Operating method for a hybrid vehicle

• US 5,492,190 A
• Filed: 05/14/1993
• Issued: 02/20/1996
• Est. Priority Date: 05/15/1992
• Status: Expired due to Term

• Current Assignee: Mitsubishi Jidosha Kogyo Kabushiki Kaisha
• Original Assignee: Mitsubishi Jidosha Kogyo Kabushiki Kaisha
• Inventors: Yoshida, Masato
• Primary Examiner(s): Focarino, Margaret A.
• Assistant Examiner(s): Mattix, Carla
• Application Number:
  US08/060,991
• Time in Patent Office: 1,012 Days
• Field of Search: 180/65.1, 180/65.2, 180/65.3, 180/65.4, 180/309, 60/294, 60/300, 60/302, 60/303, 290/16, 290/17, 290/45, 290/50
• US Class Current: 180/65.245
• CPC Class Codes: B60K 2006/268 Electric drive motor starts the engine, i.e. used as starter motor
• CPC Class Codes: B60K 6/28 characterised by the electric energy storing means, e.g. batteries or capacitors
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60L 2240/445 Temperature
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: B60W 2510/0676 Engine temperature
• CPC Class Codes: B60W 2510/068 Engine exhaust temperature
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 30/194 related to low temperature conditions, e.g. high viscosity of hydraulic fluid
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y10S 903/907 Electricity storage, e.g. battery, capacitor

Abstract

An operating method for a hybrid vehicle which has an electric motor for driving the vehicle and an internal combustion engine for power generation. Upon completion of the activation of a catalyst, the engine is operated in warm-up mode with a small throttle valve opening, and when the output of a water temperature gauge thereafter reaches a predetermined value and the warm-up operation has completed, the engine is operated with a large throttle valve opening for the power generation. Thus, the hybrid vehicle can enjoy improved exhaust gas characteristics and increased cruising range and power performances. If it is determined that the storage amount of a battery is smaller than a predetermined storage amount when a starter key is so operated as to stop the vehicle, an alarm lamp is lighted, thus informing the driver of engine operation, and the engine operation is continued until the predetermined battery storage amount is reached or a predetermine time elapses from the start of the engine operation, whereby the battery is reliably charged. Accordingly, the battery can be reliably charged with power necessary to start the vehicle, and the cruising range and power performances of the vehicle are improved.

Claims

1. An operating method for a hybrid car which has an electric motor for driving the vehicle, a battery for supplying electric power to the electric motor, a generator for charging the battery, an internal combustion engine operatively isolated from the electric motor and used to drive the generator, a starter for starting the internal combustion engine, and an exhaust gas purifier, said method comprising the steps of:

determining by a controller whether drive of the internal combustion engine is requested;

detecting the temperature of an exhaust purifying catalyst of the exhaust gas purifier by means of a catalyst temperature sensor;

determining whether the detected temperature of the catalyst is lower than a predetermined value; and

executing a series of steps under the control of the controller when it is determined that the drive of the engine is requested and that the temperature of the catalyst is lower than the predetermined value,

said series of steps including;

stopping the internal combustion engine;

supplying electric power to an electric heater for heating the catalyst, thereby heating the electric heater; and

starting the internal combustion engine by the starter when the temperature of the catalyst becomes higher than the predetermined value.

2. An operating method for a hybrid car according to claim 1, wherein the internal combustion engine is operated in an operating condition in which an amount of fuel consumed by the internal combustion engine is small.

3. An operating method for a hybrid car according to claim 1, wherein said battery comprises a vehicle drive battery for supplying electric power to the electric motor and a heater battery for supplying electric power to said electric heater.

4. An operating method for a hybrid vehicle which has an electric motor for driving the vehicle, a battery for supplying electric power to the electric motor, a generator for charging the battery, an internal combustion engine operatively isolated from the electric motor and used to drive the generator, a starter for starting the internal combustion engine, and an exhaust gas purifier, said method comprising the steps of:

determining by a controller whether drive of the internal combustion engine is requested;

detecting the temperature of an exhaust purifying catalyst of the exhaust gas purifier by a catalyst temperature sensor;

determining whether the detected temperature of the catalyst is lower than a predetermined value; and

executing a series of steps under the control of the controller when it is determined that the drive of the engine is requested and that the temperature of the catalyst is lower than the predetermined value,

said series of steps including;

stopping the internal combustion engine;

supplying electric power to an electric heater for heating the catalyst, thereby heating the electric heater;

starting the internal combustion engine by the starter when the temperature of the catalyst becomes higher than the predetermined value;

determining whether the internal combustion engine has warmed up; and

wherein power generation of the generator by the internal combustion engine is started when it is determined that the internal combustion engine has warmed up.

5. An operating method for a hybrid vehicle according to claim 4, wherein said step for determining further comprises the substep of comparing a coolant temperature of the internal combustion engine with a second predetermined value to determine whether the internal combustion engine has warmed up.

6. A system for operating a hybrid car having an electric motor for driving the hybrid car comprising:

a battery for supplying electric power to the electric motor;

a generator for charging said battery;

an internal combustion engine operatively isolated from the electric motor for driving said generator;

a starter for starting said internal combustion engine;

an exhaust gas purifier;

a catalyst temperature sensor for detecting the temperature of an exhaust purifying catalyst of said exhaust gas purifier;

an electric heater for heating said exhaust purifying catalyst; and

a controller for determining whether a drive of said internal combustion engine is requested and determining whether the temperature detected by said catalyst temperature sensor is lower than a predetermined value, said controller stops said internal combustion engine, supplies electric power to said electric heater when the drive of said internal combustion engine is requested and the temperature of said exhaust purifying catalyst is lower than said predetermined value and starts said internal combustion engine by said starter when the drive of said internal combustion engine is requested and the temperature of said exhaust purifying catalyst becomes higher than said predetermined value.

7. A system for operating a hybrid car according to claim 6, wherein said internal combustion engine is operated in an operating condition in which an amount of fuel consumed by said internal combustion engine is small.

8. A system for operating a hybrid car according to claim 6, wherein said battery comprises a vehicle drive battery for supplying electric power to the electric motor and a heater battery for supplying electric power to said electric heater.

9. A system for operating a hybrid car having an electric motor for driving the hybrid car, comprising:

a battery for supplying electric power to the electric motor;

a generator for charging said battery;

an internal combustion engine operatively isolated from the electric motor for driving said generator;

a starter for starting said internal combustion engine;

an exhaust gas purifier;

a catalyst temperature sensor for detecting the temperature of an exhaust purifying catalyst of said exhaust gas purifier;

an electric heater for heating said exhaust purifying catalyst; and

a controller for determining whether a drive of said internal combustion engine is requested and determining whether the temperature detected by said catalyst temperature sensor is lower than a predetermined value, said controller stops said internal combustion engine, supplies electric power to said electric heater when the drive of said internal combustion engine is requested and the temperature of said exhaust purifying catalyst is lower than said predetermined value and starts said internal combustion engine by said starter when the drive of said internal combustion engine is requested and the temperature of said exhaust purifying catalyst becomes higher than said predetermined value, determines whether said internal combustion engine has warmed up, and

starts power generation of said generator by said internal combustion engine, when said controller determines that said internal combustion engine has warmed up.

10. A system for operating a hybrid car according to claim 9, wherein said controller compares a coolant temperature of said internal combustion engine with a second predetermined value to determine said warm up of said internal combustion engine.