Estimated torque calculation device of internal combustion engine and method thereof

Abstract

An ECU executes the step S100 of detecting an intake air amount QA and an ignition timing IT, the step S200 of calculating an estimated engine torque TE from QA and IT, the step S300 of detecting the engine rotation speed NE and the turbine rotation speed NT, the step S400 of calculating the speed ratio E of the torque converter 210, the step S500 of calculating a torque capacity C from the speed ratio, the step S600 of calculating a reference torque TP(0) from the torque capacity C, the step S700 correcting the reference torque TP(0) into TP based on a map, the step S900 setting TE as the estimated engine torque if TP is greater than TE, and the step S1000 setting TP as the estimated engine torque if TP is not greater than TE.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and further objects, features and advantages of the invention will become apparent from the following description of preferred embodiments with reference to the accompanying drawings, wherein like numerals are used to represent like elements and wherein:

FIG. 1 is a diagram showing a power train of a vehicle to which a estimated torque calculation device of an internal combustion engine in accordance with an embodiment of the invention is applied;

FIG. 2 is a schematic construction diagram of an internal combustion engine;

FIG. 3 is a control block diagram of a power train;

FIG. 4 is a diagram showing characteristic curves of a torque converter;

FIG. 5 is a diagram showing relationships between the engine rotation speed NE and the pump torque TP;

FIG. 6 is a block diagram of the estimated torque calculation device of the internal combustion engine in accordance with the embodiment;

FIG. 7 is a flowchart showing a control structure of a program executed by an ECU that is the estimated torque calculation device of the internal combustion engine in accordance with the embodiment;

FIG. 8 is a view showing a correction coefficient K(1) map; and

FIG. 9 is a view showing a correction coefficient K(2) map.

Claims

1. An estimated torque calculation device that calculates an estimated torque of an internal combustion engine, comprising: a first torque calculation portion that calculates an output torque of the internal combustion engine as a first output torque based on a load of the internal combustion engine;a second torque calculation portion that calculates the output torque of the internal combustion engine as a second output torque based on a map in which a rotation speed of the internal combustion engine is a parameter;a numerical value calculation portion that calculates a numerical value based on a characteristic of a torque converter connected to the internal combustion engine; anda setting portion that sets one of the first output torque and the second output torque as the estimated torque based on the numerical value.

2. The estimated torque calculation device according to claim 1, wherein the first torque calculation portion calculates the first output torque based on an intake air amount and an ignition timing of the internal combustion engine.

3. The estimated torque calculation device according to claim 1, wherein the second torque calculation portion calculates the second output torque based on a map in which the rotation speed of the internal combustion engine and a temperature of the internal combustion engine are parameters.

4. The estimated torque calculation device according to claim 1, wherein the second torque calculation portion calculates the second output torque based on a map in which the rotation speed of the internal combustion engine and a temperature of a working oil of an automatic transmission connected to the internal combustion engine via the torque converter are parameters.

5. The estimated torque calculation device according to claim, 1, wherein the second torque calculation portion calculates the second output torque based on a map in which the rotation speed of the internal combustion engine and a temperature of the internal combustion engine are parameters, and a map in which the rotation speed of the internal combustion engine and a temperature of a working oil of an automatic transmission connected to the internal combustion engine via the torque converter are parameters.

6. The estimated torque calculation device according to claim 1, wherein the numerical value calculation portion calculates a pump torque rotating an input shaft of the torque converter based on a torque capacity of the torque converter and the rotation speed of the internal combustion engine.

7. The estimated torque calculation device according to claim 6, wherein the setting portion compares the pump torque and the first output torque, and wherein if the pump torque is greater, the setting portion sets the first output torque as the estimated torque, and wherein if the pump torque is equal to or less than the first output torque, the setting portion sets the second output torque as the estimated torque.

8. The estimated torque calculation device according to claim 2, wherein the intake air amount is detected by an air flow meter.

9. The estimated torque calculation device according to claim 2, wherein the intake air amount is detected based on a throttle opening degree.

10. An estimated torque calculation device that calculates an estimated torque of an internal combustion engine, comprising: a first torque calculation portion that calculates an output torque of the internal combustion engine as a first output torque based on a load of the internal combustion engine;a second torque calculation portion that calculates the output torque of the internal combustion engine as a second output torque based on a map in which a rotation speed of the internal combustion engine is a parameter; anda setting portion that sets one of the first output torque and the second output torque as the estimated torque based on a state of operation of the internal combustion engine.

11. The estimated torque calculation device according to claim 10, further comprising a numerical value calculation portion that calculates a numerical value based on a characteristic of a torque converter connected to the internal combustion engine, wherein the setting portion sets one of the first output torque and the second output torque as the estimated torque based on the numerical value.

12. The estimated torque calculation device according to claim 10, wherein the setting portion sets one of the first output torque and the second output torque as the estimated torque based on an output rotation speed of the internal combustion engine.

13. The estimated torque calculation device according to claim 10, wherein the setting portion sets one of the first output torque and the second output torque as the estimated torque based on a throttle opening degree.

14. A estimated torque calculation method that calculates an estimated torque of an internal combustion engine, comprising: calculating an output torque of the internal combustion engine as a first output torque based on a load of the internal combustion engine;calculating the output torque of the internal combustion engine as a second output torque based on a map in which a rotation speed of the internal combustion engine is a parameter;calculating a numerical value based on a characteristic of a torque converter connected to the internal combustion engine; andsetting one of the first output torque and the second output torque as the estimated torque based on the numerical value.

15. The estimated torque calculation method according to claim 14, wherein the first output torque is calculated based on an intake air amount and an ignition timing of the internal combustion engine.

16. The estimated torque calculation method according to claim 14, wherein the second output torque is calculated based on a map in which the rotation speed of the internal combustion engine and a temperature of the internal combustion engine are parameters.

17. The estimated torque calculation method according to claim 14, wherein the second output torque is calculated based on a map in which the rotation speed of the internal combustion engine and a temperature of a working oil of an automatic transmission connected to the internal combustion engine via the torque converter are parameters.

18. The estimated torque calculation method according to claim 14, wherein the second output torque is calculated based on a map in which the rotation speed of the internal combustion engine and a temperature of the internal combustion engine are parameters, and a map in which the rotation speed of the internal combustion engine and a temperature of a working oil of an automatic transmission connected to the internal combustion engine via the torque converter are parameters.

19. The estimated torque calculation method according to claim 14, wherein a pump torque for rotating an input shaft of the torque converter is calculated based on a torque capacity of the torque converter and the rotation speed of the internal combustion engine.

20. The estimated torque calculation according to claim 19, wherein the pump torque and the first output torque are compared, and wherein if the pump torque is greater, the first output torque is set as the estimated torque, and wherein if the pump torque is equal to or less than the first output torque, the second output torque is set as the estimated torque.