U.S. patent application number 09/808346 was filed with the patent office on 2001-08-02 for fuel supply system for internal combustion engines having fuel leakage restricting structure.
This patent application is currently assigned to Nippon Soken, Inc.. Invention is credited to Kohama, Tokio, Saito, Kimitaka, Sato, Yasuyuki.
Application Number | 20010010217 09/808346 |
Document ID | / |
Family ID | 17760967 |
Filed Date | 2001-08-02 |
United States Patent
Application |
20010010217 |
Kind Code |
A1 |
Sato, Yasuyuki ; et
al. |
August 2, 2001 |
Fuel supply system for internal combustion engines having fuel
leakage restricting structure
Abstract
A delivery pipe of a fuel supply system for injectors mounted on
a cylinder head is divided for each injector or a group of
injectors. Divided pipe parts are coupled with each other through a
flexible member to allow flexing of the delivery pipe. Each
injector is connected with the delivery pipe through a flexible
coupling member and with the cylinder head through a flexible
cushioning member. Alternatively, a fuel passage is formed in the
cylinder head in place of the delivery pipe to supply fuel to the
injectors after heating in the cylinder head.
Inventors: |
Sato, Yasuyuki; (Niwa-gun,
JP) ; Kohama, Tokio; (Nishio-city, JP) ;
Saito, Kimitaka; (Nagoya-city, JP) |
Correspondence
Address: |
Nixon & Vanderhye P.C.
8th Floor
1100 North Glebe Road
Arlington
VA
22201
US
|
Assignee: |
Nippon Soken, Inc.
|
Family ID: |
17760967 |
Appl. No.: |
09/808346 |
Filed: |
March 15, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09808346 |
Mar 15, 2001 |
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09401785 |
Sep 22, 1999 |
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6227169 |
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Current U.S.
Class: |
123/456 ;
123/468; 123/470 |
Current CPC
Class: |
F02M 2200/16 20130101;
F02B 2075/125 20130101; F02M 2200/856 20130101; Y02T 10/123
20130101; F02M 69/465 20130101; Y02T 10/12 20130101; F02M 61/14
20130101 |
Class at
Publication: |
123/456 ;
123/470; 123/468 |
International
Class: |
F02M 001/00; F02M
055/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 13, 1998 |
JP |
10-290824 |
Claims
What is claimed is:
1. A fuel supply system for an internal combustion engine having a
plurality of cylinders, the fuel supply system comprising:
injectors mounted on the engine for injecting fuel into the engine;
and a delivery pipe coupled with the injectors for supplying the
fuel to the injectors, the delivery pipe including a plurality of
pipe parts and a flexible connecting part connecting adjacent two
of the pipe parts and having a substantially same fuel passage
diameter as that of the pipe parts, and the connecting part being
flexible to allow flexing of the pipe parts.
2. A fuel supply system of claim 1, wherein the injectors are
mounted on a cylinder head of the engine for injecting the fuel
into cylinders directly, and the flexible connecting part includes
a sealing member made of a flexible material and disposed between
longitudinally extending ends of the pipe parts.
3. A fuel supply system for an internal combustion engine having a
plurality of cylinders, the fuel supply system comprising: an
injector mounted on the engine for injecting fuel into each
cylinder of the engine; a delivery pipe coupled with the injector
for supplying the fuel to the injector; and a flexible connecting
part fitted between the delivery pipe and the injector, the
connecting part being coupled flexibly with both of the delivery
pipe and the injector.
4. A fuel supply system of claim 3, wherein the connecting part
includes a cylindrical flexible coupling member fitted around an
extension of the delivery pipe and the injector and a plurality of
flexible sealing members, one of the sealing members being disposed
between the extension of the delivery pipe and the coupling member
and another of the sealing members being disposed between the
injector and the coupling member.
5. A fuel supply system of claim 3, further comprising: a
cushioning member made of a flexible sealing material and disposed
between a cylinder head of the engine and the injector.
6. A fuel supply system for an internal combustion engine having a
plurality of cylinders, the fuel supply system comprising: an
injector mounted on the engine for injecting fuel into each
cylinder of the engine; a delivery pipe coupled with the injector
for supplying the fuel to the injector; and a cushioning member
made of a flexible sealing material and disposed between the
injector and a cylinder head of the engine to couple the injector
with the cylinder head flexibly.
7. A fuel supply system of claim 6, further comprising: a flexible
connecting part fitted between the delivery pipe and the injector,
the connecting part being coupled flexibly with both of the
delivery pipe and the injector.
8. A fuel supply system for an internal combustion engine having a
plurality of cylinders, the fuel supply system comprising: an
injector mounted on a cylinder head of the engine for injecting
fuel into each cylinder of the engine directly; and a fuel passage
formed in the cylinder head for heating the fuel therein and
supplying the heated fuel to the injector of each cylinder.
9. A fuel supply system of claim 8, further comprising: a flexible
sealing member disposed between the cylinder head and the injector,
wherein the fuel passage is formed to be in direct fluid
communication with the injector within the cylinder head.
10. A fuel supply system of claim 8, further comprising: a
connecting pipe disposed outside of the cylinder head and connected
to the injector and the fuel passage for supplying the heated fuel
from the fuel passage to the injector.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application relates to and incorporates herein by
reference Japanese patent application No. 10-290824 filed on Oct.
13, 1998.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a fuel supply system for
internal combustion engines which has an improved fuel leakage
restricting structure.
[0004] 2. Related Art
[0005] A cylinder direct injection type is proposed as an
automotive vehicle gasoline internal combustion engine as shown in
FIG. 6A to improve engine efficiency for environmental protection.
In this system, a fuel delivery pipe 1 is connected to a high
pressure fuel pump (not shown) via a fuel pipe 2. A fuel injector 4
for each cylinder is mounted on an engine cylinder head 5 so that
fuel is directly injected into a combustion chamber. The injector 4
is coupled with the delivery pipe 1 via a rubber sealing member
such as an O-ring 3. A high pressure fuel injection is attained by
the injector 4 to improve fuel spray atomization. It is important
to ensure sealing property in the fuel supply system.
[0006] The rubber sealing member 3 fitted between the delivery pipe
1 and the injector 4 tends to change its sealing characteristics
largely depending on changes in surrounding temperature. Further,
the delivery pipe 1 bows in response to the high fuel pressure by
an amount of flexing .delta. as shown in FIG. 6(B). As a result,
use of the rubber sealing member 3 is limited by surrounding
conditions (fuel pressure, temperature, etc.).
SUMMARY OF THE INVENTION
[0007] It is an object of the present invention to restrict fuel
from leaking through a sealing part in a fuel supply system for
internal combustion engines.
[0008] According to a first aspect of the present invention, a
delivery pipe is divided into a plurality parts and adjacent two of
the pipe parts of the delivery pipe are coupled with each other at
a connecting part having a substantially the same fuel passage
diameter as that of the delivery pipe. A flexible sealing member is
disposed in the connecting part.
[0009] According to a second aspect of the present invention, a
coupling member is provided between a delivery pipe and an injector
so that the coupling member is coupled flexibly with both of the
delivery pipe and the injectors.
[0010] According to a third aspect of the present invention, a
cushioning member having a sealing property is inserted between an
injector and a cylinder head to couple the injector with the
cylinder head flexibly.
[0011] According to a fourth aspect of the present invention, a
fuel passage communicated with a high pressure pump is formed in a
cylinder head to supply fuel heated by the cylinder head to an
injector.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The above and other objects, features and advantages of the
present invention will become more apparent from the following
description made with reference to the accompanying drawings. In
the drawings:
[0013] FIG. 1A is a cross sectional view showing a fuel supply
system directed to a four-cylinder engine according to a first
embodiment of the present invention;
[0014] FIG. 1B is a cross sectional view showing schematically the
deformation of a delivery pipe in the first embodiment;
[0015] FIG. 2 is a cross sectional view showing a fuel supply
system directed to a six-cylinder engine according to a second
embodiment of the present invention;
[0016] FIG. 3A is a cross sectional view showing a fuel supply
system according to a third embodiment of the present
invention;
[0017] FIG. 3B is a cross sectional view showing schematically the
deformation of a delivery pipe in the third embodiment;
[0018] FIG. 4 is a cross sectional view showing a fuel supply
system according to a fourth embodiment of the present
invention;
[0019] FIG. 5 is a cross sectional view showing a fuel supply
system according to a fifth embodiment of the present
invention;
[0020] FIG. 6A is a cross sectional view showing a conventional
fuel supply system directed to a four-cylinder engine; and
[0021] FIG. 6B is a cross sectional view showing schematically the
deformation of a delivery pipe in the conventional fuel supply
system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] The present invention will be described in further detail
with reference to various embodiments in which the same or similar
parts are designated by the same or similar reference numerals.
(First Embodiment)
[0023] In the first embodiment directed to a four-cylinder internal
combustion engine, as shown in FIG. 1A, a delivery pipe 1 connected
to a high pressure pump (not shown) via a fuel pipe 2 is divided
into two parts, a part 11 and a part 12. The delivery pipe 1 may be
divided into more than two. The parts 11 and 12 are coupled with
each other to provide a connecting part therebetween which has the
same diameter. A sealing member 6 such as an O-ring made of rubber
is interposed between longitudinal ends of the parts 11 and 12, so
that the connecting part between the parts 11 and 12 has a
flexibility. A fuel injector 4 is coupled with the delivery pipe 1
via a sealing member 3 such as an O-ring made of rubber and mounted
on a cylinder head 5 for directly injecting fuel into an engine
combustion chamber.
[0024] Thus, as shown in FIG. 1B, the deformation in flexing due to
bowing of the delivery pipe 1 is absorbed at the part including the
sealing member 6. Therefore, the amount of deformation .delta. is
reduced as opposed to the flexing of the single delivery pipe 1
(e.g., FIG. 6A).
(Second Embodiment)
[0025] In the second embodiment directed to a six-cylinder engine,
as shown in FIG. 2, the delivery pipe 1 is divided into three,
parts 11, 12 and 13. The sealing member 6 is fitted in each
connecting part defined by the longitudinal ends 11a, 12a and 13a.
It is also possible to divide it at every cylinder to absorb the
deformation more and reduce the lessening of the sealing property
to a minimum.
(Third Embodiment)
[0026] In the third embodiment, the delivery pipe 1 is in a single
pipe form for all the cylinders and has a plurality of extensions
1a extending perpendicularly. As shown in FIG. 3A, a coupling
member 7 shaped in a generally cylindrical form is fitted around a
connecting part between the injector 4 and the delivery pipe 1, and
two sealing members 3 are inserted to provide two flexible sealing
parts, one between the extension of the delivery pipe 1 and the
injector 4 and the other between the coupling member 7 and the
injector 4.
[0027] Because the connecting part between the delivery pipe 1 and
the injector 4 are thus coupled flexibly with both of the delivery
pipe 1 and the injector 4, the deformation of the delivery pipe 1
can be distributed to a part between the coupling member 7 and the
delivery pipe 1 and to a part between the connecting part 7 and the
injector 4 as shown in FIG. 3B. Thus, the deformation of the
delivery pipe 1 can be absorbed. As a result, fuel is restricted
from leaking through the connecting part, and the sealing property
can be restricted from being lessened.
[0028] Further, in the third embodiment, a cushioning member 8
having a sealing property is fitted between the injector 4 and the
cylinder head 5 and is coupled flexibly. As a result, the flexing
of the delivery pipe 1 can be absorbed by the cushioning member 8,
and the fuel is restricted from leaking through the fuel sealing
part.
(Fourth Embodiment)
[0029] In the fourth embodiment, as shown in FIG. 4, no delivery
pipe is provided. Instead, a fuel passage 9 communicated with the
fuel pipe 2 is provided to extend in the longitudinal direction in
the cylinder head 5, that is, in the direction in which the
combustion chambers are arranged. A communication passage leading
from the fuel passage 9 to the injector 4 is also provided in the
cylinder head 5. Two cushioning members 8 are fitted between the
injector 4 and the cylinder head 5.
(Fifth Embodiment)
[0030] In the fifth embodiment, as shown in FIG. 5, a connecting
pipe 10 is positioned adjacent to the outside of the cylinder head
5 to lead fuel from the fuel passage 9 to the injector 4. The
sealing member 3 is fitted between the injector 3 and the
connecting pipe 10, and the cushioning member 8 having the sealing
property is fitted between the injector 4 and the cylinder head
5.
[0031] In the fourth embodiment and the fifth embodiment, both of
the injector 4 and the fuel passage 9 are provided in the same
cylinder head 5 which has a sufficient rigidity. As a result, the
fuel passage 9 does not flex and the thermal expansion of the
cylinder head 5 does not influence on the fuel passage 9. Thus,
fuel leakage due to flexing of fuel passage can be obviated.
[0032] Further, the fuel is supplied to the injector 4 from the
fuel passage 9 provided in the cylinder head 5. The fuel is heated
by the cylinder head 5 and then supplied to the injector 4. As a
result, the flexibility of sealing member 3 and the cushioning
member 8 which have a remarkably lessened sealing property due to
hardening under an extremely low temperature condition can be
recovered quickly. This is very advantageous in preventing the fuel
from leaking through the fuel sealing part.
[0033] In addition, the fuel atomization is improved and a low
temperature engine starting ability is improved greatly, because
the fuel is heated by the cylinder head quickly.
[0034] The present invention having been described above should not
be limited to the disclosed embodiments, but may be modified in
other ways without departing from the spirit of the invention.
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