JP2010076508A - Engine hood structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine hood structure that prevents an engine hood from being positioned too high, while efficiently absorbing the energy produced when a collision with an object occurs. <P>SOLUTION: The engine hood structure includes a gas layer 3 completely sealing an engine hood insulator 2 provided on a rear face 1a of an engine hood 1, and a gas exhaust valve 4 for exhausting gas in the gas layer 3 therefrom at a predetermined pressure or above. Therefore, collision-energy absorption efficiency of the engine hood insulator 2 can be further increased, thereby reducing a clearance S between the engine hood insulator 2 and an engine E. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an engine hood structure in which an engine hood insulator is provided on the back surface.

2. Description of the Related Art Conventionally, there is an engine hood insulator provided on the back surface of an engine hood so as to absorb an impact when a collision object collides with the surface of the engine hood. For example, a foam metal is disposed in a space between an engine hood and a hood frame disposed at a predetermined interval on the back surface of the engine hood, and collision energy is absorbed by the collapse of the foam metal ( For example, see Patent Document 1).
Japanese Patent Laying-Open No. 2006-21708 (page 4, FIG. 1)

  However, in such a conventional engine hood structure, the foam metal collapses when the impacted object collides and the engine hood is deformed. When the foam metal collapses and absorbs the collision energy, the foam metal The air inside remains in the foam metal storage chamber. For this reason, when the amount of deformation of the engine hood is large and the engine bottoms out, the remaining air may be compressed and the reaction force against the collision object may increase rapidly.

  Therefore, it is necessary to prevent the bottom of the engine hood, and for that purpose, the engine hood must be lifted away from the engine. It is subject to big restrictions.

  Therefore, the present invention provides an engine hood structure capable of efficiently absorbing energy when a collision object collides and suppressing an increase in the position of the engine hood.

  The present invention includes an engine hood provided at the front of a vehicle body, and an engine hood insulator provided on the back surface of the engine hood and absorbing an impact when a collision object collides with the surface of the engine hood. In the structure, the engine hood insulator is characterized in that it includes a sealed gas layer and a gas discharge valve that allows the gas in the gas layer to escape outward at a predetermined pressure or higher.

  According to the present invention, when the collision object collides with the surface of the engine hood and the engine hood is deformed, the collision energy is efficiently absorbed at the initial stage when the gas layer of the engine hood insulator is compressed along with the deformation. On the other hand, when compression of the gas layer progresses and the gas layer rises above a predetermined pressure, the gas discharge valve opens and the pressure in the gas layer rises abnormally to alleviate the reaction force. And the collision energy can be finally absorbed efficiently. Therefore, it is possible to prevent the position of the engine hood from being increased while efficiently absorbing energy when the collision object collides.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  1 to 6 show an embodiment of an engine hood structure according to the present invention, FIG. 1 is a perspective view of the engine hood, FIG. 2 is an enlarged sectional view taken along line AA in FIG. 1, and FIG. 4 is a perspective view of the hood insulator, FIG. 4 is an enlarged sectional view corresponding to FIG. 2 showing a state in which the impacted object collides with the engine hood, FIG. 5 is an enlarged sectional view of a portion B in FIG. It is an expanded sectional view corresponding to Drawing 5 showing the state where it collided with the engine hood.

  The engine hood 1 shown in FIG. 1 opens and closes an upper opening of an engine room (not shown) that is configured at the front of the vehicle body. Therefore, the engine hood 1 is disposed at the front of the vehicle body. As shown in FIG. 2, the rear surface (lower side in the figure) 1a of the engine hood 1 has an impact when a collision object H (see FIG. 4) collides with the surface (upper side in the figure) 1b of the engine hood 1. Is provided with an engine hood insulator 2 that absorbs water.

  As shown in FIGS. 2 and 4, an engine E is mounted below the engine hood 1 with a predetermined clearance S from the engine hood insulator 2.

  Here, in this embodiment, the engine hood insulator 2 is sealed with a gas layer 3 and a gas discharge valve 4 that releases the gas in the gas layer 3 (air in the present embodiment) to the outside at a predetermined pressure or higher. And comprising.

  That is, the gas layer 3 includes an upper side wall 31 that covers a required region of the back surface 1 a of the engine hood 1, and a lower side wall 32 that covers the lower side of the upper side wall 31, and the peripheral portions of the upper side wall 31 and the lower side wall 32. They are joined together to form a sealed structure. At this time, the upper side wall 31 is formed of a flexible sheet material, while the lower side wall 32 is formed of a highly rigid material such as a hard resin, so that the lower side wall 32 serving as the lower surface of the gas layer 3 is highly rigid. It is configured as a layer.

  Further, as shown in FIG. 3, the gas layer 3 has a cell structure partitioned into a large number of small chambers 34 by a partition wall 33, and the gas discharge valve 4 described above is provided in each small chamber 34. At this time, the many small chambers 34 have a honeycomb shape in the present embodiment.

  By the way, as shown in FIG. 5, the gas discharge valve 4 described above includes a valve seat 41 provided in a T-shaped cross section at the upper end portion of the partition wall 33, and an upper wall corresponding to a substantially central portion of the valve seat 41. An opening 42 formed in the valve 31 and a valve body 43 provided on the peripheral edge of the opening 42 are configured. Then, as shown in FIG. 6, when the air pressure in the small chamber 34 at the collision site becomes abnormally high due to the collision of the colliding object H, the gas discharge valve 4 is a valve body on the side of the small chamber 34 where the air pressure becomes high. 43 opens away from the valve seat 41. Then, the abnormally increased air pressure in the small chamber 34 passes between the valve body 43 and the valve seat 41 and is discharged outward from the opening 42, and the pressure in the small chamber 34 is reduced to a certain value or less. As a result, the gas discharge valve 4 is closed.

  Further, as shown in FIG. 5, the small chambers 34 communicate with each other through a communication hole 35 provided in the partition wall 33. Of course, the opening area of the communication hole 35 is set so as to have a desired air passage resistance when the air in the small chamber 34 passes.

  According to the engine hood structure of the present embodiment having the above configuration, when the collision target H collides with the surface 1b of the engine hood 1 from above almost as shown in FIG. Along with the downward deformation, the gas layer 3 of the engine hood insulator 2 is compressed and a reaction force is generated, so that collision energy can be efficiently absorbed at the initial stage when the gas layer is compressed.

  On the other hand, when compression of the gas layer 3 proceeds, when the gas layer 3 rises to a predetermined pressure or higher, the gas discharge valve 4 is opened and the pressure in the gas layer 3 is abnormally increased. The reaction force can be prevented from becoming excessive, and the reaction force to the collision object H can be reduced while maintaining the collision energy absorption effect.

  Therefore, the efficiency of absorbing the collision energy by the engine hood insulator 2 can be further increased, so that the clearance S between the engine ged insulator 2 and the engine E can be reduced. As a result, the position of the engine hood 1 can be suppressed from increasing while efficiently absorbing the energy when the collision object H collides.

  Moreover, the fact that the position of the engine hood 1 can be kept low in this way can improve the degree of freedom in the design of the front side of the vehicle body.

  Furthermore, since the gas layer 3 has a cell structure that is partitioned into a large number of small chambers 34 by the partition wall 33, the air compressed at the collision site of the collision object H can be prevented from diffusing in all directions from the collision site. . Thereby, since the air compression effect of the gas layer 3 can be utilized only in the collision part at the initial stage of the collision, the absorption efficiency of the collision energy can be further increased. At this time, since the gas discharge valve 4 is provided in each small chamber 34, it is possible to alleviate the abnormal increase in the air pressure in the small chamber 34 compressed at the collision site and prevent the reaction force from becoming excessive.

  Furthermore, since the lower side wall 32 serving as the lower surface of the gas layer 3 is configured as a highly rigid layer, the lower side wall 32 is compressed when the collision object H collides with the engine hood 1 and the air in the gas layer 3 is compressed. Can be prevented from deforming to the side where the engine E is disposed (downward in the figure). Thereby, since the air in the gas layer 3 can be compressed efficiently, the reaction force effect by the air pressure in the initial stage of the collision can be sufficiently obtained.

  In addition, since the small chambers 34 communicate with each other through the communication holes 35 provided in the partition wall 33, the air pressure in the small chambers 34 in which the pressure increases can move to the small chambers 34 through the communication holes 35. Thereby, even when there is a variation in the valve opening pressure of the gas discharge valve 4 provided in each small chamber 34, air can be stably discharged from the gas discharge valve 4 having the lowest valve opening pressure among the gas discharge valves 4. The collision energy can be absorbed efficiently.

  Further, by communicating the small chambers 34 with each other through the communication holes 35, the entire small chamber 34 can be filled with air through the respective communication holes 35 by injecting air from a part of the small chambers 34. Even when the gas layer 3 has a honeycomb structure, air can be easily injected, and the pressure in each chamber 34 can be made uniform. At this time, the opening area of the communication hole 35 is set to a desired air passage resistance so that the air passage speed is sufficiently slowed down, so that a pressure reaction force is reliably generated in the small chamber 34 at the collision site. Can do.

  By the way, the engine hood structure of the present invention has been described by taking the above embodiment as an example. However, the present invention is not limited to this embodiment, and various other embodiments can be adopted without departing from the gist of the present invention.

It is a perspective view of the engine hood concerning one embodiment of the present invention. It is an expanded sectional view along the AA line in FIG. It is a perspective view of the engine hood insulator concerning one embodiment of the present invention. FIG. 3 is an enlarged cross-sectional view corresponding to FIG. 2 showing a state in which an object to be collided according to an embodiment of the present invention collides with an engine hood. It is an expanded sectional view of the B section in FIG. FIG. 6 is an enlarged cross-sectional view corresponding to FIG. 5, showing a state in which an object to be collided according to an embodiment of the present invention collides with an engine hood.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine hood 1a Engine hood back surface 1b Engine hood surface 2 Engine hood insulator 3 Gas layer 32 Lower side wall (high rigidity layer)
33 Partition wall 34 Small chamber 35 Communication hole 4 Gas exhaust valve H Impacted object

Claims (4)

In the engine hood structure provided with an engine hood insulator that absorbs an impact when a collision object collides with the surface of the engine hood on the back surface of the engine hood arranged at the front of the vehicle body,
The engine hood insulator is provided with a gas exhaust valve for releasing the gas in the sealed gas layer outward at a predetermined pressure or more.   2. The engine hood structure according to claim 1, wherein the gas layer has a cell structure partitioned into a plurality of small chambers by a partition wall, and the gas discharge valve is provided in each of the small chambers.   The engine hood structure according to claim 1, wherein a highly rigid layer is provided on a lower surface of the gas layer.   The engine hood structure according to claim 2 or 3, wherein the small chambers communicate with each other through a communication hole provided in the partition wall.

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