US 7,771,314 B2 · Controller of work vehicle

Abstract

A control apparatus for a tractor or wheel loader includes a speed change sensor that detects the step-on amount of a speed change pedal, an actuator that regulates a swash plate angle of a hydraulic pump based on the detection value of the speed change sensor, a transmission output unit rotation sensor that detects the revolution speed of an output shalt, and a control unit. When the speed change pedal is not stepped on, a braking force is applied to travel wheels and both of a forward drive clutch and a reverse drive clutch are disengaged. When a transmission drive output detected with the transmission output unit rotation sensor is not more than a fixed forward or reverse drive switching speed, either the forward drive clutch or the reverse drive clutch is engaged as the speed change pedal is stepped on.

Claims19

Dependent claims

A control apparatus for a work vehicle provided with a hydraulic stepless transmission for transmitting power from an engine mounted on a traveling body equipped with travel wheels, a speed change pedal for changing a speed change ratio of the hydraulic stepless transmission, a forward drive clutch and a reverse drive clutch that transmit a transmission drive output from the hydraulic stepless transmission to the travel wheels, and a brake for braking the travel wheels, the control apparatus comprising:

a transmission sensor that detects a step-on amount of the speed change pedal;
a transmission output unit rotation sensor that detects a revolution speed of an output shaft;
and a controller;
wherein the control apparatus conducts control so that any one of the forward drive clutch and reverse drive clutch is engaged in response to a step-on actuation of the speed change pedal when a transmission drive output detected by the transmission output unit rotation sensor is no greater than a forward-reverse drive switching speed, and that the brake of the travel wheels is released when the activation of any of the forward drive clutch and reverse drive clutch is confirmed;
wherein the control apparatus further comprises a speed change ratio setting device for setting a speed change ratio pattern of the hydraulic stepless transmission, and a pattern storage for storing a plurality of speed change ratio patterns;
and
wherein an output revolution speed of the hydraulic stepless transmission is controlled in accordance with a speed change ratio pattern set in advance by the speed change ratio setting device correspondingly to a step-on amount of the speed change pedal.

4 more elements

a transmission sensor that detects a step-on amount of the speed change pedal;
a transmission output unit rotation sensor that detects a revolution speed of an output shaft;
and a controller;
wherein the control apparatus conducts control so that any one of the forward drive clutch and reverse drive clutch is engaged in response to a step-on actuation of the speed change pedal when a transmission drive output detected by the transmission output unit rotation sensor is no greater than a forward-reverse drive switching speed, and that the brake of the travel wheels is released when the activation of any of the forward drive clutch and reverse drive clutch is confirmed;
wherein the speed change pedal comprises a forward drive pedal and a reverse drive pedal;
and
wherein the control apparatus further comprises:
a transmission link mechanism for transmitting the pedal step-on amount of the forward drive pedal and reverse drive pedal to a speed change sensor;
and a neutral position restorer provided in the transmission link mechanism.

6 more elements

Dependencies are inferred from the claim text.

Controller of work vehicle

Life of this patent

Controller of work vehicle

Life of this patent

Abstract

Claims19