JPH04300437A - Rotational zero point fifth-order dimensional oscillation reduction - Google Patents

Abstract

PURPOSE:To reduce rotational 0.5th order dimensional oscillation to be generated based on combustion variation of cylinders when an engine having a plurality of cylinders are idly operated or operated under a low load. CONSTITUTION:It is judged whether an engine 1 is under an idling condition or not from mean values of an engine speed and changing rate of the engine speed calculated from signals of a crank angle signal generation device 2. It is also judged whether the engine 1 is under a condition where 0.5th order dimensional oscillation reduction control is required or not. When the engine is under an idling condition where the 0.5th order dimensional oscillation reductrion control is required, an auxiliary equipment such as a load torque generation device 5 is used. The auxiliary equipment is controlled such that a battery voltage is a specified value and charging and discharging of electricity is balanced, so that the 0.5th order dimensional oscillation is reduced.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention reduces the 0.5th order vibration of engine rotation which occurs due to combustion variations in each cylinder during idling operation or low load operation of an engine having a plurality of cylinders. The present invention relates to a vibration reduction device at 0.5 rotation of a vehicle body suitable for improving ride comfort during idling of a vehicle.

0002

BACKGROUND OF THE INVENTION Engines installed in vehicles, such as diesel engines, which have a plurality of cylinders, are affected by so-called 0.5th-order rotational vibrations, which occur due to combustion variations in each cylinder, especially during idling. becomes noticeable. Conventionally, attention has not been paid to such 0.5-order vibration and efforts have not been made to actively reduce this vibration. As a prior art similar to this, there is an engine torque control device previously proposed by the applicant (Japanese Patent Laid-Open No. 63-212723).
. This torque control device suppresses torque fluctuations caused by combustion pressure fluctuations during operation, thereby reducing cylinder block vibration.

0003

As mentioned above, conventionally, there is no device for reducing the 0.5th order vibration that appears conspicuously when a diesel engine or the like is idling. in general,
The waveform characteristics of the rotational speed of an engine with multiple cylinders are
If there is variation in combustion status between cylinders, crank angle 72
The waveform has a number of fluctuation peaks equal to the number of cylinders during 0 degrees, and if there is no variation in the combustion state among the cylinders, the fluctuation peak disappears under the same load condition, and the waveform has approximately the same height. Incidentally, the amount of fuel supplied, which is one of the factors that determines the combustion state, is not always the same amount supplied to all cylinders. For example, in a gasoline engine, the amount of fuel in a particular cylinder may decrease depending on the shape of the intake manifold in the carburetor, etc., and even when distributing fuel by injection, the fuel flow characteristics may vary depending on the initial characteristics of the injector and changes over time. There may be variations in the amount of fuel in a particular cylinder. Furthermore, even in diesel engines, there are variations in the flow rate characteristics of the injection pump and injector, so the amount of fuel in a particular cylinder may decrease.

[0004] In this way, in an engine having a plurality of cylinders, if variations occur in the amount of fuel supplied to the cylinders, variations in the combustion state will occur among the cylinders, and this will generate 0.5-order vibration. Specifically, combustion in a particular cylinder is always strong or weak, causing variations in engine torque and vibration of the engine in the roll direction around the axle. For example, in a four-cylinder engine, if its rotational speed is 750 rpm, the excitation period is 160 ms and its frequency is 6.2 Hz. Since this frequency is a vibration frequency close to the roll eigenvalue of the engine, the engine resonates in the roll direction. Also,
In the case of an FR vehicle, not only the engine but also the vehicle body resonates in the roll direction. In this way, 0.5th order vibration is generated. Such 0.5th-order vibrations are especially noticeable to the occupants when the engine is idling, giving the occupants a very unpleasant feeling and making the ride of the vehicle worst.

[0005] To solve the above-mentioned problem of ride comfort, if the variation in the amount of fuel supplied to each cylinder is eliminated, the 0.5th order vibration can be eliminated and the ride comfort will be improved. For example, in a gasoline engine, it is possible to eliminate the 0.5-order vibration to some extent by adjusting the fuel injection amount for each cylinder using electronic control. However, electronic control is difficult for diesel engines, so traditionally, adjusting the variation in fuel supply amount for each cylinder has been a process of combining an injection pump and injector, examining their flow characteristics, and then changing the combination and readjusting. I was doing it repeatedly.

As mentioned above, efforts have been made to improve ride comfort by reducing the 0.5th order vibration, but in the past, the adjustment was troublesome and inefficient.
It cannot be said that the 0.5th order vibration was effectively reduced. In addition, this 0.5th order vibration reduction control is necessary in the idle state, but conventionally the configuration uses an idle switch, mission switch, etc. to detect whether or not it is in the idle state, which requires a large number of parts. There is a problem.

A first object of the present invention is to provide a rotational 0.5-order vibration reduction device that does not require switches for idle detection.

A second object of the present invention is to provide a rotational 0.5th order vibration reduction device that can directly suppress the 0.5th order vibration itself.

[0009]

[Means for Solving the Problems] The above first object is applied to an engine having a plurality of cylinders, detects parameters caused by variations in the combustion state of each cylinder, and applies load torque to the output shaft of the engine. In the rotational 0.5th order vibration reduction device that controls the torque generating means according to the value of the parameter to suppress the rotational 0.5th order vibration caused by the variation in the combustion state, the average value of the engine rotational speed and the rotational speed This is achieved by determining whether or not to perform control to suppress the 0.5th order vibration, based on the average value of the fluctuation amounts.

The second object is to suppress 0.5-order vibration by using an auxiliary machine as a torque generating means and controlling the auxiliary machine to balance charging and discharging so that the battery voltage becomes a predetermined voltage. This will be achieved.

[0011]

[Function] By using the average value of the rotational speed and the average value of the speed fluctuation amount, it is possible to determine whether or not it is in the idle state, and 0.5th order vibration suppression control is required without using an idle switch etc. This makes it possible to determine the appropriate operating range.

[0012] In addition, since the configuration uses an auxiliary machine to reduce the 0.5th order vibration, that is, the auxiliary machine is connected to the engine output shaft and can load torque to the output shaft. It becomes possible to suppress the 0.5th order vibration.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a principle diagram of a rotational 0.5-order vibration reduction device according to an embodiment of the present invention. As shown in Figure 1, the rotation is 0.
．． The fifth-order vibration reduction device is used in an engine 1 having multiple cylinders.
, a crank angle signal generator 2 that generates a signal synchronized with the crank angle, and the crank angle signal (POS signal, R
A rotational speed detection device 3 detects the rotational speed N of the engine 1 using the EF signal), and a crank angle is determined for each of the plurality of cylinders based on the change in the rotational speed detection value N outputted by the rotational speed detection device 3. Find the speeds in two sections within an angle of ±720 degrees/4M (M is the number of cylinders) sandwiching the angle at which the synchronized combustion torque is maximum, calculate the speed difference α, and determine the idle state of the engine 1 signal s5. a detection device 7 that outputs a signal, and an arithmetic processing device 4 that determines the combustion variation state of a plurality of cylinders from the output signal of the detection device 7 and creates a control signal based on the idle determination signal s5,
The engine 1 includes a load torque generator 5 that receives this control signal and generates a load on the crankshaft of the engine 1. engine 1
is an arbitrary type of engine such as a gasoline engine or a diesel engine, and the number of cylinders thereof is also arbitrary. For example, in the case of a four-cylinder engine, the two sections described above will occur within ±45 degrees of the angle at which the maximum combustion torque is generated. Note that the arithmetic processing device 4 includes a backup memory 6, and this memory 6 stores various data prepared in advance and predetermined data calculated by the arithmetic processing device 4.

As the load torque generating device 5, one of various auxiliary machines connected to the crankshaft of the engine 1 through a power transmission mechanism is used. In this embodiment, an alternator with good controllability is used as the load torque generating device. When controlling the load with an alternator, a field current control method and a generated current control method can be used, but in this embodiment, a field current control method that requires low current control is adopted.

FIG. 2 is a block diagram of a rotational 0.5-order vibration reduction device using an alternator as the load torque generating device 5. As shown in FIG. In FIG. 2, 10 is a crank pulley fixed to the crankshaft, 11 is a pulley connected to the crank pulley 10 by a belt 12, and the rotation center of the pulley 11 is the same as the rotation center of the rotor coil 13 of the alternator 5A and the shaft 14. connected. The rotation of the crankshaft is detected by a crank angle sensor 2a, which is a crank angle signal generating device, and the detection signal is input to the arithmetic processing device 4.

The alternating current generated in the rotor coil 13 of the alternator 5A is rectified by the rectifier 15, and then connected to the battery 16.
and is supplied to the IC regulator 14 and power section 18. The IC regulator 17 adjusts the input voltage to the field winding 1.
The required field current is supplied to 9. The power section 18 amplifies the control signal calculated by the arithmetic processing device 4 using a power transistor and supplies the amplified control signal to the field winding 19 . In this way,
Alternator 5A acts as a load torque generator.

The detection device 7 shown in FIG. 1 receives the signal from the crank angle signal generator 2, and detects the rotational speed fluctuation amount α generated corresponding to the engine rotational speed N and the combustion torque for each cylinder of the engine. At the same time, it also outputs an idle determination signal s5 for determining whether or not to perform 0.5-order vibration reduction control based on the average value of the rotational speed N and the average value of the rotational speed fluctuation amount α. Specifically, in the current engine control, the rotational speed is controlled to be constant when the engine is idling, so by looking at the rotational speed N, it can be determined whether or not the engine is substantially idling. However, when a load such as a transmission is connected, this idle rotation speed may be reached, so in this embodiment, at a low rotation speed near idle,
It is determined whether or not the engine is in an idling state by also looking at the rotational speed fluctuation amount α, which is approximately proportional to the combustion torque of the engine.

Next, alternator field current control in this embodiment will be explained with reference to the timing chart of FIG. As shown in FIG. 3, the control signal is an ON/OFF signal having a period of one cycle of the engine 1, and when it is ON, the field current rises, and when it is OFF, the field current If falls with a certain time constant. However, since the field current has a response delay, in order to create a sine wave-like waveform, the field current is It is necessary to control the slope of the falling edge of the curve. By doing this, the waveform of the generated current IL generated due to the field current If also becomes like a sine wave, and the waveform of the generated load torque also becomes like a sine wave. Note that small fluctuations in the generated current waveform occur due to rotational speed fluctuations for each cylinder.

Next, how to balance battery charging and discharging when performing 0.5th order vibration reduction control will be explained with reference to the flowchart shown in FIG. The way to balance charging and discharging is basically the same as the operation of a normal alternator IC regulator, which is to keep the battery voltage VB constant. Here, if the electrical load is extremely large, lowering this regulated voltage will reduce the
Makes N/OFF control easier. Furthermore, the battery voltage VB
However, as shown in FIG. 3, the control signal O
Using the voltage VB measured at the rising and falling positions of N, the average voltage is taken as the regulated voltage. The method of regulation will be explained according to the flowchart shown in FIG.

First, the average values of the battery voltage VB and the rotational speed fluctuation amount α are taken. Then, when the average value of the rotational speed fluctuation amount α is larger than the specified value, the maximum value Vmax and minimum value Vmin of the regulated voltage range are lowered. If the average value of α is within the specified value range, the previous maximum value Vmax and minimum value Vmin are used. Changing the regulated voltage range in this way is a measure against flicker. Next, it is determined whether the captured battery voltage VB is larger than the maximum value Vmax, and if it is larger, the average generated current is lowered so that the voltage VB is within the specified value range. do. The captured battery voltage VB is the minimum value Vmi above.
If it is smaller than n, the average generated current is increased so that the voltage VB is within the specified value range. One way to increase or decrease the generated current is to turn on the control signal.
There are two methods: one method is to change the pulse width of the switching section, and the other is a method of changing the pulse width of the switching section. In this embodiment, the pulse width of the switching section is first adjusted in consideration of the effect of vibration control. However, this adjustment method does not allow the generated current to exceed a certain specified value, so in that case, the pulse width when the control signal is turned ON is changed.

Next, a method for determining the control phase for the 0.5th rotational vibration will be explained with reference to the flowchart of FIG. First, the control flag (which is ON during this control) is set to O.
Determine whether it is N or not. When the control flag is OFF, the rotational speed fluctuation amount α is averaged for each cylinder, and the control phase is calculated from that value. Then, the control phase is stored in memory. The rotational speed fluctuation amount α is determined by the control obtained when no control is being performed, since the torque fluctuation generated by this control when executing 0.5-order vibration control also appears in this α, that is, it appears as an error. Phase or exact 0
．． The fifth-order component is stored in memory, and the stored control phase is read out and used during control.

When the control flag is ON, the IC regulator of the alternator is stopped, and alternator field current control using 0.5-order vibration reduction control is started. next,
As described above, the rotational speed fluctuation amount α is averaged for each cylinder, and the control phase is calculated from that value. This is to check whether the control phase has shifted significantly due to other factors. If the control phase has shifted significantly, the 0.5-order vibration control is immediately stopped and the IC regulator of the alternator is operated. If there is no control phase shift or it is small,
The control phase stored in the memory is read out and field current control is performed using the control phase to reduce the 0.5th order vibration.

FIG. 6 shows α for each cylinder for determining the control phase.
FIG. 3 is an explanatory diagram of a detection method. The α detection method for each cylinder includes a method of calculating the rotational speed fluctuation amount α from two interval pulse signals for each cylinder (Fig. 6 (a)), and a method of capturing the ring gear signal of the transmission as an angle signal and detecting the rotation speed fluctuation amount α from two interval pulse signals for each cylinder. There is a method of finding α from the signal that comes with one pulse (FIG. 6(b)), and a method of finding α only from the ring gear signal (FIG. 6(c)).

In the method of FIG. 6(a), as shown in FIG.
First, the cylinder number i is taken and the rotational speed N1 is calculated by measuring the pulse width in that cylinder. The rotation speed N2 is calculated by the next pulse width measurement. Then, the difference between the higher and lower rotation speeds is taken as the rotation speed fluctuation amount α for that cylinder, stored in the memory for each cylinder, and the cylinder number i is incremented to find α for the next cylinder.

In the method of FIG. 6(b), as shown in FIG.
Every time a signal for each cylinder arrives, the rotation speed at the specified low rotation measurement position (bottom) and the rotation speed at the high rotation measurement position (top) are calculated, and the difference is taken and stored as α for each cylinder. Store in. However, in this case, it is assumed that the rotational speed is captured for each ring gear signal and stored in the memory, and that there is rotational speed data for one cylinder between the cylinder signals.

In the method of FIG. 6(c), as shown in FIG.
In addition to capturing the rotation speed each time a ring gear signal arrives, it also detects where the reference position for measuring α is, and uses the lowest rotation speed as a reference to determine the specified low rotation measurement position and high rotation speed measurement position. The rotational speed at the rotational measurement position is calculated, the difference between the two is calculated, and the difference is stored in the memory as α for each cylinder.

[0027]

[Effects of the Invention] According to the present invention, the following effects are achieved. The variation in the strength of combustion in each cylinder is detected based on fluctuations in engine speed, etc., and period information of the 0.5th order vibration generated in the engine is extracted based on the variation in combustion state, and based on this period information, A control periodic wave signal for canceling the vibration is generated, its phase and amplitude are adjusted so as to reduce variations in the combustion state, and the periodic wave signal is used to generate load torque on the auxiliary equipment. Therefore, the 0.5th order vibration can be effectively suppressed, thereby eliminating the rolling motion of the vehicle and improving the riding comfort especially when the engine is idling.

[Brief explanation of the drawing]

FIG. 1 is a principle diagram of a rotational 0.5-order vibration reduction device in an embodiment of the present invention.

FIG. 2 is a configuration diagram of a rotational 0.5-order vibration reduction device.

FIG. 3 is a timing chart illustrating alternator field current control.

FIG. 4 is a flowchart for performing battery charge/discharge balance control.

FIG. 5 is a flowchart of how to obtain a control phase.

FIG. 6A, FIG. 6B, and FIG. 6C are explanatory diagrams of how to obtain the rotational speed fluctuation amount α for each cylinder, respectively.

FIG. 7 is a flowchart of how to obtain α in FIG. 6(a).

FIG. 8 is a flowchart of how to obtain α in FIG. 6(b).

FIG. 9 is a flowchart of how to obtain α in FIG. 6(c).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1...Engine, 2...Crank angle signal generation device, 3...Rotational speed detection device, 4...Arithmetic control device, 5...Load torque generation device, 6...Backup memory, 7...α,N detection device.

Claims (13)

[Claims] 1. Applicable to an engine having a plurality of cylinders, the method detects a parameter caused by variations in the combustion state of each cylinder, and generates a torque generating means for applying a load torque to an output shaft of the engine according to the value of the parameter. In the rotational 0.5th order vibration reduction device that controls and suppresses the rotational 0.5th order vibration due to the variation in the combustion state, the average value of the engine rotational speed and the average value of the amount of variation in the rotational speed are set to 0.
．． A rotational 0.5th order vibration reduction device, characterized in that it determines whether or not to perform control to suppress fifth order vibrations. 2. The present invention is applied to an engine having a plurality of cylinders, detects parameters caused by variations in the combustion state of each cylinder, and controls the torque generating means for applying a load torque to the output shaft of the engine according to the value of the parameter. In the rotational 0.5th order vibration reduction device that controls and suppresses vibrations due to variations in the combustion state, an auxiliary machine is used as the torque generating means, and the auxiliary machine is configured to balance charging and discharging so that the battery voltage becomes a predetermined voltage. A rotational 0.5th order vibration reduction device characterized by controlling a machine to suppress 0.5th order vibrations. 3. The present invention is applied to an engine having a plurality of cylinders, detects a parameter caused by variations in the combustion state of each cylinder, and determines the field current or generated current of an alternator that applies a load torque to the output shaft of the engine according to the parameter. In the rotational 0.5th order vibration reduction device that controls according to the value of and suppresses vibrations due to variations in the combustion state, the vibration suppression control is controlled to balance charging and discharging so that the battery voltage becomes a predetermined voltage. Rotation 0.5 characterized by
Next vibration reduction device. 4. The predetermined voltage according to claim 2 or 3, wherein the predetermined voltage is changed according to an average value of engine speed fluctuations during idling.
Next vibration reduction device. 5. The rotational 0.5-order vibration reduction device according to claim 3 or 4, wherein an IC regulator of the alternator is stopped during vibration suppression control. 6. According to any one of claims 3 to 5, the detection of the battery voltage is performed at the timing of rising and falling of a signal for turning on the vibration suppression control. Reduction device. 7. According to any one of claims 3 to 6, when the vibration suppression control is turned off, switching is performed using a PWM signal to change the falling slope of the field current. Fifth order vibration reduction device. 8. The 0.5-order rotation according to any one of claims 3 to 7, characterized in that the control phase is adjusted by using the fall timing of an on-off signal that controls the field current as a load torque peak value. Vibration reduction device. 9. According to any one of claims 1 to 8, the detection of the combustion state is performed using only two rotation speed measurement period pulses sandwiching the combustion torque peak of each cylinder. Next vibration reduction device. 10. In any one of claims 1 to 8, the combustion state is detected using a signal generated at every fixed rotation angle and a signal generated one pulse in synchronization with the combustion stroke of each cylinder. A rotational 0.5th order vibration reduction device characterized by: 11. According to any one of claims 1 to 8, the combustion state is detected using only angle signal pulses that are continuously generated at every predetermined rotation angle within one combustion cycle. Rotational 0.5th order vibration reduction device. 12. In any one of claims 1 to 11, the control phase is determined from the amount of rotational speed variation determined without applying a load torque due to the vibration suppression control,
A rotational 0.5-order vibration reduction device characterized by performing vibration suppression control using this control phase. 13. According to any one of claims 1 to 12, it is determined whether or not the torque fluctuation period has changed based on the amount of rotational speed fluctuation obtained with a load torque applied by vibration suppression control. Rotational 0.5th order vibration reduction device.