| 摘要 |
An auxiliary air flow control system for an internal combustion engine, comprises an auxiliary air passage arranged parallel to an intake-air passage and bypassing a throttle valve disposed in the intake-air passage for diverting a part of intake air from an upstream side of the throttle valve to a downstream side of the throttle valve, an auxiliary air flow control valve disposed in the auxiliary air passage and responsive to operating conditions of the engine for producing therethrough a controlled flow rate of the auxiliary air, and an auxiliary air flow constricting valve sensitive to an engine coolant temperature for constricting the controlled flow rate of the auxiliary air from the auxiliary air flow control valve. The auxiliary air flow constricting vane has a substantially V-shaped coolant-temperature versus auxiliary air-flow constriction characteristic. According to this characteristic, the flow rate of auxiliary air is gradually decreased owing to a coolant-temperature rise when the coolant temperature is below a first predetermined temperature, and gradually increased owing to the temperature rise when the coolant temperature is below a second predetermined temperature, and held constant within a predetermined temperature range of the first and second predetermined temperatures.
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