| 摘要 |
PURPOSE:To provide a straightforward travel control circuit for vehicle adapted to control the pressure inside a third circuit system in corresponding relation to the operational condition and capable of minimizing the energy loss. CONSTITUTION:A restrictor 38 is provided between a straightforward travel V of a third circuit system and a change-over valve 23 located at an upstream position therefrom while, on the other hand, a branch passage 39 is provided which makes communication between an upstream side of the restrictor 38 and a tank passage 10, the branch passage 39 being provided with a pressure change-over valve 40 subjected to change-over in corresponding relation to a change in the pressure difference between before and after the restrictor 38. Communication/interruption between the upstream side of the restrictor 38 and the tank passage 10 are changed over through the operation of the pressure change-over valve 40 changed over in corresponding relation to a rise in pressure inside the third circuit system and in corresponding relation to a change in the pressure difference between before and after the restrictor 38, so as to control the pressure inside the circuit. |
