Motor Vehicle Control Method of Internal Combustion Engine

• US 20070255485A1
• Filed: 09/17/2004
• Published: 11/01/2007
• Est. Priority Date: 09/17/2004
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Kaita, Keiji
• Granted Patent: US 7,430,469 B2
• Time in Patent Office: Days
• US Class Current: 701/102
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 1/003 to auxiliary motors, e.g. for pumps, compressors
• CPC Class Codes: B60L 1/02 to electric heating circuits
• CPC Class Codes: B60L 2240/34 Cabin temperature
• CPC Class Codes: B60L 2240/44 related to combustion engines
• CPC Class Codes: B60L 2240/445 Temperature
• CPC Class Codes: B60L 2240/662 Temperature
• CPC Class Codes: B60L 2260/22 Standstill, e.g. zero speed
• CPC Class Codes: B60L 2260/26 Transition between different drive modes
• CPC Class Codes: B60L 2260/28 Four wheel or all wheel drive
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• 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 10/24 including control of energy storage means
• 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 2510/0671 Engine manifold pressure
• CPC Class Codes: B60W 2510/0676 Engine temperature
• CPC Class Codes: B60W 30/192 Mitigating problems related to power-up or power-down of the driveline, e.g. start-up of a cold engine
• CPC Class Codes: F02D 2200/0406 Intake manifold pressure
• CPC Class Codes: F02D 2200/0414 Air temperature
• CPC Class Codes: F02D 2250/41 : Control to generate negative pressure in the intake manifold, e.g. for fuel vapor purging or brake booster
• CPC Class Codes: F02D 41/003 : Adding fuel vapours, e.g. drawn from engine fuel reservoir
• CPC Class Codes: F02D 41/0055 : Special engine operating conditions, e.g. for regeneration of exhaust gas treatment apparatus
• CPC Class Codes: F02D 41/021 : Introducing corrections for particular conditions exterior to the engine conjoint control of vehicle sub-units for propelling the vehicle B60W30/18
• CPC Class Codes: F02D 41/068 : for warming-up
• CPC Class Codes: F02M 25/0818 : having means for pressurising the evaporative emission space
• CPC Class Codes: F02M 25/0827 : by monitoring engine running conditions
• 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: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 90/16 : Information or communication technologies improving the operation of electric vehicles

Abstract

In a motor vehicle of the invention, when an intake air temperature Ta is not lower than a preset reference temperature Tref, warm-up drive control selectively uses an evaporated fuel processing acceleration operation curve, which gives a high level of a negative pressure in an intake manifold, to set a target drive point of an engine and controls the operation of the engine. This ensures good emission of the engine. When the intake air temperature Ta is lower than the preset reference temperature Tref and when the setting of a heating demand Hq requires heating, on the other hand, the warm-up drive control increases an EGR quantity from an ordinary level and switches over an operation mode of a cooling system for the engine to a warm-up circulation mode for making the flow of a cooling medium bypass a radiator. This introduces a greater amount of heat of exhaust into a heat exchanger to enable quick supply of the warm air to a passenger compartment. The warm-up drive control selectively uses a negative pressure reduction operation curve, which gives a lower level of the negative pressure in the intake manifold than the level of the negative pressure set on the evaporated fuel processing acceleration operation curve, to set the target drive point of the engine and controls the operation of the engine. This enhances the operation efficiency of the engine and improves the fuel economy during the warm-up time of the engine.

Claims

1. A motor vehicle equipped with an internal combustion engine as a power source, the motor vehicle comprising:

an evaporated fuel processing system that adsorbs evaporated fuel in a fuel tank, which stores a fuel to be supplied to the internal combustion engine, and introduces the adsorbed evaporated fuel into an air intake system of the internal combustion engine by means of a negative pressure in the air intake system, with a view to processing the evaporated fuel;

a heating system that utilizes the internal combustion engine as a heat source to heat a passenger compartment;

a low temperature state identification module that identifies whether the motor vehicle is in a specific low temperature state; and

a control module that, upon identification of a non-specific low temperature state by the low temperature state identification module, performs evaporated fuel processing acceleration control prior to negative pressure reduction control and, upon identification of the specific low temperature state by the low temperature state identification module, performs the negative pressure reduction control prior to the evaporated fuel processing acceleration control,

where the evaporated fuel processing acceleration control regulates operation of the internal combustion engine with setting a high level of the negative pressure in the air intake system for acceleration of the processing of the evaporated fuel by the evaporated fuel processing system, and

the negative pressure reduction control regulates the operation of the internal combustion engine with setting a lower level of the negative pressure in the air intake system than the level of the negative pressure set in the evaporated fuel processing acceleration control.

2. The motor vehicle in accordance with claim 1, wherein the control module performs the negative pressure reduction control upon identification of the specific low temperature state during a warm-up time of the internal combustion engine.

3. The motor vehicle in accordance with claim 1, wherein the negative pressure reduction control performed by the control module upon identification of the specific low temperature state regulates the operation of the internal combustion engine with setting a greater throttle opening than a throttle opening set in the evaporated fuel processing acceleration control.

4. The motor vehicle in accordance with claim 1, wherein the negative pressure reduction control performed by the control module upon identification of the specific low temperature state regulates the operation of the internal combustion engine with setting a lower rotation speed of the internal combustion engine than a rotation speed of the internal combustion engine set in the evaporated fuel processing acceleration control.

5. The motor vehicle in accordance with claim 1, wherein the negative pressure reduction control performed by the control module upon identification of the specific low temperature state regulates the operation of the internal combustion engine with setting a higher torque of the internal combustion engine than a torque of the internal combustion engine set in the evaporated fuel processing acceleration control.

6. The motor vehicle in accordance with claim 1, the motor vehicle further including:

a temperature measurement unit that measures at least one of an intake air temperature, a fuel temperature, a passenger compartment temperature, and an outside air temperature,

wherein the low temperature state identification module identifies whether the motor vehicle is in the specific low temperature state, based on a measurement result of at least one of the intake air temperature, the fuel temperature, the passenger compartment temperature, and the outside air temperature by the temperature measurement unit.

7. The motor vehicle in accordance with claim 1, wherein the low temperature state identification module identifies whether the motor vehicle is in the specific low temperature state, based on the presence or the absence of a heating requirement for heating the passenger compartment by the heating system.

8. The motor vehicle in accordance with claim 1, the motor vehicle further including:

an exhaust recirculation system that recirculates at least part of exhaust from the internal combustion engine into the air intake system of the internal combustion engine,

wherein the negative pressure reduction control performed by the control module upon identification of the specific low temperature state regulates the operation of the internal combustion engine with setting a greater recirculation rate of the exhaust into the air intake system by the exhaust recirculation system than a recirculation rate of the exhaust set in the evaporated fuel processing acceleration control.

9. The motor vehicle in accordance with claim 8, the motor vehicle further having:

a cooling and warm-up accelerating system that includes a heat exchanger to cool down a cooling medium through heat exchange with the outside air, the cooling and warm-up accelerating system switching over a cooling medium flow path between ordinary circulation of the cooling medium and bypass circulation of the cooling medium,

where the ordinary circulation makes the cooling medium flow through the heat exchanger, the internal combustion engine, and part of the exhaust recirculation system in this sequence to cool down the internal combustion engine and the part of the exhaust recirculation system, and

the bypass circulation makes the cooling medium bypass the heat exchanger and flow through only the internal combustion engine and the part of the exhaust recirculation system to accelerate warm-up of the internal combustion engine; and

a warm-up time control module that, upon identification of the non-specific low temperature state by the low temperature state identification module during a warm-up time of the internal combustion engine, controls the cooling and warm-up accelerating system to switch over the cooling medium flow path to the ordinary circulation and cool down the internal combustion engine and the part of the exhaust recirculation system and, upon identification of the specific low temperature state by the low temperature state identification module during the warm-up time of the internal combustion engine, controls the cooling and warm-up accelerating system to switch over the cooling medium flow path to the bypass circulation and accelerate the warm-up of the internal combustion engine.

10. The-motor vehicle in accordance with claim 1, the motor vehicle further having:

a variable speed change transmission mechanism that transmits power of the internal combustion engine to a predetermined axle after variable speed change.

11. The motor vehicle in accordance with claim 1, the motor vehicle further including:

a generator that has power generation ability of utilizing power of the internal combustion engine to generate electric power; and

a motor that is driven with the electric power generated by the generator.

12. The motor vehicle in accordance with claim 11, the motor vehicle further including:

a three shaft-type power input output structure that is linked to three shafts, an output shaft of the internal combustion engine, a driveshaft linked with a predetermined axle, and a rotating shaft of the generator, and inputs and outputs power from and to a residual one shaft based on powers input from and output to any two shafts among the three shafts,

where the motor is linked with either the predetermined axle or a different axle.

13. The motor vehicle in accordance with claim 11, wherein the generator is a pair-rotor motor generator that has a first rotor connected to an output shaft of the internal combustion engine and a second rotor connected to a driveshaft linked with a predetermined axle and is driven to relatively rotate through electromagnetic interaction between the first rotor and the second rotor, and

the motor is linked with either the predetermined axle or a different axle.

14. A control method of an internal combustion engine mounted on a motor vehicle, the motor vehicle having:

the internal combustion engine as a power source;

an evaporated fuel processing system that adsorbs evaporated fuel in a fuel tank, which stores a fuel to be supplied to the internal combustion engine, and introduces the adsorbed evaporated fuel into an air intake system of the internal combustion engine by means of a negative pressure in the air intake system, with a view to processing the evaporated fuel; and

a heating system that utilizes the internal combustion engine as a heat source to heat a passenger compartment,

the control method comprising;

identifying whether the motor vehicle is in a specific low temperature state; and

upon identification of a non-specific low temperature state, performing evaporated fuel processing acceleration control prior to negative pressure reduction control and, upon identification of the specific low temperature state, performing the negative pressure reduction control prior to the evaporated fuel processing acceleration control,

where the evaporated fuel processing acceleration control regulates operation of the internal combustion engine with setting a high level of the negative pressure in the air intake system for acceleration of the processing of the evaporated fuel by the evaporated fuel processing system, and

the negative pressure reduction control regulates the operation of the internal combustion engine with setting a lower level of the negative pressure in the air intake system than the level of the negative pressure set in the evaporated fuel processing acceleration control.