Land vehicles: bodies and tops – Bodies – Body shell
Reexamination Certificate
1999-04-19
2001-03-13
Pape, Joseph D. (Department: 3612)
Land vehicles: bodies and tops
Bodies
Body shell
C138S121000, C280S751000, C188S371000
Reexamination Certificate
active
06199941
ABSTRACT:
INCORPORATION BY REFERENCE
The disclosures of Japanese Patent Application Nos. HEI 10-150063 filed on May 29, 1998, HEI 10-126501 filed on May 8, 1998 and HEI 10-247170 filed on Sep. 1, 1998, including the specifications, drawings and abstracts are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an impact energy absorbing structure formed in an upper portion of a body of a motor vehicle and an impact energy absorbing member. More particularly, the invention relates to a structure and a member for absorbing impact energy in an upper vehicle body portion including a vehicle body structural member, such as a pillar, a roof side rail, a header or the like, and an interior trim, such as a pillar garnish, a roof lining or the like, that is spaced from the structural member by an interval extending toward the interior of a passenger compartment, and an energy absorbing member disposed within the interval.
2. Description of the Related Art
In motor vehicles, particularly passenger cars, an energy absorbing member is disposed in an interval space between an interior trim and a structural member of a vehicle body. Therefore, if an impact load is applied in a direction from the interior trim to the structural member, the energy absorbing member deforms to absorb energy of the impact load. Normally employed energy absorbing members are, for example, a grid rib member, a urethane pad, a steel member formed by bending a thin steel sheet so as to have a hat-like sectional shape, and the like. Also employed as an energy absorbing member is a generally-termed hybrid pipe (as described in U.S. Pat. No. 5,680,886) that is made up of a metal foil core member and sheets of a material other than metal that are laid on opposite side surfaces of the core member. In the hybrid pipe, the core member and the sheets on the opposite side surfaces of the core member are corrugated so that ridges (protruded portions) and grooves (recessed portions) alternate in a direction of an axis of the pipe.
The hybrid pipe, being hollow, has various excellent properties as an energy absorbing member. That is, the hollow hybrid pipe is light-weight, and easy to shape into a desired sectional shape. Furthermore, it is possible to adjust the load-displacement energy absorbing characteristic of a hybrid pipe by changing the pitch between adjacent protruded portions (recessed portions).
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an impact energy absorbing structure and an impact energy absorbing member that further improve the energy absorbing characteristics of a hybrid pipe.
The structure of the invention absorbs impact energy in an upper vehicle body portion including a vehicle body structure member, an interior trim spaced from the structure member by an interval extending inward from the structure member, and an energy absorbing member disposed in the interval.
In accordance with a first aspect of the invention, the energy absorbing member is a hybrid pipe having a metal foil core member and sheets laminated on opposite surfaces of the core member, each sheet being formed from a material other than metal. The core member and the sheets on the opposite surfaces of the core member are shaped so that the hybrid pipe has protruded portions and recessed portions that are contiguous in a direction of an axis of the hybrid pipe. At least one of an outer peripheral surface of the hybrid pipe and an inner peripheral surface of the hybrid pipe is at least partially coated with an adhesive coating material.
The hybrid pipe has the property of elongating in the direction of the axis thereof and reducing in the apparent plate thickness thereof when the hybrid pipe is compressed in a direction intersecting the axis. However, in the portion of the outer and/or inner peripheral surfaces of the hybrid pipe coated with the adhesive coating material, the resistance against the axial elongation of the hybrid pipe caused by compression is increased, so that the apparent plate thickness in the coated portion remains substantially the same as the original apparent plate thickness after the hybrid pipe is compressed. Furthermore, the duration during which the apparent plate thickness of the hybrid pipe is maintained if an impact load occurs on the hybrid pipe in a direction intersecting the axis of the hybrid pipe is relatively long. Therefore, energy absorbing characteristics with a sharp rising of load can be achieved.
Since the hybrid pipe retains substantially constant apparent plate thickness if compressed in directions intersecting the axis of the hybrid pipe, the hybrid pipe achieves energy absorbing characteristics with a sharp rising of load. Therefore, the impact energy absorbing structure can be locally optimized without a need to change the material or sectional shape of the hybrid pipe. Furthermore, the hybrid pipe is easy to bend, so that the hybrid pipe can easily be disposed so as to substantially conform to the shape of the structure member or the interior trim.
In accordance with a second aspect of the invention, the energy absorbing member is a hybrid pipe having a metal foil core member and sheets laminated on opposite surfaces of the core member, each sheet being formed from a material other than metal, and the core member and the sheets on the opposite surfaces of the core member are shaped so that the hybrid pipe has protruded portions and recessed portions that are contiguous in a direction of an axis of the hybrid pipe. At least one of an outer peripheral surface of the hybrid pipe and an inner peripheral surface of the hybrid pipe is partially coated with an adhesive coating material in accordance with a predetermined energy absorbing characteristic.
The energy absorbing characteristics of the hybrid pipe can be adjusted locally or entirely depending on whether the coating material is provided. The hybrid pipe may possibly receive moisture due to condensation, for example, if the hybrid pipe is disposed between a pillar and a pillar garnish or between a roof side rail and a roof lining. If the hybrid pipe is made up of a metal foil core member and sheets made of paper, a paper sheet of the hybrid pipe swells upon deposition of condensed water. It has been found that repeated cycles of swelling and drying of the paper sheet of a hybrid pipe reduces the proof stress of the hybrid pipe by about 5-10%. Such a proof stress reduction can be prevented by the coating material. If moisture occurring in a recessed portion of the hybrid pipe freezes in cold weather, the volume expansion involved in water freezing forces the hybrid pipe to elongate in the direction of the axis, so that the apparent plate thickness of the hybrid pipe reduces, resulting in energy absorbing characteristics with a gentle rising of load. Occurrence of such energy absorbing characteristics with a gentle rising of load can be prevented by the coating material. A coating material layer provided for this purpose may be thin, unlike a coating material layer provided for achieving energy absorbing characteristics with a sharp rising of load.
In the first and second aspects of the invention, a layer thickness of the coating material is partially varied in accordance with a predetermined energy absorbing characteristic.
By increasing the layer thickness of the coating material, energy absorbing characteristics with a sharper rising of load can be achieved. Therefore, by selecting a layer thickness of the coating material for each site so as to achieve predetermined energy absorbing characteristics, optimal energy absorbing characteristics can be achieved in accordance with individual sites where energy is to be absorbed.
The core member may be formed from one of an aluminum foil, a stainless steel foil and a magnesium alloy foil, and the sheets may be formed from paper. The coating material may be made of a resin selected from a group at least consisting of acrylic resins and epoxy resins, and the coating material may be
Kato Katsumi
Takahara Isamu
Oliff&Berridge, PLC
Pape Joseph D.
Toyota Jidosha & Kabushiki Kaisha
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