Work vehicle and work vehicle control method

摘要

In a work vehicle, a controller controls an engine based on an engine torque curve for defining a relationship between an engine speed, an engine output torque, and an operation amount of an accelerator operation member. The controller controls the engine based on a first engine torque curve during torque conversion travel. The controller controls the engine based on a second engine torque curve during lockup travel. The engine output torque of the second engine torque curve is less than the engine output torque of the first engine torque curve in at least a portion of a range of the engine speed when at least the operation amount of the accelerator operation member is a predetermined operation amount that is less than a maximum operation amount.

主权项

1. A work vehicle comprising:
an engine; a travel device configured to cause the work vehicle to travel, the travel device being driven by a drive force from the engine; a hydraulic pump configured to discharge hydraulic fluid, the hydraulic pump being driven by the drive force from the engine; a work implement driven by the hydraulic fluid from the hydraulic pump; a torque converter device configured to transmit the drive force from the engine to the travel device, the torque converter device having a torque converter and a lockup clutch; an accelerator operation member operated by an operator; an accelerator operation detector configured to detect an operation amount of the accelerator operation member; and a controller configured to control the engine based on one of at least a first engine torque curve and a second engine torque curve, each of the first and second torque curves defining a relationship between an engine speed, an engine output torque, and the operation amount of the accelerator operation member, the first engine torque curve being different from the second engine torque curve, the controller being further configured to
control the engine based on the first engine torque curve during torque conversion travel in which the lockup clutch is in a non-connected state,change to controlling the engine based on the second engine torque curve after the controller determines that the lockup clutch has been switched from the non-connected state to a connected state, and the engine output torque of the second engine torque curve being less than the engine output torque of the first engine torque curve at least at a switch speed at which a switch is made from the non-connected state to the connected state of the lockup clutch when the operation amount of the accelerator operation member is a predetermined operation amount that is less than a maximum operation amount.