GB2103366A - Test apparatus for ignition timing - Google Patents
Test apparatus for ignition timing Download PDFInfo
- Publication number
- GB2103366A GB2103366A GB08217056A GB8217056A GB2103366A GB 2103366 A GB2103366 A GB 2103366A GB 08217056 A GB08217056 A GB 08217056A GB 8217056 A GB8217056 A GB 8217056A GB 2103366 A GB2103366 A GB 2103366A
- Authority
- GB
- United Kingdom
- Prior art keywords
- fuel
- engine
- injection nozzle
- signal
- output signal
- 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- Withdrawn
Links
- 238000012360 testing method Methods 0.000 title abstract description 7
- 239000000446 fuel Substances 0.000 claims abstract description 30
- 238000002347 injection Methods 0.000 claims abstract description 20
- 239000007924 injection Substances 0.000 claims abstract description 20
- 238000002485 combustion reaction Methods 0.000 claims abstract description 8
- 238000007493 shaping process Methods 0.000 claims abstract description 8
- 230000006835 compression Effects 0.000 claims abstract description 7
- 238000007906 compression Methods 0.000 claims abstract description 7
- 230000000694 effects Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 230000003466 anti-cipated effect Effects 0.000 description 1
- 238000013016 damping Methods 0.000 description 1
- 239000013536 elastomeric material Substances 0.000 description 1
- 239000004519 grease Substances 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/009—Electrical control of supply of combustible mixture or its constituents using means for generating position or synchronisation signals
-
- 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
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/14—Introducing closed-loop corrections
- F02D41/1401—Introducing closed-loop corrections characterised by the control or regulation method
- F02D2041/1413—Controller structures or design
- F02D2041/1432—Controller structures or design the system including a filter, e.g. a low pass or high pass filter
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Fuel-Injection Apparatus (AREA)
- Ignition Installations For Internal Combustion Engines (AREA)
- Testing Of Engines (AREA)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
- Measuring Pulse, Heart Rate, Blood Pressure Or Blood Flow (AREA)
- Eye Examination Apparatus (AREA)
Abstract
A test apparatus for use in the adjustment of the timing of fuel delivery to a combustion chamber of a compression ignition engine having a fuel injection nozzle with a fuel-pressure- actuated spring-loaded valve member includes a vibration sensor 11 adapted to be clamped to or held against the nozzle 10. The output signal from the sensor is passed through a band pass amplifier 12 and a band pass or high pass filter 13 to a pulse shaping circuit 14. A stroboscope 15 is controlled by the output signal of the circuit 12 and can be used to illuminate a rotary part of the engine. A sensor 20 provides engine position signals to logic unit 16 controlling a display 17 of timing information. <IMAGE>
Description
SPECIFICATION
Test apparatus
This invention relates to apparatus for use in the adjustment of the timing of the injection of fuel through an injection nozzle incorporating a fuel pressure actuated spring loaded valve, to a combustion chamber of a compression ignition engine.
The correct adjustment of the timing of fuel delivery to a compression ignition engine is becoming more and more important as fuel becomes more expensive, emission laws become more stringent and as the requirement to reduce noise increases.
Static timing that is to say where marks on the fuel pump and engine are aligned during the assembly of the pump to the engine is no longer considered sufficiently accurate although it can still be used for rough timing during assembly. In order to provide the required degree of accuracy, dynamic timing has to be employed.
It is known to apply a transducer to the fuel pipe which connects the injection nozzle with the injection pump. When fuel is supplied by the pump the pressure wave in the column of fuel causes a slight expansion of the pipe and this produces a signal in the transducer which can be related to the position of the rotary parts of the engine to provide a timing signal at the particular engine speed. In practice this method of testing is not satisfactory firstly because the arrival of the pressure wave at the point in the pipe where the transducer is attached, is not a true indication of the delivery of fuel into the combustion space seondly, the transducer needs to be carefully constructed and sited so that the effect of engine vibration is minimised and thirdly the position of the transducer on the pipe in some fuel systems has a profound effect upon the accuracy of the timing signal.
It has been proposed to construct special injection nozzles which provide a signal indicative of the lift of the valve member in the nozzle. The signal thus obtained is a true representation of the delivery of fuel to the combustion space but a special nozzle is required which is expensive and must be specially fitted for the test and removed afterwards.
The object of the invention is to provide an apparatus for the purpose specified in a simple and convenient form.
According to the invention an apparatus for the purpose specified comprise a vibration sensor adapted to be located in use, against the body of the injection nozzle so as to provide a signal at least when the valve member of the nozzle contacts its seating at the termination of delivery of fuel, filter means which receives the output of the sensor and provides an output signal in which said signal is accentuated and means responsive to said output signal.
An example of an apparatus in accordance with the invention will now be described with reference to the accompanying diagram.
In the diagram an injection nozzle is indicated at 10 this being a conventional nozzle and one of a set of nozzles fitted to a compression ignition engine the dynamic timing of the fuel injection pump of which is to be checked. The nozzle incorporates a fuel pressure operated valve member which is urged into contact with a seating to prevent flow of fuel to the associated combustion space, by means of a coiled compression spring. When fuel is supplied to the nozzle the valve member is lifted from the seating and when the supply of fuel ceases it is returned rapidly to the seating and impacts therewith.
The apparatus includes a vibration sensor in the form of an accelerometer 11 which is provided with a clamp so that it can be located against the body of the injection nozzle. The output signal of the accelerometer contains amongst others, a signal which is generated when the valve member impacts upon the seating. This signal must be isolated and accentuated, from the remaining signals which in general are signals due to engine vibration. The output signal is therefore applied to the input of a band pass amplifier 12 the output of which is passed through a band pass filter 13 to a pulse shaping circuit 14, the pass bands of the filter and amplifier being in the order of 6-16 KHz. If desired a high pass filter may be used.
In a simple version of the apparatus the output of the pulse shaping circuit 14 is applied to the control circuit of a stroboscope 15, which includes a lamp which can be directed to illuminate a rotary part of the engine whereby the instant of closure of the valve member of the injection nozzle can be related to the position of the rotary part of the engine for example the flywheel. It is possible to incorporate an adjustable delay 1 so, so that the flash produced by the stroboscope occurs at a known interval after the impact of the valve member with its seat. It is thus possible for the flash to occur at such a time that when the engine timing is correct the rotary part of the engine illuminates by the stroboscope to be at a predetermined position.
In the more sophisticated arrangement of the apparatus as illustrated, the output of the pulse shaper 14 is applied to a logic unit 16 having an output to the stroboscope 15 but also having outputs connected to a display 17. In addition, the logic unit 16 receives from a further pulse shaping circuit 18, a signal or signals indicative of the engine position.
These signals are provided by a band pass amplifier 19 the input of which is connected to a sensor 20 responsive to markings on a disc 21 which can be secured to a rotary part of the engine so as to rotate therewith. The display 17 using the signals derived from the sensor 20, displays the signal representing the closure of the valve member of the injection nozzle to provide an indication of the timing difference. The display may be calibrated such that the operator may be provided with an indication in degrees, of the difference between the actual timing and the required timing and the display may display the engine speed this being determined from the signal provided by the sensor 20 or the accelerometer 11.
It is anticipated that the test will be carried out at designated engine speeds only for which speeds manufacturer's data on the pump and fuel system have been made available. In most cases it may only be necessary to carry out the test at one engine speed.
The so-called manufacturer's data will take into account the fact that some forms of fuel pump have a constant start of delivery irrespective of the amount of fuel delivered whilst others have a constant end of delivery.
The apparatus may form part of an overall electronic control system for the pump, supplying signals to parts of the control system from which signals representative of the start of combustion af fuel in the engine cylinder can be obtained.
The tests as described above are generally carried out at low engine loads and low speeds. As a result the valve member of the nozzle will not engage its stop and onlythe impact of the valve member on its seating will be detected by the accelerometer. In the case where the apparatus forms part of an overall engine control system then as the engine speed and/orthe load increases, the valve member will contact its stop to produce a similar impact signal to that which occurs when to valve member contacts its seating. The system must therefore include means to prevent the signal produced by the impact of the valve member with its stop being processed as the valve closure signal.In this case the shaping circuit can be provided with an additional output providing for example, a rectangular pulse signal which can be used in the engine control system.
The accelerometer has been described as being clamped in use, to the injection nozzle. The clam is designed so that it incorporates considerabledamp- ing in orderto minimise-resonance effects. This may be achieved by securing a layer or layers of damping medium to the body of the clamp. In some instances it may not be possible ta clamp the accelerometer against the injection nozzle due to lack of space. It is however possible to obtain a suitable signal by holding the accelerometer in a hand held probe againstthe nozzle. In orderto improve the response of the accelerometer it is preferable to coat the surfaces of the clamp or accelerometer which engage the nozzle, with grease or an elastomeric material.
Claims (9)
1. An apparatus for use in the adjustment of the timing of injection of fuel through a fuel injection nozzle incorporating a fuel pressure actuated spring loaded valve, to a combustion chamber of a compression ignition engine, the apparatus comprising a vibration sensor adapted to be located in use, against the body of the injection nozzle so as to provide a signal at least when the valve member of the nozzle contacts its seating at the termination of delivery of fuel, filter means which receives the output of the sensor and provides an output signal in which said signal is accentuated and means respon size to said output signal.
2. An apparatus according to claim 1, in which said filter means includes a band pass amplifier and a band pass or high pass filter.
3. An apparatus according to claim 2, in which said filter means includes a pulse shaping circuit
4. An apparatus according to claim 3, in which the means responsive to the output signal is a stroboscope.
5. An apparatus according to claim 4, including an adjustable delay positioned between the shaping circuit and the stroboscope.
6. An apparatus according to claim 4, including a logic unit disposed between the pulse shaping circuit and the stroboscope, a display connected to the logic unit to receive signals therefrom, and a sensor for providing signals to the logic unit corresponding to the markings on a rotary disc adapted in use, to be secured to a rotary part of the engine.
7. An apparatus according to claim 1, in which said vibration sensor comprises an accelerometer.
8. An apparatus including a clamp for clamping the accelerometer to the injection nozzle.
9. An apparatus for use in the adjustment of the timing of injection of fuel through a fuel injection nozzle incorporating a fuel pressure actuated spring loaded valve, to a combustion chamber of a compression ignition engine comprising the combination and arrangement of parts substantially as hereinbefore described.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8119913 | 1981-06-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB2103366A true GB2103366A (en) | 1983-02-16 |
Family
ID=10522862
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08217056A Withdrawn GB2103366A (en) | 1981-06-27 | 1982-06-11 | Test apparatus for ignition timing |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS588264A (en) |
| ES (1) | ES513508A0 (en) |
| FR (1) | FR2508557A1 (en) |
| GB (1) | GB2103366A (en) |
| IT (1) | IT1237559B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2122350A (en) * | 1982-05-12 | 1984-01-11 | Avl Verbrennungskraft Messtech | Checking valve clearances on a piston engine |
| GB2122252A (en) * | 1982-06-21 | 1984-01-11 | Froude Eng Ltd | Stroboscopic engine fuel-injection timing |
| US4444049A (en) * | 1980-12-22 | 1984-04-24 | Froude Consine Limited | Engine testing apparatus and methods |
| GB2146119A (en) * | 1983-09-05 | 1985-04-11 | Froude Consine Ltd | Detection of fuel injection |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3731527A (en) * | 1970-11-27 | 1973-05-08 | Umc Electronics Co | Fuel injection transducer and timing system |
| DE2513288C2 (en) * | 1975-03-26 | 1981-12-10 | Krupp Mak Maschinenbau Gmbh, 2300 Kiel | Measuring device for an internal combustion engine for determining the angular distance between the start of fuel injection of an injection nozzle and the top dead center of the internal combustion engine cylinder assigned to the nozzle |
| DE2537219A1 (en) * | 1975-08-21 | 1977-03-03 | Daimler Benz Ag | PROCEDURE FOR CHECKING THE CORRECT ANGULAR ADJUSTMENT OF PERIODIC INJECTION PROCEDURES |
-
1982
- 1982-06-11 GB GB08217056A patent/GB2103366A/en not_active Withdrawn
- 1982-06-22 FR FR8210911A patent/FR2508557A1/en not_active Withdrawn
- 1982-06-22 IT IT8221996A patent/IT1237559B/en active
- 1982-06-26 JP JP57110563A patent/JPS588264A/en active Pending
- 1982-06-26 ES ES513508A patent/ES513508A0/en active Granted
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4444049A (en) * | 1980-12-22 | 1984-04-24 | Froude Consine Limited | Engine testing apparatus and methods |
| GB2122350A (en) * | 1982-05-12 | 1984-01-11 | Avl Verbrennungskraft Messtech | Checking valve clearances on a piston engine |
| GB2122252A (en) * | 1982-06-21 | 1984-01-11 | Froude Eng Ltd | Stroboscopic engine fuel-injection timing |
| GB2146119A (en) * | 1983-09-05 | 1985-04-11 | Froude Consine Ltd | Detection of fuel injection |
Also Published As
| Publication number | Publication date |
|---|---|
| IT8221996A0 (en) | 1982-06-22 |
| IT1237559B (en) | 1993-06-08 |
| JPS588264A (en) | 1983-01-18 |
| FR2508557A1 (en) | 1982-12-31 |
| ES8403192A1 (en) | 1983-06-16 |
| ES513508A0 (en) | 1983-06-16 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |