Abstract: In a working vehicle, it is possible to achieve a downsizing of an engine by securing an output torque in a low rotating region of the engine without using any supercharger. In the working vehicle having the engine mounted to a travel machine body, a common rail type fuel injection device which injects fuel to the engine, and a continuously variable transmission which shifts power from the engine, a rotating speed N of the engine is limited to two kinds, N#1 and N#2. Further, a change gear ratio of the continuously variable transmission is changed and regulated in such a manner as not to change a vehicle speed of the travel machine body before and after changing the rotation speed N whichever of the two kinds N#1 and N#2 the rotating speed N of the engine is changed to.

Abstract: In a working vehicle provided with an engine which is mounted to a travel machine body, a common rail type fuel injection device which injects fuel to the engine, a continuously variable transmission which shifts power from the engine, and the exhaust gas purification device which is arranged in an exhaust system of the engine, in the case that an engine operating point Q relating to a rotating speed N and a torque T of the engine is in a low-speed and low-torque side incapable of self-renewing the exhaust gas purification device, the engine operating point Q is changed to a high-speed and low-torque side capable of self-renewing the exhaust gas purification device, and a change gear ratio of the continuously variable transmission is changed and regulated in such a manner that a vehicle speed V of the travel machine body is not changed.

Abstract: In a working vehicle, there is dissolved a risk that a black smoke is discharged, a knocking is generated and an engine stall is caused, if a lot of load is applied to a rotary tiller during various works while traveling at a low speed. In the working vehicle provided with an engine which is mounted to a travel machine body, a common rail type fuel injection device which injects fuel to the engine, and a continuously variable transmission which shifts power from the engine, an engine driving point Q (Q1?Q2) relating to a rotating speed N and a torque T of the engine is changed in such a manner that the rotation speed come to a high speed side rotating speed N2 dissolving an overload, and a change gear ratio of the continuously variable transmission is modified and regulates in such a manner that a vehicle speed V of the travel machine body does not change in the case that the overload acts on the engine of having a low speed N1 in the rotating speed N.

Abstract: In a working vehicle, it is possible to achieve a downsizing of an engine by securing an output torque in a low rotating region of the engine without using any supercharger. In the working vehicle having the engine mounted to a travel machine body, a common rail type fuel injection device which injects fuel to the engine, and a continuously variable transmission which shifts power from the engine, a rotating speed N of the engine is limited to two kinds, N#1 and N#2. Further, a change gear ratio of the continuously variable transmission is changed and regulated in such a manner as not to change a vehicle speed of the travel machine body before and after changing the rotation speed N whichever of the two kinds N#1 and N#2 the rotating speed N of the engine is changed to.

Abstract: In a working vehicle 141, there is dissolved a risk that a black smoke is discharged, a knocking is generated and an engine stall is caused, if a lot of load is applied to a rotary tiller 24 during various works while traveling at a low speed. In the working vehicle 141 provided with an engine 70 which is mounted to a travel machine body 142, a common rail type fuel injection device 117 which injects fuel to the engine 70, and a continuously variable transmission 159 which shifts power from the engine 70, an engine driving point Q (Q1?Q2) relating to a rotating speed N and a torque T of the engine 70 is changed in such a manner that the rotation speed come to a high speed side rotating speed N2 dissolving an overload, and a change gear ratio of the continuously variable transmission 159 is modified and regulates in such a manner that a vehicle speed V of the travel machine body 142 does not change in the case that the overload acts on the engine 70 of having a low speed N1 in the rotating speed N.

Abstract: In a working vehicle provided with an engine which is mounted to a travel machine body, a common rail type fuel injection device which injects fuel to the engine, a continuously variable transmission which shifts power from the engine, and the exhaust gas purification device which is arranged in an exhaust system of the engine, in the case that an engine operating point Q relating to a rotating speed N and a torque T of the engine is in a low-speed and low-torque side incapable of self-renewing the exhaust gas purification device, the engine operating point Q is changed to a high-speed and low-torque side capable of self-renewing the exhaust gas purification device, and a change gear ratio of the continuously variable transmission is changed and regulated in such a manner that a vehicle speed V of the travel machine body is not changed.

Abstract: A transmission system for vehicle transmission mechanism (B) having a low speed hydraulic clutch (CL) and a high speed hydraulic clutch (CH) as a wet multi-disk clutch for transmission, wherein both the low speed hydraulic clutch (CL) and the high speed hydraulic clutch (CH) are disengaged so as to disconnect a transmission of an engine power to the transmission system, namely, so as to bring a main clutch into off condition, a dry clutch device (A) is installed on the upstream side of transmission of the transmission mechanism as a corotation prevention mechanism, only the low speed hydraulic clutch (CL) of large capacity is used as an inching clutch to bring the main clutch into a partial engaged condition when the main clutch is moved to on or off in the transmission mechanism (B) and, when the main clutch is operated from off to on with a shift lever (91) set at a high speed position, hydraulic pressure control is performed so that the high speed hydraulic clutch (CH) is brought into off condition and the