METHOD AND APPARATUS TO MONITOR QUALITY OF OPERATION OF A PISTON IN A CYLINDER

• US 3,783,681 A
• Filed: 01/16/1973
• Issued: 01/08/1974
• Est. Priority Date: 01/22/1972
• Status: Expired due to Term

• Current Assignee: Dieter Hirt, Eugen Heinle, Leonhard Gerlich
• Original Assignee: Dieter Hirt, Eugen Heinle, Leonhard Gerlich
• Inventors: Hirt, Dieter, Gerlich, Leonhard, Heinle, Eugen
• Primary Examiner(s): Myracle, Jerry W.
• Application Number:
  US05/324,111
• Time in Patent Office: 357 Days
• Field of Search: 73/116,118,119R,67.2
• US Class Current: 73/114.02
• CPC Class Codes: F02D 17/04 rendering engines inoperative or idling, e.g. caused by abnormal conditions dependent on lubricating conditions F01M1/22; dependent on cooling F01P5/14

Abstract

A transducer is connected to the cylinder sleeve or liner, and deflection, preferably axial vibration or oscillation of the liner is converted into an electrical signal, which is integrated, and detected with respect to a reference level; if a vibration frequency, particularly in the ultrasonic range is detected, or if vibration amplitudes exceed a certain level, an alarm signal is provided. The reference level may be a dynamic level, in which output signals from all cylinders of a multicylinder engine are combined, and the combined signal is utilized as a dynamic reference for comparison with any individual cylinder signal. Additional operating parameters can be considered in a logic circuit, for example fuel supply, or extent of loading on the engine, with feedback to reduce fuel supply, or shut off the engine upon detection of excessive vibration in any one or more cylinders.

Claims

1. Method of monitoring quality of operation, for example running smoothness, of a piston (P) in a cylinder (C), the cylinder having a cylinder sleeve (1) in which an output signal representative of piston operation is obtained, comprising the steps of sensing the deflection of the cylinder sleeve (1) with respect to the cylinder (C) as the piston (P) operates within the cylinder sleeve (1);

and deriving said output signal as a representation of said sensed deflection.

2. Method according to claim 1 including the step of analyzing the output signal for amplitude and generating an indication signal representative of amplitudes exceeding a predetermined level.

3. Method according to claim 1 including the step of analyzing the output signal for a predetermined frequency range, and generating an indication signal representative of frequency within said range.

4. Method according to claim 3 wherein the frequency range is in the ultrasonic range.

5. Method according to claim 1 including the step of analyzing the output signal for amplitude in excess of a certain range, and for frequency within a predetermined band and generating an indication signal representative of either amplitude in excess of a predetermined level or frequency within a predetermined range, or both.

6. Method according to claim 1 wherein the step of sensing deflection of the cylinder sleeve (1) comprises the step of sensing deflection of the cylinder sleeve in axial direction.

7. Method according to claim 1 wherein the output signal is electrical.

8. Method according to claim 1 further comprising the step of analyzing the output signal with respect to predetermined frequencies, and amplifying said predetermined frequencies.

9. Method according to claim 1 in which the output signal has negative and positive components;

and said method comprises the step of rectifying said components and integrating the rectified components.

10. Method according to claim 9 wherein the integrating time constant is essentially the same as the time of one revolution of the engine piston crankshaft.

11. Method according to claim 10 including the step of a. storing the integrated signal during one integration cycle until the end of a subsequent operation cycle of the piston, and storing the representation of the integrated signal;

b. erasing the integrated result;

c. and repeating steps (a) and (b).

12. Method to monitor a multi-cylinder engine comprising the steps of individually monitoring the respective cylinders of the engine in accordance with the method of claim 1;

and analyzing the output signals derived from the individual cylinders.

13. Method according to claim 12 including the steps of forming an average value of derived output signals from all the cylinders to provide a dynamic reference value signal;

and determining deviation of any individual output signal from said dynamic reference with respect to a predetermined level.

14. Method according to claim 13 further comprising the step of adding a signal representative approximately of signal noise level arising during the sensing and deriving steps, in any one cylinder, to said dynamic reference level to form said predetermined level.

15. Method according to claim 13 further comprising the step of indicating decrease of the dynamic reference level below a predetermined level.

16. Method according to claim 15 wherein the step of indicating drop of the dynamic reference level comprises the step of forming the difference between a signal representative of a predetermined level from the dynamic reference level signal;

and providing an indication if the remaining difference signal drops below a further predetermined level.

17. Method according to claim 12 further comprising the step of generating a signal representative of loading on the engine;

logically combining said loading signal with the individual derived output signals from the cylinder; and

controlling fuel supply to the engine in accordance with a characteristic of the logically combined loading signal and cylinder output signals.

18. Apparatus to monitor the quality of operation of a piston (P) in a cylinder (C), having a cylinder sleeve (1) to obtain an output signal representative of quality of piston operation, comprising a transducer element (3) located in vibration transfer relation to the cylinder sleeve (1) or liner;

means deriving from said transducer an electrical output signal having a characteristic representative of vibration of the cylinder sleeve, or liner; and

means (4, 5, 6, 9, 12,

     13) analyzing said signal with reference to a predetermined level (12) and deriving an alarm output (14) if the signal exceeds said predetermined level.

19. Apparatus according to claim 18 wherein the transducer element (3;

103) is hermetically sealed in the cylinder sleeve (1).

20. Apparatus to monitor the operation of a multi-cylinder engine comprising a plurality of apparatus according to claim 18, one for each cylinder;

means (15) combining the output signals from the transducers to provide a combined output signal forming a dynamic reference signal; and

means (17) comparing the combined dynamic reference signal with the signals derived from the indidual transducers of the individual cylinders to provide an alarm output if the signal from any one individual cylinder deviates from the dynamic reference signal by a predetermined amount.

21. Apparatus according to claim 20 comprising means (24'"'"''"'"') generating an engine operation signal representative of an engine operating parameter;

logic means (23) logically combining said dynamic reference signal, said individual output signals from the individual cylinders, and said operation signal, and deriving a control output signal; and

feedback circuit means (23'"'"''"'"',

     25) controlling engine operation under command of said control output signal.