摘要:
A control device controls a hydrostatic transmission vehicle having a hydrostatic transmission with a variable displacement pump and a variable displacement hydraulic motor. The control device is configured to set a set vehicle speed based on a forward/rearward travel command and a gear stage command instructed by an operator, to set an upper limit of the engine speed with respect to the set vehicle speed for limiting the upper limit of the engine speed to a predetermined partial engine speed set to be lower than a high idle engine speed when the set vehicle speed is in a preliminarily set low and intermediate speed range, and to control respective displacements of the variable displacement pump and the variable displacement hydraulic motor based on the set vehicle speed for allowing a vehicle speed to reach the set vehicle speed even when the engine is rotated at the partial engine speed.
摘要:
A control device controls a hydrostatic transmission vehicle having a hydrostatic transmission including a variable displacement pump and a variable displacement hydraulic motor. The control device is configured to set a set vehicle speed based on a forward/rearward travel command and a gear stage command instructed by an operator, to set a torque limit usable for the hydrostatic transmission based on an engine speed, to set a vehicle speed limit based on a pressure in the hydraulic circuit and the torque limit, to select a lower one of the set vehicle speed and the vehicle speed limit, and to control respective displacements of the variable displacement pump and the variable displacement hydraulic motor based on the selected vehicle speed.
摘要:
A control device controls a hydrostatic transmission vehicle having a hydrostatic transmission including a variable displacement pump and a variable displacement hydraulic motor. The control device is configured to set a set vehicle speed based on a forward/rearward travel command and a gear stage command instructed by an operator, to set a torque limit usable for the hydrostatic transmission based on an engine speed, to set a vehicle speed limit based on a pressure in the hydraulic circuit and the torque limit, to select a lower one of the set vehicle speed and the vehicle speed limit, and to control respective displacements of the variable displacement pump and the variable displacement hydraulic motor based on the selected vehicle speed.
摘要:
A control device controls a hydrostatic transmission vehicle having a hydrostatic transmission with a variable displacement pump and a variable displacement hydraulic motor. The control device is configured to set a set vehicle speed based on a forward/rearward travel command and a gear stage command instructed by an operator, to set an upper limit of the engine speed with respect to the set vehicle speed for limiting the upper limit of the engine speed to a predetermined partial engine speed set to be lower than a high idle engine speed when the set vehicle speed is in a preliminarily set low and intermediate speed range, and to control respective displacements of the variable displacement pump and the variable displacement hydraulic motor based on the set vehicle speed for allowing a vehicle speed to reach the set vehicle speed even when the engine is rotated at the partial engine speed.
摘要:
A traveling control device and a traveling control program for a work vehicle in which a change in a control quantity due to an effect of vehicle body vibrations is small, fixing the desired control quantity is possible, and the control quantity can be matched with the operator's feel. A travel control program in which a first line on which the speed ratio reduces corresponding to a change in the operation stroke, a second line having hysteresis with respect to the first line and on which the speed ratio increases corresponding to a change in the operation stroke, and third lines on which the speed ratio changes corresponding to the change in the operation stroke and the change in speed ratio with respect to the change in the operation stroke is smaller than that of the first and the second line are set is installed in the control device.
摘要:
Even when an operation device with a short operation stroke range is adopted, so that a change in a control quantity (speed ratio) due to an effect of vehicle body vibrations or similar is small and it is possible to fix the desired control quantity (speed ratio), and moreover the control quantity (speed ratio) can be obtained in accordance with the operator's feel when carrying out fine adjustments by increasing and decreasing an operation stroke. A controller 20 calculates the speed ratio in accordance with a relationship L1 shown in FIG. 3, and controls the speed ratio. A travel control program in which the following are set and that carries out the calculation is installed in the controller 20. 1) A first line L11 on which the speed ratio reduces corresponding to a change in the operation stroke, a second line L12 that has hysteresis with respect to the first line L11 and on which the speed ratio increases corresponding to a change in the operation stroke, and third lines L131, L132, L133, L134 on which the speed ratio changes corresponding to the change in the operation stroke and the change in speed ratio with respect to the change in the operation stroke is smaller than that of the first line L11 and that of the second line L12 are set, 2) when the operation device 21 is operated from a point on the first line L11 in a direction that the speed ratio decreases, the speed ratio is calculated in accordance with the first line L11, 3) when the operation device 21 is operated from a point on the second line L12 in a direction that the speed ratio increases, the speed ratio is calculated in accordance with the second line L12, and 4) when the operation device 21 is operated from a point on the first line L11 in a direction that the speed ratio increases, or when the operation device 21 is operated from a point on the second line L12 in a direction that the speed ratio decreases, the speed ratio is calculated in accordance with the third lines L131, L132, L133, L134.
摘要:
An engine control device for a forklift that suppresses an increase in fuel consumption amount and noise by limiting an engine rotation speed when the forklift is driven without the need to increase the engine speed according to the accelerator operation even when the accelerator is depressed hard. Determining means in a controller determines whether all of the following conditions are satisfied: a neutral position of the traveling direction instructing means; a lift raising switch and first, second and third attachment switches are turned off. When all of the above conditions are satisfied, it is determined whether the forklift is driven in any of a plurality of states. An engine control means generates and outputs a control command to obtain the engine speed based on the accelerator pedal depression with the upper limit value of the engine speed set as an upper limit value of the engine speed.
摘要:
A control device of a forklift engine that secures operability by keeping down fuel consumption when the accelerator pedal is floored in an unloaded or lightly loaded state, and once a heavy cargo is loaded, by lifting the cargo at a maximum lifting speed and traveling with maximum travel performance without acceleration problems. At least two maximum torque curves of different magnitudes are set in advance on a torque curve diagram. Then, the weight the cargo loaded on an attachment is measured. A threshold value for selecting at least two maximum torque curves is determined. If the measured weight is less than the threshold value, the maximum torque curve with a smaller maximum torque value is selected. If the measured weight is not less than the threshold value, the maximum torque curve with a larger maximum torque value is selected. The engine is controlled using the selected maximum torque curve.
摘要:
A control device of a forklift engine that secures operability by keeping down fuel consumption when the accelerator pedal is floored in an unloaded or lightly loaded state, and once a heavy cargo is loaded, by lifting the cargo at a maximum lifting speed and traveling with maximum travel performance without acceleration problems. At least two maximum torque curves of different magnitudes are set in advance on a torque curve diagram. Then, the weight the cargo loaded on an attachment is measured. A threshold value for selecting at least two maximum torque curves is determined. If the measured weight is less than the threshold value, the maximum torque curve with a smaller maximum torque value is selected. If the measured weight is not less than the threshold value, the maximum torque curve with a larger maximum torque value is selected. The engine is controlled using the selected maximum torque curve.
摘要:
In an engine-overrun-preventing control device, if an engine speed exceeds a maximum speed, a minimum value of an inching rate is set such that higher the actual engine speed results in a higher minimum value of an inching rate. The hydraulic pump displacement is adjusted to obtain a higher inching rate between the minimum value of the inching rate and an inching rate set based on a brake stroke. If the engine speed exceeds a commanded speed and a pressure time-rate-of-change at the pump intake exceeds a prescribed value, the minimum value of the inching rate is set such that the higher the pressure time-rate-of-change, the higher the minimum value of the inching rate. The pump displacement is adjusted to obtain a higher inching rate between the minimum value of the inching rate set based on the pressure time-rate-of-change and the inching rate set based on the brake stroke.