JPH0112930B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine restart device that automatically restarts an engine that has been stopped when a vehicle is decelerating or idling.

A known engine restart device is one that shuts off the ignition circuit and fuel circuit during deceleration, stops the engine, and then automatically restarts the engine using a starter motor (Japanese Patent Publication No. 51-9085).

However, although this device reduces fuel consumption to some extent, since the engine is driven by a starter motor, it cannot ultimately be said to meet the goal of overall energy saving.

Therefore, the applicant has already proposed a device in which the deceleration energy of the vehicle is stored as the rotational energy of a flywheel for energy recovery, and this energy is used to restart the engine (Japanese Patent Application No. 55-5428). ).

However, in this engine restart device, the energy recovery mechanism and the transmission mechanism have the same structure, so even if a certain amount of rotational energy is stored in the recovery flywheel during deceleration, it is only necessary to restart the engine. Therefore, in order to restart the engine, the moment of inertia of the flywheel must be increased, resulting in an increase in the size of the flywheel.

The present invention aims to solve these conventional problems.

To this end, the present invention includes: an energy recovery flywheel that selectively interlocks with the drive shaft of the engine; an energy recovery means that connects a first clutch device to drive the flywheel when braking the vehicle; Means for cutting fuel to stop the engine during deceleration or idling, and means for connecting a second clutch device to start the engine using the recovered energy of the flywheel when releasing the clutch during deceleration or idling. The rotational speed ratio is set such that the energy recovery means accelerates the rotation of the engine drive shaft and transmits it to the flywheel, and the activation means decelerates the rotation of the flywheel and transmits it to the engine drive shaft.

Based on the above configuration, the flywheel is rotated at an increased speed during braking by the engine brake or other braking device, so that deceleration energy is efficiently stored in the flywheel. On the other hand, at startup, the rotation of the flywheel is decelerated and transmitted to the engine drive shaft, so that the necessary high torque is ensured according to the reduction ratio. Therefore, if the required starting torque is the same, the flywheel capacity can be reduced or the stored energy can be substantially increased.

Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, 1 is an engine body, 2 is a fan, 3 is a drive shaft driven by the engine via a belt 4, 5 is an energy recovery device including a flywheel that interlocks with the drive shaft 3, and 6 is a crank. A flywheel provided on the shaft, 7 a ring gear provided on the flywheel 6, 8 a drive shaft for transmitting the recovered energy of the energy recovery device 5, 9 provided at the tip of this drive shaft 8 and meshing with the gear 7. It's gear.

To explain in detail the energy recovery means provided in a part of the generator, as shown in Fig. 2,
Reference numeral 10 denotes a pulley that is interlocked with the engine via a belt 4, and this pulley 10 is connected to the drive shaft 3 via a clutch 11. A stator 13 of a generator is attached to the drive shaft 3, and an internal gear 14 is formed in a part of the stator 13. Note that the clutch 11 transmits the driving force from the pulley 10 to the stator 13, but cuts off the reverse transmission.

Recovery flywheel 16 and generator rotor 1
7 are directly connected by a shaft 18, and these are supported by bearings 19, 20 so as to be freely rotatable relative to the stator 13. This shaft 18 further includes a sun gear 21.
is locked with a key and meshes with the internal gear 14 via a planetary gear 22 to constitute a planetary gear mechanism as speed increasing means. Planetary gear 22
is rotatably provided on a disk 23 which is rotatably supported on the shaft 18. When an electromagnet 24 fixed to the housing as a first clutch device is energized, the disk 23 is attracted and becomes stationary. Therefore, when the rotation of the disk 23 is stopped during deceleration by a signal from a deceleration detection means (not shown), the rotation of the drive shaft 3 is increased and transmitted to the flywheel 16.

Since the disk 23 is open except during deceleration,
The flywheel 16 is free and is not restricted by the rotation of the stator 13, which rotates integrally with the drive shaft 3.

Next, to explain the engine starting means, a drive shaft 8 supported by a bearing 27 is attached to the end 18A of the shaft 18.
are inserted so that their ends are free to rotate relative to each other. An electromagnet 29 as a second clutch device is provided on the outer peripheral end 28A of the disk 28 that is press-fitted into the drive shaft 8.
When energized, the flywheel 16 is attracted, so the drive shaft 8 rotates in synchronization with the flywheel 16. When the engine is restarted, the recovered energy stored in the flywheel 16 is transmitted to the engine as engine starting force via the drive shaft 8, gears 9, 7 (see FIG. 1), and the like.

Next, the effect will be explained.

The planetary gear 22, which meshes with the internal gear 14 that rotates in the same manner as the crankshaft during acceleration or steady running of the vehicle, can freely revolve around the sun gear 21, and as a result, the sun gear 21 stands still and the rotational force of the engine is recovered as energy. The power is not transmitted to the flywheel 16, and only the stator 13 is rotated for power generation.

When decelerating, for example, when the brake pedal of the vehicle is detected, the electromagnet 24 is energized and the rotation of the disk 23 is stopped, so that the rotational force of the internal gear 14 is transferred to the energy recovery flywheel 16 via the sun gear 21. The rotation speed is increased and transmitted. Therefore, the kinetic energy of the vehicle during deceleration can be efficiently stored in the flywheel 16.

Here, in this embodiment, energy is recovered by increasing the angular velocity _ω of the flywheel ₁₆ using _the ^planetary gear mechanism. This is because increasing the angular velocity ω of the flywheel 16 rather than increasing the moment of inertia I of the flywheel 16 allows for a smaller flywheel and higher energy recovery efficiency.

When the flywheel 16 rotates at a higher speed than a predetermined speed during this deceleration, the ignition circuit and fuel circuit are cut off and combustion is interrupted. In this case, as long as the flywheel 16 is rotating at a high speed, the fuel cut is continued regardless of the rotation of the crankshaft, so that fuel can be effectively saved.

Note that even if the number of rotations of the crankshaft falls below a predetermined value, the flywheel 16 continues to rotate independently at high speed because the clutch 11 is interposed.

Next, when the accelerator is depressed from the deceleration state in which fuel is being cut off (or when the rotation of the recovery flywheel 16 has decreased to the set value), fuel supply and ignition are resumed. At this time, if the rotation of the crankshaft is extremely low or has stopped, the engine will normally stall; however, in the present invention, even if the vehicle stops in this case, the driving force of the energy recovery flywheel 16 is maintained. This allows the engine to automatically restart the engine.

In other words, when restarting after deceleration, the electromagnet 29
When energized, the disk 28 rotates coaxially with the recovery flywheel 16, and the energy stored during deceleration is transferred to the crankshaft via the drive shaft 8 and gears 7 and 6 with a large reduction ratio and high torque. introduce.

In this embodiment, as described above, when accumulating deceleration energy, the rotation speed is increased and recovered by the planetary gear mechanism, and when energy is released, the rotation speed is conversely decelerated and transmitted.Transmission mechanism: disk 28, coil 29, the drive shaft 8, gears 9, 7, etc. are provided, so that the energy of the recovery flywheel 16 can be efficiently applied to the engine as a high-torque driving force at the time of restart.

As a result, the energy recovery flywheel 16
It is possible to increase the stored energy by increasing the rotation of the engine, or it is possible to secure the high torque necessary for restarting even if the stored energy is kept at the same level as in the conventional example.

Therefore, even if the engine is stopped for a long time (up to an extremely low speed range) during deceleration, it is easy to restart the engine, and the weight of the restart device can also be reduced.

In addition, in this embodiment, fuel supply and ignition are stopped when the vehicle decelerates, and the starter motor does not need to be driven when restarting after deceleration, so it is possible to significantly save fuel and electricity. Of course.

As described above, the present invention includes: an energy recovery flywheel that selectively interlocks with an engine drive shaft; an energy recovery means that connects a first clutch device to drive the flywheel when braking a vehicle; Means for cutting fuel to stop the engine during deceleration or idling, and means for connecting a second clutch device to start the engine using the recovered energy of the flywheel when releasing the clutch during deceleration or idling. and the energy recovery means set the respective rotational speed ratios so that the rotation speed of the engine drive shaft is increased and transmitted to the flywheel, and the activation means is set such that the rotation of the flywheel is decelerated and transmitted to the engine drive shaft, When braking with the engine brake or other braking device, the flywheel rotates at an increased speed and can efficiently store deceleration energy, while when the engine starts, the rotation of the flywheel is decelerated and transmitted to the engine drive shaft. Therefore, the engine can be reliably started with high torque, and as a result, the restart device including the flywheel etc. can be made smaller and lighter in order to secure the required starting torque.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, and FIG. 2 is a sectional view of an energy recovery device that also constitutes an embodiment of the present invention. 1... Engine body, 3, 8... Drive shaft, 5...
... Energy recovery device, 14 ... Internal gear, 21 ... Sun gear, 22 ... Planetary gear, 24 ... Electromagnet (first electromagnetic clutch), 29
...Electromagnet (second electromagnetic clutch).

Claims (1)

[Claims] 1: an energy recovery flywheel that selectively interlocks with the drive shaft of the engine; an energy recovery means that connects a first clutch device to drive the flywheel when the vehicle is braking; means for stopping the engine by cutting the clutch; and means for connecting a second clutch device when released during deceleration or idling to start the engine using the energy recovered from the flywheel, An engine characterized in that the means sets a rotational speed ratio so that the rotation of the engine drive shaft is accelerated and transmitted to the flywheel, and the starting means is configured to reduce the rotation of the flywheel and transmit it to the engine drive shaft. Restart device.