JPH0138010B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides that a rotary flywheel for minimizing non-uniformity of rotational motion can be coupled and uncoupled to an internal combustion engine by means of a first clutch; The present invention relates to a method for operating a motor vehicle having a flywheel, which can be coupled and uncoupled to the wheels of the motor vehicle by means of a flywheel. Furthermore, the invention relates to a device implementing this method and a motor vehicle operated according to this method.

In operating states in which the drive engine does not drive the vehicle, such as during engine braking or coasting and no-load operation, and when the flywheel or flywheel that can be coupled to or uncoupled from the crankshaft is still rotating above a minimum rotational speed. A method has already been proposed for operating an internal combustion engine in a motor vehicle, in which the drive engine and the flywheel are decoupled and the engine is stopped when the vehicle is in use, in order to save fuel. The flywheel then continues to rotate as an energy storage device, and when the above-mentioned driving state has ended, the internal combustion engine can be started again by coupling the flywheel. This method is particularly well suited for relatively small vehicles in which road safety is not compromised by stopping the drive engine.

Furthermore, the vehicle drive system described in Japanese Patent Publication No. 61-50810 is a hybrid drive system, that is, a system that uses the power of a rotational energy source and the power of a flywheel as vehicle driving force, and the rotational speed of the flywheel and the rotational energy are This has the effect of making it possible to maintain the flywheel and the rotary energy source at maximum efficiency in various operating conditions and to reduce fuel consumption by being able to independently control the rotational speed of the source. It is. At this time, the vehicle is started and accelerated mainly by the power of the flywheel, and the power of the rotational energy source can be controlled to a low rotational speed sufficient to compensate for the energy loss of the vehicle. For this reason, a large inertial body is used in the flywheel.

In the case of this vehicle drive system, a flywheel with considerably high inertia or mass is used.
This flywheel can store enough kinetic energy to drive the entire vehicle, which means that only one flywheel can be coupled to a transmission to drive the vehicle; No internal combustion engine is required for this purpose.

The object of the invention is that a rotary flywheel for minimizing the non-uniformity of the rotary movement can be coupled and uncoupled to the internal combustion engine by a first clutch, and that the flywheel can be coupled to and uncoupled from the internal combustion engine by a second clutch. A motor vehicle with a flywheel that can be coupled and uncoupled to the wheels of a motor vehicle, even if the motor vehicle is a relatively large vehicle, with the lowest possible energy consumption, especially fuel consumption, without impairing road safety. It is to make it.

According to the present invention, this problem is solved as follows. That is, the flywheel is used to compensate for non-uniformities in the rotational motion of the internal combustion engine, and the flywheel is designed and selected so that it can be coupled to a transmission only if the flywheel is already coupled to the internal combustion engine; (a) disengaging the second clutch by means of the switching and control device in an operating state in which the vehicle is moving and the wheels are not driven by the internal combustion engine;
and (b) to keep the first clutch engaged and operate the internal combustion engine at a minimum speed; and (b) to ensure that the flywheel continues to rotate due to inertia when the motor vehicle is stopped for a short period of time. (c) restarting the internal combustion engine by disengaging the first and second clutches by the switching and control device and stopping the internal combustion engine; and restarting the internal combustion engine by engaging a second clutch and maintaining a second clutch in a disengaged state.

Hereinafter, differences from conventionally known technology and the device described in Japanese Patent Publication No. 61-50810 and the effects of the present invention will be described.

In the case of the invention, the flywheel or flywheel has a relatively low inertia or mass, which is not large enough to drive the vehicle. The flywheel of the invention is only selected to be used for compensation of non-uniformities in the rotational movement of internal combustion engines. Furthermore, in the case of the present invention, the flywheel can be coupled to the transmission only if the flywheel is already coupled to the internal combustion engine. That is, the flywheel of the present invention is never used by itself to drive a vehicle.

In the case of the device according to the invention, in the operating state in which the engine does not drive the moving vehicle, the transmission is decoupled from the internal combustion engine, the flywheel remaining coupled to the internal combustion engine, and e.g. Rotate further at the lowest rotational speed such as rotation speed. By doing so, the automobile can be operated more safely in such an operating state where the engine is not driving the vehicle while it is running. This means that at least auxiliary devices driven by the internal combustion engine that are necessary for the safety of driving a motor vehicle, such as steering assist devices, brake assist devices, generators, etc., are driven, and This is because these devices continue to function at least as long as the vehicle is moving. Situations in which it is not necessary to drive a running vehicle occur, for example, in coasting, throttle down, braking, and the like.

In the event of an operating condition that would cause the vehicle to stop,
As soon as the internal combustion engine reaches the lower speed limit value, the flywheel is also decoupled from the internal combustion engine, so that the internal combustion engine can be stopped and the flywheel is free to rotate further. The lower speed limit value at which the flywheel is uncoupled from the internal combustion engine is such that the kinetic energy stored by the flywheel at the moment of standstill is sufficient to start the internal combustion engine again for a given time. selected. The lower speed limit at which the flywheel is uncoupled from the internal combustion engine is, for example,
The minimum speed of the flywheel that makes it possible to start the internal combustion engine can be as large as 1000-1500 revolutions, for example, 500-1000 revolutions per minute. As soon as the minimum speed of the flywheel required for a reliable restart of the internal combustion engine is reached, e.g. for short restarts of the internal combustion engine or for electric motors with very low power consumption, By means of an additional small drive motor, the flywheel can once again be brought to relatively high rotational speeds. Another means for maintaining the kinetic energy in the flywheel high enough for starting the internal combustion engine is to maintain the kinetic energy at the flywheel high enough for starting the internal combustion engine at a lower speed limit, e.g. The flywheel, which is uncoupled from the motor vehicle, is held at a predetermined rotational speed by the electric drive motor during short stops of the motor vehicle.

In the present invention, the flywheel is not always disconnected from the transmission or from the internal combustion engine in order to preserve the maximum kinetic energy of the flywheel when decelerating or braking the vehicle. If it is desired to always disconnect the flywheel from both the transmission and the internal combustion engine, the internal combustion engine must be stopped. This is because, if a flywheel is not connected to compensate for the non-uniformity of the rotational movement of the internal combustion engine, the internal combustion engine will stop anyway. However, if the internal combustion engine stops, it is not possible to drive any auxiliary equipment, such as steering aids, braking aids, or generators, even though the vehicle is still moving at a high speed. There is a drawback. Naturally, therefore, driving safety can no longer be guaranteed.
This is because, for example, steering aids and brake aids are effectively switched off.

In order to avoid this situation, according to the invention, the internal combustion engine is coupled to the flywheel by a clutch, as long as the vehicle is in motion and the internal combustion engine is rotating above a predetermined lower speed limit value. is disconnected from the transmission and adjusted so that it continues to rotate at the lower rotational speed limit. As soon as the vehicle is stopped and therefore the internal combustion engine reaches a lower speed, the clutch is also disengaged from the flywheel internal combustion engine,
The internal combustion engine is stopped. The flywheel can therefore initially rotate further at a lower rotational speed limit, with the rotational speed gradually decreasing, for example due to friction in the bearing. In order to prevent the rotation of the flywheel uncoupled from the internal combustion engine from dropping below the minimum speed necessary to enable the internal combustion engine to be restarted by coupling the flywheel, the flywheel is As soon as this minimum rotational speed is reached, the flywheel is operated again, for example by a short restart of the internal combustion engine or by an additional small drive motor, such as an electric motor, which consumes very little power. The rotation speed is set to a high target. The time interval during which the internal combustion engine can be started again by the flywheel is such that the flywheel is absolutely necessary to be able to start the internal combustion engine reliably starting from the lower speed limit.
It depends on the time required to reach the aforementioned minimum rotational speed. This time, of course, depends on the quality of the flywheel bearing and the external geometry, which affects the air resistance. As the lower rotation speed limit value,
For example, 1000 revolutions per minute can be set, and the minimum revolution speed can be set, for example, to 500 revolutions per minute.

Such a method allows on the one hand a minimum fuel consumption, but on the other hand at the same time guarantees safe operation of the motor vehicle. This is because at least the devices necessary for driving safety and which are driven by the internal combustion engine, such as steering assist devices, brake assist devices, or generators, are driven, and these devices are operated at least when the vehicle is in motion. This is because it will continue to function as long as possible. In an automatic engine and with a negative pressure brake servo device, the braking force multiplication effect is maintained during operation. This is because the negative pressure source continues to be driven.

In order to start the internal combustion engine again if necessary after the end of an intentional short-term stop, such as stopping at a traffic light, this can be controlled, for example, by coupling the flywheel depending on the actuation of the accelerator pedal. In order to maintain the required kinetic energy of the flywheel at all times, it may be advantageous to: That is, in operating conditions when the motor vehicle is stationary and the flywheel is disconnected from the internal combustion engine and is to continue rotating, this flywheel is maintained by the electric motor at a predetermined rotational speed, the rotational speed being , sufficient to reliably start the engine when reconnected to the drive engine. The electric motor is then always supplied with a small current or with a train of short pulses, so that the flywheel can be maintained at an at least approximately constant rotational speed level. The demand for electrical energy required is therefore very low.

Another means of maintaining the kinetic energy of the flywheel for restarting the internal combustion engine at a predetermined minimum level and thus not practically weakening the existing energy management of the vehicle consists in the following. That is, in order to start the internal combustion engine and thereby bring it to a higher rotational speed, the flywheel is again coupled to the internal combustion engine so that when the specified limit rotational speed has fallen below, the flywheel is again brought to a higher rotational speed. accelerated to a speed level,
At that time, if the predetermined target rotation speed is reached,
The flywheel is cut off again and the internal combustion engine is stopped. The flywheel then continues to rotate freely and is actually only slightly slowed down by bearing friction and air resistance.

Another possibility of keeping the energy consumption as low as possible and preserving the kinetic energy of the flywheel required for restarting consists in the following. That is, when the drive engine stops and the flywheel reaches a predetermined lower rotational speed limit, the flywheel is brought to a higher rotational speed level via means such as a starter motor and reaches a predetermined target rotational speed. In the future, such measures will be cut off again. In this case, the starter can be a friction wheel starter, and the friction wheel of this starter is
It can be engaged with this flywheel in order to accelerate the flywheel to a target rotational speed.

In order to maintain the kinetic energy of the flywheel required for restarting the internal combustion engine by means of the electric motor, it is advantageous if the breakable flywheel forms the rotor of the electric motor or starter motor. The stator can then be fixed to the internal combustion engine or to the transmission housing. This feature according to the invention can be used in a device in which the flywheel is arranged rotatably concentrically and relative to the crankshaft of an internal combustion engine, and in which the bearing position is remote from the crankshaft. It can be used where a flywheel is provided so that it can rotate.

Furthermore, when the internal combustion engine is operating,
It is advantageous if the starting motor can be switched to generator operation. Such a device is simple and reliable. This is because the two auxiliary devices can be combined into one unit and no mechanical transmission means, such as friction wheels or V-belts, need to be provided between the motor or generator and the flywheel.

In this case, it is advantageous if the flywheel rotor integrated in the motor-generator has no windings and operates according to the known magnetoresistive method. It is also possible to configure the motor-generator according to the linear system or the guy system.

A first clutch is provided for coupling and discoupling the flywheel from the shaft of the internal combustion engine to minimize non-uniformity of rotational motion, and the flywheel is coupled to the internal combustion engine in the disengaged state of the first clutch. In an actuating device for a motor vehicle with a flywheel, which is rotatable relative to The flywheel is designed and selected so that it can be coupled to a transmission only when the vehicle is in motion, and has a second clutch located between the flywheel and the wheels of the vehicle. , the second clutch is automatically disengaged in an operating state in which the vehicle is not driven by the internal combustion engine, and the first clutch is automatically disengaged.
a switching and control device for keeping the clutches engaged and switching the internal combustion engine into no-load operation; a device for disengaging the second clutch and stopping the internal combustion engine; and a device for engaging the first clutch in response to operation of an accelerator pedal of the motor vehicle to start the internal combustion engine. and an electric drive for initially starting the internal combustion engine and accelerating the flywheel to a predetermined rated speed when the clutches are disengaged.

Embodiments of the present invention will be described below with reference to the drawings.

The figure shows a device 1 for carrying out a method for driving a motor vehicle by means of a drive engine 2 consisting of an internal combustion engine and a flywheel 3 connected behind this engine via a clutch 4, which clutch The servo device 5 is operated via an operating section not shown in
It can be connected to or disconnected from the crankshaft 6 of the internal combustion engine. A transmission input shaft 9 is connected to the transmission input shaft 9 via a further clutch 7, which is also switched by a servo device 8 via an actuator, which is not shown in detail in the figure.
The transmission 10 can be connected to and disconnected from the engine 2 via the .

The transmission 10 has drive shafts 11 and 12 for driving wheels 13 and 14.

Furthermore, the device has a starter 15 which can drive a starting wheel, for example a friction wheel 16, when a switch 17 is closed, for example via an ignition lock.

The following describes how the device of the present invention operates in response to common driving patterns of automobiles. First, when starting a car, the internal combustion engine 2 is started first, so both clutches 4 and 7 must be released when starting to drive. This is done via servo devices 5 and 8 which are controlled by a control device 18. A stopped flywheel 3 supported for rotation relative to the crankshaft 6
At this time, when current is supplied to the starter 15 via the switch 17 and the switching or control device 18,
A suitable starting rotation speed can be achieved through the friction ring 16,
As soon as the starting rotation speed is detected via the rotation speed measurement value generator 19, the clutch 4 is closed via the servo motor 5, the servo motor 5 receiving a corresponding command from the switching or control device 18. The flywheel 3 is connected to the crankshaft 6 of the internal combustion engine 2 and thus starts the internal combustion engine.

In the case of starting or normal driving motions in which the internal combustion engine drives the vehicle, the transmission clutch 7 is closed. For shifting, the clutch 7 is opened and closed in a known manner via a servo motor 8.

For example, in operating conditions in which the engine 2 does not drive the moving vehicle, such as during deceleration, braking, engine braking or coasting, each time the accelerator pedal 20 is released and the contact 21 is closed, the engine 2 is activated. The series is drive wheels 13, 14
and engine 2 via clutch 7,
In addition, it is switched off via the switching or control device 18. Depending on said operating state, this device:
Also, when both measured value generators 22 signal a rotational movement to the switching or control device 18, the servo motor 8
A control signal is applied to the clutch 7, and this control signal is applied to the clutch 7.
, thus disconnecting the engine from the drive wheels 13, 14 while the flywheel 3 remains connected to the engine. Depending on the position corresponding to the accelerator pedal, ie the position of the throttle valve in the carburetor engine, the engine 2 then rotates without load. Fuel consumption is then limited to a minimum value, but the functionality of auxiliary systems necessary for driving safety, such as brake servos, steering servos and generators, is maintained.

However, the above-mentioned disengagement of the clutch 7 while still maintaining full operational safety, and therefore the above-mentioned economical operation, can be carried out depending on the torque variation, i.e. the drive train in the drive train. This may take place as soon as no more torque is transmitted from the engine 2 to the drive wheels, or each time engine braking or coasting takes place, or each time there is a changeover from traction operation to engine braking or coasting.

Furthermore, the release of the clutch 7 can also be controlled as a function of changes in the underpressure occurring in the internal combustion engine, for example in the intake pipe. Typically this can be done if a rise is made from some previously existing negative pressure level. However, instead of relying on torque or pressure measuring devices, transmission disengagement could occur each time the accelerator pedal, or the element operated thereby, is returned from the position it once occupied in a "de-fueling" direction. good. This is effected, for example, by means of an entrainment switch 23 using a freewheel or the like. Such measures or measures ensure that this fuel-saving operating state occurs not only when the accelerator pedal is fully released, but also when part-load operation or engine braking or coasting has already begun. be done.

In the event of a short-term stop, such as a stop at a stoplight, for example, the rotational speed measurement value generator 22 signals a "stop" and, in addition, the drive train between the drive wheels 13, 14 and the internal combustion engine 2 The switching or control device 18 via the servo motor 8 is disengaged by the further clutch 4, so that the flywheel 3 can continue to rotate relative to the crankshaft 6 and the internal combustion engine 2 is then stopped. do. This takes place via a fuel supply or ignition current cutout 24 which is controlled by the switching or control device 18 .

To restart the engine during the desired continuation (restart), the flywheel 3 is again connected to the engine via the clutch 4, so that the engine is started. This is done by operating the servo motor 5 via the switching or control device 18 in dependence on the accelerator pedal actuation via the switch 21 or 23.

The flywheel 3 is maintained above a predetermined rotational speed level to ensure that the kinetic energy stored in the flywheel 3 is sufficient to ensure an unimpeded restart of the engine 2 in the event of a short stop. be done.

This means that the switching or control device 18 receives from the measured value generator 19 a value corresponding to a fall below a predetermined lower limit rotational speed and is notified by the measured value generator 25 that the engine has stopped. When the changeover or control device 18 closes the clutch 4 via the servo motor 5 and thus reconnects the engine 2 and the flywheel 3, the engine starts and thus starts. The flywheel is again accelerated to a high rotational speed, and when this high rotational speed is reached, a further control signal is generated by the measured value generator 19, so that it can be controlled via the switching or control device 18 and the servo motor 5. The clutch 4 is disengaged again, so that the freewheel rotates freely, and at the same time, via the device 24, the engine 2 is stopped again.

Another way of obtaining sufficient kinetic energy of the flywheel 3 to restart the engine is as follows. That is, when the measured value generator 19 informs the switching or control device of the lower limit speed, this device 18
The starter 15 is turned on via. The starter can, for example, be constructed as a Venjix starter and as soon as a corresponding rotational speed is detected via the measured value generator 19, the starter is switched off until the switching or control device 18 stops the starter. , the flywheel can be driven via the friction wheels 16. However, the starter 15 can also always maintain the flywheel 3 at a predetermined rotational speed after the lower limit rotational speed has been reached or as soon as the engine 2 has stopped. The starter 15 can then be switched off via the switching or control device 18 as a function of the accelerator pedal, actuation of the clutch 4 or rotational movement of the crankshaft 6. The initial starting of the internal combustion engine is performed by operating the switch 17.

A further constructional variant is shown in the figure, in which the flywheel 3 is replaced by an electric motor 26 for starting the drive engine 2.
is part of. The flywheel 3 is constructed as a rotor of an electric motor, and the stator 27 is arranged concentrically around the rotor. The initial starting of the drive engine 2 takes place via the switching or control device 18 by actuating the switch 17, the clutches 4, 7 being actuated via the associated servo motors 5, 8 as described above. has been done. Stator 2
7 is energized and reaches a predetermined rotational speed which is transferred via the measuring sensor 19 to the switching or control device 18, the clutch 4 is closed by the servo motor 5. The drive engine is then started. The power supply to the stator 27 is interrupted via the switching or control device 18 until it no longer signals to the switching or control device 18 via the measured value generator 19 that the predetermined limit speed has fallen below. , will remain as is. As a result of falling below a predetermined limit speed and of stopping the crankshaft 6 (which is signaled by the measured value generator 25), the stator 27 is energized, so that the flywheel 3
The kinetic energy of is maintained for restarting the drive engine 2, which can be done, for example, by actuating the accelerator pedal 20. The power supply can then take place steadily, but it can also take place in pulses or in such a way that the flywheel reaches a speed significantly higher than the required starting speed, until the lower limit speed is again reached. Allow it to rotate freely.

However, the electric motor 26 can also be switched into a generator depending on the minimum rotational speed of the drive engine, which minimum rotational speed is detected via the signal generator 25 and
and is transferred to the switching or control device 18. A switching or control device switches from generator to motor operation and vice versa.

The motor-generator 26 can operate according to the guy method or the linear method.

[Brief explanation of drawings]

The figure is a block diagram showing an apparatus for carrying out the method of the invention. 2... Engine, 3... Flywheel, 4, 7... Clutch, 13, 14... Drive wheel, 15, 26... Electric motor, 18, 22... Control section.

Claims (1)

Claims: 1. A rotary flywheel for minimizing the non-uniformity of the rotational motion can be coupled and uncoupled to the internal combustion engine by a first clutch, and said flywheel can be coupled and uncoupled to the internal combustion engine by a second clutch. A method for operating a motor vehicle having a flywheel, which can be coupled and uncoupled to the wheels of the motor vehicle, in which said flywheel is used for compensation of uneven rotational movements of an internal combustion engine, and the flywheel is already coupled to the internal combustion engine. The flywheel is designed and selected so that it can be coupled to a transmission and performs the following steps automatically only when: (a) the vehicle is running and the wheels are not driven by the internal combustion engine; disengaging the second clutch by means of a switching and control device;
and (b) to keep the first clutch engaged and operate the internal combustion engine at a minimum speed; and (b) to ensure that the flywheel continues to rotate due to inertia when the motor vehicle is stopped for a short period of time. (c) restarting the internal combustion engine by disengaging the first and second clutches by the switching and control device and stopping the internal combustion engine; A method for operating a motor vehicle having a flywheel, comprising the steps of: engaging a second clutch and maintaining a second clutch disengaged to restart the internal combustion engine. 2. During short stops of the motor vehicle, during the disengagement of the first and second clutches, the speed of the flywheel is increased to a value sufficient to ensure a corresponding start-up of the internal combustion engine for the reengagement of the first clutch. 2. A method as claimed in claim 1, further comprising the step of driving the flywheel by means of an electric drive in order to maintain the speed of the vehicle. 3. Said step (c) comprises the step of engaging the first clutch to start the internal combustion engine and accelerating the flywheel to a predetermined rated speed when the speed of the flywheel falls below a predetermined limit value; A method as claimed in claim 1, comprising the step of stopping the internal combustion engine when the engine speed is reached. 4. When the rotational speed of the flywheel falls below a predetermined limit value during a short-term stop of the motor vehicle, the rotational speed of the flywheel is increased by the starting motor, and when the rotational speed of the flywheel is increased to the predetermined rated speed, the starting 2. A method as claimed in claim 1, further comprising the step of disconnecting the electric motor. 5. The starting motor is a friction wheel starter, and the step of increasing the rotational speed of the flywheel includes coupling a friction wheel of the friction wheel starter to the flywheel to accelerate the flywheel to the rated speed. A method for operating an automobile according to claim 4. 6. When the rotational speed of the flywheel falls below a predetermined limit value during a short-term stoppage of the motor vehicle, the rotational speed of the flywheel is increased by the starting motor, and when the rotational speed of the flywheel is increased to the predetermined rated speed, the starting motor 2. A method of operating a motor vehicle as claimed in claim 1, further comprising the step of uncoupling the starter motor and switching the starter motor to generator operation during operation of the internal combustion engine. 7. The method of operating a motor vehicle according to claim 6, wherein the starter motor operates in a linear manner. 8. The method of operating an automobile according to claim 6, wherein the starting motor operates by a guy method. 9. A first clutch is provided for coupling and uncoupling the flywheel with the shaft of the internal combustion engine to minimize non-uniformity of rotational movement, and the flywheel is connected to the internal combustion engine in the disengaged state of the first clutch. An operating device for a motor vehicle with a flywheel, which is rotatable relative to The flywheel is designed and selected so that it can be coupled to a transmission only when the vehicle is running, and has a second clutch located between the flywheel and the wheels of the vehicle. A switching and control device is provided for automatically disengaging the second clutch and keeping the first clutch engaged and switching the internal combustion engine to no-load operation in operating conditions in which the vehicle is not being driven by the internal combustion engine. the switching and control device includes a device for disengaging the first and second clutches and stopping the internal combustion engine during an automatic short-term stop; and a device for starting the internal combustion engine. and a device for engaging the first clutch in response to operation of the vehicle's accelerator pedal, and for initially starting the internal combustion engine;
An operating device for a motor vehicle with a flywheel, characterized in that the device further comprises an electric drive for accelerating the flywheel to a predetermined rated speed when both clutches are disengaged. 10. An operating device for a motor vehicle according to claim 9, wherein the electric drive device operates according to a magnetoresistive method. 11. An operating system for a motor vehicle according to claim 9, wherein the electric drive operates according to a linear scheme. 12. The motor vehicle operating device according to claim 9, wherein the electric drive device operates according to the Guy method.