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US 6,805,649 B2Granted
Hydraulic control system for automatic transmission
AssigneeHyundai Motor Company
InventorsTae-Kyun Kim, Byung-Kwan Shin
Life of this patent
Estimating the term…
Abstract
A hydraulic control system, in which a powertrain of a 5-speed automatic transmission is controlled using five clutches and three brakes such that fuel consumption is reduced and engine torque is more efficiently utilized. The hydraulic control system includes four pressure control valves, three switching valves, and three fail-safe valves that are controlled by solenoid valves.
Claims19
A hydraulic control system for automatic transmissions, comprising:
- a manual valve indexed with a driver-operated shift selector;
- a first pressure control valve controlled by a control pressure of a first solenoid valve, the first pressure control valve supplying N range pressure supplied from the manual valve selectively to a fifth clutch in fourth and fifth speeds, and to a first brake in a neutral N range and a low L range;
- a second pressure control valve controlled by a control pressure of a second solenoid valve, the second pressure control valve supplying D range pressure supplied from the manual valve selectively to a second brake in a second speed and the fifth speed, and, simultaneously, as control pressure of a first fail-safe valve;
- a third pressure control valve controlled by a control pressure of a third solenoid valve, the third pressure control valve supplying D range pressure supplied from the manual valve to a first clutch in a first speed, and to a fourth clutch in a low L range and in second, third, and fourth speeds;
- a fourth pressure control valve controlled by a control pressure of a fourth solenoid valve, the fourth pressure control valve supplying line pressure as control pressure of a third brake and the third solenoid valve in first, second, and third speeds, and in a reverse R range and the neutral N range;
- a first switching valve to selectively supply D range pressure, first pressure control valve pressure, and line pressure to the first clutch and to the fourth clutch, the fourth clutch operating in the first, second, third, and fourth speeds and in the reverse R and low L ranges;
- a second switching valve controlled by L range pressure, D range pressure, and control pressure of a fifth solenoid valve, and undergoing port conversion to selectively supply hydraulic pressure supplied to the first pressure control valve to a second clutch and the first brake, which operate in the third, fourth, and fifth speeds;
- a fifth solenoid valve for controlling a control pressure supplied from a reducing valve to selectively supply the pressure as control pressure to the first and second switching valves;
- a third switching valve controlled by line pressure and second clutch pressure, and selectively supplying hydraulic pressure supplied from the second switching valve to the second clutch and the fifth clutch;
- an N-R control valve controlled by control pressure of the second solenoid valve, and supplying R range pressure supplied from the manual valve to a third clutch in the reverse R range;
- the first fail-safe valve controlled by line pressure, second brake pressure, and second clutch pressure, and selectively supplying hydraulic pressure supplied to the manual valve and the second switching valve to the first brake, the first fail-safe valve preventing the simultaneous engagement of the first and second brakes, and preventing forward driving by engagement of the first brake and the second clutch when in the neutral N range;
- a second fail-safe valve controlled by R range pressure, second and fourth clutch pressure, and N range pressure, the second fail-safe valve preventing the simultaneous engagement of the second brake and the first, second, and fourth clutches, and selectively supplying hydraulic pressure supplied from the second pressure control valve to the second brake;
- and
- a third fail-safe valve controlled by D range pressure and third brake pressure, and selectively supplying hydraulic pressure supplied from the third switching valve to the fifth clutch, the third fail-safe valve preventing the simultaneous operation of the third brake and the fifth clutch.
11 more elements
A hydraulic control system for a five speed automatic transmission having five drive range speeds, a reverse range and a neutral range, wherein said transmission includes a plurality of clutches and brakes, said control system comprising:
- a manual valve indexed with a driver-operated shift selector;
- a first pressure control valve supplying neutral range pressure supplied from the manual valve selectively to a clutch in the fourth and fifth speeds, and to a brake in the neutral N range and the low L range;
- a second pressure control valve supplying D range pressure supplied from the manual valve selectively to another brake in a second speed and the fifth speed, and, simultaneously, as control pressure of a first fail-safe valve;
- a third pressure control valve supplying D range pressure supplied from the manual valve to another clutch in a first speed, and to a different clutch in a low L range and in second, third, and fourth speeds;
- a fourth pressure control valve supplying line pressure as control pressure of a brake in first, second, and third speeds, and in the reverse R range and the neutral N range;
- a first switching valve selectively supplying D range pressure and line pressure to two clutches, at least one clutch being operated in the first, second, third, and fourth speeds and in the reverse R and low L ranges;
- a second switching valve selectively supplying hydraulic pressure supplied to the first pressure control valve to a clutch and a brake operable in the third, fourth, and fifth speeds;
- a fifth solenoid valve for controlling a control pressure supplied from a reducing valve to selectively supply the pressure as control pressure to the first and second switching valves;
- a third switching valve selectively supplying hydraulic pressure supplied from the second switching valve to a second clutch and a fifth clutch;
- and
- an N-R control valve supplying R range pressure supplied from the manual valve to a clutch in the reverse R range.
8 more elements
A hydraulic control system for a five speed automatic transmission having five drive range speeds, a reverse range and a neutral range, wherein said transmission includes a plurality of friction elements, said plurality of friction elements including at least one friction element operated only at the drive range speeds and at least one friction element operated only at the reverse range, said control system comprising:
- a manual valve indexed with a driver-operated shift selector, said manual valve selectively outputting D range pressure or R range pressure;
- and
- a hydraulic pressure distributing unit supplying only said D range pressure selectively to said at least one friction element operated only at the drive range speeds, and supplying only said R range pressure selectively to said at least one friction element operated only at the reverse range, wherein
- said plurality of friction elements includes a first clutch and a first brake, both of which are connected to a same operating element of the transmission, the operating element being one of a ring gear, a carrier, and a sun gear;
- the hydraulic pressure distributing unit comprises a switch valve for selectively supplying hydraulic pressure to the first clutch and the first brake such that simultaneous operation of the first clutch and first brake is prevented;
- and
- a hydraulic pressure supply line for supplying hydraulic pressure to the first clutch a hydraulic pressure supply line for supplying hydraulic pressure to the first brake meet at the switch valve.
4 more elements
Dependencies are inferred from the claim text.