Heating apparatus for vehicle

• US 5,852,995 A
• Filed: 09/24/1997
• Issued: 12/29/1998
• Est. Priority Date: 10/01/1996
• Status: Expired due to Term

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Aoki, Shinji, Morikawa, Toshio, Ito, Hajime
• Primary Examiner(s): Solis, Erick R.
• Application Number:
  US08/936,257
• Time in Patent Office: 461 Days
• Field of Search: 123/339.16, 123/339.17, 123/339.18, 123/142.5 R
• US Class Current: 123/339.16
• CPC Class Codes: B60H 1/038 from the cooling liquid of the propulsion plant and from a viscous fluid heater
• CPC Class Codes: F01P 2060/18 Heater
• CPC Class Codes: F01P 3/20 Cooling circuits not specific to a single part of engine or machine F01P3/22 takes precedence

Abstract

A viscous heater for heating cooling water for cooling a water cooled engine is provided in a cooling water circuit between the engine and a front heater core. Even if a viscous switch is turned on by a viscous ECU to heat a passenger compartment using the viscous heater, a viscous clutch is not immediately turned on when the engine is idling. That is, after a delay control time elapses after increasing an idling rotational speed of the engine to a target rotational speed, the viscous heater is turned on. The target rotational speed which is higher than a normal idling rotational speed is set in such a manner that the higher the cooling water temperature is, the lower the target rotational speed becomes. Thus, even if a large load is applied to the engine by operating the viscous heater when the engine is idling, it can improve fuel economy and prevent an engine stall.

Claims

1. A heating apparatus for heating a passenger compartment of a vehicle having a water-cooled engine, comprising:

a heating heat exchanger for heating said passenger compartment by performing heat-exchange between cooling water having cooled said water-cooled engine and air to be blown into said passenger compartment;

a heat-generating unit using a shearing force, said heat-generating unit including a rotor which rotates when a driving force is applied thereto and a heat-generating chamber for sealing therein viscous fluid which generates heat for heating said cooling water circulating between said engine and said heating heat exchanger when a shearing force generated by a rotational force of said rotor is applied to said viscous fluid;

a clutch unit for intermitting a transmission of the driving force from said engine to said rotor;

heating instruction means for giving an instruction for heating said cooling water by said heat-generating unit; and

a heating control unit which controls said clutch unit to transmit the driving force of said engine to said rotor after increasing a rotational speed of said engine when said heating instruction means gives the instruction for heating said cooling water, said heating control unit including means for detecting a temperature of said cooling water, said rotational speed of said engine being set to a first speed when said temperature of said cooling water is lower than predetermined temperature and said rotational speed of said engine being set to a second speed when said temperature of said cooling water is higher than the predetermined temperature, said second speed being lower than said first speed.

2. A heating apparatus according to claim 1, wherein:

said heating control unit includes driving state detection means for detecting a driving state of said engine; and

said heating control unit controls said clutch unit to transmit the driving force of said engine to said rotor after increasing an idling rotational speed of said engine when said driving state detected by said driving state detection means is idling.

3. A heating apparatus according to claim 1, wherein:

said heating control unit includes driving state detection means for detecting a driving state of said engine; and

said heating control unit controls said clutch unit to transmit the driving force of said engine to said rotor after a predetermined time has elapsed after increasing an idling rotational speed of said engine when said driving state detected by said driving state detection means is idling.

4. A heating apparatus according to claim 3, wherein said heating control unit controls said clutch unit to transmit the driving force of said engine to said rotor after a predetermined time has elapsed after increasing an idling rotational speed of said engine to a target rotational speed when said driving state detected by said driving state detection means is idling.

5. A heating apparatus according to claim 4, wherein

said rotational speed is set in such a manner that the larger said temperature of said cooling water is, the lower said rotational speed becomes.

6. A heating apparatus according to claim 4, wherein

said rotational speed is set to the maximum value when said temperature of said cooling water is less than a predetermined value.

7. A heating apparatus according to claim 1, wherein said second speed is decreased as the temperature of the cooling water is increased.

8. A heating apparatus for heating a passenger compartment of a vehicle having a water-cooled engine, comprising:

a heating heat exchanger for heating said passenger compartment by performing heat-exchange between cooling water having cooled said water-cooled engine and air to be blown into said passenger compartment;

a heat-generating unit using a shearing force, said heat-generating unit including a rotor which rotates when a driving force is applied thereto and a heat-generating chamber for sealing therein viscous fluid which generates heat for heating said cooling water circulating between said engine and said heating heat exchanger when a shearing force generated by a rotational force of said rotor is applied to said viscous fluid;

a driving force transmission unit for transmitting the driving force from said engine to said rotor;

shearing state switching means for switching a shearing state of the viscous fluid by the rotation of said rotor;

heating instruction means for giving an instruction for heating said cooling water by said heat-generating unit; and

a heating control unit which controls said shearing state switching means to apply a shearing force to the viscous fluid by the rotational force of said rotor after increasing a rotational speed of said engine when said heating instruction means gives the instruction for heating said cooling water, said heating control unit including means for detecting a temperature of said cooling water, said rotational speed of said engine being set to a first speed when said temperature of said cooling water is lower than predetermined temperature and said rotational speed of said engine being set to a second speed when said temperature of said cooling water is higher than the predetermined temperature, said second speed being lower than said first speed.

9. A heating apparatus according to claim 8, wherein:

said heating control unit includes driving state detection means for detecting a driving state of said engine; and

said heating control unit controls said shearing state switching means to apply the shearing force to the viscous fluid by the rotational force of said rotor after a predetermined time has elapsed after increasing an idling rotational speed of said engine to a target rotational speed when said driving state detected by said driving state detection means is idling.

10. A heating apparatus according to claim 9, wherein said second speed is decreased as the temperature of the cooling water is increased.

11. A heating apparatus according to claim 10, wherein:

said heating control unit includes driving state detection means for detecting a driving state of said engine; and

said heating control unit controls said clutch unit to transmit the driving force of said engine to said rotor after increasing an idling rotational speed of said engine when said driving state detected by said driving state detection means is idling.

12. A heating apparatus for heating a passenger compartment of a vehicle having a water-cooled engine, said heating apparatus comprising:

a heat exchanger for heating said passenger compartment by performing heat-exchange between cooling water having cooled said water-cooled engine and air to be blown into said passenger compartment;

a heat generating unit including a rotor which rotates within a chamber when a driving force from said engine is applied thereto, said chamber sealing therein viscous fluid which generates heat for heating said cooling water circulating between said engine and said heat exchanger when a shearing force generated by rotation of said rotor is applied to said viscous fluid;

a clutch unit for selectively transmitting said driving force from said engine to said rotor;

means for giving an instruction for heating said cooling water by said heating generating unit; and

a heating control unit which controls said clutch unit and said engine, said heating control engaging said clutch to transmit said driving force to said rotor after increasing a rotational speed of said engine to a predetermined speed, said predetermined speed being selected from a range of speeds between a minimum speed and a maximum speed.