WO1995006812A1 - Synchronizing system for internal combustion engines - Google Patents
Synchronizing system for internal combustion engines Download PDFInfo
- Publication number
- WO1995006812A1 WO1995006812A1 PCT/EP1994/002920 EP9402920W WO9506812A1 WO 1995006812 A1 WO1995006812 A1 WO 1995006812A1 EP 9402920 W EP9402920 W EP 9402920W WO 9506812 A1 WO9506812 A1 WO 9506812A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- pulse
- tooth
- wheel
- engine
- pulse wheel
- Prior art date
Links
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
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/04—Introducing corrections for particular operating conditions
- F02D41/06—Introducing corrections for particular operating conditions for engine starting or warming up
- F02D41/062—Introducing corrections for particular operating conditions for engine starting or warming up for starting
-
- 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
- F02B2275/00—Other engines, components or details, not provided for in other groups of this subclass
- F02B2275/14—Direct injection into combustion chamber
-
- 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
- F02D2041/0092—Synchronisation of the cylinders at engine start
Definitions
- the present invention relates to a synchronizing system for internal combustion engines, which may be applied in particular to the high-pressure- electronic injection system of high-speed, direct-injection diesel engines.
- electronic injection systems comprise a control system which, to regulate the controlled variables involved, must be synchronized with the engine for it to know the exact engine stroke and angular position of the crankshaft at all times.
- crankshaft When the engine is turned off (ignition key in the off position) , the crankshaft continues turning by force of inertia, so that, when the engine is turned on,, the angular position of the crankshaft is unknown and the engine must be synchronized.
- the pulse wheel fitted to the drive shaft presents a number of teeth equally spaced about the periphery of the wheel with the exception of an untoothed portion corresponding to a gap of two teeth and which represents a reference or zero by which to count the teeth on the wheel.
- the pulse wheel fitted to the camshaft generally comprises only two teeth separated by an angular distance of, say, 90°.
- the amplitude of the pulse wheel signals at low startup engine speed is so low as to be unusable for identifying the teeth, thus requiring a further delay of roughly half a turn of the shaft for the engine to be synchronized.
- a synchronizing system for an internal combustion engine comprising a first pulse wheel fitted to the drive shaft and presenting a number of equally spaced teeth with the exception of at least one untoothed portion; a second pulse wheel fitted to the camshaft and comprising at least one tooth; -and a first and second transducer for said first and second pulse wheels respectively, for generating a respective electric signal presenting a pulse corresponding to detection of each tooth on the relative pulse wheel; characterized in that said first and second pulse wheels are positioned in a predetermined manner in relation to each other.
- Figure 1 shows the pulse wheels of the synchronizing system according to the present invention
- Figure 2 shows the electric signals corresponding to the Figure 1 pulse wheel readings.
- Figure 1 shows the two pulse wheels of the system according to the present invention.
- Number 1 indicates the pulse wheel (also referred to as the drive pulse wheel) fitted to the drive shaft 2 of a high-speed, direct-injection diesel engine (not shown) , and which, in the example shown, comprises 58 teeth 3 (one every 6°) , and an untoothed portion 4 corresponding to a gap of two teeth and constituting a start reference for the tooth count.
- An inductive type sensor or pickup 5 is positioned facing drive wheel 1, for detecting the tooth sequence of wheel 1 and generating an electric signal which is filtered and clipped to give signal- S M ( Figure 2) characterized by a sequence of pulses (corresponding to teeth 3) interrupted solely (signal portion 6) at untoothed portion 4.
- Number 9 indicates the pulse wheel (also referred to as the cam pulse wheel) fitted to the camshaft 8, and which presents, in known manner, only two teeth 10, 11 separated, for example, by an angular distance of 90° in rotation direction A.
- Cam wheel 9 presents a sensor 12 similar to sensor 5, for generating a signal which is processed as for signal S.. to give signal S ( Figure 2) presenting only two pulses 13, 14 corresponding to teeth 10, 11.
- the engine (not shown) presents a 1-3-4-2 timing sequence, and the top dead center position at the end of the compression stroke of each cylinder corresponds to the positioning of teeth N. 23 and 53 of drive wheel 1 opposite sensor 5. Since, as already stated, each engine cycle corresponds to two turns of the drive shaft, it follows that, when tooth N.
- cam wheel 9 is arranged in a precise angular position with respect to drive wheel 1. More specifically, pulse wheels 1 and 9 are so fitted that tooth 10, which precedes tooth 11 by 90° in rotation direction A of cam wheel 9, is detected by sensor 12 when one of the first ten teeth of drive wheel 1 moves past sensor 5, as shown in Figure 2.
- the synchronizing procedure provides that the processing system receiving signals S M and S correlated to the signals of sensors 5 and 12 be switched to standby awaiting portion 6 of " signal S M ; and, upon detection of portion 6 (passage of untoothed portion 4 past sensor 5) , the system switches to standby awaiting pulse 13 corresponding to the passage of tooth 10 of cam wheel 9.
- the synchronizing system described therefore provides for rapidly detecting the engine stroke and hence rapidly synchronizing the engine, as well as for minimizing startup time and attainment of the steady-state condition of the engine.
- the cam wheel may present one tooth instead of two, seeing as the second tooth, though offering a greater margin of safety in some situations, is not necessarily required by the synchronizing procedure described; and, though described with reference to a four-cylinder engine, the system according to the present invention may also be applied equally as well to five- or six-cylinder engines.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Valve Device For Special Equipments (AREA)
- Diaphragms For Electromechanical Transducers (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
- Transmission And Conversion Of Sensor Element Output (AREA)
Abstract
A synchronizing system for an internal combustion engine, including a first pulse wheel (1) fitted to the drive shaft (2) and presenting a number of equally spaced teeth (3) with the exception of at least one untoothed portion (4); a second pulse wheel (9) fitted to the camshaft (8) and presenting at least one tooth (10); and a respective first and second transducer (5, 12) for the two pulse wheels. The outputs of the transducers are processed to give two electric signals (SM, SC), each presenting a pulse corresponding to the detection of each tooth on the relative pulse wheel. To speed up identification of the engine stroke when the engine is started up, the two pulse wheels (1, 9) are positioned in a predetermined manner in relation to each other.
Description
SYNCHRONIZING SYSTEM FOR INTERNAL COMBUSTION ENGINES
TECHNICAL FIELD The present invention relates to a synchronizing system for internal combustion engines, which may be applied in particular to the high-pressure- electronic injection system of high-speed, direct-injection diesel engines. BACKGROUND ART
As is known, electronic injection systems comprise a control system which, to regulate the controlled variables involved, must be synchronized with the engine for it to know the exact engine stroke and angular position of the crankshaft at all times.
When the engine is turned off (ignition key in the off position) , the crankshaft continues turning by force of inertia, so that, when the engine is turned on,, the angular position of the crankshaft is unknown and the engine must be synchronized.
This is done using two pulse wheels fitted respectively to the drive shaft and camshaft and each cooperating with a respective sensor for detecting the
tooth sequence on the respective wheel and generating a corresponding electric signal. The pulse wheel fitted to the drive shaft presents a number of teeth equally spaced about the periphery of the wheel with the exception of an untoothed portion corresponding to a gap of two teeth and which represents a reference or zero by which to count the teeth on the wheel. Conversely, the pulse wheel fitted to the camshaft generally comprises only two teeth separated by an angular distance of, say, 90°.
As each engine cycle corresponds to two turns of the drive shaft, the angular position of the-drive shaft alone is not enough for determining the engine stroke, so that the signals of both pulse wheels are needed for synchronizing the engine. At present therefore, when the engine is started up, the signals generated by both pulse wheels are detected for at least two complete turns of the drive shaft to determine the presence of the pulses generated by the teeth on the camshaft wheel. Such a solution therefore involves a certain amount of delay due, as stated, to the drive shaft necessarily effecting at least two complete turns.
Moreover, being related to engine speed, the amplitude of the pulse wheel signals at low startup engine speed is so low as to be unusable for identifying the teeth, thus requiring a further delay of roughly half a turn of the shaft for the engine to be synchronized.
DISCLOSURE OF INVENTION
It is an object of the present invention to provide a synchronizing system permitting faster identification of the engine stroke when the engine is started up.
According to the present invention, there is provided a synchronizing system for an internal combustion engine, comprising a first pulse wheel fitted to the drive shaft and presenting a number of equally spaced teeth with the exception of at least one untoothed portion; a second pulse wheel fitted to the camshaft and comprising at least one tooth; -and a first and second transducer for said first and second pulse wheels respectively, for generating a respective electric signal presenting a pulse corresponding to detection of each tooth on the relative pulse wheel; characterized in that said first and second pulse wheels are positioned in a predetermined manner in relation to each other. BRIEF DESCRIPTION OF DRAWINGS
A preferred, non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:
Figure 1 shows the pulse wheels of the synchronizing system according to the present invention;
Figure 2 shows the electric signals corresponding to the Figure 1 pulse wheel readings.
BEST MODE FOR CARRYING OUT THE INVENTION
Figure 1 shows the two pulse wheels of the system according to the present invention. Number 1 indicates the pulse wheel (also referred to as the drive pulse wheel) fitted to the drive shaft 2 of a high-speed, direct-injection diesel engine (not shown) , and which, in the example shown, comprises 58 teeth 3 (one every 6°) , and an untoothed portion 4 corresponding to a gap of two teeth and constituting a start reference for the tooth count. An inductive type sensor or pickup 5 is positioned facing drive wheel 1, for detecting the tooth sequence of wheel 1 and generating an electric signal which is filtered and clipped to give signal- SM (Figure 2) characterized by a sequence of pulses (corresponding to teeth 3) interrupted solely (signal portion 6) at untoothed portion 4.
Number 9 indicates the pulse wheel (also referred to as the cam pulse wheel) fitted to the camshaft 8, and which presents, in known manner, only two teeth 10, 11 separated, for example, by an angular distance of 90° in rotation direction A. Cam wheel 9 presents a sensor 12 similar to sensor 5, for generating a signal which is processed as for signal S.. to give signal S (Figure 2) presenting only two pulses 13, 14 corresponding to teeth 10, 11. In the embodiment shown, the engine (not shown) presents a 1-3-4-2 timing sequence, and the top dead center position at the end of the compression stroke of each cylinder corresponds to the positioning of teeth
N. 23 and 53 of drive wheel 1 opposite sensor 5. Since, as already stated, each engine cycle corresponds to two turns of the drive shaft, it follows that, when tooth N. 23 is positioned opposite sensor 5, the engine alternately presents the third and second cylinder in the compression top dead center position (stroke TDC3 or TDC2) ; whereas, when tooth N. 53 is positioned opposite sensor 5, the engine alternately presents the first and fourth cylinder in the compression top dead center position (stroke TDCl or TDC4) . In practice, if in one turn the passage of tooth N. 23 past" sensor 5 corresponds to the top dead center position of the third cylinder (TDC3) , the subsequent passage of tooth N. 53 in the same turn corresponds to the top dead center position of the fourth cylinder (TDC4) ; and, in the next turn, the passage of tooth N. 23 corresponds to the top dead center position of the second cylinder (TDC2) , and the passage of tooth N. 53 corresponds to the top dead center position of the first cylinder (TDCl) , as shown in Figure 2. To determine whether the passage of tooth N. 23 corresponds to the top dead center position of the third or second cylinder when the engine is started up, use must therefore be made of the signal generated by sensor 12 of cam wheel 9 for which, having a period twice that of drive wheel 1, the position of the pulses corresponding to teeth 10, 11 is related solely to the position of the engine cylinders.
According to the present invention, to speed up
synchronization when the engine is started up, cam wheel 9 is arranged in a precise angular position with respect to drive wheel 1. More specifically, pulse wheels 1 and 9 are so fitted that tooth 10, which precedes tooth 11 by 90° in rotation direction A of cam wheel 9, is detected by sensor 12 when one of the first ten teeth of drive wheel 1 moves past sensor 5, as shown in Figure 2. Upon startup, the synchronizing procedure provides that the processing system receiving signals SM and S correlated to the signals of sensors 5 and 12 be switched to standby awaiting portion 6 of "signal SM; and, upon detection of portion 6 (passage of untoothed portion 4 past sensor 5) , the system switches to standby awaiting pulse 13 corresponding to the passage of tooth 10 of cam wheel 9. If pulse 13 is detected within a time lapse corresponding to ten pulses of signal S„, this means the next top dead center position (passage of tooth N. 23) corresponds to TDC3; conversely, the next passage of tooth N. 23 corresponds to TDC2. The system thus provides for exactly determining the stroke of the engine (and so activating the right injection sequence) with a delay corresponding at most to a rotation of 420° (one full turn plus angle α corresponding to the first ten teeth of drive wheel 1) . Figures 1 and 2 also show the fuel injection regions 15 which may be controlled effectively by virtue of synchronizing the engine as described above, and which are defined by the detection of teeth 16, 27 and
teeth 46, 57 respectively.
The synchronizing system described therefore provides for rapidly detecting the engine stroke and hence rapidly synchronizing the engine, as well as for minimizing startup time and attainment of the steady-state condition of the engine.
Moreover, the system described involves no additional expense by virtue of employing conventional pulse wheels and software procedures which may be implemented easily and cheaply on existing elements.
Clearly, changes may be made to the- system as described and illustrated herein without, however, departing from the scope of the present invention. In particular, the cam wheel may present one tooth instead of two, seeing as the second tooth, though offering a greater margin of safety in some situations, is not necessarily required by the synchronizing procedure described; and, though described with reference to a four-cylinder engine, the system according to the present invention may also be applied equally as well to five- or six-cylinder engines.
Claims
1) A synchronizing system for an internal combustion engine, comprising a first pulse wheel (1) fitted to the drive shaft (2) and presenting a number of equally spaced teeth (3) with the exception of at least one untoothed portion (4) ; a second pulse wheel (9) fitted to the camshaft (8) and comprising at least one tooth (10) ; and a first and second transducer (5, 12) for said first and second pulse wheels respectively, for generating a respective electric signal (S , Sr) presenting a pulse corresponding to detection of each tooth on the relative pulse wheel; characterized in that said at least one tooth (10) of said second pulse wheel (9) is so located as to be detected by the respective transducer (12) , at every other turn of said drive shaft (2) , alongside detection of one of the first n teeth of said first pulse wheel (l) following said untoothed portion (4) . 2) A system as claimed in Claim 1, characterized in that n equals ten.
3) A system as claimed in Claim 1 or 2, characterized in that it comprises means (5) for detecting the passage of said untoothed portion (4) of said first pulse wheel (1) ; and means (12) for detecting the passage of said at least one tooth (10) of said second pulse wheel (9) alongside the passage of said first n teeth of said first pulse wheel (1) and so
determining a first engine stroke, or for detecting the absence of said at least one tooth of said second pulse wheel alongside the passage of said first n teeth of said first pulse wheel and so determining a second engine stroke.
4) A synchronizing system for an internal combustion engine, substantially as described and illustrated herein with reference to the accompanying drawings.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
ITTO93A000647 | 1993-09-03 | ||
ITTO930647A IT1261576B (en) | 1993-09-03 | 1993-09-03 | SYNCHRONIZATION SYSTEM OF AN INTERNAL COMBUSTION ENGINE |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1995006812A1 true WO1995006812A1 (en) | 1995-03-09 |
Family
ID=11411711
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP1994/002920 WO1995006812A1 (en) | 1993-09-03 | 1994-09-02 | Synchronizing system for internal combustion engines |
Country Status (2)
Country | Link |
---|---|
IT (1) | IT1261576B (en) |
WO (1) | WO1995006812A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2312017A (en) * | 1996-04-10 | 1997-10-15 | Caterpillar Inc | Timing fuel injection in i.c. engines by sensing rotation of crankshaft and camshaft |
EP0831224A2 (en) * | 1996-09-19 | 1998-03-25 | Robert Bosch Gmbh | Sensor arrangement for rapid cylinder identification in an internal combustion engine |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2637652A1 (en) * | 1988-10-11 | 1990-04-13 | Bendix Electronics Sa | Device for marking an operating cycle of an internal combustion engine |
WO1991001443A1 (en) * | 1989-07-15 | 1991-02-07 | Robert Bosch Gmbh | Sequential fuel injection process |
DE4125675A1 (en) * | 1991-08-02 | 1993-02-04 | Audi Ag | Camshaft-referenced controller for four-stroke combustion engine - detects leading edge of pulse from camshaft and counts crankshaft pulses until reference signal is detected |
WO1993012333A1 (en) * | 1991-12-18 | 1993-06-24 | Robert Bosch Gmbh | TRANSMITTER ARRANGEMENT FOR CYLINDER RECOGNITION IN AN INTERNAL COMBUSTION ENGINE WITH n CYLINDERS |
-
1993
- 1993-09-03 IT ITTO930647A patent/IT1261576B/en active IP Right Grant
-
1994
- 1994-09-02 WO PCT/EP1994/002920 patent/WO1995006812A1/en active Application Filing
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2637652A1 (en) * | 1988-10-11 | 1990-04-13 | Bendix Electronics Sa | Device for marking an operating cycle of an internal combustion engine |
WO1991001443A1 (en) * | 1989-07-15 | 1991-02-07 | Robert Bosch Gmbh | Sequential fuel injection process |
DE4125675A1 (en) * | 1991-08-02 | 1993-02-04 | Audi Ag | Camshaft-referenced controller for four-stroke combustion engine - detects leading edge of pulse from camshaft and counts crankshaft pulses until reference signal is detected |
WO1993012333A1 (en) * | 1991-12-18 | 1993-06-24 | Robert Bosch Gmbh | TRANSMITTER ARRANGEMENT FOR CYLINDER RECOGNITION IN AN INTERNAL COMBUSTION ENGINE WITH n CYLINDERS |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2312017A (en) * | 1996-04-10 | 1997-10-15 | Caterpillar Inc | Timing fuel injection in i.c. engines by sensing rotation of crankshaft and camshaft |
US5860406A (en) * | 1996-04-10 | 1999-01-19 | Caterpillar Inc. | Engine timing apparatus and method of operating same |
EP0831224A2 (en) * | 1996-09-19 | 1998-03-25 | Robert Bosch Gmbh | Sensor arrangement for rapid cylinder identification in an internal combustion engine |
EP0831224A3 (en) * | 1996-09-19 | 1999-10-20 | Robert Bosch Gmbh | Sensor arrangement for rapid cylinder identification in an internal combustion engine |
Also Published As
Publication number | Publication date |
---|---|
ITTO930647A1 (en) | 1995-03-03 |
IT1261576B (en) | 1996-05-23 |
ITTO930647A0 (en) | 1993-09-03 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5469823A (en) | Sensor arrangement for rapid cylinder detection in a multi-cylinder internal combustion engine | |
US4766865A (en) | Device for determining the position of a crankshaft in relation to the cylinder | |
JP3734496B2 (en) | Transmitter device for cylinder identification in an internal combustion engine having n cylinders | |
JP3261212B2 (en) | Cylinder discrimination method for fuel injection device of internal combustion engine | |
US4926822A (en) | Control system for an automotive engine | |
EP2541029B1 (en) | Four-stroke cycle internal combustion engine and method of identifying cylinder of four-stroke cycle internal combustion engine | |
EP0846852B1 (en) | A method of synchronizing an internal combustion engine without a cam position sensor | |
JPS63198740A (en) | Crank angle detecting device for internal combustion engine | |
KR100624352B1 (en) | Phase recognition device | |
US5860406A (en) | Engine timing apparatus and method of operating same | |
EP0990784B1 (en) | Method for the synchronisation of an internal combustion engine | |
JPH01240751A (en) | Angle detecting device for internal combustion engine | |
JP2813210B2 (en) | Cylinder identification device for internal combustion engines | |
US6202634B1 (en) | Process for recognizing the ignition cycle of a certain cylinder during the start of an internal-combustion engine | |
US6494086B1 (en) | System for detecting the operative strokes of an internal combustion reciprocating engine | |
US20080295803A1 (en) | Camshaft wheel for determining startup engine angle and machine using same | |
US5042449A (en) | Method and related system for controlling the ignition in internal combustion engines, particularly direct-ignition engines with individual coils | |
WO1995006812A1 (en) | Synchronizing system for internal combustion engines | |
US7171925B2 (en) | Method for reversing the direction of rotation of a two-stroke engine | |
US6523523B2 (en) | Camless engine with crankshaft position feedback | |
US6058766A (en) | Crank angle detector | |
JPS62182463A (en) | Reverse revolution preventing device for internal combustion engine | |
KR0162946B1 (en) | Apparauts and method for determining engine revolution displacement for multi-cylinder four stroke internal combustion engine | |
JP3596782B2 (en) | Engine rotation signal detection device | |
EP0684377A1 (en) | Electronic system for identifying the strokes of an internal combustion engine |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): CN JP KR US |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
122 | Ep: pct application non-entry in european phase |