JPH037523B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a motor vehicle having an internal combustion engine.

In operating states in which the drive engine does not drive the vehicle, that is to say, for example during engine braking or coasting and no-load operation, and the flywheel or flywheel, which can be coupled or uncoupled to the crankshaft, still rotates at its minimum rotational speed. when the drive engine and flywheel are disconnected and the engine is stopped to save fuel.
Methods of operating internal combustion engines in automobiles have already been proposed. 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 invention, this problem is solved in a motor vehicle with an internal combustion engine, in which the internal combustion engine is provided with a flywheel for compensating for non-uniformity of the rotational movement, and the flywheel engages a first clutch on the crankshaft of the internal combustion engine. and is rotatably supported relative to the crankshaft, in a predetermined running state, such as when the internal combustion engine does not drive the running vehicle. Depending on the The first clutch is then disengaged, and the flywheel can be uncoupled, so that the flywheel can continue to rotate further and be recoupled when required by the internal combustion engine, and to start the internal combustion engine. , remains connected to the internal combustion engine until the internal combustion engine drives the motor vehicle, at which time the connection from the flywheel to the transmission is also severed via another clutch with the flywheel being uncoupled;
and the internal combustion engine is stopped or remains stopped, the disengageable flywheel has friction surfaces for both said clutches, and the flywheel functions both as the rotor of the generator and as the rotor of the starting motor. The common stator of the generator and the starting motor is arranged concentrically with the shaft of the rotor, and the stator/rotor assembly configured in this way is used as a starting motor. switchable from motor operation to generator operation, when the internal combustion engine is started at the start of travel, the stator/rotor assembly is switched to starting motor operation, the flywheel functioning as a rotor is brought to a predetermined rotational speed;
The problem is solved by configuring the internal combustion engine to be additionally connected.

The aforementioned flywheel or flywheel has a relatively small inertia or mass, which is not large enough to drive the vehicle; (i.e., the flywheel is not used to drive the vehicle by itself). It may also be possible to connect the flywheel to the transmission only if the flywheel is already connected to the internal combustion engine.

In the operating state, when the engine is not driving the moving vehicle, the transmission is decoupled from the internal combustion engine, with the flywheel remaining coupled to the internal combustion engine and at a minimum speed, e.g. no-load speed. It can be further rotated by the number. 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. That is, at least necessary for the safety of driving a car.
Auxiliary equipment driven by an internal combustion engine, e.g.
This is because devices such as the steering assist device, the brake assist device, and the generator are driven and continue to function at least as long as the vehicle is in motion. Conditions in which there is no need to drive a running vehicle include coasting, throttle down,
This occurs when using brakes, etc.

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 at which the flywheel is uncoupled from the internal combustion engine is selected such that the kinetic energy stored by the flywheel at the time of standstill is sufficient to start the internal combustion engine again at a predetermined time. can be done. The lower speed limit at which the flywheel is uncoupled from the internal combustion engine is e.g.
The minimum speed of the flywheel, which allows starting the internal combustion engine, can be as large as 1500 revolutions, for example, from 500 to 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. As a further means of maintaining the kinetic energy in the flywheel high enough for starting the internal combustion engine, the internal combustion engine can be operated at a lower speed limit, e.g. The flywheel, which is uncoupled from the flywheel, can be held at a predetermined rotational speed by an electric drive motor during short stops of the motor vehicle.

In order to preserve the maximum kinetic energy of the flywheel during deceleration or braking of the vehicle, it is possible to ensure that the flywheel is not always disconnected from the transmission or from the internal combustion engine. 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. This disadvantage arises. Thereby,
Naturally, driving safety can no longer be guaranteed. This is because, for example, steering aids and brake aids are effectively switched off.

To avoid this situation, the internal combustion engine, connected by the flywheel and clutch, is disconnected from the transmission as long as the vehicle is in motion and the internal combustion engine is rotating above the predetermined lower speed limit. It can be adjusted so that it is released and continues to rotate at the lower speed limit. As soon as the vehicle is stopped and the internal combustion engine reaches a lower speed, the flywheel is also uncoupled from the internal combustion engine and the internal combustion engine can be 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 that has been disconnected from the internal combustion engine from dropping below the minimum rotational speed that is absolutely necessary to be able to restart the internal combustion engine 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 reaches the aforementioned minimum speed which is absolutely necessary to be able to reliably start the internal combustion engine starting from the lower speed limit. It depends on the time needed to reach it. This time, of course, depends on the quality of the flywheel bearing and the external geometry, which affects the air resistance. For example, 1000 revolutions per minute can be set as the lower rotation speed limit value, and 500 revolutions per minute can be set as the minimum rotation speed.

Such a method makes possible, on the one hand, a minimum fuel consumption and, 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 system, the braking force multiplication effect can be maintained during operation. This is because it is continuously driven by the negative pressure generation source.

In order to restart the internal combustion engine 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, this flywheel is operated by the electric motor in operating conditions when the vehicle is stopped and the flywheel is disconnected from the internal combustion engine and is intended to continue rotating. maintained at a predetermined rotational speed by
This rotational speed is then sufficient to reliably start the drive engine upon reconnection. 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.

According to the invention, in order to maintain the kinetic energy of the flywheel necessary for restarting the internal combustion engine by means of the electric motor, the shatterable 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,
The starting motor can be switched to generator operation. Such a device is simple and reliable. Because 2
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. The motor-generator can also be constructed in a linear or guided manner.

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

The figure shows a device 1 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 is not shown in detail. The servo device 5 can be connected to or disconnected from the crankshaft 6 of the internal combustion engine via an operating section that is not connected to the servo device 5. A transmission 10 is coupled to and decoupled from the engine 2 via a 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. It is possible.

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

Furthermore, the device has a starting time 15, which starter 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 receiving flywheel 3 is connected to the crankshaft 6 of the internal combustion engine 2 and thus starts the internal combustion engine.

During start-up or normal driving, 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.

In the case of the motor vehicle according to the invention, the flywheel 3 is part of an electric motor 26 that starts the drive engine 2 . The flywheel 3 is configured as a rotor of an electric motor,
Moreover, the stator 27 is provided concentrically around the rotor. The initial start-up 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 as described above via the associated servo motors 5, 8. has been done. When the stator 27 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
It remains in this state until it is interrupted via the switching or control device 18 and no longer signals to the switching or control device 18 via the measured value generator 19 that the predetermined limit rotational speed has fallen below. By falling below a predetermined limit speed and by stopping the crankshaft 6 (which is signaled by the measured value generator 25), the stator 27 is energized and the flywheel 3 is thereby powered. The kinetic energy of is maintained for the restart of the drive engine 2, which means that
For example, this can be done by operating the accelerator pedal 20. At that time, power supply may be carried out steadily, but
It can also be done in pulses or in such a way that the flywheel reaches a rotational speed considerably higher than the required starting rotational speed and is allowed to rotate freely until the lower limit rotational speed is again reached.

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 the drawing]

FIG. 1 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, 1
8, 22...control unit.

Claims (1)

[Claims] 1. In an automobile having an internal combustion engine, the internal combustion engine is provided with a flywheel to compensate for non-uniformity of rotational motion, and the flywheel is connected to the crankshaft of the internal combustion engine via a first clutch. capable of being coupled or uncoupled and rotatably supported relative to the crankshaft, depending on a given driving condition, such as when the internal combustion engine does not drive the moving vehicle; The connection between the internal combustion engine and the flywheel is then interrupted via the first clutch when the flywheel is still rotating at a minimum speed, and the flywheel can be uncoupled, so that the flywheel can continue to rotate and be recoupled when required by the internal combustion engine, and remain connected to the internal combustion engine until it starts and drives the motor vehicle, at which time the uncoupled flywheel The connection from the flywheel to the transmission is then also interrupted via another clutch, and the internal combustion engine is stopped or remains stopped, and the uncoupled flywheel 3 has a friction surface for both said clutches. It has
The flywheel 3 is configured so that it can function both as the rotor of the generator and as the rotor of the starting motor 15, and the common stator of the generator and the starting motor 15 is arranged concentrically with the axis of the rotor. The stator/rotor assembly configured in this way can be switched from starting motor operation to generator operation, so that when the internal combustion engine is started at the start of running, the stator/rotor assembly is 1. A motor vehicle with an internal combustion engine, characterized in that the flywheel functioning as a rotor is switched to motor operation and is brought to a predetermined rotational speed, and then the internal combustion engine is additionally coupled. 2. The motor vehicle according to claim 1, wherein the rotor of the flywheel 3 has a non-wound shape. 3. The automobile according to claim 1 or 2, wherein the stator is attached to an internal combustion engine. 4. The automobile according to any one of claims 1 to 3, wherein the stator is attached to a casing of a transmission. 5. Motor vehicle according to claim 1, wherein during the operating state of the internal combustion engine 2, the starting motor 15 can be switched to generator operation. 6. Motor vehicle according to claim 1, wherein the motor 15, which can be switched to generator operation, in which the flywheel rotor 3 is integrated, operates in a magnetoresistive manner. 7. Any one of claims 1 to 6, wherein the motor 15 that can be switched to generator operation operates in a linear manner.
Vehicles listed in section. 8. A motor vehicle according to any one of claims 1 to 7, wherein the motor 15, which can be switched to generator operation, operates in a guy-type manner.