WORK VEHICLE AND METHOD OF CONTROLLING WORK VEHICLE
First Claim
1. A work vehicle provided with an implement, the work vehicle comprising:
- an engine;
a variable displacement travel hydraulic pump configured to be driven by the engine;
a hydraulic motor forming a closed circuit with the travel hydraulic pump and configured to be driven by hydraulic fluid discharged from the travel hydraulic pump;
a driven wheel configured to be driven by the hydraulic motor to allow the work vehicle to travel;
a selector switch configured to detect an operating state of a traveling direction switching device configured to switch a traveling of the work vehicle between forward and backward; and
a control device configured to set, in a case in which the selector switch detects a reversal operation of the traveling direction switching device to reverse a traveling direction of the work vehicle when the work vehicle travels, a relationship between a vehicle speed of the work vehicle and an upper limit of a rotational speed of the engine in a manner such that the upper limit increases as an absolute value of the vehicle speed approaches zero, the control device being configured to obtain an upper limit of a rotational speed of the engine from the set relationship and a vehicle speed of the work vehicle.
2 Assignments
0 Petitions
Accused Products
Abstract
A work vehicle includes a variable displacement hydraulic pump driven by an engine, a hydraulic motor forming a closed circuit with the pump and driven by hydraulic fluid discharged from the pump, wheels driven by the motor to allow the work vehicle to travel, a selector detecting an operating state of a switch switching the traveling of the work vehicle between forward and backward, and a controller. When the selector detects a reversal operation of the switch to reverse the traveling direction when the work vehicle travels, the controller sets relationship between the vehicle speed of the work vehicle and the upper limit of the rotational speed of the engine such that the upper limit increases as the absolute value of the vehicle speed approaches zero. The controller obtains an upper limit of the rotational speed from the relationship and a vehicle speed of the work vehicle.
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Citations
6 Claims
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1. A work vehicle provided with an implement, the work vehicle comprising:
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an engine; a variable displacement travel hydraulic pump configured to be driven by the engine; a hydraulic motor forming a closed circuit with the travel hydraulic pump and configured to be driven by hydraulic fluid discharged from the travel hydraulic pump; a driven wheel configured to be driven by the hydraulic motor to allow the work vehicle to travel; a selector switch configured to detect an operating state of a traveling direction switching device configured to switch a traveling of the work vehicle between forward and backward; and a control device configured to set, in a case in which the selector switch detects a reversal operation of the traveling direction switching device to reverse a traveling direction of the work vehicle when the work vehicle travels, a relationship between a vehicle speed of the work vehicle and an upper limit of a rotational speed of the engine in a manner such that the upper limit increases as an absolute value of the vehicle speed approaches zero, the control device being configured to obtain an upper limit of a rotational speed of the engine from the set relationship and a vehicle speed of the work vehicle. - View Dependent Claims (2, 3, 4, 5)
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6. A method of controlling a work vehicle, the work vehicle including an implement, an engine, a variable displacement travel hydraulic pump configured to be driven by the engine, a hydraulic motor forming a closed circuit with the travel hydraulic pump and configured to be driven by hydraulic fluid discharged from the travel hydraulic pump, a driven wheel configured to be driven by the hydraulic motor, a selector switch configured to detect an operating state of a traveling direction switching device configured to switch traveling of the work vehicle between forward and backward, the method comprising:
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detecting an operation on the traveling direction switching device when the work vehicle travels; setting, in a case in which the selector switch detects a reversal operation of the traveling direction switching device to reverse a traveling direction of the work vehicle when the work vehicle travels, a relationship between a vehicle speed of the work vehicle and an upper limit of a rotational speed of the engine in a manner such that the upper limit increases as an absolute value of the vehicle speed approaches zero; and obtaining an upper limit of a rotational speed of the engine from the relationship and a vehicle speed of the work vehicle.
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Specification