JPS58217743A - Engine torque variation suppression device - Google Patents

Abstract

PURPOSE:To suppress a rotational torque variation which will otherwise occure in a crank shaft for the elimination of vibration and gear meshing noises, by providing an engine with a timing detecting means, a field electric current control means, an engine speed detecting means and an adjusting means. CONSTITUTION:A timing detecting means 3 is adapted to detect a rotational position of 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. 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 engine speed. The field electric current thus energized causes the crank shaft to develop a reverse torque for suppressing a rotational torque variation. In this manner, a vibration, gear meshing noises and the like are effectively prevented.

Description

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

Generally, in an engine, the explosive force in the cylinder is converted into rotation of the crankshaft via the piston system, so while the crankshaft rotates, the explosion torque generated by the combustion gas pressure C is synchronized with this rotation. Torque fluctuations occur due to fluctuations and inertial torque fluctuations caused by the reciprocating inertia force of the piston system.

The rotational torque fluctuation that occurs on this crankshaft is
It causes vibrations, rattling noises, etc., and has various harmful effects.

Conventionally, as a device for suppressing fluctuations in the rotational torque of the crankshaft, as shown in Japanese Patent Laid-Open No. 6.5-7737, a seventh magnetic flux generating means that rotates integrally with the crankshaft of the engine, A technique has been proposed in which a second magnetic flux generation means on the fixed side is provided, and magnetic torque is generated in synchronization with rotational torque fluctuations generated in the crankshaft and in an opposite phase to the rotational torque fluctuations, thereby suppressing engine torque fluctuations. However, in the above proposed technology, the first
In addition, the second magnetic flux generating means must be formed separately, which poses a problem in terms of cost.

Therefore, in view of this, the present invention applies a field current to the field coil of the alternator when the rotational torque fluctuations occurring on the engine crankshaft increases, and generates a reverse torque on the crankshaft when the torque increases, thereby causing the engine crankshaft. The purpose is to suppress fluctuations in rotational torque generated in the shaft, use an existing alternator to suppress fluctuations in rotational torque, and effectively prevent vibrations, rattle noise, etc.

In other words, for example, in an in-line engine cylinder engine, engine explosions occur during two rotations of the crankshaft, so at low engine speeds such as when idling, the explosion torque fluctuations caused by the combustion gas pressure associated with this explosion occur. As a result, rotational torque fluctuations as shown in Fig. JA occur.

In contrast, in the present invention, a field current as shown in FIG. A load torque (reverse torque) as shown in C is generated, and the combination of this load torque C and rotational torque A results in a crankshaft composite torque as shown in the third diagram, and its fluctuation range becomes smaller. At that time, the 1MH41 torque fluctuation generated at the engine crankshaft is divided into the explosion torque fluctuation caused by the combustion gas pressure and the inertial torque fluctuation caused by the reciprocating inertia of the piston system. It is generated by the sum of However,
The above-mentioned explosive torque fluctuation and inertial torque fluctuation are out of phase, and the torque fluctuation due to the sum of the two changes at a certain rotation speed depending on the engine rotation speed.
The dominant one changes markedly.

That is, Fig. 3 and Fig. 7 show torque fluctuations in an in-line G-cylinder engine, and what is indicated by the dashed line I in Fig. 3 is the explosion torque fluctuation caused by the combustion gas pressure. What is shown by the thin solid line ■ is the inertia torque fluctuation caused by the reciprocating inertia force of the piston system, and the positive and negative fluctuations of both are out of phase by approximately 2θ degrees with respect to the crank angle. Furthermore, in Figure 7, which shows the amount of torque fluctuation, the explosive torque fluctuation (■) is approximately constant regardless of the engine speed, whereas the tangent value changes depending on the size of the load), and the inertial torque fluctuation (■) is It increases as the engine speed increases. Therefore, the torque fluctuation (1+n) due to the sum of the two shown by the thick solid line is equal to the constant rotation speed R (approximately /, 2
θ0 rpm) as the minimum value, and in the rotation range lower than this rotation speed R, the fluctuation due to the explosive torque fluctuation I is dominant,
In the high rotation range, fluctuations due to inertial torque fluctuations (2) become dominant, and the phase when the torque increases also occurs with a difference of approximately 20 degrees between the low rotation range and the high rotation range.

Regarding the above points, the present invention includes a timing detection means for detecting the rotational position of the crankshaft of the engine, and a first timing or timing that coincides with the torque increase of the explosion torque fluctuation caused by the combustion gas pressure in response to a signal from the timing detection means. A field current control means for supplying a field current to a field coil of an alternator at a second timing that coincides with an increase in torque due to inertial torque fluctuations caused by reciprocating inertia of the piston system; adjustment means for adjusting the field current control means so that the field current is applied at the second timing when the engine speed is lower than a set value, and the field current is applied at the first timing when the engine rotation speed is less than a set value. , provides an engine torque fluctuation suppressing device that generates reverse torque on the crankshaft when torque increases and suppresses rotational torque fluctuations generated on the engine crankshaft, and constantly suppresses torque fluctuations below an allowable level. It is something to do.

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 1a and a stator coil 1b, and a field coil i of the alternator 1 (1 is connected to a field current control means 2, and A timing detection means 3 is connected to the field current control means 2.The timing detection means 6 detects the rotational position of a crankshaft (not shown) in synchronization with the explosion of the engine. The current control means 2 receives a signal from the timing detection means 6 and applies a field current to the field coil 1a of the alternator 1 at a predetermined timing.

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.
is connected.

The crank angle sensor 7 constituting the timing detection 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 (when torque increases due to explosion torque fluctuation due to combustion gas pressure). It is something that
The detection signal of this crank angle sensor 7 is transmitted to a waveform shaping circuit 8.
is input and shaped into a square wave.

The signal from the waveform shaping circuit 8 is output to the monostable multivibrator 10 via the delay circuit 9 of the field current control means 2, and the monostable multivibrator 10 generates a predetermined pulse width corresponding to the time to apply the field current. This signal is amplified by one drive circuit 11 and applied to the field coil 1a of the alternator tough.

An adjustment means 12 is connected to the delay circuit 9 of the field current control means 2, and this adjustment means 12 controls the field current control means 2 when the engine speed is higher than a set value depending on the operating state (engine speed). A signal is output to the delay circuit 9 of.

When this delay circuit 9 receives a signal from the adjustment means 12, it converts the waveform shaping circuit 8 into a monostable multivibrator 10.
By operating to delay the signal output by about 2θ degrees (when the torque increases due to inertial torque fluctuation due to the inertial force of the piston system), the timing at which the field current is applied is delayed by a predetermined amount.

Therefore, the field current control means 2 includes a delay circuit 9
When the delay is not performed by the delay circuit 9, the field current is applied at the first timing that coincides with the torque increase of the explosion torque fluctuation caused by the combustion gas pressure.On the other hand, when the delay is performed by the delay circuit 9, the field current is applied at the first timing that coincides with the torque increase of the explosion torque fluctuation caused by the combustion gas pressure. A field current is applied at a second timing that coincides with an increase in torque due to inertial torque fluctuations caused by reciprocating inertial force.

In the adjustment means 12 for controlling the operation of the delay circuit 9, 16 is an ignition circuit, and 14 is an F that receives an ignition pulse from the ignition circuit 16 and converts the signal into a voltage value corresponding to the magnitude of the engine rotation speed. -V conversion circuit, 15 is a comparator that compares the signal of the F-V conversion circuit with a reference voltage and determines whether the engine speed is equal to or higher than the set value 2;
When the signal from the F-V conversion circuit 14 becomes equal to or higher than the reference value, the signal is output to the delay circuit 9 to adjust the field current control means 2 to the second timing, while the engine speed is less than the set value R. At this time, a field current is applied to the field coil la of the alternator 1 at a predetermined timing as a first timing.

The field current applied to the field coil 1d is applied at the first timing when the rotation is low and at the second timing when the rotation is high, and is applied when the torque increases due to rotational torque fluctuations occurring in the crankshaft. When this torque increases, the alternator 1 generates electricity to generate reverse torque on the crankshaft, thereby suppressing rotational torque fluctuations occurring on the crankshaft in synchronization with engine explosion. 〉 This example is shown in FIG. 2, and similarly to the previous example, the field current control means 2 applies the field current at the first timing when the engine speed is less than the set value R, and at the first timing when the engine speed is equal to or higher than the set value 2. It is adjusted to the second timing,
As the timing detection means 16, a device that detects the ignition pulse of the ignition circuit 16 color engine is used similarly to the adjustment means 12, and this ignition pulse is input to the waveform shaping circuit 8 and shaped into a rectangular wave. Through the switching circuit 18 of the current control means 17, the first or the first! It is output to delay circuits 19 and 20.

This switching circuit 18 receives a signal from the adjusting means 12, and closes a first contact 18a when the engine speed is less than a set value R, and closes a second contact 18b when the engine speed is equal to or higher than the set value R. . The first contact 18 of the switching port path 18
The first delay circuit 19 connected to a delays the timing of applying the field current by a predetermined amount from the ignition timing so that it becomes the first timing that matches the torque increase of the explosive torque fluctuation for low rotation. A second delay circuit 20 connected to the second contact 18b of the switching circuit 18 changes the timing of applying the field current from the ignition timing to a second timing that matches the torque increase due to inertial torque fluctuations for high rotations. It is delayed by a predetermined amount (approximately 20 degrees) from the time.

The signal from the first or second delay circuit 19.20 is outputted to the monostable multivibrator 7[]1, sets the time to apply the field current, is amplified by the drive circuit 11, and is sent to the field coil 1d of the alternator 1. Turn on electricity. The rest is the same as the previous example, and the same structures are denoted by the same reference numerals.

As explained above, according to the present invention, by providing the timing detection means, the field current control means, the engine rotation speed detection means, and the adjustment means, the crankshaft is always adjusted when the torque increases even if the engine rotation speed changes. It is possible to generate reverse torque on the engine crankshaft, effectively suppress rotational torque fluctuations generated on the engine crankshaft, improve problems such as vibration and tooth rattling noise, and use existing alternators. This method has the advantage of being advantageous in terms of cost.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention, FIG. 2 is a schematic configuration diagram showing the second embodiment, and FIG. 3 is an explanatory diagram showing the phase difference between explosive torque fluctuation and inertial torque fluctuation. FIG. 7 is an explanatory diagram showing the relationship between the amount of torque fluctuation and the engine speed, and FIGS.

Claims (1)

[Claims] (],) Timing detection means for detecting the rotational position of the crankshaft of the engine, and a first timing or reciprocation of the piston system that corresponds to the torque increase of the explosion torque fluctuation caused by the combustion gas pressure in response to the signal from the timing detection means. field current control means for applying a field current to the field coil of the alternator at a second timing that coincides with an increase in torque due to inertial torque fluctuations caused by inertial force; and adjustment means for adjusting the field current control means so as to apply the field current at the second timing and apply the field current at the first timing when the engine speed is less than a set value, and when the torque increases, A torque fluctuation suppressing device for an engine, characterized in that a reverse torque is generated on a crankshaft to suppress fluctuations in rotational torque generated on a crankshaft of an engine.