JPS6231172B2 - - 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, etc.
It has various disadvantages.

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.

The present invention has been made in view of this point, and it generates reverse torque on the crankshaft when torque increases,
The rotational torque fluctuations generated in the crankshaft in synchronization with the engine explosion are suppressed, and the alternator is used as a generator to suppress the rotational torque fluctuations, effectively preventing vibrations, rattling noises, etc. It is an object of the present invention to provide an engine torque fluctuation suppressing device that prevents a battery from becoming over-discharged and maintains a good battery charging state at all times.

In order to achieve the above object, the present invention includes a timing detection means for detecting when the torque increases in rotational torque fluctuations occurring in the crankshaft in synchronization with engine explosion, and a torque increase upon receiving a signal from the timing detection means. field current control means for applying a field current to the field coil of the alternator; battery state detection means for detecting the discharge state of the battery; A correction means is provided for correcting at least one of the pulse width or the peak value of the field current in the direction of increasing the amount of power generation, and when the torque increases, a reverse torque is generated on the crankshaft, and in synchronization with the explosion of the engine, the correction means is provided on the crankshaft. It is characterized by suppressing rotational torque fluctuations that occur.

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

<Example 1> In FIG. 1, 1 is an alternator comprising a field coil 1a and a stator coil 1b, and the field coil 1a of the alternator 1
A field current control means 2 is connected to the field current control means 2, and a timing detection means 3 is connected to the 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 and an electric load 6 such as a lamp are connected to the stator coil 1b of the alternator 1 via a rectifier circuit 4.

The crank angle sensor 7 constituting the timing detection means 3 outputs a detection signal when the piston of each cylinder is at the top dead center position, and
The detection signal from the crank angle sensor 7 is input to a 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 revolutions of the crankshaft, so rotational torque fluctuations as shown in FIG. 3A 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. 3C is generated, and by combining the load torque of C and the rotating torque of A, as shown in FIG. 3D, This results in a crankshaft composite torque, and its fluctuation range is suppressed to be small.

Further, a correction means 11 is connected to the monostable multivibrator 9, and a battery state detection means 12 is connected to this correction means 11. The battery state detection means 12 detects the discharge state and overcharge state of the battery 5, and the correction means 11 receives the signal from the battery state detection means 12 and detects when the battery 5 is in the discharge state. The field current control means 2 is corrected in the direction of increasing the amount of power generated by the alternator 1, and in the direction of decreasing the amount of power generated by the alternator 1 when the battery 5 is in an overcharged state.

The battery state detecting means 12 detects the battery state of the battery 5.
A 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.The set value Ve is added to this amplified value V1 by the adder circuit 15. 15 signal V ₂ is output to first and second comparators 16 and 17. Also,
The battery voltage Vs is input to the third comparator 18.

In the first comparator 16, the output V ₂ of the adder circuit 15
is compared with a first reference value _V0 , and this first reference value _V0 is set according to the capacity of the battery 5, etc., so that the battery 5 does not become over-discharged (the battery goes up) under actual operating conditions. When the output V ₂ of the adder circuit 15 becomes lower than this value V ₀ , the first comparator 16 outputs the signal S ₁ . That is, when V ₀ and Ve are equal, there is an output S ₁ from the first comparator 16 in a discharge state in which the current i becomes negative and supplements the supply of power from the battery 5 to the electric load 6 . Note that V ₀ is appropriately set within the range of V ₀ ≦Ve.

In the second comparator 17, the output V ₂ of the adder circuit 15
is compared with a second reference value V _L , and this second reference value V _L is set according to the capacity of the battery 5, etc., so that the durability of the battery 5 is not impaired due to overcharging under actual operating conditions. The second comparator 17 outputs a signal when the output V ₂ of the adder circuit 15 becomes larger than this value V _L .

The third comparator 18 converts the battery voltage Vs into a third comparator.
Compared with the reference value V _B , this third reference value V _B is set to a value close to the reference voltage (12V) of the battery 5, and when the battery voltage Vs becomes larger than this value V _B A signal is output from the third comparator 18. In other words, the third comparator 18 outputs an output when the battery 5 is almost completely charged.

The outputs of the second comparator 17 and the third comparator 18 are
The signal is input to an AND circuit 19, and the output S ₂ of this AND circuit 19 is output together with the output S ₁ of the first comparator 16 to the switching circuit 20 of the correction means 11.

A first correction circuit 21 that outputs a correction signal that increases the pulse width is connected to the first contact 20a of the switching circuit 20.
A second correction circuit 22 that outputs a correction signal that reduces the pulse width is connected to the second contact 20b, and a third contact 20c is a neutral point.

The switching circuit 20 operates when the first comparator 16 outputs the signal _S1 , that is, when the battery 5
When is in a discharging state, the first contact 20a is closed and the correction signal from the first correction circuit 21 is input to the monostable multivibrator 9, and the pulse width by the monostable multivibrator 9 is corrected to increase the width. This increases the amount of power generated by the alternator 1 by lengthening the application time of the field current applied when the torque increases.

Further, the switching circuit 20 includes the AND circuit 1
When the signal S ₂ is output from 9, that is, the second
A signal is output from both the third comparators 17 and 18, 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 side is When in an overcharged state where a large amount of current flows, the second contact 20b is closed and the monostable multivibrator 9 is activated.
A correction signal from the second correction circuit 22 is inputted to the input circuit 22, and the pulse width of the monostable multivibrator 9 is corrected to reduce the field current application time, thereby reducing the amount of power generated by the alternator 1.

Note that the first comparator 16 and the AND circuit 19
When no signal is being output from the monostable multivibrator 9, that is, in a normal charging state, the switching circuit 20 maintains the pulse width at the third contact 20c at the value set by the monostable multivibrator 9.

<Example 2> In the previous example, the amount of power generated by the alternator 1 was corrected by increasing or decreasing the pulse width of the field current, but in this example, as shown in FIG. The power generation amount of the alternator 1 is corrected by increasing or decreasing the amount.

Crank angle sensor 7 of timing detection means 3
The detection signal is shaped into a rectangular wave by the waveform shaping circuit 8 and inputted to the monostable multivibrator 9 of the field current control means 2, and after being converted into a signal having a predetermined pulse width by the monostable multivibrator 9. , are input to the attenuation circuit 23.

The signal from this attenuation circuit 23 is amplified by an amplifier circuit 24 at an amplification degree corresponding to the discharge state of the battery 5, and this signal is further amplified by a drive circuit 10 and applied to the field coil 1a of the alternator 1 at a predetermined timing. It is.

An amplification degree correction circuit 25 of a correction means 26 is connected to the amplification circuit 24.
5 is connected to a battery state detection means 12 similar to the previous example.

When the battery 5 is in a discharging state and the signal _S1 from the first comparator 16 is being output, the amplification correction circuit 25 outputs a correction signal that increases the amplification of the amplifier circuit 24 and adjusts the field. The amount of power generated by the alternator 1 is increased by increasing the peak value of the current.

Also, if battery 5 is in an overcharged state, AND
When the signal S ₂ is output from the circuit 19,
The amplification degree correction circuit 25 outputs a correction signal that reduces the amplification degree of the amplification circuit 24 to reduce the peak value of the field current and reduce the amount of power generated by the alternator 1, so that the battery 5 can be charged normally. When in this state, amplification is performed at an intermediate amplification degree set in the amplification circuit 24.

Note that the same structures as in Example 1 are designated by the same reference numerals.

The present invention is not limited to the structures of the above embodiments, but includes various modifications. That is, in both of the above embodiments, the pulse width or peak value of the field current is corrected stepwise (three steps), but it may be corrected steplessly. Further, the first embodiment and the second embodiment may be combined to correct both the pulse width and the peak value.

Furthermore, in both of the above embodiments, the battery 5
Although the field current is corrected during discharging and overcharging, in practice, it is sufficient to correct the field current so as to increase the amount of power generated by the alternator 1 during discharging.

On the other hand, the timing detection means 3 may be one that detects the ignition pulse of the engine from the ignition circuit, in which case a delay circuit is provided to apply the field current at a time delayed by a predetermined amount from the ignition timing. It is provided so that

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 correction 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 tooth rattling noise, and moreover, it can be done by using an alternator as a generator. This technology has the advantage of being cost-effective, and at the same time, when the battery is in a discharged state, it suppresses fluctuations in rotational torque while increasing the amount of power generated and charging the battery, thereby preventing insufficient charging. This is something that can be prevented from occurring.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing Embodiment 1 of the present invention,
Figure 2 is a schematic configuration diagram showing the second embodiment, Figure 3A
-D 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, 11, 26...Correction means, 12...
Battery state detection means, 20... switching circuit, 25
...Amplification correction circuit.

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. a field current control means; a battery state detection means for detecting a discharge state of the battery; and a pulse of the field current in a direction to increase the amount of power generated by the alternator when the battery is in a discharge state in response to a signal from the battery state detection means. A correction means for correcting at least one of the width and the peak value is provided to generate a reverse torque on the crankshaft when the torque increases, thereby suppressing rotational torque fluctuations generated on the crankshaft in synchronization with engine explosion. An engine torque fluctuation suppression device characterized by: