Patent Description:
Known in the past has been a reinforcing structure provided with first members arranged adjoining an outer panel of an automobile and extending in a first direction and second members extending in a second direction different from the first direction and crossing the first members (for example, see PTL <NUM>).

According to the art described in the above PTL <NUM>, due to the first members and second members provided in a lattice configuration, even without sufficient space, it is possible to absorb impact at the time of a collision. However, if considering the rising awareness about safety in recent years, it is preferable to improve the performance in absorption of an impact load more.

In the reinforcing structure disclosed in the above PTL <NUM>, if trying to further improve the performance in absorption of an impact load, for example, it may be considered to make the first members or the second members thicker or to use as the material of the first members and the second members a high strength one. However, making the first members or the second members thicker is disadvantageous on the point that the space efficiency becomes poorer, while using as the material of the first members or second members a high strength one is disadvantageous on the point that the workability becomes poorer. For this reason, it is sought to make the impact performance better by adding a different configuration from the first members and second members.

Therefore, the present invention has as its object to provide a reinforcing structure of an automobile exterior panel improving the performance in absorption of an impact load.

The reinforcing structure of an automobile exterior panel according to the present invention exhibits the advantageous effect that it is possible to improve the performance in absorption of impact loads.

First, referring to <FIG>, the configuration of an exterior panel of an automobile according to one embodiment of the present invention will be explained. <FIG> is a schematic view showing an inside of an exterior panel <NUM> of an automobile according to one embodiment in a state seen from a back side (vehicle inner side of automobile). Here, a door panel is illustrated as the exterior panel <NUM>, but the exterior panel <NUM> may also be a panel of a fender, hood, roof, rear gate, or other member of an automobile.

As shown in <FIG>, the exterior panel <NUM> has an outer panel (exterior material) <NUM> and reinforcing members <NUM>. The outer panel <NUM> is comprised from a steel sheet of a thickness of <NUM> or so as one example. The outer panel <NUM> is curved so that its front side (vehicle outer side of automobile) becomes a convex surface. Further, the curvature of the curve runs along the vertical direction.

The reinforcing members <NUM> include first reinforcing members <NUM> of long shapes arranged in the vertical direction and second reinforcing members <NUM> of long shapes arranged in the horizontal direction. Note that, a "long shape" means a shape having a length extending in a predetermined direction and in particular means a shape extending in a predetermined direction by a length larger than a maximum value of an external dimension of a cross-section perpendicular to that predetermined direction. Further, the first reinforcing members <NUM> and the second reinforcing members <NUM> are all long shapes, but need not be configured from single members across the entire regions in the vertical direction or horizontal direction. For example, the first reinforcing members <NUM> or second reinforcing members <NUM> may also be comprised from pluralities of members of long shapes split at the positions of crossing parts C where the two cross. The first reinforcing members <NUM> are preferably curved matching the curvature of the outer panel <NUM>. The second reinforcing members <NUM> extend substantially straight, but if the outer panel <NUM> is curved, they are preferably shaped matching the curve. The first reinforcing members <NUM> and the second reinforcing members <NUM> can closely contact the outer panel <NUM> if shaped matching the outer panel <NUM> and preferably can be joined with (bonded with) the outer panel <NUM>.

<FIG> is a perspective view showing the configuration of a reinforcing member <NUM>. The basic configurations of the first reinforcing members <NUM> and the second reinforcing members <NUM> can be made the same, but as explained later, either of the first reinforcing members <NUM> and the second reinforcing members <NUM> are made higher in rigidity than the other. As one example, the reinforcing member <NUM> has a hollow box shaped (rectangular shaped) cross-section. The reinforcing member <NUM> is produced by bending a sheet material <NUM>. In the example shown in <FIG>, the reinforcing member <NUM> has a rectangular cross-sectional shape. Among the sides, the long sides are <NUM> or so and the short sides are <NUM> or so. Further, the thickness of the sheet material <NUM> forming the reinforcing member <NUM> is, as one example, <NUM> or so. As the sheet material <NUM>, a steel sheet can be used.

As shown in <FIG>, between an end part 130a and an end part 130b of the bent sheet material <NUM>, a predetermined gap may be provided. On the other hand, the end part 130a and the end part 130b may also be in close contact. Further, the end part 130a and the end part 130b may also be joined by welding, bonding, etc. The reinforcing member <NUM> is arranged so that the surface at which the end parts 130a and 130b are positioned or the surface at the opposite side to the surface at which the end parts 130a and 130b are positioned is in close contact with the outer panel <NUM>. Preferably, the surface at which the end parts 130a and 130b are positioned or the surface at the opposite side to the surface at which the end parts 130a and 130b are positioned is joined with the outer panel <NUM>.

Here, the surface which is joined with or adjoins the outer panel <NUM> will be called the "bottom surface". Further, the surface at the opposite side to the bottom surface will be called the "top surface". The surfaces positioned at the two sides of the bottom surface across the ridges will be called the "vertical walls". In the cross-section of the reinforcing member <NUM>, the lower short side is the bottom surface and the long sides are the vertical walls. In a configuration where the end parts 130a and 130b are arranged at the top surface without being joined, if pushed from the outside direction of the exterior panel <NUM> and the reinforcing member <NUM> is curved, the cross-section opens from the end parts 130a and 130b and the cross-sectional shape easily collapses. However, if the end parts 130a and 130b are joined, it is possible to prevent the cross-sectional shape from collapsing, so it becomes possible to raise the rigidity of the exterior panel <NUM> more. Even if the end parts 130a and 130b are arranged at the bottom surface and the bottom surface is joined with the outer panel <NUM>, it is possible to prevent the end parts 130a and 130b from separating due to the outer panel <NUM> and the cross-sectional shape from collapsing.

As shown in <FIG>, in a horizontal cross-sectional perpendicular to the longitudinal direction of the reinforcing member <NUM>, if designating a short side of the rectangle as the "width (D)" and a long side as the "height (H)", the reinforcing member <NUM> has a height H in a direction perpendicular to the surface of the outer panel <NUM> larger than the width D in a direction along the outer panel <NUM>. Due to this, if an impact load is applied on the exterior panel <NUM> from the vehicle outer side to the inner side direction, the cross-sectional secondary moment of the reinforcing member <NUM> can be effectively improved. Further, by the cross-sectional secondary moment of the reinforcing member <NUM> being improved, the exterior panel <NUM> according to the present embodiment can be improved in impact resistance performance.

Note that, the cross-sectional configuration of the reinforcing member <NUM> is not limited to a configuration like in <FIG> where the end parts 130a and 130b face each other. For example, it may also be a groove type (channel) shape where the end parts 130a and 130b are separated or a hat shape. Further, the reinforcing member <NUM> may also be configured not from a hollow but a solid member. Regarding the material of the reinforcing member <NUM>, it is also possible to use another metal material other than a steel sheet such as aluminum. A plastic material etc. may also be used.

<FIG> is a schematic view showing the state of the exterior panel <NUM> seen from the front side. For explanation, in <FIG>, the outer panel <NUM> is cut away to show the internal structure of the exterior panel <NUM>. The exterior panel <NUM> has, in addition to the outer panel <NUM> and the reinforcing members <NUM>, support members <NUM> for supporting the reinforcing members <NUM> from the vehicle inner side and an inner panel <NUM>.

<FIG> is a schematic view showing a cross-section along the one-dot chain line I-I' in <FIG>. As shown in <FIG>, in order from the front surface of the exterior panel <NUM>, the outer panel <NUM>, reinforcing members <NUM>, support members <NUM>, and inner panel <NUM> are arranged in that order. Note that, further inside the inner panel <NUM>, interior parts of the automobile (not shown) are arranged. The end parts of the first reinforcing members <NUM> and the second reinforcing members <NUM> are fixed to the inner panel <NUM> between the outer panel <NUM> and inner panel <NUM>.

In the example shown in <FIG>, the support members <NUM> are provided at the crossing parts C of the first reinforcing members <NUM> and the second reinforcing members <NUM>. The support members <NUM> are comprised of tube-shaped members with axial centers running from the front side toward the back side of the exterior panel <NUM>. The support members <NUM> are welded to the inner panel <NUM> at flanges <NUM> provided at the inner panel <NUM> side.

Note that, in <FIG>, the support members <NUM> do not necessarily have to be provided at all of the crossing parts C. The support members <NUM> may be provided at only some of the crossing parts C among the plurality of the crossing parts C where the first reinforcing members <NUM> and the second reinforcing members <NUM> cross. The number of the support members <NUM> can be suitably set in accordance with the envisioned impact absorption ability of the exterior panel <NUM>.

The end part of a support member <NUM> at the reinforcing member <NUM> side is close to or in contact with the surface of a reinforcing member <NUM> at the back side (vehicle inner side). The support member <NUM> is not fixed to the reinforcing member <NUM> but is unconstrained with respect to the reinforcing member <NUM>. Preferably, the end part of the support member <NUM> at the reinforcing member <NUM> side and the reinforcing member <NUM> are separated from each other. A gap is provided between the two. On the other hand, the support member <NUM> may also be fixed to the reinforcing member <NUM> by welding etc..

<FIG> is a perspective view showing one example of the configuration of a support member <NUM>. As shown in <FIG>, the support member <NUM> is configured in a cylindrical shape and is provided with a flange <NUM> at one end in the axial center direction. For example, the body of the support member <NUM> is comprised of a cylindrical pipe. The flange <NUM> may be configured integrally with the cylindrical body of the support member <NUM> or may be configured from a separate part joined with the body. The support member <NUM> is fixed to the inner panel <NUM> by being welded at the welded part <NUM> of the flange <NUM> (spot welding or arc welding). Note that, the support member <NUM> may also be attached to the inner panel <NUM> by riveting, bonding, bolting, or other means. The support member <NUM>, like the reinforcing members <NUM>, is comprised of a steel material, aluminum, or other metal material and may be comprised of a plastic material etc..

<FIG> is a perspective view showing one example of the configuration of a crossing part C of the first reinforcing member <NUM> and the second reinforcing member <NUM> in <FIG> and shows the state when viewing the crossing part C from the vehicle outer side. Further, <FIG> is a schematic view showing the state where the first reinforcing member <NUM> and the second reinforcing member <NUM> are separated at the crossing part C. As shown in <FIG>, at the position of the crossing part C, the second reinforcing member <NUM> is positioned at the vehicle outer side (outer panel <NUM> side) with respect to the first reinforcing member <NUM>. Further, as shown in <FIG>, the first reinforcing member <NUM> is provided with a recessed part 122a while the second reinforcing member <NUM> is provided with a recessed part 124a. For this reason, if assembling the first reinforcing member <NUM> and the second reinforcing member <NUM> so that the recessed part 122a and the recessed part 124a abut at the crossing part C, the surfaces of the first reinforcing member <NUM> and the second reinforcing member <NUM> at the vehicle outer side and the vehicle inner side become generally flush.

In the present embodiment, if an impact load is applied from the vehicle outer side, the roles which the first reinforcing member <NUM> and the second reinforcing member <NUM> perform differ. The first reinforcing member <NUM> and the second reinforcing member <NUM> differ in rigidity even if the same in thickness due to the differences in lengths at the exterior panel <NUM> and extents of curvature. For example, if the exterior panel <NUM> is a door panel, since a door panel is usually a shape laterally long in the horizontal direction, the first reinforcing member <NUM> is shorter than the second reinforcing member <NUM>. Therefore, if considering the first reinforcing member <NUM> and the second reinforcing member to be beams with two fixed ends, the shorter length first reinforcing member <NUM> becomes higher in rigidity if an impact load is applied compared with the longer length second reinforcing member <NUM>. Therefore, for receiving the impact load and absorbing the impact, the first reinforcing member <NUM> is more suitable than the second reinforcing member <NUM>.

Further, if the first reinforcing member <NUM> is curved so as to project out to the vehicle outer side matching the curvature of the outer panel <NUM>, if an impact load is applied from the vehicle outer side, the first reinforcing member <NUM> will be crushed upon receiving compressive force in the longitudinal direction. On the other hand, the second reinforcing member <NUM>, which has little curvature, receives almost no compressive force in the longitudinal direction if an impact load is applied from the vehicle outer side. Therefore, the first reinforcing member <NUM> is superior in impact resistance performance compared with the second reinforcing member <NUM> due to being crushed when an impact load is applied.

For this reason, by making the first reinforcing member <NUM>, which is higher in rigidity and more suitable for impact absorption, thicker than the second reinforcing member <NUM>, it is possible to further raise the rigidity of the first reinforcing member <NUM> and more effectively absorb impact. In other words, by making the first reinforcing member <NUM> thicker than the second reinforcing member <NUM>, it is possible to make the first reinforcing member <NUM>, which is better in impact resistance performance both in terms of dimensions and shape, the main means for absorption of the impact load.

Note that, the first reinforcing member <NUM> being "thicker" than the second reinforcing member <NUM> means the first reinforcing member <NUM> being larger than the second reinforcing member <NUM> in the area at the inside from the contour of the member in the cross-section (transverse section) perpendicular to the longitudinal direction of the first reinforcing member <NUM> or second reinforcing member <NUM>. For example, if the transverse section of the first reinforcing member <NUM> and second reinforcing member <NUM> is a hollow rectangular shape such as shown in <FIG>, the first reinforcing member <NUM> being "thicker" than the second reinforcing member <NUM> means the first reinforcing member <NUM> being larger than the second reinforcing member <NUM> in the area expressed by DxH shown in <FIG>.

Alternatively, if the transverse section of the first reinforcing member <NUM> and second reinforcing member <NUM> is a hollow rectangular shape such as shown in <FIG>, the first reinforcing member <NUM> being "thicker" than the second reinforcing member <NUM> means the first reinforcing member <NUM> being larger than the second reinforcing member <NUM> in one or both of the width D or height H shown in <FIG>.

On the other hand, the second reinforcing member <NUM> has the function of transferring an impact load applied to the exterior panel <NUM> from the outside to the first reinforcing member <NUM>. For this reason, in the example of the configuration shown in <FIG>, at the crossing part C, the second reinforcing member <NUM> is positioned further at the vehicle outer side than the first reinforcing member <NUM>.

Therefore, if an impact load is applied to the exterior panel <NUM> from the vehicle outer side, the impact load is first transferred from the outer panel <NUM> to the reinforcing member <NUM>. The reinforcing member <NUM> arranged adjoining the outer panel <NUM> receives the impact load. At this time, at the crossing part C, since the second reinforcing member <NUM> is arranged further at the vehicle outer side than the first reinforcing member <NUM>, the impact load is transferred from the outer panel <NUM> to the second reinforcing member <NUM> between the adjacent first reinforcing members <NUM>, then is transferred to the first reinforcing member <NUM>. The first reinforcing member <NUM> is higher in rigidity than the second reinforcing member <NUM> and is crushed if an impact load is applied, so it is possible to effectively absorb an impact load by the first reinforcing member <NUM>.

If in the above way forming a reinforcing member <NUM> by making two reinforcing members cross, the lower rigidity reinforcing member is arranged at the vehicle outer side and the higher rigidity reinforcing member is arranged at the vehicle inner side. Due to this, when an impact load is applied from the vehicle outer side, the impact load is transferred from the lower rigidity reinforcing member to the higher rigidity reinforcing member and the impact load can be reliably absorbed by the higher rigidity reinforcing member. Further, by making the rigidity of the reinforcing member at the vehicle outer side comparatively low, it is possible to provide an exterior panel <NUM> which maintains the required strength while being made lighter in weight.

Further, in the present embodiment, a support member <NUM> is provided for supporting a reinforcing member <NUM> from the vehicle inner side. If a reinforcing member <NUM> receiving the impact load deforms to the vehicle inner side, the reinforcing member <NUM> abuts against the end part of the support member <NUM> at the reinforcing member <NUM> side and the impact load is transferred to the support member <NUM>. The flange <NUM> of the support member <NUM> is fixed to the inner panel <NUM>, so the impact load is absorbed by the support member <NUM> receiving the impact load being crushed. The support member <NUM> is a tube-shaped member with an axial center extending from the vehicle outer side to the vehicle inner side, so is easily crushed when receiving an impact load resulting in a higher impact absorption ability.

Therefore, according to the present embodiment, in addition to the absorption of an impact load by the reinforcing member <NUM>, it is possible to absorb an impact load by the support member <NUM>, so the impact resistance performance of the exterior panel <NUM> can be greatly improved. Note that, as explained above, preferably a gap is provided between the end part of the support member <NUM> at the reinforcing member <NUM> side and the reinforcing member <NUM>. Due to this, when an impact load is applied from the vehicle outer side, the impact load is absorbed by the reinforcing member <NUM> before the reinforcing member <NUM> abuts against the end part of the support member <NUM> at the reinforcing member <NUM> side, then the support member <NUM> is crushed, whereby the impact load is absorbed. On the other hand, when not providing a gap between the end part of the support member <NUM> at the reinforcing member <NUM> side and the reinforcing member <NUM>, the impact load is directly applied to the support member <NUM>. In that case, if the impact load cannot be sufficiently absorbed by the support member <NUM>, there is a possibility of the inner panel <NUM> deforming to the compartment side. By providing a gap between the end part of the support member <NUM> at the reinforcing member <NUM> side and the reinforcing member <NUM>, the empty running distance until the reinforcing member <NUM> abuts against the end part of the support member <NUM> is secured and the impact load is absorbed in two stages at both of the reinforcing member <NUM> and the support member <NUM>, so the inner panel <NUM> is kept from deforming to the compartment side.

Note that, the thickness of the tube-shaped member of the support member <NUM> is preferably made a value of an extent whereby the support member <NUM> is suitably crushed when an impact load is applied.

The support member <NUM> can be arranged at various positions with respect to the reinforcing member <NUM>. In the example shown in <FIG>, by providing the support member <NUM> at the crossing part C where the first reinforcing member <NUM> and the second reinforcing member <NUM> cross, it is possible to absorb the impact by both the impact absorbing performance at the crossing part C where the first reinforcing member <NUM> and the second reinforcing member <NUM> cross and the impact absorbing performance of the support member <NUM> and raise the impact resistance performance.

Specifically, as explained above, the first reinforcing member <NUM> mainly absorbs the impact load, but the second reinforcing member <NUM> passing through the crossing part C also contributes to impact absorption by deforming to the vehicle inner side. Therefore, by providing the support member <NUM> at the crossing part C, in addition to the impact absorption ability of the first reinforcing member <NUM> and the second reinforcing member <NUM> at the crossing part C, impact absorption using the impact absorption ability of the support member <NUM> becomes possible.

To enable the support member <NUM> to reliably support the reinforcing member <NUM>, it is important that the end part of the support member <NUM> at the reinforcing member <NUM> side reliably support the reinforcing member <NUM> if an impact load is applied. For this reason, in the present embodiment, a predetermined relationship is given between the width of the support member <NUM> and the width of the reinforcing member <NUM> so that the end part of the support member <NUM> at the reinforcing member <NUM> side always supports the reinforcing member <NUM>.

<FIG> is a plan view showing the state of the crossing part C seen from the vehicle outer side. As shown in <FIG>, a diameter A of the end part of the support member <NUM> at the reinforcing member <NUM> side is larger than a width D of the first reinforcing member <NUM> or second reinforcing member <NUM>, preferably is made <NUM> times or more the width D. By making the diameter A of the support member <NUM> larger than the width D, it is possible to reliably transfer the impact load from the crossing part C to the support member <NUM>. Further, by making the diameter A <NUM> times or more of the width D, even if the position of the crossing part C shifts in the vertical direction or horizontal direction along the surface of the outer panel <NUM> when receiving an impact load, it is possible to reliably transfer the impact load from the crossing part C to the support member <NUM> without the position of the crossing part C seen in the direction from the vehicle outer side toward the vehicle inner side from leaving the region where the cylinder of the support member <NUM> is present. Note that, as explained later, if configuring the support member <NUM> by a polygonal tube or hexagonal tube etc., it is configured so that the outer dimension (maximum width) of the end part of the support member <NUM> at the reinforcing member <NUM> side seen in the direction from the vehicle outer side toward the vehicle inner side becomes larger than the width D of the first reinforcing member <NUM> or second reinforcing member <NUM>, preferably <NUM> times or more of the width D.

Next, the configuration for preventing interference between the support member <NUM> and window glass <NUM> will be explained. <FIG> is a schematic view showing a cross-section along the one-dot chain line II-II' in <FIG>. In <FIG>, the window <NUM> provided at the exterior panel <NUM> is provided with a window glass <NUM>. By the window glass <NUM> descending, the window <NUM> opens.

When the window glass <NUM> descends, the bottom end of the window glass <NUM> does not reach the position of the one-dot chain line I-I' in <FIG>. Therefore, at the position of the one-dot chain line I-I', the window glass <NUM> does not interfere with the support member <NUM> so a structure preventing interference between the support member <NUM> and the window glass <NUM> becomes unnecessary.

On the other hand, when the window glass <NUM> descends, the window glass <NUM> reaches the position of the one-dot chain line II-II' of <FIG>. The support member <NUM> is provided between the reinforcing member <NUM> and the inner panel <NUM>. There is space for the window glass <NUM> to pass when the window glass <NUM> descends between the reinforcing member <NUM> and the inner panel <NUM>. For this reason, at the position of the one-dot chain line II-II', a structure where the window glass <NUM> does not interfere with the support member <NUM> becomes necessary.

For this reason, the structure is made one making the length of the support members <NUM> at the position of the one-dot chain line II-II' shorter than the length at the position of the one-dot chain line I-I' and thereby preventing the window glass <NUM> from interfering with the support members <NUM> when making the window glass <NUM> descend.

As shown in <FIG>, at the position of the one-dot chain line II-II', the end parts of the support members <NUM> at the reinforcing member <NUM> side do not reach the reinforcing members <NUM> and other support members <NUM> are provided at the vehicle outer side from the support members <NUM>. The support members <NUM> are made tube-shaped members similar to the support members <NUM>. They are provided so as to overlap the support members <NUM> at the positions of the crossing parts C. The support members <NUM> are fixed to the reinforcing members <NUM> by welding etc..

The vehicle inner sides of the support members <NUM> are provided with flanges <NUM>. Further, a gap "g" is provided between the end parts of the support members <NUM> at the reinforcing member <NUM> side and the flanges <NUM> of the support members <NUM>.

As explained above, the support members <NUM> are fixed to the inner panel <NUM> at the flanges <NUM> of the vehicle inner side, the support members <NUM> are fixed to the reinforcing members <NUM> at the end parts at the vehicle outer side, and a gap "g" is provided between the support members <NUM> and the support members <NUM>. According to such a configuration, when the window glass <NUM> descends, the window glass <NUM> can enter the gap "g", so it is possible to keep the window glass <NUM> and the support members from interfering.

Further, if an impact load is applied to the exterior panel <NUM> from the outside, if the reinforcing members <NUM> receiving the impact load deform to the vehicle inner side, the flanges <NUM> of the support members <NUM> fixed to the reinforcing members <NUM> abut against the end parts of support members <NUM> at the vehicle outer side and the impact load is transferred from the support members <NUM> to the support members <NUM>. The flanges <NUM> of the support members <NUM> are fixed to the inner panel <NUM>, so the support members <NUM> and the support members <NUM> receiving the impact load are crushed and thereby the impact load is absorbed. The support members <NUM> and the support members <NUM> are tube-shaped members with axial centers extending from the vehicle outer side to the vehicle inner side, so are easily crushed when receiving the impact load and increase the impact absorption ability. Note that, if the window glass <NUM> descends, the flanges <NUM> of the support members <NUM> abut against the end parts of the support members <NUM> at the vehicle outer side through the window glass <NUM>.

In the above way, according to the configuration of <FIG>, it is possible to provide the support members <NUM> and the support members <NUM> for absorbing the impact load without interference with the window glass <NUM> even at the position where the window glass <NUM> descends. Therefore, even at the position where the window glass <NUM> descends, if an impact load is applied to the exterior panel <NUM> from the vehicle outer side, it is possible to absorb impact by the support members <NUM> and the support members <NUM>.

In the configuration shown in <FIG>, the thicknesses of the support members <NUM> are formed smaller than the support members <NUM>, and the end parts of the support members <NUM> at the vehicle inner side are provided with flanges <NUM>. For this reason, if an impact load is applied, the flanges <NUM> of the support members <NUM> reliably abut against the end parts of the support members <NUM> at the vehicle outer side. Note that, the support members <NUM> are fixed to the reinforcing members <NUM>, so it is not necessary to consider positional offset of the reinforcing members <NUM> and the support members <NUM> when an impact load is applied. Therefore, the thickness of the support member <NUM> can be made smaller than the support members <NUM>.

In <FIG>, the example was shown where the support members <NUM> were arranged at positions of the crossing parts C where the first reinforcing members <NUM> and the second reinforcing members <NUM> cross, but the support members <NUM> can be provided at various positions and impact resistance performances corresponding to the layout positions can be obtained.

<FIG> show an example of arranging the support members <NUM> so as to support the first reinforcing members <NUM> between two adjoining crossing parts C.

<FIG>, like <FIG>, shows the exterior panel <NUM> in a state seen from the front side (vehicle outer side), while <FIG> is a schematic view showing a cross-section along the one-dot chain line III-III' in <FIG>.

As shown in <FIG>, if placing the support members <NUM> between two adjoining crossing parts C so as to support the first reinforcing members <NUM>, it is possible to raise the impact absorbing performance by the first reinforcing members <NUM> mainly receiving the impact load if an impact load is applied and the support members <NUM>.

As explained above, the first reinforcing members <NUM> are made higher in rigidity than the second reinforcing members <NUM> and mainly have the function of receiving the impact load. On the other hand, the second reinforcing members <NUM> have the function of transferring impact load from the second reinforcing members <NUM> to the first reinforcing members <NUM>.

For this reason, by supporting the first reinforcing members <NUM> configured so as to mainly receive the impact load between two adjoining crossing parts C by the support members <NUM>, it is possible to further raise the rigidity when the first reinforcing members <NUM> deform. Therefore, it is possible to further raise the impact absorbing performance by the first reinforcing members <NUM>.

Next, an exterior panel <NUM> raised in impact absorption ability with respect to an impact load in a direction along the outer panel <NUM> will be explained. For example, in the case like a door panel of an exterior panel <NUM> extending in the vehicle length direction, by making the second reinforcing members <NUM> extending in the vehicle length direction thicker, even if an impact load is applied in the vehicle length direction, the exterior panel <NUM> becomes harder to crush in the vehicle length direction. For this reason, by reversing the thicknesses of the first reinforcing members <NUM> and the second reinforcing members <NUM> and making the second reinforcing members <NUM> thicker than the first reinforcing members <NUM>, it is possible to better improve the impact absorption ability if an impact load is applied from the front side of the vehicle. Note that, it may also be configured to making the thickness of only the second reinforcing members <NUM> greater without reversing the thicknesses of the first reinforcing members <NUM> and the second reinforcing members <NUM>, but in this case, while it is possible to improve the impact absorption ability in the case where an impact load is applied from the front side of the vehicle, both the first reinforcing members <NUM> and the second reinforcing members <NUM> are thick, so the exterior panel <NUM> ends up increasing in weight.

On the other hand, as explained above, the second reinforcing members <NUM> are longer than the first reinforcing members <NUM> and less curved, so the relative rigidity easily becomes lower. Therefore, by just reversing the thicknesses of the first reinforcing members <NUM> and the second reinforcing members <NUM>, the impact absorption ability ends up falling in the case where an impact load is applied in a direction perpendicular to the surface of the outer panel <NUM>.

For this reason, if making the second reinforcing members <NUM> thicker than the first reinforcing members <NUM>, it is possible to supplement the rigidity of the second reinforcing members <NUM> by supporting the second reinforcing members <NUM> from the vehicle inner side by the support members <NUM>. Due to this, if an impact load is applied perpendicularly to the outer surface of the exterior panel <NUM>, it is possible to receive the impact load mainly by the second reinforcing members <NUM> which are thicker than the first reinforcing members <NUM> and possible to receive the impact load by the support members <NUM>. Therefore, by making the second reinforcing members <NUM> thicker than the first reinforcing members <NUM> and supporting the second reinforcing members <NUM> by the support members <NUM> from the vehicle inner side, it is possible to raise the impact absorption ability for both of the impact load in the horizontal direction along the surface of the outer panel <NUM> and the impact load in the direction perpendicular to the surface of the outer panel <NUM>.

As explained above, if configuring a reinforcing member <NUM> by making two reinforcing members cross, the lower rigidity reinforcing member is arranged at the vehicle outer side and the higher rigidity reinforcing member is arranged at the vehicle inner side. That is, among the first reinforcing members <NUM> and the second reinforcing members <NUM>, the members mainly receiving the impact load are preferably arranged at the vehicle inner side. For this reason, if making the second reinforcing members <NUM> thicker than the first reinforcing members <NUM>, at the crossing parts C, the second reinforcing members <NUM> are preferably arranged further to the vehicle inner side than the first reinforcing members <NUM>. Further, when supporting the second reinforcing members <NUM> by the support members <NUM>, by supporting the second reinforcing members <NUM> from the vehicle inner side at the crossing parts C where the first reinforcing members <NUM> and the second reinforcing members <NUM> cross, at the crossing parts C, it is possible to absorb impact utilizing both the impact absorption ability due to the rigidity of the first reinforcing members <NUM> and the second reinforcing members <NUM> and the impact absorption ability by the support members <NUM>.

From the above viewpoint, <FIG> show a configuration reversing the thicknesses of the first reinforcing members <NUM> and the second reinforcing members <NUM> from the configuration of <FIG> and making the second reinforcing members <NUM> thicker than the first reinforcing members <NUM>. Further, in the example shown in <FIG>, at the crossing parts C where the first reinforcing members <NUM> and the second reinforcing members <NUM> cross, the second reinforcing members <NUM> are arranged further to the vehicle inner side than the first reinforcing members <NUM>. Further, in the example shown in <FIG>, the support members <NUM> are arranged at the crossing parts C where the first reinforcing members <NUM> and the second reinforcing members <NUM> cross. <FIG>, like <FIG>, shows the exterior panel <NUM> in the state seen from the front side (vehicle outer side), while <FIG> shows a schematic view showing a cross-section along the one-dot chain line IV-IV' in <FIG>.

As explained above, by making the second reinforcing members <NUM> thicker than the first reinforcing members <NUM>, it is possible to increase the impact absorption ability with respect to the impact load in a direction along the outer panel <NUM>. Further, by supporting the second reinforcing members <NUM> by the support members <NUM>, it is possible to supplement the rigidity of the second reinforcing members <NUM>, so it is possible to absorb the impact load in a direction perpendicular to the outer panel <NUM> by mainly the second reinforcing members <NUM>.

Note that, in the configuration shown in <FIG>, support members <NUM> were placed at the crossing parts C where the first reinforcing members <NUM> and the second reinforcing members <NUM> cross, but the support members <NUM> may also be placed between the adjoining crossing parts C so as to support the second reinforcing members <NUM>.

Next, variations of the structure of the support members <NUM> will be explained. The support members <NUM> can be made various structures with tube-shaped members as the basic structures. <FIG> are schematic views showing variations in the shapes of the support members <NUM>. <FIG> is a schematic cross-sectional view showing a support member <NUM> with a flange <NUM> facing the reinforcing member <NUM> provided at an end part at the reinforcing member <NUM> side and shows a cross-section along the axial center of the support member <NUM>. Further, <FIG> is a perspective view showing the support member <NUM> shown in <FIG>. As shown in <FIG>, a flange <NUM> is provided at the end part at the opposite side from the flange <NUM> as well. The flange <NUM>, like the flange <NUM>, may be configured integrally with the tubular body of the support member <NUM> or may be configured from a separate part joined with the body.

According to the configuration shown in <FIG>, if an impact load is applied to the exterior panel <NUM>, it is possible to receive the reinforcing member <NUM> at the flat surface of the flange <NUM>, so it is possible to more stably support the reinforcing member <NUM>.

Further, according to the configuration shown in <FIG>, by providing the flange <NUM> at the end part of the support member <NUM> on the reinforcing member <NUM> side, the region supporting the reinforcing member <NUM> becomes broader. Therefore, if an impact load is applied from outside of the exterior panel <NUM>, even if the position of the crossing part C shifts in the vertical direction or horizontal direction along the surface of the outer panel <NUM> when receiving the impact load, the position of the crossing part C will not leave the region of the flange <NUM> and the impact load can be reliably transferred from the crossing part C to the support member <NUM>.

<FIG> is a schematic cross-sectional view showing a support member <NUM> with an end part at the reinforcing member <NUM> side extending toward the axial center and formed with a surface <NUM> facing a reinforcing member <NUM> at the reinforcing member <NUM> side. Further, <FIG> is a perspective view showing the support member <NUM> shown in <FIG>. In the support member <NUM> shown in <FIG> as well, due to the formation of the surface <NUM>, when an impact load is applied to the exterior panel <NUM>, it is possible to receive the reinforcing member <NUM> at the surface <NUM>, so it is possible to more stably support the reinforcing member <NUM>.

<FIG> is a perspective view showing an example of configuring the support member <NUM> from a polygonal tube. Further, <FIG> is a perspective view showing an example of configuring the support member <NUM> from a hexagonal tube. In this way, the shape of the support member <NUM> is not limited to a cylinder. Various tubular shapes can be employed. In particular, if configuring the support member <NUM> from a hexagonal tube, it is possible to obtain a higher impact absorption ability with respect to compression in the axial center direction. The tube-shaped members of the support members <NUM> shown in <FIG> can, for example, be produced by roll forming, press braking, or other technique.

Next, a configuration providing a support member with a position restricting part restricting the position of the reinforcing member will be explained with reference to an example of a case of a support member with a cylindrical shape. As shown in <FIG>, an end part of the support member <NUM> at the reinforcing member <NUM> side is provided with recessed parts 140b corresponding to the shapes of the reinforcing members <NUM>. The recessed parts 140b are formed to depths corresponding to the lengths of the reinforcing members <NUM> in the vehicle inner-outer direction. In the present embodiment, the depths of the recessed parts 140b are made depths about <NUM>% shorter than the lengths of the reinforcing members <NUM> in the vehicle inner-outer direction. The surface of the reinforcing member <NUM> positioned at the outermost side in the vehicle inner-outer direction is positioned at the outer side in the vehicle inner-outer direction from the top end of the support member <NUM>. The surface of the reinforcing member <NUM> positioned at the innermost side in the vehicle inner-outer direction abuts against the bottom part of the recessed part 140b. Note that a gap may be provided between the surface of the reinforcing member <NUM> positioned at the innermost side in the vehicle inner-outer and the bottom part of the recessed part 140b. <FIG> are perspective views showing support members <NUM> at which recessed parts 140b corresponding to the shapes of the reinforcing members <NUM> are provided.

<FIG> shows a support member <NUM> arranged at a crossing part C of a first reinforcing member <NUM> and a second reinforcing member <NUM>. As shown in <FIG>, at the end part of the support member <NUM> at the reinforcing member <NUM> side, four recessed parts 140b corresponding to the first reinforcing member <NUM> and the second reinforcing member <NUM> to be arranged at the crossing part C are provided.

Further, <FIG> shows a support member <NUM> arranged between two adjoining crossing parts C. The support member shown in <FIG> corresponds to a support member <NUM> arranged at a position shown in <FIG>. As shown in <FIG>, at the end part of the support member <NUM> at the reinforcing member <NUM> side, two recessed parts 140b corresponding to a first reinforcing member <NUM> are provided.

<FIG> is a perspective view showing the state where the support member <NUM> shown in <FIG> is arranged at a crossing point C where a first reinforcing member <NUM> and a second reinforcing member <NUM> cross. As shown in <FIG>, the first reinforcing member <NUM> and the second reinforcing member <NUM> enter into the recessed parts 140b of the support member <NUM>. Therefore, if an impact load is applied to the exterior panel <NUM>, the support member <NUM> and the first reinforcing member <NUM> and second reinforcing member <NUM> are kept from becoming offset in position relative to each other and the impact load is reliably transferred from the crossing part C to the support member <NUM>.

Further, <FIG> is a perspective view showing the state where the support member <NUM> shown in <FIG> is arranged at a position shown in <FIG>. As shown in <FIG>, the first reinforcing member <NUM> enters into the recessed parts 140b of the support member <NUM>. Therefore, if an impact load is applied to the exterior panel <NUM>, the support member <NUM> and the first reinforcing member <NUM> are kept from becoming offset in position relative to each other and the impact load is reliably transferred from the crossing part C to the support member <NUM>.

Next, based on <FIG>, the configurations of support members <NUM> provided with partition members will be explained. The examples of configuration shown in <FIG> are ones of provision of partition members <NUM> inside the support members <NUM> arranged in the axial center directions and using the partition members <NUM> to partition the tube-shaped members of the support members <NUM> into pluralities of sections.

By providing partition members <NUM> arranged in the axial center direction, when an impact load is applied to the exterior panel <NUM> from the outside and the impact load is applied to the support member <NUM> through the outer panel <NUM> and the reinforcing member <NUM>, the partition members <NUM> are crushed. Therefore, by providing the partition members <NUM>, the support member <NUM> becomes more resistant to being crushed in the axial center direction, so the impact absorption ability of the support member <NUM> is improved more. Further, by providing a plurality of thin partition members <NUM>, it is possible to lighten the weight while raising the impact absorption ability of the support member <NUM>, so it is possible to secure the necessary strength and, further, keep down the weight of the support member <NUM>.

<FIG> is a perspective view showing a support member <NUM> provided with partition members <NUM>. Further, <FIG> is a plan view of the support member <NUM> shown in <FIG> seen from the direction of the axial center. In the example of <FIG>, eight partition members <NUM> are provided at intervals of <NUM>° angle about the axial center of the cylinder of the support member <NUM>.

Further, <FIG> are schematic views showing other examples of support members <NUM> provided with partition members <NUM> and plan views of the support members <NUM> seen from the axial center direction. <FIG> shows an example of provision of four partition members <NUM> at intervals of <NUM>° angle about the axial center of the cylinder of the support member <NUM>, while <FIG> shows an example of provision of three partition members <NUM> at intervals of <NUM>° angle about the axial center.

In all of the examples of <FIG> as well, it is possible to raise the impact absorption ability of the support members <NUM>, but the greater the number of the partition members <NUM>, the higher the rigidity becomes in the direction in which the impact load is applied, so the impact absorption ability becomes higher.

Further, <FIG> is a schematic view showing another example of a support member <NUM> provided with partition members <NUM> and a plan view of the support member <NUM> seen from the axial center direction. <FIG> shows an example of placement of partition members <NUM> in a honeycomb structure. According to the example shown in <FIG>, it is possible to place a greater number of partition members <NUM>, so it is possible to further raise the impact absorption ability.

In the above-mentioned examples, in each case, the support member <NUM> was explained as a structure having a tubular shaped part, but the support member <NUM> may also be a structure other than a tubular shape.

<FIG> is a schematic view showing an example of configuring the support member <NUM> from a hat-shaped member. As shown in <FIG>, the support member <NUM> need not be made a tube-shaped member and can be configured as a hat shape. In a hat-shaped support member <NUM> as well, the flanges <NUM> are fixed to the inner panel <NUM> by welding etc. Further, in the case of a hat-shaped support member <NUM>, if an impact load is applied to the exterior panel <NUM> from the outside, the impact load is absorbed by side walls <NUM> being crushed.

<FIG> and <FIG> are schematic views for explaining the results of comparison and evaluation of impact absorption abilities at the time of impact (side impact) from the vehicle side surface for tube-shaped member support members <NUM> and hat-shaped support members <NUM>.

In this evaluation, as shown in <FIG>, a diameter <NUM> pole-shaped indenter <NUM> was made to strike a door panel as an exterior panel <NUM> perpendicularly by a constant speed of <NUM>/h. The absorption energy until an amount of displacement of the indenter <NUM> of <NUM> was measured. This evaluation envisions a case of telephone pole or other structure striking a door panel of a vehicle from a side surface. The shape of the indenter <NUM> is made a pole shape envisioning a telephone pole. Further, EA values were found for the cases making the support members <NUM> tube-shaped members and the cases making the support members <NUM> hat shapes. An "EA value" is the value of the absorption energy when providing a support member <NUM> divided by the absorption energy of a comparative example when not providing a support member <NUM>. The EA values were found for the cases making the support members <NUM> tube-shaped members and the cases making the support members <NUM> hat shapes and the performance ratios of tube-shaped members with respect to hat shapes were calculated.

At that time, the support members <NUM> were placed at the positions of <NUM> to <NUM> shown in <FIG>. Cases of placing the support members <NUM> at one or more positions were evaluated. The following Table <NUM> shows the nos. of the placement positions of the support member <NUM> and results of the performance ratios of pipes with respect to hats.

For example, under the conditions of No. <NUM> of Table <NUM>, support members <NUM> were placed at the four locations of <NUM>, <NUM>, <NUM>, and <NUM> shown in <FIG> and the indenter <NUM> was made to strike the exterior panel <NUM>. In this case, the performance ratio of the tube-shaped members (pipe) with respect to the hat shape was <NUM>. Therefore, when placing the support members <NUM> at the four locations of <NUM>, <NUM>, <NUM>, and <NUM> of <FIG>, the result was a higher impact absorption ability with a tube-shaped member than a hat shape.

As shown in Table <NUM>, in all of the conditions of <NUM> to <NUM>, better results were obtained in the EA values of the tube-shaped members than hat shapes. From this, it will be understood that in the case of a tube-shaped member support member <NUM>, the support member <NUM> is crushed and impact is effectively absorbed in the direction in which the impact load is applied. Further, in the case of a tube-shaped member support member <NUM>, there is greater resistance to deformation in a specific direction compared with a hat-shaped support member <NUM>, so impact can be reliably absorbed. Therefore, an impact load can be absorbed even by a hat-shaped support member <NUM>, but making the member a tube shape rather than a hat shape enables the impact absorption ability of the support member <NUM> to be raised more. Further, by arranging the above-mentioned partition members <NUM> inside of the pipe, the impact absorption ability can be further raised by the partition members <NUM> being crushed when an impact load is applied.

Claim 1:
A reinforcing structure of an automobile exterior panel comprising
an outer panel (<NUM>) of a sheet shape,
reinforcing members (<NUM>) including a plurality of first members (<NUM>) of long shapes arranged at a vehicle inner side from said outer panel (<NUM>) and a plurality of second members (<NUM>) of long shapes arranged at a vehicle inner side from said outer panel (<NUM>) and crossing said plurality of first members (<NUM>),
an inner panel (<NUM>) of a sheet shape arranged at a vehicle inner side from said first members (<NUM>) and said second members (<NUM>), and
characterized by
support members (<NUM>) provided at said inner panel (<NUM>) at a vehicle outer side thereof and supporting said first members (<NUM>) or said second members (<NUM>) from a vehicle inner side,
said support members (<NUM>) supporting said first members (<NUM>) or said second members (<NUM>) at a plurality of crossing parts where said first members (<NUM>) and said second members (<NUM>) cross or between such adjoining crossing parts,
wherein the end part of said support member (<NUM>) at said reinforcing member (<NUM>) side is close to or in contact with the surface of said reinforcing member (<NUM>) at the vehicle inner side.