Steering control device for vehicle having continuously variable transmission

A steering control device for a vehicle comprising:

• a steering wheel;
• a pair of hydrostatic continuously variable transmissions each having a hydraulic pump and a hydraulic motor;
• left and right driven wheels connected to said pair of hydrostatic continuously variable transmissions and driven independently;
• left and right wheels to be steered which are connected to said steering wheel;
• and
• a control means for controlling a transmission ratio of said pair of hydrostatic continuously variable transmissions in accordance with a steering angle of said steering wheel so as to turn the vehicle, wherein as the steering angle increases, an inner wheel speed during turning of the vehicle is decreased and an outer wheel speed during turning of the vehicle is increased, and when the steering angle approaches a limit steering angle, the inner wheel speed during turning of the vehicle becomes zero and a stationary turn of the vehicle is conducted.

A steering control device for a vehicle comprising:

• a steering wheel;
• a pair of continuously variable transmissions;
• left and right driven wheels connected to said pair of continuously variable transmissions and driven independently;
• left and right wheels to be steered which are connected to said steering wheel;
• a control means for controlling a transmission ratio of said pair of continuously variable transmissions in accordance with a steering angle of the steering wheel so as to turn the vehicle, said control means including
• a mixing lever pivotally supported at one end thereof for longitudinal swinging movement and lateral swinging movement so as to operate a speed adjusting member for each of the pair of continuously variable transmissions to control the transmission ratio of said pair continuously variable transmissions,
• a change lever for longitudinally swinging said mixing lever to increase or decrease the number of rotations of said pair of continuously variable transmissions at substantially the same values, and
• a guide member laterally swung by said steering wheel and having a guide groove which extends longitudinally and into which the other end of said mixing lever is loosely fitted, wherein
• a width of said guide groove in a lateral direction a) is set wide at a position thereof corresponding to a low speed when said mixing lever is at forward running of the vehicle and at backward running of the vehicle, and b) is set narrow at a position thereof corresponding to a high speed when said mixing lever is at forward running of the vehicle.