Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W20/00—Control systems specially adapted for hybrid vehicles
  • B60W20/10—Controlling the power contribution of each of the prime movers to meet required power demand
  • B60W20/13—Controlling the power contribution of each of the prime movers to meet required power demand in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• • 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
  • B60K6/08—Prime-movers comprising combustion engines and mechanical or fluid energy storing means
  • B60K6/10—Prime-movers comprising combustion engines and mechanical or fluid energy storing means by means of a chargeable mechanical accumulator, e.g. flywheel
  • B60K6/105—Prime-movers comprising combustion engines and mechanical or fluid energy storing means by means of a chargeable mechanical accumulator, e.g. flywheel the accumulator being a flywheel
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W10/00—Conjoint control of vehicle sub-units of different type or different function
  • B60W10/04—Conjoint control of vehicle sub-units of different type or different function including control of propulsion units
  • B60W10/06—Conjoint control of vehicle sub-units of different type or different function including control of propulsion units including control of combustion engines
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W10/00—Conjoint control of vehicle sub-units of different type or different function
  • B60W10/10—Conjoint control of vehicle sub-units of different type or different function including control of change-speed gearings
  • B60W10/101—Infinitely variable gearings
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W20/00—Control systems specially adapted for hybrid vehicles
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
  • F16H61/66—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing specially adapted for continuously variable gearings
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W2710/00—Output or target parameters relating to a particular sub-units
  • B60W2710/06—Combustion engines, Gas turbines
  • B60W2710/0616—Position of fuel or air injector
• • 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

Definitions

• This invention relates to vehicular propulsion and more particularly, it concerns a method for propelling a wheel driven vehicle in which the operation of a prime mover or engine is coordinated with kinetic energy storage in a manner to maximize efficiency of the overall propulsion system.
• Hybrid power plants or drive line systens for inertial loads like those incurred in the operation of automobiles and other wheeled vehicles are well known.
• hybrid systems include a prime mover such as an internal combustion engine or other device for converting potential energy contained in a combustible fuel to mechanical power capable of being transmitted to the drive wheels of a vehicle, for example, a kinetic energy storage device such as a flywheel, and a mechanical power transmission capable of power transfer between either of the engine or flywheel and the inertial load represented by the drive wheels of vehicle.
• the energy storage device or flywheel is used to store for subsequent conversion to usable power, either or both excess energy developed by optimized operation of the prime mover or the kinetic energy of vehicular deceleration.
• the many diverse hybrid systems described in prior patents and other literature may be characterized generally as being in one of two classes at least in terms cf intended
• a relatively high technology flywheel or a large capacity energy storage device provides the primary source of mechanical power used to satisfy power demand by the load or at the driving wheels of a vehicle, for example, with engine or prime mover developed power and energy of vehicle deceleration being used primarily to charge the flywheel as needed to supply the demand for power.
• hybrid systems within this first class can result in a substantial savings of fuel needed for vehicle propulsion due to (a) operation of the fuel consuming prime mover or engine only at optimum specific fuel consumption, (b) engine or prime mover shut-down when the kinetic energy stored is adequate to propel the vehicle and above that necessary to restart the engine or prime mover, and (c) the storage and use of braking energy resulting from deceleration of the vehicular mass and which otherwise would be wasted as heat energy.
• a major deterrent to the use of such systems are the many problems incident to the incorporation of a high technology flywheel in the drive line system. High speed flywheels contribute losses to the transmission of kinetic energy to and from the flywheel due to required gearing and clutches and the like. Also, such flywheels require elaborate evacuated housings for the avoidance of windage losses. Thus, high technology flywheel systems and similar large capacity energy storage devices are vulnerable to efficiency losses in themselves which offset in substantial measure the efficiency gained by optimized operation of the engine or prime mover.
• the prime mover or engine is relied on primarily to supply the power demand of the vehicular load with excess energy resulting either from operation of the prime mover or vehicle decelera ⁇ tion being stored in a relatively low capacity storage device such as an automotive crank shaft flywheel enlarged for increased capacity and operated at speeds on the order of or slightly in excess of conventional internal combustion engine crank shaft speeds.
• Hybrid systems of this second class have the advantage of being easily accommodated by the geometry of existing drive lines and also may use state-of- the-art technology relative to continuously variable trans ⁇ missions needed to optimize both classes of hybrid systems.
• This latter class of hybrid systems is exemplified by U.K. Patent Application No. GB 2031822A published April 30, 1980 (corresponds to U.S. Patent Application Serial No. 023,398, filed March 23, 1979) and also described in an article entitled: "The Vadetec Inertial Drive Line" by S. Shih, E. G. Trackman and Y. Ke per, Society of Automotive Engineers, No. 800101, February 1980.
• the operational mode for the second class of hybrid system has involved optimized operation of the engine to supply power called for at the drive wheels, irrespective of how low that power may be.
• the kinetic energy of vehicle deceleration is stored in the flywheel and the engine turned off whenever the energy thus stored in the flywheel is adequate to satisfy the drive wheel load as well as to restart the engine.
• a hybrid system represented by a fuel consuming prime mover having a power output connected to a vehicular load in series through a clutch, a flywheel and a variable speed transmission is operated in a manner to avoid low thermal efficiencies in the fuel consuming prime mover without adding efficiency losses to the remainder of the system very simply by operating the prime mover, when operation thereof is required, at no less than a minimum level of developed power which will provide a relatively narrow range of. good thermal efficiencies, storing prime mover developed power, which is in excess of that needed to propel the vehicle, in the flywheel during such operation of the engine and controlling the power delivered to the vehicular load by varying the speed ratio of the transmission.
• the prime mover is decoupled from the flywheel and shut off to terminate fuel consumption when the flywheel reaches a predetermined level of speed.
• the stored kinetic energy is then transmitted as power to the load by controlled operation of the variable speed transmission.
• a primary object of the present invention is, therefore, to provide an improved method for propelling a wheel driven vehicle using a hybrid system of the identified second class by operating the fuel consuming prime mover of the system only as needed and when needed, only in excess of output power levels providing a narrowed range of good thermal efficiencies.
• FIG. 1 is a schematic diagram illustrating the components of a hybrid system used in the practice of the present invention
• Fig. 2 is a graph representing an engine performance map
• Fig. 3 is a graph like Fig. 2 but depicting engine operation in accordance with the present invention.
• Fig. 4 is a graph showing a curve resulting from plotting values of BSFC against developed horse power at minimum constant engine speed.
• a hybrid power system or drive line is shown to include a fuel consuming prime mover or engine 10 having a power output shaft 12 adapted to be releasably coupled by a clutch 14 to a flywheel 16 and the input shaft 18 of a variable speed transmission, preferabl a continuously variable transmission_..tCVT) unit 20.
• the output of the CVT unit is through a mode control unit to a final drive shaft 24 coupled for power transfer to a load represented by a drive wheel 26 of a land vehicle.
• the prime mover or engine 10 may be any one of several types of engines which operate to convert the potential energy in a combustible fuel to a mechanical power output in the shaft 12 and is schematically depicted in Fig. 1 as a piston engine having a crank shaft 28 of which the shaft 12 is a direct extension, a fuel supply 30 and a metering device 32, preferably a fuel injector, by which a controlled supply of fuel may be fed from the supply 30 to the engine 10.
• the clutch 14, CVT unit 20 and mode control unit are fully described in the aforementioned published
• the CVT unit is capable of transmitting power from the input shaft 18 to the output shaft in a range of continuously variable speed ratios.
• the mode control unit may be considered as gearing by which the system may be shifted between "forward”, “neutral”, and “reverse” modes of operation as well as to provide multiple fixed speed ratio outputs from the CVT unit 20.
• the clutch 14 is a friction clutch and is capable of actuation between full engagement and non-engagement.
• the flywheel 16 is a low technology flywheel and will vary in size depending on the size of the engine 10 as well as the size of the vehicle or other load to be driven by the system. The flywheel functions both as a crank shaft flywheel for the engine and as an energy storage device and may in practice be of a size on the order of magnitude the same as a conventional crank shaft flywheel that would be used with the engine 10.
• the direct connection of the flywheel to the input shaft 18 of the CVT unit is predicated primarily on the capability of the CVT unit 20 to attain an output/ input speed ratio of 0/1 or infinity. While such ratios are entirely consistant with CVT state-of-the-art, it is contemplated that a conventional friction clutch (not shown) may be used between the flywheel and the shaft 18 to allow use of a CVT unit with a finite range of speed ratios or one in which the range does not extend to an output/input rati of 0/1.
• System control is provided by a microprocessor or computer 34 which like the system disclosed in the afore- mentioned published British patent application, includes a plurality of system monitoring inputs, a series of driver inputs and a series of outputs or control functions.
• Monitore system functions include engine torque, engine speed, flywheel and CVT input speed, CVT output speed, mode control state, load torque and load speed.
• Driver inputs may include a main control 36, a direction control member 38, a power control such as an accelerator 40, and a brake pedal 42.
• Outputs from the microprocessor 34 include a fuel control for adjusting the fuel injector 32 from a position of complete shut-off of fuel supply to the engine 10, a clutch control by which the clutch 14 may be adjusted between conditions of full disengagement through partial engagement to full engagement, a CVT ratio control and a mode control for the unit 22.
• flywheel 16 is also the crank shaft flywheel of the engine 10
• power developing operation of the engine 10 can occur only when the clutch 14 is engaged.
• the flywheel is rotated directly with the engine crank shaft and the transfer of power at the CVT input shaft 18 to the wheel 26 is dependent on adjustment solely of the CVT unit 20 and mode control unit 22.
• fuel consuming operation of the engine 10 is terminated or shut off at all times when the clutch 14 is disengaged.
• the engine 10 may be started initially by turning on the main control 36 to energize an electric starter motor (not shown) drivably coupled with the flywheel 16. At this time, the flywheel is decoupled from the wheel 26 either by adjustment of the CVT unit to a zero output ratio or by decoupling a clutch (not shown) between the flywheel and the input of the CVT unit 20. With the mode control unit 22 adjusted to operate the drive line in a forward vehicle propelling direction, power developed by the engine 10 will be transmitte to the wheel 26 with appropriate control of the CVT unit 20 and of the fuel injector 32 in a manner to be described in more detail below.
• Fig. 2 of the drawings.
• varying levels of constant thermal efficiency represented by lines of constant brake specific fuel consumptio (BSFC) each labeled with numerical values of Lb/H.P./Hr units, are shown for varying values of engine torque (M-Kg) and engine speed (R.P.M.).
• M-Kg engine torque
• R.P.M. engine speed
• Optimized power developed by the engine is represented in Fig. 2 by a curve T..
• ideal operation of the engine 10 from the standpoint of gaining the least expensive developed power from the engine itself would require regulation of the fuel injector 32 to provide values of torque and engine speed on the curve
• a corollary to_operation of the engine 10 at varying power levels without corresponding changes in the speed at which the engine is operated and which is important to a full understanding of the present invention is that when power developed by the engine is more than that required at the wheel 26, regardless of wheel speed (assuming that the ratio range of the unit 20 is not exceeded) , the speed of the engine and of the engine power shaft 12 will increase at a rate determined by the power excess. Moreover, any such increasing of engine speed due to engine developed power exceeding that used at the wheel 26, will result in an acceleration of or an increase in the rotational speed of the flywheel 16. In this way, power developed by the engine 10, which is in excess of that needed for vehicle propulsion, may be stored as kinetic energy in the flywheel 16.
• Fig. 3 the efficiency map of Fig. 2 is partially reproduced to illustrate the method of operating the drive line or power system of Fig. 1 in accordance with the present invention.
• the ideal engine operating curve T. is again shown for the same values of engine torque and speed, as are the p r oints Pa and Pmax rep c resenting' illustrative values of developed power. Additionally in Fig. 3, however,
• a point of minimum acceptable developed power P m;j _ n is shown at the intersection of the curve T. and a line T of constant torque which, in the illustrated embodiment, is selected to coincide approximately with the line representing a BSFC of .60 Lb/H.P./Hr.
• the engine 10 is either shut off to a non-fuel-consuming mode or operated in a power developing mode and when operated in the latter mode, only at or above a selected minimum percentage of 0 thermal efficiency, for example, a BSFC of .60 Lb/H.P./Hr, or only in a manner to develop a minimum constant torque represented by the line T .
• a selected minimum percentage of 0 thermal efficiency for example, a BSFC of .60 Lb/H.P./Hr, or only in a manner to develop a minimum constant torque represented by the line T .
• the power requirement at the wheel 26, as determined by driving conditions and driver actuation of the -5 accelerator pedal 40 can and often will be less than the minimum power P . at which the engine 10 is permitted power developing operation.
• the speed ratio of the CVT unit 20 and the fuel injector 32 will be controlled by the microprocessor 34 to maintain engine operation at the 0 minimum acceptable thermal efficiency with the result that developed power in excess of that required at the wheel 26 will cause the engine 10 to increase in speed.
• the increased engine speed in turn, will increase the speed of the flywheel 16 so that the developed power in excess of power asked for 5 at the wheel 26, will be stored as kinetic energy in the flywheel 16.
• Power developing operation of the engine 10 may continue at constant torque or on the line T in Fig. 3 and, in the absence of increased demand for power at the wheel 0 26, will result in engine and flywheel speed increasing to a preprogrammed shut-off speed, for example, 3,000 R.P.M.
• the engine operating mode will be terminated, the clutch 14 disengaged and the speed ratio of the CVT unit 20 adjusted to transmit kinetic energy stored in the flywheel 16 as power to the drive wheel 26.
• the flywheel speed slows to a minimum engine starting speed of 1,000 R.P.M., for example, the engine 10 is restarted by engagement of the clutc 14 and the fuel injector 32 adjusted to develop power no less than a value represented by the point P ⁇ n in Fig. 3.
• the curve Smm. is the result of plotting values of thermal efficiencies in terms of BSFC against engine horse power where engine speed is maintained at the constant minimum speed or 1,000 R.P.M., for example.
• the point P . representing the minimum power at which the engine 10 is permitted power developing operation lies at the intersection of a line Fc of constant BSFC' (.60
• the engine is preferably operated on the ideal power line or that represented by the curve T. in Fig. 3. If at the instant of power demand engine speed is between 1,000 and 3,000 R.P.M., for example, at 2,500 R.P.M., engine operation on the curve T. is initiated by terminating power developing operation of the engine 10, disengaging the clutch 14 and drawing kinetic energy from the flywheel 16 for initial acceleration by appropriate adjustment of the CVT unit 20. When the flywheel slows to approximately 1,000 R.P.M. , the engine 10 is restarted and the fuel injector 32 adjusted to provide a minimum power of P . . Thereafter, the fuel injector 32 and CVT unit 20 are controlled to maintain engine operation on the ideal curve T..
• flywheel 16 may approximate the size of a conventional crank shaft flywheel, speed response of the engine 10 to full depression of the accelerator pedal 40 does not differ significantly from a conventional automotive engine.
• the flywheel 16 is used to store the kinetic energy of vehicle deceleration. To achieve this use of the flywheel 16, whenever the load at the wheel 22 nulls or becomes negative as commanded by either the accelera- tor 40 or brake 42, the clutch 14 is disengaged. If the brake 42 is depressed, the energy of vehicular momentum is absorbed in the flywheel with appropriate downshifting of the CVT unit 20 to increase flywheel speed.
• the energy previously stored in the flywheel 16 Upon a subsequent command for acceleration, the energy previously stored in the flywheel 16 will be fed as power to the wheel 26 until the speed of the flywheel 16 is reduced to the minimal starting speed in the absence of a sudden demand for more power as described. At that time, the clutch 14 will be re-engaged and the engine 10 started using the residual energy stored in the flywheel 16.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Transportation (AREA)
• General Engineering & Computer Science (AREA)
• Automation & Control Theory (AREA)
• Control Of Vehicle Engines Or Engines For Specific Uses (AREA)
• Arrangement Or Mounting Of Propulsion Units For Vehicles (AREA)
• Harvester Elements (AREA)
• Arrangement And Driving Of Transmission Devices (AREA)
• Hybrid Electric Vehicles (AREA)

Applications Claiming Priority (1)

Publications (2)

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ID=22154632

Family Applications (1)

Country Status (6)

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• 1980
  • 1980-10-31 WO PCT/US1980/001471 patent/WO1982001519A1/fr not_active Application Discontinuation
  • 1980-10-31 DE DE803050625A patent/DE3050625A1/de not_active Withdrawn
  • 1980-10-31 EP EP19810901393 patent/EP0063566A4/fr not_active Withdrawn
  • 1980-10-31 JP JP81501888A patent/JPS57501838A/ja active Pending
  • 1980-10-31 AU AU72234/81A patent/AU7223481A/en not_active Abandoned
  • 1980-10-31 GB GB8218742A patent/GB2097347B/en not_active Expired

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