Classifications

• • 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
  • F02B75/00—Other engines
  • F02B75/04—Engines with variable distances between pistons at top dead-centre positions and cylinder heads
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D15/00—Varying compression ratio
  • F02D15/02—Varying compression ratio by alteration or displacement of piston stroke
• • 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
  • F02B75/00—Other engines
  • F02B75/04—Engines with variable distances between pistons at top dead-centre positions and cylinder heads
  • F02B75/045—Engines with variable distances between pistons at top dead-centre positions and cylinder heads by means of a variable connecting rod length
• • 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
  • F02B75/00—Other engines
  • F02B75/04—Engines with variable distances between pistons at top dead-centre positions and cylinder heads
  • F02B75/048—Engines with variable distances between pistons at top dead-centre positions and cylinder heads by means of a variable crank stroke length
• • 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

Definitions

• the subject of the present invention is an electrohydraulic closed-loop control device of the control cylinder of a variable compression ratio engine comprising at least one hydraulic transfer valve and a control rack position sensor.
• the mechanical transmission device for variable compression ratio engine comprises a piston secured in its lower part of a transmission member cooperating on the one hand with a device rolling guide, and secondly with a toothed wheel secured to a connecting rod for transmitting the movement between said piston and said connecting rod.
• the mechanical transmission device for variable compression ratio engine comprises at least one cylinder in which moves a piston which is secured in its lower part, an organ transmission cooperating on the one hand by means of a small rack with a rolling guide device, and on the other hand by means of another rack of large dimension with a toothed wheel secured to a connecting rod.
• Said mechanical transmission device for variable compression ratio engine also comprises at least one control rack cooperating with the gear wheel, means for fixing the piston on the transmission member which provide a clamping preload, connecting means which make it possible to stiffen the teeth of the racks, and means for reinforcing and lightening the structure of the toothed wheel.
• control cylinder comprises a hydraulic fluid inlet under pressure designed to compensate for any leaks from said control cylinder, and to ensure a pre-charge pressure to increase the pressure. accuracy of keeping the setpoint in the vertical position of said control cylinder by reducing the effects of the compressibility of the oil while avoiding any cavitation phenomenon.
• a single electric motor can control the compression ratio of several cylinders via a camshaft or eccentric shaft.
• the adjustment of the initial compression ratio of each cylinder can be carried out by means of an independent adjustment device which can be a thread that is stopped in rotation.
• the electrohydraulic closed-loop control device of the control cylinder according to the invention makes it possible to solve a set of problems related to the control of the control cylinder (s) of the variable compression ratio engine:
• valves and their springs and the control rod involve providing a large diameter for the control cylinder, these components being housed at the periphery of the piston of said cylinder. This lowers the operating pressure and responsiveness of the control cylinder, increases the flow rates of hydraulic fluid between upper and lower chambers, and increases the bulk and weight of the entire control cylinder.
• the control of the compression ratio common to all the cylinders of the variable compression ratio engine involves transmission means between an electric motor for controlling the compression ratio and the control rods of each cylinder of the engine to variable compression ratio, as well as adjustment means specific to each cylinder. These bodies increase the size, weight and cost of the variable compression ratio engine.
• the electrohydraulic device for controlling the compression ratio of a variable compression ratio engine comprises at least one solenoid valve that can open or close at least one hydraulic fluid duct between the upper and lower chambers of a control cylinder at least one position sensor of a control rack, an angular position sensor of the engine crankshaft for adjusting the compression ratio and at least one computer.
• the electrohydraulic device for controlling the compression ratio of a variable compression ratio engine comprises a duct between the upper and lower chamber of the control jack which is arranged in the piston of said jack.
• the electrohydraulic device for controlling the compression ratio of a variable compression ratio engine comprises a duct between the upper and lower chamber of the control cylinder which is arranged in the crankcase of the engine with a variable compression ratio.
• the electrohydraulic device for controlling the compression ratio of a variable compression ratio engine according to the present invention comprises an upper chamber and a lower chamber of the control cylinder which are respectively supplied with pressurized hydraulic fluid from a hydraulic power unit by two feed-back check valves which open respectively into each of the two chambers and which allow the hydraulic fluid to enter the said chambers while prohibiting the exit.
• the electro-hydraulic device for controlling the compression ratio of a variable compression ratio engine according to the present invention cooperates with a knock detector in order to independently adjust the compression ratio of each cylinder of the engine according to its own physical characteristics.
• the electrohydraulic device for controlling the compression ratio of a variable compression ratio engine comprises a degassing solenoid valve enabling the upper chamber of the control cylinder to be connected to the engine oil sump.
• the electrohydraulic device for controlling the compression ratio of a variable compression ratio engine comprises a two-way solenoid valve having no non-return valve.
• FIG. 1 is a diagrammatic sectional view illustrating the main components and their positioning in the variable compression ratio motor of the electrohydraulic device according to the invention and according to a first embodiment which comprises two independent solenoid valves each placed on a circuit provided with a check valve, said solenoid valves cooperating with a position sensor of the control rack and a computer.
• FIG. 2 is a diagrammatic sectional view illustrating the main components and their positioning in the variable compression ratio motor of the electrohydraulic device according to the invention and according to a second variant embodiment which comprises a single solenoid valve comprising a two-way electrical slide inputs and two separate outputs defining two independent circuits each provided with a non-return valve, said solenoid valve cooperating with a position sensor of the control rack and a computer.
• a single solenoid valve comprising a two-way electrical slide inputs and two separate outputs defining two independent circuits each provided with a non-return valve, said solenoid valve cooperating with a position sensor of the control rack and a computer.
• FIG. 3 is a diagrammatic sectional view illustrating the main components and their positioning in the variable compression ratio motor of the electrohydraulic device according to the invention and according to a third variant embodiment which comprises a single solenoid valve cooperating with a position sensor of the control rack, an angular position sensor of the crankshaft of the variable compression ratio engine, and a calculator.
• FIGS. 1 to 3 show an electrohydraulic closed loop control device 80 of the control cylinder 8 of a variable compression ratio engine according to the present invention.
• the variable compression ratio engine comprises a mechanical transmission device 1 comprising in the lower part of the piston 2 a transmission member 3 integral with said piston and co-operating, of a part with a rolling guide device 4, and secondly with a gear wheel 5.
• the toothed wheel 5 cooperates with a connecting rod 6 connected to a crankshaft 9 in order to carry out the transmission of the movement between the piston 2 and said crankshaft 9.
• the toothed wheel 5 cooperates opposite the transmission member 3 with a control rack 7 whose vertical position relative to the cylinder block 100 is controlled by a control device 12 comprising the control cylinder 8, whose piston cylinder 13 is guided in a cylinder cylinder 112 arranged in the cylinder block 100.
• the control cylinder 8 comprises above an actuator cylinder 13 an upper chamber 121 and a lower chamber 122.
• the actuating cylinder 8 consists of an upper cylinder rod 10, a lower piston rod 16 cooperating with the jack piston 13.
• the upper cylinder rod 10 of the control cylinder 8 cooperates in its extension and in a sealed manner with a chamber 184 arranged in the cylinder head 300 of the variable compression ratio engine.
• the upper cylinder rod 10 may comprise in its inner part and at its center a check valve 185, the inlet of which is in communication with the chamber 184 arranged in the cylinder head 300 of the control cylinder 8, while the output of said booster check valve 185 is connected to a duct 187, formed in the jack piston 13 of the control jack 8 and opening into the lower chamber 122.
• the chamber 184 arranged in the cylinder head 300 is connected via a conduit to another booster check valve 188 housed in said cylinder head and communicating with the upper chamber 121 of the control cylinder 8.
• the upper chamber 121 and the lower chamber 122 of the control jack 8 are respectively fed with hydraulic fluid under pressure from a hydraulic unit by the two feed-back valves 185, 188 which open respectively into each of the two chambers 121, 122 and which allow the hydraulic fluid to enter the said rooms while prohibiting the exit.
• the transmission member 3 integral with the piston 2 is provided on one of its faces with a first large-sized rack 35 whose teeth 34 cooperate with those 51 of the toothed wheel 5.
• the transmission member 3 comprises, opposite the first rack 35, a second rack 37 whose teeth 38 of small dimensions cooperate with those of a roller 40 of the rolling guide device 4.
• crankcase 100 is secured to a support 41 comprising racks 46 ensuring the synchronization of the displacement of the roller 40 of the rolling guide device 4 with that of the piston 2.
• the electrohydraulic control device 80 of the compression ratio of the variable compression ratio engine comprises at least one solenoid valve 81 by control cylinder 8 that can open or close at least one conduit 83 of hydraulic fluid between the upper chamber 122 and lower 121 of said cylinder order 8.
• the electro-hydraulic control device 80 comprises in the cylinder head 300 and at each control cylinder 8 at least one position sensor 82 making it possible to determine, using at least one computer 84, the position of the control rack 7.
• the electrohydraulic device for controlling the compression ratio 80 of a variable compression ratio engine comprises a duct 83 between the upper chamber 121 and lower 122 of the control jack 8 which is arranged in the jack piston 13 of said control cylinder 8 .
• conduit 83 between the upper chamber 121 and lower 122 of the control cylinder 8 can be arranged in the crankcase 100 of the variable compression ratio engine.
• the electrohydraulic device 80 for controlling the compression ratio of a variable compression ratio engine comprises two solenoid valves 81 with an inlet and an outlet each of which can open or close the duct 83 connecting the upper chamber 121 to the lower chamber 122 of the cylinder. control 8, as illustrated in FIG.
• Each solenoid valve 81 comprises a non-return valve 85, 86 so that the non-return valve 85 of the first solenoid valve 81 prevents the hydraulic fluid from going from the upper chamber 121 to the lower chamber 122 of the control cylinder 8 but not the reverse, while the check valve 86 of the second solenoid valve 81 prohibits the hydraulic fluid to go from the lower chamber 122 to the upper chamber 121 of the control cylinder 8 but not vice versa.
• FIG. 2 illustrates a second variant of the electrohydraulic device 80 for controlling the compression ratio of a variable compression ratio engine which comprises a solenoid valve 81 comprising two inlets and two outlets which define two independent circuits, and a drawer three positions 87 allowing to connect the first input to the first output the second input being closed, either to connect the second input to the second output the first input being closed, or to close the two inputs.
• a solenoid valve 81 comprising two inlets and two outlets which define two independent circuits
• a drawer three positions 87 allowing to connect the first input to the first output the second input being closed, either to connect the second input to the second output the first input being closed, or to close the two inputs.
• the electrically operated solenoid valve 81 with slide 81 has two check valves 85, 86, the first check valve 85 prohibiting the hydraulic fluid from going from the upper chamber 121 to the lower chamber 121. of the control cylinder 8 but not vice versa, while the second non-return valve 86 prohibits the hydraulic fluid to go from the lower chamber 122 to the upper chamber 121 of the control cylinder 8 but not vice versa.
• FIG. 3 shows a third variant of the electrohydraulic device 80 for controlling the compression ratio of a variable compression ratio engine which consists of a single solenoid valve 81 able to open or close at least one hydraulic fluid conduit 83 between the upper chamber 121 and lower 122 of a control cylinder 8.
• the solenoid valve 81 is in two directions, has no check valve and can be controlled in a cyclic opening ratio.
• the two-way solenoid valve 81 cooperates with an angular position sensor 88 of the crankshaft 9 of the engine to adjust the compression ratio, in addition to the position sensor 82 of the control rack 7 and the computer 84.
• the two-way solenoid valve 81 comprises two parallel channels, one closed by a slow-speed, high-volume shutter device, the other closed by a fast-response, low-flow shutter device.
• the electrohydraulic device 80 for controlling the compression ratio of the variable compression ratio engine can cooperate with a knock detector, not shown, in order to independently adjust the compression ratio of each cylinder 110 of the engine as a function of its own physical characteristics.
• the electrohydraulic device 80 for controlling the compression ratio of a variable compression ratio engine comprises a degassing solenoid valve, not shown, for connecting the upper chamber 121 of the control cylinder 8 with the oil sump. of the motor.
• the opening of the electrovalve 81 for reducing the compression ratio is controlled by the calculator 84.
• control rack 7 Taking into account the forces applied to the control rack 7, and the ratchet effect produced by the non-return valve 86 placed on the same conduit 83 that the solenoid valve 81 kept open, said control rack 7 will move in one or more times until the position sensor 82 of said control rack 7 indicates to the computer 84 that the position of said control rack 7 corresponds to the desired compression ratio.
• the operation is identical when it comes to raising the compression ratio of the engine, but then involves the opening of the other solenoid valve 81 for increasing the compression ratio, cooperating with the nonreturn valve 85.
• the position sensor 82 of the control rack 7 will inform the computer 84 of the progressive drift of the position of the control rack 7.
• the computer 84 will open either the solenoid valve 81 for reducing the compression ratio or the solenoid valve 81 for increasing the compression rate. compression to restore the set position of said control rack 7.
• the second variant embodiment shown in FIG. 2 operates according to the same principle as that previously described in FIG. 1, with the difference that the functions of the separate solenoid valves 81 are in this case provided by a single solenoid valve 81 having an electrically operated slide 87 with two inputs and two outputs.
• a single solenoid valve 81 with two directions is provided, said solenoid valve being able to open and close fast enough to allow the control rack 7 to move only for a few degrees of angular displacement of the crankshaft 9.
• the computer 84 includes in its memory the angular position ranges of the crankshaft 9 during which the force applied to the control rack 7 is in the direction of increasing or reducing the compression when the conduit connecting the upper chamber 121 and lower 122 of the control cylinder 8 is open.
• the mapping of the direction of the force applied to the control rack 7 that integrates the computer 84 covers the entire range of speed and operating load of the variable compression ratio engine.
• the computer 84 controls the opening of the two-way solenoid valve 81 only when the angular position of the crankshaft 9 coincides with a force applied to the control rack 7 which goes in the direction of reducing the compression ratio.
• the computer 84 controls the opening of the two-way solenoid valve 81 only when the angular position of the crankshaft 9 coincides with a force applied to the rack command 7 which goes in the direction of increasing the compression ratio.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Output Control And Ontrol Of Special Type Engine (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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Publications (2)

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• 2007
  • 2007-04-16 FR FR0702732A patent/FR2914951B1/fr not_active Expired - Fee Related
• 2008
  • 2008-04-16 US US12/596,378 patent/US8875671B2/en not_active Expired - Fee Related
  • 2008-04-16 ES ES08805484T patent/ES2570764T3/es active Active
  • 2008-04-16 AU AU2008259733A patent/AU2008259733B2/en not_active Ceased
  • 2008-04-16 WO PCT/FR2008/000529 patent/WO2008148948A2/fr not_active Ceased
  • 2008-04-16 EP EP08805484.6A patent/EP2160507B1/de active Active
  • 2008-04-16 CN CN200880020059XA patent/CN101688473B/zh active Active
  • 2008-04-16 KR KR1020097023672A patent/KR101387772B1/ko active Active
  • 2008-04-16 CA CA2681616A patent/CA2681616C/en not_active Expired - Fee Related
  • 2008-04-16 JP JP2010503544A patent/JP5111602B2/ja active Active
• 2014
  • 2014-08-01 US US14/449,451 patent/US9376966B2/en active Active

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