Starting control apparatus for internal combustion engine

• US 6,247,437 B1
• Filed: 09/09/1998
• Issued: 06/19/2001
• Est. Priority Date: 09/17/1997
• Status: Expired due to Term

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Yamaguchi, Katsuhiko, Hino, Seiji
• Primary Examiner(s): Dolinar, Andrew M.
• Application Number:
  US09/149,661
• Time in Patent Office: 1,014 Days
• Field of Search: 123/179.3, 123/179.4, 123/491, 290/38.R, 290/38.C, 607/06, 180/65.2
• US Class Current: 123/179.3
• CPC Class Codes: B60K 2006/268 Electric drive motor starts the engine, i.e. used as starter motor
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 15/20 for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2220/14 Synchronous machines
• CPC Class Codes: B60L 2220/52 Clutch motors
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 2240/445 Temperature
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/549 Current
• 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 10/08 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 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 20/40 : Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers power-up or power-down of the driveline B60W30/192
• CPC Class Codes: B60W 2510/0676 : Engine temperature
• CPC Class Codes: B60W 2710/086 : Power
• CPC Class Codes: B60W 30/194 : related to low temperature conditions, e.g. high viscosity of hydraulic fluid
• CPC Class Codes: B60W 50/0097 : Predicting future conditions
• CPC Class Codes: F02D 2200/503 : Battery correction, i.e. corrections as a function of the state of the battery, its output or its type
• CPC Class Codes: F02N 11/08 : Circuits or control means specially adapted for starting of engines
• CPC Class Codes: F02N 11/0848 : with means for detecting successful engine start, e.g. to stop starter actuation
• CPC Class Codes: F02N 2200/023 : Engine temperature
• CPC Class Codes: F02N 2200/042 : Starter torque
• CPC Class Codes: F02N 2300/104 : Control of the starter motor torque
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• 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: Y10S 903/903 : having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/905 : Combustion engine
• CPC Class Codes: Y10S 903/906 : Motor or generator
• CPC Class Codes: Y10S 903/917 : with transmission for changing gear ratio
• CPC Class Codes: Y10S 903/951 : Assembly or relative location of components

Abstract

When a first motor MG1 cranks and starts an engine 150 that is in the cold, the revolving speed of the engine does not increase quickly 150. It is accordingly required to control the first motor MG1, in order to prevent electric power 194 stored in a battery from being wasted. A starting control apparatus does not cause the first motor MG1 to output a torque corresponding to a difference between a target revolving speed N* and an actual revolving speed Ne of the engine 150, but gradually increases a target torque STG by the open-loop control and restricts the magnitude of the target torque STG to a preset maximum torque STGMAX, which depends upon a cooling water temperature Tw of the engine 150. When the engine 150 is cold, the high viscosity of lubricant causes the revolving speed of the engine 150 not to quickly increase in response to the high target torque set to the first motor MG1. In this case, the maximum of the target torque is restricted to a smaller value, so as to prevent the electric power stored in the battery 194 from being wasted. The injection allowable revolving speed, at which the fuel injection to the engine 150 is allowed to start, is also set equal to a small value. This causes the engine 150 to start self driving at an earlier timing, thereby saving the electric power consumed by the first motor MG1.

Claims

1. A starting control apparatus for an internal combustion engine, that rotates said internal combustion engine, which internal combustion engine is connected via a damper with a rotating shaft of a motor driven by a battery, so as to start said internal combustion engine, said starting control apparatus comprising:

a startability detection unit that detects a parameter relating to startability of said internal combustion engine;

a device which is configured to determine a target output torque of the motor; and

an output torque restricting unit that restricts a maximum value of the target output torque of said motor for rotating said internal combustion engine to a smaller value in response to lower startability of said internal combustion engine specified from the parameter detected by said internal combustion engine startability detection unit.

2. The starting control apparatus in accordance with claim 1, said starting control apparatus further comprising:

a starting-time fuel supply control unit that starts a supply of fuel to said internal combustion engine at a lower revolving speed, in response to the lower startability.

3. The starting control apparatus in accordance with claim 1, wherein the parameter relating to the startability of said internal combustion engine correlates to temperature of said internal combustion engine.

4. The starting control apparatus in accordance with claim 1, said starting control apparatus further comprising:

a full combustion determination unit for determining that said internal combustion engine is in a state of full combustion, based on a driving condition of said internal combustion engine;

a time count unit for determining that a predetermined time period has elapsed since a start of cranking said internal combustion engine by said motor; and

a starting control discontinuance unit that cuts off a supply of electricity from said battery to said motor and immediately stops starting control of said internal combustion engine, when said full combustion determination unit determines that said internal combustion engine is not in the state of full combustion while said time count unit determines that the predetermined time period has elapsed.

5. The starting control apparatus in accordance with claim 4, wherein said full combustion determination unit comprises a torque detection unit that measures an actual output torque of said motor as the driving condition of said internal combustion engine, and wherein said full combustion determination unit determines that said internal combustion engine is in the state of full combustion when the actual output torque measured by said torque detection unit has a negative value.

6. The starting control apparatus in accordance with claim 4, said starting control apparatus further comprising:

a time period setting unit that sets a greater value to the predetermined time period, which is a target of the determination by said time count unit, in response to the lower startability of said internal combustion engine specified from the parameter.

7. The starting control apparatus in accordance with claim 4, said starting control apparatus further comprising:

an electric power estimation unit that estimates an amount of electric power suppliable from said battery; and

a unit that sets a greater value to the predetermined time period, which is a target of the determination by said time count unit, for the greater amount of estimated electric power.

8. The starting control apparatus in accordance with claim 7, wherein said electric power estimation unit comprises a unit that measures a temperature of said battery and a unit that corrects the estimated value of suppliable electric power to a larger value at the higher battery temperature.

9. The starting control apparatus in accordance with claim 4, said starting control apparatus further comprising:

an electric power integration unit that integrates electric power consumed by said battery since the start of cranking,

wherein said time count unit determines that the predetermined time period has elapsed when the integrated electric power reaches a preset reference value.

10. The starting control apparatus in accordance with claim 9, said starting control apparatus further comprising:

a battery temperature measuring unit that measures a temperature of said battery; and

a unit that corrects the preset reference value, which is used for the determination by said time count unit, to a smaller value at the lower battery temperature measured by said battery temperature detection unit.

11. The starting control apparatus in accordance with claim 1, said starting control apparatus further comprising:

a unit that adjusts an open-close timing of an air intake valve of said internal combustion engine, in order to lower an effective compression ratio of said internal combustion engine, at a time of starting said internal combustion engine.

12. A method of starting an internal combustion engine, which is connected via a damper with a rotating shaft of a motor driven by a battery, said method comprising the steps of:

(a) detecting a parameter relating to startability of said internal combustion engine;

(b) determining a target output torque of the motor; and

(c) restricting a maximum value of the target output torque of said motor for rotating said internal combustion engine to a smaller value in response to lower startability of said internal combustion engine specified from the parameter detected in step (a).

13. A starting control apparatus for a hybrid vehicle, which rotates an internal combustion engine in the hybrid vehicle that takes out power of said internal combustion engine in an electrical form and outputs power of a motor at least to drive a shaft of said vehicle, said starting control apparatus comprising:

a motor that cranks said internal combustion engine at a start of said internal combustion engine;

a starting-time fuel supply unit that controls a supply of fuel to said internal combustion engine, simultaneously with cranking of said internal combustion engine by said motor;

a startability detection unit that detects a parameter relating to startability of said internal combustion engine;

a device which is configured to determine a target output torque of the motor; and

an output torque restriction unit that restricts a maximum value of the target output torque of said motor for rotating said internal combustion engine to a smaller value at the time of cranking, in response to lower startability of said internal combustion engine specified from the parameter.

14. A starting control apparatus for an internal combustion engine, that rotates said internal combustion engine, which internal combustion engine is connected via a damper with a rotating shaft of a motor driven by a battery, so as to start said internal combustion engine, said starting control apparatus comprising:

a temperature sensor;

a device which is configured to determine a target output torque of the motor; and

an output torque restricting unit that restricts a maximum value of the target output torque of said motor for rotating said internal combustion engine to a smaller value in response to lower detected temperature.

15. A method of starting an internal combustion engine, which is connected via a damper with a rotating shaft of a motor driven by a battery, said method comprising the steps of:

(a) detecting a temperature related to a temperature of said internal combustion engine;

(b) determining a target output torque of the motor; and

(c) restricting a maximum value of the target output torque of said motor for rotating said internal combustion engine to a smaller value in response to lower startability of said internal combustion engine specified from the parameter detected in step (a).

16. A starting control apparatus for a hybrid vehicle, which rotates an internal combustion engine in the hybrid vehicle that takes out power of said internal combustion engine in an electrical form and outputs power of a motor at least to drive a shaft of said vehicle, said starting control apparatus comprising:

a motor that cranks said internal combustion engine at a start of said internal combustion engine;

a starting-time fuel supply unit that controls a supply of fuel to said internal combustion engine, simultaneously with cranking of said internal combustion engine by said motor;

a temperature sensor;

a device which is configured to determine a target output torque of the motor; and

an output torque restriction unit that restricts a maximum value of the target output torque of said motor for rotating said internal combustion engine to a smaller value at the time of cranking, in response to lower detected temperature.