Power train with hybrid power source

• US 20020177504A1
• Filed: 03/29/2002
• Published: 11/28/2002
• Est. Priority Date: 03/30/2001
• Status: Active Grant

• Current Assignee: LuK Lamellen und Kupplungsbau Beteiligungs KG
• Original Assignee: LuK Lamellen und Kupplungsbau Beteiligungs KG
• Inventors: Dilzer, Martin, Pels, Thomas, Reitz, Dierk
• Granted Patent: US 6,887,180 B2
• Time in Patent Office: Days
• US Class Current: 477/3
• CPC Class Codes: B60K 6/36 characterised by the transmission gearings
• CPC Class Codes: B60K 6/387 Actuated clutches, i.e. clutches engaged or disengaged by electric, hydraulic or mechanical actuating means
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60K 6/543 the transmission being a continuously variable transmission
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 2240/425 Temperature
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/10 including control of change-speed gearings
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 2510/087 Temperature
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2520/105 Longitudinal acceleration
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60Y 2400/428 Double clutch arrangements; Dual clutches
• CPC Class Codes: F02N 11/04 the motors being associated with current generators
• CPC Class Codes: F02N 11/0814 comprising means for controlling automatic idle-start-stop
• CPC Class Codes: F02N 2300/2002 using different starting modes, methods, or actuators depending on circumstances, e.g. engine temperature or component wear
• CPC Class Codes: F02N 5/04 : of inertia type
• CPC Class Codes: F16H 2061/0429 : by torque supply with a clutch in parallel torque path
• CPC Class Codes: F16H 2061/0433 : by torque supply with an electric motor
• CPC Class Codes: F16H 2200/0047 : the gear ratios comprising five forward speeds
• CPC Class Codes: F16H 2200/0052 : the gear ratios comprising six forward speeds
• CPC Class Codes: F16H 3/006 : power being selectively transmitted by either one of the parallel flow paths
• CPC Class Codes: F16H 3/126 : using an electric drive
• CPC Class Codes: F16H 37/0846 : CVT using endless flexible members
• CPC Class Codes: F16H 9/18 : only one flange of each pulley being adjustable
• CPC Class Codes: Y02T 10/40 : Engine management systems
• CPC Class Codes: Y02T 10/60 : Other road transportation technologies with climate change mitigation effect
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y10S 903/903 : having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/909 : Gearing
• CPC Class Codes: Y10S 903/914 : Actuated, e.g. engaged or disengaged by electrical, hydraulic or mechanical means
• CPC Class Codes: Y10S 903/918 : Continuously variable
• CPC Class Codes: Y10S 903/919 : Stepped shift
• CPC Class Codes: Y10S 903/945 : Characterized by control of gearing, e.g. control of transmission ratio
• CPC Class Codes: Y10S 903/946 : Characterized by control of driveline clutch
• CPC Class Codes: Y10S 903/947 : Characterized by control of braking, e.g. blending of regeneration, friction braking
• CPC Class Codes: Y10S 903/951 : Assembly or relative location of components

Abstract

The power train of a motor vehicle employs a hybrid drive including a combustion engine and an electrical machine. The transmission of the power train is shiftable into different gears in dependency upon the operating conditions of the vehicle. Such conditions include a traction condition when the vehicle is propelled by the engine and/or by the electrical machine, a coasting condition when the vehicle is being decelerated with attendant conversion of kinetic energy into electrical and/or rotational energy and storage of converted energy, a cold starting condition when the cold engine is started by the electrical machine, and a warm starting condition when the hot engine is started by the electrical machine and/or by at least one flywheel.

Claims

1. A power train for moving a vehicle during different stages of operation, comprising:

at least one internal combustion engine;

at least one electrical machine connectable with said engine and arranged to function as a motor and as a generator; and

at least one transmission interposed between said engine and at least one wheel of the vehicle and being shiftable into a plurality of gears in dependency upon the operating conditions of the vehicle, said conditions including;

a traction condition involving propulsion of the vehicle by at least one of said engine and said machine,

a coasting condition involving a deceleration of the vehicle which entails a conversion of kinetic energy developing as a result of deceleration of the vehicle into at least one of electrical and rotational energies and at least shortlasting storage of converted energy in at least one storage facility,

a cold starting condition involving a starting of cold engine by said machine, and

a warm starting condition involving a starting of still hot engine by one of said machine and a rotatory mass.

2. The power train of claim 1, wherein said engine has a rotary crankshaft and said transmission has a rotary input shaft, said rotatory mass including a fly-wheel connectable to and disconnectable from said shafts.

3. The power train of claim 2, wherein said flywheel is a rotor of said electrical machine.

4. The power train of claim 1, wherein said gears include higher and lower gears and said coasting condition further involves a shifting of said transmission from a lower gear into a higher gear, as seen from the at least one wheel of the vehicle.

5. The power train of claim 1, wherein said coasting condition includes a first mode of operating involving an acceleration of the rotatory mass in response to the application thereto of kinetic energy and a second mode of operation involving the utilization of said electrical machine for conversion of kinetic energy into electrical energy.

6. The power train of claim 5, wherein said modes of operation are selected as a function of different extents of deceleration of the vehicle.

7. The power train of claim 6, wherein the conversion of kinetic energy into electrical energy takes place as a result of relatively small deceleration of the vehicle and the conversion of kinetic energy into rotational energy takes place when the deceleration of the vehicle exceeds a predetermined threshold value.

8. The power train of claim 7, wherein said threshold value is adjustable.

9. The power train of claim 8, wherein said threshold value is between about 0.5 m/s² and 3 m/s².

10. The power train of claim 8, wherein said threshold value is between about 1 m/s² and 2 m/s².

11. The power train of claim 8, wherein said threshold value is adjustable by an operator of the vehicle in dependency upon desired deceleration.

12. The power train of claim 11, wherein said adjustable threshold value is dependent upon a signal derived from the mode of actuation of a brake pedal in the vehicle.

13. The power train of claim 12, wherein said signal is variable as a function of the magnitude of force e being applied to the brake ped al and said signal is generated by a pressure-responsive sensor associated with the brake pedal.

14. The power train of claim 1, further comprising a brake which is actuatable to decelerate the vehicle in addition to deceleration entailing said conversion of kinetic energy.

15. The power train of claim 14, wherein said conversion of kinetic energy into rotational energy takes place until the shifting of transmission from a lower gear into a higher gear, as seen from said at least one wheel, reaches a maximum value and is followed by conversion of remaining kinetic energy into electrical energy.

16. The power train of claim 1, wherein the conversion of kinetic energy into electrical energy takes place as a result of relatively small deceleration of the vehicle and the conversion of kinetic-energy into rotational energy takes place when the deceleration of the vehicle exceeds a predetermined threshold value, said threshold value being selected adaptively as a function of at least one operational parameter.

17. The power train of claim 1, wherein said rotatory mass is arranged to store rotational energy until the vehicle comes to a halt and said conditions of the vehicle further include at least partial conversion of stored rotational energy into electrical energy.

18. The power train of claim 17, wherein said at least partial conversion involves partial conversion into electrical energy and retention of an amount of stored rotational energy sufficient to start the engine, which is arrested during deceleration of the vehicle, as a result of connection of the rotatory mass with a rotary output element of the engine.

19. The power train of claim 1, further comprising means for automatically shifting said transmission so that the engine is operated with minimal consumption of fuel and any output increase initiated by the operator of the vehicle involves the utilization of said electrical machine.

20. The power train of claim 19, wherein the overall output of the power train including the output of said engine during operation with minimal consumption of fuel combined with the output of said electrical machine is reproducible within a range which is selectable by the operator of the vehicle.

21. The power train of claim 20, wherein said overall output is a function of at least one parameter which influences the output of said electrical machine and involves, in the event of influencing the output of said electrical machine, a departure from an optimal approximation to minimal fuel consumption by said engine to an extent corresponding to reduction of the output of said electrical machine by the at least one parameter.

22. The power train of claim 21, wherein said parameter is a characteristic output curve dependent upon at least one of RPM and temperature of said electrical machine, the condition of an energy source for said electrical machine, and the temperature of an electronic circuitry which controls said electrical machine and supplies electrical energy thereto.

23. The power train of claim 1, further comprising means for selectively connecting said electrical machine (a) with a rotary input shaft of said transmission and (b) with the at least one wheel by way of an output shaft of said transmission.

24. The power train of claim 23, wherein said electrical machine is connectable, in accordance with a characteristic curve denoting the RPM-dependent efficiency and having a maximum, with that one of said input and output shafts the RPM of which is nearer to the RPM denoted by said maximum of said curve.

25. The power train of claim 23, wherein said transmission is an automated transmission having a rotary input shaft and a rotary output shaft connected with the at least one wheel, and further comprising a starter clutch engageable to connect a rotary output element of said engine with said input shaft, a second clutch engageable to connect said output element and said electrical machine with said output shaft, and an engageable-disengageable third clutch interposed between said electrical machine and said output shaft, said electrical machine being connected with said output shaft in response to engagement of said third clutch and simultaneous disengagement of said second clutch and said electrical machine being connected with said input shaft in response to disengagement of said third clutch and simultaneous engagement of said starter clutch and said second clutch.

26. The power train of claim 25, wherein said electrical machine is arranged to synchronize the RPM of said input shaft with the RPM of said output shaft in response to shifting of said transmission into at least one of said gears.

27. The power train of claim 23, further comprising means for transmitting torque between a rotary output element of said engine and said electrical machine.

28. The power train of claim 1, further comprising means for arresting said engine not later than upon stoppage of the vehicle and means for automatically starting said engine in response to disengagement of a vehicle brake by the operator of the vehicle.

29. The power train of claim 1, further comprising an engageable and disengageable friction clutch between a rotary output element of said engine and a rotor of said electrical machine, said clutch being arranged to be engaged, following a stoppage of the engine subsequent to a short-lasting stoppage of the vehicle, to an extent just sufficient to ensure that the clutch can transmit starting torque from said electrical machine to said engine.

30. The power train of claim 29, wherein said friction clutch includes a rotary clutch plate having friction linings, pressure plates flanking said friction linings, and energy storing means arranged to frictionally engage said linings with said pressure plates, said energy storing means having a linear distance-to-force ratio.

31. The power train of claim 30, wherein said clutch is disengageable, upon starting of said engine in response to transmission of torque from said electrical machine, preparatory to shifting of said transmission into a selected gear and the vehicle is set in motion upon synchronization of said selected gear and initial frictional engagement between said friction linings and said pressure plates.

32. The power train of claim 1, further comprising means for coupling said electrical machine with said engine, said gears of said transmission including a gear in which a rotary output element of said engine is rotated by said electrical machine at a low speed while the vehicle is coasting.

33. The power train of claim 32, wherein said low speed is below about 1500 RPM.

34. The power train of claim 32, wherein said low speed is below about 1000 RPM.

35. The power train of claim 1, further comprising means for coupling said electrical machine with said engine, said machine being arranged to function as a generator to effect a reduction of kinetic energy while the vehicle is coasting until a deactivation of a coast shut-off of said engine, and further comprising an engageable and disengageable starter clutch interposed between a rotary output element of said engine and a rotary input shaft of said transmission, said clutch being disengaged upon deactivation of said coast shutoff and said engine being brought to a halt.

36. The power train of claim 1, further comprising means for lowering the compression ratio of said engine during starting thereof.

37. The power train of claim 1, wherein said electrical machine is arranged to generate heat and is adjacent a starter clutch which generates heat in response to slip, the heat which is being generated by said electrical machine - particularly while the output of said machine at least approximates a maximum value—

being dissipated into the surrounding atmosphere and said machine as well as said clutch being operated in dependency upon the extent of heat dissipation.

38. The power train of claim 37, further comprising means f or effecting an alternative regulation of at least one of said machine and said clutch as a function of combined heat output thereof.

39. The power train of claim 1, further comprising an engageable and disengageable clutch between said engine and said transmission, said clutch being engaged while the vehicle is coasting and said clutch being operated with slip to drive said engine during recuperation.

40. A method of operating a power train during different stages of operation of a motor vehicle which embodies the power train, the power train comprising at least one combustion engine, at least one electrical machine connectable with the engine and arranged to function as a motor and as a generator, and at least one transmission which is interposed between the engine and at least one wheel of the vehicle and is shiftable into a plurality of gears in dependency upon the operating conditions of the vehicle, comprising the steps of:

propelling the vehicle by at least one of the engine and the machine during traction operation of the vehicle;

decelerating the vehicle during coasting thereof with attendant conversion of kinetic energy developing as a result of deceleration of the vehicle into at least one of electrical and rotational energies and effecting an at least short-lasting storage of converted energy in at least one storage facility;

cold starting the vehicle including starting the engine by the electrical machine while the engine is cold; and

starting the engine, while still hot due to a previous operation, by at least one of the electrical machine and a rotatory mass.

41. The method of claim 40, wherein the rotatory mass is rotated by the electrical machine.

42. The method of claim 40, wherein said deceleration entails at least one of mechanical and electrical recuperations during deceleration of the vehicle in dependency upon at least one of the initial speed of the vehicle, deceleration gradient, load borne by the vehicle, and the extent to which a storage facility for electrical energy is charged.

43. A motor vehicle comprising a plurality of wheels and a hybrid power train for at least one of said wheels, said power train comprising an internal combustion engine, an electrical machine having a rotor connectable with said engine and arranged to operate as a motor and as a generator, and a transmission interposed between said engine and said at least one wheel and being shiftable into a plurality of gears in dependency upon operating conditions of the vehicle, said conditions including:

a traction condition involving a deceleration of the motor vehicle which entails a conversion of kinetic energy—

developing as a result of deceleration of the vehicle—

into at least one of electrical and rotational energies and at least short-lasting storage of converted energy in at least one storage facility,

a cold starting condition involving a starting of cold engine by said machine, and

a warm starting condition involving a starting of the engine, while still hot as a result of previous use, by at least one of said machine and a rotatory mass.