| 摘要 |
PURPOSE:To enlarge the limit of knocking to aim at enhancing engine torque, by cooling cooling water in an auxiliary cooling line system with the use of an auxiliary cooling medium passage when the opening degree of a throttle exceeds a predetermined value upon operation of an air-conditioning system to locally cool the end gas zone of a combustion chamber. CONSTITUTION:When the temperature of a passenger's compartment reaches a predetermined value so that a temperature switch 25 engages an electromagnetic clutch 27, a compressor 13 is driven by an engine body 1 through a belt 12 to establish an air-conditioning operation. In this time stage when the opening degree of a throttle exceeds a predetermined value and therefore a throttle switch 24 is turned on, a relay 29 is turned on to open a solenoid valve 19. Accordingly, a part of cooling medium in a main cooling medium system 18 is branched into an auxiliary cooling medium passage 23, then is introduced into an evaporator 22 to be evaporated after pressure reduction by an expansion valve 20, and is thereafter merged into the main cooling medium at the inlet port of the compressor 13. At this time, since cooling water in a cooling water tank 7 flows into a separate cooling water passage 10, the end gas zone of a combustion chamber may be concentratedly cooled. |
