U.S. patent application number 09/287348 was filed with the patent office on 2001-11-29 for fuel hose resin coupling.
Invention is credited to BITO, SHINICHI, GOTO, HISATSUGU, KATO, TAKAYUKI, KOIKE, MASAKI, MIYAMOTO, YASUSHI.
Application Number | 20010046111 09/287348 |
Document ID | / |
Family ID | 14122885 |
Filed Date | 2001-11-29 |
United States Patent
Application |
20010046111 |
Kind Code |
A1 |
KOIKE, MASAKI ; et
al. |
November 29, 2001 |
FUEL HOSE RESIN COUPLING
Abstract
A resin coupling connected to a resin fuel hose is provided. An
O-ring is fitted in the inner cylindrical wall of the pipe
inserting section of a coupling body. The electrical resistance of
the coupling body meets 10.sup.6 to 10.sup.10 .OMEGA..cndot.cm in
volume resistivity, or 10.sup.6 to 10.sup.10 .OMEGA.in surface
resistivity.
Inventors: |
KOIKE, MASAKI; (ICHINOMIYA,
JP) ; BITO, SHINICHI; (AMA--GUN, JP) ;
MIYAMOTO, YASUSHI; (OKAZAKI-SHI, JP) ; GOTO,
HISATSUGU; (NISSHIN-SHI, JP) ; KATO, TAKAYUKI;
(AICHI-GUN, JP) |
Correspondence
Address: |
PILLSBURY MADISON & SUTRO
INTELLECTUAL PROPERTY GROUP
NINTH FLOOR EAST TOWER
1100 NEW YORK AVENUE NW
WASHINGTON
DC
200053918
|
Family ID: |
14122885 |
Appl. No.: |
09/287348 |
Filed: |
April 7, 1999 |
Current U.S.
Class: |
361/215 |
Current CPC
Class: |
F16L 33/24 20130101;
F16L 25/01 20130101; F16L 47/06 20130101; F16L 11/127 20130101 |
Class at
Publication: |
361/215 |
International
Class: |
H05F 003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 7, 1998 |
JP |
10-094899 |
Claims
What is claimed is:
1. A fuel hose resin coupling for connecting a resin fuel hose with
a metal pipe, comprising: a coupling-body to be inserted into the
resin fuel hose and having a pipe inserting section into which the
metal pipe is to be inserted; and an O-ring fitted in said pipe
inserting section and disposed between said coupling body and the
metal pipe, wherein an electrical resistance of said coupling body
meets 10.sup.6 to 10.sup.10 .OMEGA. in surface resistivity.
2. A fuel hose resin coupling according to claim 1, wherein said
coupling body has an electrically conductive film on a surface
thereof, and has the electrical resistance of 10.sup.6 to 10.sup.10
.OMEGA. in the surface resistivity.
3. A fuel hose resin coupling according to claim 1, further
comprising an electrically conductive elastic member being arranged
on a bottom of said pipe inserting section.
4. A fuel hose resin coupling according to claim 3, wherein surface
resistivity of said elastic member is smaller than that of said
coupling body.
5. A fuel hose resin coupling according to claim 1, wherein the
electrical resistance of said coupling body meets 10.sup.7 to
10.sup.9 .OMEGA. in the surface resistivity.
6. A fuel hose resin coupling according to claim 3, wherein volume
resistivity of said elastic member is smaller than that of said
coupling body.
7. A fuel hose resin coupling for connecting a resin fuel hose with
a metal pipe, comprising: a coupling body to be inserted into the
resin fuel hose and having a pipe inserting section into which the
metal pipe is to be inserted; and an O-ring fitted in said pipe
inserting section and disposed between said coupling body and the
metal pipe, wherein an electrical resistance of said coupling body
meets 10.sup.6 to 10.sup.10 .OMEGA..cndot.cm in volume
resistivity.
8. A fuel hose resin coupling according to claim 7, further
comprising an electrically conductive elastic member being arranged
on a bottom of said pipe inserting section.
9. A fuel hose resin coupling according to claim 8, wherein volume
resistivity of said elastic member is smaller than that of said
coupling body.
10. A fuel hose resin coupling according to claim 7, wherein the
electrical resistance of said coupling body meets 10.sup.7 to
10.sup.9 .OMEGA..cndot.cm in the volume resistivity.
11. A fuel hose resin coupling according to claim 8, wherein
surface resistivity of said elastic member is smaller than that of
said coupling body.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a resin coupling connected to a
resin fuel hose, and more particularly to a resin coupling which is
so designed that an O-ring is fitted in the inner wall of the pipe
inserting section of the coupling body.
[0003] The present application is based on Japanese Patent
Application No. Hei. 10-94899, which is incorporated herein by
reference.
[0004] 2. Description of the Related Art
[0005] In this specification, the term "electrical deterioration of
resin" is intended to means that current flows in the contact part
of different kind of members, so that the resin is deteriorated.
The resin electrical deterioration may includes electrolytic
deterioration and thermal (Joule heat) deterioration.
[0006] For instance, Japanese Patent Publication No. Hei. 4-224394
is not a literature which does not particularly relates to the
invention, but a literature which shows a general technical level
and is herein incorporated by reference.
[0007] A resin fuel hole generally requires compound
characteristics such as gasoline resistance, gasohol resistance,
gasoline permeability resistance, and moisture permeability
resistance. Therefore, generally, a hose body 12 is of a
multi-layer structure as shown in FIG. 1.
[0008] For instance, the resin fuel hole is designed as follows: A
body layer 14 is formed of polyamide such as nylon 11, nylon 12, or
the like, excellent in gasohol resistance and moisture permeability
resistance, and having flexibility. And an inner layer (the
innermost layer) 16 of fluororesin material is formed which is much
higher in characteristics such as gasoline resistance and gasoline
permeability resistance than the nylon 11 or nylon 12 inside the
body layer 14 (cf. U.S. Pat. No. 5,383,087).
[0009] The inner surface of the resin fuel hole is liable to be
electrostatically charged by the flow of fuel. Therefore, it is
necessary that the amount of electrostatic charge is suppressed to
a predetermined value, whereby to prevent the occurrence of
electrostatic trouble.
[0010] For this purpose, generally, the inner layer 16 is formed
with a material whose electrical resistance is lower than a
predetermined value (usually 1.times.10.sup.8 .OMEGA.) to make
static electricity generate easily, so that the static electricity
(charge) is allowed to leak to other electrically conductive
members.
[0011] That is, the static electricity generated in the inner layer
16 is removed through a nipple 20 of an electrically conductive
quick connector and through a metal pipe 22 which is connected to
the quick connector 18 and grounded (cf. FIG. 2).
[0012] The structure of the quick connector 18 is such that an
O-rings are fitted in the inner cylindrical wall of the pipe
inserting section 26 of the coupling body 24. This is to connect
the metal pipe to the coupling 18 in one action.
[0013] On the other hand, the electrically conductive quick
connector is mainly made of resin in view of assembling work,
productivity (injection molding can be utilized) and the reduction
of weight,
[0014] In order to discharge the static electricity (charge), the
quick connector is generally made of a resin which is lower than
volume resistivity 10.sup.6 .OMEGA..cndot.cm or lower than surface
resistivity 10.sup.6 .OMEGA..
[0015] It has been found that the resin quick connector having
electrical resistance is accelerated in electrical
deterioration.
SUMMARY OF THE INVENTION
[0016] In view of the foregoing, an object of the invention is to
provide a fuel hose resin coupling in which the coupling body is
scarcely electrically deteriorated.
[0017] The inventors have conducted intensive research on the
solution of the above-described problem, and found that the cause
for the electrical deterioration of the resin coupling is as
follows:
[0018] In the discharge path (or charge leak path) of the inner
layer 16, the coupling body 24, and the metal pipe 22, a gap which
is for the assembling of the metal pipe 22 and the coupling 18 is
provided between the metal pipe 22 and the pipe inserting section
26 of the coupling body 24. The gap between the metal pipe 22 and
the pipe inserting section 26 is sealed with O-rings 28. Because of
the function of the O-ring 28, it is not permitted that its
electrical resistance is low to the extent that static electricity
can leak. In order to make the electrical resistance low, it is
necessary that a large quantity of carbon black is employed to
reduce the electrical resistance of the O-ring; however, in order
to seal the gap well, it is not suitable to employ a large quantity
of carbon black.
[0019] Therefore, the charge moved from the inner layer 16 to the
coupling body 24 behaviors as follows: that is, when the metal pipe
22 is brought into point-contact with the coupling body because of
the vibration of the traveling vehicle, current flows in the
contact part of the coupling body 24 and the metal pipe 22. This
current is a factor which expedites the deterioration (or
dissolution) of the coupling body 24 of resin.
[0020] In this connection, it has been found that, if the
electrical resistance of the coupling body is in a predetermined
range, then the current which expedites the deterioration of the
coupling body 24 does not flow in the contact part of the coupling
body 24 and the metal pipe 22. As a result, the following fuel hose
resin coupling has been thought of.
[0021] The fuel hose resin coupling according to the present
invneiton has an O-ring fitted in the inner cylindrical wall of the
pipe inserting section of a coupling body. A specific feature of
the resin coupling resides in that the electrical resistance of the
coupling body meets 10.sup.6 to 10.sup.10 .OMEGA..cndot.cm in
volume resistivity or 10.sup.6 to 10.sup.10 .cndot. in surface
resistivity.
[0022] In this connection, it is preferable that the coupling body
has an electrically conductive film, because the surface
resistivity of the coupling body can be readily set in the
above-described range.
[0023] In addition, it is preferable that an electrically
conductive elastic member is arranged on the bottomed step of the
pipe inserting section. In this case, it is preferable that each of
the volume and surface resistivitis of the elastic member is
smaller than those of the coupling body, because the discharge path
is maintained well.
[0024] Features and advantages of the invention will be evident
from the following detailed description of the preferred
embodiments described in conjunction with the attached
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In the accompanying drawings:
[0026] FIG. 1 is a cross sectional view of an example of a fuel
hose;
[0027] FIG. 2 is a sectional view of an example of a resin
coupling, which constitutes an embodiment of the invention;
[0028] FIG. 3 is a sectional view showing another assembling
example of the resin coupling; and
[0029] FIG. 4 is a sectional view of the resin coupling on which an
electrically conductive film is formed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] A resin coupling of the invention will be described mainly
with reference to FIG. 2.
[0031] The resin coupling of the invention is connected to a resin
fuel hose (or a hose body) 12, and O-rings 28 are fitted in the
inner cylindrical wall of the pipe inserting section 26 of the
coupling body 24. That is, it is a quick connector.
[0032] In the embodiment shown, the hose body 12 is of a
double-layer structure having a body layer 14 and an innermost pipe
layer, namely, an inner layer 16; however, it may be of a single
layer structure, or a multi-layer structure consisting of three
through six layers. In FIG. 2, reference numeral 25 designates a
hose protector of elastomer.
[0033] An insulating resin forming the body layer 14 may be any
resin which meets characteristics required by the fuel hose;
however, it is preferable to employ nylon 11 or nylon 12 which is
excellent in gasohol resistance, small in water absorption
coefficient, flexible, and high in low temperature resistance.
[0034] Furthermore, it is preferable that the inner layer 16 inside
the hose body layer 14 is made of an electrically conductive
fluoro-resin material.
[0035] In the case where the body layer 14 is of nylon, and the
inner layer 16 is of fluoro-resin, since those materials cannot be
connected together by welding, usually an adhesive layer is
interposed between the body layer 14 and the inner layer 16.
[0036] In the resin coupling of the invention, it is a specific
essential feature that the electrical resistance of the coupling
body 14 meets 10.sup.6 to 10.sup.10 .OMEGA..cndot.cm (preferably
10.sup.7 to 10.sup.9 .OMEGA..cndot.cm) in volume resistivity or
10.sup.6 to 10.sup.10 .OMEGA.(preferably 10.sup.7 to 10.sup.9
.OMEGA.) in surface resistivity.
[0037] If the electrical resistance of the quick connector exceeds
the upper limit value, then the electrical resistance is too high
to move the static electricity generated inside the hose through
the quick connector 18 to the metal pipe 22. On the other hand, the
electrical resistance is lower than the lower limit value, then a
great current flows in the discharge path; that is, the contact of
the coupling body 24 and the metal pipe 22, so that, in the quick
connector, the resin may be electrically deteriorated.
[0038] The quick connector may have the above-described range of
electrical resistance as follows: That is, it may be formed with a
hard resin material which is obtained by mixing electrically
conductive filler with hard resin material. Alternatively, as shown
in FIG. 4, an electrically conductive film 30 may be formed on the
surface of the coupling body 24 which is formed with hard resin
material.
[0039] Preferably, the hard resin material is polyacetal (POM),
polyamide (PA), poly vinyl chloride (PVC), polyester, or
polypropylene.
[0040] Preferably, the electrically conductive filler is carbon
black, graphite, or stainless steel, and high electrically
conductive metal material such as copper, silver and gold.
[0041] Means for forming the electrically conductive film 30 may be
electrically conductive paining coating, electrically conductive
ink printing, electrically plating, vacuum evaporating, flame
coating, sputtering, or ion plating. However, in view of the
productivity, it is preferably to employ the electrically
conductive paint coating or electrically conducting ink
printing.
[0042] The electrically conductive paint/ink is the mixture of
electrically conductive filler, and binder such as synthetic resin,
solvent and additive which is hardened to form an electrically
conductive paint. The electrically conductive filler may be those
which have been described above. However, in the case of
electrically conductive film, it is preferable that it is carbon
black or graphite which is not expensive, because it is not
required that the electrically conductive film is high in
electrical conductivity.
[0043] In addition, it is preferable that the binder, namely, the
synthetic resin is high in adhesion with the body layer 14. For
instance, in the case where the body layer is made of nylon 11 and
nylon 12, it is preferable that the synthetic resin is
polyurethane, acrylic resin (including ultraviolet-hardened type),
and alkyd resin because they are high in weather resistance.
[0044] The surface of the coupling body 24 has the electrically
conductive film. Therefore, the coupling body which has an
electrical resistance of 10.sup.6 to 10.sup.10 .OMEGA. in surface
resistivity, can be readily prepared.
[0045] As shown in FIG. 3, an electrically conductive elastic
member 32 is arranged on the bottomed step 27 of the pipe inserting
section 26. Each of the volume and surface resistivities of the
elastic member 32 is made smaller than those of the coupling body
24, whereby a direct and stable discharge path can be formed by
electrical conduction (including charge movement) . Preferably,
each of the volume and surface resistivities of the elastic member
32 is set not less than 0.1% and less than 10% of those of the
coupling body 24. Therefore, electrical conduction is smoothly
carried out from the coupling body 24 to the metal pipe 22; that is
no charge is stored in the coupling body 24, and the flow of large
current through the contact part of the coupling body 24 and the
metal pipe 22 is more positively prevented.
[0046] In the embodiment, the elastic member 32 is of electrically
conductive rubber; however, the invention is not limited thereto or
thereby; that is, it may be a coil spring or leaf spring which is
made of metal or electrically conductive hard plastic material.
[0047] In the fuel hose resin coupling of the invention, the
electrical resistance of the coupling body meets 10.sup.6 to
10.sup.10 .OMEGA..cndot.cm in volume resistivity or 10.sup.6 to
10.sup.10 .OMEGA. in surface resistivity. Therefore, the resin
coupling of the invention has the following functions and effects
or merits:
[0048] If the electrical resistance of the quick connector 18
exceeds the upper limit value, then the electrical resistance
becomes excessively high, so that it becomes difficult for the
static electricity generated inside the hose to move to the metal
pipe 22 through the quick connector 18. On the other hand, if the
electrical resistance is lower than the lower limit value, a large
current flows in the coupling body 24 and the metal pipe 22 in the
discharge path, so that the quick connector 18 may be electrically
deteriorated.
[0049] Hence, in the fuel hose resin coupling of the invention, the
resin body is scarcely electrically deteriorated.
[0050] Furthermore, since the surface of the coupling body has the
electrically conductive film, it is readily possible to allow the
coupling body to have the above-described surface resistivity.
[0051] In the fuel hose resin coupling of the invention, the
electrically conductive elastic member is arranged on the bottomed
step of the pipe inserting section. This feature makes it possible
to form a direct and stable discharge path by discharge
movement.
[0052] Hence, electrical conduction is smoothly carried out from
the coupling body to the metal pipe. Furthermore, the coupling body
is not charged. The difficulty can be prevented more positively
that a large current flows in the contact part of the coupling body
24 and the metal pipe 22. Therefore, the electrical deterioration
of the resin coupling body can be prevented more positively.
[0053] Although the invention has been described in its preferred
form with a certain degree of particularity, it is understood that
the present disclosure of the preferred form can be changed in the
details of construction and in the combination and arrangement of
parts without departing from the spirit and the scope of the
invention as hereinafter claimed.
* * * * *