Collision energy absorbing structure of vehicle body upper portion of automobile

Abstract: A collision energy absorbing structure of a vehicle body upper portion of an automobile having a roofside rail (20) extending in the forward and backward direction and formed to be a closed structure with an outer panel (30) and an inner panel (32) includes a metal energy absorbing panel (22) and a resin interior trim material (24). The energy absorbing panel (22) has a thickness smaller than the thicknesses of the outer panel (30) and the inner panel (32) and is arranged with a space (D) inward of the inner panel. The terminal portion in the longitudinal direction of the energy absorbing panel (22) has a tendency that energy absorption reduces but the tendency is compensated by resin material (26, 28).

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention: This invention relates to a collision energy absorbing structure of a vehicle body upper portion of an automobile, and more particularly to a collision energy absorbing structure of a vehicle body upper portion of an automobile having a structural member extending in the longitudinal direction such as a roofside rail or a header, and an interior trim material such as a roofside garnish or a ceiling trim. 2. Description of the Related Art: There is proposed a collision energy absorbing structure of a vehicle body upper portion of an automobile according to the preamble of claim 1 comprising a structural member extending in the longitudinal direction and formed as a closed structure with flanges respectively of an outer panel and an inner panel joined, the inner panel being arranged with a space inward relative to the outer panel, as viewed from an interior of a passenger compartment, that is, inward of the outer panel in JP-A-7 246 953. The one related to this proposal comprises a metal energy absorbing panel having a small wall thickness than that of the outer panel and that of the inner panel, arranged with a space inward of the inner panel, and joined to the flange portions of the structural member. In the collision absorbing structure relative to the above-mentioned proposal using a metal energy absorbing panel, there occurs no uncrushed portion which is caused when an energy absorbing body such as a resin lattice is used, all the portions except the end terminal portion of the energy absorbing panel can be perfectly and sufficiently deformed, thereby ensuring a predetermined amount of energy absorption. SUMMARY OF THE INVENTION Because of a restriction in structural matter or in production, the above-mentioned energy absorbing panel is sometimes formed to cover the interior of the inner panel of the structural member over a predetermined length in the longitudinal direction, instead of the entire length in the longitudinal direction of the structural member, and attached to the structural member. When the relation between the amount of energy absorption and the distance from the terminal is indicated graphically as a result of colliding a test head form against the terminal part of the energy absorbing panel, it turned out as shown in Fig. 7(a) that within a certain range from a terminal part E 1 an amount of energy absorption EA gradually decreases toward the terminal part E 1 . The range D is substantially 90 mm in case of using a steel plate of 0.4 - 0.8 mm thickness as an energy absorbing panel, as shown in Fig. 7(d). It is considered that this is because the rigidity of the energy absorbing panel is reduced toward the terminal part. As mentioned above, therefore, in case the energy absorbing panel does not cover the entire length of the structural member, it is likely that a great collision force should be exerted to the terminal part of the energy absorbing panel from the structural member. An object of the present invention is to provide a collision energy absorbing structure of a vehicle body upper portion of an automobile, capable of compensating a reduction in an amount of energy absorption of the terminal part of an energy absorbing panel. This object is achieved by the features of the characterizing portion of claim 1. Further developments are set forth in the dependent claims. In one aspect of the present invention, the energy compensating means includes first energy absorbing means provided in the interior trim material in the longitudinal extension of the energy absorbing panel. For the energy absorbing means, a resin lattice or urethane foam may be used. In one embodiment, the energy compensating means further includes second energy absorbing means formed separately from the energy absorbing panel and the first energy absorbing means and arranged to adjoin the terminal portion of the energy absorbing panel and the first energy absorbing means. In another embodiment, the energy compensating means is formed by the first energy absorbing means adjacent to the terminal portion of the energy absorbing panel and a reinforcing structure provided at the terminal portion of the energy absorbing panel. In another aspect of the present invention, the energy compensating means includes a metal second energy absorbing panel having substantially the same sectional configuration and substantially the same thickness as those of the energy absorbing panel. The second energy absorbing panel is arranged in the longitudinal direction of the energy absorbing panel through second energy compensating means which also compensates the amount of energy absorption at its own terminal portion of the second energy absorbing panel and joined to the flange portions of the structural member. The two energy absorbing panels respectively have an abdominal portion arranged with the third space from the inner panel, and flange portions connected to the abdominal portion. In one embodiment, the second energy compensating means is formed to be a structure wherein the abdominal portions are not joined but the terminal portion of the second energy absorbing panel is overlapped on the terminal portion of the energy absorbing panel. In another embodiment, the second energy compensating means is formed to be a structure wherein the second energy absorbing panel is arranged adjacent to the energy absorbing panel so that the terminal portion of the second energy absorbing panel is not overlapped on the terminal portion of the energy absorbing panel, and wherein the abdominal portions of the two energy absorbing panels are joined at one portions of the respective abdominal portions. According to the invention, when a collision force of more than a predetermined one directed outward of a passenger compartment is exerted from an interior trim material to the metal energy absorbing panel, the energy absorbing panel is deformed to absorb the collision energy. When the collision force is exerted to the terminal part of the energy absorbing panel, the energy absorbing panel and the energy compensating means are deformed to compensate the amount of energy reduction of the terminal part. In the metal energy absorbing panel, since an energy absorbing characteristic wherein the rising of a load relative to an amount of stroke is rapid is obtained, an energy absorption that meets a collision force can be attempted by a small amount of stroke, that is, an amount of displacement and a small peak load. Also, as a result of the metal energy absorbing panel being joined to the flange joint portion of the structural member, it can contribute to an improvement in the rigidity of the structural member. Since the reduction in the amount of energy absorption at the terminal part of the energy absorbing panel is compensated by the energy compensating means, the range of absorbing the collision energy by the energy absorbing panel can be broadened. The aforementioned or other objects, characteristics and effects of the present invention will become clear from the following detailed description with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of one embodiment of the collision energy absorbing structure of a vehicle body upper portion of an automobile relative to the present invention, viewed in the direction 1 in Fig. 4. Fig. 2 is a sectional view taken along the line 2 - 2 of Fig. 1. Fig. 3 is a sectional view of one embodiment of the collision energy absorbing structure of a vehicle body upper portion of an automobile relative to the present invention taken along the line 3 - 3 of Fig. 4. Fig. 4 is a side view of the collision energy absorbing structure of a vehicle body upper portion of an automobile relative to the present invention, viewed from the vehicle interior of the automobile. Fig. 5 shows another embodiment of the collision energy absorbing structure of a vehicle body upper portion of an automobile relative to the present invention, in which (a) is a perspective view of the energy absorbing panel and (b) is a sectional view taken along the line b - b of (a), also including an interior trim material. Fig. 6 shows still another embodiment of the collision energy absorbing structure of a vehicle body upper portion of an automobile relative to the present invention, in which (a) is a perspective view of the energy absorbing panel and (b) is a sectional view taken along the line b - b of (a), also including the interior trim material. Fig. 7 is a graph showing the relation between the amount of energy absorption of the energy absorbing panel and the energy absorbing means and the distance from the terminal, typically or schematically showing: (a) the energy absorbing panel; (b) the energy absorbing means arranged to be adjacent to the energy absorbing panel; (c) the energy absorbing panel combined with the energy absorbing means; and (d) a result of an experiment of the energy absorbing panel. Fig. 8 shows still another embodiment of the collision energy absorbing structure of a vehicle body upper portion of an automobile relative to the present invention, in which (a) is a perspective view of the energy absorbing panel and (b) is a sectional view taken along the line b - b of (a), also including the interior trim material. Fig. 9 shows still another embodiment of the collision energy absorbing structure of a vehicle body upper portion of an automobile relative to the present invention, in which (a) is a perspective view of the energy absorbing panel and (b) is a sectional view taken along the line b - b of (a), also including the interior trim material. Fig. 10 shows still another embodiment of the collision energy absorbing structure of a vehicle body upper portion of an automobile relative to the present invention, in which (a) is a perspective view of the energy absorbing panel and (b) is a sectional view taken along the line b - b of (a), also including the interior trim material. Fig. 11 shows still another embodiment of the collision energy absorbing structure of a vehicle body upper portion of an automobile relative to the present invention, in which (a) is a perspective view of the energy absorbing panel and (b) is a sectional view taken along the line b - b of (a), also including the interior trim material. Fig. 12 is a perspective view showing still another embodiment of the collision energy absorbing structure of a vehicle body upper portion of an automobile relative to the present invention, as viewed in the direction of 12 of Fig. 4. Fig. 13 is a typical or schematic view showing the amount of energy absorption obtained by the collision energy absorbing structure shown in Fig. 12 and the energy absorbing panel with respect to distance. Fig. 14 is a perspective view similar to Fig. 12, showing still another embodiment of the collision energy absorbing structure of a vehicle body upper portion of an automobile relative to the present invention. Fig. 15 is a perspective view similar to Fig. 12, showing still another embodiment of the collision energy absorbing structure of a vehicle body upper portion of an automobile relative to the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to Fig. 1 showing a perspective state and Fig. 2 showing a section, a collision energy absorbing structure absorbs a collision energy in a vehicle body upper portion of an automobile provided with a roofside rail 20 which is a structural member, and comprises an energy absorbing panel 22, an interior trim material 24 and two energy absorbing means 26, 28. The roofside rail 20 is formed as a closed structure by joining respective flanges 29A, 31A and 29B, 31B of an outer panel 30 and an inner panel 32 arranged with a space inward of the outer panel 30 by spot-welding, and extends forward and backward of the vehicle body. The outer panel 30 and the inner panel 32 are made of steel plate. The energy absorbing panel 22 is made of steel plate having a thickness smaller than the thicknesses of the outer panel 30 and the inner panel 32, is disposed in the inward of the inner panel 32 at a distance D (Fig. 1 and Fig. 3), and joined to the roofside rail 20 by spot-welding flanges 23A, 23B to the flange joint portion of the roofside rail 20. As a result, the energy absorbing panel 22 extends by a certain length in the forward and backward direction of the vehicle body while keeping the distance D. The distance D is required for energy absorption and is 10 to 30 mm, and preferably about 20 mm. The vehicle body, as shown in Fig. 4, includes a front pillar 34, a center pillar 36 and a rear pillar 38 respectively connected to the roofside rail 20, while the energy absorbing panel 22 extends from the front pillar 34 to the vicinity of the rear pillar 38 in the illustrated embodiment. The roofside rail 20 further extends rearward. The thickness of the energy absorbing panel 22 is 0.4 to 0.8 mm, preferably about 0.6 mm. On the other hand, the thickness of the outer panel 30 is 0.8 to 1.0 mm, and the thickness of the inner panel 32 is 1.0 to 1.6 mm, preferably about 1.4 mm. The thicknesses of the outer panel and the inner panel may be made either equal or reverse from the above. The roofside garnish 24, which is an interior trim material, is molded from a hard resin such as polypropylene and is arranged at a distance d (Fig. 3) inward of the energy absorbing panel 22. The roofside garnish has energy absorbing means 26 arranged to adjoin each other at a terminal part or portion 40 in the longitudinal extension of the energy absorbing panel 22. The distance d is not required for energy absorption because, as shown in Fig. 2, there is the distance D necessary for energy absorption between the energy absorbing panel 22 and the inner panel 32, and the energy absorbing means 26 occupies a greater distance than the distance D. The energy absorbing means 26 is made of urethane foam in the illustrated embodiment and is adhered to the roofside garnish 24. The rigidity of the terminal portion in the energy absorbing means such as a lattice or urethane foam is substantially the same regardless of the terminal portion or the other portion. However, the farther away from the terminal of the energy absorbing means toward a portion without the energy absorbing means, the less the amount of energy absorption, as shown in Fig. 7(b). Namely, in the range from the terminal E 2 of the energy absorbing means to a distance F where no energy absorbing means exists, the farther the distance F gets, the smaller the amount of energy absorption. Therefore, by selecting the distance F properly, the energy absorbing means 26 can be used as means for compensating a reduction in the amount of energy absorption of the terminal portion 40 of the energy absorbing panel 22. The energy absorbing means 26, in the embodiment shown in Fig. 2, is arranged to adjoin the terminal portion 40 of the energy absorbing panel 22 such that the terminal E 2 of the energy absorbing means 26 is spaced apart from the terminal E 1 of the energy absorbing panel 22 by a distance L 1 . Consequently, a distance L 2 from the terminal portion 40 of the energy absorbing panel 22 to the terminal E 2 of the energy absorbing means 26 is a transitional zone. What trend the amount of energy absorption in this transitional zone has depends on the size of the distance L 1 . For example, in case where the distance L 1 is determined such that the terminal E 1 of the energy absorbing panel 22 comes at the point F in Fig. 7(b), that is, where the amount of energy absorption of the energy absorbing means 26 becomes zero, the amount of energy absorption becomes H as shown in Fig. 7(c) and no compensation occurs. On the other hand, in case where the terminal E 2 of the energy absorbing means 26 and the terminal E 1 of the energy absorbing panel 22 are brought into contact to make the distance L 1 zero, the amount of energy absorption becomes I and the reduced amount of energy absorption of the terminal portion of the energy absorbing panel 22 can be compensated. It is further enabled by the energy absorbing means 28 to compensate the reduced amount of energy absorption in the transitional zone. In the embodiment shown in Fig. 2, the energy absorbing means 28 is a urethane foam disposed substantially over the entire transitional zone and adhered to the inner panel 32. Preferably, the thickness, shape, rigidity and the like of each portion of the energy absorbing means 28 are determined so that, by providing the energy absorbing means 28, the characteristic such as G in Fig. 7(c), that is, the reduction in the amount of energy absorption of the terminal portion 40 of the energy absorbing panel 22 can be completely compensated, and the amount of energy absorption in the transitional zone may present such a characteristic as to be substantially flat. According to this embodiment, since the energy compensating means are formed from the two energy absorbing means 26, 28, the energy absorbing means 28 can be formed without affecting a degree of freedom in designing the interior trim material 24 having the energy absorbing means 26 and the energy absorbing panel 22. Also, selections of material and shape of the energy absorbing means 28 can be relatively easy, and the energy amount corresponding with the reduced amount of energy absorption generated in the transitional zone is easily compensated. As shown in Fig. 3, in the vehicle body upper portion a drip channel 44 is welded to the roofside rail 20, and the roof panel 46 is welded to the drip channel 44. The roofside garnish 24 and a roof liner 48, which are the interior trim material, are stretched across the interior of the vehicle. The door 50, when closed, is brought in tight contact with a weather strip 52 attached to the drip channel 44, and an opening trim 54 attached to the joint portion of the flange. In the following embodiments, the same reference numerals are put when parts of the embodiments shown in Figs. 1 and 2 are substantially the same, and detailed descriptions are omitted. In the embodiment shown in Fig. 5, the energy absorbing panel 62 has a reinforcing structure 64 provided at the terminal portion 63 in its longitudinal direction. Other structures of the energy absorbing panel 62 is substantially the same as the energy absorbing panel 22. As mentioned above, the reduction in the amount of energy absorption of the terminal portion of the energy absorbing panel is attributable to lowering in rigidity of the terminal portion. Therefore, the reinforcing structure 64 is formed at the terminal portion 63, whereby the rigidity of the terminal portion 63 is raised and together with the energy absorbing means 26 compensate the amount of reduction in energy absorption. By varying the irregularity or the sectional shape of the reinforcing structure 64 or bending the reinforcing structure 64, the rigidity can be added and the degree of the rigidity can be changed. In this embodiment, the terminal E 1 of the energy absorbing panel 62 is made as close as possible to the terminal E 2 of the energy absorbing means 26. According to this embodiment, only by reinforcing the terminal portion of the energy absorbing panel, the reduction in energy absorption caused in the transitional zone can be compensated. In the embodiment shown in Fig. 6, a reinforcing structure 70 includes an inclined surface 74 inclined toward the inner panel 32 which the terminal portion 73 of the energy absorbing panel 72 has, and an inclined surface 77 extending along the inclined surface 74 of the energy absorbing panel 72, the inclined surface 77 being provided in an energy absorbing means 76. Other structures of the energy absorbing panel 72 and the energy absorbing means 76 are substantially the same as the energy absorbing panel 22 and the energy absorbing means 26. In this embodiment, the inclined surfaces 74 and 77 are opposed to each other to overlap the energy absorbing panel 72 and the energy absorbing means 76, thereby compensating the reduced amount of energy absorption by a cooperation of both inclined surfaces 74, 77. The amount of energy absorption to be compensated can be adjusted by changing the shape, size or angle of inclination of the portions facing each other of the inclined surfaces 74, 77. In the embodiment shown in Fig. 8, the energy compensating means 80 includes a reinforcing structure 84 provided in the terminal portion 83 in the longitudinal direction of the energy absorbing panel 82, and the energy absorbing means 26. The reinforcing structure 84 is a bead. Namely, the terminal portion 83 is press-molded, so that one side surface is recessed like a groove and the other side surface is expanded outward in a convex shape, thereby enhancing the rigidity. The bead 84 covers the energy absorbing panel 82 except the flanges 86, 87. The bead can be expanded inward, contrary to the illustration. The other constitution of the energy absorbing panel 82 is substantially the same as the energy absorbing panel 22 shown in Figs. 1 and 2. In the embodiment shown in fig. 8, the terminal E 1 of the energy absorbing panel 82 is made as close as possible to the terminal E 2 of the energy absorbing means 26. According to this embodiment, molding for adding the bead to the terminal portion of the energy absorbing panel is easy, and the amount of energy to be compensated can be adjusted by varying the shape, width, depth and the like of the bead. In the embodiment shown in Fig. 9, the energy compensating means 90 includes the reinforcing structure 92 provided at the terminal portion 40 in the longitudinal direction of the energy absorbing panel 22 and the energy absorbing means 26. The reinforcing structure 92 is a thick portion with the terminal portion 40 of the energy absorbing panel 22 thickened by spot-welding a plate material 94 to the terminal 40 of the energy absorbing panel 22. The plate material 94 has a size to cover the energy absorbing panel 22 except the flanges 96, 97. In this embodiment, the terminal E 1 of the energy absorbing panel 22 is made as close as possible to the terminal E 2 of the energy absorbing means 26. According to this embodiment, the reinforcing structure thickened by attaching another plate material to the energy absorbing panel, while the amount of energy to be compensated can be adjusted by varying the material quality, shape, thickness and the like of the another plate material. In the embodiment shown in Fig. 10, the energy compensating means 100 includes a reinforcing structure 104 provided at the terminal 103 in the longitudinal direction of the energy absorbing panel 102 and the energy absorbing means 26. The reinforcing structure 104 is the portion shown by double hatching for convenience' sake in explaining, where the terminal portion 103 is laser-hardened. The hardened portion can be provided over the entire portion of the energy absorbing panel 102, and besides, can be provided on the portion except the flanges 106, 107. In this embodiment, the terminal E 1 of the energy absorbing panel 100 is made as close as possible to the terminal E 2 of the energy absorbing means 26. According to this embodiment, by varying the width, position, conditions and the like of hardening, the amount of energy to be compensated can be adjusted. In the embodiment shown in Fig. 11, the energy compensating means 110 includes a plate metal fixture, i.e., a plate metal bulk 112 provided at the terminal portion 40 in the longitudinal direction of the energy absorbing panel 22, and the energy absorbing means 26. The bulk 112 is formed by bending a steel plate in an approximately S-like shape, and attached to the energy absorbing panel 22 and the inner panel 32 by spot-welding. According to this embodiment, the amount of energy to be compensated can be adjusted by varying the material quality, shape, thickness and the like of the plate metal fixture, i.e., the plate metal bulk. In the above-mentioned embodiments, the energy absorbing means attached to the interior trim material is disposed to adjoin the terminal portion rearward of the energy absorbing panel. Instead of this or together with this, however, it is possible to form such that the energy absorbing means is provided to adjoin the terminal portion forward of the energy absorbing panel, that is, as shown in Fig. 4, the terminal in the joint portion of the roofside rail 20 and the front pillar 34. In the embodiment shown in Fig. 12, the collision energy absorbing structure comprises an energy absorbing panel 122 and an energy absorbing panel 124 as means for compensating the reduced amount of energy absorption of the terminal portion of the energy absorbing panel 122. A roofside rail 126 is formed such that an outer panel 128 and an inner panel 130 arranged at a distance inward of the outer panel 128 are spot-welded at respective flange portions to form a closed structure and extend in the forward and backward direction of the vehicle body. The two energy absorbing panels 122, 124 are 0.6 mm thick steel plate have a thickness smaller than those of the outer panel 128 and the inner panel 130. The two energy absorbing panels 122, 124 have substantially the same sectional shape and thickness as shown in Fig. 12, and have respectively an abdominal portion 123A, 125A arranged at a distance inward of the inner panel 130 and two flange portions 123B, 125B connected to the abdominal portion. The maximum distance among distances from the inner panel 130 is 10 to 30 mm, which is necessary for energy absorption, which is set at 20mm in the illustrated embodiment. The two energy absorbing panels 122, 124 are arranged in the longitudinal direction of the roofside rail 126 so as to overlap the adjacent terminal portions 123C, 125C each other, and without joining the abdominal portion 123A, 125A, namely, with the abdominal portion 123A, 125A kept in the overlapped state, the two energy absorbing panels 122, 124 are joined to the roofside rail 126 by spot-welding 130 respectively the flange portions 123B, 125B to two flange joint portions 127. As a result, the two energy absorbing panels 122, 124 extend in the forward and backward direction of the vehicle body while maintaining the distance from the inner panel 130. As shown in Fig. 4, the energy absorbing panel 122 extends from the front pillar 34 to the rear of the center pillar 36, and the energy absorbing panel 124 extends to the rear pillar 38. The terminal portions of the abdominal portions 123A, 125A of the two energy absorbing panel remain overlapped because, if the terminal portions of the adjacent abdominal portions are fixed by spot-welding or the like, the rigidity of the terminal portions become overly enhanced and exceeds the required amount of energy absorption. According to this embodiment, since the two terminal portions of the energy absorbing panels are overlapped, the amount of energy absorption of the terminal portion of the essential energy absorbing panel can be less reduced, so that the amount of energy absorption can be brought close to the required amount of energy absorption. When the distance L 3 where the terminal portions 123C, 125C of the two energy absorbing panels 122, 124 overlap becomes too great, not only the rigidity of the terminal portion becomes high, but also it causes a waste of material. On the contrary, when the distance L 3 becomes too small, a sufficient energy absorption cannot be attained. As a result of a simulation in which a head form is collided, it turned out that the distance L 3 is preferably 50 - 70 mm, and most preferably L 3 is 60 mm. In this case, as shown in Fig. 13, a portion 134 where the amount of energy absorption lowered is generated between the portion 132 where the terminal portions are overlapped and the portion 133 where the lowering of the amount of energy absorption begins. However, the head form having a predetermined curvature, the existence of the portion 134 where the amount of energy absorption lowered does not matter. According to this embodiment, a wastefulness of lengthening more than necessary the distance where the two energy absorbing panels are overlapped can be eliminated, and the required amount of energy absorption can be substantially ensured. In the embodiment shown in Fig. 14, two energy absorbing panels 142, 144 have an abdominal portion 143A, 145A arranged at a distance inward of the inner panel 130 and two flange portions 143B, 145B connected to the abdominal portion 143A, 145A, respectively. The two energy absorbing panels 142, 144 have substantially the same sectional shape and substantially the same thickness, arranged in the longitudinal direction of the roofside rail 126 such that the terminal portions 143C, 145C adjacent to each other do not overlap, and are joined to the roofside rail 126 respectively by spot-welding the flange portions 143B, 145B to the two flange joint portions 127 of the roofside rail 126. As a result, the two energy absorbing panels 142, 144 extend in the forward and backward direction of the vehicle body while maintaining the distance from the inner panel 130. The abdominal portions 143A, 145A of the two energy absorbing panels 142, 144 are joined at one portion respectively by connecting a tongue 146 projecting rearward from the terminal portion 143C of the abdominal portion 143A of one energy absorbing panel 142 to the terminal portion 145C of the abdominal portion 145A with rivets or by spot-welding 148. In the embodiment shown in Fig. 15, two energy absorbing panels 152, 154 have respectively an abdominal portion 153A, 155A arranged at a distance inward of the inner panel 130, and two flange portions 153B, 155B connected to the abdominal portion. The two energy absorbing panels 152, 154 have substantially the same sectional shape and substantially the same thickness, arranged in the longitudinal direction of the roofside rail 126 such that the terminal portions 153C, 155C adjacent to each other do not overlap, and are joined to the roofside rail 126 by spot-welding the flange portions 153B, 155B to the two flange joint portions 127 of the roofside rail 126. As a result, the two energy absorbing panels 152, 154 extend in the forward and backward direction of the vehicle body while maintaining the distance from the inner panel 130. The abdominal portion 153A, 155A of the two energy absorbing panels 152, 154 are joined at one portion respectively by attaching a plate member 156 crossing both abdominal portions 153A, 155A and respective abdominal portions with a rivet or by spot-welding 158. In the embodiments shown in Figs. 14 and 15, to compensate the reduction in the amount of energy absorption of the terminal portion of the essential energy absorbing panel, only a part of the terminal portions of the adjoining abdominal portions is joined by using the tongue 146 or the plate member 156. By fully joining the terminal portions of the adjoining abdominal portions like the above- mentioned overlapping, the rigidity of the joint portion becomes too great. However, by joining a part of the terminals of the adjoining abdominal portions, the rigidity of the terminal portions can be maintained properly, so that the reduction in the amount of energy absorption of the essential energy absorbing panel can be compensated. From this point of view, the thickness of the tongue 146 is set to be the same as the thickness of the energy absorbing panel 142, the thickness of the plate member 156 is set to be the same as the thickness of the energy absorbing panel 152, and further, the strength of the rivet or the spot-welding 148, 158 is set to be sheared by an energy not exceeding the required amount of energy absorption. The collision energy absorbing structure of a vehicle body upper portion of an automobile shown in Figs. 12 through 15, has the following functions. When a collision force acts from the inside to outside of a passenger compartment, the essential metal energy absorbing panel is elastically deformed to absorb the collision energy. In the embodiment in Fig. 12, when a collision force acts on a portion where the terminal portions 123C, 125C of the two energy absorbing panels 122, 124 are overlapped, the terminal portions are mutually displaced to be plastically deformed while generating a frictional force. Due to this frictional force and plastic deformation, the collision energy is absorbed. Also, in the embodiments shown in Figs. 14 and 15, when a collision force acts on the terminal portions of the two energy absorbing panels 142, 144, 152, 154, since the respective abdominal portions of the adjoining terminal portions are joined at a part, the terminal portions are plastically deformed, pulling each other at the joint portion, while being plastically deformed at the other portions. Thereby, the collision energy is absorbed.

Claims: A collision energy absorbing structure of a vehicle body upper portion of an automobile having a structural member (20, 126) extending in the longitudinal direction and formed to have a closed structure with an outer panel (30, 128) and an inner panel (32, 130) joined at their respective flange portions, the inner panel (32, 130) being disposed with a first space inward of the outer panel (30, 128), and a resin interior trim material (24) disposed with a second space inward of the inner panel (32, 130), comprising: a metal energy absorbing panel (22, 62, 72, 82, 102, 122) having a thickness smaller than the thicknesses of the outer panel (30, 128) and the inner panel (32, 130), said metal energy absorbing panel (22, 62, 72, 82, 102, 122) being disposed in said second space with a third space (D) inward of said inner panel (32, 130), extending in the longitudinal direction by a predetermined length, and joined to the flange portions of said structural member (20, 126) ; characterized by energy compensating means (28, 64, 74, 76, 77, 84, 92, 104, 110, 124, 144, 146, 154, 156) disposed in said second space at an end portion of the metal energy absorbing panel (22, 62, 72, 82, 102, 122) for compensating a reduced amount of energy absorption of at least one terminal portion (40, 63, 73, 83, 103, 123A, 143A, 153A) in the longitudinal direction of said energy absorbing panel. A collision energy absorbing structure of a vehicle body upper portion of an automobile according to claim 1, wherein said energy compensating means includes energy absorbing means (26, 76) provided in said interior trim material (24) on the extension in the longitudinal direction of said energy absorbing panel (22, 72). A collision energy absorbing structure of a vehicle body upper portion of an automobile according to claim 2, wherein said energy compensating means further includes second energy absorbing means (28) formed separately from said energy absorbing panel (22) and said energy absorbing means (26) and disposed so as to adjoin said terminal portion (40) of said energy absorbing panel (22) and said energy absorbing means (26). A collision energy absorbing structure of a vehicle body upper portion of an automobile according to claim 3, wherein said energy absorbing means (26) and said second energy absorbing means (28) are made of resin such as lattice or urethane foam. A collision energy absorbing structure of a vehicle body upper portion of an automobile according to claim 2, wherein said energy absorbing means (26) is disposed to adjoin said terminal portion (40, 63, 83, 103) of said energy absorbing panel (22, 62, 82, 102), and wherein said energy compensating means further includes a reinforcing structure (64, 84, 92, 104) provided at said terminal portion (40, 63, 83, 103) of said energy absorbing panel (22, 62, 82, 102). A collision energy absorbing structure of a vehicle body upper portion of an automobile according to claim 5, wherein said reinforcing structure (64, 84) is formed from a bead either projecting outward or inward from said terminal portion of said energy absorbing panel. A collision energy absorbing structure of a vehicle body upper portion of an automobile according to claim 5, wherein said reinforcing structure (92) is formed as a thick portion with a thickness greater than the thickness of said energy absorbing panel (22). A collision energy absorbing structure of a vehicle body upper portion of an automobile according to claim 5, wherein said reinforcing structure (104) is formed from a hardened portion. A collision energy absorbing structure of a vehicle body upper portion of an automobile according to claim 2, wherein said energy compensating means includes an inclined surface (74) provided at said terminal portion (73) of said energy absorbing panel (72) and inclined toward said inner panel (32), and an inclined surface (77) provided at said energy absorbing means (76) and extending along said inclined surface (74) of said energy absorbing panel (72). A collision energy absorbing structure of a vehicle body upper portion of an automobile according to claim 2, wherein said energy compensating means (110) further includes a plate metal fixture (112) formed separately from said energy absorbing panel (22) and said energy absorbing means (26) and joined to said terminal portion (40) of said energy absorbing panel (22) and to said inner panel (32). A collision energy absorbing structure of a vehicle body upper portion of an automobile according to claim 1, wherein said energy compensating means includes second energy compensating means (123C, 125C, 146, 156) and a metal second energy absorbing panel (124, 144, 154) having substantially the same sectional shape and substantially the same thickness as said energy absorbing panel (122, 142, 152), said second energy absorbing panel (124, 144, 154) being disposed in the longitudinal direction of said energy absorbing panel (122, 142, 152) through said second energy compensating means (123C, 125C, 146, 156), which also compensates a reduced amount of energy absorption of a terminal portion (125C, 145C, 155C) of said second energy absorbing panel (124, 144, 154). A collision energy absorbing structure of a vehicle body upper portion of an automobile according to claim 11, wherein each of said two energy absorbing panels (122, 124) has an abdominal portion (123A, 125A) disposed with said third space from said inner panel (130) and flange portions (123B, 125B) connected to said abdominal portion (123A, 125A), and wherein said second energy compensating means is formed by means of a structure without joining said abdominal portions (123A, 125A) and with said terminal portion (125C) of said second energy absorbing panel (124) overlapped on said terminal portion (123C) of said energy absorbing panel (122). A collision energy absorbing structure of a vehicle body upper portion of an automobile according to claim 12, wherein said overlapped length in the longitudinal direction of said terminal portions (123C, 125C) of said two energy absorbing panels (122, 124) is in the range of 50 to 70 mm. A collision energy absorbing structure of a vehicle body upper portion of an automobile according to claim 11, wherein each of said two energy absorbing panels (142, 144, 152, 154) has an abdominal portion (143A, 145A, 153A, 155A) disposed with said third space from said inner panel (130) and flange portions (143B, 145B, 153B, 155B) connected to said abdominal portion (143A, 145A, 153A, 155A), and wherein said second energy compensating means is formed such that said second energy absorbing panel (144, 154) is disposed to adjoin said energy absorbing panel (142, 152) so that said terminal portion (145C, 155C) of said second energy absorbing panel (144, 154) does not overlap said terminal portion (143C, 153C) of said energy absorbing panel (142, 152), and said second energy absorbing panel (144, 154) is joined with said energy absorbing panel (142, 152) at only a part of respective abdominal portions (143A, 145A, 153A, 155A) of said two energy absorbing panels (142, 144, 152, 154). A collision energy absorbing structure of a vehicle body upper portion of an automobile according to claim 14, wherein one (142) of said energy absorbing panels is provided with a tongue (146) extending toward the other (144) and said two energy absorbing panels (142, 144) are joined through the tongue (146) and fastening means (148). A collision energy absorbing structure of a vehicle body upper portion of an automobile according to claim 14, wherein said second energy compensating means further includes a plate member (156) and said two energy absorbing panels (152, 154) are joined through the plate member (156) and fastening means (158). A collision energy absorbing structure of a vehicle body upper portion of an automobile according to claim 1, wherein said third space (D) is in the range of 10 to 30 mm.

Inventors: GONDO KENJI, KATO HISATAKA, MATSUYAMA NARIHIDE, SHIKIMACHI KAZUTOMO, SUGAMOTO TATSUYA, GONDO, KENJI, KATO, HISATAKA, MATSUYAMA, NARIHIDE, SHIKIMACHI, KAZUTOMO, SUGAMOTO, TATSUYA
Applicants: TOYOTA MOTOR CO LTD, TOYOTA JIDOSHA KABUSHIKI KAISHA
Application year: 1996
Main classification: B62D25
IPC codes: B60R21