公开(公告)号：JPH02227315A

公开(公告)日：1990-09-10

申请号：JP34499789

申请日：1989-12-28

Applicant: WEBASTO AG FAHRZEUGTECHNIK

Inventor： PEETAA KOTSUKU ,  PEETAA BAASU ,  FURANTSU NOIMEIYAA ,  GEORUGU BATSUHARU

IPC: B60H1/03

Abstract: PURPOSE: To enhance engine preheating performance and indoor heating performance by circulating a coolant through an entire coolant circulation path up to a first predetermined temperature, circulating the coolant between the intake and outlet of a heating device at temperatures equal to or higher than the first temperature and up to a second temperature, and then gradually returning the coolant to circulation through all circulation paths. CONSTITUTION: When a fuel-operated heating device 7 is turned on, a bypass line 10 is closed by a control valve 11. A coolant is circulated within an engine 2, the heating device 7, and a vehicle heater 4 as long as the temperature detected by a temperature sensor is not higher than a first temperature which is about 30 deg.C at a maximum. Until the coolant temperature exceeding the first temperature has reached a second temperature of about 70 to 80 deg.C, the control valve 11 is opened to allow a large amount of coolant to flow through the bypass line 10 to reduce the amount of coolant passing through the heating device 7 so as to increase heating rate. After reaching the second temperature, the control valve 11 is gradually closed to return the coolant to circulation through all circulation paths. Engine preheating performance and heating performance can be enhanced by this constitution.