Patent US4461253A successfully refreshed from Google Patents.
US4461253A
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Method of controlling the idle rotational speed of an internal combustion engine
Assignee: Toyota Motor Corp
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Filing: 1982-09-15
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Granted: 1984-07-24
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Expires: 2002-09-15
Abstract
Abstract The idle air flow to an engine is increased or decreased in response to a control signal which is produced by comparing actual engine speed with a desired idle speed. Whether the above increase or decrease operation is continuously repeated more than a certain times is discriminated. If it is repeated more than the certain times, whether the variation of the engine speed during the above continuous increase or decrease operation is less than a predetermined value is discriminated. When the engine-speed variation during the above increase or decrease operation is less than the predetermined value, the idle speed control operation is inhibited from being executed.
Inventors
- 👤 Mamoru Kobashi
- 👤 Hiroshi Ito
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:33
CPC Classifications
F; F02; F02D; F02D31/00; F02D31/001; F02D31/002; F02D31/003; F02D31/005; F02D11/00; F02D11/06; F02D11/10; F02D2011/101; F02D2011/102
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
208 words
A method of controlling the idle rotational speed of an internal combustion engine including the steps of: detecting the rotational speed of the engine to produce an engine-speed signal which is determined depending upon the detected engine-speed; comparing said engine-speed signal with a reference signal which represents a desired idle speed of the engine to produce a control signal in accordance with the above comparison; increasing or decreasing the idle air flow to the engine in response to said control signal; and repeating the above sequence of steps so as to reduce the difference between said detected engine speed and said desired idle speed, wherein the improvement comprises the steps of: discriminating whether or not the above increasing step of idle air flow is continuously repeated more than a predetermined number of times or the above decreasing step of idle air flow is continuously repeated more than a predetermined number of times; if repeated more than the predetermined number of times, discriminating whether or not the variation of the engine speed during said repeated increasing or decreasing steps is less than a predetermined value; and if the engine-speed variation is less than the predetermined value, inhibiting the above control operation of the idle rotational speed from being executed.
Claim 2
Independent Claim
208 words
A method of controlling the idle rotational speed of an internal combustion engine including the steps of: detecting the rotational speed of the engine to produce an engine-speed signal which is determined depending upon the detected engine-speed; comparing said engine-speed signal with a reference signal which represents a desired idle speed of the engine to produce a control signal in accordance with the above comparison; increasing or decreasing the idle air flow to the engine in response to said control signal; and repeating the above sequence of steps so as to reduce the difference between said detected engine speed and said desired idle speed, wherein the improvement comprises the steps of: discriminating whether or not the above increasing step of idle air flow is continuously repeated more than a predetermined number of times or the above decreasing step of idle air flow is continuously repeated more than a predetermined number of times; if repeated more than the predetermined number of times, discriminating whether or not the variation of the engine speed during said repeated increasing or decreasing steps is less than a predetermined value; and if the engine-speed variation is less than the predetermined value, inhibiting the above control operation of the idle rotational speed from being executed.
Claim 3
Dependent Claim
55 words
A method as claimed in claim 1, wherein said rotational speed detecting step includes the steps of: detecting the actual rotational speed of the engine; and calculating the average of the detected actual rotational speed to produce an engine-speed signal which indicates the average of the detected engine speed for a predetermined period of time.
Claim 4
Dependent Claim
48 words
A method as claimed in claim 1, wherein said variation discriminating step includes a step of discriminating whether or not the difference between an engine speed at a time when the repeating increment or decrement steps were initiated and a present engine-speed is less than a predetermined value.
Claim 5
Dependent Claim
60 words
A method as claimed in claim 1, wherein said increasing or decreasing step includes a step of increasing or decreasing, in response to said control signal, the sectional area of a bypass passage which communicates the intake passage at a position located upstream of the throttle valve with the intake passage at a position located downstream of the throttle valve.
Claim 6
Dependent Claim
31 words
A method as claimed in claim 1, wherein said increasing or decreasing step includes a step of changing, in response to said control signal, the closed position of the throttle valve.
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) | 1987-07-24 | 1988-01-23 | 1988-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-24 | 1992-01-23 | 1992-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-24 | 1996-01-23 | 1996-07-24 | $7700.00 | Window Closed / Lapsed |