US4649485A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for controlling continuously variable transmission
Assignee: Toyota Motor Corp
•
Filing: 1984-07-10
•
Granted: 1987-03-10
•
Expires: 2004-07-10
Abstract
Abstract A continuously variable transmission (CVT) is controlled such that an actual engine speed Ne is equalized to a desired engine speed Ne'. Defining Nc as a positive constant, the speed ratio e of the CVT is substantially fixed during a period of time when the Ne changes from Ne<Ne'-Nc to Ne'-Nc≦Ne<Ne' and then changes to Ne≧Ne'. Ne'-Nc is defined as a temporarily desired engine speed during a period of time when the Ne changes from Ne≧Ne' to Ne'-Nc≦Ne<Ne' and then changes to Ne<Ne'-Nc. During the period of time the speed ratio of the CVT is changed such that the actual engine speed Ne is equalized to the temporarily desired engine speed Ne'-Nc.
Inventors
- 👤 Akinori Osanai
- 👤 Takao Niwa
- 👤 Takeshi Gono
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:35
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/66; F16H61/662; F16H61/66254; F16H61/66259
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
151 words
An apparatus for controlling a continuously variable transmission (CVT) wherein an actual engine speed Ne is equalized to a desired engine speed Ne', which is determined in accordance with at least one parameter said apparatus comprising: a means for providing a positive constant value to Nc, a means for substantially fixing the speed ratio of the CVT for a period of time starting when Ne changes from Ne<Ne'-Nc to Ne'-Nc≦Ne<Ne', and continuing until Ne≧Ne', a feedback control means for providing Ne'-Nc as a temporary desired engine value for a period of time starting when Ne changes from Ne≧Ne' to Ne'-Nc≦Ne<Ne', and continuing until Ne<Ne'-Nc, and a means for changing the speed ratio e of the CVT such that the actual engine speed Ne is equalized to the temporary engine speed Ne'-Nc during said period of time, wherein one of said parameters which determine the desired engine speed is the throttle position.
Claim 2
Independent Claim
151 words
An apparatus for controlling a continuously variable transmission (CVT) wherein an actual engine speed Ne is equalized to a desired engine speed Ne', which is determined in accordance with at least one parameter said apparatus comprising: a means for providing a positive constant value to Nc, a means for substantially fixing the speed ratio of the CVT for a period of time starting when Ne changes from Ne<Ne'-Nc to Ne'-Nc≦Ne<Ne', and continuing until Ne≧Ne', a feedback control means for providing Ne'-Nc as a temporary desired engine value for a period of time starting when Ne changes from Ne≧Ne' to Ne'-Nc≦Ne<Ne', and continuing until Ne<Ne'-Nc, and a means for changing the speed ratio e of the CVT such that the actual engine speed Ne is equalized to the temporary engine speed Ne'-Nc during said period of time, wherein one of said parameters which determine the desired engine speed is the throttle position.
Claim 3
Dependent Claim
68 words
An apparatus for controlling a continuously variable transmission (CVT) as defined in claim 1, wherein the speed change of the CVT is controlled such that when Ne≧Ne', a flag Fn is set, when Ne<Ne'-Nc, the flag Fn is reset, when Ne'-Nc≦Ne<Ne' and Fn=0 the speed ratio e is approximately fixed and when Ne'-Nc≦Ne<Ne' and Fn=1 Ne'-Nc is defined as a temporary desired engine speed Net' to provide Ne=Net'.
Claim 4
Dependent Claim
31 words
An apparatus for controlling a continuously variable transmission (CVT) as defined in claim 2, wherein the constant Nc is a function of a vehicle speed V and a throttle position θ.
Claim 5
Dependent Claim
16 words
An apparatus for controlling a continuously variable transmission (CVT) as defined in claim 3, wherein Net'=Ne'-Nc.
Claim 6
Independent Claim
114 words
A method for controlling a continuously variable transmission (CVT) wherein an actual engine speed Ne is equalized to a desired engine speed Ne', said method comprising the steps of: providing a positive constant value to Nc; substantially fixing the speed ratio of the CVT for a period of time startig when Ne changes from Ne<Ne'-Nc to Ne'-Nc≦Ne<Ne', and continuing until Ne≧Ne'; establishing Ne'-Nc as a temporary desired engine value for a period of time starting when Ne changes from Ne≧Ne' to Ne'-Nc≦Ne<Ne', and continuing until Ne<Ne'-Nc; changing the speed ratio e of the CVT such that the actual engine speed Ne is equalized to the temporary engine speed Ne'-Nc during said period of time.
Claim 7
Independent Claim
114 words
A method for controlling a continuously variable transmission (CVT) wherein an actual engine speed Ne is equalized to a desired engine speed Ne', said method comprising the steps of: providing a positive constant value to Nc; substantially fixing the speed ratio of the CVT for a period of time startig when Ne changes from Ne<Ne'-Nc to Ne'-Nc≦Ne<Ne', and continuing until Ne≧Ne'; establishing Ne'-Nc as a temporary desired engine value for a period of time starting when Ne changes from Ne≧Ne' to Ne'-Nc≦Ne<Ne', and continuing until Ne<Ne'-Nc; changing the speed ratio e of the CVT such that the actual engine speed Ne is equalized to the temporary engine speed Ne'-Nc during said period of time.
Claim 8
Dependent Claim
68 words
A method for controlling a continuously variable transmission (CVT) as defined in claim 5, wherein the speed change of the CVT is controlled such that when Ne≧Ne', a flag Fn is set, when Ne<Ne'-Nc, the flag Fn is reset, when Ne'-Nc≦Ne<Ne' and Fn=0 the speed ratio e is approximately fixed and when Ne'-Nc≦Ne<Ne' and Fn=1 Ne'-Nc is defined as a temporary desired engine speed Net' to provide Ne=Net'.
Claim 9
Dependent Claim
31 words
A method for controlling a continuously variable transmission (CVT) as defined in claim 6, wherein the constant Nc is a function of a vehicle speed V and a throttle position θ.
Claim 10
Dependent Claim
20 words
A method according to claim 7 for controlling a continuously variable transmission (CVT) as defined in claim 7, wherein Net'=Ne'-Nc.
References Cited (Backward Citations)
US4383456A
Cited
US4161894A
Cited
US4291594A
Cited
US4342298A
Cited
US4515041A
Cited
US4481844A
Cited
US4507986A
Cited
US4458318A
Cited
US4515040A
Cited
US4536171A
Cited
US4458560A
Cited
US4459878A
Cited
US4546673A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-03-09 | 1990-09-08 | 1991-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-09 | 1994-09-08 | 1995-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-09 | 1998-09-08 | 1999-03-10 | $7700.00 | Window Closed / Lapsed |