EP0055563A1 - Improvements in or relating to methods of and apparatuses for determining opening of injectors - Google Patents

Improvements in or relating to methods of and apparatuses for determining opening of injectors Download PDF

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Publication number
EP0055563A1
EP0055563A1 EP81305960A EP81305960A EP0055563A1 EP 0055563 A1 EP0055563 A1 EP 0055563A1 EP 81305960 A EP81305960 A EP 81305960A EP 81305960 A EP81305960 A EP 81305960A EP 0055563 A1 EP0055563 A1 EP 0055563A1
Authority
EP
European Patent Office
Prior art keywords
injector
transducer
contact
opening
frequencies
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP81305960A
Other languages
German (de)
French (fr)
Inventor
Keith Norman Hitchcock
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Froude Consine Ltd
Original Assignee
Froude Consine Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Froude Consine Ltd filed Critical Froude Consine Ltd
Publication of EP0055563A1 publication Critical patent/EP0055563A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M65/00—Testing fuel-injection apparatus, e.g. testing injection timing ; Cleaning of fuel-injection apparatus
    • F02M65/005—Measuring or detecting injection-valve lift, e.g. to determine injection timing
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M65/00—Testing fuel-injection apparatus, e.g. testing injection timing ; Cleaning of fuel-injection apparatus
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B1/00—Engines characterised by fuel-air mixture compression
    • F02B1/02—Engines characterised by fuel-air mixture compression with positive ignition
    • F02B1/04—Engines characterised by fuel-air mixture compression with positive ignition with fuel-air mixture admission into cylinder
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B3/00—Engines characterised by air compression and subsequent fuel addition
    • F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition

Definitions

  • the present invention relates to methods of and apparatuses for determining opening of injectors. Such methods and apparatuses may be used for determining when an injector of a compression ignition engine opens. By compairing this opening time with the position of the engine crankshaft, it is possible to check the timing of the engine without having to dismantle the engine to inspect the drive to the injector arrangement.
  • a method of determining opening of an injector comprising applying an electro-acoustic transducer to the injector and monitoring the level of the output signal of the transducer to detect an increase therein indicative of opening of the injector.
  • an apparatus for determining opening of an injector comprising an electro-acoustic transducer arranged to be applied to the injector and a monitoring circuit arranged to monitor the level of the output signal of the transducer to detect an increase therein indicative of opening of the injector.
  • the transducer may comprise a contact transducer arranged to be in contact with the injector.
  • the contact transducer may be a contact microphone, for instance of the piezo-electric type which is sufficiently rugged and reliable for this type of use.
  • the transducer may be a directional microphone not actually in contact with the injector.
  • the sudden flow of fuel through the injector when it opens to inject fuel into a cylinder of the engine produces acoustic waves which propagate in the metal body of the injector.
  • the transducer receives these waves and converts them into an electrical signal whose level, at least at some frequencies, increases when the injector opens.
  • the time or rise of the amplitude of this signal corresponds to the time when the injector opens.
  • the monitoring circuit monitors the output signal of the transducer, in particular the level thereof, and provides a signal indicative of the increase in amplitude corresponding to the opening of the injector.
  • the monitoring circuit may include a filter allowing signals of frequencies corresponding to the sound produced by the injector when open to be preferentially amplified, thus increasing the signal-to-noise ratio or sensitivity of the monitoring circuit. Even when the engine is running normally and is thus producing a substantial amount of background noise, the monitoring circuit is still able to distinguish the acoustic waves produced by opening of the injector so as to produce a signal indicative of this opening.
  • the output signal from the transducer may be filtered so as to exclude noise or acoustic waves generated in other parts of the engine, thus permitting acoustic waves whose frequency is associated with the opening of the injector to be preferentially amplified.
  • the acoustic waves associated with the opening of an injector have relatively high frequency. It is possible to use frequencies up to and in the region of 400 KHz. The use of frequencies in the region of 40 KHz has been found to be particularly advantageous. Accordingly, it is preferable for the output of the transducer to be filtered so as to pass signals having frequencies in such regions while suppressing or substantially reducing output signals whose frequencies lie outside these regions.
  • a band-pass filter preferably having a centre frequency of approximately 40 KHz, may be connected to the output of the transducer.
  • the transducer is attached to the injector by-means of a spring clip. This has been found in practice to provide an adequate attachment of the transducer to the injector, and provides a quick, simple, cheap and convenient means of attachment, allowing the transducer to be readily detached when desired.
  • the method and apparatus may be used in conjunction with means for determining the position of a piston or crankshaft of an internal combustion engine so that the timing of the engine can be checked.
  • the top dead centre position can be determined by a method and apparatus as disclosed in our copending application No. (reference 230P41477X) entitled "Improvements in or relating to methods of and apparatuses for indicating a predetermind position of a piston or crankshaft of a piston engine", so that the engine timing can be checked without requiring any dismantling of the engine.
  • the engine timing can thus be checked in a very quick and convenient manner.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Testing Of Engines (AREA)

Abstract

In order to determine the opening of a fuel injector of, for instance, a compression ignition engine, an electro-acoustic transducer such as a contact microphone monitors the acoustic waves produced by the injector. A monitoring circuit detects when the level of the output signals of the transducer increases, this increase being indicative of opening of the injector. By comparing the opening time of the injector with the position of the crankshaft, the timing of the engine can be checked without requiring dismantling.

Description

  • The present invention relates to methods of and apparatuses for determining opening of injectors. Such methods and apparatuses may be used for determining when an injector of a compression ignition engine opens. By compairing this opening time with the position of the engine crankshaft, it is possible to check the timing of the engine without having to dismantle the engine to inspect the drive to the injector arrangement.
  • According to one aspect of the invention, there is provided a method of determining opening of an injector, comprising applying an electro-acoustic transducer to the injector and monitoring the level of the output signal of the transducer to detect an increase therein indicative of opening of the injector.
  • According to another aspect of the invention, there is provided an apparatus for determining opening of an injector, comprising an electro-acoustic transducer arranged to be applied to the injector and a monitoring circuit arranged to monitor the level of the output signal of the transducer to detect an increase therein indicative of opening of the injector.
  • The transducer may comprise a contact transducer arranged to be in contact with the injector. The contact transducer may be a contact microphone, for instance of the piezo-electric type which is sufficiently rugged and reliable for this type of use. Alternatively the transducer may be a directional microphone not actually in contact with the injector.
  • In the case of a fuel injector of a compression ignition or diesel engine, the sudden flow of fuel through the injector when it opens to inject fuel into a cylinder of the engine produces acoustic waves which propagate in the metal body of the injector. The transducer receives these waves and converts them into an electrical signal whose level, at least at some frequencies, increases when the injector opens. Thus, the time or rise of the amplitude of this signal corresponds to the time when the injector opens.
  • The monitoring circuit monitors the output signal of the transducer, in particular the level thereof, and provides a signal indicative of the increase in amplitude corresponding to the opening of the injector. The monitoring circuit may include a filter allowing signals of frequencies corresponding to the sound produced by the injector when open to be preferentially amplified, thus increasing the signal-to-noise ratio or sensitivity of the monitoring circuit. Even when the engine is running normally and is thus producing a substantial amount of background noise, the monitoring circuit is still able to distinguish the acoustic waves produced by opening of the injector so as to produce a signal indicative of this opening. Thus the output signal from the transducer may be filtered so as to exclude noise or acoustic waves generated in other parts of the engine, thus permitting acoustic waves whose frequency is associated with the opening of the injector to be preferentially amplified.
  • It has been found that the acoustic waves associated with the opening of an injector have relatively high frequency. It is possible to use frequencies up to and in the region of 400 KHz. The use of frequencies in the region of 40 KHz has been found to be particularly advantageous. Accordingly, it is preferable for the output of the transducer to be filtered so as to pass signals having frequencies in such regions while suppressing or substantially reducing output signals whose frequencies lie outside these regions. Thus, a band-pass filter, preferably having a centre frequency of approximately 40 KHz, may be connected to the output of the transducer.
  • This permits more accurate detection of the opening of the injector in-the presence of noise which is generated when the engine is being tested. In general, such noise has frequency components which lie outside these regions and thus may be removed or reduced sufficiently to allow a clear determination of opening of the injector to be made. Even when the noise has components, for instance, in the region of 40 KHz, . it is still possible, for instance by arranging the transducer so as to be specifically sensitive to the acoustic waves produced by the injector while being much less sensitive to noise from other sources, to provide a signal with a sufficiently good signal-to-noise ratio to allow the opening of the injector to be reliably and accurately determined.
  • In a particularly simple embodiment of the invention, the transducer is attached to the injector by-means of a spring clip. This has been found in practice to provide an adequate attachment of the transducer to the injector, and provides a quick, simple, cheap and convenient means of attachment, allowing the transducer to be readily detached when desired.
  • The method and apparatus may be used in conjunction with means for determining the position of a piston or crankshaft of an internal combustion engine so that the timing of the engine can be checked. In cases where there is no mark on a flywheel of the engine indicating top dead centre of one of the pistons, the top dead centre position can be determined by a method and apparatus as disclosed in our copending application No. (reference 230P41477X) entitled "Improvements in or relating to methods of and apparatuses for indicating a predetermind position of a piston or crankshaft of a piston engine", so that the engine timing can be checked without requiring any dismantling of the engine. The engine timing can thus be checked in a very quick and convenient manner.

Claims (19)

1. A method of determining opening of an injector, comprising applying an electro-acoustic transducer to the injector and monitoring the level of the output signal of the transducer to detect an increase therein indicative of opening of the injector.
2. A method as claimed in claim 1, in which a contact transducer is placed in contact with the injector.
3. A method as claimed in claim 2, in which the contact transducer is a contact microphone.
4. A method as claimed in claim 3, in which the contact microphone is of piezo-electric type.
5. A method as claimed in claim 1, in which the transducer is a directional microphone which is directed at the injector.
6. A method as claimed in any one of the preceding claims, in which the components of the output signal of the transducer having frequencies corresponding to the acoustic waves produced by the injector when open are monitored and components having other frequencies are substantially ignored.
7. A method as claimed in claim 6, in which components having frequencies up to substantially 400 KHz are monitored.
8. A method as claimed in claim 7, in which components having frequencies in the retion of 40 KHz are monitored.
9. A method of determining opening of an injector substantially as hereinbefore described.
10. An apparatus for determining opening of an injector, comprising an electro-acoustic transducer arranged to be applied to the injector and a monitoring circuit arranged to monitor the level of the output signal of the transducer to detect an increase therein indicative of opening of the injector.
11. An apparatus as claimed in claim 9, in which the electro-acoustic transducer is a contact transducer.
12. An apparatus as claimed in claim 10, in which the contact transducer is a contact microphone.
13. An apparatus as claimed in claim 12, in which the contact microphone is of piezo-electric type.
14. An apparatus as claimed in any one of claims 11 to 13, in which the contact transducer is provided with a spring clip for attachment to the injector.
15. An apparatus as claimed in claim 10, in which the electro-acoustic transducer is a directional microphone.
16. An apparatus as claimed in any one of claims 1 o to 15, in which the monitoring circuit includes a filter arranged to pass components of the output signal of the transducer having frequencies corresponding to the acoustic waves produced by the injector when open.
17. An apparatus as claimed in claim 16, in which the filter is arranged to pass components having frequencies up to substantially 400 KHz.
18. An apparatus as claimed in claim 17, in which the filter is a bandpass filter having a centre frequency of substantially 40 KHz.
19. An apparatus for determining opening of an injector substantially as hereinbefore described.
EP81305960A 1980-12-22 1981-12-18 Improvements in or relating to methods of and apparatuses for determining opening of injectors Withdrawn EP0055563A1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
GB8040969 1980-12-22
GB8040969 1980-12-22
GB8130970 1981-10-14
GB8130970 1981-10-14

Publications (1)

Publication Number Publication Date
EP0055563A1 true EP0055563A1 (en) 1982-07-07

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP81305960A Withdrawn EP0055563A1 (en) 1980-12-22 1981-12-18 Improvements in or relating to methods of and apparatuses for determining opening of injectors

Country Status (1)

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EP (1) EP0055563A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2512550A1 (en) * 1981-09-04 1983-03-11 Shelomentsev Timofei METHOD FOR CONTROLLING THE OPERATION OF THE MECHANISMS OF AN INTERNAL COMBUSTION ENGINE AND DEVICE FOR CARRYING OUT SAID METHOD
DE3402804A1 (en) * 1983-12-22 1985-07-11 Robert Bosch Gmbh, 7000 Stuttgart INJECTION PUMP TEST

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3580092A (en) * 1969-12-23 1971-05-25 Scarpa Lab Inc Acoustic flowmeter
DE2537219A1 (en) * 1975-08-21 1977-03-03 Daimler Benz Ag PROCEDURE FOR CHECKING THE CORRECT ANGULAR ADJUSTMENT OF PERIODIC INJECTION PROCEDURES
DE2658253A1 (en) * 1975-12-23 1977-07-07 Autoipari Kutato Intezet PROCEDURE FOR DETERMINING THE OPENING TIME OF FUEL INJECTION NOZZLES, ESPECIALLY FOR PISTON INTERNAL COMBUSTION ENGINES
DE2639133A1 (en) * 1976-08-31 1978-03-09 Siegfried Brueckl External monitoring of diesel engine injection function - using piezoelectric transducer on injection line triggering stroboscope or oscilloscope

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3580092A (en) * 1969-12-23 1971-05-25 Scarpa Lab Inc Acoustic flowmeter
DE2537219A1 (en) * 1975-08-21 1977-03-03 Daimler Benz Ag PROCEDURE FOR CHECKING THE CORRECT ANGULAR ADJUSTMENT OF PERIODIC INJECTION PROCEDURES
US4109517A (en) * 1975-08-21 1978-08-29 Daimler-Benz Aktiengesellschaft Method and apparatus for controlling the correct angular adjustment of periodic injection operations
DE2658253A1 (en) * 1975-12-23 1977-07-07 Autoipari Kutato Intezet PROCEDURE FOR DETERMINING THE OPENING TIME OF FUEL INJECTION NOZZLES, ESPECIALLY FOR PISTON INTERNAL COMBUSTION ENGINES
US4102181A (en) * 1975-12-23 1978-07-25 Autoipari Kutato Intezet Procedure for determining the starting point of fuel injection especially for running internal-combustion engines
GB1555018A (en) * 1975-12-23 1979-11-07 Autoipari Kutato Intezet Determining the starting point for fuel injection in internal-combustion engines
DE2639133A1 (en) * 1976-08-31 1978-03-09 Siegfried Brueckl External monitoring of diesel engine injection function - using piezoelectric transducer on injection line triggering stroboscope or oscilloscope

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2512550A1 (en) * 1981-09-04 1983-03-11 Shelomentsev Timofei METHOD FOR CONTROLLING THE OPERATION OF THE MECHANISMS OF AN INTERNAL COMBUSTION ENGINE AND DEVICE FOR CARRYING OUT SAID METHOD
DE3402804A1 (en) * 1983-12-22 1985-07-11 Robert Bosch Gmbh, 7000 Stuttgart INJECTION PUMP TEST

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PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

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AK Designated contracting states

Designated state(s): AT DE FR IT NL SE

17P Request for examination filed

Effective date: 19820820

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: FROUDE CONSINE LIMITED

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19840103

RIN1 Information on inventor provided before grant (corrected)

Inventor name: HITCHCOCK, KEITH NORMAN