EP0136519A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Air-fuel ratio control apparatus for internal combustion engines
Assignee: Hitachi Ltd
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Filing: 1984-08-23
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Granted: —
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Expires: 2004-08-23
Abstract
Abstract A control apparatus Includes an air-fuel ratio sensor (7) for detecting an oxygen content over a wide range of operating conditions from a light load operation to a high load operation of an engine and the sensor (7) is utilized so as to establish the desired air-fuel ratio such that the air-fuel ratio (λ) becomes λ>1, λ=1 or λ<1, respectively, in the light, intermediate or high load operating region of the engine and the output of the air-fuel ratio sensor (7) is utilized so as to feedback control the air-fuel ratio over the wide range of operating conditions and thereby maintain the desired air-fuel ratio in each of the operating regions.
Inventors
- 👤 Yoshishige Oyama
- 👤 Mamoru Fujieda
- 👤 Teruo Yamauchi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 21:59
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/18; F02D41/14; F02D41/1438; F02D41/1477; F02D41/1479; F02D41/04; F02D41/1486
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
213 words
An air-fuel ratio control apparatus for internal combustion engines comprising: a sensor (2) for detecting an intake air flow to an engine; an engine rotational speed sensor (8); an air-fuel ratio sensor (7) for detecting an amount of oxygen over a wide range of operating conditions from a light load operation to a high load operation of said engine; a cooling water temperature sensor (6); throttle valve control means (4); fuel supply means (3); ignition means (9), and a control signal generating circuit (10) for receiving signals from said intake air flow sensor (2), said rotational speed sensor (8), said cooling water temperature sensor (6) and said air-fuel ratio sensor (7) to process said signals in accordance with a predetermined program and generate control signals for controlling said throttle valve control means (4), said fuel supply means (3) and said ignition means (9), whereby a desired air-fuel ratio is set in such a manner that an air-fuel ratio (λ) in a light-load, intermediate-load or high-load operating region of said engine becomes A > 1, λ = 1 or λ < 1, respectively, and an output of said air-fuel ratio sensor (7) is utilized to make a feedback control such that said desired air-fuel ratio is maintained in corresponding one of said operating regions.
Claim 2
Dependent Claim
213 words
An air-fuel ratio control apparatus for internal combustion engines comprising: a sensor (2) for detecting an intake air flow to an engine; an engine rotational speed sensor (8); an air-fuel ratio sensor (7) for detecting an amount of oxygen over a wide range of operating conditions from a light load operation to a high load operation of said engine; a cooling water temperature sensor (6); throttle valve control means (4); fuel supply means (3); ignition means (9), and a control signal generating circuit (10) for receiving signals from said intake air flow sensor (2), said rotational speed sensor (8), said cooling water temperature sensor (6) and said air-fuel ratio sensor (7) to process said signals in accordance with a predetermined program and generate control signals for controlling said throttle valve control means (4), said fuel supply means (3) and said ignition means (9), whereby a desired air-fuel ratio is set in such a manner that an air-fuel ratio (λ) in a light-load, intermediate-load or high-load operating region of said engine becomes A > 1, λ = 1 or λ < 1, respectively, and an output of said air-fuel ratio sensor (7) is utilized to make a feedback control such that said desired air-fuel ratio is maintained in corresponding one of said operating regions.
Claim 3
Dependent Claim
24 words
An apparatus according to claim 1, wherein said desired air-fuel ratio is corrected by utilizing an output from said cooling water temperature sensor (6).
Claim 4
Dependent Claim
43 words
An apparatus according to claim 1, further comprising a gear ratio sensor (20) for generating a signal corresponding to a gear ratio of a gear transmission whereby said desired air-fuel ratio is corrected by utilizing an output from said gear ratio sensor (20).
Claim 5
Dependent Claim
36 words
An apparatus according to claim 1, further comprising a temperature sensor (51) for detecting a temperature of an exhaust gas whereby said desired air-fuel ratio is corrected by utilizing an output from said temperature sensor (51).
Claim 6
Dependent Claim
42 words
An apparatus according to claim 1, wherein a torque characteristic of said engine is provided with a hysteresis characteristic (Hl, H2) with respect to the quantity of fuel supplied whereby said air-fuel ratio is changed smoothly in said air-fuel ratio feedback control.
Claim 7
Dependent Claim
44 words
An apparatus according to claim 1, wherein a change in the quantity of fuel supplied indicating an acceleration (A) of a vehicle equipped with said engine is utilized so as to change said air-fuel ratio smoothly in accordance with a weight of said vehicle.
Claim 8
Dependent Claim
38 words
An apparatus according to claim 1, further comprising means for storing a delay characteristic (lt) of said air-fuel ratio sensor (7) whereby said desired air-fuel ratio is corrected by utilizing said delay characteristic stored in said storage means.
Claim 9
Dependent Claim
33 words
An apparatus according to claim 1, wherein said desired air-fuel ratio is corrected by utilizing an error (e) of a detection output signal due to an aging of said air-fuel ratio sensor (7).
References Cited (Backward Citations)
No citation records indexed.
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