US3623461A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Controlled fuel injection arrangement for internal combustion engines
Assignee: Robert Bosch GmbH
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Filing: 1969-11-03
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Granted: 1971-11-30
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Expires: 1989-11-03
Abstract
Abstract A fuel injection control arrangement for establishing the opening duration of electromagnetically actuated injection valves in internal combustion engines. A control circuit generates the control voltage for varying the duration of pulses emitted by a monostable multivibrator which is actuated by a cam-operated switch driven from the crankshaft of the engine. The control voltage has a periodically varying waveform timed with respect to the pulses realized from the monostable multivibrator. Switching transistors within the control circuit are actuated upon expiration of a predetermined time delay after the terminations of the pulses from the multivibrator. One of the switching transistors is driven into saturation for generating a first time delay, and is subsequently operated in the nonsaturated region for generating a subsequent second time delay through which the predetermined opening duration of the valve is realized.
Inventors
- 👤 Friedrich Rabus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 02:49
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/30; F02D41/32
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
322 words
A controlled injection arrangement for an internal combustion engine comprising, in combination, at least one electromagnetically actuated valve; monostable multivibrator means with input transistor and output transistor for generating pulses applied to said valve to open said valve for a time interval determined by the duration of said pulses; control voltage generating means connected to said monostable multivibrator means for generating a voltage signal to vary the duration of said pulses as a function of the rotational speed of said engine, said voltage signal having a periodically varying waveform timed relative to said pulses; at least two switching transistors within said control voltage generating means and being actuated upon expiration of a predetermined time delay after the ends of said pulses; a first capacitor connected between the base of a first one of said switching transistors and the collector of said input transistor; a series combination of a second capacitor and a resistor connected between a second one of said switching transistors and said first one of the switching transistors, said second one of the switching transistors being driven into saturation for generating a first time delay and being driven into nonsaturated region for generating a subsequent second time delay, said first time delay being produced by the discharging of said second capacitor with a first time constant to a first predetermined voltage limit and said second time delay being produced by the charging of said second capacitor with a second time constant to a second predetermined voltage limit; a source of voltage; and a resistance voltage divider connected across said source of voltage for providing the first and second voltage limits of said capacitor, said resistance voltage divider having two taps, one of said taps being connected to the collector of said second one of the switching transistors, the other one of said taps being connected to the collector of said first one of the switching transistors through said second capacitor.
Claim 2
Dependent Claim
322 words
A controlled injection arrangement for an internal combustion engine comprising, in combination, at least one electromagnetically actuated valve; monostable multivibrator means with input transistor and output transistor for generating pulses applied to said valve to open said valve for a time interval determined by the duration of said pulses; control voltage generating means connected to said monostable multivibrator means for generating a voltage signal to vary the duration of said pulses as a function of the rotational speed of said engine, said voltage signal having a periodically varying waveform timed relative to said pulses; at least two switching transistors within said control voltage generating means and being actuated upon expiration of a predetermined time delay after the ends of said pulses; a first capacitor connected between the base of a first one of said switching transistors and the collector of said input transistor; a series combination of a second capacitor and a resistor connected between a second one of said switching transistors and said first one of the switching transistors, said second one of the switching transistors being driven into saturation for generating a first time delay and being driven into nonsaturated region for generating a subsequent second time delay, said first time delay being produced by the discharging of said second capacitor with a first time constant to a first predetermined voltage limit and said second time delay being produced by the charging of said second capacitor with a second time constant to a second predetermined voltage limit; a source of voltage; and a resistance voltage divider connected across said source of voltage for providing the first and second voltage limits of said capacitor, said resistance voltage divider having two taps, one of said taps being connected to the collector of said second one of the switching transistors, the other one of said taps being connected to the collector of said first one of the switching transistors through said second capacitor.
Claim 3
Dependent Claim
21 words
The controlled injection arrangement as defined in claim 1 incluDing diode means connected between said other tap and said second capacitor.
Claim 4
Dependent Claim
29 words
The controlled injection arrangement as defined in claim 2 including coupling resistor means connected between said diode means and the base of said second one of the switching transistors.
Claim 5
Dependent Claim
46 words
The controlled injection arrangement as defined in claim 3 wherein the resistance values of the different sections of said voltage divider are such that the collector current of said second one of the switching transistors has negligible effect upon the voltage relationships of said voltage divider.
Claim 6
Dependent Claim
217 words
A controlled injection arrangement for an internal combustion engine comprising, in combination, at least one electromagnetically actuated valve; monostable multivibrator means with input transistor and output transistor for generating pulses applied to said valve to open said valve for a time interval determined by the duration of said pulses; control-voltage-generating means connected to said monostable multivibrator means for generating a voltage signal to vary the duration of said pulses as a function of the rotational speed of said engine, said voltage signal having a periodically varying waveform timed relative to said pulses; at least two switching transistors within said control-voltage-generating means and being actuated upon expiration of a predetermined time delay after the ends of said pulses; a first capacitor connected between the base of a first one of said switching transistors and the collector of said input transistor; a series combination of a second capacitor and a resistor connected between a second one of said switching transistors and said first one of the switching transistors, said second one of the switching transistors being driven into saturation for generating a first time delay and being driven into nonsaturated region for generating a subsequent second time delay; and voltage divider means connected to the emitter of said second one of the switching transistors for limiting said voltage signal.
Claim 7
Dependent Claim
217 words
A controlled injection arrangement for an internal combustion engine comprising, in combination, at least one electromagnetically actuated valve; monostable multivibrator means with input transistor and output transistor for generating pulses applied to said valve to open said valve for a time interval determined by the duration of said pulses; control-voltage-generating means connected to said monostable multivibrator means for generating a voltage signal to vary the duration of said pulses as a function of the rotational speed of said engine, said voltage signal having a periodically varying waveform timed relative to said pulses; at least two switching transistors within said control-voltage-generating means and being actuated upon expiration of a predetermined time delay after the ends of said pulses; a first capacitor connected between the base of a first one of said switching transistors and the collector of said input transistor; a series combination of a second capacitor and a resistor connected between a second one of said switching transistors and said first one of the switching transistors, said second one of the switching transistors being driven into saturation for generating a first time delay and being driven into nonsaturated region for generating a subsequent second time delay; and voltage divider means connected to the emitter of said second one of the switching transistors for limiting said voltage signal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-29 | 1975-05-31 | 1975-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-29 | 1979-05-31 | 1979-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-29 | 1983-05-31 | 1983-11-30 | $7700.00 | Window Closed / Lapsed |