Patent US4040408A successfully refreshed from Google Patents.
US4040408A
Expired / Lapsed
US
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System for reducing toxic components in the exhaust gas of an internal combustion engine
Assignee: Robert Bosch GmbH
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Filing: 1975-08-05
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Granted: 1977-08-09
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Expires: 1995-08-05
Abstract
Abstract A fuel supply and metering valve assembly used for fuel injection to an internal combustion engine includes a control pressure circuit which determines the restoring force on the movable valve member of the metering valve. The magnitude of the control pressure, and hence the fuel quantity metered out by the valve assembly, can be altered by intermittent actuation of a pressure relief valve whose duty cycle is controlled by an oxygen sensor located in the exhaust line of the engine. The oxygen sensor voltage is superimposed on a sawtooth voltage at the input of a control circuit which varies the duty cycle of the bypass valve. When the oxygen sensor is too cold to generate an output signal, the control circuit is provided with a temporary control signal supplied by a timing circuit until the oxygen sensor has reached its normal temperature and generates an output signal.
Inventors
- 👤 Bernd Kraus
- 👤 Otto Glockler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:41
CPC Classifications
F; F02; F02D; F02D35/00; F02D35/0015; F02D35/0046; F02D35/0092; F02M; F02M69/00; F02M69/16; F02M69/26
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
154 words
In an apparatus for reducing the concentration of toxic components in the exhaust gas of an internal combustion engine, which engine includes a fuel supply system, a fuel metering system, and a control pressure circuit for controlling said fuel metering system, said control pressure circuit including an electromagnetic valve, said apparatus including a regulating device for cyclic actuation of said electromagnetic valve, and an oxygen sensor located in the exhaust system of the engine and electrically connected to said regulating device, the improvement comprising: a timing circuit, connected to said regulating device, for supplying a time-dependent control signal to said regulator device, said timing circuit including: i. a threshold switch for receiving input signals and for generating an output signal; ii. a logic gate, one of whose inputs is connected to the output of said threshold switch; and iii. a timer element, whose trigger input is connected to the output of said logic gate.
Claim 2
Dependent Claim
154 words
In an apparatus for reducing the concentration of toxic components in the exhaust gas of an internal combustion engine, which engine includes a fuel supply system, a fuel metering system, and a control pressure circuit for controlling said fuel metering system, said control pressure circuit including an electromagnetic valve, said apparatus including a regulating device for cyclic actuation of said electromagnetic valve, and an oxygen sensor located in the exhaust system of the engine and electrically connected to said regulating device, the improvement comprising: a timing circuit, connected to said regulating device, for supplying a time-dependent control signal to said regulator device, said timing circuit including: i. a threshold switch for receiving input signals and for generating an output signal; ii. a logic gate, one of whose inputs is connected to the output of said threshold switch; and iii. a timer element, whose trigger input is connected to the output of said logic gate.
Claim 3
Dependent Claim
21 words
An apparatus as defined in claim 1, wherein said regulating device includes circuitry which produces a sawtooth voltage having linear segments.
Claim 4
Dependent Claim
21 words
An apparatus as defined in claim 1, wherein said regulating device includes circuitry which produces a sawtooth voltage having exponential segments.
Claim 5
Dependent Claim
27 words
An apparatus as defined in claim 3, wherein said regulating device includes circuitry which produces a sawtooth voltage having exponential segments obeying an e-function (U=ke t ).
Claim 6
Dependent Claim
99 words
An apparatus as defined in claim 1, wherein said timing circuit further includes: iv. first voltage divider means, connected across a source of potential and including, in series, at least one fixed resistor and one variable resistor; v. second voltage divider means, connected across a source of potential and including, in series, at least one fixed resistor and one temperature-dependent resistor; and wherein said threshold switch is an operational amplifier whose non-inverting input is connected to the tap of said first voltage divider means and whose inverting input is connected to the tap of said second voltage divider means.
Claim 7
Dependent Claim
65 words
An apparatus as defined in claim 5, wherein said timing circuit further includes: vi. third voltage divider means, connected across a source of potential and including at least two resistors in series; and vii. transistor means, the emitter of which is connected to the tap of said third voltage divider means and the base of which is connected to the output of said timer element.
Claim 8
Dependent Claim
26 words
An apparatus as defined in claim 6, wherein said third voltage divider means includes a temperature-dependent resistor so located as to be responsive to engine temperature.
Claim 9
Dependent Claim
161 words
In an apparatus for reducing the concentration of toxic components in the exhaust gas of an internal combustion engine, which engine includes a fuel supply system, a fuel metering system, and a control pressure circuit for controlling said fuel metering system, said control pressure circuit including an electromagnetic valve, said apparatus including a regulating device for cyclic actuation of said electromagnetic valve, and an oxygen sensor located in the exhaust system of the engine and electrically connected to said regulating device, the improvement comprising: a timing circuit, connected to said regulating device, for supplying a time-dependent control signal to said regulator device, said timing circuit including: i. temperature sensor means responsive to the engine temperature; ii. switch means responsive to the output of said temperature sensor means; iii. a logic gate, one of whose inputs is connected to the output of said switch means; and iv. a timer element whose trigger input is connected to the output of said logic gate.
Claim 10
Dependent Claim
161 words
In an apparatus for reducing the concentration of toxic components in the exhaust gas of an internal combustion engine, which engine includes a fuel supply system, a fuel metering system, and a control pressure circuit for controlling said fuel metering system, said control pressure circuit including an electromagnetic valve, said apparatus including a regulating device for cyclic actuation of said electromagnetic valve, and an oxygen sensor located in the exhaust system of the engine and electrically connected to said regulating device, the improvement comprising: a timing circuit, connected to said regulating device, for supplying a time-dependent control signal to said regulator device, said timing circuit including: i. temperature sensor means responsive to the engine temperature; ii. switch means responsive to the output of said temperature sensor means; iii. a logic gate, one of whose inputs is connected to the output of said switch means; and iv. a timer element whose trigger input is connected to the output of said logic gate.
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) | 1980-08-08 | 1981-02-07 | 1981-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-08 | 1985-02-07 | 1985-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-08 | 1989-02-07 | 1989-08-09 | $7700.00 | Window Closed / Lapsed |