Pedestrian protection apparatus for vehicle

A pedestrian protection apparatus for a vehicle, including a plate member which is disposed at a front face of the vehicle, which includes front and rear portions, and which is fixed at the rear portion to the vehicle with at least a leading end part of the front portion protruded from the front face of the vehicle, the apparatus being arranged to sweep a leg portion of a pedestrian, thereby protecting the leg portion, wherein the leading end part includes at least one horizontally extending portion and a plurality of vertically extending portions each having an anterior surface substantially orthogonal to a horizontal plane, the horizontally extending portion and the vertically extending portions being formed integrally with the leading end part so as to be alternately disposed in the frontward and backward direction of the vehicle and extend in a staircase-like form.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates in general to a pedestrian protection apparatus for a vehicle, and in particular to an improved structure of the pedestrian protection apparatus disposed at a lower part of a front face of the vehicle and arranged to sweep a leg portion of a pedestrian by contact with the leg portion of the pedestrian that has collided with or contacted the front face of the vehicle, thereby protecting the leg portion of the pedestrian.

2. Discussion of Related Art

In vehicles such as automotive vehicles, there are conventionally disposed, at a front face, a rear face, or a side face, of the vehicles, various types of protection apparatus which absorb an impact energy generated upon a collision for thereby protecting a vehicle body and passengers of the vehicle. In recent years, there is disposed, at the front face of the vehicle, an apparatus for protecting a pedestrian upon collision or contact of the pedestrian with the front face of the vehicle.

As one type of the pedestrian protection apparatus, there is known a so-called leg-sweep apparatus which is disposed inside of a front bumper or disposed independently of the front bumper. The leg-sweep apparatus is arranged to apply, to a leg portion of the pedestrian, counterforce with respect to an impact load that is inputted upon collision of the pedestrian with the front face of the vehicle and sweep (scoop up) the leg portion of the pedestrian, thereby causing the pedestrian to fall down or to be thrown over toward the vehicle. Thus, it is possible to minimize occurrence of injuries to the knee such as bone fractures, thereby assuring protection and safety of the pedestrian.

Examples of the leg-sweep apparatus as one type of the pedestrian protection apparatus are disclosed in a patent publication document 1 (JP-A-2001-277963) and a patent publication document 2 (JP-A-2004-25976), for instance. The pedestrian protection apparatus disclosed in the patent publication document 1 is arranged to be disposed at the lower part of the front face of the vehicle and includes resin foam body which extends in a vehicle width direction with at least a part of the resin foam body protruded from the front face of the vehicle and a beam member which extends in the vehicle width direction while being in contact with the back surface of the resin foam body. The pedestrian protection apparatus disclosed in the patent publication document 2 is arranged to be disposed at the lower part of the vehicle and includes a metal pipe or the like which is fixed to the lower part of the front face of the vehicle so as to extend in the vehicle width direction. However, the pedestrian protection apparatus disclosed in those documents have drawbacks which should be rectified. In the former pedestrian protection apparatus including the resin foam body and the beam member, the number of the components is undesirably large, and therefore the cost of the components is high. Further, it is troublesome to install or mount the apparatus on the vehicle. In the latter pedestrian protection apparatus including the metal pipe, the weight of the apparatus inevitably increases. In addition, it is difficult to form into a configuration following that of the front face of the vehicle.

Under such situations, there has been proposed, in a patent publication document 3 (JP-A-2004-203183), for instance, a pedestrian protection apparatus arranged to be disposed to extend in a frontward and backward direction of a vehicle. The disclosed apparatus includes a plate member which is formed of a synthetic resin, which includes a front portion and a rear portion, and which is fixed at the rear portion to the vehicle with at least a leading end part of the front portion protruded from the front face of the vehicle. The pedestrian protection apparatus disclosed in the patent publication document 3 is arranged to sweep a leg portion of a pedestrian that has collided with the front face of the vehicle by contact of the leading end part of the front portion of the plate member protruding from the front face of the vehicle, with the leg portion of the pedestrian. In this conventional pedestrian protection apparatus, there are formed, on one surface of the front portion of the plate member, a plurality of first ribs having a planar shape and extending in the frontward and backward direction of the vehicle and a plurality of second ribs having a planar shape and extending in the width direction of the vehicle, which first and second ribs are assembled in a lattice. In this structure, the front portion of the plate member is reinforced, that is, the rigidity of the front portion of the plate member is increased, owing to the ribs formed thereon.

In such a pedestrian protection apparatus, the number of the components is small. Further, the plate member whose leading end part is protruded from the front face of the vehicle is made of the synthetic resin that is excellent in formability. Accordingly, the disclosed apparatus assures protection of the pedestrian while eliminating the drawbacks of the above-indicated apparatus including the resin foam body and the beam member and the drawbacks of the above-indicated apparatus including the metal pipe. Further, the front portion of the plate member is reinforced, that is, the rigidity of the front portion is increased, by the plurality of first and second ribs formed as described above, whereby, when the front portion of the plate member comes into contact with the leg portion of the pedestrian, the front portion is prevented from being deformed due to impact upon the contact or the deformation amount of the front portion is made sufficiently small. Therefore, it is possible to stably assure counterforce with respect to the impact load inputted to the plate member.

However, the conventional pedestrian protection apparatus having the plate member formed of the synthetic resin experiences the following drawbacks.

The above-described pedestrian protection apparatus is generally disposed inside of the front bumper such that the planar second ribs provided on the front portion of the plate member are opposed to the inner surface of the front bumper. The cross sectional shape of the front bumper taken along a vertical plane which is parallel to the frontward and backward direction of the vehicle is a convex curved shape protruding forward. Where the inner surface of the front bumper has a convex curved surface configuration in correspondence with the shape of the front bumper, there is inevitably formed a comparatively large clearance between the inner surface of the front bumper and the planar second ribs of the plate member.

Further, in the pedestrian protection apparatus described above, in general, the leading end part of the front portion of the plate member is positioned so as to protrude from the front face of the vehicle with the rear portion of the plate member fixed to a radiator support, a cross member or the like. Accordingly, the dimension of the plate member as measured in the frontward and backward direction of the vehicle is relatively large. The increase in the dimension of the plate member as measured in the frontward and backward direction of the vehicle, however, leads to insufficient rigidity (insufficient strength with respect to deformation) against the impact load inputted thereto upon collision of the leg portion of the pedestrian with the front face of the vehicle. Where the flexural or bending rigidity of the plate member is insufficient, the front portion of the plate member is initially deflected or bent with ease, so that the timing of initial rise of the impact load in the load characteristics (abrupt rise of the load in the load-displacement curve) is delayed, thereby making it impossible to instantaneously exhibit sufficient counterforce with respect to the impact load. In this case, the pedestrian protection apparatus fails to instantaneously or promptly sweep the leg portion of the pedestrian.

In the meantime, as the pedestrian protection apparatus which is to be disposed inside of the front bumper with the leading end part of the front portion of the plate member opposed to the inner surface of the front bumper having the convex curved surface configuration, there is known a structure that the surface of the leading end part of the plate member that confronts the inner surface of the front bumper is made as a convex curved surface corresponding to the inner surface of the front bumper, as disclosed in a patent publication document 4 (JP-A-2002-274298), for instance. The disclosed structure prevents formation of a large clearance between the leading end part of the plate member and the inner surface of the front bumper.

In the pedestrian protection apparatus having such a structure, however, the impact load that acts in a backward direction of the vehicle when the leg portion of the pedestrian collides with the front bumper is inputted to the convex curved surface of the leading end part of the plate member. Accordingly, upon the input of the impact load, there is a generated force that lifts up the leading end part of the plate portion. In this instance, the leading end part of the plate member is deformed so as to be rolled up, resulting in a delay in the rise of the impact load in the load characteristics. Accordingly, the pedestrian protection apparatus in which the leading end part of the plate member has a shape that corresponds to the shape of the inner surface of the front bumper also suffers from the problem that the leg portion of the pedestrian cannot be promptly swept.

SUMMARY OF THE INVENTION

The present invention has been developed in the light of the aforementioned situations. It is therefore an object of the invention to provide a pedestrian protection apparatus for a vehicle capable of sufficiently protecting a leg portion of a pedestrian that has collided with a front face of the vehicle by promptly and reliably sweeping the leg portion of the pedestrian.

The above-indicated object of the invention may be attained according to a first aspect of the invention, which provides a pedestrian protection apparatus for a vehicle, comprising a plate member which is disposed at a lower part of a front face of the vehicle so as to extend in a frontward and backward direction of the vehicle, which is made of a synthetic resin, which includes a front portion and a rear portion, and which is fixed at the rear portion to the vehicle with at least a leading end part of the front portion protruded from the front face of the vehicle, the apparatus being arranged to sweep a leg portion of a pedestrian that has collided with the front face of the vehicle by contact of the leading end part of the front portion of the plate member with the leg portion of the pedestrian, thereby protecting the leg portion of the pedestrian, wherein the leading end part of the front portion of the plate member includes at least one horizontally extending portion each of which extends horizontally in the frontward and backward direction of the vehicle and a plurality of vertically extending portions each of which has an anterior surface substantially orthogonal to a horizontal plane and each of which extends in a vertical direction, the at least one horizontally extending portion and the plurality of vertically extending portions being formed integrally with the leading end part such that each of the at least one horizontally extending portion and each of the plurality of vertically extending portions are alternately disposed in the frontward and backward direction of the vehicle so as to extend in a staircase-like form, whereby the leading end part has a staircase-like portion constituted by the at least one horizontally extending portion and the plurality of vertically extending portions.

The “horizontally extending” state mentioned in the present specification is not strictly limited to a state of extending straightly in a horizontal direction, but includes a state of extending while inclining with respect to the horizontal direction by a slight angle. Similarly, the “vertically extending” state is not strictly limited to a state of extending straightly in a vertical direction, but includes a state of extending while inclining with respect to the vertical direction by a slight angle. Further, “an anterior surface substantially orthogonal to a horizontal plane” includes both of a flat surface or a curved surface formed by a moving path of a vertical line and a flat surface or a curved surface formed by a moving path of a straight line that is inclined with respect to the vertical direction by a slight angle. Hereinafter, these terms are used in the respective meanings described above.

In the pedestrian protection apparatus constructed according to the above-indicated first aspect of the invention, the impact load generated accompanied by the collision of the leg portion of the pedestrian is inputted, at the leading end part of the plate member, substantially perpendicularly to the anterior surface of each of the plurality of vertically extending portions in the staircase-like portion. Accordingly, unlike the conventional apparatus in which the front face of the leading end part of the plate member is made as a convex curved surface corresponding to the inner surface of the front bumper whose vertical cross sectional shape is the above-described convex curved shape, the present apparatus does not suffer from force that lifts up the leading end part of the plate member upon inputting of the impact load thereto, so that it is possible to advantageously eliminate or restrain the delay of the rise of the impact load in the load characteristics due to occurrence of deformation of the leading end part of the plate member so as to be rolled up. In addition, upon the collision with the leg portion of the pedestrian, the area of the leading end part of the plate member which comes into contact with the leg portion of the pedestrian can be made large. Consequently, the impact load can be reliably and sufficiently inputted to the leading end part of the plate member, allowing larger counterforce to be exhibited.

In the present apparatus, a part of or an entirety of the leading end part of the plate member is formed by the staircase-like portion constituted by the plurality of vertically extending portions and the at least one horizontally extending portion. According to the arrangement, at the leading end part of the plate member, the plurality of vertically extending portions are located at mutually different height levels in the forward and backward direction with each of the at least one horizontally extending portion being interposed between adjacent two of the plurality of vertically extending portions. Therefore, even where the leading end part of the plate member is deposed inside of the front bumper whose vertical cross sectional shape is the curved convex shape, such that the leading end part of the plate member is opposed to the inner surface of the front bumper having the curved convex shape, the clearance formed between the inner surface of the front bumper and the anterior surface of each vertically extending portion can be minimized.

Because the staircase-like portion includes the at least one horizontally extending portion, there are formed portions extending in a direction in which the impact load is inputted (i.e., horizontal portions extending in the horizontal direction that is the frontward and backward direction of the vehicle) at a plural locations of the plate member such that those portions have mutually different height levels. Accordingly, the counterforce with respect to the impact load can be sufficiently exhibited at the plurality of locations. Moreover, the portions of the plate portion that extend in the input direction of the impact load are in a divided state, so that moment arm in the plate member can be advantageously shortened, thereby reducing rotation force generated in the plate member upon inputting of the impact thereto. Therefore, it is possible to prevent, with high reliability, the leading end part of the plate member from being deformed or rolled up, resulting in a prompt rise of the impact load in the load characteristics.

In the pedestrian protection apparatus constructed as described above, it is possible to promptly and reliably sweep, with sufficient counterforce, the leg portion of the pedestrian that has collided with the front face of the vehicle even when the apparatus is disposed independently of the front bumper and even when the apparatus is disposed inside of the front bumper whose vertical cross sectional shape is the convex curved shape. As a result, the present apparatus is capable of sufficiently protecting the leg portion of the pedestrian at a higher level.

Because the present pedestrian protection apparatus permits a prompt rise of the impact load in the load characteristics, the impact load reaches a target value quickly. Accordingly, the present pedestrian protection apparatus effectively assures a sufficient amount of the impact-absorbing stroke accompanied by buckling deformation of the horizontally extending portion after the impact load in the load characteristics has reached the target value.

The above-indicated object of the present invention may also be attained according to a second aspect of the invention, which provides a pedestrian protection apparatus for a vehicle, comprising a plate member which is disposed at a lower part of a front face of the vehicle so as to extend in a frontward and backward direction of the vehicle with a suitable width, which is made of a synthetic resin, which includes a front portion and a rear portion, and which is fixed at the rear portion to the vehicle with at least a leading end part of the front portion protruded from the front face of the vehicle, the apparatus being arranged to sweep a leg portion of a pedestrian that has collided with the front face of the vehicle by contact of the leading end part of the front portion of the plate member with the leg portion of the pedestrian, thereby protecting the leg portion of the pedestrian, wherein the plate member includes: a horizontally extending portion which is located at the leading end part of the front portion of the plate member so as to horizontally extend over an entire width of the plate member; a front-side vertically extending portion which is formed integrally with a front end of the horizontally extending portion so as to extend in a vertical direction; a rear-side vertically extending portion which is formed integrally with a rear end of the horizontally extending portion so as to extend in the vertical direction such that the rear-side vertically extending portion is opposed to the front-side vertically extending portion with a suitable distance interposed therebetween; and a connecting portion which is constituted by a proximal end part of the front portion of the plate member that extends in the frontward and backward direction on the back side of the rear-side vertically extending portion and which connects, integrally to the rear portion of the plate member, a posterior surface of the rear-side vertically extending portion at a point thereof having a height position different from a height position of a connecting point of an anterior surface of the rear-side vertically extending portion at which the rear-side vertically extending portion is connected to the horizontally extending portion, and wherein the front portion of the plate member is constituted by including, at the leading end part thereof, a U-shaped portion having a U-shaped configuration in vertical cross section.

Concerning the “horizontally extending” state and the “vertically extending” state, the explanation made above with respect to the first aspect is applicable.

In the pedestrian protection apparatus constructed according to the above-indicated second aspect of the invention, the U-shaped portion provided at the leading end part of the front portion of the plate member functions as a bead that reinforces the front portion of the plate member. Accordingly, even when the entire length of the plate member (i.e., the dimension of the plate member as measured in the frontward and backward direction of the vehicle) is relatively large, it is possible to sufficiently assure bending or flexural strength of the front portion, in particular, the rigidity (the strength with respect to deformation) against the impact load inputted thereto upon the collision of the leg portion of the pedestrian with the front face of the vehicle. Therefore, the front portion of the plate member is advantageously prevented from easily deflected upon inputting of the impact load.

In the pedestrian protection apparatus constructed according to the above-indicated second aspect of the invention, when the leg portion of the pedestrian comes into contact with the leading end part of the front portion of the plate member as a result of collision of the leg portion against the front face of the vehicle, the front-side vertically extending portion is deformed so as to be inclined with respect to the vertical direction by a suitable angle while the horizontally extending portion is displaced backward. Further, the rear-side vertically extending portion is deformed so as to be inclined with respect to the vertical direction by a suitable angle. Accordingly, the impact load is designed to be gradually transmitted from the front portion to the rear portion of the plate member. In this instance, since the front-side and the rear-side vertically extending portions are formed to extend in the vertical direction over the entire width of the plate member, those front-side and rear-side vertically extending portions are deformed over a wide range in the width direction of the plate member (i.e., in the vehicle width direction), whereby the impact load can be effectively transmitted also in the width direction of the plate member. As a result, the impact load is advantageously distributed in the front portion of the plate member, so that the leading end part of the plate member is effectively prevented from being easily deflected.

Moreover, in the present apparatus, the impact load generated by the collision of the leg portion of the pedestrian is inputted substantially perpendicularly with respect to the front-side vertically extending portion located at the leading end part of the plate member. According to the arrangement, there is generated no force that lifts up the leading end part of the plate member upon inputting of the impact load thereto, thereby effectively preventing the leading end part of the plate member from being deformed, i.e., rolled up.

Thus, in the pedestrian protection apparatus constructed according to the second aspect of the invention, the front portion of the plate member is effectively prevented from being easily deformed or deflected by the impact load, arising from insufficient rigidity with respect to the impact load, concentration of stress of the impact load, the configuration of the leading end part of the plate portion, and the like. As a result, the delay of the rise of the impact load in the load characteristics can be obviated.

The pedestrian protection apparatus constructed as described above permits a prompt rise of the impact load in the load characteristics and thereby instantaneously exhibits a sufficient degree of counterforce with respect to the impact load. Consequently, the present pedestrian protection apparatus is capable of promptly and reliably sweeping the leg portion of the pedestrian which collided with the front face of the vehicle, thereby protecting the leg portion with higher reliability.

Because the present pedestrian protection apparatus permits a prompt rise of the impact load in the load characteristics as described above, the impact load reaches a target value more quickly. Accordingly, the present pedestrian protection apparatus effectively assures a sufficient amount of the impact-absorbing stroke is accompanied by buckling deformation of the horizontally extending portion after the impact load in the load characteristics has reached the target value.

The present invention is preferably practiced in at least the following forms.

(1) A pedestrian protection apparatus for a vehicle, comprising a plate member which is disposed at a lower part of a front face of the vehicle so as to extend in a frontward and backward direction of the vehicle, which is made of a synthetic resin, which includes a front portion and a rear portion, and which is fixed at the rear portion to the vehicle with at least a leading end part of the front portion protruded from the front face of the vehicle, the apparatus being arranged to sweep a leg portion of a pedestrian that has collided with the front face of the vehicle by contact of the leading end part of the front portion of the plate member with the leg portion of the pedestrian, thereby protecting the leg portion of the pedestrian, where the leading end part of the front portion of the plate member includes at least one horizontally extending portion each of which extends horizontally in the frontward and backward direction of the vehicle and a plurality of vertically extending portions each of which has an anterior surface substantially orthogonal to a horizontal plane and each of which extends in a vertical direction, the at least one horizontally extending portion and the plurality of vertically extending portions being formed integrally with the leading end part such that each of the at least one horizontally extending portion and each of the plurality of vertically extending portions are alternately disposed in the frontward and backward direction of the vehicle so as to extend in a staircase-like form, whereby the leading end part has a staircase-like portion constituted by the at least one horizontally extending portion and the plurality of vertically extending portions.

(2) The apparatus according to the above form (1), where a forward end of the staircase-like portion is constituted by one of the plurality of vertically extending portions, and one of vertically opposite ends of the one of the plurality of vertically extending portions that is nearer to one of the at least one horizontally extending portion which is adjacent to the one of the plurality of vertically extending portions is located at a middle portion of the staircase-like portion (including the vicinity of the middle portion) in a height direction thereof.

According to the above-indicated form (2), upon collision of the leg portion of the pedestrian against the front face of the vehicle, the leg portion is initially brought into contact with the front end of the horizontally extending portion located at the middle portion of the staircase-like portion in its height direction. Accordingly, the impact load acts, with high reliability, on the leading end part of the plate member in the horizontal direction, whereby the leading end part of the plate member is more effectively prevented from being deformed or rolled up. As a result, the leg portion of the pedestrian can be more efficiently and reliably protected.

(3) The apparatus according to the above form (1), wherein a forward end of the staircase-like portion is constituted by one of the at least one horizontally extending portion.

According to the above-indicated form (3), when the present pedestrian protection apparatus is disposed inside of the front bumper having the convex curved configuration in the vertical cross section, a clearance between the inner surface of the front bumper and the leading end part of the plate member can be made small, thereby effectively assuring a prompt rise of the impact load in the load characteristics. Hence, the protection of the leg portion of the pedestrian can be realized at a higher level.

(4) The apparatus according to any one of the above forms (1)-(3), wherein reinforcing ribs for reinforcing the front portion of the plate member are formed on a part of the front portion that at least includes the staircase-like portion, such that the reinforcing ribs are integral with posterior surfaces of the plurality of vertically extending portions in the staircase-like portion, so as to extend in the frontward and backward direction of the vehicle.

According to the above-indicated form (4), the rigidity of the front portion of the plate member can be advantageously increased, thereby permitting the counterforce with respect to the impact load to be sufficiently exhibited. In consequence, the function of protecting the leg portion of the pedestrian can be effectively enhanced. Further, by adjusting the number, the location, etc., of the reinforcing ribs which are provided on the part of the front portion of the plate member that at least includes the staircase-like portion, the rigidity of the front portion of the plate member can be suitably changed, whereby the amount of buckling deformation of the front portion of the plate member accompanied by the input of the impact load can be easily tuned depending upon the magnitude of the impact load to be inputted.

(5) A pedestrian protection apparatus for a vehicle, comprising a plate member which is disposed at a lower part of a front face of the vehicle so as to extend in a frontward and backward direction of the vehicle with a suitable width, which is made of a synthetic resin, which includes a front portion and a rear portion, and which is fixed at the rear portion to the vehicle with at least a leading end part of the front portion protruded from the front face of the vehicle, the apparatus being arranged to sweep a leg portion of a pedestrian that has collided with the front face of the vehicle by contact of the leading end part of the front portion of the plate member with the leg portion of the pedestrian, thereby protecting the leg portion of the pedestrian, where the plate member includes: a horizontally extending portion which is located at the leading end part of the front portion of the plate member so as to horizontally extend over an entire width of the plate member; a front-side vertically extending portion which is formed integrally with a front end of the horizontally extending portion so as to extend in a vertical direction; a rear-side vertically extending portion which is formed integrally with a rear end of the horizontally extending portion so as to extend in the vertical direction such that the rear-side vertically extending portion is opposed to the front-side vertically extending portion with a suitable distance interposed therebetween; and a connecting portion which is constituted by a proximal end part of the front portion of the plate member that extends in the frontward and backward direction on the back side of the rear-side vertically extending portion and which connects, integrally to the rear portion of the plate member, a posterior surface of the rear-side vertically extending portion at a point thereof having a height position different from a height position of a connecting point of an anterior surface of the rear-side vertically extending portion at which the rear-side vertically extending portion is connected to the horizontally extending portion, and where the front portion of the plate member is constituted by including, at the leading end part thereof, a U-shaped portion having a U-shaped configuration in vertical cross section.

(6) A pedestrian protection apparatus for a vehicle, comprising a plate member which is disposed at a lower part of a front face of the vehicle so as to extend in a frontward and backward direction of the vehicle with a suitable width, which is made of a synthetic resin, which includes a front portion and a rear portion, and which is fixed at the rear portion to the vehicle with at least a leading end part of the front portion protruded from the front face of the vehicle, the apparatus being arranged to sweep a leg portion of a pedestrian that has collided with the front face of the vehicle by contact of the leading end part of the front portion of the plate member with the leg portion of the pedestrian, thereby protecting the leg portion of the pedestrian, where the plate member includes: a front-side vertically extending portion which is located at the leading end part of the front portion of the plate member so as to vertically extend over an entire width of the plate member; a plurality of rear-side vertically extending portions which are located at the back of the front-side vertically extending portion with a suitable distance interposed therebetween so as to extend in the vertical direction over the entire width of the plate member such that the plurality of rear-side vertically extending portions are opposed to the front-side vertically extending portion and spaced apart from each other by a suitable distance in the frontward and backward direction; a plurality of horizontally extending portions which are located between mutually corresponding vertical ends of a forwardmost one of the plurality of rear-side vertically extending portions and the front-side vertically extending portion and between mutually corresponding vertical ends of the plurality of rear-side vertically extending portions, such that the plurality of horizontally extending portions horizontally extend over the entire width of the plate member and such that two adjacent of the plurality of horizontally extending portions in the frontward and backward direction are located at mutually different height levels, thereby connecting the front-side vertically extending portion and the forwardmost one of the plurality of rear-side vertically extending portions integrally to each other and connecting the plurality of rear-side vertically extending portions to each other; and a connecting portion which is constituted by a proximal end part of the front portion of the plate member that is located on the back side of a rearmost one of the plurality of rear-side vertically extending portions so as to extend in the frontward and backward direction and which connects, integrally to the rear portion of the plate member, a posterior surface of the rearmost one of the plurality of rear-side vertically extending portions at a point thereof having a different height position from that of a connecting point of an anterior surface of the rearmost one of the plurality of vertically extending portions at which the rearmost one of the plurality of vertically extending portions is connected to a corresponding one of the plurality of horizontally extending portions, and where the leading end part of the front portion of the plate member extends in a zigzag form in a height direction with a U-shaped configuration in vertical cross section.

According to the above-indicated form (6), the leading end part of the front portion of the plate member has a U-shaped configuration in vertical cross section and is made as a zigzag portion in which the U-shaped portion functioning bead is continuously formed in the frontward and backward direction. Accordingly, the rigidity with respect to the impact load can be advantageously increased at the front portion of the plate member. Further, the present apparatus includes, in addition to the front-side vertically extending portion to which the impact load is inputted substantially perpendicularly, the plurality of horizontally extending portions which are displaced backward upon inputting of the impact load and the plurality of rear-side vertically extending portions which are deformed so as to be inclined with respect to the vertical direction by a prescribed angle. Accordingly, the impact load can be more sufficiently transmitted toward the width direction of the plate member and effectively distributed.

The above-indicated form (6), therefore, permits a prompt rise of the impact load in the load characteristics, so that sufficient counterforce with respect to the impact load can be exhibited at an earlier time. As a result, the leg portion of the pedestrian collided with the front face of the vehicle can be instantaneously and reliably swept, assuring further enhanced performance of protecting the leg portion of the pedestrian.

Because the above-indicated form (6) permits a prompt rise of the impact load in the load characteristics, the impact load can reach a target value quickly, thereby effectively assuring a sufficient amount of the impact-absorbing stroke accompanied by buckling deformation of the horizontally extending portion after the impact load in the load characteristics has reached the target value.

(7) The apparatus according to the above form (5) or (6), wherein the front-side vertically extending portion is bent at substantially right angles at a plurality of locations of a middle portion thereof as seen in a height direction thereof, so as to extend in the vertical direction in a staircase-like form.

According to the above-indicated form (7), there are formed portions that extend horizontally, at a plurality of locations of a staircase-like portion located at the leading end part of the front portion of the plate member, such that those portions are in a divided state. Accordingly, the moment arm in front portion of the plate member can be advantageously shortened, thereby reducing rotation force generated in the front portion of the plate member upon inputting of the impact thereto. Therefore, it is possible to prevent, with high reliability, the front portion of the plate member from being easily deflected, resulting in a prompt rise of the impact load in the load characteristics.

Further, according to the above-indicated form (7), the plurality of portions which extend horizontally and which are provided at the leading end part of the plate member are located at mutually different height levels in the frontward and backward direction. Therefore, where the present pedestrian protection apparatus is disposed inside of the front bumper having the convex curved configuration in vertical cross section such that the leading end part of the front portion of the plate member is opposed to the inner surface of the front bumper constituted by the convex curved surface, it is possible to minimize a clearance formed between the inner surface of the front bumper and the front face of the leading end part of the plate member. Therefore, it is possible to effectively eliminate or restrain the delay of the rise of the impact load in the load characteristics arising from the presence of the clearance between the inner surface of the front bumper and the leading end part of the plate member.

Accordingly, the above-indicated form (7) permits sufficient counterforce with respect to the impact load to be exhibited instantaneously, so that the leg portion of the pedestrian collided with the front face of the vehicle can be promptly and reliably swept, assuring advantageous enhanced performance of protection of the leg portion of the pedestrian.

(8) The apparatus according to any one of the above forms (5)-(7), wherein reinforcing portions for increasing strength of the front portion of the plate member is provided on the front portion, so to prevent easy deformation of the front portion due to an impact load applied thereto resulting from collision of the leg portion of the pedestrian with the front face of the vehicle.

According to the above-indicated form (8), it is possible to effectively eliminate or restrain easy deflection of the front portion of the plate member by the impact load arising from insufficient rigidity with respect to the impact load. As a result, the above-indicated form (8) effectively realizes a prompt rise of the impact load in the load characteristics and improvement of the function of protecting the leg portion of the pedestrian.

(9) The apparatus according to the above form (8), wherein the reinforcing portions are constituted by reinforcing ribs formed integrally on the front portion of the plate member such that the reinforcing ribs are integral with a posterior surface of the front-side vertically extending portion and posterior surfaces of the plurality of rear-side vertically extending portions, so as to extend in the frontward and backward direction.

According to the above-indicated form (9), the reinforcing portions exhibiting excellent characteristics indicated above are easily formed by molding using metallic dies, Accordingly, the reinforcing portions are advantageously realized in a comparatively simple and moderate structure without increasing the number of the components. Further, by adjusting the installation structure (i.e., the number and the location) of the reinforcing ribs provided on the front portion of the plate member, the rigidity of the front portion of the plate member can be suitably changed, thereby making it possible to easily tune the amount of the buckling deformation of the front portion of the plate member accompanied by the input of the impact load and the amount of absorption of the impact energy based on the buckling deformation of the front portion, depending upon the magnitude of the impact load to be inputted.

DETAILED DESCRIPTION OF THE INVENTION

To further clarify the present invention, there will be described in detail embodiments of the invention with reference to the accompanying drawings.

Referring first to the plan view ofFIG. 1and the vertical cross sectional view ofFIG. 2, there is schematically shown a leg-sweep apparatus as a pedestrian protection apparatus constructed according to a first embodiment of the present invention. The leg-sweep apparatus generally indicated at10inFIGS. 1 and 2is arranged to be installed inside of a front bumper which is disposed at a front face of an automotive vehicle. As apparent fromFIGS. 1 and 2, the present leg-sweep apparatus10includes a base plate12as a plate member.

The base plate12is formed of a synthetic resin material such as polypropylene or ABS resin and is constituted by a thin planar plate having a generally rectangular shape. In the base plate12, the dimension as measured in a vertical direction ofFIG. 1, i.e., the dimension as measured in a vehicle width direction or a leftward and rightward (lateral) direction of the vehicle under installation of the leg-sweep apparatus10on the vehicle, is made smaller than the vehicle width by a suitable amount, and the dimension as measured in a transverse direction ofFIG. 1, i.e., the dimension as measured in a frontward and backward direction of the vehicle (a vehicle length or running direction), is made sufficiently smaller than the above-indicated dimension as measured in the leftward and rightward direction.

The base plate12includes a front portion14which occupies a substantially front half region thereof and a rear portion16which occupies a substantially rear half region thereof. The front portion14of the base plate12has, on its upper surface, a plurality of first reinforcing rigs18(here, fourteen ribs18) each of which is a thin planar plate and which are formed integrally with the front portion14such that each first reinforcing rib18continuously and straightly extends with a constant height from a forward end of the front portion14toward a backward end thereof over the entire length of the front portion14as measured in the frontward and backward direction. The first reinforcing ribs18are opposed to and spaced apart from each other by a suitable constant distance and located parallel to each other, in the leftward and rightward direction.

At a leading end (front end) part22of the upper surface of the front portion,14, there are provided, in addition to front-side parts of the respective first reinforcing ribs18, a plurality of second reinforcing ribs20(here, fifteen ribs20) each having the same thickness and height as those of the first reinforcing ribs18and having a length shorter than that of the first reinforcing ribs18. The second reinforcing ribs20each of which is a thin planar plate are formed integrally with the leading end part22so as to continuously and straightly extend in the frontward and backward direction such that each second reinforcing rib20is interposed between adjacent two of the first reinforcing ribs18that are opposed to each other. The second reinforcing ribs20are located parallel to the first reinforcing ribs18adjacent thereto. Further, any adjacent two of the second reinforcing ribs20which sandwich a corresponding one of the first reinforcing ribs18therebetween are located parallel to each other.

The rear portion16of the plate base plate12has flat upper and lower surfaces on which no reinforcing ribs18,20are formed. At one end of the rear portion16remote from the front portion14, a plurality of insertion holes23(here, five insertion holes23) into each of which a suitable fixing bolt is insertable are formed through the thickness of the rear portion16such that the insertion holes23are spaced apart from each other by a suitable distance in the leftward and rightward direction.

In the exemplary first embodiment, the leg-sweep apparatus10is attached, at its rear portion16, to a prescribed portion of the vehicle so as to be positioned horizontally, as shown inFIG. 3. The front portion14of the base plate12on which the reinforcing ribs18,20are formed has a higher degree of rigidity with respect to bending or flexural load, i.e., a higher degree of deformation strength with respect to the impact load inputted thereto in the frontward and backward direction in a state in which the leg-sweep apparatus10is installed on the vehicle, than that of the rear portion16on which no reinforcing ribs18,20are formed. In such a front portion14, the leading end part22on which are formed both of the front-side parts of the respective first reinforcing ribs18and the second reinforcing ribs20is constructed to have a higher degree of rigidity than the rest of the front portion14other than the leading end part22.

In the present leg-sweep apparatus10, in particular, the leading end part22of the front portion14of the base plate12on which are formed the second reinforcing ribs20has a special structure not found in conventional apparatus.

Namely, the leading end part22of the front portion14of the base plate12is in a bent form obtained by bending a flat plate extending straightly in the frontward and backward direction, at right angles in the frontward and backward direction at three locations that are spaced apart from each other by a prescribed distance in the frontward and backward direction over the entire width thereof. In such a bent form, the leading end part22is formed with first, second and third bends26,28,30in order as seen from the front side, as shown inFIG. 2.

In the thus configured leading end part22of the base plate12, a portion thereof located behind the first bend26is made as a first horizontally extending portion32that extends horizontally and straightly in the frontward and backward direction under installation of the leg-sweep apparatus10on the vehicle. A portion of the leading end part22between the first bend26and the second bend28extends upright at right angles from the front end of the first horizontally extending portion32and is made as a first vertically extending portion34that extends straightly in the vertical direction under installation of the leg-sweep apparatus10on the vehicle. A portion of the leading end part22between the second bend28and the third bend30is bent at right angles from the upper end of the first vertically extending portion34and is made as a second horizontally extending portion36that horizontally and straightly extend in the frontward and backward direction under installation of the leg-sweep apparatus10on the vehicle. A portion of the leading end part22located forward of the third bend30(i.e., the forward end of the leading end part22) extends upright at right angles from the front end of the second horizontally extending portion36and is made as a second vertically extending portion38that extends straightly in the vertical direction under installation of the leg-sweep apparatus10on the vehicle.

In other words, in the leading end part22of the front portion14of the base plate12, the second vertically extending portion38and the first vertically extending portion34are respectively located on the front side and the back side of the second horizontally extending portion36with the same36interposed therebetween, such that the former38is located at a height position higher than that of the latter34. The second horizontally extending portion36and the first horizontally extending portion32are respectively located on the front side and the back side of the first vertically extending portion34with the same34interposed therebetween, such that the former36is located at a height position higher than that of the latter32. These extending portions32-38are connected integrally to each other at the three bends26-30.

Thus, in the leading end part22of the front portion14of the base plate12, each of the first and second horizontally extending portions32,36and each of the first and second vertically extending portions34,38are alternately disposed in the frontward and backward direction so as to extend in a staircase-like form, whereby the entirety of the leading end part22is made as a staircase-like portion40constituted by the first and second horizontally extending portions32,36and the first and second vertically extending portions34,38.

In the thus formed staircase-like portion40, the anterior surface of the first vertically extending portion34and the anterior surface of the second vertically extending portion38are respectively made as load-input surfaces42,43to which the impact load generated by the collision of the leg portion of the pedestrian is to be inputted. Each of the load-input surfaces42,43extends straightly in the vertical direction and has a curved surface configuration obtained by deflecting or warping a vertical plane which is right-angled with respect to a horizontal plane that includes the direction of input of the impact load generated by the collision of the leg portion of the pedestrian, such that the vertical plane is gradually curved backward from the middle portion thereof as seen in the leftward and rightward direction toward the opposite end portions thereof as seen in the same direction. Namely, each of the load-input surfaces42,43is constituted as a convex curved surface which protrudes forward and which is formed by a path that is obtained by moving a vertical line so as to draw an arc.

Because the first and second vertically extending portions34,38are disposed as mentioned above, the load-input surface43of the second vertically extending portion38is located above the load-input surface42of the first vertically extending portion34at a location away from the load-input surface42in the forward direction by a distance corresponding to the length of the second horizontally extending portion36as measured in the frontward and backward direction of the vehicle.

Here, the first and second vertically extending portions34,38have the same height (i.e., the same dimension as measured in the direction of extension thereof), whereby the first and second vertically extending portions34,38have substantially the same area. Further, the lower end of the second vertically extending portion38, i.e., the third bend30as the front end of the second horizontally extending portion36interposed between those two vertically extending portions34,38is located at the substantially middle of the staircase-like portion40in the height direction thereof.

The first reinforcing ribs18and the second reinforcing ribs20provided on the front portion14of the base plate12are formed integrally with the back surfaces of the load-input surfaces42,43of the respective first and second vertically extending portions34,38and the upper surfaces of the respective first and second horizontally extending portions32,36.

The thus constructed leg-sweep apparatus10is disposed inside of a front bumper44installed on the front face of the vehicle, as shown inFIG. 3, for example.

The front bumper44inside of which is disposed the leg-sweep apparatus10has a bumper cover50including an upper protruding portion46and a lower protruding portion48which protrude from the front face of the vehicle in a state in which the front bumper44is installed on the front face of the vehicle. Each of the upper and lower protruding portions46,48has, in vertical cross section, a convex curved surface configuration protruding forward. The bumper cover50of the front bumper44is fixed by bolts or the like to a front grille51, for instance, that constitutes the front face portion of the vehicle. InFIG. 3, the reference numerals52,54denote a bonnet and a radiator, respectively.

A known impact or shock-absorbing member56whose rigidity is smaller than that of the leg-sweep apparatus10is disposed inside of the upper protruding portion46of the bumper cover50installed on the front face of the vehicle such that the impact-absorbing member56is fixedly interposed between the upper protruding portion46and a bumper reinforcement58as a rigid member while the leg-sweep apparatus10is disposed inside of the lower protruding portion48of the bumper cover50.

More specifically described, the leg-sweep apparatus10is disposed inside of the lower protruding portion48of the bumper cover50such that the staircase-like portion40(the leading end part22) of the front portion of the base plate12is projected and inserted into an interior of the lower protruding portion48while the upper surface of the rear end of the rear portion16of the base plate12is held in contact with the lower surface of a radiator support60that is fixedly provided at a front portion of the vehicle so as to extend in the vehicle width direction, for supporting a radiator54.

In a state in which the leg-sweep apparatus10is thus disposed, the first bend26which is the lower end of the first vertically extending portion34and which is the front end of the first horizontally extending portion32is located adjacent to a lower portion of the inner surface of the lower protruding portion48while the third bend30which is the lower end of the second vertically extending portion38and which is the front end of the second horizontally extending portion36is located adjacent to a middle portion of the inner surface of the lower protruding portion48in its height direction. Further, the load-input surfaces42,43of the respective first and second vertically extending portions34,38are respectively opposed to and located as close as possible to the lower portion and the middle portion of the inner surface of the lower protruding portion48in the height direction thereof.

Fixing bolts61are respectively inserted into the plurality of insertion holes23formed at the rear end of the rear portion16of the base plate12and screwed into the radiator support60, whereby the rear portion16of the base plate12is fixed to the radiator support60.

Thus, the leg-sweep apparatus10is disposed in the lower part of the front face of the vehicle such that the leg-sweep apparatus10is horizontally located inside of the lower protruding portion48of the bumper cover50so as to extend in the frontward and backward direction of the vehicle, with the staircase-like portion40of the front portion14of the base plate12projected from the front face of the vehicle and with the rear portion16fixed to the radiator support60.

In the exemplary embodiment, when a leg portion62of the pedestrian comes into contact or collides with the bumper cover50of the front bumper44as indicated by a two-dot chain line inFIG. 3, the upper protruding portion46and the lower protruding portion48of the bumper cover50are respectively brought into contact with the vicinity of a knee64and the vicinity of a shank66of the leg portion62of the pedestrian. In this instance, since the rigidity of the impact-absorbing member56is made smaller than that of the leg-sweep apparatus10, the impact-absorbing member56is deformed more easily in a larger amount than the leg-sweep apparatus10. Accordingly, the bumper cover50is deformed such that lower protruding portion48projects frontward of the vehicle farther than the upper protruding portion46, so that the counterforce with respect to the impact load generated in the leg-sweep apparatus10by the collision of the leg portion62against the bumper cover50acts on the vicinity of the shank66of the leg portion62of the pedestrian via the lower protruding portion48of the bumper cover50. As a result, the vicinity of the shank66of the leg portion62of the pedestrian is swept or scooped up by the leg-sweep apparatus10, thereby causing the pedestrian to fall down or to be thrown toward the bonnet52of the vehicle. Thus, it is possible to limit bending of the knee64of the pedestrian in an unnatural or undesirable direction, thereby minimizing occurrence of injuries to the knee64such as bone fractures and effectively assuring protection and safety of the pedestrian.

In the leg-sweep apparatus10according to the exemplary embodiment, in particular, the load-input surface42of the first vertically extending portion34and the load-input surface43of the second vertically extending portion38are located inside of the lower protruding portion48of the bumper cover50so as to be opposed to and located as close as possible to the inner surface of the lower protruding portion48in the frontward and backward direction, thereby effectively reducing a clearance between the inner surface of the lower protruding portion48of the bumper cover50and the front portion14of the base plate12.

Each of the load-input surfaces42,43is disposed so as to be right-angled to the horizontal plane that includes the input direction of the impact load, whereby the impact load is inputted, at right angles, to the load-input surfaces42,43of the respective first and second vertically extending portions34,38. Therefore, in spite of the fact that the lower protruding portion48of the bumper cover50with which the leg portion62of the pedestrian is brought into collision has the convex curved surface configuration in vertical cross section, the front portion14of the base plate12is advantageously prevented from being deformed to be rolled up, for instance, by the impact load inputted to the staircase-like portion40of the base plate12. The arrangement is effective to eliminate or restrain the delay of the rise of the impact load in the load characteristics.

Further, the first horizontally extending portion32and the second horizontally extending portion36are disposed inside of the lower protruding portion48of the bumper cover50so as to be located at the mutually different height levels, so that the portion of the base plate12that horizontally extends is divided into segments, so that moment arm is advantageously shortened, thereby effectively reducing rotation force generated in the base plate12upon inputting of the impact load. Therefore, it is possible to advantageously prevent the front portion14of the base plate12from being deformed to be rolled up, resulting in a prompt rise of the impact load in the load characteristics.

Moreover, because the first and second horizontally extending portions32,36disposed inside of the lower protruding portion48of the bumper cover50so as to be located at the mutually different height positions exhibit sufficient rigidity with respect to the load inputted in the horizontal direction, the counterforce with respect to the impact load can be sufficiently and reliably exhibit in the leg-sweep apparatus10at the two different height positions upon inputting of the impact load accompanied by the collision of the leg portion62of the pedestrian.

Each of the load-input surfaces42,43to which the impact load is inputted is configured to be right-angled to the horizontal plane as mentioned above, thereby advantageously increasing the contact area of the front portion14of the base plate12with the leg portion62of the pedestrian. Therefore, the impact load can be more sufficiently and reliably inputted to the leg-sweep apparatus10. Consequently, the counterforce with respect to the impact load can be exhibited in the leg-sweep apparatus10with a larger magnitude.

Accordingly, in the thus constructed leg-sweep apparatus10, the counterforce with respect to the impact load accompanied by the collision of the leg portion62of the pedestrian against the bumper cover50can instantaneously act on the vicinity of the shank66of the leg portion62with a sufficiently large magnitude even when the leg-sweep apparatus10is disposed inside of the lower protruding portion48of the bumper cover50whose vertical cross sectional shape is the convex curved configuration protruding frontward. Therefore, the leg portion62of the pedestrian which has collided with the bumper cover50can be promptly and reliably swept, so that the leg portion62of the pedestrian can be advantageously protected with high reliability.

Because the leg-sweep apparatus10according to the exemplary embodiment permits a prompt rise of the impact load in the load characteristics, the impact load reaches a target value quickly. Accordingly, the present leg-sweep apparatus10effectively assures a sufficient amount of the impact-absorbing stroke accompanied by buckling deformation of the horizontally extending portions after the impact load in the load characteristics has reached the target value.

In the present leg-sweep apparatus10constructed as described above, the second horizontally extending portion36is located at the front end portion of the staircase-like portion40of the base plate12while the third bend30as the front end of the second horizontally extending portion36is located at the middle portion of the staircase-like portion40in the height direction thereof. The thus constructed leg-sweep apparatus10is disposed inside of the lower protruding portion48of the bumper cover50with the third bend30located at the middle of the lower protruding portion48in its height direction. According to the arrangement, a point of initial contact of the leg-sweep apparatus10with the leg portion62of the pedestrian which is brought into collision with the bumper cover50is the third bend30of the staircase-like portion40, so that the impact load can be inputted, with high reliability in the horizontal direction, to the second horizontally extending portion36, whereby the front portion14of the base plate12is more effectively prevented from being deformed to be rolled up. In consequence, the leg portion62of the pedestrian can be protected with high efficiency and high reliability.

In the exemplary embodiment, the first and second reinforcing ribs18,20for reinforcing the rigidity of the front portion14of the base plate12are formed integrally with the posterior surfaces (the back surfaces) of the load-input surfaces42,43of the respective first and second vertically extending portions34,38and the upper surfaces of the respective first and second horizontally extending portions32,36. According to the arrangement, the rigidity of the extending portions32-38can be advantageously increased, permitting the leg-sweep apparatus10to sufficiently exhibit the counterforce with respect to the impact load. As a result, the leg-sweep apparatus10assures further enhanced performance of protecting the leg portion62of the pedestrian. Moreover, by adjusting the number of the first and second reinforcing ribs18,20and the locations of the same18,20, it is possible to suitably change the rigidity of the front portion14of the base plate12, whereby the amount of buckling deformation of the front portion14of the base plate12accompanied by the input of the impact load can be easily tuned depending upon the magnitude of the impact load to be inputted.

In the exemplary first embodiment, the forward end of the staircase-like portion40of the base plate12is constituted by the second vertically extending portion38that extends straightly in the vertical direction. The forward end of the staircase-like portion40may be constituted by a horizontally extending portion that extends horizontally, as shown in the leg-sweep apparatus ofFIG. 4constructed according to a second embodiment of the invention. In the second embodiment, the same reference numerals as used in the illustrated first embodiment ofFIGS. 1-3are used to identify the corresponding components, and a detailed explanation of which is dispensed with.

In the leg-sweep apparatus10according to the exemplary second embodiment, the leading end part22of the front portion14of the base plate12is in a bent form obtained by bending a flat plate extending straightly in the frontward and backward direction, at right angles in the frontward and backward direction at four locations which are spaced apart from each other by a prescribed distance in the frontward and backward direction, whereby the leading end part22includes, in addition to the first through third bends26-30, a fourth bend68formed over the third bend30. A portion of the leading end part22of the base plate12located on the front side of the fourth bend68(i.e., the forward end of the leading end part22) is bent at right angles from the upper end of the second vertically extending portion38and is made as a third horizontally extending portion70that horizontally and straightly extends in the frontward and backward direction under installation of the leg-sweep apparatus10on the vehicle.

Thus, in the leading end part22of the front portion14of the base plate12, each of the first, second and third horizontally extending portions32,36,70and each of the first and second vertically extending portions34,38are alternately disposed in the frontward and backward direction so as to extend in a staircase-like form, whereby the entirety of the leading end part22is made as a staircase-like portion40constituted by the first, second and third horizontally extending portions32,36,70and the first and second vertically extending portions34,38.

The thus constructed leg-sweep apparatus10having the staircase-like portion40in which the third horizontally extending portion70is additionally provided is disposed at the lower part of the front face of the vehicle so as to be located inside of the lower protruding portion48of the bumper cover50, such that the rear portion16is fixed to the radiator support60by the fixing bolts61, with the staircase-like portion40(the leading end part22) of the front portion14of the base plate12inserted into the interior of the lower protruding portion48.

With the leg-sweep apparatus10installed on the vehicle as described above, in particular, the third horizontally extending portion70horizontally extends toward the inner surface of the lower protruding portion48so as to minimize a clearance formed between the front end face of the third horizontally extending portion70of the staircase-like portion40inserted into the interior of the lower protruding portion48and the inner surface of the lower protruding portion48.

Accordingly, when the leg-sweep apparatus10constructed as described above is disposed inside of the lower protruding portion48of the bumper cover50having, in the vertical cross section, the convex curved surface configuration protruding forward, the clearance formed between the lower protruding portion48and the base plate12is advantageously made small, thereby effectively assuring a prompt rise of the impact load in the load characteristics, so that the leg portion of the pedestrian can be protected with higher reliability.

In addition, the vertically extending portion34extends straightly in the vertical direction of the vehicle, so that the impact load that is imposed upon frontal collision can be received by a plane of the vertically extending portion34, in the horizontal direction. Accordingly, the vertically extending portion34can withstand a higher load, whereby a leg portion of the pedestrian can surely be swept.

It is noted that the respective numbers, the respective dimensions of extension, etc., of the horizontally extending portions32,36,70and the vertically extending portions34,38that constitute the staircase-like portion40are not limited to those in the illustrated first and second embodiments, but may be suitably determined depending upon the desired pedestrian protection performance, more specifically, the magnitude of the counterforce to be exhibited in the pedestrian protection apparatus, the installation space for the pedestrian protection apparatus and the like.

In the illustrated first and second embodiments, in the leading end part22of the front portion14of the base plate12, the portion thereof located on the back side of the first vertically extending portion34is made as the first horizontally extending portion32, and the entirety of the leading end part22including the first horizontally extending portion32is formed as the staircase-like portion40. The staircase-like portion40may be formed by the leading end part22that excludes the first horizontally extending portion32. Namely, a portion of the leading end part22of the front portion14of the base plate12may be formed as the staircase-like portion40. In this case, the staircase-like portion40in the illustrated first embodiment is constituted by the first and second vertically extending portions34,38and the second horizontally extending portion36while the staircase-like portion40in the illustrated second embodiment is constituted by the first and second vertically extending portions34,38and the second and third horizontally extending portions36,70.

The installation structure of the pedestrian protection apparatus (the leg-sweep apparatus10) on the lower part of the front face of the vehicle is not particularly limited. Namely, the portion of the vehicle to which the rear portion of the plate member (the base plate12) is fixed and the manner of fixing may be variously changed. Further, the pedestrian protection apparatus may be disposed at the lower part of the vehicle separately from and independently of the front bumper.

In the illustrated first and second embodiments, among the at least one horizontally extending portion32,36and the plurality of vertically extending portions34,38, those which are located nearer to the forward end of the leading end part22are disposed at higher levels, whereby the staircase-like portion40is formed in a rising or ascending configuration in the frontward direction. On the contrary, among the at least one horizontally extending portion32,36and the plurality of vertically extending portions34,38, those which are located nearer to the forward end of the leading end part22may be disposed at lower levels, whereby the staircase-like portion40is formed in a descending configuration in the frontward direction, further in a configuration ascending or descending in the backward direction from a bent state in which the leading end part22is bent backward.

Each of the anterior surfaces of the vertically extending portions in the staircase-like portion may be constituted by a flat plane orthogonal to the horizontal plane.

The configuration, the location, the number, etc., of the reinforcing ribs provided on the plate member are not particularly limited. The reinforcing ribs are not indispensable in the present invention, and may be eliminated.

Referring next to the plan view ofFIG. 5and the vertical cross sectional view ofFIG. 6, the leg-sweep apparatus as the pedestrian protection apparatus constructed according to a third embodiment of the invention will be explained. In the third embodiment, the same reference numerals as used in the illustrated first and second embodiments are used to identify the corresponding components, and a detailed explanation of which is not given.

As in the illustrated first and second embodiments, the base plate12as the plate portion is formed of the synthetic resin material such as polypropylene or ABS resin. Namely, the base plate12is constituted by a thin planar plate having a generally rectangular shape. In the base plate12, the dimension as measured in a vertical direction ofFIG. 5, i.e., the dimension as measured in the vehicle width direction or the leftward and rightward (lateral) direction of the vehicle under installation of the leg-sweep apparatus10on the vehicle, is made smaller than the vehicle width by a suitable amount, and the dimension as measured in a transverse direction ofFIG. 5, i.e., the dimension as measured in the frontward and backward direction of the vehicle, is made sufficiently smaller the above-indicated direction as measured in the leftward and rightward direction.

As in the illustrated first and second embodiments, the base plate12includes the front portion14and the rear portion16. At the rear end of the rear portion16, the plurality of insertion holes23(here, five insertion holes23) are formed through the thickness thereof into which suitable fixing bolts or the like are insertable, such that the insertion holes23are spaced apart from each other by a prescribed distance in the leftward and rightward direction.

In the leg-sweep apparatus10constructed according to the exemplary third embodiment, the front portion14of the base plate12has a special structure not found in conventional apparatus.

Namely, at a leading end part120of the front portion14of the base plate12, there are provided three vertically extending portions122,124,126which extend straightly in the vertical direction over the entire width of the base plate12such that those vertically extending portions122,124,126are opposed to and spaced apart from each other by a constant distance in the frontward and backward direction. In addition, there are provided two horizontally extending portions128,130which extend straightly in the horizontal direction over the entire width of the base plate12such that the horizontally extending portion128is interposed between the two vertically extending portions122,124while the horizontally extending portion130is interposed between the two vertically extending portions124,126.

More specifically described, the three vertically extending portions122,124,126consist of: a front-side vertically extending portion122which is located at the forward end of the front portion14of the base plate12; a first rear-side vertically extending portion124which is located immediately on the back side of the front-side vertically extending portion122so as to be opposed thereto; and a second rear-side vertically extending portion126which is located on the back side of the first rear-side vertically extending portion124so as to be opposed thereto at a substantially middle of the front portion14as seen in the frontward and backward direction. Each of the front-side, first rear-side and second rear-side vertically extending portions122,124,126has the same width as that of the base plate12, and the same height (the dimension in the vertical direction) with each other. Each vertically extending portion122,124,126is constituted by a thin flat plate having a curved configuration that is deflected or warped so as to be convexed frontward in the thickness direction thereof.

According to the arrangement, the front end surface of the base plate12, i.e., a load-input surface131to which the impact load generated upon collision of the leg portion of the pedestrian against the front face of the vehicle is inputted is constituted by an anterior surface132of the front-side vertically extending portion122. The load-input surface131given by the anterior surface132is made as a curved surface obtained by deflecting or warping a vertical plane which is right-angled with respect to a horizontal plane that includes the input direction of the impact load generated accompanied by the collision of the leg portion of the pedestrian against the front face of the vehicle, such that the vertical plane is gradually curved backward from the middle portion thereof as seen in the leftward and rightward direction toward the opposite end portions thereof as seen in the same direction. Namely, the load-input surface131is constituted as a convex curved surface protruding frontward and formed by a path that is obtained by moving a vertical line so as to draw an arc.

In the meantime, the horizontally extending portions128,130consist of a front-side horizontally extending portion128which is located between the lower ends of the respective front-side and first rear-side vertically extending portion122,124; and a rear-side horizontally extending portion130which is located between the upper ends of the respective first and second rear-side vertically extending portions124,126. Each of the front-side and rear-side horizontally extending portions128,130is constituted by a thin flat plate which has a curved convex configuration protruding frontward in the width direction and corresponding to the anterior and posterior surfaces of the respective vertically extending portions122,124,126and which has a length (i.e., a dimension as measured in the leftward and rightward direction) that is the same as the width of the base plate12and a width (i.e., a dimension as measured in the frontward and backward direction) that is the same as a distance between any adjacent two of the vertically extending portions122,124,126which are opposed to each other.

The lower ends of the respective front-side vertically extending portion122and first rear-side vertically extending portions124are connected integrally to each other by the front-side horizontally extending portion128while the upper ends of the respective first and second rear-side vertically extending portions124,126are connected integrally to each other by the rear-side horizontally extending portion130. The second rear-side vertically extending portion126is connected, at its lower end, integrally to the rear portion16of the base plate12by a connecting portion135which is given by a proximal end part134of the front portion14of the base plate12.

Thus, the front-side vertically extending portion122, the first rear-side vertically extending portion124and the second rear-side vertically extending portion126are formed integrally on the front portion14of the base plate12so as to extend therefrom, such that adjacent two of the vertically extending portions122,124,126that are opposed to each other are connected integrally to each other by a corresponding one of the front-side and rear-side horizontally extending portions128,130that are located at mutually different height levels in the frontward and backward direction.

In other words, in the leg-sweep apparatus10according to the exemplary third embodiment, the leading end part120of the front portion14of the base plate12is in a bent form obtained by bending a flat plate extending straightly in the frontward and backward direction, at right angles at its five locations which are spaced apart from each other by a prescribed distance in the frontward and rightward direction, so as to provide a first bend136, a second bend138, a third bend140, a fourth bend142and a fifth bend144in order as seen from the front side.

In the leading end part120described above, a portion between the fifth bend144located at the rearmost of the leading end part120and the fourth bend142located on the front side of the fifth bend144is made as the second rear-side vertically extending portion126that extends straightly in the vertically upward direction from the front end of the connecting portion135as the proximal end part134of the front portion14of the base plate12. A portion of the leading end part120between the fourth bend142and the third bend140which is located on the front side of the fourth bend142is made as the rear-side horizontally extending portion130that extends straightly in the horizontally forward direction from the upper end of the second rear-side vertically extending portion126. A portion of the leading end part120between the third bend140and the second bend138which is located on the front side of the third bend140is made as the first rear-side vertically extending portion124that extends straightly in the vertically downward direction from the front end of the rear-side horizontally extending portion130. A portion of the leading end part120between the second bend138and the first bend136which is located on the front side of the second bend138is made as the front-side horizontally extending portion128that extends straightly in the horizontally frontward direction from the lower end of the first rear-side vertically extending portion124. An entire portion located on the front side of the first bend136is made as the front-side vertically extending portion122that extends straightly in the vertically upward direction from the front end of the front-side horizontally extending portion128.

Thus, the leading end part120of the front portion14of the base plate12is constituted by the front-side vertically extending portion122, the front-side horizontally extending portion128, the first rear-side vertically extending portion124, the rear-side horizontally extending portion130and the second rear-side vertically extending portion126, so as to extend in the frontward and backward direction in a zigzag form in the upward and downward direction with a U-shaped configuration in vertical cross section.

In the arrangement described above, there is formed, at the front of the leading end part120of the base plate12, a front-side U-shaped portion146that is constituted by the front-side horizontally extending portion128, and the front-side vertically extending portion122and the first rear-side vertically extending portion126which are respectively formed integrally to the front end and the rear end of the front-side horizontally extending portion128such that the vertically extending portions122,126are opposed to each other and extend straightly in the vertically upward direction. The front-side U-shaped portion146has a U-shaped configuration in vertical cross section that is open upward and extends over the entire width of the base plate12. Further, there is formed, at the back of the leading end part120, a rear-side U-shaped portion148that is constituted by the rear-side horizontally extending portion130, and the first and second rear-side vertically extending portions124,126which are respectively formed integrally to the front end and the rear end of the rear-side horizontally extending portion130such that the vertically extending portions124,126are opposed to each other and extend straightly in the vertically downward direction. The rear-side U-shaped portion148has a U-shaped configuration in vertical cross section that is open downward and extends over the entire width of the base plate12. That is, the front-side U-shaped portion146and the rear-side U-shaped portion148are formed integrally on the leading end part120of the front portion14of the base plate12so as to be located continuously in the frontward and backward direction.

Accordingly, in the present leg-sweep apparatus10, the front-side U-shaped portion146and the rear-side U-shaped portion148provided on the leading end part120of the front portion14of the base plate12function as beads which reinforce the front portion14(the leading end part120), thereby increasing the flexural or bending strength of the front portion14. Thus, the rigidity with respect to the impact load to be inputted upon collision of the leg portion of the pedestrian against the front face of the vehicle can be sufficiently obtained, as described below.

Further, on the front portion14of the base plate12, there are formed, each as a reinforcing portion, first through third reinforcing ribs150,152,154which are formed integrally to the upper surface of the front-side horizontally extending portion128, the lower surface of the rear-side horizontally extending portion130and the upper surface of the connecting portion135which is given by the proximal end part134.

Namely, each of the first reinforcing ribs150is a flat plate having the same height as the front-side vertically extending portion122and the first and second rear-side vertically extending portions124,126and the thickness smaller than the thickness of those vertically extending portions122,124,126. The first reinforcing ribs150are opposed to and spaced apart from each other in the leftward and rightward direction by a suitable distance so as to be parallel to each other. The thus located first reinforcing ribs150extend continuously and straightly in the frontward and backward direction so as to be integral with the posterior surface of the front-side vertically extending portion122and the anterior surface of the first rear-side vertically extending portion124.

Each of the second reinforcing ribs152is a flat plate having a height, a thickness and a length (i.e., a dimension as measured in the frontward and backward direction) which are the same as those of the first reinforcing ribs150. The number of the second reinforcing ribs152is the same as that of the first reinforcing ribs150. The second reinforcing ribs152are located between the first-side and second-side vertically extending portions124,126such that the second reinforcing ribs152are opposed to and spaced apart from each other in the leftward and rightward direction by the same distance as the distance between any adjacent two of the first reinforcing ribs150, so as to be parallel to each other. The thus located second reinforcing ribs152extend continuously and straightly in the frontward and backward direction so as to be integral with the posterior surface of the first rear-side vertically extending portion124and the anterior surface of the second rear-side vertically extending portion126. The location of each of the second reinforcing ribs152in the leftward and rightward direction corresponds to the location of each of the first reinforcing ribs150in the same direction.

While each of the third reinforcing ribs154has a height and a thickness which are the same as those of the first and second reinforcing ribs150,152, each third reinforcing rib154has a length (i.e., a dimension as measured in the frontward and backward direction) which is larger than that of the first and second reinforcing ribs150,152. The number of the third reinforcing ribs154is approximately half the number of the first and second reinforcing ribs150,152. The third reinforcing ribs154are located on the back side of the second rear-side vertically extending portion126such that the third reinforcing ribs154are opposed to and spaced apart from each other in the leftward and rightward direction by a distance twice the distance between any adjacent two of the first reinforcing ribs150, so as to be parallel to each other. The thus located third reinforcing ribs154are integral with the posterior surface of the second rear-side vertically extending portion126and extend continuously and straightly in the frontward and backward direction from the posterior surface of the second rear-side vertically extending portion26to a boundary between the front portion14and the rear portion16.

As explained above, the first and second reinforcing ribs150,152are formed, at close intervals, integrally with the leading end part120of the front portion14of the base plate12on which are formed the front-side U-shaped portion146and the rear-side U-shaped portion148, thereby sufficiently increasing the flexural or bending strength of the leading end part120, further, the rigidity of the same120with respect to the impact load. Moreover, the third reinforcing ribs154are formed integrally with the proximal end portion134(the connecting portion135) of the front portion14, whereby the proximal end part134advantageously has increased flexural or bending strength, further, increased rigidity with respect to the impact load, as compared with a case in which the rear portion16of the base plate12has no reinforcing ribs154.

As shown inFIG. 7, the leg-sweep apparatus10is installed inside of the front bumper44which has a structure similar to that explained above with respect to the illustrated first exemplary embodiment.

As in the illustrated first embodiment, the impact-absorbing member56whose rigidity is smaller than that of the leg-sweep apparatus10is fixed, inside of the upper protruding portion46of the bumper cover50, to the bumper reinforcement58as the rigid member.

The leg-sweep apparatus10is disposed inside of the front bumper44as described below: The front-side and rear-side U-shaped portions146,148formed at the leading end part120of the front portion14of the base plate12are projected from the front face of the vehicle, and the front of the front-side U-shaped portion146is inserted into the interior of the lower protruding portion48while the upper surface of the rear end of the rear portion16of the base plate12is held in contact with the lower surface of the radiator support60that is fixedly provided at the front portion of the vehicle so as to extend in the vehicle width direction, for supporting the radiator54. The fixing bolts61are respectively inserted into the plurality of insertion holes23formed at the rear end of the rear portion16of the base plate12and screwed into the radiator support60, whereby the rear portion16of the base plate12is fixed to the radiator support60.

Thus, the leg-sweep apparatus10is disposed in the lower part of the front face of the vehicle so as to extend horizontally in the frontward and backward direction and is fixedly positioned such that the load-input surface131of the front-side vertically extending portion122in the front-side U-shaped portion146of the base plate12is opposed to the inner surface of the lower protruding portion48of the bumper cover50and such that the first bend36which is the lower end of the front-side vertically extending portion122and which is the front end of the front-side horizontally extending portion128is located adjacent to the inner surface of the lower protruding portion48of the bumper cover50.

As described above with respect to the illustrated first embodiment, in the exemplary third embodiment, when the leg portion62of the pedestrian comes into contact or collides with the bumper cover50of the front bumper44as shown inFIG. 8, the upper protruding portion46and the lower protruding portion48of the bumper cover50are respectively brought into contact with the vicinity of the knee64and the vicinity of the shank66of the leg portion62of the pedestrian. In this instance, since the rigidity of the impact-absorbing member56is made smaller than that of the leg-sweep apparatus10, the impact-absorbing member56is deformed more easily in a larger amount than the leg-sweep apparatus10. Accordingly, the bumper cover50is deformed such that lower protruding portion48projects frontward of the vehicle farther than the upper protruding portion46, so that the counterforce with respect to the impact load generated in the leg-sweep apparatus10by the collision of the leg portion62against the bumper cover50acts on the vicinity of the shank66of the leg portion62of the pedestrian via the lower protruding portion48of the bumper cover50. As a result, the vicinity of the shank66of the leg portion62of the pedestrian is swept or scooped up by the leg-sweep apparatus10, thereby causing the pedestrian to fall down or to be thrown toward the bonnet52of the vehicle. Thus, it is possible to limit bending of the knee64of the pedestrian in an unnatural or undesirable direction, thereby minimizing occurrence of injuries to the knee64such as bone fractures and effectively assuring protection and safety of the pedestrian.

In particular, the leg-sweep apparatus10constructed as described above has, at the leading end part120of the front portion14of the base plate12, the front-side U-shaped portion146and the rear-side U-shaped portion148each functioning as a bead for reinforcing the leading end part120. In addition, the first through third reinforcing ribs150-154are formed integrally with the leading end part120and the proximal end part134, whereby the rigidity of the front portion14as a whole with respect to the impact load is sufficiently obtained. Therefore, the front portion14of the base plate12is effectively prevented from being easily deformed or deflected due to the impact load inputted thereto.

In the leg-sweep apparatus10constructed as described above, the load-input surface131of the front-side vertically extending portion122which is located so as to be opposed to the inner surface of the lower protruding portion48of the bumper cover50is orthogonal to the horizontal plane that includes the input direction of the impact load, whereby the impact load is inputted perpendicularly to the load-input surface131. Accordingly, the front portion14of the base plate12can be advantageously prevented from being easily deformed or deflected.

Further, the front-side and rear-side horizontally extending portions128,130of the respective front-side and rear-side U-shaped portions146,148are located at mutually different height levels. Accordingly, the portion of the base plate12that horizontally extends is divided into: a continuous portion between the proximal end portion134of the front portion14and the rear portion16; the front-side horizontally extending portion128; and the rear-side horizontally extending portion130. Accordingly, the moment arm can be advantageously shortened, and the rotation force generated in the base plate12upon inputting of the impact load is effectively weakened, thereby assuring the effect of preventing easy deformation or deflection of the front portion14of the base plate12.

In the leg-sweep apparatus10constructed as described above according to the third exemplary embodiment, the front-side U-shaped portion146and the rear-side U-shaped portion148are formed continuously, so that the leading end part120of the front portion14of the base plate12has, as a whole, a zigzag configuration shown inFIG. 6extending in the frontward and backward direction. Accordingly, as shown inFIG. 7, due to the impact load inputted to the front-side vertically extending portion122of the front-side U-shaped portion146, the front-side and rear-side horizontally extending portions128,130of the respective front-side and rear-side U-shaped portions146,148are displaced backward while the impact load is gradually transmitted from the front portion14toward the rear portion16of the base plate12. In this instance, the first and second rear-side vertically extending portions124,126of the respective front-side and rear-side U-shaped portion146,148are deformed over a wide range in the width direction of the base plate12, such that those vertically extending portions124,126incline frontward or backward by a suitable angle with respect to the vertical direction. Therefore, the impact load is effectively transmitted in the width direction of the base plate12. Consequently, the impact load is advantageously distributed in the front portion14of the base plate12, whereby the front portion14of the base plate12is effectively prevented from easily deformed or deflected upon inputting of the impact load thereto.

As explained above, in the present embodiment, the easy deformation or deflection of the front portion14of the base plate12upon inputting of the impact load thereto can be prevented, thereby obviating a delay of rise of the impact load in the load characteristics due to deformation or deflection of the front portion14of the base plate12.

Accordingly, the present leg-sweep apparatus10permits a prompt rise of the impact load in the load characteristics, whereby sufficient counterforce with respect to the impact load can be instantaneously and adequately exhibited. As a result, the leg portion62of the pedestrian which has collided with the front bumper44can be instantaneously and reliably swept, assuring a higher level of protection of the leg portion62of the pedestrian.

Since the present leg-sweep apparatus10permits a prompt rise of the impact load in the load characteristics, the impact load can reach a target value more quickly. Consequently, the present leg-sweep apparatus10effectively assures a sufficient amount of the impact-absorbing stroke accompanied by buckling deformation off the horizontally extending portions128,130, the connecting portion135, etc., after the impact load in the load characteristics has reached the target value.

In the exemplary third embodiment, the first through third reinforcing ribs150-154are formed integrally with the front portion14of the base plate12for increasing the rigidity of the same14. As compared with an arrangement in which the rigidity of the front portion14is increased by securing, to the base plate12, members separate from the base plate12, for instance, the present arrangement is effective to improve the manufacturing efficiency and lower the manufacturing cost of the base plate12, and accordingly the leg-sweep apparatus10as a whole. Moreover, by adjusting the number, the location, etc., of each of the first through third reinforcing ribs150-154, the rigidity of the front portion14of the base plate12can be suitably changed, thereby making it possible to easily tune, depending upon the magnitude of the impact load to be inputted, the amount of buckling deformation of the front portion14of the base plate12accompanied by the input of the impact load, and accordingly the amount of absorption of impact energy based on the buckling deformation of the front portion14.

In the illustrated third embodiment, the leading end part120of the front portion14of the base plate12is provided with the two U-shaped portions146,148which are continuously formed thereon. The leading end part120may have only one U-shaped portion84, as shown in the leg-sweep apparatus ofFIG. 9according to a fourth embodiment of the invention. In the fourth embodiment, the same reference numerals as used in the embodiments illustrated above are used to identify the corresponding components, and a detailed explanation of which is omitted.

In the leg-sweep apparatus10according to the fourth embodiment shown inFIG. 9, a front-side vertically extending portion86and a rear-side vertically extending portion88which straightly extend in the vertical direction over the entire width of the base plate12are integrally formed on the leading end part120of the front portion14of the base plate12, such that the vertically extending portions86,88are opposed to and spaced apart from each other by a constant distance in the frontward and backward direction. Those front-side and rear-side vertically extending portions86,88have a construction similar to that of the front-side and rear-side vertically extending portions (22), (24) in the illustrated third embodiment.

According to the arrangement described above, the anterior surface90of the front-side vertically extending portion86is made as a load-input surface131constituted by a curved surface obtained by deflecting or warping a vertical plane which is right-angled with respect to the horizontal plane that includes the direction of input of the impact load generated upon collision of the leg portion62of the pedestrian against the front bumper44, such that the vertical plane is gradually curved backward from the middle portion thereof as seen in the leftward and rightward direction toward the opposite end portions thereof as seen in the same direction. Namely, the load-input surface131is constituted by a convex curved surface which protrudes forward and which is formed by a path that is obtained by moving a vertical line so as to draw an arc.

Further, between the upper ends of the respective front-side and rear-side vertically extending portions86,88, there is located a horizontally extending portion94which straightly extends in the horizontal direction over the entire width of the base plate12in the frontward and backward direction, whereby the upper ends of the respective front-side and rear-side vertically extending portions86,88are connected integrally to each other by the horizontally extending portion94. A connecting portion135constituted by a proximal end part134of the front portion14of the base plate12is connected integrally to the lower end of the posterior surface of the rear-side vertically extending portion88, which posterior surface is opposite to the anterior surface thereof to which the horizontally extending portion94is connected.

In other words, in the exemplary fourth embodiment, the horizontally extending portion94is located at the leading end part120of the front portion14of the base plate12, and the front-side vertically extending portion86is formed integrally with the front end of the horizontally extending portion94so as to straightly extend therefrom in the vertically downward direction. Further, the rear-side vertically extending portion88is formed integrally with rear end of the horizontally extending portion94such that the rear-side vertically extending portion88is opposed to and spaced apart from the front-side vertically extending portion86with a distance corresponding to the length of extension of the horizontally extending portion94interposed therebetween, so as to extend straightly in the vertically downward direction. The connecting portion135is connected, at its front end, integrally to the lower end of the posterior surface of the rear-side vertically extending portion88.

Thus, at the leading end part120of the front portion14of the base plate12, there is formed a U-shaped portion84constituted by the front-side vertically extending portion86, the horizontally extending portion94and the rear-side vertically extending portion88and extending over the entire width of the base plate12with a U-shaped configuration that is open downward in vertical cross section.

In the thus constructed leg-sweep apparatus10, the U-shaped portion84functions as a bead for reinforcing the leading end part120of the front portion14of the base plate12, thereby sufficiently assuring the flexural or bending strength of the leading end part120and accordingly the rigidity of the same120with respect to the impact load.

In addition, the horizontally extending portion94and the connecting portion135are located at mutually different height levels, so that the moment arm can be advantageously shortened, and the rotation force generated in the plate member upon inputting of the impact load is effectively weakened, thereby assuring the effect of preventing the leading end part of the plate member from being deformed to be rolled up.

On the lower surface of the horizontally extending portion94which partially constitutes the U-shaped portion84, there are provided a plurality of front-side reinforcing ribs96that are similar in construction to the first and second reinforcing ribs (150), (152) described in the illustrated third embodiment. The reinforcing ribs96are thin flat plates and are spaced apart from each other by a suitable distance in the leftward and rightward direction, so as to be integral with the posterior surface of the front-side vertically extending portion86and the anterior surface of the rear-side vertically extending portion88. Moreover, on the upper surface of the connecting portion135constituted by the proximal end part134of the front portion14of the base plate12, there are provided a plurality of rear-side reinforcing ribs98that are similar in construction to the third reinforcing ribs (154) described in the illustrated third embodiment. The rear-side reinforcing ribs98are thin flat plates and are spaced apart from each other by a suitable distance in the leftward and rightward direction, so as to be integral with the posterior surface of the rear-side vertically extending portion88. According to the arrangement, the rigidity of the front portion14of the base plate12with respect to the impact load is more efficiently enhanced.

As in the illustrated third embodiment, the thus constructed leg-sweep apparatus10is disposed at the lower part of the vehicle with the front of the U-shaped portion84inserted and projected into the lower protruding portion48of the bumper cover50of the front bumper44.

Accordingly, as the present leg-sweep apparatus10assures sufficient rigidity with respect to the impact load, so that the front portion14of the base plate12is effectively prevented from being easily deflected upon collision of the leg portion62of the pedestrian against the front bumper44.

Further, when the impact load is inputted, the horizontally extending portion94of the U-shaped portion84is displaced backyard while the front-side and rear-side vertically extending portions86,88are deformed over a wide range in the width direction of the base plate12so as to be inclined frontward or backward by a suitable angle with respect to the vertical direction. Accordingly, the impact load is effectively transmitted in both of the length direction and the width direction of the base plate and advantageously distributed in the front portion14of the base plate12, preventing easy deflection of the front portion14of the base plate12due to the impact load inputted thereto.

Therefore, the leg-sweep apparatus10constructed as described above permits a prompt rise of the impact load in the load characteristics, thereby exhibiting sufficient counterforce with respect to the impact load at earlier timing. Consequently, the leg portion62of the pedestrian collided with the front bumper44can be promptly and reliably swept, so that the performance of protecting the leg portion of the pedestrian can be effectively enhanced.

In the leg-sweep apparatus10constructed as described above, only one U-shaped portion84is formed at the front portion14of the base plate12, simplifying the structure of the base plate12, and accordingly the structure of the leg-sweep apparatus10as a whole.

Referring next toFIG. 10, there will be explained a modified structure of the leg-sweep apparatus according to a fifth embodiment of the invention. In the exemplary fifth embodiment, while only one U-shaped portion84is formed at the leading end part120of the front portion14of the base plate12as in the illustrated fourth embodiment, the front-side vertically extending portion86of the U-shaped portion84has a special structure. Further, in the exemplary fifth embodiment shown inFIG. 10, the U-shaped portion84has a U-shaped configuration that is open upward. In the fifth embodiment, the same reference numerals as used in the illustrated embodiments are used to identify the corresponding components, and a detailed explanation of which is dispensed with.

In the leg-sweep apparatus10shown inFIG. 10, the front-side vertically extending portion86is bent at right angles at two locations in its height direction, so as to extend frontward in a staircase-like form.

In other words, front-side vertically extending portion86is divided into an upper front-side vertically extending portion100and a lower front-side vertically extending portion102which have mutually the same height dimension. The upper front-side vertically extending portion100and the lower front-side vertically extending portion102are positioned at mutually different height levels such that the former100is located frontward of the latter102. These upper and lower front-side vertically extending portions100,102are connected integrally to each other by an intermediate horizontally extending portion104that extends horizontally in the frontward and backward direction between the lower end of the upper front-side vertically extending portion100and the upper end of the lower front-side vertically extending portion102.

According to the arrangement, the front of the U-shaped portion84provided at the leading end part120of the front portion14of the base plate12is constituted as a staircase-like portion, and an anterior surface106of the upper front-side vertically extending portion100of the staircase-like portion is made as the load-input surface131that straightly extends in the vertical direction. A horizontal projection108projecting in the horizontal direction by a prescribed amount is formed integrally with the load-input surface131. The horizontal projection108is a rib formed of a thin, flat plate having the same thickness as that of the upper and lower front-side vertically extending portions100,102.

In the present leg-sweep apparatus10constructed as described above, the entirety of the front portion14of the base plate12except for the leading end part120on which is formed the U-shaped portion84is made as the proximal end part134. The proximal end part134is made as the connecting portion135which connects the rear-side vertically extending portion88of the U-shaped portion84and the rear portion16of the base plate12integrally to each other. The connecting portion135consists of: a rear part which extends horizontally and frontward from the rear portion16of the base plate; an intermediate part which extends frontward and obliquely upward from the front end of the rear part; and a front part which extends horizontally and frontward from the front of the intermediate part and which is connected integrally to a middle portion of the posterior surface of the rear-side vertically extending portion88of the U-shaped portion84in the height direction thereof.

On the thus constructed front portion14of the base plate12, there are formed a plurality of front-side reinforcing ribs96and a plurality of rear-side reinforcing ribs98each of which is a thin flat plate, as in the illustrated fourth embodiment. Here, the front-side reinforcing ribs96consist of: a plurality of upper front-side reinforcing ribs96awhich are formed on the upper surface of the horizontally extending portion94of the U-shaped portion84and which are integral with the posterior surfaces of the respective upper and lower front-side vertically extending portions100,102, the upper surface of the intermediate horizontally extending portion104and the anterior surface of the rear-side vertically extending portion88; and a plurality of lower front-side reinforcing ribs96bwhich are formed on the lower surface of the intermediate horizontally extending portion104of the U-shaped portion84and the lower surface of the horizontal projection108and which are integral with the anterior surface of the lower front-side vertically extending portion102. Each of the lower front-side reinforcing ribs96bhas a triangular shape. The rear-side reinforcing ribs98consist of: a plurality of upper rear-side reinforcing ribs98awhich are formed on the upper surface of the connecting portion135and which are integral with the upper part of the posterior surface of the rear-side vertically extending portion88; and a plurality of lower rear-side reinforcing ribs98bwhich are formed on the lower surfaces of the intermediate and front parts of the connecting portion135and which are integral with the lower part of the posterior surface of the rear-side vertically extending portion88.

The leg-sweep apparatus10constructed as described above is disposed inside of the bumper cover50such that the upper front-side vertically extending portion100, the lower front-side vertically extending portion and the intermediate horizontally extending portion104which cooperate with each other to form the staircase-like portion in the front of the U-shaped portion84are inserted into the interior of the lower protruding portion48of the bumper cover50of the front bumper44. In a state in which the leg-sweep apparatus10is disposed as described above, the load-input surface131of the upper front-side vertically extending portion100is located so as to be opposed to the inner surface of the lower protruding portion48having the convex curved surface protruding forward, via a slight clearance therebetween with the horizontal projection108interposed between the inner surface of the lower protruding portion48of the bumper cover50and the load-input surface131. Further, the upper and lower front-side vertically extending portions100,102have the mutually same height dimension, whereby the intermediate horizontally extending portion104of the staircase-like portion which is inserted into the interior of the lower protruding portion48of the bumper cover50is located at a middle of the lower protruding portion48in its height direction. Thus, the leg-sweep apparatus10is fixedly positioned in a manner similar to that described in the illustrated embodiments.

As mentioned above, in the leg-sweep apparatus10according to the exemplary fifth embodiment, the U-shaped portion84and the reinforcing ribs96,98are provided on the front portion14of the base plate12, whereby the front portion14has sufficient rigidity with respect to the impact load while, at the same time, the impact load can be effectively transmitted in the length direction and the width direction of the front portion14of the base plate12. Therefore, the front portion14of the base plate12can be effectively prevented from being easily deformed or deflected by the impact load upon collision of the leg portion62of the pedestrian collided with the bumper cover50.

In the state in which the leg-sweep apparatus10is disposed inside of the bumper cover50of the front bumper44as described above, the intermediate horizontally extending portion104of the staircase-like portion which is inserted into the interior of the lower protruding portion48of the bumper cover50is located at a middle of the lower protruding portion48in its height direction, so that a point of initial contact of the leg-sweep apparatus10with the leg portion62of the pedestrian is the front end of the intermediate horizontally extending portion104of the staircase-like portion provided on the front portion14of the base plate12. Accordingly, the impact load is inputted, with high reliability, in the horizontal direction to the front portion14of the base plate12, effectively avoiding easy deflection of the front portion14.

Therefore, the present leg-sweep apparatus10advantageously avoids a delay of the rise of the impact load in the load characteristics due to the deflection of the front portion14of the base plate12by the impact load inputted thereto.

Further, in the state in which the leg-sweep apparatus10is disposed inside of the bumper cover50of the front bumper44as described above, the load-input surface131of the upper front-side vertically extending portion100is opposed to the inner surface of the lower protruding portion48of the bumper cover50with a slight clearance therebetween. In addition, the horizontal projection108formed integrally on the load-input surface131is located between the load-input surface131and the inner surface of the lower protruding portion48of the bumper cover50. According to the arrangement, even where the inner surface of the lower protruding portion48of the bumper cover50has the convex curved surface configuration that protrudes frontward, it is possible to effectively eliminate or restrain the delay of the rise of the impact load in the load characteristics due to the existence of the clearance between the inner surface of the lower protruding portion48and the front portion14of the base plate12.

In the present leg-sweep apparatus10, therefore, sufficient counterforce with respect to the impact load can be exhibited at earlier timing, so that the leg portion62of the pedestrian collided with the front bumper44can be quickly and reliably swept, assuring more enhanced performance of protecting the leg portion of the pedestrian.

As the horizontally extending portions128,130and the rear-side U-shaped portions146,148are located at mutually different height levels, the moment arm can be advantageously shortened, and the rotation force generated in the plate member upon inputting of the impact load is effectively weakened, thereby assuring the effect of preventing the leading end part of the plate member from being deformed to be rolled up.

The leg-sweep apparatus10according to the illustrated third through fifth embodiments may be otherwise embodied.

For instance, the number of the rear-side vertically extending portions124,126,88provided at the front portion14of the base plate12as the plate member on the back side of the front-side vertically extending portion122,86is not limited to those in the illustrated third through fifth embodiments, but may be three or more.

The thickness and the height of the front-side vertically extending portion122,86may be made different from those of the rear-side vertically extending portion124,126,88.

Further, the number of the horizontally extending portion each connecting adjacent two of the rear-side vertically extending portions124,126,88that are opposed to each other may be suitably increased or decreased depending upon the number of the rear-side vertically extending portions.

The number of the rear-side vertically extending portions124,126,88and the number of the horizontally extending portions128,130,94may be suitably determined depending upon the degree of rigidity of the front portion14of the base plate12with respect to the impact load, the installation space for the pedestrian protection apparatus, etc.

Further, a connection point of the connecting portion to the rear-side vertically extending portion may be suitably determined among any point of the posterior surface of the rear-side vertically extending portion which is located at a different height level from a connection point of the anterior surface of the rear-side vertically extending portion to the horizontally extending portion, depending upon the installation space for the pedestrian protection apparatus, etc.

Where the plurality of horizontally extending portions are respectively located between the front-side vertically extending portion and the rear-side vertically extending portion which is opposed thereto and between adjacent two of the vertically extending portions which are opposed to each other, for connecting the mutually opposing vertically extending portions to each other, namely, where there are provided a plurality of U-shaped portions, connection points of each horizontally extending portion with respect to each vertically extending portion are not limited to the mutually corresponding ends or edges of each vertically extending portion as in the illustrated embodiments, but may be mutually corresponding end portions of each vertically extending portion nearer to the middle than the end or edges, as long as adjacent two of the plurality of horizontally extending portions are located at mutually different height levels.

Where only one U-shaped portion is provided, namely, where the front-side and rear-side vertically extending portions are respectively formed integrally with the front end and rear end of one horizontally extending portion, the front-side and rear-side vertically extending portions may not be formed integrally with the respective front and rear ends or edges of the horizontally extending portion as in the illustrated embodiments, but at least one of the front-side and rear-side vertically extending portions may be provided at an end portion of the horizontally extending portion nearer to the middle than the front end or the rear end thereof, for instance. Further, where the front-side and rear-side vertically extending portions are respectively provided at the front and rear ends of the horizontally extending portion, at least one of the front-side and rear-side vertically extending portions may be made integral, at an end portion thereof nearer to the middle than the vertically opposite ends thereof, with the corresponding one of the front and rear ends of the horizontally extending portion.

In other words, where one or plurality of U-shaped portion(s) is/are formed on the leading end part of the front portion of the plate member (the base plate), each U-shaped portion may not be constituted by combining the entirety of each vertically extending portion and the entirety of each horizontally extending portion, but may be constituted by combining a part of each vertically extending portion and a part of each horizontally extending portion.

The installation structure of the pedestrian protection apparatus on the lower part of the front face of the vehicle is not particularly limited to that in the illustrated embodiments. Namely, the portion of the vehicle to which the rear portion of the plate member is fixed and the manner of fixing may be variously changed. Further, the pedestrian protection apparatus may be disposed at the lower part of the vehicle separately from and independently of the front bumper.

The anterior surface of the front-side vertically extending portion functioning as the load-input surface131may be constituted by a flat plane that is orthogonal to the horizontal plane.

Where the front-side vertically extending portion is bent at substantially right angles at a plurality of locations in the middle portion thereof in the height direction so as to have the staircase-like form extending in the vertical direction, the front-side vertically extending portion may be bent at right angles at three or more locations in its height direction. The bending angle may be somewhat larger or smaller than 90°.

The staircase-like portion formed by bending the front-side vertically extending portion as described above may be in a descending configuration in the forward direction, or in a configuration ascending or descending configuration in the backward direction from a bent state in which the front-side vertically extending portion is bent backward, in addition to the illustrated ascending configuration in the forward direction.

In the illustrated third through fifth embodiments, the reinforcing ribs150,152,154,96,98are formed as reinforcing portions on the front portion14of the base plate12. The structure of the reinforcing portions is not particularly limited, provided that the reinforcing portions are capable of preventing easy deformation of the front portion14of the base plate12due to the impact load inputted thereto accompanied by the collision of the leg portion of the pedestrian against the front face of the vehicle. Where the reinforcing portions are constituted by the illustrated reinforcing ribs150,152,154,96,98, the configuration, the location, the number, etc., of the reinforcing ribs may be suitably changed. Further, the reinforcing portions are not indispensable in the present invention, and may be eliminated.

In the illustrated first through fifth embodiments, the counterforce with respect to the impact load generated in the leg-sweep apparatus10by the collision of the leg portion62of the pedestrian against the bumper cover50is arranged to act on the vicinity of the shank66of the leg portion62of the pedestrian via the lower protruding portion48of the bumper cover50. The portion of the leg portion62of the pedestrian on which the counterforce with respect to the impact load acts may be suitably changed depending upon the installation position of the leg-sweep apparatus10.

It is needless to mention that the principle of the invention is applicable to any pedestrian protection apparatus installed in various forms on the front face of vehicles other than the automotive vehicles.

It is to be understood that the present invention may be embodied with various other changes and modifications which may occur to those skilled in the art, without departing from the spirit and scope of the invention defined in the following claims.

EXAMPLES

To further clarify the present invention, there will be explained examples of the invention. It is to be understood that the invention is not limited to the details of the examples.

Initially, there was prepared, by carrying out injection molding using polypropylene, a leg-sweep apparatus (10) shown inFIG. 9of the present invention. In the leg-sweep apparatus, a front portion (14) of a flat base plate (12) is provided with a U-shaped portion (84) consisting of a front-side vertically extending portion (86), a rear-side vertically extending portion (88) and a horizontally extending portion (94). Further, a plurality of reinforcing ribs (96,98) are formed integrally on the front portion (14), and an anterior surface of the front-side vertically extending portion (86) is made as a load-input surface (131). The thus prepared leg-sweep apparatus is made as the invention example. In the leg-sweep apparatus of the invention example, the maximum length of the base plate in the frontward and backward direction is 300 mm and the width of the base plate is 1200 mm. The height of the front-side and rear-side vertically extending portions is 25 mm, and the length of the horizontally extending portion is 15 mm. The thickness of the base plate and each extending portion is 3 mm. Each reinforcing rib has a height of 25 mm and a thickness of 1.5-3 mm.

For comparison, apart from the leg-sweep apparatus of the invention example, there is prepared, by carrying out injection molding using polypropylene, a leg-sweep apparatus having a known structure. In the leg-sweep apparatus, a plurality of first ribs are formed integrally on a front portion of a flat base plate such that the first ribs extend in the length direction of the base plate and such that the first ribs are opposed to and spaced apart from each other in the width of the base plate by a suitable distance. Further, a second rib extending in the width direction is formed integrally on the front portion so as to intersect the plurality of first ribs. In the thus formed leg-sweep apparatus, the forward end face of the base plate is made as a load-input surface. This leg-sweep apparatus is made as a comparative example. The maximum length of the base plate as measured in the frontward and backward direction and the width of the base plate are made equal to those in the leg-sweep apparatus of the invention example. The height and the thickness of each of the first ribs and the second rib are made equal to those of the reinforcing ribs in the leg-sweep apparatus of the invention example.

The thus prepared leg-sweep apparatus of the invention example and the leg-sweep apparatus of the comparative example were installed on a fixedly positioned base. Thereafter, an impactor having a semi-cylindrical shape and a weight of 21.3 kg was brought into collision with each of the load-input surfaces of the two leg-sweep apparatus according to the invention example and the comparative example, at a rate of 5.3 m/s. Thus, there were conducted pedestrian collision tests on the supposition of a collision of a pedestrian with each leg-sweep apparatus, whereby there were examined, for each apparatus, the portion of the apparatus deformed by the impact load inputted upon collision of the pedestrian and the amount of deformation of the portion, according to CAE analysis. The simulation results by the CAE analysis of the leg-sweep apparatus of the invention example and the comparative example are shown inFIG. 11andFIG. 12, respectively. InFIGS. 11 and 12, the difference in the deformation amount in local portions of each apparatus is indicated by shading.

As shown inFIGS. 11 and 12, it is observed that the portion deformed by the impact load inputted upon collision of the pedestrian is distributed more widely at the front portion of the base plate in the leg-sweep apparatus of the invention example than in the leg-sweep apparatus of the comparative example. This clearly indicates that the leg-sweep apparatus having the structure according to the present invention permits the impact load to be distributed in a wide range at the front portion of the base plate, thereby effectively preventing deflection of the front portion of the base plate due to the impact load inputted thereto.