Work vehicle and control method for work vehicle
AssigneeKubota Corporation
InventorsKohei Nagao, Daiki Abe, Ryota Hamamoto
Life of this patent
Estimating the term…
Abstract
A work vehicle includes a primary pressure control valve configured to control a pilot primary pressure of pilot oil. A secondary pressure control valve is configured to control a pilot secondary pressure of the pilot oil. Control circuitry is configured to control a rotation speed of an engine according to a target rotation speed. The control circuitry is configured to control the primary pressure control valve and the secondary pressure control valve based on a first target value of the pilot primary pressure and a second target value of the pilot secondary pressure.
Claims6
A work vehicle comprising:
- a hydraulic motor configured to drive a traveling device;
- a hydraulic pump having a pilot port to which pilot pressure of pilot oil is applied, the hydraulic pump being configured to supply hydraulic fluid to the hydraulic motor in accordance with the pilot pressure;
- an engine configured to drive the hydraulic pump;
- a rotation speed sensor configured to detect a rotation speed of the engine;
- a pilot pump configured to be driven by the engine to discharge the pilot oil;
- an operation lever configured to receive an instruction of a travel direction from a user;
- an operation valve configured to control the pilot pressure by operation of the operation lever;
- a first pilot oil passage connecting the pilot pump and the operation valve, the pilot oil being supplied through the first pilot oil passage;
- a primary pressure control valve provided in the first pilot oil passage and configured to control a pilot primary pressure which is a pressure of the pilot oil in the first pilot oil passage;
- a second pilot oil passage connecting the operation valve and the pilot port, the pilot oil being supplied through the second pilot oil passage;
- a secondary pressure control valve connected to the second pilot oil passage and configured to control a pilot secondary pressure which is a pressure of the pilot oil in the second pilot oil passage;
- and
- control circuitry configured to control the rotation speed of the engine according to a target rotation speed of the engine, and control the primary pressure control valve and the secondary pressure control valve based on a first target value of the pilot primary pressure and a second target value of the pilot secondary pressure.
A control method for a work vehicle, comprising:
- detecting a rotation speed of an engine;
- controlling the engine such that the rotation speed of the engine becomes a target rotation speed;
- driving a hydraulic pump connected to the engine such that the hydraulic pump discharges hydraulic fluid to a hydraulic motor connected to a traveling device;
- driving a pilot pump connected to the engine such that the pilot pump discharges pilot oil to a first pilot oil passage;
- controlling an operation valve connected to the first pilot oil passage according to an instruction of a traveling direction by a user to convert a pilot primary pressure, which is a pressure of the pilot oil provided through the first pilot oil passage, into a pilot secondary pressure to be applied to the pilot oil in a second pilot oil passage connecting the operation valve and a pilot port of the hydraulic pump;
- controlling a primary pressure control valve provided in the first pilot oil passage to adjust the pilot primary pressure to a first target value;
- and
- controlling a secondary pressure control valve connected to the second pilot oil passage to adjust the pilot secondary pressure to a second target value.
Dependencies are inferred from the claim text.