US3906205A

US3906205A - Electrical fuel control system for internal combustion engines

Info

Publication number: US3906205A
Application number: US444170A
Authority: US
Inventors: Hiroshi Yoshida; Noriyoshi Ando; Kazuo Oishi
Original assignee: NipponDenso Co Ltd
Current assignee: Denso Corp
Priority date: 1970-03-20
Filing date: 1974-02-20
Publication date: 1975-09-16
Anticipated expiration: 1992-09-16

Abstract

An electrical control system with a plurality of sensors, shifted code setting circuits, selecting means, adders, memories and a command signal generator causing output signals of the sensors to be respectively binary-coded, shifted by the shifted code setting circuits and selected in accordance with the output signals of the sensor corresponding thereto in the manner previously programmed, for developing respective output signals which are added in a time-sharing manner controlled by the command signal generator to obtain an engine control signal to secure the optimum engine condition.

Description

United States Patent Yoshida et al.

ELECTRICAL FUEL CONTROL SYSTEM FOR INTERNAL COMBUSTION ENGINES Inventors: Hiroshi Yoshida; Noriyoshi Ando;

Kazuo Oishi, all of Kariya, Japan [73] Assignee: Nippondenso Co., Ltd., Kariya,

Japan Notice: The portion of the term of this patent subsequent to June 1 l, 1991, has been disclaimed.

[22] Filed: Feb. 20, 1974 21 Appl. No.: 444,170

Related US. Application Data Continuation-impart of Scr. No. 327,603, Jan. 26, 1973, Pat. No. 3,816,717, which is a continuation of Ser. No. 126,830, March 22, 1971, abandoned.

1*Sept. 16, 1975 [56] References Cited UNITED STATES PATENTS 3,749,070 7/1973 Oishi 123/32 EA 3,756,204 /1973 Suda 123/32 EA 3,796,197 3/1974 Locher et a1. 123/32 EA 3,811,037 5/1974 Kitano 235/150.21

OTHER PUBLICATIONS Williams: Electronic Fuel Injection Reduces Automo tive Pollution, Electronics, Sept. 1972, Vol. 45, No. 19, pp. 121425.

Primary Examiner-Felix D. Gruber Attorney, Agent, or F irm-Cushman, Darby & Cushman [5 7] ABSTRACT An electrical control system with a plurality of sensors, shifted code setting circuits, selecting means, adders, memories and a command signal generator causing output signals of the sensors to be respectively binary-coded, shifted by the shifted code setting circuits and selected in accordance with the output signals of the sensor corresponding thereto in the manner previously programmed. for developing respective output signals which are added in a time-sharing manner controlled by the command signal generator to obtain an engine control signal to secure the optimum engine condition.

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Claims

1. A control system for an internal combustion engine comprising: first sensor means for producing a first digital signal responsive to a first parameter of the engine condition, first discriminating means, connected in circuit with said first sensor for detecting one of a plurality of predetermined first parameter ranges which includes said first parameter as represented by said first digital signal, and producing a number of output signals as determined by said detected first parameter range; second sensor means for producing a second digital signal responsive to a second parameter of the engine condition, second discriminating means connected in circuit with said second sensor for detecting one of a plurality of predetermined second parameter ranges which includes said second parameter as represented by said second digital signal, and producing a number of output signals as determined by said second parameter ranges; shifted code setting circuit means for shifting an input digital code signal applied thereto, selecting means connected to said first and second discriminating means for selecting an input signal applied thereto in accordance with the output signals of said first and second discriminating means, first circuit means connected to said first and second sensor means and including said shifted code setting circuit means and said selecting means for producing coded digital signals in codes which are obtained by subjecting said first and second digital signals to shifting and selecting operations by said shifted code setting circuit means and said selecting means in accordance with the output signals of said first and second discriminating means, second circuit means, connected to said first circuit means and including an adder and a memory, for producing a digital control signal by adding the coded digital signal outputs of said first circuit means; command signal generating means, connected to said second circuit means, for producing command signals to control a setreset operation of said memory in the time sharing manner, third circuit means connected to said second circuit means for producing a drive signal in accordance with said digital control signal of said second circuit means; and electrically actuating means connected to said third circuit for operating in accordance with the drive signal of said third circuit means.

2. A control system for an internal combustion engine according to claim 1, wherein said first discriminating means comprises a plurality of discriminators connected to said command signal generating means for determining whether the first digital signal of said first snesor means is greater or smaller than a predetermined value in response to said command signals.

3. A control system for an internal combustion engine according to claim 1, wherein said selecting means of said first circuit means comprises a plurality of logical elements connected to said first and second discriminating means and a plurality of gate means connected to said shifted code setting circuit means of said first circuit means.

4. A control system for an internal combustion engine according to claim 1, wherein said first and second digital signals of said first and second sensor means are produced in a binary code of a predetermined number of places.

5. A control system for an internal combustion engine according to claim 4, wherein said shifted code setting circuit means produces digital signals in binary codes which indicate respectively numbers represented by binary codes oBtained by shifting said binary code of one of said first digital signal and second digital signal to the right successively by one place each shift.

6. A control system for an internal combustion engine according to claim 1, wherein said command signal generating means comprises a clock pulse generator, a flip-flop circuit connected to said clock pulse generator for dividing the time cycle of the clock pulse of said clock pulse generator, and logical circuit means connected to said flip-flop circuit.

7. A control system according to claim 1, wherein said third circuit means comprises: a memory circuit connected in circuit with said second circuit means for retaining said digital control signal of said second circuit means; an angular sensor for periodically producing pulses in accordance with rotations of the engine a timing sensor for producing a timing pulse responsive to a predetermined position each cycle of each cylinder; a counter for counting pulses of said angular sensor transmitted thereto and producing an output digital signal of binary code corresponding to the count a comparator for producing said drive signal upon coincidence of said digital signal of said memory circuit and that of said counter; a distributor comprising means responsive to said timing pulse for permitting said pulses of said angular sensor being transmitted therethrough to said counter.

8. A control system for an internal combustion engine according to claim 7, wherein said first parameter sensed by said first sensor means is intake manifold vacuum, said second parameter sensed by said second sensor means is speed of the engine and said electrically actuating means is an ignition system.

9. A control system for an internal combustion engine according to claim 1, wherein said third circuit means comprises; a memory circuit connected in circuit with said second circuit means for retaining said digital control signal of said second circuit means; a clock pulse generator for producing clock pulses with a predetermined frequency; means for producing a timing pulse which determines the starting of fuel injection during each cycle for each cylinder; a counter for counting said clock pulses transmitted thereto and producing an output digital signal in a binary code corresponding to the count; a comparator for producing an output signal for ending the operation of said electrically actuating means under coincidence of the digital signal retained in said memory and that of said counter, and a distributor including means responsive to said timing pulse for starting and continuing operation of said electrically actuating means and simultaneously permitting said clock pulses being transmitted to said counter from said clock pulse generator to pass therethrough and means responsive to an output signal of said comparator for ending the operation of said electrically actuating means and simultaneously preventing thereafter said clock pulse from being transmitted to said counter.

10. A control system according to claim 9, wherein said first parameter sensed by said first sensor means is intake manifold, said second parameter sensed by said second sensor means is the acceleration of the engine and said electrically actuating means is an electromagnetic valve for injecting fuel into the engine.

11. A control system according to claim 1, wherein said first sensor means comprises vacuum sensor means for producing a signal responsive to the intake manifold vacuum, said second sensor means comprises speed sensor means for producing a signal responsive to the speed of the engine, said electrically actuating means comprises an electromagnetic valve for injecting fuel into the engine and an ignition system for producing an ignition spark of the engine, and said third circuit means comprises injection circuit means having first selector switch means for energizing said electromagnetic vaLve and ignition circuit means having second selector switch means for energizing said ingition system; said control system further comprising selection signal generating means connected to said first and second switch means for controlling the transmission of said digital control signal of said second circuit means to said injection circuit means and to said ignition circuit means.