U.S. patent application number 12/028549 was filed with the patent office on 2009-02-19 for wooden building member.
Invention is credited to Hiroyuki Adachi, Kazuyoshi KIMURA.
Application Number | 20090044486 12/028549 |
Document ID | / |
Family ID | 37727379 |
Filed Date | 2009-02-19 |
United States Patent
Application |
20090044486 |
Kind Code |
A1 |
KIMURA; Kazuyoshi ; et
al. |
February 19, 2009 |
WOODEN BUILDING MEMBER
Abstract
A wooden building member includes an elongated structural
portion having a rectangular cross section and capable of receiving
load applied thereto, a coating portion coating an entire length of
at least three sides of the cross section of the structural
portion, and an insulating portion interposed therebetween in a
laminated manner and prevents load from transmitting to the coating
portion. Since load is received by the structural portion,
structural strength designing is facilitated, and even if the
coating portion is completely burned down, the structural portion
coated with the insulating portion is not easily burned down. Thus,
fireproof capability of the wooden building member can be improved.
Further, since a surface of the wooden building member is coated
with the coating portion, the insulating portion is not exposed to
the exterior thereby improving its appearance.
Inventors: |
KIMURA; Kazuyoshi;
(Yamagata, JP) ; Adachi; Hiroyuki; (Yamagata,
JP) |
Correspondence
Address: |
FINNEGAN, HENDERSON, FARABOW, GARRETT & DUNNER;LLP
901 NEW YORK AVENUE, NW
WASHINGTON
DC
20001-4413
US
|
Family ID: |
37727379 |
Appl. No.: |
12/028549 |
Filed: |
February 8, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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PCT/JP2006/315625 |
Aug 8, 2006 |
|
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12028549 |
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Current U.S.
Class: |
52/831 |
Current CPC
Class: |
E04C 3/14 20130101; E04C
3/29 20130101; E04C 3/36 20130101; E04B 1/943 20130101; E04C 3/122
20130101 |
Class at
Publication: |
52/831 |
International
Class: |
E04C 3/12 20060101
E04C003/12 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 9, 2005 |
JP |
2005-230312 |
Claims
1. A wooden building member comprising: An elongated structural
portion having a rectangular cross-section, and configured to
receive a load applied thereto; a coating portion with which at
least three sides of the cross section of the structural portion
are coated over an entire length of the structural portion; and an
insulating portion which is interposed between the structural
portion and the coating portion in a laminated manner and prevents
the load applied to the structural portion from transmitting to the
coating portion.
2. The wooden building member according to claim 1, wherein the
insulating portion comprises a noncombustible material or an
incombustible material.
3. The wooden building member according to claim 2, wherein an
aluminum foil is stuck to at least a joint appearing in an outer
peripheral surface of the noncombustible material or the
incombustible material.
4. The wooden building member according to claim 1, wherein at
least one of the structural portion and the coating portion
comprises a noncombustible liquid-impregnated building
material.
5. The wooden building member according to claim 1, wherein the
coating portion has a thickness thereof that is set according to a
carbonizing speed of its base material thereby allowing the coat
portion not to be burned down in at least an hour.
6. The wooden building member according to claim 1, wherein the
coating portion is constituted in such a manner that laminar
materials, each having a rectangular cross section are arranged so
that one side of the cross section of the laminar material extends
approximately perpendicularly to respective sides defining a cross
section of the structural portion and their extended lines.
7. The wooden building member according to claim 6, wherein the
laminar materials are arranged so that edge grain of each of the
laminar materials appears as much as possible on an outer
peripheral surface of the coating portion.
Description
[0001] This application is a continuation of PCT/JP2006/315626,
filed on Aug. 8, 2006.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an architectural technique
for facilitating designing of a structural strength and for
improving a fireproof capability while ensuring an attractive
exterior appearance in wooden building members such as posts and
beams which structure frameworks of a wooden building or
architecture.
[0004] 2. Description of the Related Art
[0005] As disclosed in Japanese Laid-open (Kokai) Patent
Application Publication No. H08-151683, frameworks of wooden
buildings or architectures are structured by suitably jointing
wooden building members, such as posts and beams. The posts and the
beams of the wooden building members are such important members
that receive various loads, such as own weight of a building, and
external forces applied due to deposited snow, wind and earthquake.
In recent years, in addition to conventionally used solid
materials, laminated lumbers which are obtained by laminating, in
parallel, laminar materials (lumbers) having, by severing, a
predetermined dimension, respectively, and bonding them with
synthetic resin adhesive so as to be formed in one integral part,
have been widely used in order to achieve non-defective and uniform
wooden building members having high physical strength.
[0006] When a fire breaks out in a wooden building, if important
members such as posts and beams are burned down before the fire is
extinguished, the building might collapse. At this process, the
posts, the beams and the like are exposed to the blaze and
carbonization from their surfaces to their insides progresses
gradually. Structural resistances of the important members of the
wooden building should be designed to secure the time from the fire
breaking to evacuation, but since a rectangular cross section of
the members which receives loads is gradually reduced by the
carbonization, the time up to the collapse of the building is
uncertain. Whereas the wooden building members are suitable for
Japanese climates, their fireproof capability is inferior to that
of armored or reinforced concrete and bricks.
SUMMARY OF THE INVENTION
[0007] Therefore, in view of such a conventional problem, it is an
object of the present invention to provide a wooden building member
in which a structural portion which receives a load applied thereto
and a coating portion which coats the structural portion are
arranged to be separated by interposing therebetween a layered
insulating portion which prevents the load applied to the
structural portion from being transmitted to the coating portion,
so that designing of a structural strength is facilitated and
fireproof capability is improved while ensuring an attractive
exterior appearance.
[0008] Therefore, a wooden building member according to the present
invention includes: an elongated structural portion having a
rectangular cross-section, and configured to receive a load applied
thereto; a coating portion with which at least three sides of the
cross section of the structural portion are coated over an entire
length of the structural portion; and an insulating portion which
is interposed between the structural portion and the coating
portion in a laminated manner and prevents the load applied to the
structural portion from being transmitted to the coating
portion.
[0009] According to the present invention, when a fire breaks out
in a wooden building and the fire spreads from outsides of wooden
building members, a coating portion is exposed to blaze, and
carbonization gradually progresses from its outer periphery to its
inward portion. When the entire coating portion is burned down for
a certain time, an insulating portion in the inward portion
appears. Since a structural portion is covered with the insulating
portion, the structural portion is not exposed directly to blaze
and the carbonization progresses very slowly, and thus the
structural portion is not burned down in a short time. On the other
hand, since the surfaces of the wooden building members are coated
with the coating portion, the insulating portion is not exposed to
the outside, and its exterior appearance can be ensured. For this
reason, while the appearance of the wooden building members is
improved, the fireproof capability can be improved. Since various
loads applied to the wooden building are received mainly by the
structural portion, the designing of the structural strength is
facilitated while the fireproof capability is ensured, and further,
even if the coating portion is completely burned down, the building
does not collapse.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a perspective view illustrating a post as a wooden
building member according to the present invention;
[0011] FIG. 2 is a cross-sectional view of the post of the present
invention, as illustrated in FIG. 1;
[0012] FIG. 3 is a perspective view illustrating a beam as a wooden
building member according to the present invention;
[0013] FIG. 4 is a cross-sectional view of the beam of the present
invention, as illustrated in FIG. 3;
[0014] FIG. 5 is an explanatory diagram illustrating conversion of
timber for acquiring a laminar material from a round timber and the
grain thereof;
[0015] FIG. 6 is an explanatory diagram illustrating an edge
grain;
[0016] FIG. 7 is an explanatory diagram illustrating a flat grain;
and
[0017] FIG. 8 is an explanatory diagram illustrating a coating
portion in the post according to a preferred embodiment of the
present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] The present invention will be described in detail below with
reference to the accompanying drawings.
[0019] FIGS. 1 and 2 illustrate a wooden building member according
to a first embodiment achieved by applying the present invention to
a post which is made of a laminated lumber.
[0020] A post 10 whose member axis extends in a vertical direction
comprises: an elongated structural portion 12 having a rectangular
cross-section, and configured to receive a load applied thereto; a
coating portion 14 with which a periphery of the cross-section of
the structural portion 12 is coated over an entire length of the
structural portion 12; and an insulating portion 16 which is
interposed between the structural portion 12 and the coating
portion 14 in a laminated manner and prevents the load applied to
the structural portion 12 from transmitting to the coating portion
14.
[0021] The structural portion 12 is arranged to have any
cross-sectional area depending on various loads applied to the post
10 and is made of a laminated lumber which is obtained by
laminating laminar materials in parallel, which laminar materials
are severed into a predetermined dimension, and bonding them with
synthetic resin adhesive to form one integral part, The coating
portion 14 has a predetermined thickness t in the cross section of
the post 10 and, similarly to the structural portion 12, the
coating portion 14 is made of a laminated lumber which is obtained
by laminating laminar materials in parallel, which laminar
materials are severed into a predetermined dimension, and bonding
them with synthetic resin adhesive so as to form one integral part.
Preferably, the insulating portion 16 is composed of a
noncombustible material or an incombustible material prescribed by
the Building Codes in Japan. The term "the noncombustible material"
includes a gypsum board with thickness of 9 mm or more (thickness
of board base paper is 0.6 mm or less), a wood wool cement board
with thickness of 15 mm or more, a hard wood chip cement board with
thickness of 9 mm or more (bulk specific gravity is 0.9 or more), a
wood chip cement board with thickness of 30 mm or more (bulk
specific gravity is 0.5 or more), a pulp cement board with
thickness of 6 mm or more, and the like. The term "the
incombustible material" includes a incombustible laminated wood
with thickness of 5.5 mm or more, a gypsum board with thickness of
7 mm or more (thickness of board base paper is 0.5 mm or less), and
the like. When the gypsum board is used as the noncombustible
material or the incombustible material, the insulating portion 16
can be achieved by using the inexpensive base material having high
fire-retardant reliability which is widely used in a building or
architecture. The insulating portion 16 is fixed or semi-fixed to a
periphery of the structural portion 12 by a weak bonding system,
concretely, nailing, synthetic resin adhesive or the like, so that
various loads applied to the structural portion 12 are prevented
from being transmitted.
[0022] A function of the post 10 will be described below.
[0023] When a fire breaks out in a wooden building and the fire
spreads from the outside of the post 10, the coating portion 14 is
exposed to blaze and carbonization gradually progresses from its
outer periphery to its inward portion. When the entire coating
portion 14 is burned down for a certain amount of time, the
insulating portion 16 positioned on an inner side of the coating
portion 14 appears, and the progression of the carbonization is
stopped. At this time, since the structural portion 12 is covered
with the insulating portion 16 made of the noncombustible material
or the incombustible material, it is not exposed directly to the
blaze and the carbonization progresses very slowly, and thus the
structural portion 12 is not burned down in a short time. On the
other hand, since the surface of the post 10 is coated with the
coating portion 14, the gypsum board is not exposed to the
exterior, and thus appearance of the post 10 can be ensured. For
this reason, while the exterior appearance of the post 10 is
ensured, the fireproof capability can be improved. Since the loads
applied to the wooden building are received mainly by the
structural portion 12, the designing of the structural strength is
facilitated while the fireproof capability is ensured and further,
even if the coating portion 14 is entirely burned down, collapse of
the building does not occur.
[0024] Preferably, the predetermined thickness t of the coating
portion 14 is set according to a carbonizing speed of the base
material (laminated lumber) so that it is not burned down at least
for one hour from the beginning of firing. Concretely, since the
carbonizing speed of the laminated lumber is about 0.8 mm/min, the
predetermined thickness t may be set to 48.0 mm or more
(0.8.times.60). In this way, since it takes at least one hour for
the coating portion 14 to be completely burned down, a possibility
that the building collapses before fire extinction is greatly
reduced, and the efficiency as "the fireproof construction" of
Japanese building codes, which is very difficult to achieve with a
wooden post, can be provided.
[0025] FIGS. 3 and 4 illustrate a wooden building member according
to the second embodiment achieved by applying the present invention
to a beam which is made of a laminated lumber.
[0026] Similarly to the post 10, a beam 20 whose member axis
extends in a horizontal direction comprises, an elongated
structural portion 22 having a rectangular cross section, and
configured to receive loads applied thereto; a coating portion 24
with which three sides of the cross section of the structural
portion 22 are coated along the entire length of the structural
portion 22, and an insulating portion 26 which is interposed
between the structural portion 22 and the coating portion 24 in a
laminated manner and prevents the load applied to the structural
portion 22 from transmitting to the coating portion 24. That is,
the beam 20 has the constitution which is functionally similar to
that of the post 10, but since one surface corresponding to one
side of the cross section of the structural portion 22 should
receive various loads, only both side surfaces and a lower surface
each corresponding to the three sides of the cross section of the
structural portion 22 are coated with the coating portion 24. At
this time, since an upper surface of the structural portion 22 is
bonded to, for example, a floor material 30 made of a
noncombustible material or the like, and thus is not exposed
directly to blaze at the time of a fire. Even if the coating
portion 24 and the insulating portion 26 are not provided on the
upper surface of the structural portion 22, the fireproof
capability of the beam 20 is not adversely influenced, In the beam
20, in order to prevent the coating portion 24 and the insulating
portion 26 from easily dropping out of the structural portion 22
due to a gravitational force, it is preferable that the structural
portion 22, the coating portion 24 and the insulating portion 26
are made to be integral by using a conventionally known fastening
member 28 composed of a bolt and a nut. Since the other parts of
the constitution, function and effect are similar to those of the
post 10, the description about the post 10 should be referred
to.
[0027] In the embodiments, in order to improve the fireproof
capability of the wooden building members, it is preferable that at
least one of the structural portion and the coating portion is
constituted by a noncombustible liquid-impregnated wood building
material.
[0028] Preferably, an aluminum foil is stuck to at least a joint
appearing in an outer peripheral surface of the noncombustible
material or the incombustible material that is connected by joining
for composing the insulating portion. In this way, heat exerted on
the joint of the noncombustible material or the incombustible
material can be partially reflected, so that the carbonization of
the structural portion can be further slowed. When an aluminum foil
is stuck to the entire outer peripheral surface of the
noncombustible material or the incombustible material, heat acting
on the outer peripheral surface can be partially reflected, so that
the progression of the carbonization of the structural portion can
be effectively repressed.
[0029] A general laminar material composing a laminated lumber is
severed from a round log by conversion of timber as shown in FIG.
5. For this reason, when viewed from a direction A, the grain of
the laminar material is "edge grain" as shown in FIG. 6, whereas
when viewed from a direction B, the grain becomes "flat grain" as
shown in FIG. 7. The directional fire resistance efficiency of the
laminar material is verified. As the grain is denser, the
carbonizing speed is slower, and thus the laminar material is
preferably arranged so that the edge grain appears on the outer
peripheral surface of the wooden building member.
[0030] When the post 10 is employed as the wooden building member,
as shown in FIG. 8, the laminar material is arranged so that a long
side of the cross section of the laminar material extends
approximately perpendicularly to respective sides defining the
cross section of the structural portion 12 and their extended
lines, thereby constituting the coating portion 14. In this way,
the edge grain appears on the outer peripheral surface of the post
10, and the fireproof capability can be more improved. At this
time, in a portion C in the drawing, the flat grain appears on the
outer peripheral surface of the post 10, but since that portion is
not positioned in the approximately perpendicular direction with
respect to the respective sides defining the cross section of the
structural portion 12, no adverse influence directly acts on the
fireproof capability of the post 10. Since the predetermined
thickness t of the coating portion 14 is uniform over the entire
periphery of the cross section thereof, the coating portion 14 can
be constituted by suitably combining laminar materials having the
same dimension, and thus this is advantageous in view of the stock
management, the cost and the like. Further, since the length of
each of the sides forming the cross section of the laminar material
is reduced, as many laminar materials as possible can be severed
from one round log, thereby reducing the cost of the wooden
building members.
[0031] Also when the beam 20 is employed as the wooden building
member, by adapting the coating portion 24 similar to that of the
post 10, the similar function and effect can be produced.
[0032] The structural portion and the coating portion composing the
wooden building member may be constituted by a solid material or by
combining a laminated lumber and a solid material. When a solid
material is used for the coating portion, the predetermined
thickness t of the coating portion may be set to 60.0 mm or more
(1.0.times.60) because its carbonizing speed is about 1.0
mm/min.
[0033] The present invention can be applied not only to posts and
beams as the wooden building members but also to braces, joists and
the like.
[0034] It should be appreciated that the entire contents of
Japanese Patent Application No. 2005-230312, filed on Aug. 9, 2005,
on which the convention priority is claimed is incorporated herein
by reference.
[0035] It should also be understood that many modifications and
variations of the described embodiments of the invention will occur
to a person having an ordinary skill in the art without departing
from the spirit and scope of the present invention as claimed in
the appended claims.
* * * * *