U.S. patent application number 11/220675 was filed with the patent office on 2006-04-20 for floor sheet assembly.
This patent application is currently assigned to HONDA MOTOR CO. LTD. Invention is credited to Kazutaka Ano, Kaoru Aoyagi, Naoto Ishii, Mitsuhiro Nishizaka, Yasuyuki Tamane.
Application Number | 20060080941 11/220675 |
Document ID | / |
Family ID | 36179282 |
Filed Date | 2006-04-20 |
United States Patent
Application |
20060080941 |
Kind Code |
A1 |
Ishii; Naoto ; et
al. |
April 20, 2006 |
Floor sheet assembly
Abstract
A floor sheet assembly has an intermediate member and a pair of
sheet members. The intermediate member includes at least a thin
panel, on which a plurality of hollow projections is formed. The
pair of sheet members sandwiches the intermediate member. The
intermediate member and the pair of sheet members form a honeycomb
structure.
Inventors: |
Ishii; Naoto; (Saitama,
JP) ; Tamane; Yasuyuki; (Saitama, JP) ;
Nishizaka; Mitsuhiro; (Saitama, JP) ; Aoyagi;
Kaoru; (Saitama, JP) ; Ano; Kazutaka;
(Saitama, JP) |
Correspondence
Address: |
ARENT FOX PLLC
1050 CONNECTICUT AVENUE, N.W.
SUITE 400
WASHINGTON
DC
20036
US
|
Assignee: |
HONDA MOTOR CO. LTD
|
Family ID: |
36179282 |
Appl. No.: |
11/220675 |
Filed: |
September 8, 2005 |
Current U.S.
Class: |
52/782.1 |
Current CPC
Class: |
E04C 2/3405 20130101;
E04C 2002/3427 20130101 |
Class at
Publication: |
052/782.1 |
International
Class: |
E04C 2/00 20060101
E04C002/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 1, 2004 |
JP |
2004-289818 |
Claims
1. A floor sheet assembly comprising: an intermediate member
including at least a thin panel, on which a plurality of hollow
projections is formed; and a pair of sheet members sandwiching the
intermediate member; wherein the intermediate member and the pair
of sheet members form a honeycomb structure.
2. A floor sheet assembly according to claim 1, wherein the
intermediate member has a plurality of thin panels and a plurality
of hollow projections formed on one thin panel abuts a plurality of
hollow projections formed on another thin panel.
3. A floor sheet assembly according to claim 1, wherein holes,
which provide fluid communication with outside air to space within
the honeycomb structure, are bored at least on one side of the
floor sheet assembly.
4. A floor sheet assembly according to claim 3, further comprising
a surface member: wherein holes are bored in the surface member
which is attached to a sheet member, and the holes are aligned with
the holes which are bored in the sheet member, and wherein the
surface member is made of one of wood and plastic.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a floor sheet assembly,
which is attached to a floor of a vehicle or house.
[0002] A floor sheet used for a room of a house is known, which
employs flooring that is decorated with grain and bonded to a sheet
of plywood (See patent document 1, for example). Because such a
floor sheet not only is more elaborately designed than a carpet
used for a vehicle but also has a characteristic of washability, it
has been expected that such a floor sheet will be applied to a
vehicle, a minivan, for example.
Patent document 1: Japanese Published Patent Application
11-62197
[0003] However, it has not been appropriate that the floor of a
vehicle should be covered with a conventional floor sheet without
modification, which is developed for application to a house. This
is attributed to the fact that this conventional floor sheet is
adapted to be relatively thick so as to increase its sound
absorption and stiffness, which leads to an increase in a gross
weight of the vehicle.
SUMMARY OF THE INVENTION
[0004] The present invention seeks to provide a floor sheet
assembly which is able not only to restrain an increase in a gross
weight of a vehicle, but also to increase sound absorption as well
as stiffness of the vehicle.
[0005] It is an aspect of the present invention to provide a floor
sheet assembly, which comprises an intermediate member and a pair
of sheet members. The intermediate member includes at least a thin
panel, on which a plurality of hollow projections is formed. The
pair of sheet members sandwiches the intermediate member. The
intermediate member and the pair of sheet members form a honeycomb
structure.
[0006] The invention described above, which introduces the
honeycomb structure that has a plurality of spaces defined by the
intermediate member and the pair of sheet members, excels in its
light weight and high stiffness. If the floor sheet assembly
according to the invention is applied to a floor of a vehicle, for
example, it is possible not only to restrain an increase in a gross
weight of the vehicle but also to increase sound absorption and
stiffness of the floor.
[0007] It is another aspect of the present invention to provide a
floor sheet assembly, in which an intermediate member has a
plurality of thin panels and a plurality of hollow projections
formed on one thin panel abuts a plurality of hollow projections
formed on another thin panel.
[0008] The invention described above, which provides a larger space
within the intermediate member without increasing a height of the
projections, is able to increase not only stiffness but also
impulse absorption and sound absorption of the floor sheet
assembly.
[0009] It is still another aspect of the present invention to
provide a floor sheet assembly, in which holes providing fluid
communication with outside air to space within a honeycomb
structure are bored at least on one side of the floor sheet
assembly.
[0010] The holes described above are bored in the following manner.
The holes are bored in both sheet member and solid portion of a
thin panel at overlapping locations. In contrast, the holes are
bored only in the sheet member at locations where the sheet member
confronts hollow projections of the thin panel, which appear to be
concave as seen from the sheet member.
[0011] Because the holes are bored at least on one side of the
floor sheet assembly according to the invention described above, it
is possible to guide noise reaching the sheet member, which lies on
the same side, into a honeycomb structure so that the noise is
efficiently absorbed, even if the sheet member does not
breathe.
[0012] It is yet another aspect of the present invention to provide
a floor sheet assembly, which further comprises a surface member.
Holes are bored in the surface member which is attached to a sheet
member. And the holes are aligned with the holes which are bored in
the sheet member. The surface member is made of one of wood and
plastic.
[0013] According to the invention described above, the surface
member which usually does not breathe has the holes, which are
aligned with the holes bored in the sheet member. As a result, it
is possible for the floor sheet assembly not only to have a
honeycomb structure efficiently absorb noise generated in a cabin,
but also to satisfy an owner of a vehicle by providing free
selection of a favorite surface material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a perspective view illustrating a vehicle, to
which a floor sheet assembly according to the present invention is
applied.
[0015] FIG. 2 is an exploded perspective view showing in detail a
floor sheet assembly illustrated in FIG. 1.
[0016] FIG. 3A is a perspective view showing a floor sheet assembly
in FIG. 2 in a piled configuration. FIG. 3B is a sectional view
taken along line A-A of FIG. 3A.
[0017] FIG. 4 is a graph showing sound absorption of a floor sheet
assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] An embodiment of the present invention is now described with
reference to drawings.
[0019] As shown in FIG. 1, a floor sheet assembly 1 is applied to a
vehicle C as flooring. The floor sheet assembly 1 includes, as
shown in FIG. 2, an intermediate member 10 and a pair of sheet
members 20 which sandwiches the intermediate member 10. Of the pair
of sheet members 20, flooring (a surface member) 30 is bonded to an
upper sheet member 20, and an insulator 40 is bonded to a lower
sheet member 20. The intermediate member 10 and the pair of sheet
members 20 together form a honeycomb structure 2.
[0020] As shown in FIG. 2, the intermediate member 10 includes two
sheets of thin panels 11 and 12, which are geometrically arranged
to be in upper and lower positions, respectively. Hollow
projections 13 and 14 are formed on the thin panels 11 and 12,
respectively. The projections 13 are arranged so that between any
neighboring lines of the projections 13, a projection 13 in one
line is located in between two projections 13 in the other line
with respect to a linear direction. So are the projections 14. An
end portion of a projection 13 abuts an end portion of a projection
14, and these portions are fixed to each other (See FIGS. 3A and
3B). First holes H1 for absorbing sound are bored in a flat portion
11a of the upper thin panel 11 in a vertical direction, where no
projections 13 are formed. Furthermore, the first holes H1 are
bored in the thin panel 11 at intervals .alpha. in a linear
direction, in which the projections 13 are arranged in a line. When
arrangement of the first holes H1 is viewed in the other direction
perpendicular to the one described above, they are bored at
intervals .beta..
[0021] The sheet member 20 is a member configured like a sheet
which does not breathe. Two sheet members 20 are fixed to upper and
lower surfaces of the intermediate member 10 described above,
respectively. Of these two sheet members 20, second holes H2 for
absorbing sound, which have the same shape and interval as the
first holes H1 described above, are bored in the upper sheet member
20. The second holes H2 are adapted to be aligned with the first
holes H1.
[0022] It is, preferably but not necessarily, recommended that
polypropylene (PP) should be adopted for the sheet member 20 and
the intermediate member 10. However, the present invention does not
limit material selection, and it may be alternatively possible to
adopt engineering plastics and other olefinic plastics than
polypropylene. As examples for these other olefinic plastics,
polyethylene and a mixture of polypropylene and rubber composition
(TPO) may be listed. As engineering plastics, polycarbonate,
polyamide, modified polyphenyleneether, polyethylene terephthalate,
polybutylene terephthalate, polyacetal and polyphenylene sulfide
may be listed. In this connection, it may be possible to adopt
methods for manufacturing a honeycomb structure 2 such as a method
using a vacuum molding device and a method with injection molding,
which the inventor disclosed in Japanese Published Patent
Application 2000-326430.
[0023] The flooring 30, whose surface 30a is decorated with a
pattern such as grain and which does not breathe, is fixed to the
upper sheet member 20. Third holes H3, which have the same shape
and interval as the second holes H2, are bored in the flooring 30
so that the third holes H3 are aligned with the second holes
H2.
[0024] The holes H1, H2 and H3, which are together referred to as
holes H hereinafter, are preferably but not necessarily bored
simultaneously from outside to the space within the honeycomb
structure 2 after the intermediate member 10, the sheet member 20
and the flooring 30 are placed one upon another and fixed each
other. It may be possible to arbitrarily select an appropriate size
and number of the holes H, taking into account a level and
frequency of noise to be absorbed.
[0025] The insulator 40, which is made of a sound absorbing
material, principally absorbs noise (road noise) coming from a side
closer to a road surface.
[0026] Description is given of mechanism for sound absorption
carried out by the floor sheet assembly 1 according to the present
embodiment.
[0027] As shown in FIG. 3B, when a sound is created in a cabin, it
enters the space within the intermediate member 10 through a hole
H. This space is defined by flat portions 11a and 12a of the thin
panels 11 and 12 and externally circumferential surfaces of the
projections 13 and 14. When the sound entering the space is
repeatedly reflected by the projections 13 and 14, a level of the
sound gradually decreases as a result of transformation of energy
in the form of vibration which the sound induces on the projections
13 and 14. In this way, the sound is ultimately absorbed by the
intermediate member 10.
[0028] As described above, the present embodiment brings about the
following advantages.
[0029] Because the holes H are bored in the thin panel 11, sheet
member 20 and flooring 30, each of which does not breathe, it is
possible not only to efficiently absorb noise in the cabin, but
also to provide free selection of flooring 30 according to a taste
of an owner of a vehicle, which makes the owner feel more
satisfied.
[0030] Furthermore, because the honeycomb structure 2, which is
characterized by high stiffness, sound absorption and light weight,
is introduced as a member of the floor sheet assembly 1, a heavy
sound insulating material, which has been conventionally attached
to the floor of a vehicle, can be removed. As a result, it is
possible to contribute to a decrease in a gross weight of a
vehicle.
[0031] In addition, the honeycomb structure 2, which has internally
complex structure, can provide fire resistance to the floor sheet
assembly 1.
[0032] It will now be appreciated from the foregoing description
that the present invention is not limited to the particularly
illustrated embodiment discussed above and may be carried out in
various modified forms.
[0033] In the embodiment described above, the floor sheet assembly
1 is applied to the floor of the vehicle. However, the invention is
not limited to this application and it is possible to apply the
floor sheet assembly 1 to a house. In addition, it may be possible
to select steel, for example, instead of plastic for the
intermediate member 10 and the sheet member 20.
[0034] The invention is not limited to the embodiment described
above, which has the holes H that are bored in the upper thin panel
11, upper sheet member 20 and flooring 30. For example, when holes
are bored to provide fluid communication between outside air and a
space, which is defined by a hollow projection 13 and a sheet
member 20, it may be possible to bore the holes only in the sheet
member 20 and flooring 30. In addition, it is not mandatory that
the holes are perpendicularly bored in the thin panel 11, upper
sheet member 20 and flooring 30 as described in the embodiment
described above. For example, it may be possible to bore the holes
diagonally with respect to these components.
EXAMPLE
[0035] Description is given of an example (test results) of sound
absorption obtained by the floor sheet assembly 1 according to the
embodiment described above. Conditions under which testing was
carried out are as follows:
(1) material for an intermediate member 10 and sheet member 20:
polypropylene (PP)
(2) material for an insulator 40: urethane
(3) diameter of a hole H: 2 mm
(4) interval a of holes H: 40 mm
(5) interval .beta. of holes H: 30 mm
(6) height of projections 13 and 14: 5.5 mm
(7) diameter of end portion of projections 13 and 14: 2 mm
(8) diameter of base portion (opening) of projections 13 and 14: 7
mm
(9) interval of projections 13 and 14: 11 mm
(10) thickness of thin panels 11 and 12: 0.5 mm
(11) thickness of a sheet member 20: 5.5 mm
(12) thickness of flooring 30: 2 mm
(13) thickness of an insulator 40: 20 mm
[0036] Description is given of sound absorption by the floor sheet
assembly 1, which satisfies the conditions described above, with
reference to FIG. 4.
[0037] As shown in FIG. 4, it is demonstrated that the floor sheet
assembly 1 (with holes H) achieves better performance in terms of
sound absorption when a frequency of a sound approximately falls in
a range of 800 to 4000 Hz, in comparison with a floor sheet
assembly, which has the same setup as the floor assembly 1 except
for the holes H. It is noted that the floor sheet assembly 1
increases sound absorption by 20% for a sound with a range of 1000
to 2000 Hz in comparison with the floor sheet assembly without the
holes H. In this connection, the performance in terms of sound
absorption is meant to represent a rate, which is obtained by a
division, a dividend of absorbed sound energy and a divisor of
generated sound energy.
[0038] It is concluded that the embodiment described above, which
has the holes H bored in the floor sheet assembly 1, is able to
efficiently absorb sound having a certain range of frequency.
[0039] Foreign priority document, JP 2004-289818 filed on Oct. 1,
2004, is hereby incorporated by reference.
* * * * *