Internal-combustion engines – Charge forming device – With fuel pump
Reexamination Certificate
2000-09-26
2001-07-17
Yuen, Henry C. (Department: 3747)
Internal-combustion engines
Charge forming device
With fuel pump
C123S514000
Reexamination Certificate
active
06260540
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a fuel supply system mounted in an automobile fuel tank and used for supplying fuel under pressure to an injector for emitting a jet of fuel to an automobile engine.
2. Description of the Related Art
FIGS. 5 and 6
show a conventional fuel supply system shown in International Publication No. WO96/23967:
FIG. 5
is a side sectional view and
FIG. 6
is a plan view.
In these drawings, reference numeral
1
denotes a fuel supply system, which comprises a cover
3
, a fuel pump
4
, a fuel filter
5
, a pressure regulator
6
, a fuel level gauge
7
, an electric connector
8
and a discharge pipe
9
, these being integrally formed and suspended down the open side
2
a
of a metal or plastic fuel tank
2
.
The fuel filter
5
is formed with a holding member
5
a
made of conductive plastic material and a filter element
5
b
contained therein, these being liquid-tightly sealed by welding the cover
3
to a boundary portion
10
. The holding member
5
a
holds the fuel pump
4
in its center, the pressure regulator
6
and the fuel level gage
7
in its lower end portion. A gasket
11
for keeping air-tightness is also held between the cover
3
and the fuel tank
2
.
In the holding member
5
a
of the fuel filter
5
, an inlet portion
12
as a fuel inlet for the fuel filter
5
is provided on the upper inner peripheral side of the holding member
5
a
and coupled to the discharge pipe
13
of the fuel pump
4
. A pipe
14
(shown by a chain line) forming a first fuel outlet out of the two fuel outlets of the holding member
5
a
extends upward along the axial direction from the lower end of the holding member
5
a
. The pipe
14
communicates with the discharge pipe
9
provided to the cover
3
whereby to form a fuel passage for use in supplying filtered fuel. A return pipe
15
forming a second fuel outlet is provided in the lower side portion of the holding member
5
a
. A strainer
16
is used for filtering off foreign matter such as iron powder in the fuel tank
2
when the fuel in the fuel tank
2
is sucked into the fuel pump
4
.
The electric connector
8
is formed integrally with the cover
3
by embedding a plurality of terminal pins
8
a
and
8
b
in the insulating plastic material of the cover
3
by direct insert molding. The terminal pins
8
a
and
8
b
of the electric connector
8
are connected to one side of a power supply relay (not shown) and a battery (not shown) outside the fuel tank
2
. Moreover, the electric connector
8
is also used to supply power to the motor (not shown) of the fuel pump
4
via a lead wire
20
within the fuel tank
2
.
Further, an electric signal derived from the fuel level gage
7
indicative of the liquid level is taken out of the fuel tank
2
similarly via a terminal pin (not shown) and a lead wire (not shown).
In the fuel supply system
1
thus arranged, the fuel in the fuel tank
2
is sucked through the strainer
16
when the fuel pump
4
is supplied with power via the electric connector
8
and the lead wire
20
and operated. Then the fuel flows in a passage
17
in the direction of an arrow A after being discharged from the discharge pipe
13
and passes through the filter element
5
b
before reaching a lower space
18
beneath the filter element
5
b.
Further, part of the fuel is returned to the fuel tank
2
again by the pressure regulator
6
for the purpose of adjusting the fuel pressure, whereas the rest of fuel is caused to flow in the pipe
14
in the direction of an arrow B and supplied to the injector of a fuel injection system of an engine (not shown) via the discharge pipe
9
.
As static electricity is generated because of intense friction between the fuel and the filter element
5
b
when the fuel passes therethrough during the process of feeding the fuel, the static electricity has been designed to be dissipated from a relay terminal
19
secured to the inner peripheral portion of the holding member
5
a
via the lead wire
20
toward the terminal
8
b.
However, the prior art fuel supply system above may be used in the electrostatically charged condition because it is not possible to externally confirm the slip-off of the relay terminal
19
secured to the holding member
5
a
used to dissipate the static electricity or the disconnection of the lead wire
20
.
When the fuel pump
4
is operated for hours, moreover, the filter element
5
b
may be clogged with powder deriving from the wearing of slide parts such as brushes in the fuel pump
4
and a commutator and/or the foreign matter passed through the strainer
16
, for example, may be introduced into the fuel pump
4
. As a result, the operation of the engine has become unstable because the fuel pump
4
is unable to sufficiently supply the fuel to the injector of the fuel injection system of the engine.
SUMMARY OF THE INVENTION
An object of the present invention intended to solve the foregoing problems is to provide a fuel supply system for making it possible to check whether or not static electricity is being discharged and a static discharge device.
Another object of the present invention is to provide a fuel supply system for making it possible to inform a decrease in the supply amount of fuel to an engine whenever a filter element is clogged with foreign matter or a fuel pump malfunctions.
A fuel supply system according to the invention comprises: a cover portion fitted in the opening of a fuel tank and equipped with a discharge pipe; a fuel pump for supplying fuel in the fuel tank under pressure to the injector of an engine via the discharge pipe; a fuel filter for filtering the fuel discharged from the fuel pump; a static discharge circuit fitted to the cover portion and electrically connected to a relay terminal electrically connected to the fuel filter and used for charging and discharging the static voltage generated in the fuel filter; and operation confirming display means whose operation is based on the charging and discharging of the static discharge circuit.
The static discharge circuit comprises: voltage comparator means for comparing the voltage of the supplied static electricity with a comparative voltage which is set with a minimum necessary flow rate of fuel flowing in the fuel filter as a reference; waveform shaping means for shaping a signal from the voltage comparator means; and a switching element for conducting the static electricity generated in the fuel filter to a grounding portion by a signal from the waveform shaping means.
Operation confirming signal output means and the operation confirming display means are operated by a signal from the waveform shaping means.
Further, a fuel supply system comprises: a cover portion fitted in the opening of a fuel tank and equipped with a discharge pipe; a fuel pump for supplying fuel in the fuel tank under pressure to the injector of an engine via the discharge pipe; a fuel filter for filtering the fuel discharged from the fuel pump; a static discharge circuit fitted to the cover portion and electrically connected to a relay terminal electrically connected to the fuel filter and used for charging and discharging the static voltage generated in the fuel filter; and operation confirming signal output means for outputting a signal based on the charging and discharging of the static discharge circuit.
A static discharge device according to the invention comprises: voltage comparator means for comparing the voltage of the supplied static electricity with a comparative voltage which is set with a minimum necessary flow rate of fuel flowing in the fuel filter as a reference; waveform shaping means for shaping a signal from the voltage comparator means; a switching element for conducting the static electricity generated in the fuel filter to a grounding portion; and operation confirming display means operated by a signal from the waveform shaping means.
Further, a static discharge device comprises: voltage comparator means for comparing the voltage of the supplied static electricity with a comparative volt
Hiraiwa Masaru
Kuwada Hisashi
Gimie Mahmoud
Mitsubishi Denki & Kabushiki Kaisha
Sughrue Mion Zinn Macpeak & Seas, PLLC
Yuen Henry C.
LandOfFree
Fuel supply system and static discharge device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fuel supply system and static discharge device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fuel supply system and static discharge device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2493486