GB2417290A - Reducing knock in i.c. engines - Google Patents

Reducing knock in i.c. engines Download PDF

Info

Publication number
GB2417290A
GB2417290A GB0418569A GB0418569A GB2417290A GB 2417290 A GB2417290 A GB 2417290A GB 0418569 A GB0418569 A GB 0418569A GB 0418569 A GB0418569 A GB 0418569A GB 2417290 A GB2417290 A GB 2417290A
Authority
GB
United Kingdom
Prior art keywords
engine
knock
air
cylinder
valve
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.)
Granted
Application number
GB0418569A
Other versions
GB2417290B (en
GB0418569D0 (en
Inventor
E T Bishop
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.)
Connaught Motor Co Ltd
Original Assignee
Connaught Motor Co 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 Connaught Motor Co Ltd filed Critical Connaught Motor Co Ltd
Priority to GB0418569A priority Critical patent/GB2417290B/en
Publication of GB0418569D0 publication Critical patent/GB0418569D0/en
Publication of GB2417290A publication Critical patent/GB2417290A/en
Application granted granted Critical
Publication of GB2417290B publication Critical patent/GB2417290B/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K6/00—Arrangement or mounting of plural diverse prime-movers for mutual or common propulsion, e.g. hybrid propulsion systems comprising electric motors and internal combustion engines ; Control systems therefor, i.e. systems controlling two or more prime movers, or controlling one of these prime movers and any of the transmission, drive or drive units Informative references: mechanical gearings with secondary electric drive F16H3/72; arrangements for handling mechanical energy structurally associated with the dynamo-electric machine H02K7/00; machines comprising structurally interrelated motor and generator parts H02K51/00; dynamo-electric machines not otherwise provided for in H02K see H02K99/00
    • B60K6/20—Arrangement or mounting of plural diverse prime-movers for mutual or common propulsion, e.g. hybrid propulsion systems comprising electric motors and internal combustion engines ; Control systems therefor, i.e. systems controlling two or more prime movers, or controlling one of these prime movers and any of the transmission, drive or drive units Informative references: mechanical gearings with secondary electric drive F16H3/72; arrangements for handling mechanical energy structurally associated with the dynamo-electric machine H02K7/00; machines comprising structurally interrelated motor and generator parts H02K51/00; dynamo-electric machines not otherwise provided for in H02K see H02K99/00 the prime-movers consisting of electric motors and internal combustion engines, e.g. HEVs
    • B60K6/22—Arrangement or mounting of plural diverse prime-movers for mutual or common propulsion, e.g. hybrid propulsion systems comprising electric motors and internal combustion engines ; Control systems therefor, i.e. systems controlling two or more prime movers, or controlling one of these prime movers and any of the transmission, drive or drive units Informative references: mechanical gearings with secondary electric drive F16H3/72; arrangements for handling mechanical energy structurally associated with the dynamo-electric machine H02K7/00; machines comprising structurally interrelated motor and generator parts H02K51/00; dynamo-electric machines not otherwise provided for in H02K see H02K99/00 the prime-movers consisting of electric motors and internal combustion engines, e.g. HEVs characterised by apparatus, components or means specially adapted for HEVs
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D35/00—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for
    • F02D35/02—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for on interior conditions
    • F02D35/027—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for on interior conditions using knock sensors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D13/00—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing
    • F02D13/02—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing during engine operation
    • F02D13/0203—Variable control of intake and exhaust valves
    • F02D13/0215—Variable control of intake and exhaust valves changing the valve timing only
    • F02D13/0219—Variable control of intake and exhaust valves changing the valve timing only by shifting the phase, i.e. the opening periods of the valves are constant
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D13/00—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing
    • F02D13/02—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing during engine operation
    • F02D13/0261—Controlling the valve overlap
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D23/00—Controlling engines characterised by their being supercharged
    • 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
    • F02D41/0002—Controlling intake air
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D9/00—Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits
    • F02D9/02—Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits concerning induction conduits
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
    • F02P5/00—Advancing or retarding ignition; Control therefor
    • F02P5/02—Advancing or retarding ignition; Control therefor non-automatically; dependent on position of personal controls of engine, e.g. throttle position
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
    • F02P5/00—Advancing or retarding ignition; Control therefor
    • F02P5/04—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K6/00—Arrangement or mounting of plural diverse prime-movers for mutual or common propulsion, e.g. hybrid propulsion systems comprising electric motors and internal combustion engines ; Control systems therefor, i.e. systems controlling two or more prime movers, or controlling one of these prime movers and any of the transmission, drive or drive units Informative references: mechanical gearings with secondary electric drive F16H3/72; arrangements for handling mechanical energy structurally associated with the dynamo-electric machine H02K7/00; machines comprising structurally interrelated motor and generator parts H02K51/00; dynamo-electric machines not otherwise provided for in H02K see H02K99/00
    • B60K6/20—Arrangement or mounting of plural diverse prime-movers for mutual or common propulsion, e.g. hybrid propulsion systems comprising electric motors and internal combustion engines ; Control systems therefor, i.e. systems controlling two or more prime movers, or controlling one of these prime movers and any of the transmission, drive or drive units Informative references: mechanical gearings with secondary electric drive F16H3/72; arrangements for handling mechanical energy structurally associated with the dynamo-electric machine H02K7/00; machines comprising structurally interrelated motor and generator parts H02K51/00; dynamo-electric machines not otherwise provided for in H02K see H02K99/00 the prime-movers consisting of electric motors and internal combustion engines, e.g. HEVs
    • B60K6/42—Arrangement or mounting of plural diverse prime-movers for mutual or common propulsion, e.g. hybrid propulsion systems comprising electric motors and internal combustion engines ; Control systems therefor, i.e. systems controlling two or more prime movers, or controlling one of these prime movers and any of the transmission, drive or drive units Informative references: mechanical gearings with secondary electric drive F16H3/72; arrangements for handling mechanical energy structurally associated with the dynamo-electric machine H02K7/00; machines comprising structurally interrelated motor and generator parts H02K51/00; dynamo-electric machines not otherwise provided for in H02K see H02K99/00 the prime-movers consisting of electric motors and internal combustion engines, e.g. HEVs characterised by the architecture of the hybrid electric vehicle
    • B60K6/48—Parallel type
    • 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
    • F02D41/0002—Controlling intake air
    • F02D2041/0015—Controlling intake air for engines with means for controlling swirl or tumble flow, e.g. by using swirl valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
    • F02P5/00—Advancing or retarding ignition; Control therefor
    • F02P5/04—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions
    • F02P5/145—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions using electrical means
    • F02P5/15—Digital data processing
    • F02P5/152—Digital data processing dependent on pinking
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/40—Engine management systems
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/62—Hybrid vehicles

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Output Control And Ontrol Of Special Type Engine (AREA)
  • Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)

Abstract

Apparatus for reducing knock in an internal combustion engine having a cylinder, an inlet for allowing air into the cylinder and an adjustable valve for restricting the flow of air through the inlet into the cylinder, the apparatus comprising: a sensor for sensing conditions in the engine; and a control unit arranged to determine whether the sensed conditions meet predefined criteria indicative of a likelihood of knock, and if so, adjusting the valve to reduce the flow of air to the engine, thereby reducing the likelihood of knock. An engine management unit 13 may receive inputs from accelerator pedal position sensor 14, engine speed sensor 15, knock sensors 16 and temperature sensors 17. In response, the engine management unit 13 controls the activation of the spark plugs 8, the timing and quantity of fuel injection and the position of each throttle valve 12. The ignition timing may be adjusted to reduce the likelihood of knock. The compression ratio may be high, eg 13.5:1. The engine may be used at part-load eg in a hybrid vehicle also having an electric motor. The throttle butterflies 12 may be located close to the cylinders so that they promote swirl and turbulence.

Description

241 7290 306656.GB
ENGINE CONTROL
This invention relates to charging and knock control in internal combustion engines.
Internal combustion engines comprise one or more chambers in which fuel is burned to form gas which causes expansion inside the chamber, forcing a piston to move and turn a crankshaft. One problem that faces designers of internal combustion engines is optimization of the compression ratio, i.e. the ratio between the maximum and minimum volumes of the chamber as the piston moves. It is preferable for the compression ratio to be as high as possible, since that improves the efficiency of the engine. However, if the compression ratio is too high then as the piston moves so as to reduce the volume of the chamber it can cause knocking (due to preignition or detonation) before the fuel has been ignited by the engine's ignition system. For this reason, most petrol engines are designed to use the highest compression ratio that avoids knock anywhere in its operating range.
Knock is most likely at full throttle when the engine is developing its peak torque.
Therefore, this approach results in the engine having the maximum compression ratio for those high load conditions, but a lower compression ratio than could be used under part load conditions. As a result, this approach compromises fuel efficiency at part load. At part load the intake of fuel and oxygen to the engine is restricted by the throttle(s) and so the effective volumetric efficiency of the engine is reduced. This is highly significant for overall fuel economy because engines are normally operated at part load for most of the time.
A number of approaches have been adopted to address this problem. At least one engine (the Jaguar V12 HE) has been designed with a relatively high compression ratio, and with an arrangement to severely retard the ignition at high loads so as to avoid knock. Other engines (e.g. some produced by Saab and Maserati) are turbocharged and have been equipped with control units that prevent knock by moderating the boost pressure so as to reduce the cylinder charge and thus the effective compression ratio when necessary. This latter approach is not suitable for normally aspirated engines.
One reason why diesel engines can achieve relatively high efficiency is that there is no need to restrict the compression ratio, and so they can be designed to have a high compression ratio at part load.
There is therefore a need for an improved means of operating an engine in order to enhance efficiency.
According to the present invention there is provided apparatus for reducing knock in an internal combustion engine having a cylinder, an inlet for allowing air into the cylinder and an adjustable valve for restricting the flow of air through the inlet into the cylinder, the apparatus comprising: a sensor for sensing conditions in the engine; and a control unit arranged to determine whether the sensed conditions meet predefined criteria indicative of a likelihood of knock, and if so, adjusting the valve to reduce the flow of air to the engine, thereby reducing the likelihood of knock.
Preferably the predefined criteria include an occurrence of knock detected in the engine, most preferably in a pre-determined time or time- related measure (e.g. revolutions of the engine) previously. Preferably the predefined criteria include the engine speed exceeding a predefined minimum threshold engine speed. The predefined criteria may include the air in the inlet falling below a predefined minimum temperature.
The sensed conditions may include input from an indicator indicating the setting of a user-operable accelerator control for varying the output power from the engine.
According to a second aspect of the invention there is provided a system for reducing knock comprising: an internal combustion engine having a cylinder, an inlet for allowing air into the cylinder and an adjustable valve for restricting the flow of air through the inlet into the cylinder; a sensor for sensing conditions in the engine; and a control unit arranged to determine whether the sensed conditions meet predefined criteria indicative of a likelihood of knock, and if so, adjusting the valve to reduce the flow of air to the engine, thereby reducing the likelihood of knock.
The compression ratio of the engine may be at least 10:1, more preferably 12:1 or more, and most preferably 14:1 or more.
The system may comprise an additional power source for complementing the internal combustion engine. The additional power source may be an electric motor.
The valve is preferably located such that, when the valve is partly closed, the air turbulence occurring when air flows past the valve is such as to improve the mixture of fuel with the air. This may, for example, be due to the proximity of the valve to the cylinder and/or to a location at which fuel is injected into the air.
The control unit is preferably arranged so that if the sensed conditions are determined to meet the predefined criteria it adjusts the ignition timing of the engine so as to reduce the likelihood of knock.
According to a third aspect of the present invention there is provided a method for reducing knock in an internal combustion engine having a cylinder, an inlet for allowing air into the cylinder and an adjustable valve for restricting the flow of air through the inlet into the cylinder, the method comprising: sensing conditions in the engine; determining whether the sensed conditions meet predefined criteria indicative of a likelihood of knock, and if so: adjusting the valve to reduce the flow of air to the engine, thereby reducing the likelihood of knock.
The present invention will now be described by way of example with reference to the accompanying drawings. In the accompanying drawings: figure 1 is a schematic diagram of an internal combustion engine.
Figure 1 shows an internal combustion engine. The engine comprises an engine block 1 defining cylinders 2. Pistons 3 are movable in the cylinders and are connected by connecting rods 4 to a crankshaft 5. Each cylinder has at least one inlet valve 6, exhaust valve 7, spark plug 8 and fuel injector 9 which is connected to a pressurised fuel line 10. An inlet manifold 11 is connected to the inlets of the cylinders, with an individual throttle butterfly valve 12 provided for each cylinder.
A management unit 13 controls the operation of the engine. The management unit receives inputs from sources that include an accelerator pedal position sensor 14, an engine speed sensor 15, knock sensors 16 (usually one or two per engine), and one or more temperature sensors 17 located at appropriate positions on or within the engine. The outputs of the temperatures sensors can be used in the normal way, e.g. to adjust by means of the engine management unit the engine fuelling of the engine so as to accommodate variations in air temperature, oil temperature and coolant temperature. Using a pre-programmed control scheme the management unit processes those inputs to generate outputs that control the activation of the spark plugs 8, the timing and quantity of fuel injection by the injectors 9 and the position of each throttle valve 12. Throttle valves can be individually controlled (and may be in certain circumstances). However a preferred mode of operation is to operate a bank of throttle valves by means of a single actuator that is connected to all the valves of that bank by means such as a spindle or slide. Thus a bank of cylinders could be controlled in response to conditions sensed for the cylinder in the bank that is most prone to knock.
The engine has a relatively high compression ratio: for example 13. 5:1which is capable of causing knock during operation. However, knock is inhibited by the control scheme of the management unit, as will be described below. The effect of this is that the engine can be significantly more efficient than conventional engines under part load (due to its relatively high compression ratio), without suffering from excessive knock.
The control scheme of the management unit is arranged so that if it detects circumstances in which knock is likely in a cylinder it closes the throttle valve for that cylinder or bank of cylinders to some extent. This reduces the charge in that cylinder and inhibits knock. A likelihood of knock may be determined from the operating conditions of the engine (e. g. speed and load) or from the detection of knock by one of the knock sensors.
This approach to knock limitation might appear unfavourable because it might be expected to severely limit the output of the engine. However, this can be mitigated in a number of ways.
First, if the engine is employed in a situation in which it will operate predominantly in conditions of part load then the performance of the engine under full load is less significant. This can be achieved by sizing the engine so that even at part load it can fulfil the expected normal power requirements and/or by supplementing it with an additional power source that can be called upon at times of peak load. One example of the latter is in a hybrid vehicle that has an electric motor that can provide power to assist the internal combustion engine.
Second, if the throttle butterflies 12 are located close to the cylinders then as the throttle butterflies close and restrict the flow of air into the cylinders the swirl and turbulence of the air will increase and the temperature of the air decrease. This means that the mixture of the fuel with the air is improved, increasing the effectiveness of the charge that can be used.. Also, the restriction of the air flow causes an increase in air speed, which reduces the temperature of the air, increasing the charge density and reducing combustion chamber temperature and thus the propensity to knock.. The fuel injectors are preferably located so that the fuel is injected directly into the turbulent flow as this can provide good atomization, which enhances efficiency and cold starting and reduces harmful exhaust emissions.
Individual throttle butterflies located close to the inlets to the cylinders are advantageous for the reasons set out above, and also because they allow for a fast response to the onset of knock. However, fewer throttle valves, which could be shared between two or more cylinders and could be located further from the cylinders, could be used.
The control scheme operated by the management unit may take one of two broad types.
In the first type, the unit is pre-programmed with a general control scheme according to which the greater the demand for power (as indicated by the setting of the accelerator) the greater the flow of fuel and air that is allowed into the cylinders.
When knock is detected in a cylinder the general control scheme is overridden for that cylinder or group and the throttle valve serving that cylinder is closed somewhat, to a position that is more restrictive of air flow into the cylinder than would be the case under the general control scheme for the current setting of the accelerator and current conditions as indicated by other sensors that provide inputs to the control unit. After a pre-determined time, for example 0.1s or a specific number of engine revolutions, say 3. the general control scheme is resumed. If the engine did not have individual knock sensors and throttle butterflies for each cylinder then the control scheme would be overridden in a similar way for all cylinders.
In the second type of scheme, the management unit is pre-programmed with a general control scheme that includes automatic provision for closing of the throttle valves under conditions that would be expected to cause knock. This scheme is characterized in that the flow of air into the cylinders does not continue to increase as the demand for power (as indicated by the setting of the accelerator) increases.
Instead, as a result of the action of the throttle valves it remains constant or even decreases when knock would otherwise be likely.
In addition to restricting air flow to the engine under conditions where knock is likely, the management unit may also adjust the ignition timing, for example by retarding the ignition.
If the engine is operating as part of a hybrid power system, in which it can be augmented by another supplementary power source such as an electric motor, the management unit is preferably capable of causing the power supplied by the supplementary power source to increase when the throttle valves are closed or under conditions where they are likely to be closed. This can mitigate any overall reduction of power due to the closing of the valves, and can reduce the demand for power from the engine which may further reduce the chance of knock. Thus the present invention can also help to improve the overall efficiency of a hybrid power system comprising an internal combustion engine and a further power source capable of augmenting the power output of the engine. The further power source could, for example, be an electric motor or a hydraulic power source. The overall efficiency is dependent on the combined efficiency of the engine and the further power source as they operate together. With the engine operated according to the principles described above a particularly high compression ratio (15:1, for instance) can be used, with the engine's output being supplemented by the further power source when peak power is required. This allows a significant increase in overall efficiency (since the engine is operating more efficiently under part load) without loss of peak power.
The management unit 13 is suitably an electronic unit, and the throttle valves 12 are preferably fitted with electric position actuators 18 whereby their positions can be controlled by the management unit.
The present invention is especially applicable to petrol engines, but could be used in internal combustion engines that run on other fuels. In the case of petrol engines, the invention is especially applicable for engines that have a compression ratio greater than 10 to 1.
The applicant hereby discloses in isolation each individual feature described herein and any combination of two or more such features, to the extent that such features or combinations are capable of being carried out based on the present specification as a whole in the light of the common general knowledge of a person skilled in the art, irrespective of whether such features or combinations of features solve any problems disclosed herein, and without limitation to the scope of the claims. The applicant indicates that aspects of the present invention may consist of any such individual feature or combination of features. In view of the foregoing description it will be evident to a person skilled in the art that various modifications may be made within the scope of the invention.

Claims (14)

1. Apparatus for reducing knock in an internal combustion engine having a cylinder, an inlet for allowing air into the cylinder and an adjustable valve for restricting the flow of air through the inlet into the cylinder, the apparatus comprising: a sensor for sensing conditions in the engine; and a control unit arranged to determine whether the sensed conditions meet predefined criteria indicative of a likelihood of knock, and if so, adjusting the valve to reduce the flow of air to the engine, thereby reducing the likelihood of knock.
2. Apparatus according to claim 1 wherein the predefined criteria include an occurrence of knock.
3. Apparatus according to claim 1 or claim 2 wherein the predefined criteria include the engine speed exceeding a predefined minimum engine speed.
4. Apparatus according to any preceding claim wherein the predefined criteria include the air in the inlet falling below a predefined minimum temperature.
5. Apparatus according to any preceding claim wherein the sensed conditions include input from an indicator indicating the setting of a user-operable accelerator control for varying the output power from the engine.
6. A system for reducing knock comprising: an internal combustion engine having a cylinder, an inlet for allowing air into the cylinder and an adjustable valve for restricting the flow of air through the inlet into the cylinder; a sensor for sensing conditions in the engine; and a control unit arranged to determine whether the sensed conditions meet predefined criteria indicative of a likelihood of knock, and if so, adjusting the valve to reduce the flow of air to the engine, thereby reducing the likelihood of knock.
7. A system according to claim 6 wherein the compression ratio of the engine is fixed at at least 10:1.
8. A system according to claim 7 wherein the compression ratio of the engine is fixed at at least 14:1.
9. A system according to any of claims 6 to 8 further comprising an additional power source for complementing the internal combustion engine.
10.A system according to claim 9 wherein the additional power source is an electric motor.
11.A system according to any preceding claim wherein the valve is located sufficiently close to the cylinder and/or an injector of fuel into the air that, when the valve is partly closed, the air turbulence occurring when air flows past the valve is such as to improve the mixture of fuel with the air.
12.A system according to any preceding claim wherein when the sensed conditions are determined to meet the predefined criteria the control unit is arranged to adjust the ignition timing of the engine so as to reduce the likelihood of knock.
13.A method for reducing knock in an internal combustion engine having a cylinder, an inlet for allowing air into the cylinder and an adjustable valve for restricting the flow of air through the inlet into the cylinder, the method comprising: sensing conditions in the engine; determining whether the sensed conditions meet predefined criteria indicative of a likelihood of knock, and if so: adjusting the valve to reduce the flow of air to the engine, thereby reducing the likelihood of knock.
14. Apparatus substantially as described herein with reference to the accompanying drawing.
GB0418569A 2004-08-19 2004-08-19 Reducing knock in internal combustion engines with an additional power source Expired - Fee Related GB2417290B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB0418569A GB2417290B (en) 2004-08-19 2004-08-19 Reducing knock in internal combustion engines with an additional power source

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB0418569A GB2417290B (en) 2004-08-19 2004-08-19 Reducing knock in internal combustion engines with an additional power source

Publications (3)

Publication Number Publication Date
GB0418569D0 GB0418569D0 (en) 2004-09-22
GB2417290A true GB2417290A (en) 2006-02-22
GB2417290B GB2417290B (en) 2008-10-22

Family

ID=33042355

Family Applications (1)

Application Number Title Priority Date Filing Date
GB0418569A Expired - Fee Related GB2417290B (en) 2004-08-19 2004-08-19 Reducing knock in internal combustion engines with an additional power source

Country Status (1)

Country Link
GB (1) GB2417290B (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0266047A2 (en) * 1986-09-26 1988-05-04 The British Petroleum Company p.l.c. Process for the preparation of gasoline components from olefins
FR2924758A1 (en) * 2007-12-10 2009-06-12 Peugeot Citroen Automobiles Sa Helical turbulent gas flow controlling method for engine i.e. oil engine, of motor vehicle, involves increasing value of number of swirls in gas flow with respect to reference value, when temperature is less than minus ten degree Celsius
WO2015092451A1 (en) * 2013-12-20 2015-06-25 Pakai Tibor Device and procedure for increasing the efficiency of internal combustion engines

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8483937B2 (en) * 2010-07-29 2013-07-09 Ford Global Technologies, Llc Method and system for controlling fuel usage
CN111997767B (en) * 2020-09-04 2021-10-22 东风汽车集团有限公司 Method and device for controlling air inflow for inhibiting knocking under pre-ignition and high-intensity knocking

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60261965A (en) * 1984-06-07 1985-12-25 Daihatsu Motor Co Ltd Knocking controller
JPS61167135A (en) * 1985-01-18 1986-07-28 Mitsubishi Motors Corp Knocking controller
JPS62199926A (en) * 1986-02-28 1987-09-03 Toyota Motor Corp Knocking controller for internal combustion engine associated with supercharger
JPS62251451A (en) * 1986-04-23 1987-11-02 Nissan Motor Co Ltd Knocking control device for internal combustion engine
JPS63143360A (en) * 1986-12-08 1988-06-15 Mazda Motor Corp Suction air quantity controller for engine
WO1996001939A1 (en) * 1994-07-12 1996-01-25 John Brengle Taylor A restricted induction reciprocating piston type internal combustion engine
JP2004360562A (en) * 2003-06-04 2004-12-24 Mitsubishi Electric Corp Control device for internal combustion engine

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60261965A (en) * 1984-06-07 1985-12-25 Daihatsu Motor Co Ltd Knocking controller
JPS61167135A (en) * 1985-01-18 1986-07-28 Mitsubishi Motors Corp Knocking controller
JPS62199926A (en) * 1986-02-28 1987-09-03 Toyota Motor Corp Knocking controller for internal combustion engine associated with supercharger
JPS62251451A (en) * 1986-04-23 1987-11-02 Nissan Motor Co Ltd Knocking control device for internal combustion engine
JPS63143360A (en) * 1986-12-08 1988-06-15 Mazda Motor Corp Suction air quantity controller for engine
WO1996001939A1 (en) * 1994-07-12 1996-01-25 John Brengle Taylor A restricted induction reciprocating piston type internal combustion engine
JP2004360562A (en) * 2003-06-04 2004-12-24 Mitsubishi Electric Corp Control device for internal combustion engine

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0266047A2 (en) * 1986-09-26 1988-05-04 The British Petroleum Company p.l.c. Process for the preparation of gasoline components from olefins
EP0266047A3 (en) * 1986-09-26 1988-10-26 The British Petroleum Company p.l.c. Process for the preparation of gasoline components from olefins
FR2924758A1 (en) * 2007-12-10 2009-06-12 Peugeot Citroen Automobiles Sa Helical turbulent gas flow controlling method for engine i.e. oil engine, of motor vehicle, involves increasing value of number of swirls in gas flow with respect to reference value, when temperature is less than minus ten degree Celsius
WO2015092451A1 (en) * 2013-12-20 2015-06-25 Pakai Tibor Device and procedure for increasing the efficiency of internal combustion engines

Also Published As

Publication number Publication date
GB2417290B (en) 2008-10-22
GB0418569D0 (en) 2004-09-22

Similar Documents

Publication Publication Date Title
CN108779727B (en) Control device for compression self-ignition engine
US6817349B2 (en) Control system and method and engine control unit for compression ignition internal combustion engine
US7870844B2 (en) Control system and method for internal combustion engine
JP6848888B2 (en) Engine capable of suppressing strong knock
WO1997000378A1 (en) Lambda control by skip fire of unthrottled gas fueled engines
CN109424419A (en) The control device of compression ignition formula engine
JP6848889B2 (en) engine
JP4107099B2 (en) High compression ratio supercharging lean burn engine operation mode controller
CN107849988B (en) Control device for internal combustion engine
US10294875B2 (en) Control device for adjusting first and second fuel ratios
Silva et al. Split-injection in a downsized ethanol SIDI engine aiming to mitigate pre-ignition
GB2417290A (en) Reducing knock in i.c. engines
RU152553U1 (en) VEHICLE SYSTEM
CN115839273A (en) Method for controlling a hydrogen internal combustion engine
JP7310574B2 (en) engine controller
JP2556778B2 (en) Engine with fuel usage discriminator
CN111706439A (en) System and method for cylinder deactivation in a dedicated EGR engine
JP7263905B2 (en) engine controller
JP7263906B2 (en) engine controller
JP7298282B2 (en) engine controller
JP7056477B2 (en) Spark plug abnormality judgment device
JP7188242B2 (en) CONTROL DEVICE AND CONTROL METHOD FOR INTERNAL COMBUSTION ENGINE
JP6777120B2 (en) Engine control
JP7056476B2 (en) Spark plug abnormality judgment device
JPS60230523A (en) Knocking preventing apparatus for variable compression-ratio type engine

Legal Events

Date Code Title Description
732E Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977)
732E Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977)

Free format text: REGISTERED BETWEEN 20110804 AND 20110810

PCNP Patent ceased through non-payment of renewal fee

Effective date: 20120819