US5133310A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Intake and exhaust control apparatus for internal combustion engines
Assignee: Mazda Motor Corp
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Filing: 1990-12-18
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Granted: 1992-07-28
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Expires: 2010-12-18
Abstract
Abstract An intake-exhaust control system includes a mechanism for changing timings at which the open periods of intake and/or exhaust valves overlap. A control unit cooperates with the valve timing changing mechanism to cause it to change the timing stepwise so as to vary the valve overlap in time, or in degrees, in a plurality of steps according to engine operating conditions, such as engine speed and engine load. The valve overlap, when the engine operates under medium or moderate engine speeds, is varied so as to be larger or longer under medium engine loads than under higher or heavier and lower or lighter engine loads.
Inventors
- 👤 Mitsuo Hitomi
- 👤 Junsou Sasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:25
CPC Classifications
F; F02; F02D; F02D13/00; F02D13/02; F02D13/0203; F02D13/0215; F02D13/0219; F01; F01L; F01L1/00; F01L1/34; F01L1/344; F01L1/34403; F01L1/34406; F02D13/0242; F02D13/0249; F02D13/0261; F01L1/02; F01L1/04; F01L1/047; F01L2001/0475; F01L2201/00; F02D41/00; F02D41/0002; F02D2041/001; F02F; F02F7/00; F02F7/006; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
116 words
An intake and exhaust control system for changing a valve overlap, in degrees, of an internal combustion engine having intake and exhaust valves, comprising: . timing means for changing a valve operation timing of at least one of the intake and exhaust valves of the engine; monitoring means for monitoring an engine speed and an engine load and generating signals representative of said engine speed and said engine load; and control means responsive to said signals for causing said timing means to change said valve operation timing so as to vary the valve overlap for medium engine speeds so that the valve overlap is larger under medium engine loads than under lower and higher engine loads.
Claim 2
Dependent Claim
116 words
An intake and exhaust control system for changing a valve overlap, in degrees, of an internal combustion engine having intake and exhaust valves, comprising: . timing means for changing a valve operation timing of at least one of the intake and exhaust valves of the engine; monitoring means for monitoring an engine speed and an engine load and generating signals representative of said engine speed and said engine load; and control means responsive to said signals for causing said timing means to change said valve operation timing so as to vary the valve overlap for medium engine speeds so that the valve overlap is larger under medium engine loads than under lower and higher engine loads.
Claim 3
Dependent Claim
48 words
An intake and exhaust control system as recited in claim 1, wherein said control means causes said timing means to change said valve operation timing so as to make the valve overlap small independently of engine loads when the engine operates in a range of lower engine speeds.
Claim 4
Dependent Claim
55 words
An intake and exhaust control system as recited in claim 2, wherein said control means causes said timing means to change said valve operation timing so as to make the valve overlap smaller under heavier engine loads than under medium and lighter engine loads when the engine operates in a range of higher engine speeds.
Claim 5
Dependent Claim
30 words
An intake and exhaust control system as recited in claim 2, wherein said timing means cooperates with the exhaust valve to change the valve operation timing of the exhaust valve.
Claim 6
Dependent Claim
30 words
An intake and exhaust control system as recited in claim 4, wherein said timing means advances a valve opening timing of the exhaust valve for making said valve overlap larger.
Claim 7
Dependent Claim
30 words
An intake and exhaust control system as recited in claim 2, wherein said timing means cooperates with the intake valve to change the valve operation timing of the intake valve.
Claim 8
Dependent Claim
30 words
An intake and exhaust control system as recited in claim 6, wherein said timing means retards a valve closing timing of the intake valve for making said valve overlap larger.
Claim 9
Dependent Claim
110 words
An intake and exhaust control system for changing a valve overlap, in degrees, of an internal combustion engine having intake and exhaust valves, comprising: timing means for changing a valve operation timing of at least one of the intake and exhaust valves of the engine; monitoring means for monitoring engine speeds and engine loads and providing signals representative of engine operating speeds and engine operating loads; and control means responsive to said signals for causing said timing means to change said valve operation timing so as to make the valve overlap larger at middle engine operating loads than at high and low engine operating loads for a particular engine speed.
Claim 10
Dependent Claim
110 words
An intake and exhaust control system for changing a valve overlap, in degrees, of an internal combustion engine having intake and exhaust valves, comprising: timing means for changing a valve operation timing of at least one of the intake and exhaust valves of the engine; monitoring means for monitoring engine speeds and engine loads and providing signals representative of engine operating speeds and engine operating loads; and control means responsive to said signals for causing said timing means to change said valve operation timing so as to make the valve overlap larger at middle engine operating loads than at high and low engine operating loads for a particular engine speed.
Claim 11
Dependent Claim
25 words
An intake and exhaust control system as recited in claim 8, wherein said control means causes said timing means to change the valve overlap stepwise.
Claim 12
Dependent Claim
44 words
An intake and exhaust control system as recited in claim 9, wherein said control means causes said timing means to change said valve operation timing linearly with an increase in engine speed so as to vary the valve overlap in a plurality of steps.
Claim 13
Dependent Claim
47 words
An intake and exhaust control system as recited in claim 9, wherein said control means causes said timing means to change said valve operation timing in three steps with an increase in engine speed so as to vary the valve overlap in small, medium and large steps.
Claim 14
Dependent Claim
35 words
An intake and exhaust control system as recited in claim 11, wherein said timing means cooperates with both the intake and exhaust valves to change said valve operation timings of the intake and exhaust valves.
Claim 15
Dependent Claim
30 words
An intake and exhaust control system as recited in claim 12, wherein said timing means retards a valve opening timing of the intake valve, thereby making the valve overlap small.
Claim 16
Dependent Claim
30 words
An intake and exhaust control system as recited in claim 12, wherein said timing means retards a valve closing timing of the exhaust valve, thereby making the valve overlap large.
Claim 17
Dependent Claim
30 words
An intake and exhaust control system as recited in claim 12, wherein said timing means advances a valve opening timing of the intake valve, thereby making the valve overlap large.
Claim 18
Dependent Claim
30 words
An intake and exhaust control system as recited in claim 12, wherein said timing means advances a valve closing timing of the exhaust valve, thereby making the valve overlap small.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-07-28 | 1996-01-27 | 1996-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-07-28 | 2000-01-27 | 2000-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-07-28 | 2004-01-27 | 2004-07-28 | $7700.00 | Window Closed / Lapsed |