Hydraulic transmission vehicle
First Claim
1. A hydraulic drive vehicle, comprising:
- speed change operation means;
a hydraulic transmission having a swash plate;
an actuator, wherein a slant angle of the swash plate is changed via the actuator corresponding to operation of the speed change operation means so as to change an output/input rotation speed ratio of the hydraulic transmission;
an axle;
a drive shaft interlocking with the axle; and
rotation speed detection means for detecting a rotation speed of the drive shaft interlocking with the axle, wherein a target rotation speed of the drive shaft is set to a value corresponding to the slant angle of the swash plate set by operation of the speed change operation means, and wherein, if a rotation speed of the drive shaft detected by the rotation speed detection means differs from the target rotation speed, the slant angle of the swash plate is compensatively controlled via the actuator.
0 Assignments
0 Petitions
Accused Products
Abstract
A hydraulic transmission (21) has an electric actuator (86) for changing its output/input rotation speed ratio. A controller (90) of the actuator memorizes a command current value to the actuator supposing that load is not applied on the hydraulic transmission, and calculates a value of load applied on the hydraulic transmission by calculating a difference between an actual command current value to the actuator and the memorized command current value. A command current value is compensated based on the value of load, and the actuator receives feedback to be controlled. A vehicle may have a differential mechanism (10), which combines rotation powers on input side and output side of the hydraulic transmission. A detector (82) detects rotation speed of a main speed change output shaft (27) serving as an output shaft of the differential mechanism. If the detected rotation speed differs from target rotation speed of the shaft (27) determined based on operation of a speed change operation tool, the actuator is forcedly controlled. This difference is supposed to be caused by load applied on the hydraulic transmission, whereby the load is calculated.
31 Citations
14 Claims
-
1. A hydraulic drive vehicle, comprising:
-
speed change operation means; a hydraulic transmission having a swash plate; an actuator, wherein a slant angle of the swash plate is changed via the actuator corresponding to operation of the speed change operation means so as to change an output/input rotation speed ratio of the hydraulic transmission; an axle; a drive shaft interlocking with the axle; and rotation speed detection means for detecting a rotation speed of the drive shaft interlocking with the axle, wherein a target rotation speed of the drive shaft is set to a value corresponding to the slant angle of the swash plate set by operation of the speed change operation means, and wherein, if a rotation speed of the drive shaft detected by the rotation speed detection means differs from the target rotation speed, the slant angle of the swash plate is compensatively controlled via the actuator. - View Dependent Claims (2, 3, 4, 5, 7, 8, 9, 10, 11, 12, 13, 14)
-
-
6. A hydraulic drive vehicle, comprising:
-
speed change operation means; a hydraulic transmission having a swash plate; an actuator, wherein a slant angle of the swash plate is changed via the actuator corresponding to operation of the speed change operation means so as to change an output/input rotation speed ratio of the hydraulic transmission; and a differential mechanism which combines powers of input side and output side of the hydraulic transmission, wherein a drive mode of the vehicle can be switched between a mode setting output of the hydraulic transmission without passing the differential mechanism as traveling drive power and a mode setting output of the differential mechanism as traveling drive power, and the actuator is controlled so as to reduce a change rate of the swash plate position at the time of switching the drive mode while moving the movable swash plate to a set target position of the swash plate.
-
Specification