Power transmission mechanism for automotive vehicles

Claim 2

A power transmission mechanism for automative vehicles comprising a variable displacement engine which can be selectively placed in a first operation mode in which all of the cylinders are active and a second operation mode in which selected ones of the cylinders are only active, under control of number-of-cylinder control means including means for changing over the number of active cylinders, fluid coupling means disposed between a driving shaft of said variable displacement engine and a driven shaft in a vehicle for effecting torque transmission between said driving shaft and said driven shaft, direct coupling means disposed between said driving shaft and said driven shaft for effecting torque transmission between said driving shaft and said driven shaft in a relation functionally parallel to the torque transmission through said fluid coupling means, suspension cylinder determining means for generating and applying a command signal commanding change-over of the number of active cylinders to said number-of-cylinder control means so as to place said variable displacement engine in one of said first operation mode and said second operation mode depending on the operating conditions of at least one of said engine and said vehicle, and coupling change-over means operative in response to the command signal generated from said suspension cylinder determining means for selectively effecting the torque transmission through said fluid coupling means and said direct coupling means, said coupling change-over means operating so that the torque transmission between said driving shaft and said driven shaft is effected through said fluid coupling means during change-over of the number of active cylinders and during the operation of said engine of said second operation mode under command of the command signal generated from said suspension cylinder determining means.

Claim 3

A power transmission mechanism as claimed in claim 1, further comprising means for determining an operation range permitting operation of said direct coupling means when said variable displacement engine operates in said second operation mode in which the selected ones of the cylinders are only active, said operation-range determining means detecting a specific operating condition of said variable displacement engine when said engine is operating in said second operation mode and applying a direct-coupling permission signal to said coupling change-over means, so that said direct coupling means is permitted to operate prior to the operation of said suspension cylinder determining means.

Claim 4

A power transmission mechanism as claimed in claim 2, wherein said specific operating condition is an operating condition in which the rotation speed of said variable displacement engine is higher than a setting, and the throttle valve in said engine is full closed.

Claim 5

A power transmission mechanism as claimed in claim 2, wherein said specific operating condition is an operating condition in which the speed of the vehicle is higher than a setting, and the transmission having said driven shaft is shifted to a position other than its neutral position.

Claim 6

A power transmission mechanism for automotive vehicles comprising a variable displacement engine which can be selectively placed in a first operation mode in which all of the cylinders are active and a second operation mode in which selected ones of the cylinders are only active, under control of number-of-cylinder control means including means for changing over the number of active cylinders, fluid coupling means disposed between a driving shaft of said variable displacement engine and a driven shaft in a vehicle for effecting torque transmission between said driving shaft and said driven shaft, direct coupling means disposed between said driving shaft and said driven shaft for effecting torque transmission between said driving shaft and said driven shaft in a relation functionally parallel to the torque transmission through said fluid coupling means, suspension cylinder determining means for generating and applying a command signal commanding the number of active cylinders to said number-of-cylinder control means so as to place said variable displacement engine in one of said first operation mode and said second operation mode depending on the operating conditions of at least one of said engine and said vehicle, coupling change-over means operative in response to the command signal generated from said suspension cylinder determining means for selectively actuating said direct coupling means in said first operation mode and selectively actuating said fluid coupling means in said second operation mode, first delaying means for delaying transmission to said number-of-cylinder control means of a change-over command signal generated from said suspension cylinder determining means to command change-over from said first operation mode to said second operation mode, and second delaying means for delaying transmission to said coupling change-over means of a change-over command signal generated from said suspension cylinder determining means to command change-over from said second operation mode to said first operation mode, said coupling change-over means operating so that the torque transmission between said driving shaft and said driven shaft is effected through said fluid coupling means during change-over of the number of active cylinders under command of the command signal generated from said suspension cylinder determining means.

Claim 7

A power transmission mechanism for automotive vehicles comprising a variable displacement engine which can be selectively placed in a first operation mode in which all of the cylinders are active and a second operation mode in which selected ones of the cylinders are only active, under control of number-of-cylinder control means including means for changing over the number of active cylinders, fluid coupling means disposed between a driving shaft of said variable displacement engine and a driven shaft in a vehicle for effecting torque transmission between said driving shaft and said driven shaft, direct coupling means disposed between said driving shaft and said driven shaft for effecting torque transmission between said driving shaft and said driven shaft in a relation functionally parallel to the torque transmission through said fluid coupling means, suspension cylinder determining means for generating and applying a command signal commanding the number of active cylinders to said number-of-cylinder control means so as to place said variable displacement engine in one of said first operation mode and said second operation mode depending on the operating conditions of at least one of said engine and said vehicle, coupling change-over means operative in response to the command signal generated from said suspension cylinder determining means for selectively actuating said direct coupling means in said first operation mode and selectively actuating said fluid coupling means in said second operation mode, first delaying means for delaying transmission to said number-of-cylinder control means of a change-over command signal generated from said suspension cylinder determining means to command change-over from said first operation mode to said second operation mode, and second delaying means for delaying transmission to said coupling change-over means of a change-over command signal generated from said suspension cylinder determining means to command change-over from said second operation mode to said first operation mode, said coupling change-over means operating so that the torque transmission between said driving shaft and said driven shaft is effected through said fluid coupling means during change-over of the number of active cylinders under command of the command signal generated from said suspension cylinder determining means.