Apparatus for controlling the idling speed of an internal combustion engine

• US 6,109,237 A
• Filed: 08/04/1999
• Issued: 08/29/2000
• Est. Priority Date: 02/04/1997
• Status: Expired due to Fees

• Current Assignee: Isad Electronic Systems GmbH & Co. KG
• Original Assignee: Isad Electronic Systems GmbH & Co. KG
• Inventors: Revermann, Klaus, Pels, Thomas, Zeyen, Klaus-Peter
• Primary Examiner(s): Kwon, John
• Application Number:
  US09/368,372
• Time in Patent Office: 391 Days
• Field of Search: 123/339.11, 123/339.19, 123/339.21, 123/339.16, 290/40 A
• US Class Current: 123/339.19
• CPC Class Codes: B60K 2006/268 Electric drive motor starts the engine, i.e. used as starter motor
• CPC Class Codes: B60K 6/485 Motor-assist type
• CPC Class Codes: B60L 2200/26 Rail 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 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 2710/0644 Engine speed
• CPC Class Codes: B60W 2710/065 Idle condition
• CPC Class Codes: F02D 41/083 taking into account engine load variation, e.g. air-conditionning
• CPC Class Codes: F02N 11/003 said electric motor being also used as a drive for auxiliaries, e.g. for driving transmission pumps or fuel pumps during engine stop
• CPC Class Codes: F02N 11/04 the motors being associated with current generators
• CPC Class Codes: F02N 11/0866 comprising several power sources, e.g. battery and capacitor or two batteries
• CPC Class Codes: H02P 2101/45 for motor vehicles, e.g. car alternators
• CPC Class Codes: H02P 9/107 for limiting effects of overloads
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility

Abstract

An apparatus for controlling an idling speed of an internal combustion engine is disclosed. The apparatus includes an electric machine operatively coupled to the internal combustion engine for applying a braking torque to the internal combustion engine to reduce the idling speed and for applying a driving torque to the internal combustion engine to increase the idling speed. It also includes a controller for controlling the electric machine. The controller is responsive to a load change to control the electric machine to apply one of a braking torque and a driving torque to the internal combustion engine to substantially maintain the idling speed at a predefined level.

Claims

1. An apparatus for controlling an idling speed of an internal combustion engine comprising:

a first control system for adjusting the idling speed of the internal combustion engine in response to a load change experienced by the internal combustion engine, the first control system having a first reaction time; and

a second control system for adjusting the idling speed of the internal combustion engine in response to the load change, the second control system having a second reaction time which is shorter than the first reaction time, the second control system further comprising;

an electric machine operatively coupled to the internal combustion engine for applying a braking torque to the internal combustion engine to reduce the idling speed and for applying a driving torque to the internal combustion engine to increase the idling speed;

an inverter for supplying power to the electric machine; and

a controller in communication with the inverter for controlling the electric machine, the controller being responsive to the load change to control the electric machine either to reduce a braking torque or apply a driving torque to the internal combustion engine to substantially maintain the idling speed at a predefined level until the first reaction time has expired.

2. An apparatus as defined in claim 1 wherein the apparatus is used in a vehicle, the inverter comprises an intermediate circuit having a first voltage level, the vehicle has an electrical system with a second voltage level;

and the first voltage level is higher than the second voltage level.

3. An apparatus as defined in claim 2 further comprising at least one energy storage device coupled to the intermediate circuit at the first voltage level.

4. An apparatus as defined in claim 3 wherein the electric machine can operate as a generator for developing power and a motor, and further comprising at least one power consumer arranged to receive power from the electric machine, wherein, when the power developed by the electric machine is reduced because the electric machine is adjusting the idling speed, the consumer is at least partially supplied with power from the at least one storage device.

5. An apparatus as defined in claim 3 wherein the electric machine can operate as a generator for developing power and a motor, wherein, when the electric machine operates as a motor, it is supplied with power from the at least one storage device.

6. An apparatus as defined in claim 3 wherein the electric machine can operate as a generator for developing power and a motor, wherein, when the electric machine operates as a generator, it supplies power to the at least one storage device.

7. An apparatus as defined in claim 1 wherein the internal combustion engine is operated at an optimum ignition point when idling.

8. An apparatus as defined in claim 1 further comprising a speed sensor for detecting the speed of the internal combustion engine, at least one of the first control system and the controller being in communication with the speed sensor.

9. An apparatus as defined in claim 1 further comprising a load sensor for detecting load changes, at least one of the first control system and the controller being in communication with the load sensor.

10. An apparatus as defined in claim 9 wherein the load sensor detects a load change before the load change occurs and the at least one of the first control system and the controller initiates adjustment of the idling speed before the load change effects the idling speed of the internal combustion engine.

11. An apparatus for controlling an idling speed of an internal combustion engine comprising:

a first control system for adjusting the idling speed of the internal combustion engine in response to a load change experienced by the internal combustion engine, the first control system having a first reaction time; and

a second control system for adjusting the idling speed of the internal combustion engine in response to the load change, the second control system having a second reaction time which is shorter than the first reaction time.