JP3494254B2 - Hood edge structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hood edge structure along a front edge of a hood that opens and closes an engine room of an automobile, and more particularly, is adapted to absorb impact energy by being deformed when it interferes with an external obstacle. Regarding the hood edge structure.

[0002]

2. Description of the Related Art For example, Japanese Utility Model Laid-Open No. 61-134492 discloses that a vehicle hood is formed of an outer panel having an outer surface and an inner panel having an inner surface. A vehicle body structure in which a collapsed space is formed on the front side in the direction is described. This crushed space absorbs impact energy by deforming and crushing when an obstacle hits it from the outside, and prevents the obstacle and the body part of the vehicle from being damaged.

Further, as shown in FIG. 1, a hood edge 03 is formed on the upper surface of the front grill 01 in the front of the engine room to receive the hood 02 when it is closed and along the front edge thereof to form an extension of the hood. It is also possible to provide a crushed space 04 similar to the above by the upper plate 03a and the lower plate 03b of the hood edge, and further to install a foam body 05 such as polyurethane as an energy absorbing material in this space. Are known.

At this hood edge, impact energy is absorbed by the deformation of the foam body 05 in addition to the upper and lower plates 03a, 03b. In FIG. 1, reference numeral 06 denotes a beam for receiving a reaction force when the foam body 05 is deformed, which is fixed to the vehicle body.

[0005]

[Problems to be solved] By the way, the above-mentioned actual development 61-
The one described in Japanese Patent No. 134492 tries to absorb the impact energy acting on the front edge portion of the hood only by the deformation of the outer panel and the inner panel forming the crushed space, so that a sufficient energy absorbing action can be obtained. Therefore, the hood lock mechanism behind the crushed space and the hood body are likely to be affected.

On the other hand, in the case where the foam is installed in the collapsed space, a large amount of energy can be absorbed by the deformation of the foam. However, the load-stroke curve at the time of compressive deformation of the foam is as shown in FIG. 2, and the load characteristic is not flat with respect to the stroke, and the load gradually increases according to the stroke, so the energy absorption characteristic is Not efficient. That is, in order to absorb the desired amount of energy E, a large crash stroke S ₁ is required, and the load P ₁ at this time also becomes large.

Therefore, the beam 06 that supports the foam body 05 against the external force F _A acting on the hood edge 03 from the front must be strong enough to withstand the load P ₁ , resulting in an increase in cost. There are problems such as weight increase.

Further, in order to secure the crash stroke S ₁ against the external force F _A , the front-back length of the entire hood edge 03 must be increased according to the foam body 05.
This front-rear length becomes longer for the following reasons.

That is, the foam has a crushing efficiency a / b.
(A is the stroke length when crushed to the maximum, b is the member length) is bad, only about 70% of the member length can be crushed, and 30% remains without being crushed. I have to make it longer.

In addition to the external force F _A from the front side, an external force F _B acts on the hood edge 03 from diagonally above, but if the beam 06 is provided on the rear side of the foam body 05 as shown in FIG. However, it is not possible to absorb the energy corresponding to the vertical component of this force F _B , for which an additional beam under load on the foam 05 is required.

However, since such a lower beam limits the stroke length with respect to the force F _A from the front side, the front-rear length of the hood edge 03 has to be further lengthened accordingly, and the beam length is also increased. The cost is further increased by the increased amount, and the weight is increased.

[0012]

The present invention has been made to solve the above problems in the prior art. In the present invention, the front edge of the hood that opens and closes the engine room of an automobile is defined. In the hood edge structure along, the hood side is fixed and extends forward and forms a collapsible space by the upper plate and the lower plate that are fitted to each other at the front end, and the inner bumper extends in the space between the upper plate and the lower plate. The inner bumper is provided with a slope portion that extends forward and obliquely upward from the vicinity of the fixed portion of the lower plate, and further bends rearward at the upper portion of the slope portion and the upper portion near the fixed portion of the upper plate. joined top portion is provided in a plate, shock et
Absorb nergi by buckling.

According to the present invention, the upper plate and the lower plate forming the collapsible space are fixed at their rear ends and extend forward, and the inner bumper is arranged between the upper plate and the lower plate. Therefore, by bending and buckling deformation of the upper plate, the lower plate and the inner bumper, it is possible to effectively absorb energy against both the external force applied to the hood edge from the front and the external force applied obliquely from above. it can.

Since the crush deformation of the hood edge structure according to the present invention has a flat load characteristic, the energy absorption efficiency is good, and the crush efficiency is also good. Therefore, the required energy can be sufficiently absorbed in a short crash stroke. .

[0015]

FIG. 3 is a side view of a front portion of an automobile showing an embodiment of the present invention, in which 1 is a front wheel, 2 is a front fender, and 3 is a front panel.

Reference numeral 4 denotes a hood which covers the upper opening of the engine room so that the upper opening can be opened and closed, and when the opening is closed, a front edge 4a thereof is provided.
Are received by the hood edge 5 arranged along the upper surface of the front panel 3. At this time, the hood edge 5 forms an extension of the hood 4 along the front end edge 4a of the hood 4, and the outer surface of the hood 4 is smoothly smoothed by the front panel 3
Connect to the upper edge of.

FIG. 4 is a vertical sectional view of the hood edge 5 taken along the center line of the vehicle body. The hood edge 5 is joined to each other at the front end a to form a space 6 having a substantially triangular cross section.
And the lower plate 8 and the inner bumper 9 arranged in the space 6
It is composed of and. The upper plate 7, the lower plate 8 and the inner bumper 9 are made of a resin material such as polyurethane, polypropylene or polyester, and are formed into a relatively thin plate-like body by using a material having a low bending elastic modulus.

The rear edge of the upper plate 7 is connected to a mounting beam 10 provided on the vehicle body side and is fixed to the vehicle body through the mounting beam 10, and at this fixed portion, the front edge of the hood 4 is received. Support this. The outer surface of the upper plate 7 is the hood 4.
Is smoothly connected to the outer surface to form an extension surface of the outer surface, and is bent downward toward the front to reach the front end edge a.

The lower plate 8 formed integrally with the upper plate 7 extends rearward from the front end edge a substantially horizontally, and the rear end edge thereof is connected to a mounting beam 11 similar to the mounting beam 10 so that the mounting beam 11 is formed. It is fixed to the car body via.

The inner bumper 9 has a sloped portion 9a extending forward and obliquely upward from the vicinity of the rear end edge of the lower plate 8 and a rearward bend at the upper portion of the sloped portion 9a to the rear end edge of the upper plate 7. It is composed of an upper surface portion 9b that extends and a sloped portion 9a.
The lower end edge of the lower plate 8 is fixed to the mounting beam 11 together with the rear end edge of the lower plate 8, and the rear end edge of the upper surface portion 9b is fixed to the mounting beam 10 together with the rear end edge of the upper plate 7.

When a force F _A is applied to the hood edge 5 from the front due to an obstacle or the like, the upper plate 7 and the lower plate 8 are deformed to crush the space 6, and the inner bumper 9 is further deformed to absorb energy. As a result, the influence of the above force on the vehicle body and obstacles is mitigated, but at this time, the rear ends are fixed to the mounting beams 11 and 10, respectively, and extend in the front-back direction, that is, substantially parallel to the action line of the force F _A. The lower plate 8 and the upper surface portion 9b of the inner bumper 9 are buckled and deformed, and the inclined portion 9a is also buckled and deformed by the component force of the force F _A along the buckling deformation.

The energy absorption effect by these buckling deformations is very large, and a large amount of energy can be absorbed thereby.

Further, since the energy is absorbed by the buckling deformation in this way, when the hood edge 5 is crushed in the front-rear direction by the force F _A , the relationship between the stroke and the load is as follows.
As shown in FIG. 5, the load characteristics are relatively flat. Therefore, efficient energy absorption is performed, and the stroke S ₂ and load P ₂ required to absorb a desired amount of energy can be small. That is, the front-rear length of the hood edge 5 can be shortened, and the reaction force applied to the vehicle body side and the obstacle side can be reduced. Therefore, it is not necessary to make the mounting beams 10 and 11 particularly strong.

Although the scale of each coordinate is different between FIG. 5 and FIG. 2, when S ₂ = S ₁ , P ₁ > P ₂ , P ₁ =
When P ₂ , S ₂ <S ₁ .

Further, since the hood edge 5 does not have a foam or the like as an energy absorber inside, the hood edge 5 can be crushed to almost the full length thereof, and the above-mentioned crushing efficiency is good. The length can be shortened.

An external force F _B applied to the hood edge 5 obliquely downward from the front upper side thereof is fixed at its lower end by a mounting beam 11 and extends obliquely upward to the front and extends substantially parallel to the action line of the external force F _B. Inner bumper 9 sloped portion 9a
Are opposed to each other and buckle, and the upper surface portion 9b is also deformed, so that energy can be efficiently absorbed.

[0027]

[0028]

[0029]

The hood edge structure according to the present invention can effectively absorb energy against both an external force applied from the front and an external force applied obliquely from above, and its crush deformation has a flat load characteristic. The energy absorption efficiency is good, and the crushing efficiency is also good. Therefore, the required energy can be sufficiently absorbed in a short crash stroke. In addition, because it does not require an extremely long nose shape, it has a high degree of freedom in design.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a conventional hood edge structure.

FIG. 2 is a graph showing a load-stroke curve when a foam is compressed and deformed.

FIG. 3 is a side view of a front portion of an automobile showing an embodiment of the present invention.

FIG. 4 is a vertical cross-sectional view of a hood edge, which is an embodiment of the present invention, taken along the center line of the vehicle body.

FIG. 5 is a graph showing a relationship between a stroke and a load when the hood edge is crushed and deformed.

[Explanation of symbols]

1 ... front wheel, 2 ... front fender, 3 ... front panel, 4 ... hood, 5 ... hood edge, 6 ... space, 7 ... upper plate, 8 ... Lower plate, 9 ・
..Inner bumper, 10, 11 ... Mounting beam.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B62D 25/10 B60R 21/34 692

Claims (2)

(57) [Claims] 1. A hood edge structure along a front end edge of a hood that opens and closes an engine room of an automobile, in which a crushable space is formed by an upper plate and a lower plate which are fixed to the hood side and extend forward to meet each other at the front end. The inner bumper is formed in the space over the space between the upper plate and the lower plate, and the inner bumper is provided with a sloped portion extending forward and obliquely upward from the vicinity of the fixed portion of the lower plate. An upper surface part that is bent backward at the upper part and is joined to the upper plate near the fixed part of the upper plate is provided, and the impact energy is absorbed by buckling.
A hood edge structure that can be stored . 2. The hood edge structure according to claim 1, wherein the upper plate, the lower plate and the inner bumper are integrally formed.