and lower ribs 23 are both fitted between the pair of protrusions 33 on the bumper reinforcement 3 side and their vertical displacement is restricted, and the ribs 23 are surely deformed without falling in the vertical direction, and the resin bumper. The impact force is absorbed by the deformation of the face 2 and the ribs 23, and the impact on the vehicle interior is significantly reduced, so that safety can be guaranteed.

In the structure of the bumper of the present embodiment as described above, the rib 23 on the bumper face 2 side is deformed while the vertical displacement is restricted by the protrusion 33 on the bumper reinforcement 3 side, so that the impact force is reduced. The shock can be reliably absorbed and the impact on the passenger compartment can be greatly mitigated. Moreover, the number of parts is smaller than in the case where a conventional shock absorber is provided, and the structure can be simplified to simplify the manufacturing work.

Next, the difference in shock absorbing power between the bumper structure of the present embodiment and the bumper structure in which the vertical displacement of the rib is not restricted by the protrusion will be theoretically explained. As shown in FIG. 6, it is assumed that the impact ridge 4 applies a load of 1 ton to the bumper face 2 and that the impact load acts on the upper and lower ribs 23 equally.
It is assumed that a load of 00 kg acts. FIGS. 6 (a) and 6 (b) show the experimental operation viewed from the plane and the side. Now, the effective pressurization length is bcm and the bumper face 2 is E
Is set to 9000 kg / cm @ 2, I = bh3 / 12, and Euler's buckling formula is used: P = n * [pi] 2 * (EI / l2) = n * 9.86 * (9000 * b * 0.253 / 32 *) 12) = n × b × 12.8 Equation 1 is obtained. Further, in the structure of the bumper, when the protrusion 33 is provided, the tip of the rib 23 is constrained as shown in FIG. 7B, so that n = 2, and when the protrusion 33 is not provided,
As shown in FIG. 7A, since the tip of the rib 23 is not constrained, n = 1/4. Since the bumper face 2 has a roundness, assuming that the effective pressurizing length is 25 cm, from the formula 1, when there is no protrusion 33, P0 = 1/4 x 25 x 12.8 = 80 (kg) When there is the protrusion 33, P1 = 2 × 25 × 12.8 = 640 (kg)> 500 (kg), and the rib 23 is deformed without buckling with respect to an impact load of 1 ton and absorbs the impact. In theory, there is a difference of about eight times in shock absorbing power between the case where the tip to which the load is applied is restrained and the case where the tip is set to the free end. That is, while there is play, there is friction at the tip even when it is made a free end, so the difference is considered to be about 3 to 4 times. Also, when a prototype was manufactured and the difference in shock absorbing power was confirmed, there was some error due to the prototype, but in the case of the protrusion 33, the load was about 12
It was confirmed that, while the impact of 00 kg or more can be absorbed, the deformation becomes large at about 800 kg without the protrusion 33, and the impact load of more than that cannot be absorbed.

4 and 5 show a bumper structure according to another embodiment of the present invention. In the figure, the same reference numerals as those in FIGS. 1 to 3 denote the same or corresponding parts. In this embodiment, the projections 35 are formed on the front surface of the vertical wall portion 31 of the bumper reinforcement 3 at predetermined intervals, instead of being formed continuously in the longitudinal direction. Even if the protrusions 35 are formed at intervals as described above, the same effect as the above embodiment can be obtained, but since it can be easily understood, detailed description thereof will be omitted.

[0016]

As described above, according to the structure of the bumper according to the present invention, in the bumper having the resin bumper face and the bumper reinforcement, the bumper face is provided horizontally on the back surface of the vertical wall portion up to the vicinity of the bumper reinforcement. At least one rib extending in the longitudinal direction is integrally formed, and a pair of projections is formed in the front part of the bumper reinforcement so as to face the ribs, and the ribs are deformed while restricting the vertical movement of the ribs due to the impact action. Since the impact force is absorbed, there is an effect that the impact can be reliably absorbed with a simple structure.

[Brief description of drawings]

FIG. 1 is a sectional side view showing a structure of a bumper according to an embodiment of the present invention.

FIG. 2 is a front view showing a bumper reinforcement in the structure of the bumper.

FIG. 3 is a plan view showing the bumper reinforcement.

FIG. 4 is a front view showing a bumper reinforcement in a bumper structure according to another embodiment of the present invention.

FIG. 5 is a plan view showing the bumper reinforcement.

FIG. 6 is a view for theoretically explaining the operation of the bumper structure according to the present invention.

FIG. 7 is a diagram for explaining the above operation.

[Explanation of symbols]

 1 Bumper 2 Bumper face 23 Rib 3 Bumper reinforcement 33 Protrusion 35 Protrusion

Claims (1)

[Claims] 1. A bumper having a resin bumper face and a bumper reinforcement, wherein at least one rib is formed integrally extending horizontally and longitudinally from the back surface of the vertical wall portion of the bumper face to the vicinity of the bumper reinforcement, and the bumper. A bumper structure comprising: a pair of protrusions, which are provided at a front portion of the reinforcement and which face the ribs and regulate vertical movement of the ribs.