JP4287614B2 - Body panel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention particularly relates to an automobile hood.ToThe present invention relates to a vehicle body panel that is suitable and excellent in safety at the time of a pedestrian's head collision.
[0002]
[Prior art]
Conventionally, body panels such as automobile hoods and doors are combined with an outer panel (exterior panel, outer plate) and an inner panel (interior panel, inner plate) combined in a closed cross-sectional structure through a space. A panel is used widely.
[0003]
These composite panels, especially the inner panels, are made of high-grade materials such as 2000 series, 3000 series, 5000 series, 5000 series, 7000 series, etc. in accordance with AA or JIS standards in order to reduce the weight in place of the conventionally used steel sheets. Strong and highly formable aluminum alloy plates are starting to be used.
[0004]
The composite panels of automobiles such as the hood are required to have high rigidity after being made thinner and lighter, and they are required to have high bending rigidity, torsional rigidity, or tension rigidity (dent resistance). ing. For this reason, the inner panel plays an important role in reinforcing these rigidity.
[0005]
As an inner panel made of an aluminum alloy, there is a beam type panel which has been well known as a steel plate. As shown in a perspective view in FIG. 9, the beam type panel 16 is an inner panel composed of a plurality of beams 17 by partially trimming (removing) the panel to reduce the weight.
[0006]
Separately from this, it is called a cone type disclosed in USP 5,244,745, USP 6,012,764, USP 5,124,191, and JP 2000-168622, etc., which has a plurality (large) of convex portions on the surface. An aluminum alloy inner panel is known. As shown in the perspective view of FIG. 10, this cone-shaped panel 18 has a relatively large convex portion (projection, dimple) 19 whose top is directed to the outer panel side, which is called a cone having a truncated cone shape (a trapezoidal cross section). Many are provided on the panel surface. The protrusions 2 are individually independent protrusions, and a space between the protrusions is a flat plate or a recess. In FIG. 10, a bead (convex portion) extending in a U-shape, for example, which is widely used for reinforcing the panel rigidity is provided in the peripheral portion of the inner panel.
[0007]
However, in recent years, in addition to these performances, the composite panels of automobiles have been newly required to ensure collision safety for pedestrians and the like. Among these, in particular, automobile hoods are required to ensure safety when heads of adults and children pedestrians collide. More specifically, the automobile hood has an internationally low HIC value (Head Injury Criteria) as, for example, 1000 or less as a safety standard in the case of a pedestrian head collision. It is demanded.
[0008]
Regarding this collision safety, when the pedestrian's head collides with the automobile hood, the outer panel and inner panel (composite panel) are deformed toward the engine inside the hood, and the internal engine compartment built-in (rigid) The next collision results in a large reaction force, which is secondary but gives a large impact to the head. This reaction force significantly increases the HIC value to 1000 or more.
[0009]
Figure 7 shows the relationship between head acceleration and time (solid curve) during head collision. As shown in FIG. 7, the peak of the first wave of acceleration to the head at the time of head collision is a collision of the pedestrian head with the automobile hood (deformation of the automobile hood). As can be seen from FIG. 7, the peak of acceleration has a peak P2 of the second wave following the peak P1 of the first wave. This is the reaction force generated by the secondary collision of the automobile hood panel with the internal engine compartment built-in (rigid body) described above. Here, the HIC value is an integral value of the curve of acceleration and time in FIG. 7. In order to lower the HIC value, it is necessary to lower the peaks of the first wave and the second wave of the acceleration.
[0010]
However, it is difficult to reduce the peak of the first wave of acceleration itself. This is because the peak of the first wave of acceleration depends on the deformation characteristics (rigidity) of the panel of the automobile hood. In order to lower the peak of the first wave, the structure of the hood panel and the characteristics of the materials used (such as yield strength) are changed to reduce the rigidity of the automobile hood panel. However, as described above, automobile hood panels are required to have high rigidity after being reduced in thickness and weight as basic required characteristics, and the rigidity of the hood as a whole cannot be reduced. Even if the overall rigidity is reduced, the peak of the second wave of acceleration increases as the deformation stroke of the panel increases, and the HIC value itself cannot be lowered.
[0011]
Therefore, as a practical matter, in order to lower the HIC value, it is necessary to lower the peak of the second wave of acceleration rather than the peak of the first wave of acceleration.
[0012]
A major problem in reducing the peak of the second wave of acceleration is the distance (clearance) between the automobile hood panel and the internal engine compartment. The peak of the second wave of acceleration is a panel in the automobile hood where the distance between the hood panel 4 (inner panel 1) and the internal engine compartment built-in (clearance S shown in FIGS. 2 and 5 described later) is relatively small. In this case, the size increases depending on the panel part.
[0013]
If this interval is small, the kinetic energy at the time of a pedestrian head collision cannot be absorbed and the hood panel is deformed, causing a secondary collision with the engine room built-in, resulting in a large reaction force on the head. Become. In this case, the peak P2 of the second wave of acceleration is significantly larger than the peak P1 of the first wave of acceleration, as shown in FIG. This tendency is remarkable when the minimum distance between the engine room built-in item inside the hood and the hood inner panel is particularly 50 mm or less.
[0014]
On the other hand, in the automobile hood panel, the internal engine room built-in thing is not directly below, such as the panel area where the interval is relatively large, even when the hood panel is greatly deformed at the time of a pedestrian head collision, Since it does not collide with the internal engine room built-in (rigid body), the peak of the second wave of the acceleration does not occur and the HIC value is originally low.
[0015]
However, in the structure of automobiles today, there are inevitably parts where the above-mentioned distance cannot be increased due to an increase in the size of the engine accompanying an increase in the displacement or an increase in the number of mounted parts due to the increase in functionality. Therefore, there is a need for a hood panel structure that can reduce the acceleration peak at the time of a pedestrian's head collision even with such a panel or panel portion.
[0016]
In addition, the pedestrian's head cannot identify which part of the vehicle body panel collides. For this reason, a vehicle body panel excellent in safety at the time of a pedestrian's head collision is a part where the pedestrian's head collides with any (arbitrary) part of the body panel and the part where the interval is small Even if the head of a pedestrian collides, it is necessary to have excellent collision safety.
[0017]
[Problems to be solved by the invention]
The beam-type inner panel corresponds to a panel region having a relatively large interval in the case of a collision with a space portion where the panel is trimmed. Therefore, the peak of the first wave and the second wave of acceleration shown in FIG. Will not grow. However, when the pedestrian head indicated by h in FIG. 9 collides with the beam 17 disposed on the beam type inner panel, the acceleration shown in FIG. The peak P1 of the first wave becomes significantly large. Therefore, even if a pedestrian's head collides with any part of the vehicle body panel, it cannot be said that the collision safety is excellent.
[0018]
On the other hand, the cone-type inner panel is superior to the beam-type inner panel in safety at the time of a pedestrian's head collision. In addition to this cone-shaped convex part, when a predetermined convex part is provided on the inner panel, such as a convex part having an inner panel which will be described later having a substantially corrugated cross-sectional shape, safety when a pedestrian collides with the head. Improve sexiness.
[0019]
However, it is not easy to form a convex portion having a shape excellent in safety at the time of a pedestrian's head collision on the inner panel by press molding. The convex part with excellent safety at the time of a pedestrian's head collision needs to be relatively or sufficiently large in size such as the height of the convex part and the width of the convex part in order to improve the rigidity of the vehicle body panel. Because there is. In order to mold such a large convex portion, there are limitations in terms of the characteristics of the material plate and press molding conditions. For this reason, the said convex part actually provided in an inner panel must restrict | limit to a smaller thing from the height and the width | variety anticipated from the safety | security at the time of a pedestrian's head collision.
[0020]
For this reason, in particular, in the vehicle body panel portion where the distance between the inner panel and the internal built-in object (rigid body) is relatively small as described above, the deformed vehicle body panel is separated from the rigid body during a pedestrian head collision indicated by h in FIG. Because of the secondary collision, there is a possibility that the reaction force to the head becomes large. In this case, the peak P2 of the second wave of acceleration shown in FIG. 7 is significantly increased. Therefore, even if a pedestrian's head collides with any part of the vehicle body panel, it cannot be said that the collision safety is excellent.
[0021]
Therefore, at present, regardless of whether a beam-type inner panel or a cone-type inner panel is used, no matter where the pedestrian's head collides with the body panel such as a hood, the HIC value is reduced to 1000 or less. There is no proper body panel structure means. As a result, the interval of the minimum interval portion is increased to a value exceeding a considerable amount of 50 mm, and the actual situation is that the height of the hood or bonnet is increased. And when this minimum space | interval part is enlarged, the design of an automobile hood, a design, etc. have to receive restrictions and sacrifice greatly.
[0022]
In addition, for the convenience of the design and design of automobile hoods, in the case where the minimum interval portion is reduced to 50 mm or less, including the beam type panel and the like, as in JP-A-5-155356, the weight increase and The actual situation is that a space between the outer and the inner panel is filled with a shock absorber such as glass wool. However, in order to produce the effect only by using the shock absorber, it is necessary to select a considerable amount and material sufficient to fill the space between the outer and the inner panel. For this reason, the weight reduction of the vehicle body is sacrificed, and the cost for filling the shock absorber and the work are complicated.
[0023]
In view of such circumstances, an object of the present invention is to provide a vehicle body panel provided with an inner panel, in which case the pedestrian's head collides with any (arbitrary) part of the vehicle body panel, and the distance is small. An object of the present invention is to provide a vehicle body panel that is excellent in collision safety even when a pedestrian's head collides with a part.
[0024]
[Means for Solving the Problems]
  In order to achieve this object, claim 1 of the present inventionVehicle body panel for automobile hood with excellent safety at the time of pedestrian head collisionThe gist is on the back of the outer panelMade of steel plate or aluminum alloyIn the vehicle body panel to which the inner panel is joined, the inner panel has a structure in which a peripheral panel and a central panel are integrally joined, and the peripheral panel is joined to the outer panel at a peripheral part thereof, The center part panel is formed with a convex part whose top part is directed to the outer panel side.
[0025]
  Hereinafter, a hood as a vehicle body panel will be described. FirstIn the present invention, the central panel is formed with a convex portion whose top is directed to the outer panel side. And this convex part presupposes that it is the convex part shape which was excellent in the safety | security at the time of a pedestrian's head collision, preferably having the said cone shape or a substantially waveform cross-sectional shape.
[0026]
However, as described above, it is not easy to form a plurality of convex portions having a shape excellent in safety at the time of a pedestrian's head collision at a predetermined interval on the inner panel by press molding. Even an ordinary inner panel is press-molded according to the shape design of the vehicle body panel. However, when a convex part having a shape excellent in safety at the time of a pedestrian's head collision is formed on the center panel by press molding, press molding to a shape according to the shape design of the vehicle body panel is performed. Furthermore, press molding of a convex portion having a shape excellent in safety at the time of a pedestrian's head collision is added. Also, in the convex part with excellent safety at the time of a pedestrian's head collision, it is necessary to make the convex part height and convex part width relatively large in order to improve the rigidity of the vehicle body panel. There is.
[0027]
It is extremely difficult to form an inner panel having such a large protrusion and a shape corresponding to the shape design of the vehicle body panel. Therefore, an extra process such as forming a plurality of times by dividing the process or reworking the shape is inevitably required. Even if these are performed, the yield is inevitably lowered due to the occurrence of molding defects.
[0028]
In the present invention, in view of such a situation, as an inner panel base plate, the inner panel is not composed of a single single plate, but is separated (divided) into a peripheral panel and a central panel. The configuration. As a result, the center panel corresponding to the center of the original inner panel is molded to provide a convex shape with excellent safety during a pedestrian head collision, and the original shape according to the shape design of the body panel Both of them are easy to form.
[0029]
In other words, the central panel is provided with a convex portion having a shape that is excellent in safety at the time of a pedestrian's head collision and can reinforce the required rigidity of the vehicle body panel, if necessary. In addition, the original inner panel shape according to the shape design of the vehicle body panel is formed.
[0030]
On the other hand, the peripheral panel is separately press-molded into a design shape that is joined to the outer panel at the peripheral edge of the outer panel, and, if necessary, to a shape that compensates for rigidity that is insufficient with only the central panel. And after these shaping | molding, a center part panel and a peripheral part panel are joined and integrated as an inner panel. However, after providing a convex part with excellent safety in the case of a pedestrian's head collision on the center panel, it is joined and integrated with the peripheral panel, and then the inner part according to the shape design of the body panel You may shape | mold into the whole panel shape.
[0031]
Here, the center panel in the present invention refers to an inner panel portion that is excellent in safety at the time of a pedestrian's head collision and has an area, a width, or a planar shape where this is required. On the other hand, the peripheral panel in the present invention is an inner panel that is not particularly required to have safety when a pedestrian collides with the head, has excellent rigidity, and has a region, a width, or a planar shape to be joined to the outer panel. Say the part.
[0032]
Therefore, the center panel gives top priority to providing a convex shape that is excellent in safety at the time of a pedestrian's head collision. For this purpose, means such as selecting a material with low yield strength that can easily form the convex shape on the central panel, or reducing the thickness of the central panel even if it is the same type of material as the peripheral panel, etc. Is appropriately selected. However, the adoption of these means inevitably lowers the rigidity as the inner panel.
[0033]
On the other hand, the peripheral panel gives the highest priority to compensating for the lower rigidity of the central panel. For this purpose, means such as selecting a material with high yield strength for the peripheral panel, or making the peripheral panel thicker than the central panel even if it is the same type of material as the central panel. Is appropriately selected.
[0034]
In the present invention, preferably, as described in claim 2, a plurality of through holes having a sound absorbing effect are provided in the center panel and / or a plurality of sound absorbing effects are provided on the back surface of the center panel. Since the sound absorbing panel provided with the through hole is provided, it is possible not only to protect the pedestrian's head at the time of collision, but also to provide a sound absorbing effect to the vehicle body panel. For this reason, for example, in the case of an automobile hood (bonnet), by using the through hole and the sound absorbing panel of the central panel in combination or independently, the engine sound inside the hood is absorbed and reduced, and the vehicle travels. A comfortable sound absorbing effect can be obtained. In addition, the central panel can be reduced in weight by providing the plurality of through holes.
[0035]
Further, preferably, as described in claim 3, by making the peripheral panel plate thickness thicker than the central panel plate thickness, the overall rigidity of the inner panel and the overall rigidity of the hood panel are further increased. Can be improved. And on the other hand, it becomes possible to make the said center part panel thin, and to make it easy to shape | mold the said convex part in the shape for increasing the protection property at the time of a pedestrian's head collision. In addition, by these means, it is possible to achieve the safety at the time of a pedestrian's head collision and the required rigidity of the vehicle body panel without impeding the weight reduction of the vehicle body panel.
[0036]
The effect of the present invention can be achieved by an inner panel composed of a thin plate having a thickness of 1.2 mm or less as described in claim 4, and further reducing the weight of the vehicle body panel. Is possible.
[0037]
Further, according to the present invention, as described in claim 5, a so-called tailored blank material that is press-formed after the peripheral panel and the central panel are butt welded can be used for an inner panel, Inner panels can be made easier to use, such as using materials.
[0038]
Further, as described in claim 6, it is preferable that a selected panel among the panels constituting the vehicle body panel is made of an aluminum alloy. Since the aluminum alloy is lightweight and excellent in rigidity and formability, it is possible to further increase the rigidity, thickness and weight of the vehicle body panel.
[0039]
The convex portion provided on the central panel has a cone-shaped convex portion as described in claim 7, or the central panel has a substantially corrugated cross-sectional shape when a pedestrian's head collides. It is preferable in that the safety improvement effect is excellent.
[0040]
  Vehicle body panel of the present inventionLe walkApplicable to automobile hoods where travel protection is particularly requiredThe
[0041]
  AlsoTheIt is preferably applied to a hood for a moving vehicle, in which pedestrian protection is particularly difficult and the minimum distance between the engine room built-in inside the hood and the inner panel in the hood is 50 mm or less.
[0042]
Since the vehicle body panel of the present invention has excellent effects as described above, it can be used for vehicle body panels in general as vehicle body panels such as fenders, doors, and roofs in addition to automobile hoods.
[0043]
In the present invention, the cushioning material and / or the sound absorbing material is allowed to be disposed at an appropriate location on the back side of the outer panel within a range that does not hinder the weight reduction of the vehicle body panel.
[0044]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the above and the following explanations are based on automobile hoods.De andThe explanation focuses on protecting the head of a pedestrian during a crash.The
[0045]
First, an embodiment of an automobile hood panel will be described below with reference to FIGS. 1 is a perspective view showing a hood inner panel according to the present invention, FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1 (however, a cross section as a hood panel 8a in which an outer panel 7 is further provided on the inner panel), and FIG. 2 is a perspective view showing a state in which a hood panel 8a is attached to 20. FIG.
[0046]
In FIG. 1, the inner panel is basically composed of a central panel 1 in the inner panel and peripheral panels 3, 4, 5, 6 surrounding the central panel 1 from the periphery. . In FIG. 1, the peripheral panels 3, 4, 5, and 6 are illustrated as an example of a divided structure with the peripheral panel 3 at the front of the vehicle body. Yes. However, whether the peripheral panels 3, 4, 5, and 6 are all originally integrated panels, all the panels are divided, or any of the panels is divided is determined by the design of the vehicle body panel. It is appropriately selected depending on the manufacturing conditions.
[0047]
In FIG. 1, peripheral panels 3, 4, 5, 6 in the inner panel are respectively edge portions (flat portions) 3a, 4a, 5a, 6a, which are joint portions with an outer panel 7 described later, and a central portion. The edge portions (flat portions) 3b, 4b, 5b, 6b, which are joint portions with the panel, have a stepped shape. As described above, this peripheral panel gives the highest priority to compensating for the rigidity reduction of the central panel 1. For this purpose, the cross-sectional shape may be changed from the plate shape shown in FIG. 1 to an appropriate hollow shape such as a day shape, an eye shape, or a rice field to increase the rigidity. Further, a material having a higher proof stress is selected, or even if the same kind of material as that of the central panel is selected, a means for making the thickness of the peripheral panel thicker than that of the central panel is appropriately selected. Further, the peripheral panel also has an important role such as joining with the central panel 1 and the outer panel 7 to be integrated as a composite panel and exhibiting rigidity as a vehicle body panel. For this reason, the central panel 1 and the outer panel 7 and the joint are appropriately selected according to the joining means described later, in addition to the flat shape as shown in FIG.
[0048]
In FIG. 1, the center panel 1 and the peripheral panels 3, 4, 5, 6 are the edge of the center panel 1 and mechanical fastening means 10a, 10b, 10c such as bolts, nuts or self-piercing rivets. It is joined by. This joining is performed after the central panel 1 and the peripheral panels 3, 4, 5, and 6 are each molded, such as after molding to form a convex portion on the central panel 1. The joining means may be joined by an adhesive or welding (spot welding, FSW method), or a combination of these joining means and the mechanical joining means. A joining means is appropriately selected. Further, the joining location is also appropriately selected.
[0049]
Here, the central panel is provided with a plurality of convex portions whose tops are directed to the outer panel side at predetermined intervals in the vehicle width direction or the vehicle body direction. For example, in FIGS. 1 and 2, the central panel 1 is a convex part 2 with the top 2a facing the outer panel 7 side, and has a plurality of bead-like shapes having a corrugated cross section of the central panel 1 The convex portions 2 are provided extending in the longitudinal direction of the vehicle body at a predetermined interval in the vehicle width direction. The convex portion 2 has a concave and convex shape having a continuous cross-sectional waveform composed of the top portion 2a and the concave portion (interval portion) 2b. This convex part 2 is preferable in that the safety at the time of a pedestrian head collision is excellent among the convex parts.
[0050]
However, this convex portion may be replaced with the cone-shaped convex portion (conical truncated cone shape) shown in FIG. 10 that is excellent in safety at the time of a pedestrian head collision. This cone-shaped convex part has a hypotenuse (slope) with respect to the substantially flat top of the projection, unlike the convex part 2 that is continuous (continuous) in the shape of the bowl shown in FIGS. It consists of a group of convex portions having substantially the same or similar shape. And between each convex part (space | interval part) is a flat plate thru | or a recessed part.
[0051]
However, in addition to such convex portions, convex portions such as the bead type (including a case where the panel is not partially trimmed) and an embossed shape are also included in the scope of the present invention. In addition, a convex portion group in which the convex portions are partially connected, a convex portion group in which the size and shape such as the height and diameter of the convex portion are different depending on the part, and a convex portion group in which these are combined may be included as modified examples. Also, the slope side (cross-sectional) shape constituting the convex portion is appropriately selected as a slope shape such as an inclination angle, a straight line shape, a sigmode curve shape recessed downward, a convex curve bulging upward, or a combination thereof. Furthermore, the case where the convex portion has a vertical wall or a side wall having a substantially right angle is appropriately selected.
[0052]
Furthermore, in order to improve safety at the time of a pedestrian head collision, the convex shape to be provided is deformed from the basic shape of the cone-shaped convex portion or the cross-sectional wave-shaped convex portion, and at the time of a pedestrian head collision, one convex portion is formed. The shape may be more likely to cause local deformation (shock absorption). The convex part demonstrated above is obtained by shape | molding a panel base plate by press molding etc. FIG.
[0053]
Next, the function of these convex parts will be described. When the head of the pedestrian collides, the vehicle body panel is deformed to the inner side of the vehicle body panel due to the deformation of the outer panel and the inner panel. At the time of the collision, each of the convex portions is deformed so that the top portion of the convex portion itself is vertically crushed, and functions to absorb an impact caused by the collision between the vehicle body panel and the head.
[0054]
In order to exhibit this shock absorbing function, it is necessary that the top of the convex portion has a shape toward the outer panel side. In addition, the height of the convex part and the width of the convex part are increased so that the top part of the convex part itself is deformed to the maximum by the vertical collapse and the impact absorbing function is enhanced. It needs to be relatively large. Furthermore, the inner panel (center panel) needs to be formed with a plurality or a plurality at a predetermined interval so as to be able to cope with a pedestrian's head colliding with an arbitrary place on the vehicle body panel. is there.
[0055]
Note that the predetermined interval and arrangement (number, interval, etc.) conditions of the convex portions are appropriately selected from the pedestrian head collision possibility region and part to be exhibited, the impact absorbing function, the rigidity improvement effect, and the like. For example, it is not always necessary to provide the convex portion on the entire back surface of the center panel. That is, to protect the pedestrian head in the event of a collision, for example, a small part where the minimum distance between the engine compartment built-in hood and the hood inner panel is 50 mm or less, especially the head of a child or an adult. A part that needs to be improved in collision safety, such as a part that easily collides, can be selected and partially provided in the part. The convex portions to be provided may have the same or similar shapes, and the conditions (shape, size, etc.) of the convex portions described above can be changed according to the part where the head of a child or adult easily collides. is there.
[0056]
Furthermore, in this invention, it is good also considering the convex part of these center part panels as a shape which is easy to deform | transform from a viewpoint of a pedestrian's head protection. The shape design of the central panel convex portion from the viewpoint of protecting the pedestrian's head has not been considered in the convex shape of the conventional inner panel. More specifically, in the present invention, the inner panel can be divided and the overall rigidity of the peripheral panel can be improved. For this reason, contribution to the panel whole rigidity of a center part panel convex part can be reduced. Therefore, in this invention, the freedom degree of design spreads from a viewpoint of the pedestrian head protection of the convex part provided in a center part panel.
[0057]
As a result, the local rigidity of the central panel convex portion itself is reduced, and the convex portion is more easily deformed at the time of a pedestrian head collision with the outer panel corresponding to the convex portion. The reaction force to the part can be reduced. This can be achieved by changing the shape of the convex portion of the necessary portion of the convex portions arranged on the central panel to a shape that is more easily deformed, either entirely or partially. For example, the hypotenuse that constitutes the convex portion may be provided with a recess or notch that reduces the local rigidity of the convex portion itself and makes the convex portion easier to deform.
[0058]
Next, the vehicle body panel structure will be described. In the vehicle body panel (hood panel) 8a of the present invention shown in FIG. 2, the inner panel consisting of the central panel 1 and the peripheral panels 4 and 5 in FIG. 1 has a certain curvature according to the vehicle body design such as the hood. It is joined to the outer panel 7 and integrated as a composite panel (hood).
[0059]
In FIG. 2, a resin layer 9 is disposed on the top 2 a of the convex portion 2 of the central panel 1. The convex portion 2 of the central panel 1 and the back surface of the outer panel 7 are joined to each other through the resin layer 9. Further, the edge portions 4a and 5a of the peripheral panels 4 and 5 are integrated as a composite panel by fitting the peripheral edge portion 7a of the outer panel 7 by hem (bending) processing.
[0060]
FIG. 3 is a perspective view showing a state in which the composite panel of FIG. 2 is attached to the automobile 20 as an automobile hood (bonnet).
[0061]
Next, FIG. 4 is a perspective view showing a state in which the composite panel 8b of another embodiment is attached to the automobile 20 as an automobile hood. In FIG. 4, a central panel 1 which is an inner panel of the composite panel 8b has the same structure as that of FIG. However, the peripheral panel 12 is an integral panel that surrounds the central panel 1 from the periphery, and is thicker than the central panel thickness, further improving the overall rigidity of the inner panel and the hood panel. I am letting. And, as shown by the weld bead 13, the peripheral portion (joint portion) of each of the central panel 1 and the peripheral panel 12 is butt welded and integrated as an inner panel. Although not shown, the joining with the outer panel 7 is basically the same as in the case of FIG.
[0062]
The peripheral panel 12 and the central panel 1 may be a so-called tailored blank material that is press-molded after butt welding. In this case, the inner panel can be manufactured at a lower cost, such as the use of mill ends generated in the panel manufacturing process. In FIG. 4, 21 is a known (local) reinforcing member such as a hinge reinforcement or a latch reinforcement. The vehicle body panel of the present invention is allowed to be reinforced by appropriately using these known or existing reinforcing members.
[0063]
Next, a mode in which sound absorbing performance is further added to the vehicle body panel of the present invention will be described. In order to add sound absorbing performance to the vehicle body panel, a large number of through holes having a sound absorbing effect are directly provided in the central panel, or a large number of through holes having a sound absorbing effect are provided on the back surface of the central panel. Provide a sound absorbing panel.
[0064]
Usually, providing the convex part which is excellent in safety at the time of a pedestrian head collision with the inner panel is contradictory to providing the sound absorbing through hole, and therefore only one of them is provided. In fact, when the convex portion is formed after the sound absorbing through hole is provided in the flat inner panel material, the panel is cracked from the sound absorbing through hole as a starting point, or the sound absorbing through hole is crushed. The reason for this is that, as will be described later, the through hole for having a sound absorbing effect has a fine hole diameter, and in order to prevent the complexity of the process, the flat inner panel material is not preliminarily formed after the convex portion is formed. This is because it is necessary to provide it. Moreover, the molding conditions of the convex portion are also severe because the sound-absorbing through holes are easily crushed.
[0065]
However, in the present invention, as described above, the projection of the center panel can be easily molded and the molding conditions of the projection can be relaxed. Therefore, when the projection is molded, the panel may be cracked starting from the sound absorbing through hole. In addition, it is possible to mold without crushing the through hole. For this reason, both the convex part which is excellent in the safety | security at the time of a pedestrian head collision, and many through-holes which have a sound absorption effect can be provided with respect to an inner panel.
[0066]
FIG. 5 shows simultaneously a mode in which a sound absorbing through hole is provided in the central panel, which is an inner panel, and a mode in which a sound absorbing panel in which the sound absorbing through hole is provided is provided on the back surface of the central panel. FIG. 5 shows a cross section in the width direction of the vehicle body panel 8c, and reference numeral 15a denotes a number of sound absorbing through holes provided in the central panel (however, only shown in the figure when only a part is provided). Reference numeral 14 denotes a sound absorbing panel provided with a large number of sound absorbing through holes 15b, which is provided on the back surface of the central panel 1. The composite panel configuration of the vehicle body panel 8c other than the sound absorption panel 14 and the sound absorption through hole 15b is basically the same as the vehicle body panel 8a of FIG.
[0067]
The sound absorbing panel 14 is provided on the back surface of the central panel 1 by mechanical means such as bolts, nuts or self-piercing rivets (not shown) on the back surface (back surface of the spacing portion) of each flat portion 2c of the convex portion 2 of the central panel 1. These are joined together by appropriate joining means such as a simple joining means, an adhesive means, or a welding means. When the sound absorbing through hole 15a is provided in the center panel 1, the sound absorbing through hole 15a is formed in the flat panel by machining, and then the convex portion 2 is formed.
[0068]
In order to further improve the rigidity of the sound absorbing panel and the overall rigidity of the vehicle body panel, it is preferable that the end of the sound absorbing panel is also joined to the outer panel. FIG. 5 also shows this aspect, and the end of the sound absorbing panel 14 is joined to the peripheral panels 4 and 5 and indirectly to the outer panel 7. Further, the sound absorbing panel itself may be a flat plate or a cross-sectional shape provided with unevenness.
[0069]
In this way, by providing a large number of through holes having a sound absorbing effect in the center panel or by providing a sound absorbing panel having a large number of through holes having a sound absorbing effect, if the hood of an automobile, such as an engine inside the hood A through hole having a sound absorbing effect is arranged on the front surface with respect to the sound source. As a result, it is possible not only to protect the pedestrian head at the time of collision, but also to give the vehicle body panel a sound absorbing effect on the sound source inside the panel. That is, in the case of an automobile hood, the sound absorption effect can be obtained in which the engine sound inside the hood is absorbed and reduced to make the vehicle travel comfortable. Further, when the sound absorbing panel is provided, the vehicle body panel itself is also reinforced.
[0070]
The sound absorption effect of this through hole is determined by the thickness and diameter of the panel in which the through hole is provided, the distribution area of the through hole (installation area of the sound absorbing panel), and the thickness of the air layer (space) on the front surface of the through hole (side surface of the outer panel). . As the panel plate thickness increases, the through-hole diameter decreases, the through-hole distribution area increases, and the air layer (space) on the front surface of the through-hole (outer panel side surface) increases, the sound absorption effect such as the engine sound becomes greater. high.
[0071]
In this regard, in the sound absorbing panel 14 of FIG. 5, the space 2d in the convex portion 2 of the central panel 1 forms an air layer in front of the through hole 15b. In other words, when the sound absorbing panel is provided with a number of through holes to provide a sound absorbing effect, the sound absorbing panel is joined to the central panel so that the space (air layer) is provided in the convex portion of the central panel. There is a need. When a large number of through holes 15a having a sound absorbing effect are provided in the central panel 1, the space between the back surface of the outer panel 7 and the convex portion 2 forms an air layer on the front surface of the through hole 15a.
[0072]
However, the panel thickness and installation area of the panel are in balance with the suppression of the weight increase of the body panel, and the air layer thickness in front of the through hole is the design condition of the body panel thickness and the distance between the body panel and the built-in components. It is also determined in consideration of the design conditions. Considering these, it is preferable that the hole diameter of the sound absorbing through hole is Φ3 mm or less, preferably Φ1 mm or less, and the total opening ratio of the through holes to be provided is 1 to 5% with respect to the surface area (one side) of the sound absorbing panel. .
[0073]
In addition, in order to increase the sound absorbing effect of the sound absorbing through hole, sound absorbing materials such as glass wool and felt may be provided in layers at appropriate positions on the back surface of the central panel and the back surface of the sound absorbing panel. For example, in the past, when a sound absorbing material is provided on the back surface of the hood inner, it is usually necessary to provide a thickness of at least 10 mm or more in order to exert a sound absorbing effect. However, in the sound absorbing panel, it is not necessary to newly provide a sound absorbing material, and even when a sound absorbing material is provided, the sound absorbing panel can be made as thin as several millimeters.
[0074]
Further, the through hole is not necessarily provided on the entire surface of the central panel or the sound absorbing panel, and may be limited to a portion that requires sound absorption. For example, in FIG. 5, the through-hole is not provided in the joint portion with the central panel 1, and the joint strength of this portion is ensured, and the sound absorbing panel corresponding to the convex portion 2 (bottom surface) of the central panel 1 is secured. A through hole may be provided only in the 14 region.
[0075]
  The material used in the vehicle body panel of the present invention includes an outer panel, an inner panel, and a sound absorbing panel, other than an aluminum alloy.Steel plateMay be used. AThe outer panel may be a steel plate or an aluminum alloy plate, and the inner panel may be an aluminum alloy plate having a convex portion of the present invention, and the outer and inner materials may be changed. However, the weight and rigidity of the pedestrian and pedestrian protection are particularly required.DoIt is particularly preferable to use an aluminum alloy plate for the vehicle body panel.
[0076]
Among these aluminum alloy plates, especially for inner panel thin plate materials of 1.2 mm or less, Al-Mg-Si (6000 series) can be reduced in weight in terms of high formability and high strength (high proof stress). ) And Al-Mg (5000 series) aluminum alloy plates are particularly preferred. However, as long as the required panel characteristics are satisfied, various aluminum alloy plates such as 3000 series and 7000 series may be used.
[0077]
Further, according to the present invention, it is allowed to dispose a cushioning material and a sound absorbing material at appropriate locations on the back side of the outer panel within a range that does not hinder weight reduction of the vehicle body panel. The back side of the outer panel is, for example, the space between the outer panel and the inner panel, the back side of the inner panel, or the like.
[0078]
Next, the inner panel of the present invention shown in FIGS. 1 and 2 described above, where the pedestrian head is h₁ (Convex top 2a, invention example 1), h₂The analysis results of the load-displacement curve when it collides with each other (projection spacing 2c, invention example 2) are shown in Fig. 8, with long dotted lines (h₁Invention Example 1) and a short dotted line (h₂This is shown in Invention Example 2). As a premise, the minimum distance between the engine compartment built-in inside the hood and the hood inner panel is 30 mm. For comparison, the conventional beam-type inner panel shown in FIG. 9 is shown as a solid line in the conventional example described above, and in the case of this beam-type inner panel, the minimum distance between the built-in object inside the vehicle body panel and the inner panel ( Even when the clearance is increased to 80 mm, it is indicated by a dashed line.
[0079]
Although FEM analysis was used for the analysis, the actual body panel structure is complex and cannot be easily modeled. For this reason, both the inner panel splitting (joining) structure shown in FIGS. 1 and 2 of the invention example and the conventional beam type inner panel shown in FIG. The panel structure has been greatly simplified to provide a simplified model for grasping the trend of HIC values. The analyzed outer panel and inner panel were the same 6061-T4 aluminum alloy plate.
[0080]
As can be seen from Fig. 8, the load-displacement curve of the conventional beam-type inner panel (conventional example) in Fig. 9 shows the peak of the first wave at the beginning of the collision (load) depending on the progress (stroke) of time (panel deformation). Following P1, at the peak P2 of the second wave, the load (reaction force on the head) is greatly increased. For this reason, it is inevitably predicted that the HIC value cannot be less than 1000.
[0081]
On the other hand, all of the invention examples can reduce the load (reaction force against the head) in the peak P2 region of the first wave and particularly the second wave as compared with the conventional example. Therefore, according to the present invention, even if the pedestrian's head collides with either the top of the convex portion or the interval between the convex portions, or the pedestrian's head collides with a portion where the interval is small. It can be seen that the HIC value can be reduced to 1000 or less, and the safety of pedestrians can be secured in the event of a head collision.
[0082]
【The invention's effect】
  According to the present invention, in the vehicle body panel provided with the inner panel, even if any (arbitrary) part of the vehicle body panel collides with the pedestrian's head, the pedestrian's head is placed in the part where the interval is small. Even if it collides, it has excellent collision safetyBody panel for automobile hoodCan be provided. In addition, it is possible to provide a vehicle body panel that can ensure the safety at the time of a pedestrian's head collision even if the minimum distance between the built-in object inside the hood and the inner panel is small. For this reason, the HIC value was reduced to ensure the safety of pedestrians during head collisions.Body panel for automobile hoodCan be provided. Moreover, these effects can be achieved without increasing the cost, and the industrial value is great.
[Brief description of the drawings]
FIG. 1 is a perspective view showing one embodiment of a hood inner panel according to the present invention.
2 is a cross-sectional view taken along the line AA in FIG. 1 (however, a cross section as a hood panel 8a in which an outer panel 7 is further provided on the inner panel is shown).
FIG. 3 is a perspective view showing an aspect in which a hood panel according to the present invention is attached to a vehicle body.
FIG. 4 is a perspective view showing another aspect of the vehicle body panel of the present invention.
FIG. 5 is a cross-sectional view showing another aspect of the vehicle body panel of the present invention.
FIG. 6 is a perspective view showing an analysis model of a vehicle body panel according to the present invention.
FIG. 7 is an explanatory diagram generally showing a relationship (load-displacement curve) between acceleration to the head and time at the time of head collision.
FIG. 8 is an explanatory diagram showing a relationship (load-displacement curve) between acceleration to the head and time at the time of head collision in the embodiment.
FIG. 9 is a perspective view showing a conventional beam type inner panel.
FIG. 10 is a perspective view showing a conventional cone-type inner panel.
[Explanation of symbols]
1: Center panel of inner panel, 2: Projection,
3, 4, 5, 6, 12: Peripheral panel of the inner panel, 7: Outer panel,
8: Body panel, 9: Resin layer, 10: Fastening means, 11: Contents such as engine,
13: Weld bead, 14: Sound absorbing panel, 15: Sound absorbing through hole,
16: Beam type inner panel, 17: Beam, 18: Cone type inner panel,
19: Cone-shaped convex part, 20: Car body, 21: Hinge reinforcement,
22: Latch reinforcement

Claims (8)

In the outer panel body panel back surface sheet steel or aluminum alloy Lee N'napaneru to have been joined, the inner panel is a peripheral panel and the central panel is configured integrally joined to the periphery panel outer panel with each other together are joined at the periphery of an automobile hood in the central panel excellent in the safety of at pedestrian head collision you wherein the protrusion top portion toward the outer panel side is formed use car body panel.   2. The sound absorbing panel according to claim 1, wherein a plurality of through holes having a sound absorbing effect are provided in the central portion panel and / or a sound absorbing panel having a plurality of through holes having a sound absorbing effect is provided on the back surface of the central portion panel. Body panel.   The body panel according to claim 1 or 2, wherein the peripheral panel plate thickness is thicker than the central panel plate thickness.   The vehicle body panel according to any one of claims 1 to 3, wherein a thickness of the central panel is 1.2 mm or less.   The vehicle body panel according to any one of claims 1 to 4, wherein the peripheral panel and the central panel are butt welded and then press-molded to form an inner panel.   The vehicle body panel according to any one of claims 1 to 5, wherein a selected one of the panels is made of an aluminum alloy.   The vehicle body panel according to any one of claims 1 to 6, wherein the central panel has a cone-shaped convex portion and / or has a substantially corrugated cross-sectional shape. The vehicle body panel according to any one of claims 1 to 7, wherein a minimum distance between the engine room built-in part in the hood and the central panel in the hood is 50 mm or less .

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