Gas separation – Combined or convertible – In motor vehicle
Reexamination Certificate
2001-01-17
2003-02-11
Simmons, David A. (Department: 1724)
Gas separation
Combined or convertible
In motor vehicle
C055S486000, C055S487000, C123S19800E, C156S069000, C156S294000, C156S304200, C156S304600, C156S499000
Reexamination Certificate
active
06517595
ABSTRACT:
INCORPORATION BY REFERENCE
The disclosure of Japanese Patent Application No. 2000-7959 filed on Jan. 17, 2000 including the specification, drawings and abstract is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an intake duct for introducing outside air into an air cleaner of an internal combustion engine, for example, a vehicle engine.
2. Discussion of Related Art
An intake duct of this type normally has a hollow cylindrical shape, and the outside air admitted into an air cleaner through the duct generates intake noise such as air-column resonance. In order to reduce such intake noise, an intake duct disclosed in, for example. Japanese Application Laid-Open No. SHO 63-285257 uses an air-permeable porous material to form a part of a circumferential wall of a duct body.
As shown in
FIG. 6
, in the aforementioned intake duct
51
, an intake port
53
for admitting the outside air is formed at one end of a duct body
52
. Moreover, a connection port
54
connected to an air cleaner (not shown) through a hose (not shown) or the like is formed at the other end of the duct body
52
.
A circumferential wall
55
between the intake port
53
and the connection port
54
of the duct body
52
provides a curved surface over the entire circumference thereof. An opening
56
is formed in the circumferential wall
55
, and a porous material
57
is bonded to cover the opening
56
. The porous material
57
is formed in a shape matching the shape of the circumferential wall
55
of the duct body
52
. For example, a non-woven fabric article to which a desired shape is given by press molding is used as the porous material
57
. The non-woven fabric article may be formed from synthetic resin fibers that are pressed without being woven.
By forming a part of the circumferential wall
55
of the duct body
52
from the air-permeable porous material
57
, the balance between the amount of outside air admitted through the intake port
53
and the amount of outside air admitted through the porous material
57
can be adjusted. As a result, a natural frequency of the intake duct
51
is varied such that air-columnar resonance in a range of normal use of the vehicle engine is suppressed, and the intake noise is reduced.
Thus, the intake noise can be effectively reduced by using the porous material
57
to form a part of the circumferential wall
55
of the duct body
52
. In the above-described conventional structure, however, the porous material
57
forming a part of the circumferential wall
55
of the duct body
52
needs to be formed or shaped in accordance with the shape of the circumferential wall
55
of the duct body
52
. Thus, the production of the conventional intake duct
51
requires the step of forming the porous material
57
to match the shape of the circumferential wall
55
, using molds having complicated structures for forming the porous material
57
as well as the duct body
52
. Moreover, respective molds for the porous material
57
and the duct body
52
need be prepared for each intake duct
51
to be produced. Thus, the intake duct
51
of the conventional structure may suffer from undesirably high manufacturing cost.
Moreover, a gap or clearance between the porous material
57
and the circumferential wall
55
of the duct body
52
may allow the outside air to be admitted into the duct body
52
. If such a gap is formed, the amount of outside air admitted through the porous material
57
and the amount of outside air introduced without passing through the porous material
57
is unbalanced, thereby possibly making it difficult to suppress the aircolumnar resonance in the range of normal use of the vehicle engine. Therefore, it is required to accurately bond the porous material
57
to the duct body
52
, or to bond the porous material
57
to the duct body
52
via a separate sealing material (not shown), which may result in a significant increase in the manufacturing cost of the intake duct
51
.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an intake duct in which intake noise can be effectively reduced and which can be produced at a relatively low cost, and to provide a method of producing such an intake duct.
To accomplish the object and other objects, there is provided according to the first aspect of the invention an intake duct adapted to introduce outside air into an air cleaner of an internal combustion engine, which comprises: a hollow duct body including a circumferential wall formed of a resin, with the duct body having an opening formed in a portion of the circumferential wall to provide an end face that lies in a substantially flat plane. A piece of non-woven fabric is joined to the duct body so as to cover the opening. Further, the piece of non-woven fabric is fixed to the duct body by having some of the resin of the duct body penetrate into and solidify with the non-woven fabric.
In the intake duct constructed as described above according to the invention, the opening of the duct body is formed in a flat plane, and the piece of non-woven fabric is simply formed in a flat shape. This eliminates a need to form the piece of non-woven fabric into a curved profile, or the like, corresponding to the shape of the circumferential wall of the duct body. This leads to a greatly simplified structure of a mold for forming the piece of non-woven fabric, and also eliminates a need to prepare a mold for the non-woven fabric for each type of intake duct. Accordingly, the manufacturing cost of the intake duct can be significantly reduced.
The piece of non-woven fabric is joined and fixed to the duct body by having some of the resin of the duct body penetrate into the interior of the article. This arrangement makes it possible to prevent a gap or clearance from being formed between the circumferential wall of the duct body and the non-woven fabric, without requiring accurate formation of the non-woven fabric or providing a sealing material between the duct body and the non-woven fabric. Accordingly, in the intake duct, a suitable balance between the amount of outside air admitted through the non-woven fabric and the amount of outside air admitted without passing through the non-woven fabric is favorably maintained, and intake noise can be effectively reduced during normal operation of the engine. Furthermore, since accurate formation of the non-woven fabric and the sealing material are not needed, the manufacturing cost of the intake duct can be further reduced.
REFERENCES:
patent: 5275636 (1994-01-01), Dudley et al.
patent: 5487874 (1996-01-01), Gibboney, Jr.
patent: 5571242 (1996-11-01), Demorest
patent: 5762858 (1998-06-01), Maeda et al.
patent: 5806480 (1998-09-01), Maeda et al.
patent: 5914415 (1999-06-01), Tago
patent: 5947082 (1999-09-01), Choi et al.
patent: 6171369 (2001-01-01), Schultink et al.
patent: 6183536 (2001-02-01), Schultink et al.
patent: 6214093 (2001-04-01), Nabata et al.
patent: 63-285257 (1988-11-01), None
patent: 01253559 (1989-10-01), None
patent: 5-15568 (1993-04-01), None
patent: 5-126002 (1993-05-01), None
patent: 08207164 (1996-08-01), None
patent: 11343938 (1999-12-01), None
patent: 2001012324 (2001-01-01), None
Hirose Yoshikazu
Ishihara Hidetoshi
Kino Hitoshi
Komori Takahiro
Tanaka Yoshikazu
Pham Minh-Chau T.
Simmons David A.
Toyoda Gosei Co,., Ltd.
LandOfFree
Intake duct and method of producing the same does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Intake duct and method of producing the same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Intake duct and method of producing the same will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3146225