Clutch control device for transmission

A clutch control device for a transmission associated with an engine and having a clutch for controlling the transfer of power through the transmission and a hydraulic servo unit for selectively connecting and disconnecting the clutch, said clutch control device comprising:

• a discharge oil passage for discharging working oil from the hydraulic servo unit when the clutch is connected by the hydraulic servo unit to start the transfer of power;
• an orifice disposed in said discharge oil passage for restricting the flow of the working oil discharged through said discharge oil passage;
• and
• orifice changing means for changing the connecting speed of said clutch by modifying the degree to which the flow of the working oil is restricted by said orifice, depending on the magnitude of an indication of a throttle valve opening of the engine.

A clutch control device for a transmission associated with an engine and having a clutch for controlling the transfer of power through the transmission and a hydraulic servo unit for selectively connecting and disconnecting the clutch, said clutch control device comprising:

• a discharge oil passage for discharging working oil from the hydraulic servo unit when the clutch is connected by the hydraulic servo unit to start the transfer of power;
• an orifice disposed in said discharge oil passage for restricting the flow of the working oil discharged through said discharge oil passage;
• and
• orifice changing means for changing the connecting speed of said clutch by modifying the degree to which the flow of the working oil is restricted by said orifice, depending on the magnitude of an indication of a throttle valve opening of the engine,
• wherein said discharge oil passage is branched into first and second branch discharge oil passages, said orifice comprising a first fixed orifice disposed in said first branch discharge oil passage and a second fixed orifice disposed in said second branch discharge oil passage, said orifice changing means comprising an orifice changing valve disposed in said second branch discharge oil passage and connected in series with said second fixed orifice.

A clutch control device for a transmission associated with an engine and having a clutch for controlling the transfer of power through the transmission and a hydraulic servo unit for selectively connecting and disconnecting the clutch, said clutch control device comprising:

• a discharge oil passage for discharging working oil from the hydraulic servo unit when the clutch is connected by the hydraulic servo unit to start the transfer of power;
• an orifice disposed in said discharge oil passage for restricting the flow of the working oil discharged through said discharge oil passage;
• and
• orifice changing means for changing the connecting speed of said clutch by modifying the degree to which the flow of the working oil is restricted by said orifice, depending on the magnitude of an indication of a throttle valve opening of the engine,
• wherein said clutch comprises a clutch having friction plates which are pressable against each other under a force controlled by said hydraulic servo unit.

A clutch control device for a transmission associated with an engine and having a clutch for controlling the transfer of power through the transmission and a hydraulic servo unit for selectively connecting and disconnecting the clutch, said clutch control device comprising:

• a discharge oil passage for discharging working oil from the hydraulic servo unit when the clutch is connected by the hydraulic servo unit to start the transfer of power;
• an orifice disposed in said discharge oil passage for restricting the flow of the working oil discharged through said discharge oil passage;
• and
• orifice changing means for changing the connecting speed of said clutch by modifying the degree to which the flow of the working oil is restricted by said orifice, depending on the magnitude of an indication of a throttle valve opening of the engine,
• wherein said transmission comprises a hydraulically operated continuously variable transmission having a hydraulic pump and a hydraulic motor, at least one of which has a variable displacement, and a closed hydraulic circuit interconnecting said hydraulic pump and said hydraulic motor and including a bypass passage therebetween, said clutch comprising a clutch valve disposed in said bypass passage for controlling the opening of the bypass passage.