Engine torque-detecting method and an apparatus therefor

• US 6,332,352 B1
• Filed: 04/09/1997
• Issued: 12/25/2001
• Est. Priority Date: 03/08/1993
• Status: Expired due to Term

• Current Assignee: Yamaha Hatsudoki Kabushiki Kaisha (Yamaha Corporation)
• Original Assignee: Yamaha Hatsudoki Kabushiki Kaisha (Yamaha Corporation)
• Inventors: Sano, Taketoshi
• Primary Examiner(s): MCCALL, ERIC SCOTT
• Application Number:
  US08/833,767
• Time in Patent Office: 1,721 Days
• Field of Search: 73/115, 73/116, 73/117.3
• US Class Current: 73/114.15
• CPC Class Codes: G01L 3/00 Measuring torque, work, mechanical power, or mechanical efficiency, in general
• CPC Class Codes: G01L 3/245 by measuring and simultaneously multiplying pressure and velocity
• CPC Class Codes: G01M 15/08 by monitoring pressure in cylinders

Abstract

A method and apparatus for measuring the instantaneous torque of an engine by measuring the change in pressure in the combustion chamber at two crank angles. The crank angles are chosen to approximate the time when the change in pressure is the greatest and when the pressure is the greatest and the change in pressure is zero. These crank angles may be either determined by measuring the values or by approximating the crank angles at which the values will exist. In some instances, the torque is measured by summing the change in pressures during the time interval and in other methods the torque is measured by determining the pressure differences at the two crank angles.

Claims

1. A method for measuring output torque of an internal combustion engine during a single cycle of operation wherein the engine comprises a combustion chamber and an output shaft driven by combustion occurring in the combustion chamber, said method comprising the steps of taking a specific number of measurements of instantaneous pressure conditions directly in the combustion chamber only at spaced time intervals between two output shaft angles during only a portion of a complete cycle of operation and for less than the complete cycle and computing torque of the engine for the complete cycle from such specific number of separate instantaneous measurements.

2. The method as set forth in claim 1, wherein change in pressure in the combustion chamber is measured.

3. The method as set forth in claim 2, wherein torque is computed by summing the change in pressure during a time period between the two specific output shaft angles.

4. The method as set forth in claim 3, wherein one of the specific output shaft angles is the angle when change in pressure is greatest.

5. The method as set forth in claim 4, wherein the other specific output shaft angle is the output shaft angle where maximum pressure exists and rate of change of pressure is zero.

6. The method as set forth in claim 5, wherein one of the specific output shaft angles is computed from known data.

7. The method as set forth in claim 6, wherein the first occurring output shaft angle is the computed one.

8. The method as set forth in claim 7, wherein the computed angle is computed by determining speed of rotation of the output shaft.

9. The method as set forth in claim 8, wherein speed of rotation of the output shaft is measured by a sensor that provides a single pulse during one rotation of the shaft.

10. The method as set forth in claim 9, wherein speed is calculated by measuring angular rotational speed of the output shaft for less than one complete revolution by sensing change of the pulse and determining the angle which the shaft rotates for the pulse to change.

11. The method as set forth in claim 1, wherein one of the output shaft angles is the angle when change in pressure is the greatest.

12. The method as set forth in claim 11, wherein the other output shaft angle is the output shaft angle where maximum pressure exists and rate of change of pressure is zero.

13. The method as set forth in claim 12, wherein one of the output shaft angles is computed from known data.

14. The method as set forth in claim 13, wherein the first occurring output shaft angle is the computed one.

15. The method as set forth in claim 14, wherein the computed angle is computed by determining speed of rotation of the output shaft.

16. The method as set forth in claim 15, wherein speed of rotation of the output shaft is measured from a sensor that provides a single pulse during one rotation of the output shaft.

17. The method as set forth in claim 16, wherein the speed is calculated by measuring angular rotational speed of the output shaft for less than one complete revolution by sensing change of the pulse and determining the angle which the shaft rotates for the pulse to change.

18. The method as set forth in claim 1, wherein actual pressure in the combustion chamber is measured.

19. The method as set forth in claim 18, wherein the torque is determined by measuring differences in pressure in the combustion chamber at the two specific output shaft angles.

20. The method as set forth in claim 19, wherein the two specific output shaft angles are selected as an angle immediately before top dead center and another angle in the range of 10°

to 20°

after top dead center.

21. The method as set forth in claim 20, wherein the specific output shaft angles are varied depending upon speed of the engine.

22. The method as set forth in claim 21, wherein the engine is a spark ignited engine and spark timing is also varied with engine speed.

23. The method as set forth in claim 21, wherein speed of rotation of the output shaft is measured by a sensor that provides a single pulse during one rotation of the shaft.

24. The method as set forth in claim 23, wherein speed is calculated by measuring the angular rotational speed of the shaft for less than one complete revolution by sensing change of the pulse and determining the angle which the shaft rotates for the pulse to change.

25. The method as set forth in claim 1, wherein the two specific output shaft angles are specific as an angle immediately before top dead center and another angle in the range of 10°

to 20°

after top dead center.

26. The method as set forth in claim 25, wherein the specific output shaft angles are varied depending upon speed of the engine.

27. The method as set forth in claim 26, wherein the engine is a spark ignited engine and spark timing is also varied with engine speed.

28. The method as set forth in claim 26, wherein speed of rotation of output shaft is measured from a sensor that provides a single pulse during one rotation of the output shaft.

29. The method as set forth in claim 28, wherein speed is calculated by measuring angular rotational speed of the output shaft for less than one complete revolution by sensing change of the pulse and determining the angle which the output shaft rotates for the pulse to change.

44. The apparatus as set forth in claim 15, wherein the computed angle is computed by determining speed of rotation of the output shaft.

45. The apparatus as set forth in claim 44, wherein the speed sensor provides a single pulse during one rotation of the output shaft.

46. The apparatus as set forth in claim 45, wherein speed is calculated by measuring angular rotational speed of the output shaft for less than one complete revolution by sensing change of the pulse and determining the angle which the output shaft rotates for the pulse to change.

30. An apparatus for measuring torque of an internal combustion engine comprising a combustion chamber, an output shaft driven by combustion in the combustion chamber, means for measuring an instantaneous pressure condition directly in said combustion chamber, means for sensing output shaft angle, and means for reading the instantaneous pressure condition in said combustion chamber from said pressure sensor only between two specific output shaft angles occurring during only a portion of a complete cycle of operation and for less than a complete cycle and computing engine output torque for the complete cycle from said instantaneous pressure condition measurements.

31. The apparatus as set forth in claim 30, wherein change in pressure in the combustion chamber is measured.

32. The apparatus as set forth in claim 31, wherein torque is computed by an integrator that integrates change in pressure during the time period between the two specific output shaft angles.

33. The apparatus as set forth in claim 32, wherein one of the output shaft angles is the angle when the change in pressure is greatest.

34. The apparatus as set forth in claim 33, wherein the other output shaft angle is the output shaft angle where maximum pressure exists and rate of change of pressure is zero.

35. The apparatus as set forth in claim 34, wherein one of the output shaft angles is computed from known data.

36. The apparatus as set forth in claim 35, wherein the first occurring output shaft angle is the computed one.

37. The apparatus as set forth in claim 36, wherein the computed angle is computed by determining speed of rotation of the output shaft by a speed sensor.

38. The apparatus as set forth in claim 37, wherein the speed sensor provides a single pulse during one rotation of the output shaft.

39. The apparatus as set forth in claim 38, wherein the speed is calculated by measuring angular rotational speed of the shaft for less than one complete revolution by sensing change of the pulse and determining the angle which the shaft rotates for the pulse to change.

40. The apparatus as set forth in claim 30, wherein one of the output shaft angles is the angle when change in pressure is the greatest.

41. The apparatus as set forth in claim 40, wherein the other output shaft angle is output shaft angle where maximum pressure exists and rate of change of pressure is zero.

42. The apparatus as set forth in claim 41, wherein one of the output shaft angles is computed from known data.

43. The apparatus as set forth in claim 42, wherein the first occurring output shaft angle is the computed one.

47. The apparatus as set forth in claim 30, wherein the actual pressure in the combustion chamber is measured.

48. The apparatus as set forth in claim 47, wherein torque is determined by measuring difference in pressure in the combustion chamber at the two specific output shaft angles.

49. The apparatus as set forth in claim 48, wherein the two specific output shaft angles are selected as an angle immediately before top dead center and another angle in the range of 10°

to 20°

after top dead center.

50. The apparatus as set forth in claim 49, wherein the specific output shaft angles are varied depending upon speed of the engine.

51. The apparatus as set forth in claim 50, wherein the engine is a spark ignited engine and spark timing is also varied with engine speed.

52. The apparatus as set forth in claim 30, wherein the output shaft angle sensor provides a single pulse during one rotation of the shaft.

53. The apparatus as set forth in claim 52, wherein speed is calculated by measuring angular rotational speed of the output shaft for less than one complete revolution by sensing change of the pulse and determining the angle which the shaft rotates for the pulse to change.

54. The apparatus as set forth in claim 30, wherein the two specific output shaft angles are selected as an angle immediately before top dead center and another angle in the range of 10°

to 20°

after top dead center.

55. The apparatus as set forth in claim 54, wherein the specific output shaft angles are varied depending upon speed of the engine.

56. The apparatus as set forth in claim 55, wherein the engine is a spark ignited engine and spark timing is also varied with engine speed.

57. The apparatus as set forth in claim 55, wherein speed of rotation of the output shaft is measured by a sensor that provides a single pulse during one rotation of the output shaft.

58. The apparatus as set forth in claim 57, wherein speed is calculated by measuring angular rotational speed of the output shaft for less than one complete revolution by sensing change of the pulse and determining the angle which the shaft rotates for the pulse to change.