Hydraulic control unit for a vehicle automatic transmission
AssigneeHonda Giken Kogyo Kabushiki Kaisha
InventorTsunefumi Niiyama
Life of this patent
Estimating the term…
Abstract
A hydraulic control unit for an automatic transmission having a plurality of power transmitting paths and a plurality of engaging clutches and/or brakes for selecting any one of the transmitting paths to set a gear position. The unit comprises a regulator valve for producing a line pressure, an operating pressure control valve for producing an operating pressure supplied to the engaging clutch or brake by regulating the line pressure from the regulator valve, and a line pressure switching valve for making the line pressure produced by the regulator valve low at a specified gear position when a target operating pressure set by the operating pressure control valve is lower than a specified value and making the line pressure high when the target operating pressure is higher than the specified value.
Claims13
A hydraulic control unit for an automatic transmission having a plurality of power transmitting paths and a plurality of engaging means for selecting any one of said transmitting paths to set a gear position comprising:
- regulator valve means for producing a line pressure;
- operating pressure control means for producing an operating pressure supplied to said engaging means by regulating said line pressure from said regulator valve;
- and
- line pressure switching means for making the line pressure produced by said regulator valve low when a target operating pressure set by said operating pressure control means is lower than a specified value and making the line pressure high when the target operating pressure is higher than the specified value during a shift to a specified gear position.
A hydraulic control unit for an automatic transmission having a plurality of power transmitting paths and a plurality of engaging means for selecting any one of said transmitting paths to set a gear position comprising:
- regulator valve means for producing a line pressure;
- operating pressure control means for producing an operating pressure supplied to said engaging means by regulating said line pressure from said regulator valve;
- a shift lever for selecting a shift range;
- a manual valve moved to a position corresponding to said shift range selected by said shift lever,
- said operating pressure being allowed by said manual valve to be supplied to said engaging means corresponding to said selected shift range;
- a first opening-closing valve disposed on a hydraulic passage connecting said operating pressure control means with an engine brake engaging means which is engaged when an engine braking is required and disconnecting said operating pressure control means from said engine brake engaging means to disengage said engine brake engaging means when engine braking is not required;
- and
- the operations of said opening-closing valve being controlled based on the position of said manual valve.
Dependencies are inferred from the claim text.