JPH0373740B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine torque fluctuation suppressing device.

Generally, in an engine, explosive force within a cylinder is converted into rotation of a crankshaft, so that during one rotation of the crankshaft, rotational torque fluctuations occur in the crankshaft in synchronization with the explosion. The rotational torque fluctuations generated in the crankshaft cause vibrations, rattling noises, and the like, and have various harmful effects.

Conventionally, as shown in Japanese Patent Application Laid-Open No. 1431/1983, a first magnetic flux generating means that rotates integrally with the crankshaft of the engine, and a fixed side have been used to suppress the rotational torque fluctuation of the crankshaft. the second of
A technique has been proposed for suppressing engine torque fluctuations by providing magnetic flux generating means and generating magnetic torque in synchronization with rotational torque fluctuations generated in the crankshaft and in an opposite phase to the rotational torque fluctuations. However, in the proposed technique, the first and second magnetic flux generating means must be separately formed in the conventional engine, which is disadvantageous in terms of cost.

In view of the above, the present invention includes a timing detection means for detecting when the torque increases due to rotational torque fluctuations occurring in the crankshaft in synchronization with the explosion of the engine, and a timing detection means for detecting when the torque increases due to rotational torque fluctuations occurring in the crankshaft in synchronization with the explosion of the engine. and a field current control means for applying a field current to the field coil of the engine, to generate a reverse torque on the crankshaft when the torque increases, and to suppress rotational torque fluctuations occurring on the crankshaft in synchronization with engine explosion, The present invention utilizes an existing alternator to suppress fluctuations in rotational torque and effectively prevent vibrations, rattling noises, etc., and also includes a battery condition detection means for detecting an overcharged state of the battery, and a signal received from the battery condition detection means. and an energizing means for energizing an electric load such as a hot wire heater when the battery is in an overcharged state, thereby preventing the battery from becoming overcharged and always maintaining a good state of battery charge. It is an object of the present invention to provide an engine torque fluctuation suppressing device.

Embodiments of the present invention will be described below with reference to the drawings. In Fig. 1, 1 is a field coil 1a.
and a stator coil 1b, the field coil 1 of the alternator 1
Field current control means 2 is connected to a,
Furthermore, timing detection means 3 is connected to this field current control means 2. The timing detecting means 3 detects when the torque increases due to rotational torque fluctuations occurring in the crankshaft (not shown) in synchronization with engine explosion, and the field current controlling means 2 receives the signal from the timing detecting means 3. In response, a field current is applied to the field coil 1a of the alternator 1 when the torque increases.

On the other hand, a battery 5, an electric load 6 such as a lamp, and a hot wire heater 6a (electric load) for removing fog from a rear window are connected to the stator coil 1b of the alternator 1 via a rectifier circuit 4.

The crank angle sensor 7 constituting the timing detecting means 3 outputs a detection signal when the piston of each cylinder is at a position delayed by a predetermined angle from the top dead center position. The signal is input to the waveform shaping circuit 8 and shaped into a rectangular wave.

The signal of the waveform shaping circuit 8 is output to the monostable multivibrator 9 of the field current control means 2, and is made into a signal having a predetermined pulse width corresponding to the time during which the field current is applied by this monostable multivibrator 9. is amplified by the drive circuit 10 and applied to the field coil 1a of the alternator 1 at a predetermined timing.

The field current applied to the field coil 1a is applied when the torque increases due to rotational torque fluctuations occurring at the crankshaft, and when this torque increases, the alternator 1 generates electricity, causing the crankshaft to generate a reverse torque. This is to suppress fluctuations in rotational torque that occur on the crankshaft in synchronization with engine explosion.

That is, for example, in a 4-stroke, 4-cylinder engine, explosions occur four times during two rotations of the crankshaft, so rotational torque fluctuations as shown in FIG. 2A occur.

On the other hand, the timing detection means 3 and the field current control means 2 apply a field current as shown in FIG. , By applying this field current, a load torque (reverse torque) as shown in Fig. 2C is generated, and by combining the load torque of C and the rotational torque of A, as shown in Fig. 2D, This results in a crankshaft composite torque, and its fluctuation range is suppressed to be small.

Reference numeral 11 denotes a battery status detection means for detecting an overcharged state of the battery 5, and 12 denotes an energizing means, which receives a signal from the battery status detecting means 11 and detects when the battery 5 is in an overcharged state. Then, the hot wire heater 6a is energized to increase the electrical load.

The battery state detecting means 11 detects the battery state of the battery 5.
The current change is detected from both ends of the resistor 13 connected in series with the current change, and this is amplified by the differential amplifier circuit 14, and the set value V _e is added to this amplified value V ₁ by the adder circuit 15. The signal V ₂ of the circuit 15 is output to a first comparator 16 . Also, the battery voltage V _S
is input to the second comparator 17.

In the first comparator 16, the output V ₂ of the adder circuit 15
is compared with a first reference value V _L , and this first reference value V _L is set according to the capacity of the battery 5, etc. so that the durability of the battery 5 will not be impaired due to overcharging under actual operating conditions. The first comparator 16 outputs a signal when the output V ₂ of the adder circuit 15 becomes larger than this value V _L .

The second comparator 17 converts the battery voltage V _S into a second
In comparison with the reference value V _B , this second reference value V _B is set to a value close to the reference voltage (12V) of the battery 5, and the battery voltage V _S becomes larger than this value V _B. At times, the second comparator 17 outputs a signal. In other words, the second comparator 17 outputs an output when the battery 5 is almost completely charged.

The outputs of the first comparator 16 and the second comparator 17 are
The signal is input to an AND circuit 18, and the output of this AND circuit 18 is output to the energizing means 12.

The energizing means 12 has a switch 12a for opening and closing energization to the hot wire heater 6a, and the AND
When the signal is output from the circuit 18, i.e.
Signals are output from both the first and second comparators 16 and 17, and even though the battery 5 is almost fully charged and a sufficient potential is present at the positive terminal, the amount of power generation is large and the battery 5 is exhausted. When the battery is in an overcharged state with a large amount of current flowing into the battery, the switch 12a is closed to energize the hot wire heater 6a, increasing the electrical load and increasing the discharge amount of the battery 5 to suppress overcharging. It is something.

Note that when no signal is output from the AND circuit 18, that is, in a normal charging state, the switch 12a of the hot wire heater 6a is manually opened and closed and used for the intended purpose.

The present invention is not limited to the structure of the above embodiment, but includes various modifications. That is, in the above embodiment, the hot wire heater 6a is used as the electrical load that is energized during overcharging, but other electrical loads such as an air conditioning fan that do not affect drivability even when activated can be used as appropriate. be.

In addition to the above-mentioned example, the timing detection means 3 may also be one that detects the ignition pulse of the engine from the ignition circuit. It is provided to apply a field current.

As explained above, according to the present invention, by providing the timing detection means and the field current control means, as well as the battery state detection means and the energization means, it is possible to generate reverse torque on the crankshaft when torque increases. , it is possible to suppress the rotational torque fluctuation that occurs in the crankshaft in synchronization with the engine explosion, and it is possible to improve harmful effects such as vibration and teeth rattling noise. Moreover, it can be done using an existing alternator. In addition to being advantageous in terms of cost, when the battery is in an overcharged state, the discharge of the battery is increased to prevent the occurrence of an overcharged state, and the durability of the battery due to overcharging is reduced. It is possible to suppress the decline.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention;
FIGS. 2A to 2D are explanatory diagrams showing the torque fluctuation suppressing effect. DESCRIPTION OF SYMBOLS 1... Alternator, 1a... Field coil, 1b... Stator coil, 2... Field current control means, 3... Timing detection means, 5...
...Battery, 6...Hot wire heater (electric load), 1
1...Battery state detection means, 12...Electrification means.

Claims (1)

[Claims] 1 Timing detection means for detecting when torque increases due to rotational torque fluctuations occurring in the crankshaft in synchronization with engine explosion, and applying a field current to a field coil of an alternator when torque increases upon receiving a signal from the timing detection means. field current control means; battery state detection means for detecting an overcharged state of the battery; and energization for receiving a signal from the battery state detection means and energizing an electric load such as a hot wire heater when the battery is in an overcharged state. 1. A torque fluctuation suppressing device for an engine, comprising means for generating a reverse torque on a crankshaft when torque increases, and suppressing rotational torque fluctuations generated on the crankshaft in synchronization with engine explosion.