FUEL INJECTION SYSTEM FOR INTERNAL COMBUSTION ENGINE

• US 3,734,067 A
• Filed: 12/17/1970
• Issued: 05/22/1973
• Est. Priority Date: 01/22/1970
• Status: Expired due to Term

• Current Assignee: Dieter Eichler, Hermann Schmid, Otto Glockler
• Original Assignee: Dieter Eichler, Hermann Schmid, Otto Glockler
• Inventors: Glockler, Otto, Schmid, Hermann, Eichler, Dieter
• Primary Examiner(s): Goodridge, Laurence M.
• Assistant Examiner(s): Flint, Cort
• Application Number:
  US05/099,139
• Time in Patent Office: 887 Days
• Field of Search: 123/32EA
• US Class Current: 123/484
• CPC Class Codes: F02D 41/061 the corrections being time dependent

Abstract

To extend the time of opening of fuel injection valves during starting, a timing circuit, having a time constant preferably between 5 and 30 seconds, and desirably about 25 seconds, is connected to the electronic control circuit controlling the opening times of the fuel injection valves. The timing circuit provides a decreasing signal to extend the time during which the injection valves are open from the time the starter switch is operated. Preferably, the fuel injection system includes a pulse duration multiplier circuit, having a multiplication factor varying between 1 and 5, and the timing circuit affects the multiplication factor.

Claims

1. Fuel injection system for internal combustion engines having means controlling the injection of fuel comprising at least one electrically operated fuel injection valve;

electrical means synchronized with the rotation of the engine generating electrical pulses, connected to said valve, to open the valve;

control means including means generating a base pulse (In) having a determined pulse length and a multiplying stage generating an extension pulse (Iv), said extension pulse being longer than said base pulse length by a multiplying factor (f) of from 1 to 5 and controlled by an operating parameter of the engine connected to said electrical means and controlling the length of said pulses;

an electrical starting control means including a starter switch;

a timing circuit having a fixed predetermined timing period regardless of engine temperature and connected to said starting control means (30) to start the timing period upon actuation of said starter switch and connected in circuit with said control means to affect the multiplying factor of said multiplying sate and to increase the multiplying factor during said fixed predetermined timing period upon starting to thereby prolong the pulses upon starting of the engine.

2. System according to claim 1, wherein the timing circuit has a timing period in the order of from about 5-30 seconds.

3. System according to claim 1, wherein the timing circuit has a timing period in the order of about 20-25 seconds.

4. System according to claim 3, wherein the starter switch is interconnected with said timing circuit to apply a voltage to said circuit during operation of the starter switch.

5. System according to claim 1, wherein said timing circuit provides a variable control signal to said control means to continuously reduce the duration of the extension pulses generated by the multiplication stage from a prolonged period immediately upon starting, until the pulse duration is determined solely by said operating parameters when said predetermined period has elapsed.

6. System according to claim 1, wherein said timing circuit comprises a transistor (Tr);

means holding said transistor in blocked condition;

means (R3) interconnecting the starter switch wiTh the base of the transistor; and

a capacitor (C) connected in the transistor circuit between the collector and another electrode thereof.

7. System according to claim 1, wherein a source of supply (33, 52) is provided;

said timing circuit comprises first and second transistors (85,

     86) of similar conductivity type;

a resistance (87) interconnecting the emitter of one transistor (85) to one supply source terminal (52) and a resistance (93) interconnecting the collector of said one transistor (85) to the other supply source terminal (33);

a base resistance (88) connected from the base parallel to the emitter resistance (87) to the respective terminal of the supply source and holding said one of said transistors (85) in normally blocked state;

means (94,

     95) interconnecting the base of said normally blocked transistor (85) to the starter switch (96); and

a capacitor (89) connected with one terminal to said switch-transistor interconnection means, the other terminal of said capacitor being connected to the collector electrode of the other transistor (86).

8. System according to claim 7, wherein said multiplying stage has a charging transistor (61) and a capacitor (60) having one terminal connected, in series, with the emitter-collector path of the charging transistor (61);

a discharge transistor (62) connected to the other terminal of the capacitor (60); and

means interconnecting the collector of said second transistor (86) of the timing circuit (30) to the base of the charging transistor (61) to increase the charging current to said charging transistor, and thus the pulse length of said extension pulse, upon conduction of said second transistor (86), as determined by the state of conduction of said first transistor (85).

9. System according to claim 1, wherein said timing circuit comprises a capacitor (89);

a constant current supply circuit, and switching means being connected to affect a charge on the capacitor (89) upon closing of the starter switch (96); and

means applying a current in dependence on the change of charge of said capacitor (89) to said multiplying stage and affecting the multiplying factor thereof.

10. System according to claim 1, wherein said control means comprises a first capacitor (60);

means (61,

     62) controlling the charging rate of said first capacitor; and

said timing circuit (30) includes switching means (85, 86;

Tr) and a further capacitor (89;

C), said switching means interconnecting said further capacitor with said first capacitor (60) to affect the change of charge on the total capacitance in circuit with said control means upon operation of said switching means as determined by operation of the starter switch (96).

11. System according to claim 10, wherein said switching means comprises at least one transistor connected to be normally blocked, and to become conductive upon operation of said starter switch (96);

said transistor being interconnected with said further capacitor (89) to provide a discharge path for said further capacitor (89) upon change of said transistor to conductive state, and to extend the time during which said means controlling the charge rate of said first capacitor (60) provides charging current.