Idle-up system during a power steering operation of a vehicle

An idle-up system in a vehicle provided with a power steering means including flapper valve means, said system comprising:

• an electrically operated pressure sensing means fluidly coupled to the flapper valve means for sensing a difference of pressures acting on one side and the other side of a piston in a power cylinder of the power steering means during a steering operation;
• an electromagnetic vacuum switching valve responsive to said pressure sensing means and having a vacuum opening communicating with a vacuum port of a carburetor of the engine through an intake vacuum line and an atmosphere opening and adapted to be, actuated by said pressure sensing means when said pressure sensing means detects a pressure difference across the piston to effect a switching operation between said vacuum opening and said atmosphere opening;
• a source of electric power electrically connected to said electromagnetic vacuum switching valve;
• a diaphragm-type actuating mechanism fluidly coupled to said vacuum switching valve and comprising a diaphragm chamber communicating with said vacuum opening of said vacuum switching valve via a vacuum line and means moveable with said diaphragm in response to the motion thereof;
• and
• interlocking means arranged between said means moveable with said diaphragm and a throttle valve of the carburetor, said interlocking means being operable to open said throttle valve by a predetermined extent in response to the vacuum communicating operation of said electromagnetic vacuum switching valve.