JPH0424538B2 - - Google Patents

Description

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

In general, an engine converts explosive force within a cylinder into rotation of an output shaft and outputs rotational torque from the output shaft, so fluctuations in rotational torque inevitably occur in synchronization with the explosion. Such fluctuations in the rotational torque of the output shaft become a factor that causes vibrations in the engine, rattle noise in the transmission, and the like.

Conventionally, various devices have been proposed for suppressing fluctuations in the rotational torque of the output shaft.

In Japanese Patent Application No. 57-68315, the present applicant has developed a system that detects the torque increase of the output shaft torque fluctuation and applies a field current to the field coil of the alternator when the torque increases. We have proposed an engine torque fluctuation suppressing device that generates a reverse torque and suppresses rotational torque fluctuations generated at the output shaft by this reverse torque.

By the way, in the above-mentioned torque fluctuation suppressing device, if the field current is constantly applied at a certain timing corresponding to the increase in torque, when the electric load such as a lamp increases, the amount of power generated by the alternator will be insufficient, which will put a burden on the battery. This causes the problem that was previously mentioned when the battery becomes prematurely damaged.

The present invention is basically based on the above-mentioned technical idea, and has been made to solve the above-mentioned problems.The present invention is basically based on the above-mentioned technical idea, and has been made in order to solve the above-mentioned problem. Focusing on the fact that the delayed phase in fluctuations can be obtained at the peak of the rotational angular velocity of the following output shaft, under normal conditions when the battery is not in a discharge state, reverse torque is generated at the peak of the rotational torque fluctuation to generate rotation. While effectively suppressing torque fluctuations, when the battery is in a discharged state, the field current is applied to the field coil at the peak of the rotational angular velocity, which places emphasis on the amount of power generated by the alternator and provides the maximum amount of power generated. An object of the present invention is to provide an engine torque fluctuation suppressing device that can quickly eliminate a battery discharge state.

That is, in the present invention, the first timing detects the torque increase of the rotational torque fluctuation generated in the output shaft in synchronization with the explosion of the engine, and generates the first timing signal at the timing when the rotational torque almost reaches its peak. A second timing generating means generates a second timing signal at a timing when the rotational angular velocity almost reaches its peak, and a battery state detecting means detects a discharge state of the battery, so that when the battery is not in a discharge state, , the field current is applied to the field coil of the alternator at the first timing, and when the battery is in the discharge state, the field current is applied at the second timing, and when the battery is in the discharge state, the rotation of the output shaft is The timing at which the field current is applied is corrected so that the amount of power generated by the alternator can be increased to coincide with the peak of the angular velocity, thereby effectively preventing battery build-up.

Hereinafter, the present invention will be described in more detail with reference to the illustrated embodiments.

In FIG. 1, reference numeral 1 denotes an alternator equipped with a field coil 2 and a stator coil 3. The field coil 2 is attached to a rotor (not shown) that is driven by a belt by a crankshaft (not shown), and a driver circuit. When a field current is applied by 4, an induced current is generated in a stator coil 3 fixed to a housing (not shown), and this induced current is converted to direct current by a rectifier circuit 5.
Necessary power is supplied to an electric load 6 connected to the output side of the rectifier circuit 5.

On the other hand, in FIG. 1, 7 is a crank angle sensor that outputs a spike-like pulse at the timing when the piston of each cylinder of the engine reaches the top dead center position;
8 is a first waveform shaping circuit that shapes the spike-like pulse output from the crank angle sensor 7 into a rectangular wave, and this first waveform shaping circuit 8 converts the output pulse into a first timing signal P ₁ (second (see Figure E) is applied to the first switching contact 9a of the switching circuit 9. These crank angle sensor 7 and first waveform shaping circuit 8 constitute a first timing signal generating means.

Further, 10 is a delay circuit that delays the spike-like pulse of the crank angle sensor 7 by a preset delay time τ, and 11 is a waveform of the spike-like pulse delayed by the delay time τ by the delay circuit 10 into a rectangular wave. This second waveform shaping circuit 11 uses the output pulse as a second timing signal P ₂ (see FIG. 2) and sends it to the switching circuit 9.
is applied to the second switching contact 9b. Above delay circuit 1
0. The second waveform shaping circuit 11 and the crank angle sensor 7 constitute a second timing signal generating means.

The switching circuit 9 turns on the first switching contact 9a when the switching signal S is not applied, depending on the presence or absence of the switching signal S output by the battery state detection means 12, which will be described in detail below, and switches the switch. When the signal S is applied, the monostable multivibrator 13, which is a switching circuit that turns off the first switching contact 9a and turns on the second switching contact 9b, and which is connected to the common contact 9c of this switching circuit 9, is switched to the first switching circuit. Operated by timing signal _P1 or second timing signal _P2 ,
The monostable multivibrator 13 outputs first and second drive signals Q 1 _and Q ₂ having predetermined time widths to the driver circuit 4 according to the first and second timing signals P ₁ and P ₂ .

Next, the battery state detection means 12 will be explained.

This battery state detection means 12 is for detecting the discharge state of the battery 14 connected in parallel with the electric load 6 to the output side of the rectifier circuit 5 of the alternator 1.
A low resistor 15 connected in series with the positive electrode side of 4 and this resistor 15
The voltage V ₂ ( _{V 2}
=V ₁ +V _e ) as an inverting input, and a comparator 18 that compares the voltage V ₂ with a reference value V ₀ set in advance as a non-inverting input.

The above reference value V ₀ is set to a value that is equal to or suitably lower than the above added value V _e in order to determine whether or not the battery 14 is in a discharge state in the actual operating state according to the capacity of the battery 14, etc. It is something that
When the voltage V ₂ becomes equal to or less than the reference value V ₀ , the comparator 18 outputs a switching signal S to switch the switching circuit 9 from the first switching contact 9a to the second switching contact 9b. In other words, the state where V ₀ ≧ V ₂ means a discharge state in which the current i flowing through the resistor 15 is negative and the electric load 6 is supplemented with electric power from the battery 14. , is configured to output a switching signal S when this discharge state is detected.

Next, the operation of the torque fluctuation suppressing device having the above configuration will be explained.

() When the battery 14 is not in a discharge state When the battery 14 is not in a discharge state, that is, when the amount of power generated by the alternator 1 is greater than the power consumption of the electric load 6, the battery state detection means 1
There is no output of the second output, and the switching circuit 9 is connected to the first output as shown in the figure.
The switching contact 9a is turned on.

Therefore, when the piston of each cylinder reaches the top dead center, the crank angle sensor 7 outputs a spike-like pulse, and the first waveform circuit 8 outputs the first timing signal _P1 , this first timing signal
P ₁ is connected via the first switching contact 9a of the switching circuit 9,
The signal is applied to the monostable multivibrator 13, and the monostable multivibrator 13 outputs the first drive signal _Q1 to the driver circuit 4 at the timing of the rise of the first timing signal _P1 , and the driver circuit 4 receives the first drive signal Q1. ₁ , a field current F1 is applied to the field coil ₂ of the alternator 1, as shown in FIG.

This field current F ₁ is applied to the field coil 2 during the peak of the rotational torque T of the crankshaft, that is, for an appropriate time interval before and after the peak of the rotational torque T, and the field current F ₁ is applied. Then, an electromagnetic force acts on the field coil 2 (therefore, the rotor) that prevents it from rotating, in other words, the alternator 1
A rotational torque in the opposite direction is generated, and this rotational torque in the opposite direction acts to offset the peak of the rotational torque T of the crankshaft, thereby effectively suppressing an increase in the rotational torque T.

() When the battery 14 is in a discharging state, when the battery 14 is in a discharging state, the battery state detection means 12 detects this and outputs a switching signal S to the switching circuit 9. The switching circuit 9 has a first switching contact 9
a to the second switching contact 9b.

Therefore, in this case, the delay circuit 10 outputs the first timing signal P ₁ by the delay time τ.
The second timing signal P ₂ delayed by
The signal is applied from the waveform shaping circuit 11 to the monostable multivibrator 13 via the second switching contact 9b.

The monostable multivibrator 13 activates the second timing signal _P2 at the rising edge of the second timing signal P2.
The drive signal _Q2 is output to the driver circuit 4, and the second
As shown in FIG. 2, the driver circuit 4 applies a second field current F ₂ to the field coil 2 of the alternator 1.

This second field current F ₂ is
As is clear from reference to b, the rotational torque T
The timing is set so that the application is applied to the field coil 2 at the time when the crank angle V, which fluctuates with a certain phase lag in the torque fluctuation, suddenly rises and reaches its peak. In other words, the delay time τ set in the delay circuit 10
are the peak of rotational torque T and crank angular speed
Set to approximately correspond to the phase difference between the peaks of V〓.

As mentioned above, when the battery 14 is in the discharge state, if the timing of application is corrected so that the field current F ₂ is applied at peak times including the sudden increase in the crank angular velocity V, the amount of power generated by the alternator 1 can be adjusted. increases accordingly, and is slightly less effective in suppressing fluctuations in the rotational torque of the crankshaft. However, by increasing the amount of power generation, the discharge state of the battery 14 is quickly resolved, and the alternator 1 is able to reduce the electrical load 6. In addition to supplying necessary and sufficient power, the battery 14 can be charged, and the battery 14 can be effectively prevented from rising.

As is clear from the above description, according to the present invention, the amount of power generated by the alternator can be increased by correcting the timing of applying field current during discharge while monitoring the discharge state of the battery. It is possible to effectively suppress fluctuations in the rotational torque of the output shaft while preventing the above-mentioned problems, and since it is only necessary to change the application timing of the field current, the configuration of the control system can be simplified.

[Brief explanation of drawings]

FIG. 1 is a block circuit diagram of a torque fluctuation suppressing device according to the present invention, and FIG. 2 is a timing chart showing the operation timing of the above circuit. 1... Alternator, 2... Field coil, 4... Driver circuit, 7... Crank angle sensor, 8... First waveform shaping circuit, 9... Switching circuit,
10...Delay circuit, 11...Second waveform shaping circuit,
12... Battery state detection means, 13... Monostable multivibrator, 14... Battery state detection means.

Claims (1)

[Claims] 1. A first timing signal generating means for detecting when the rotational torque fluctuation occurring at the output shaft increases in synchronization with an engine explosion and generating a timing signal at a first timing, and when the torque increases in the rotational torque fluctuation. A second timing signal is generated at a second timing delayed from the first timing when the rotational angular velocity of the output shaft reaches almost the peak by detecting the rotational angular velocity of the output shaft.
a timing signal generating means; a battery state detecting means for detecting a discharge state of the battery; 2. A torque fluctuation suppressing device for an engine, comprising: a field current control means for applying a field current at the timing of step 2.