Patent US3134832A successfully refreshed from Google Patents.
Patent US4148282A successfully refreshed from Google Patents.
US4148282A
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US
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Method and apparatus for cold starting fuel injected internal combustion engines
Assignee: Robert Bosch GmbH
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Filing: 1978-06-01
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Granted: 1979-04-10
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Expires: 1998-06-01
Abstract
Abstract A control circuit for a fuel-injected internal combustion engine provides a substitute program for generation of fuel injection control pulses during engine starts at low temperatures. The substitute injection control pulses are made dependent on the ambient or engine temperature in the sense that, the lower the temperature, the greater is the length of the injection pulses, i.e., the larger is the quantity of initially injected fuel. The length of the injection pulses also depends on the elapsed duration of the engine starting attempt in the sense of gradually reducing the injected fuel quantity as the unsuccessful engine cranking proceeds. A fully opened throttle during engine cranking signals a flooded engine condition and completely interrupts fuel injection.
Inventors
- 👤 Alfred Grassle
- 👤 Hans Schnurle
- 👤 Thomas Wilfert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:25
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/04; F02D41/06; F02D41/061; F02D41/062; F02D41/065
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
176 words
An apparatus for controlling fuel injection during cold starts of an internal combustion engine, said engine including a fuel injection system and means for producing a signal related to crankshaft rotation and a signal related to engine temperature, comprising: a first monostable multivibrator whose output engages said fuel injection system, for providing special fuel injection control pulses during cold starts; a first capacitor, connected to the input of said first multivibrator for controlling the period during which said first multivibrator resides in its unstable state; a second monostable multivibrator triggered by said first monostable multivibrator for providing two separate fuel injection pulses for each crankshaft revolution; a second capacitor for determining the unstable period of the second multivibrator, the charging of the first and second capacitors taking place by means of a temperature-dependent voltage; a discharge control circuit for each capacitor for controlling the discharge of the capacitors to thereby control the switching of the multivibrators; and a master control circuit, for receiving said signals related to crankshaft rotation and for controlling said discharge control circuit.
Claim 2
Independent Claim
176 words
An apparatus for controlling fuel injection during cold starts of an internal combustion engine, said engine including a fuel injection system and means for producing a signal related to crankshaft rotation and a signal related to engine temperature, comprising: a first monostable multivibrator whose output engages said fuel injection system, for providing special fuel injection control pulses during cold starts; a first capacitor, connected to the input of said first multivibrator for controlling the period during which said first multivibrator resides in its unstable state; a second monostable multivibrator triggered by said first monostable multivibrator for providing two separate fuel injection pulses for each crankshaft revolution; a second capacitor for determining the unstable period of the second multivibrator, the charging of the first and second capacitors taking place by means of a temperature-dependent voltage; a discharge control circuit for each capacitor for controlling the discharge of the capacitors to thereby control the switching of the multivibrators; and a master control circuit, for receiving said signals related to crankshaft rotation and for controlling said discharge control circuit.
Claim 3
Dependent Claim
35 words
An apparatus as defined by claim 1, wherein said master control circuit receives a temperature-dependent signal which is additionally made dependent on the duration of the cranking process, preferably on the number of crankshaft revolutions.
Claim 4
Dependent Claim
64 words
An apparatus as defined by claim 2, further comprising a triggering circuit which is provided with said signal related to crankshaft rotation, preferably an ignition signal, for triggering the switch-over of said first monostable multivibrator to its unstable state and also for integration within said master control circuit, the integrated potential of said signal defining a temperature-dependent control signal for said discharge control circuit.
Claim 5
Dependent Claim
92 words
An apparatus as defined by claim 3, further comprising a series subcircuit consisting of a resistor, a diode, a capacitor and a further resistor, said series subcircuit being connected between a signal input of said master control circuit and the ground conductor of said master control circuit and wherein said master control circuit further includes an integrating capacitor; whereby, when a trigger signal is supplied to said diode, said diode is thereby reversely biased and blocks so that said integrating capacitor sums up the triggering pulses provided to said master control circuit.
Claim 6
Dependent Claim
61 words
An apparatus as defined by claim 4, further comprising first and second transistors connected in Darlington configuration, said integrating capacitor being connected between the base and emitter of one of said Darlington transistors, the second one of said Darlington transistors providing the conductive path for a temperature-dependent signal whose magnitude also changes in dependence on the charge on said integrating capacitor.
Claim 7
Dependent Claim
55 words
An apparatus as defined by claim 5, wherein said integrating capacitor is connected to said discharge control circuit which provides a positive potential to a second diode in said master control circuit; whereby said discharge control circuit discharges said integrating capacitor at a predetermined time constant only during pauses in the cranking of the engine.
Claim 8
Dependent Claim
67 words
An apparatus according to claim 6, further comprising a triggering circuit including an RC member for differentiating said signal related to crankshaft rotation which signal is then used to trigger said first monostable multivibrator, said first monostable multivibrator including two transistors, the base of one of said two transistors being connected through a diode and a capacitor to said triggering circuit to receive said differentiated trigger pulse.
Claim 9
Dependent Claim
68 words
Apparatus as defined by claim 7, wherein the collector of said one transistor in said first monostable multivibrator is connected through a resistor to an output contact from which fuel injection pulses may be taken and is also connected through a diode to said second monostable multivibrator; whereby, when said first monostable multivibrator returns to its stable state a triggering pulse is fed to said second monostable multivibrator.
Claim 10
Dependent Claim
44 words
An apparatus as defined by claim 8, wherein said second monostable multivibrator includes a single transistor and a capacitor connected to the base of said single transistor; whereby the discharge of said capacitor determines the duration of the unstable state of said second multivibrator.
Claim 11
Dependent Claim
56 words
An apparatus according to claim 9, wherein said capacitors defining the unstable states of said first and second multivibrators can be discharged only via said discharge control circuit and wherein said discharge control circuit includes transistors forming a constant current source, the base of said transistors being connected with the output of said master control circuit.
Claim 12
Dependent Claim
49 words
An apparatus as defined by claim 10, wherein the emitters of said transistors in said discharge control circuit are connected through resistors to the positive supply of said circuit and wherein the collectors of said transistors are connected to said capacitors which determine the unstable state of said multivibrators.
Claim 13
Dependent Claim
44 words
An apparatus as defined by claim 11, wherein the transistors which define the duration of the unstable state of said first monostable multivibrator are connected by their collectors via resistors with a conductor which carries a positive potential during the cranking of the engine.
Claim 14
Dependent Claim
42 words
An apparatus as defined by claim 12, wherein said conductor carrying a positive potential during engine cranking is connected via a resistor and a diode to an output contact which provides a voltage for suppressing normal fuel injection pulses during engine cranking.
Claim 15
Dependent Claim
58 words
An apparatus as defined by claim 13, wherein the transistors in said first and second multivibrators which provide the start-up fuel injection pulses are provided at their bases with a potential during full throttle engine operation and while the engine is being cranked for preventing the switch-over of said first and second monostable multivibrators to the unstable state.
Claim 16
Dependent Claim
32 words
An apparatus as defined by claim 14, further comprising switch means associated with the throttle valve of the engine for grounding the base of said transistors in said first and second multivibrators.
Claim 17
Dependent Claim
65 words
An apparatus as defined by claim 1, further comprising a series subcircuit of a Zener diode and a resistor connected between the positive and the negative supplies of said apparatus, a point in said series subcircuit being connected via a further resistor to the junction of resistors lying in the charging circuit for said capacitors which are part of said monostable first and second multivibrators.
Claim 18
Dependent Claim
40 words
An apparatus as defined by claim 16, further comprising voltage divider means connected between said positive and negative voltage supplies of the apparatus, points of said voltage divider being connected to the emitters of said transistors in said discharge circuit.
Claim 19
Dependent Claim
59 words
An apparatus as defined by claim 17, further comprising a series connection of two resistors connected between the positive and negative supply lines of said apparatus, one of said resistors being adjustable, points of said series circuit being connected to said discharge control circuit for providing a temperature-independent charging voltage for said capacitors in said first and second multivibrators.
Claim 20
Dependent Claim
23 words
An apparatus as defined by claim 18, wherein said series circuit of resistors is connected to said series circuit containing a Zener diode.
Claim 21
Independent Claim
133 words
A method for controlling fuel injection from fuel injection valves during cold engine starts; comprising the steps of: disabling the supply of normal fuel injection control pulses to the fuel injection valves; generating an engine temperature dependent voltage, such that the voltage decreases for increasing engine temperature; generating trigger pulses synchronized with crankshaft rotation; connecting a timing device to the fuel injection valves; applying the trigger pulses to the timing device during which time the injection valves are controlled by the timing device; generating a control voltage based upon the temperature voltage and the trigger pulses for controlling the duration of the timing device control of the injection valves; and varying the magnitude of the control voltage as a function of the temperature voltage and the number of trigger pulses elapsed during cranking.
Claim 22
Independent Claim
133 words
A method for controlling fuel injection from fuel injection valves during cold engine starts; comprising the steps of: disabling the supply of normal fuel injection control pulses to the fuel injection valves; generating an engine temperature dependent voltage, such that the voltage decreases for increasing engine temperature; generating trigger pulses synchronized with crankshaft rotation; connecting a timing device to the fuel injection valves; applying the trigger pulses to the timing device during which time the injection valves are controlled by the timing device; generating a control voltage based upon the temperature voltage and the trigger pulses for controlling the duration of the timing device control of the injection valves; and varying the magnitude of the control voltage as a function of the temperature voltage and the number of trigger pulses elapsed during cranking.
Claim 23
Dependent Claim
24 words
The method as defined in claim 20, wherein a monostable multivibrator is connected to the fuel injection valves and serves as the timing device.
Claim 24
Independent Claim
175 words
An apparatus for controlling fuel injection during cold starts of an internal combustion engine, said engine including a fuel injection system and means for producing a signal related to crankshaft rotation and a signal related to engine temperature, comprising: a first timing device whose output engages said fuel injection system, for providing special fuel injection control pulses during cold starts; a first capacitor, connected to the input of said first timing device for controlling the timing constant of said first timing device; a second timing device actuated by said first timing device for providing two separate fuel injection pulses for each crankshaft revolution; a second capacitor for determining the timing constant of the second timing device, the charging of the first and second capacitors taking place by means of a temperature-dependent voltage; a discharge control circuit for each capacitor for controlling the discharge of the capacitors to thereby control the switching of the timing devices; and a master control circuit, for receiving said signals related to crankshaft rotation and for controlling said discharge control circuit.
Claim 25
Independent Claim
175 words
An apparatus for controlling fuel injection during cold starts of an internal combustion engine, said engine including a fuel injection system and means for producing a signal related to crankshaft rotation and a signal related to engine temperature, comprising: a first timing device whose output engages said fuel injection system, for providing special fuel injection control pulses during cold starts; a first capacitor, connected to the input of said first timing device for controlling the timing constant of said first timing device; a second timing device actuated by said first timing device for providing two separate fuel injection pulses for each crankshaft revolution; a second capacitor for determining the timing constant of the second timing device, the charging of the first and second capacitors taking place by means of a temperature-dependent voltage; a discharge control circuit for each capacitor for controlling the discharge of the capacitors to thereby control the switching of the timing devices; and a master control circuit, for receiving said signals related to crankshaft rotation and for controlling said discharge control circuit.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-04-09 | 1982-10-09 | 1983-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-09 | 1986-10-09 | 1987-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-09 | 1990-10-09 | 1991-04-10 | $7700.00 | Window Closed / Lapsed |