U.S. patent number 3,911,872 [Application Number 05/356,128] was granted by the patent office on 1975-10-14 for fuel supply systems for internal combustion engines.
This patent grant is currently assigned to The Lucas Electrical Company Limited. Invention is credited to Ronald William Hughes.
United States Patent |
3,911,872 |
Hughes |
October 14, 1975 |
Fuel supply systems for internal combustion engines
Abstract
A fuel supply system for an internal combustion engine comprises
a pump feeding fuel to one or more injector nozzles. A digital
electronic fuel control unit controls the flow of fuel to the
nozzles in response to signals from a digital encoder whose output
is dependent upon the angle of a vane controlling the admission of
combustion air into the engine. The digital encoder includes an arm
mounted on a spindle carrying the vane. The arm has a series of
contacts thereon which move relative to fixed contact areas as the
vane pivots with the spindle so that a digital output is obtained
in accordance with the angle of the vane.
Inventors: |
Hughes; Ronald William
(Birmingham, EN) |
Assignee: |
The Lucas Electrical Company
Limited (Birmingham, EN)
|
Family
ID: |
10184990 |
Appl.
No.: |
05/356,128 |
Filed: |
May 1, 1973 |
Foreign Application Priority Data
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|
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May 13, 1972 [GB] |
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22781/72 |
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Current U.S.
Class: |
123/494;
261/DIG.74 |
Current CPC
Class: |
F02D
41/28 (20130101); Y10S 261/74 (20130101); F02D
2041/283 (20130101); F02D 2200/0404 (20130101) |
Current International
Class: |
F02D
41/00 (20060101); F02D 41/24 (20060101); F02D
005/02 () |
Field of
Search: |
;123/32EA,32AE,139E,119 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
"Electronic Fuel Injection Reduces Automotive Pollution," M.
Williams, Electronics, Sept. 11, 1972, pp. 121-125..
|
Primary Examiner: Myhre; Charles J.
Assistant Examiner: Cangelosi; Joseph
Attorney, Agent or Firm: Holman & Stern
Claims
I claim:
1. A fuel supply system including a throttle valve for controlling
the admissions of combustion air to an engine and having an
angularly movable spindle, a digital encoder for said throttle
valve for producing a digital output signal corresponding to the
angular position of the spindle, and a digital electronic fuel
control unit responsive to said output signal of the digital
encoder for controlling the rate at which fuel is supplied to an
engine in accordance with said output signal of the digital
encoder, said encoder including an arm mounted for angular movement
with the spindle, a plurality of contacts mounted on said arm, the
number of said contacts corresponding to the number of bits of said
digital output signal, and a plurality of fixed digitally coded
contact paths equal in number to and arranged in a one-to-one
contacting relationship with said contacts on said arm and relative
to which the contacts on the arm are movable upon angular movement
of the spindle so as to generate a plurality of different digitally
coded output signals.
2. A fuel supply system as claimed in claim 1, including at least
one fuel injector nozzle for supplying fuel to the engine, and
wherein the fuel control unit is arranged to control the flow of
fuel to the said at least one nozzle.
3. A fuel supply system as claimed in claim 2, wherein a pump is
arranged to supply fuel to the control unit which controls flow of
fuel therefrom to the said at least one nozzle.
4. A fuel supply system as claimed in claim 2, wherein a pump is
provided for supplying fuel, and a variable speed motor controlled
by the fuel control unit drives the pump.
5. A fuel supply system as claimed in claim 1, wherein one of the
contacts on the arm is permanently in contact with an arcuate
conductive area and other contacts on the arm are movable over
arcuate rows of alternately conductive and non-conductive areas,
the conductive areas of each arcuate row being connected to a
terminal so that for any position of the spindle a predetermined
number of the terminals are connected to the said arcuate
conductive area and the remainder are isolated from the said
arcuate conductive area.
6. A fuel supply system as claimed in claim 5, wherein the
conductive areas are arranged so that only one output changes at
any time as the spindle is turned.
Description
This invention relates to fuel supply systems for internal
combustion engines.
A fuel supply system in accordance with the invention includes a
throttle valve for controlling the admission of combustion air to
an engine and having an angularly movable spindle, a digital
encoder for said throttle valve for producing a digital output
corresponding to the angular position of the spindle, and a digital
electronic fuel control unit responsive to the output of the
digital encoder for controlling the rate at which fuel is supplied
to the engine in accordance with the output of the digital
encoder.
In the accompanying drawings
FIGS. 1 and 2 are diagrammatic representations of two examples of
fuel supply systems in accordance with the invention, for an
internal combustion engine, and
FIGS. 3 and 4 are mutually perpendicular sections through a
throttle valve which can be employed in either system.
The system shown in FIG. 1 includes a digital electronic fuel
control device 10 which controls the supply of fuel, pressurised by
a pump 11, to injection nozzles 12 in an air intake manifold 13 of
the engine. The digital control device 10 has inputs from a speed
sensing device 14 and from a digital encoder 15 associated with a
throttle 16 which controls admission of combustion air to the
manifold 13 under the control of a pedal 17. The timing of the
injections is controlled by a timing device 18. The quantity
injected in each cycle is controlled by the device 10.
In the system shown in FIG. 2, a single spray nozzle 19 is used
which sprays fuel into air intake downstream of the throttle. In
this case, digital control device 20 is used to drive a variable
speed electric motor 21 which drives a pump 22 supplying the nozzle
19. The rate of injection is controlled by the device 20.
In each case, the throttle valve 16 has a spindle 23 which is
turned to move a vane 24 within a passage through the throttle
valve body. An electrically insulating arm 25 is mounted on the
spindle 23 and a row of contacts 26 on this arm 25 engage a printed
circuit board 27 mounted on the body. One of these contacts is
permanently in contact with an arcuate conductive area 27a on this
board. The remaining contacts 26 run over arcuate rows of
alternately conductive and non-conductive areas on the board 27,
the conductive areas of each arcuate row being connected together
and thereby to an associated one of a plurality of terminals 27b on
the board. Thus, for any position of the spindle a predetermined
number of the terminals 27b are connected to the area 27a and the
remainder are isolated from the area 27a. Preferably the conductive
areas on the board are arranged to give a Gray, coded digital
output, as is already known in shaft encoders, so that only one
output changes at any time as the spindle is turned.
The encoder 15 provides a digital input into the digital control
device 10 or 20, which, taken in combination with the signal from
the speed sensing device 14 determines the output of the device 10
to control the rate of fuel input.
Details concerning the digital fuel control circuits 10 and 20,
speed centers 14, and timing device 18 may be found, for example,
in U.S. Pat. No. 3,689,753, issued Sept. 5, 1972, to Williams et al
and assigned to the same assignee as the present application, said
patent being expressly incorporated herein by reference.
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