EP0123047A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Hydraulic control system for automatic transmission with shockless 4-3 and 4-2 shifting
Assignee: Nissan Motor Co Ltd
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Filing: 1984-02-21
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Granted: —
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Expires: 2004-02-21
Abstract
Abstract Disclosed herein is a hydraulic control system for an automatic transmission wherein a first friction unit (C3) is engaged in downshifting from the 4th speed ratio to the 3rd speed ratio and it is engaged in downshifting from the 4th speed ratio to the 2nd speed ratio. A first port (124g) of a 3-4 shift valve (24) communicates with the first friction unit (C3) and it is allowed to communicate with a second port (124h) when the 3-4 shift valve (22) assumes a downshift position thereof. The second port (124h) communicates via a first passage (454) with a fluid conduit (412) supplied with an actuating fluid pressure. A second passage (452) is provided which connects the second port (124h) to the fluid conduit (412). The first and second passages are provided with first and second orifice devices (662, 660), respectively. The second fluid passage (452) is blocked when a 2-3 shift valve (22) assumes a downshift position thereof.
Inventors
- 👤 Kazuhiko Sugano
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 12:04
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/04; F16H61/06; F16H61/065; F16H2061/0444; F16H61/08
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
368 words
A hydraulic control system for an automatic transmission which is shiftable into a n th speed ratio, a n + 1 th speed ratio and a n + 2 th speed ratio, the automatic transmission including a first friction unit and a second friction unit, the first friction unit being engaged and the second friction unit being released during operation with the n th speed ratio, the first and second friction units being engaged during operation with the n + 1 th speed ratio, the first friction unit being released and the second friction unit being engaged during operation. with the n + 2 th speed ratio, the hydraulic control system comprising: means for generating an actuating fluid pressure; a first shift valve having a downshift position thereof and an upshift position thereof, said first shift valve assuming the downshift position thereof during operation with the n th speed ratio, said first shift valve assuming the upshift position thereof during operation with the n + 1 th speed ratio and the n + 2 th speed ratio; a second shift valve having a downshift position thereof and an upshift position thereof, said second shift valve assuming the downshift position thereof during operation with the n th speed ratio and the n + 1 th speed ratio, said second shift valve assuming the upshift position thereof during operation with the n + 2 th speed ratio; said second shift valve having a first port and a second port, said first port being allowed to communicate with. said second port when said second shift valve assumes the downshift position thereof, the first port communicating with the first friction unit; means defining a first fluid supply passage having one end communicating with th ^ second port and an opposite end communicating with said actuating fluid pressure generating means; a first orifice device fluidly disposed in said first fluid supply passage; means for providing a second fluid supply passage having one end communicating with the second port and an opposite end communicating with said actuating fluid pressure generating means when said first shift valve assumes the upshift position thereof; and a second orifice device fluidly disposed in said second fluid supply passage.
Claim 2
Dependent Claim
368 words
A hydraulic control system for an automatic transmission which is shiftable into a n th speed ratio, a n + 1 th speed ratio and a n + 2 th speed ratio, the automatic transmission including a first friction unit and a second friction unit, the first friction unit being engaged and the second friction unit being released during operation with the n th speed ratio, the first and second friction units being engaged during operation with the n + 1 th speed ratio, the first friction unit being released and the second friction unit being engaged during operation. with the n + 2 th speed ratio, the hydraulic control system comprising: means for generating an actuating fluid pressure; a first shift valve having a downshift position thereof and an upshift position thereof, said first shift valve assuming the downshift position thereof during operation with the n th speed ratio, said first shift valve assuming the upshift position thereof during operation with the n + 1 th speed ratio and the n + 2 th speed ratio; a second shift valve having a downshift position thereof and an upshift position thereof, said second shift valve assuming the downshift position thereof during operation with the n th speed ratio and the n + 1 th speed ratio, said second shift valve assuming the upshift position thereof during operation with the n + 2 th speed ratio; said second shift valve having a first port and a second port, said first port being allowed to communicate with. said second port when said second shift valve assumes the downshift position thereof, the first port communicating with the first friction unit; means defining a first fluid supply passage having one end communicating with th ^ second port and an opposite end communicating with said actuating fluid pressure generating means; a first orifice device fluidly disposed in said first fluid supply passage; means for providing a second fluid supply passage having one end communicating with the second port and an opposite end communicating with said actuating fluid pressure generating means when said first shift valve assumes the upshift position thereof; and a second orifice device fluidly disposed in said second fluid supply passage.
Claim 3
Dependent Claim
27 words
A hydraulic control system as claimed in claim 1, wherein said second orifice device is larger in a flow sectional area than said first orifice device is.
References Cited (Backward Citations)
No citation records indexed.
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