Classifications

• • 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
  • F02D13/06—Cutting-out cylinders
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D17/00—Controlling engines by cutting out individual cylinders; Rendering engines inoperative or idling
  • F02D17/02—Cutting-out
• • 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
  • F02D41/008—Controlling each cylinder individually
  • F02D41/0087—Selective cylinder activation, i.e. partial cylinder operation
• • 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
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D17/00—Controlling engines by cutting out individual cylinders; Rendering engines inoperative or idling
  • F02D17/02—Cutting-out
  • F02D17/023—Cutting-out the inactive cylinders acting as compressor other than for pumping air into the exhaust system
  • F02D17/026—Cutting-out the inactive cylinders acting as compressor other than for pumping air into the exhaust system delivering compressed fluid, e.g. air, reformed gas, to the active cylinders other than during starting
• • 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
  • F02D2041/001—Controlling intake air for engines with variable valve actuation
• • 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
  • F02D2041/001—Controlling intake air for engines with variable valve actuation
  • F02D2041/0012—Controlling intake air for engines with variable valve actuation with selective deactivation of cylinders
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D2250/00—Engine control related to specific problems or objectives
  • F02D2250/28—Control for reducing torsional vibrations, e.g. at acceleration
• • 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
  • F02D41/008—Controlling each cylinder individually
• • 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
  • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
  • F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
• • 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
  • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
  • F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
  • F02D41/1454—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an oxygen content or concentration or the air-fuel ratio
• • 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
  • F02D41/1497—With detection of the mechanical response of the engine
• • 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
  • F02D41/1497—With detection of the mechanical response of the engine
  • F02D41/1498—With detection of the mechanical response of the engine measuring engine roughness
• • 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

Definitions

• the present invention relates to a method for controlling an internal combustion engine according to the preamble of claim 1 , an internal combustion engine controlled by such a method according to the preamble of claim 21 and a vehicle comprising such an internal combustion engine according to the preamble of claim 22.
• shut off the fuel supply to some cylinders of the internal combustion engine to reduce environmental impact.
• Shutting off or deactivating the fuel still implies that air is passing the fuel de- activated cylinders without any combustion which means that the exhaust treatment system will be cooled.
• the treatment system must reach an operating temperature in the range 200° C - 600° C in order to satisfactory reduce the emissions from the engine.
• the exhaust and inlet valves of the deactivated cylinders can be closed.
• the pressure in the deactivated cylinders gives rise to a torque pulse per revolution per cylinder until the pressure, due to leakage, becomes so low in these cylinders that no significant torque is ob- tained from them.
• the vibrations can be reduced if either the exhaust or the intake valves in the deactivated cylinders are kept closed and the active valves do both the exhaust and inlet lift events. Torque pulses will then be obtained from the compression/expansion pressure in the deactivated cylinders. This results in essentially the same vibration level as when the only measure is shutting off the fuel to the deactivated cylinders. Moreover, the mass flow to the exhaust treatment is reduced and the exhaust temperature is thereby significantly increased.
• the engine exhaust treatment system By controlling the exhaust or inlet valves of the deactivated cylinders, so that they will remain closed during all strokes, the engine exhaust treatment system will not be cooled because no air is passed to the exhaust treatment system from the deactivated cylinders.
• cylinder deactivation with closed intake and/or exhaust valves might be required to prevent the exhaust temperature to fall below its critical limit. This is done in order to maintain the conversion of the exhaust emissions in the exhaust treatment system.
• the object of the present invention is thus to provide a method for controlling an internal combustion engine in which vibrations resulting from a zero flow of air supplied to the exhaust gas system from one or more of the cylinders are reduced.
• a further object of the present invention is to provide a method for controlling an internal combustion engine which reduces tail pipe exhaust emissions when a zero flow of air supplied to the exhaust gas system from one or more of the cylinders is implemented.
• the exhaust gas properties based on a diagnose of oxygen content and/or tempera- ture of the exhaust gases are compared with predetermined exhaust gas properties.
• vibrations in the internal combustion engine based on crankshaft torsional vibrations, or other engine vibrations are compared with a predetermined vibration value of the internal combustion engine.
• the internal combustion engine has preferably separate valve control means for the inlet and exhaust valves. At an operating condition of the internal combustion engine corresponding to normal load the control device controls the exhaust valves to open at the bottom dead centre of the termination of the expansion stroke and so that they close at top dead centre for start of the intake stroke, and the inlet valves open at the top dead centre when the intake stroke starts and close at the bottom dead centre when the compression stroke starts.
• the intake valves and exhaust valves in one or more of the cylinders are controlled to produce a zero flow of air from the inlet side to the exhaust side of the cylinder when the pistons move back and forth in these cylinders.
• the fuel injection is controlled to supply a first volume of fuel to the cylinders with zero flow of air, and also ensure that a second volume of fuel is supplied to the other cylinders.
• the second fuel volume is greater than the first volume of fuel, which results in a reduction of vibrations of the internal combustion engine.
• a different distribution between the first and second fuel volume is advantageous. For example they may be equal, or the first volume of fuel may be greater than the second volume of fuel.
• one of the first intake valves is controlled to open at a bottom dead centrecentre of the piston in the first cylinder, between an expansion stroke and an exhaust stroke, and to close at a top dead centre of the piston in the first cylinder between an exhaust stroke and an intake stroke.
• the other of the first intake valves is controlled to open when one of the first intake valves closes, and to close at bottom dead centre between an inlet stroke and a compression stroke, and the first exhaust valves are controlled so that they remain closed during all strokes of the engine.
• one of the first exhaust valves is controlled to open at a bottom dead centre of the piston in the first cylinder, between an expansion stroke and an exhaust stroke, and to close at top dead centre of the piston in the first cylinder between an exhaust stroke and an intake stroke
• the other of the first exhaust valves is controlled to open when one of the first exhaust valves closes, and to close at bottom dead centre between an inlet stroke and a compression stroke
• the first intake valves are controlled so that they remain closed during all strokes of the engine.
• Such combustion engine ensures that the vibrations caused by the fact that no air is supplied to the exhaust gas system from one or more of the cylinders, are effectively reduced.
• Such an internal combustion engine also increases the exhaust gas temperature upstream the exhaust treatment system, thereby facilitating conversion of emissions.
• the pressure in the active cylinders will reduce and adapt to a pressure level which substantially provide the same torque contribution to the crankshaft vs. crank angle, as the cylinders from which no air is supplied to the exhaust gas system.
• the vibrations will be effectively reduced.
• vibrations of the order 1 ,5 are created due to loss of torque contribution from the deactivated cylinders.
• the vibrations of order 1 ,5 are suppressed by maintaining compression and expansion pressure in the deactivated cylinders.
• the invention is particularly effective for reducing the low-frequency vibrations that arise during idle operation of the engine.
• the sum of torque contributions from the pressure in all cylinders should not contain the order of 1 ,5. This may be achieved by reducing the difference between the torque contributions from the deactivated and the activated cylinders by reducing the air mass trapped in the active cylinders, while trapped air mass in the deactivated cylinders may be in- creased. From the active cylinders air is supplied to the exhaust gas system. How much reduction of the trapped air mass in the active cylinders that is required depends on the load and speed of the engine, and is preferably controlled so that the reduction of vibrations at idle has priority, however exhaust emissions always have top priority. Torque vs.
• crank angle, produced by the active cylinders is a function of cylinder pressure, cylinder bore and the crank mechanism, i.e. connecting rod length, stroke of the crankshaft, and crankshaft position.
• the crank mechanism cannot be affected. Therefore, the cylinder pressure is used to optimize the torque contribution.
• the crankshaft position approximately 25 degrees before and after top dead centre because the combination of high cylinder pressure and the position of the crank mechanism results in high torque.
• a vehicle provided with such an internal combustion engine will avoid cooling of the exhaust treatment system and ensure that vibrations due to the deactivation of the cylinders are effectively reduced.
• the comfort of the persons travelling in the vehicle increases when the vibrations of the vehicle decrease compared to previously known concept for cylinder deactivation.
• the invention also relates to a computer program and a computer program product for performing the method according to the present invention.
• Fig. 1 shows schematically a vehicle in a side view, with an engine controlled by the method according to the present invention
• Fig. 2 shows schematically a view from above of an engine controlled by the method according to the present invention
• Fig. 3 shows a sectional view through the line ll-ll in fig. 2
• Fig. 4a-d shows graphs of the crankshaft torque from each cylinder of an engine controlled by the method according to the present invention
• Fig. 5 shows graphs of the pressure in a cylinder vs. crank position of an engine controlled by the method according to the present invention
• Fig. 6 shows graphs of the pressure in a cylinder vs. volume of an engine controlled by the method according to the present invention
• Fig. 7 shows a flow chart of the method for controlling an engine according to the present invention.
• Fig. 1 shows schematically a vehicle 1 in a side view, e.g. a truck, which comprises an internal combustion engine 2 controlled by the method according to the present invention.
• the engine 2 which may be a diesel engine, is connected to a gearbox 4 which is further connected to driving wheels 6 of the vehicle 1 via a propeller shaft 8.
• Fig. 2 shows a schematic view from above of an internal combustion engine 2 of a four-stroke type.
• the engine is a diesel engine that is powered by diesel fuel and comprises at least a first and second cylinder C1 , C4.
• the engine 2 of the embodiment disclosed in fig. 2 comprises six cylinders C1 - C6, which are arranged in a row in which a piston P1 - P6 is arranged in each cylinder C1 - C6 of the engine 2.
• the invention is applicable to any cylinder configuration and not limited to inline engines only.
• At least one first inlet valve 18 is provided in the first cylinder C1 and the first inlet valve 18 is in communication with an intake system 20.
• At least one first exhaust valve 24 is provided in the first cylinder C1 and the first exhaust valve 24 is in communication with an exhaust system 26.
• At least one second inlet valve 19 is provided in the second cylinder C4 and the second inlet valve 19 is in communication with the intake system 20.
• At least one second exhaust valve 25 is provided in the second cylinder C4 and the second exhaust valve 25 is in communication with the exhaust system 26.
• the inlet and exhaust valves are provided in the remaining cylinders C2, C3, C5, C6.
• a damper 23 may be arranged in the intake system 20, which damper 23 can be adjusted so that it restricts the air supply to the cylinders C4 - C6 of the engine 2.
• Fig. 3 shows a cross sectional view of the internal combustion engine 2 through the line ll-ll in Fig. 2.
• the piston P1 is via a connecting rod 14 connected to a crankshaft 16, which upon rotation of the crankshaft 16 reciprocates the piston P1 in the cylinder C1.
• At least a first valve control means in the form of a first cam shaft 22 is provided to control the first and second inlet valve 18, 19.
• At least one second valve control means in the form of a second camshaft 28 is arranged to control the first and second exhaust valve 24, 25.
• the valve control means comprises camshafts 22, 28, but it is however possible to use other types of valve instruments, such as hydraulic, pneumatic or electric valve control means.
• the crankshaft 16 is arranged to control each camshaft 22, 28.
• At least one control device 34 is provided between the crankshaft 16 and each camshaft 22, 28 for controlling the first inlet valve 18 and the first exhaust valve 24, so that no air is supplied to the exhaust system 26 from the first cylinder C1 when the first piston P1 moves back and forth in the first cylinder C1 and when the first cylinder C1 is deactivated. Thus, a zero flow through the first cylinder C1 is created.
• the control device 34 is also arranged to control the internal combustion engine 2 so that the intake air mass in the second cylinder C4 decreases relative to the intake air mass in the first cylinder C1.
• the control device 34 is controlled so that the exhaust valves 24, 25 open at the bottom dead centre BDC for the termination of the expansion stroke and so that they close at the top dead centre TDC for start of the inlet stroke, and that the inlet valves 18, 19 open at the top dead centre TDC when the inlet stroke begins, and closes at bottom dead centre BDC when the compression stroke starts.
• two first and two second cam shafts 22, 28 may be provided in the internal combustion engine 2. This is advantageous if the engine 2 is of a V-type.
• a camshaft controller 30 is provided in the internal combustion engine 2.
• the crankshaft 16 controls each camshaft 22, 28 via a camshaft transmission 32.
• At least one control device 34 is provided between the crankshaft 16 and each camshaft 22, 28, so that the valves can be controlled to a position in which the inlet and exhaust valves 18, 19, 24, 25 are controlled so that no air is supplied to the exhaust system 26 when the pistons P1 - P3 move back and forth in the cylinders C1 - C3.
• a control device 34 is provided for each camshaft 22, 28.
• An electronic control unit 36 receives signals from various sensors (not shown) such as the absolute pressure in the intake manifold, the charge air temperature, air mass flow, throttle position, engine speed and engine load. The control unit 36 affects the control device 34, which adjusts the valves 18, 19, 24, 25 opening and closing times relative to the position of the crankshaft angle ⁇ .
• a computer program P controls the internal combustion engine 2, wherein said computer program P comprises program code for making the electronic control unit 36 or another computer 46 connected to the electronic control unit 36 performing the steps of the method according to the present invention.
• the invention also relates to a computer programme product which is directly storable in an internal memory M into the electronic control unit 36 or the other computer 46.
• a fuel pump 41 is connected to injection means 43 arranged in each cylinder C1 - C6. The injection means 43 injecting fuel into the cylinders C1 - C6.
• Fig. 4 a - d show graphs of torque versus crankshaft angle ⁇ of an internal combustion engine 2 provided with six cylinders C1 - C6.
• the Y axis represents torque T from the cylinders C1 - C6.
• the X axis represents the crankshaft angle ⁇ and thereby the position of piston P1.
• Each positive torque pulse in Fig. 4a represents an expansion of cylinder C1 - C6, respectively. Every negative torque pulse represents a compression of cylinder C1 - C6, respectively.
• Fig. 4b three of the engine's six cylinders C1 - C3 has been deactivated while the remaining three cylinders C4 - C6 are still activated. In a deactivated cylinder no air is supplied to the exhaust gas system.
• no fuel is supplied to the deactivated cylinders C1 - C3.
• fuel and air are supplied to the cylinder corresponding to normal operation conditions of the engine 2. All valves in the three deactivated cylinders C1 - C3 are closed and the cylinders C1 - C3 have gradually deflated.
• a problem arises when one or more cylinders C1 - C3 is deactivated and the other cylinders C4 - C6 are activated. Then vibrations are generated by the combustion engine 2 due to a different frequency spectrum of expansions of the engine 2, since small or no torque pulses are obtained from the pressure in the deactivated cylinders C1 - C3.
• Fig. 4c the vibrations have to some extent been reduced by controlling the combustion engine 2 so that the same amount of gas is trapped in cylinders C1 - C3 as in cylinders C4 - C6, during the inlet stroke.
• cylinders C1 - C3 are controlled in such a way that the net flow of gas across these cylinders is zero.
• the air trapped in the deactivated cylinders C1 - C3 will be compressed and expanded and thereby transfer a torque to the crankshaft. This will change the order of vibrations from 1 ,5 to 3.
• Fig. 4c shows however that the positive torque pulse in the active cylinders C4 - C6 is higher than the positive torque pulse which builds up in the deactivated cylinders C1 - C3.
• This torque difference will cause vibrations in the engine 2, which become especially annoying when the engine 2 is operated at idle speed.
• the vibrations are generated by the lateral forces between the pistons P1 - P3 and cylinders C1 - C3, and in the bearings for the crankshaft 16.
• the torque of the active cylinders C4 - C6 will reduce and adapt to a pressure level substantially corresponding to the torque in the deactivated cylinders C1 - C3, as shown by the graph in Fig. 4d.
• the vibrations will be effectively reduced.
• vibrations of order 1 ,5 arises.
• the method according to the invention changes to the order of vibrations to 3 by maintaining compression and expansion pressure in the deactivated cylinders C1 - C3.
• the inlet valves 19 in the active cylinders C4 - C6 are controlled to reduce the intake air mass to the active cylinders C4 - C6. This is achieved by controlling the inlet valves 19 in the active cylinders C4 - C6 to close before or after the closing time of inlet valves 19 during normal operation of the internal combustion engine 2.
• the inlet and exhaust valves 18, 24 in one or more of the cylinders C1 - C3 are controlled to produce a zero flow of air from the inlet side to the exhaust side of the cylinder when the pistons move back and forth in these cylinders.
• the fuel injector is controlled to supply a first volume of fuel to the cylinders with zero flow of air during these cylinders expansion stroke, and also a second volume of fuel is supplied to the cylinders in which a flow of gas from the inlet side to the exhaust side is executed, during these cylinders expansion.
• the ratio between the first and second fuel volume can vary depending on the internal combustion engine and vehicle operating conditions.
• the first and second fuel volume may also be substantially equal.
• the graphs in Fig. 4 represent an internal combustion engine 2 of the four-stroke type, where within the crankshaft 16 rotates 720 ° CA and each piston P1 - P6 travels four strokes to complete a full cycle.
• Fig. 5 illustrates cylinder pressure vs. crankshaft position ⁇ of an internal combustion engine 2.
• the Y-axis represents the pressure p in the cylinder C1 , and in the cylinder C4.
• the X-axis represents the crankshaft position ⁇ and thus the position of the pis- ton P in the cylinder.
• Graph A in Fig. 5 illustrates the pressure in the deactivated cylinder C1 vs. crankshaft position ⁇ .
• Graph B illustrates the pressure in the active cylinder C4 vs. crankshaft position ⁇ .
• TDC top dead centre
• crank angle produced by the active cylinders C4 - C6 is a function of cylinder pressure, cylinder bore and the crank mechanism, i.e. connecting rod length, stroke of the crankshaft 16, and crankshaft position, ⁇ .
• the crank mechanism cannot be influenced, and therefore the cylinder pressure is used to optimize the addition of torque.
• the crank position approximately 25 degrees before and after piston top dead centre TDC, since the combination of high in-cylinder pressure, and the crank mechanism position will result in high torque.
• the second inlet valves are controlled to reduce the intake air mass to the active cylinders C4 - C6. This is achieved by controlling the inlet valves 19 in the activated cylinders C4 - C6 to close before or after the closing time of inlet valves 19 during normal operation of the internal combustion engine 2.
• the inlet valves 19 in the cylinders C4 - C6 are controlled to close in the range corresponding to 30° crankshaft angles before bottom dead centre (CA bBDC) to 30° crankshaft angles after bottom dead centre (CA aBDC), preferably at the bottom dead centre (aBDC).
• the inlet valves 19 in the cylinders C4 - C6 are controlled to close in the range corresponding to 30° CA aBDC to 90° CA aBDC, preferably 60° CA aBDC.
• the damper e.g. a throttle 23 arranged in the intake system 20 is activated. By closing the throttle 23 in order to restrict the air flow to the active cylinders C4 - C6 of engine 2 the trapped mass of air in the active cylinders C4 - C6 will decrease.
• the throttle 23 can be used in combination with the control of the intake valves 19 to the active cylinders C4 - C6.
• the intake valves of the deactivated cylinders C1 - C3 are con- trolled, according to a first embodiment, to open in the exhaust stroke and in the intake stroke, while the exhaust valves of the deactivated cylinders C1 - C3 are controlled to a closed position for all strokes.
• the exhaust valves 24 of the deactivated cylin- ders C1 - C3 are controlled to open in the exhaust stroke and in the intake stroke, while the intake valves of the deactivated cylinders C1 - C3 are controlled to a closed position for all strokes.
• the pressure in all cylinders C1 - C6 must be identical.
• the intake valves and exhaust valves of cylinders C1 - C3 are controlled so that a zero flow of air from the inlet side to the exhaust side is achieved, and so that no air is supplied to the exhaust system from these cylinders, when the pistons move back and forth in the cylinders C1 - C3.
• the fuel injectors 43 are controlled to supply a first volume of fuel to the cylinders C1 - C3 at TDCf (Top Dead Centre firing). A second volume of fuel is supplied to the cylinders C4 - C6 at TDCf for these cylinders.
• the pressure in the cylinders C1 - C3 will increase and be adapted to a pressure level which substantially corresponds to the pressure in the cylinders C4 - C6.
• the vibrations will be effectively reduced. If the first and second fuel volume are equal an essentially complete elimination of the order of 1 ,5 is achieved.
• the inlet valves 18 and 19 and the exhaust valves 24 and 25 in all cylinders C1 - C6 are kept closed so that no air is supplied to the exhaust system 26 from the cylinders C1 - C6 when the pistons P1 - P6 move back and forth in the cylinders C1 - C6.
• the fuel injectors 42 are controlled to supply fuel at TDCf to all of the cylinders C1 - C6, through which a zero flow of air from the inlet side to the exhaust side prevail.
• fuel is supplied during several consecutive expansion strokes in the cylinders C1 - C6. As a result the pressure in the cylinders C1 - C6 will increase in consecutive steps ⁇ 1 - ⁇ 3.
• the inlet valves 18 and 19 and the exhaust valves 24 and 25 in the cylinders C1 - C6 are controlled to an opening and closing procedure corresponding to a normal operation condition for the engine 2 so that fresh air is supplied to the cylinders C1 - C6. Thereafter, if the exhaust gas properties and/or exhaust temperature deviate from the predetermined exhaust gas properties and/or exhaust temperature the inlet valves 18 and 19 and the exhaust valves 24 and 25 in all cylinders C1 - C6 are kept closed so that no air is supplied to the exhaust system 26, and fuel is supplied during several consecutive expansion strokes in the cylinders C1 - C6.
• the method for controlling the internal combustion engine 2 of the present invention will be described along with the flowchart of Fig. 7, comprises the steps of:
• the method comprises the additional step: c) diagnosing vibrations of the internal combustion engine 2 and compare the vibrations with a predetermined value of vibrations of the internal combustion engine 2.
• Step b) and step c) are performed in any order or are performed substantially simul- taneously.
• the exhaust gas properties may for example be the amount of oxygen in the exhaust gases and/or the exhaust temperature of the exhaust gases.
• step a) information about the present air-fuel ratio A pres and present vibrations pres of the engine 2 are collected and the collected present air-fuel ratio A pre s is in step b) compared to a predetermined reference value for the air-fuel ratio A re f and the collected present value of vibrations V pr es is in step c) compared to a predetermined reference value for the vibrations V ref . If the exhaust gas properties deviate from the predetermined exhaust gas properties, i.e.
• a pres > A re f the first inlet valve 18 and the first exhaust valve 24 are controlled, so that no air is supplied to the exhaust system 26 from the first cylinder C1 when the first piston P1 moves back and forth in the first cylinder C1.
• a pre s A re t the first inlet valve 18 and the first exhaust valve 24 are controlled to open and close in accordance to normal engine operation condi- tions.
• the method comprises the additional step: f) reducing the intake air mass to the second cylinder C4 in relation to the intake air mass to the first cylinder C1 , if the vibra- tions in the internal combustion engine 2 are greater than the predetermined value for the vibrations in the internal combustion engine 2.
• step f) if the collected present value of vibrations V pre s in the internal combustion engine 2 is greater than the predetermined reference value for the vibrations V re f in the internal combustion engine 2, i.e. V pre s > V re f the intake air mass to the second cylinder C4 is reduced in relation to the intake air mass to the first cylinder C1.
• V pre s > V re f the intake air mass to the second cylinder C4 is reduced in relation to the intake air mass to the first cylinder C1.
• step f) the second inlet valve 9 is controlled to reduce the trapped mass of air in the second cylinder C4. This may be achieved by controlling the second inlet valve 19 to close before or after the time of closing of the second inlet valve 19 during normal operation of the combustion engine 2.
• the force transfer means 16 for controlling each valve control means 22, 28 is a crankshaft 16 and the second inlet valve 19 is controlled to close in the range corresponding to 30° CA bBDC to 30° CA aBDC, preferably at BDC.
• the force transfer means 16 for controlling each valve control means 22, 28 is a crankshaft 16 and the second inlet valve 19 is controlled to close in the range corresponding to 30° CA aBDC to 90° CA aBDC, preferably 60° CA aBDC.
• the first inlet valve 18 is in step e) preferably controlled to open during the exhaust stroke and the intake stroke, while the first exhaust valve 24 is controlled to a closed position during all strokes.
• the first exhaust valve 24 is in step e) preferably controlled to open during the exhaust stroke and the intake stroke, while the first inlet valve 18 is controlled to a closed position for all strokes.
• the supplied fuel to the engine 2 is diesel fuel. Since an engine 2 powered by diesel works according to the compression ignition principle, pistons, valves and valve timing are designed with a suitable geometry, so that a functional interaction between the pistons and valves is obtained.
• the method comprises the additional step: g) control respective valve 18,19,24,25 by means of two first and two second valve control means 22, 28.
• valve control means 22, 28 are camshafts 22, 28.
• the inlet and ex- haust valves are controlled and driven by a separate valve control device, which is in turn driven by the crankshaft.
• the respective valve control device has control means which controls the valve and thus the opening and closing times of the valve.
• the control device is preferably coupled to a control unit which controls the control device to a position which is adapted to the internal combustion engine operating conditions.
• the control unit also controls a fuel injection device that supplies fuel to the cylinders.
• the method comprises the additional steps:
• the pressure in the cylinders C1 - C3 will increase and be adapted to a pressure level substantially corresponding to the pressure in the cylinders C4 - C6.
• the ratio between the first and second fuel volume can vary depending on the combustion engine and operating conditions of the vehicle.
• the first and second volume of fuel may be substantially equal, but preferably the second volume of fuel is greater than the first volume of fuel, so that vibrations are effectively reduced.
• the method comprises the additional step:
• step j) control two inlet valves 18, 19 and two exhaust valves 24, 25 by means of respective valve control means 22, 28.
• the application of the invention may be very efficient, since the number of valves per cylinder affects the air flow and the filling and emptying of the cylinders.
• the method comprises the additional step: k) controlling the second inlet valve 19 and the second exhaust valve 25, so that no air is supplied to the exhaust system 26 from the second cylinder C4 when the second piston P4 moves back and forth in the second cylinder C4, if the exhaust gas properties deviate from the predetermined exhaust gas properties.
• step e) and k) fuel is supplied during several consecutive cycles in the first and second cylinders C1 , C4.
• the diagnosed exhaust gas properties comprises information about the present air- fuel ratio Apres and the predetermined exhaust gas properties comprises information about a predetermined reference value for the air-fuel ratio A re f and if the present air- fuel ratio Apres is less than the air-fuel ratio A re f the inlet and exhaust valves 18, 19, 24, 25 are controlled to open and close in accordance with normal operation of the com- bustion engine 2.
• the present invention also relates to a computer programme P (fig. 3) and a computer programme product for performing the steps of the method.
• the computer program P controls the internal combustion engine, wherein said computer program P comprises program code for making the electronic control unit 36 or another computer 46 connected to the electronic control unit 36 performing the steps of the method according to the present invention as mentioned herein, when said computer programme P is run on the electronic control unit 36 or another computer 46 connected to the electronic control unit 36.
• the computer programme product comprises a program code stored on a, by an electronic control unit 36 or another computer 46 connected to the electronic control unit 36 readable, media for performing the steps of the method according to the present invention as mentioned herein, when said computer programme P is run on the electronic control unit 36 or another computer 46 connected to the electronic control unit 36.
• the computer programme product is directly storable in an internal memory M into the electronic control unit 36 or another computer 46 connected to the electronic control unit 36, comprising a computer programme P for performing the steps of the method according to the present invention, when said computer pro- gramme P is run on the electronic control unit 36 or another computer 46 connected to the electronic control unit 36.

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

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• 2015
  • 2015-03-05 SE SE1550267A patent/SE1550267A1/sv not_active Application Discontinuation
  • 2015-03-09 DE DE112015000774.1T patent/DE112015000774T5/de not_active Ceased
  • 2015-03-09 WO PCT/SE2015/000013 patent/WO2015133957A1/en active Application Filing

Patent Citations (7)

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