JPS58217742A - Engine torque variation suppression device - Google Patents

Abstract

PURPOSE:To suppress a rotational torque variation which will otherwise occure in a crank shft for the elimination of vibration and gear meshing noises, by providing an engine with a timing detecting means, a field electric current control means and a correcting means adapted to adjust the energizing timing of field electric current. CONSTITUTION:A timing detecting means 3 is adapted to detect the torque increasing timing of rotational torque variation occurring in a crank shaft in synchronization with the combustion of engine. A field electric current control means 2 energizes an alternator 1 with a field electric current upon the torque being increased. An adjusting means 12 to be connected with a delay circuit 9 delays an energizing timing of the field electric current by a predetermined magnitude in response to an operating condition. Upon the torque being increased, the crank shaft is caused to develop a reverse torque for suppressing a rotational torque variation occurring in the crank shaft in synchronization with the combustion of engine. In this manner, a vibration gear meshing noises and the like are effectively prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Misfire 1.11 relates to an engine torque fluctuation suppression device.

Generally, in an engine, explosive force within a cylinder is converted into rotation of a crankshaft, and therefore, while the crankshaft rotates, rotational torque fluctuations occur in the crankshaft in synchronization with the explosion. The rotational torque fluctuation generated in the crankshaft causes vibrations, rattling noises, etc., and has various harmful effects.

Conventionally, as a method for suppressing the rotational torque fluctuation of the crankshaft, as shown in Japanese Patent Application Laid-Open No. 36-7'737, a first magnetic flux generating means that rotates integrally with the crankshaft of the engine and , a technology has been proposed that suppresses engine torque fluctuations by providing a second magnetic flux generation means on the fixed side and generating magnetic torque in synchronization with the rotational torque fluctuations generated in the crankshaft and in the opposite phase to the rotational torque fluctuations. has been done.

However, in the above proposed technique, the first and second magnetic flux generating means must be separately formed in the conventional engine.
There is a problem 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. field current control means for supplying a field current to the field coil, and generates a reverse torque on the crankshaft when the torque increases, thereby suppressing rotational torque fluctuations generated on the crankshaft in synchronization with engine explosion, Suppresses rotational torque fluctuations by using existing alternators,
The purpose is to effectively prevent vibrations, rattling noises, etc.

At that time, the load torque generated by the field current applied to the field coil or the rotational torque generated by the engine crankshaft fluctuates according to changes in operating conditions such as engine speed or load, and the center of the fluctuation (
Since the peak value) changes, in the case where the field current is always applied at a constant timing, the torque fluctuation will be nfF due to the reduction of the fluctuation suppression effect in the specific operating range.
Regarding the above point, the present invention provides a correction means for correcting the field current control means and adjusting the timing of applying the field current according to the operating state. An object of the present invention is to provide an engine torque fluctuation suppressing device that always suppresses torque fluctuations to below an allowable level.

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

<Example/> In FIG. 1, 1 is an alternator equipped with a field coil 1d and a stator coil 1b, and a field current control means 2 is connected to the field coil 51cl of the alternator 1, and The timing detection means 6 is connected to the field current control means 21. The timing detecting means 6 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 6. As a result, when the torque increases, field coil 1 of alternator 1
On the other hand, the stator coil 1b of the alternator 1 is connected to a battery 5 and an electric load 6 such as a lamp through a rectifier circuit 4.
is connected.

The crank angle sensor 7 constituting the timing detection means 6 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 outputted to the monostable multivibrator 10 via the delay circuit 9 of the field current control means 2, and the monostable multivibrator 10 has a predetermined pulse width that corresponds to the time during which the field current is applied. This signal is amplified by the drive circuit 11 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 in the crankshaft, and when the torque increases, the alternator 1 generates electricity and reverses the rotational torque of the crank @31. It generates torque and suppresses rotational torque fluctuations that occur on the crankshaft in synchronization with engine explosion.

That is, for example, in a cycle-cycle engine, explosions occur y times during two revolutions of the crankshaft, so rotational torque fluctuations as shown in FIG. 2A occur.

On the other hand, the timing detection means 6 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 Figure 2 C is generated, and by combining the load torque of C and the rotating torque of A, the load torque as shown in Figure 4 is generated. , the crankshaft resultant torque, and its fluctuation range is suppressed to be small.

At this time, even if the field current is applied to the field coil 1d at the same timing, the load torque center of the load torque generated thereby changes depending on the engine rotation speed. In other words, as shown in Figure 3, the load torque (dotted chain line) at low rotations is small at the beginning and becomes large in the latter half, with the load center located at the rear. The load torque (solid line) during rotation has a large value even in the initial stage, and the load center shifts to the leading side compared to when the rotation is low.

Regarding this point, in this embodiment, when the application timing of the field current is set by matching the peak value of the rotational torque and the center of the load torque at low speeds, the timing of applying the field current is set by matching the peak value of the rotational torque with the center of the load torque at low speeds. In order to effectively suppress the rotational torque in combination with the rotational torque, the timing of applying the field current at high rotations is corrected to be delayed.

That is, the correction means 12 is connected to the delay circuit 9 of the field current control means 2, and this correction means 12 controls the field current when the engine speed is equal to or higher than a set value depending on the operating state (engine speed). Delay circuit 9 of means 2
A correction signal is output to delay the application timing of the field current to the field coil 1d by a predetermined amount.

In the correction means 12, 13 is an ignition circuit, 14 is an F-V conversion circuit which receives the ignition pulse from the ignition circuit 16 and converts the signal into a voltage value corresponding to the engine speed, and 15 is an ignition circuit. This is a comparator that compares the signal from the F-V conversion circuit with a reference voltage and determines whether the engine speed is above the set value.When the signal from the F-V conversion circuit 14 exceeds the reference value By outputting a correction signal and delaying the signal output from the waveform shaping circuit 8 to the monostable multivibrator 1o, the timing of applying the field current is delayed by a predetermined amount, and the peak value of the rotational torque and the center of the load torque are adjusted. It is a combination of

<Example! > This example is shown in FIG. 2, and similarly to the previous example, when the engine speed is higher than a set value, the timing of applying the field current is corrected to be delayed. Similarly, an ignition circuit 13 is used to detect the ignition pulse of the engine, and after this ignition pulse is input to the waveform shaping circuit 8 and shaped into a rectangular wave, it is passed through the switching circuit 18 of the field current control means 17. First or second delay circuit 19゜2
Output to 0.

This switching circuit 18 receives the signal from the correction means 12,
When the engine speed is less than the set value, the first contact 18a
, and when the value exceeds a set value, the second contact 18b is closed. The first delay circuit 19 connected to the first contact 18a of the switching circuit 18 delays the timing of applying the field current by a predetermined amount for low rotation from the ignition timing. The second delay circuit 20 connected to the ignition timing further delays the timing of applying the field current from the ignition timing for high rotations than for low rotations.

The signals from the first or second delay circuits 19 and 20 are output to the monostable multivibrator 10, set the time for applying field current, are amplified by the drive circuit 11, and energize the field coil 1a of the alternator 1. The rest is the same as the previous example, and the same structures are denoted by the same reference numerals.

<Embodiment 3> This example is shown in FIG. 7, and is intended to correct so that when the torque fluctuation increases beyond a set value, the application timing of the field current is advanced.

In other words, as shown in Fig. 5, the rotational torque fluctuation generated on the engine crankshaft has a peak value that becomes larger when the torque is high as shown by the solid line, compared to when the torque is low as shown by the dashed line. There is a slight shift toward the advance side, and the center of the increase in rotational torque shifts toward the advance side. In order to correct this, the application timing of the field current is advanced when the torque is high.

Field current control means 2 and timing detection means 6
The correction means 21 connected to the delay circuit 9 of the field current control means 2 has a vibration sensor 22 that detects torque fluctuation from engine vibration. The detection signal 22 passes through a low-pass filter 26 and is output to a full-wave rectifier circuit 24 as a signal containing only low-frequency components.
The full-wave rectified signal in step 4 is output to a comparator 25, which compares the output of the full-wave rectifier circuit 24 with a reference value, and when the high torque exceeds the reference value, the correction signal or the delay signal is output. It is output to the circuit 9, and by adjusting the timing of applying the field current by a predetermined amount (reducing the amount of delay), the center (peak timing) of the rotational torque and the load torque are aligned. The rest is the same as in Example 1, and the same structures are denoted by the same reference numerals.

In the third embodiment, the vibration sensor 22 detects when the torque increases, but it may also be detected from changes in the rotational angular velocity of the crankshaft using a crank angle sensor. Since there is a correlation, a detection signal from a throttle opening sensor that detects the filling amount or an electric load switch that indirectly detects the filling amount from the degree of load can be appropriately employed.

Further, the present invention is not limited to the structure of each of the above embodiments, but includes various modifications. In other words, in the above valley embodiment, the timing of applying the field current is controlled in stages. However, it is also possible to perform stepless correction according to changes in the operating state. Furthermore, the operating range for correcting the timing of applying the field current is not only based on the engine speed or torque fluctuations mentioned above, but also based on the detection of the rotational torque or load torque waveform, especially those that affect the peak timing. However, the torque fluctuation may be suppressed by combining the detection of various operating ranges.As described above, according to the present invention, by providing the timing detection means and the field current control means, It is possible to generate a reverse torque on the crankshaft when the torque increases, and to suppress the rotational torque fluctuations that occur on the crankshaft in synchronization with engine explosion, and it is possible to improve harmful effects such as vibration and teeth rattling noise. ,
This can be done by using an existing alternator, and has the advantage of being cost-effective.In addition, a correction means is provided to adjust the timing of applying field current according to the operating condition, and rotational torque and Since rotation 1-/ref fluctuation can be effectively suppressed by aligning the center with the load torque, rotation torque fluctuation can always be maintained within an allowable level and a stable suppressing effect can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram showing an uninvented embodiment, Fig. 2 is a schematic configuration diagram showing the second embodiment, and Fig. 3 is an explanation showing changes in load torque between high rotation and low rotation. Fig. 7 is a schematic configuration diagram showing Embodiment 3 of the present invention, Fig. 5 is an explanatory diagram showing changes in rotational torque between high torque and low torque, and Fig. z A-D shows torque fluctuation suppression. 0 which is an explanatory diagram showing the action

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 a field current applied to the field coil of the alternator when torque increases upon receiving a signal from the timing detection means. A field current control means for energizing, and a correction means for correcting the field current control means and adjusting the timing of applying the field current according to the operating condition are provided, and when the torque increases, a reverse torque is generated on the crankshaft, and the engine is controlled. An engine torque fluctuation suppressing device characterized by suppressing rotational torque fluctuations generated in a crankshaft in synchronization with an explosion.