Patent US4724808A successfully refreshed from Google Patents.
US4724808A
Expired / Lapsed
US
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Idle revolution control device for internal combustion engine
Assignee: Mitsubishi Electric Corp
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Filing: 1987-05-08
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Granted: 1988-02-16
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Expires: 2007-05-08
Abstract
Abstract An idle revolution control device includes a water temperature sensor, a filter means and a control means which is constituted with a central processing unit and an interface connecting the water temperature sensor and the central processing unit. The filter means functions to provide a time constant which provide a high response speed for a temperature variation toward a high temperature side and a low response speed for a temperature variation toward a low temperature side and to pass an output signal of the water temperature sensor with such time constant a predetermined time after an engine starts.
Inventors
- 👤 Youichi Kadota
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:01
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/14; F02D41/16; F02D41/04; F02D41/06; F02D41/068; F02D31/00; F02D31/001; F02D31/002; F02D31/003; F02D31/005; F02D41/08
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
127 words
An idle revolution control device for an internal combustion engine comprising a water temperature sensor for detecting temperature of an engine coolant to provide an electric signal indicative of the temperature, a filter means connected to an output of said water temperature sensor, said filter means having a filter function for passing said output signal of said water temperature sensor a predetermined time after the engine starts, with time constants providing a high response speed for a temperature variation toward a high temperature side and a low response speed for a temperature variation toward a low temperature side, and a control means responsive to an output signal of said filter means for controlling an idling engine revolution to a desired revolution number for a detected water temperature.
Claim 2
Dependent Claim
127 words
An idle revolution control device for an internal combustion engine comprising a water temperature sensor for detecting temperature of an engine coolant to provide an electric signal indicative of the temperature, a filter means connected to an output of said water temperature sensor, said filter means having a filter function for passing said output signal of said water temperature sensor a predetermined time after the engine starts, with time constants providing a high response speed for a temperature variation toward a high temperature side and a low response speed for a temperature variation toward a low temperature side, and a control means responsive to an output signal of said filter means for controlling an idling engine revolution to a desired revolution number for a detected water temperature.
Claim 3
Dependent Claim
18 words
The idle revolution control device as claimed in claim 1, wherein said water temperature sensor is a thermister.
Claim 4
Dependent Claim
42 words
The idle revolution control device as claimed in claim 2, wherein said control means includes a central processing unit and an interface connecting said thermister and said central processing unit and wherein said filter means is provided by said central processing unit.
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) | 1991-02-15 | 1991-08-17 | 1992-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-15 | 1995-08-17 | 1996-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-15 | 1999-08-17 | 2000-02-16 | $7700.00 | Window Closed / Lapsed |