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EP0149013A2
Expired / Lapsed
EP
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Transmission control system including vehicle speed responsive orifice valve which modifies friction element engagement rate
Assignee: Nissan Motor Co Ltd
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Filing: 1984-10-05
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Granted: —
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Expires: 2004-10-05
Abstract
Abstract In order to modify the rate at which a friction element is engaged to effect a gear shift in a multi-forward speed automatic automotive transmission with respect to vehicle speed, an orifice valve is arranged to be responsive to a vehicle speed signal (e.g. governor pressure) in a manner to establish a second fluid path between (a) the friction element (e.g. clutch) and an accumulator associated therewith and (b) the valve (e.g. 3-4 shift valve) which supplys the actuating pressurized hydraulic fluid and therefore reduce the flow restriction between the shift valve and the friction element when the vehicle is speed is above a predetermined value.
Inventors
- 👤 Kazuhiko Sugano
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 18:48
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/04; F16H61/06; F16H61/065; F16H61/068; F16H61/067
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
98 words
In a transmission control system for a transmission having an output shaft: a friction element which is engageable to produce a forward speed ratio; a first device for selectively supplying hydraulic fluid under pressure to said friction element through a first flow restriction; a second device which produces a signal which varies with an operational parameter of said transmission; and an orifice valve interposed between said first device and said friction element for decreasing the flow restriction between said first device and said friction element in response to the magnitude of said signal increasing above a predetermined level.
Claim 2
Dependent Claim
98 words
In a transmission control system for a transmission having an output shaft: a friction element which is engageable to produce a forward speed ratio; a first device for selectively supplying hydraulic fluid under pressure to said friction element through a first flow restriction; a second device which produces a signal which varies with an operational parameter of said transmission; and an orifice valve interposed between said first device and said friction element for decreasing the flow restriction between said first device and said friction element in response to the magnitude of said signal increasing above a predetermined level.
Claim 3
Dependent Claim
42 words
A transmission control system as claimed in claim 2, further comprising: a hydraulic fluid accumulator which is fluid communicated with said friction element and which damps the rate at which the pressure transmitted via said orifice valve increases in said friction element.
Claim 4
Dependent Claim
21 words
A transmission control system as claimed in claim 1, wherein said first device takes the form of a shift control valve.
Claim 5
Dependent Claim
23 words
A transmission control system as claimed in claim 1, wherein said second device takes the form of a governor valve of said transmission.
Claim 6
Dependent Claim
78 words
A transmission control system as claimed in claim 1, wherein said orifice valve comprises: means defining a second orifice; and a valve element which establishes fluid communication between said first device and said friction element via said second orifice when in a first position thereof and which cuts off the communication when in a second position thereof, said friction element being arranged to assume said first position when the magnitude of said signal is above said predetermined level.
References Cited (Backward Citations)
No citation records indexed.
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