CURVE OF MAXIMUM ALLOWABLE ENGINE TORQUE FOR CONTROLLING A COMBUSTION ENGINE

• US 20120277974A1
• Filed: 09/11/2009
• Published: 11/01/2012
• Est. Priority Date: 09/11/2009
• Status: Abandoned Application

• Current Assignee: Volvo Lastvagnar AB (Volvo AB)
• Original Assignee: Volvo Lastvagnar AB (Volvo AB)
• Inventors: Hedman, Anders, Sundin, Lars
• Application Number:
  US13/395,300
• Publication Number:
  US 20120277974A1
• Time in Patent Office: Days
• US Class Current: 701/102
• CPC Class Codes: B60W 30/1882 characterised by the working point of the engine, e.g. by using engine output chart
• CPC Class Codes: F02D 2250/26 by applying a torque limit
• CPC Class Codes: F02D 31/006 for maximum speed control
• CPC Class Codes: F02D 41/0007 for control of turbo-charged or super-charged engines control of the pumps per se F02B37/12
• CPC Class Codes: F02D 41/1497 With detection of the mechanical response of the engine
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A curve of maximum allowable engine torque as a function of engine rotational speed for controlling a combustion engine is provided, where a combustion engine control unit is arranged to control output torque and engine rotational speed as not to exceed the curve, and where the curve is defined by a torque build up range (n0 to ni), constant power range (n2 to 113) and a torque ramp down range (n3 to n4). The torque ramp down range is defined so that the engine rotational speed at high engine power is reduced, while high engine rotational speeds are allowed at low engine power.

Claims

1. A combustion engine control unit arranged to control output torque and engine rotational speed so as to never exceed a curve of maximum allowable engine torque as a function of engine rotational speed for controlling a combustion engine, where the curve is defined by at least a torque build up range (n0 to n1), constant power range (n2 to n3) and a torque ramp down range (n3 to n4), wherein the torque ramp down range is defined so that the engine rotational speed at high engine power is reduced, while high engine rotational speeds are allowed at low engine power, and where one or more components in a powertrain of which the engine is a part are adapted in order to provide the curve.

2. A control unit as in claim 1, wherein high engine power is defined as above 50% of the maximum engine power and low engine power is defined as below 50% of the maximum engine power.

3. A control unit as in claim 1, wherein a difference between maximum engine rotational speeds at 50% and 75% of maximum engine power is larger than 150 rpm.

4. A control unit as in claim 3, wherein the maximum engine rotational speed at 50% of maximum engine power (nmax50%) is less than 2300 rpm.

5. A control unit as in claim 1, wherein the maximum engine rotational speed at 50% of maximum engine power (nmax50%) is larger than 1.2 multiplied by the maximum engine rotational speed at 95% of maximum engine power (nmax95%).

6. A control unit as in claim 4, wherein at maximum allowable engine rotational speed (n4) and 0% of maximum engine p01.,er the difference between the maximum allowable engine rotational speed and engine rotational speed at 50% of maximum engine power (nmax50%) is larger than 100 rpm.

7. A control unit as in claim 1, wherein the combustion engine is mated to a power-interrupting automatic transmission.

8. A control unit as in claim 1, wherein the combustion engine comprises a supercharging arrangement of the turbocompound-type.